BOOK REVIEW IN COMMUNICATIONS Electronic Communications System By Wayne Tomasi

INTRODUCTION TO ELECTRONIC
CHAPTER 1 COMMUNICATIONS

# DEFINITIONS TERMS

Its fundamental purpose is to transfer information from Electronic

1)
one place to another. Communication System

The transmission, reception, and processing of

Electronic
2) information between two or more locations using
Communication
electronic circuits.

Electronic Communications Time Line

1830: American Scientist and professor Joseph Henry transmitted the first
practical electrical signal.

1837: Samuel Finley Breese Morse invented the telegraph.

1843: Alexander Bain invented the facsimile.

1861: Johann Phillip Reis completed the first nonworking telephone.

1864: James Clerk Maxwell released his paper “Dynamic Theory of the
Electromagnetic Field”, which concluded that light electricity,
and magnetism were related.
3)
1865: Dr. Mahlon Loomis became the first person to communicate wireless
through the Earth’s atmosphere.

1866: First transatlantic telegraph cable was installed.

1876: Alexander Graham Bell and Thomas Watson Invented the telephone.

1877: Thomas Alva Edison invents the phonograph.

1880: Heinrich Hertz discovers electromagnetic waves.

1887: Heinrich Hertz discovers radio waves. Marchese Guglielmo Marconi

demonstrates wireless radio wave propagation.

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BOOK REVIEW IN COMMUNICATIONS Electronic Communications System By Wayne Tomasi

1888: Heinrich Hertz detects and produces radio waves. Heinrich Hertz
conclusively proved Maxwell’s prediction that electricity can travel
in waves through the Earth’s atmosphere.

1894: Marchese Guglielmo Marconi builds his first radio equipment, a device
that rings a bell from 30 ft. away.

1895: Marchese Guglielmo Marconi discovered ground wave propagation.

1898: Marchese Guglielmo Marconi established the first radio link between
England and France.

1900: American Scientist Reginald A. Fessenden the world’s first radio broadcast
using continous waves.

1901: Marchese Guglielmo Marconi transmits telegraphic radio messages from

Cornwall, to Newfoundland.
Reginald A. Fessenden transmits the World’s first radio broadcast using
continuous waves. First successful transatlantic transmission of
radio signal.

1903: Valdemar Poulsen patents an arc transmission that generates continuous

wave transmission 100-kHz signal that is receivable 150 miles away.

1904: First radio transmission of music at Graz, Austria.

1905: Marchese Guglielmo Marconi invents the directional radio antenna.

1906: Reginald A. Fessenden invents amplitude modulation (AM).

First radio program of voice and music broadcasted in the United States
by Reginald Fessenden.
Lee DeFrorest invents triode (three-electrode) vacuum tube.

1907: Reginald Fessenden invents a high- frequency Electric generator that

produces radio waves with a frequency of 100 kHz.

1908: General Electric develops a 100-kHz, 2-kW alternator for radio

communications.

1910: The Radio Act of 1910 is the first concurrence of government regulation of
radio technology and services.

1912: The Radio Act of 1912 in the United States brought order to the radio
bands by requiring station and operators licenses and assigning
blocks of the frequency spectrum to the existing users.

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1913: The cascade-tuning radio receiver and the heterodyne receiver are
introduced.

1914: Major Edwin Armstrong develops the superheterodyne radio receiver.

1915: Vacuum-tube radio transmitters introduced.

1919: Shortwave radio is developed.

1920: Radio Station KDKA broadcasts the first regular licensed radio transmission
out of Pittsburgh, Pennsylvania.

1921: Radio Corporation of America (RCA) begins operating Radio Central on

Long Island. The American Radio League establishes contact
via shortwave radio with Paul Godley in Scotland, proving that shortwave
radio can be used for long distance communications.

1923: Vladimir Zworykin invents and demonstrates television.

1927: A temporary five- member Federal Radio Commission agency was

created in the United States.

1928: Radio station WRNY in New York City begins broadcasting television shows.

1931: Major Edwin Armstrong patents wide- band frequency modulation (FM).

1934: Federal Communications Commission (FCC) created to regulate

telephone, radio, and television broadcasting.

1935: Commercial FM radio broadcasting begins with monophonic transmission.

1937: Alec H. Reeves invents binary coded pulse-code modulation. (PCM)

1939: National Broadcasting Company (NBC) demonstrates television

broadcasting. First use of two-way radio communications
using walkie-talkies.

1941: Columbia University Radio Club opens the first regularly scheduled FM
radio station.

1945: Television is born. FM moved from its original home of 42 MHz to 50 MHz to
88 MHz to 108 MHz to make room.

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1946: The American Telephone and Telegraph Company (AT&T) inaugurated

the first mobile telephone system for the public called MTS
(Mobile Telephone System).

1948: John Von Neumann created the first store program electronic digital
computer. Bell Telephone Laboratories unveiled the transistor, a joint
venture of scientist William Shockley, John Bardeen and Walter Brattain.

1951: First transcontinental microwave system began operation.

1952: Sony Corporation offers a miniature transistor radio, one of the first mass
produced consumer AM/FM radios.

1953: RCA and MBC broadcast first color television transmission.

1954: The number of radio stations in the world exceeds the number of
newspapers printed daily.

1954: Texas Instruments becomes the first company to commercially produce

silicon transistors.

1956: First transatlantic telephone cable systems began carrying calls.

1957: Russia launches the world’s first satellite. (Sputnik)

1958: Kilby and Noyce develop first integrated circuits.

NASA launched the United States first satellite.

1961: FCC approves FM stereo broadcasting, which spurs the development of

FM. Citizens band (CB) radio first used.

1962: U.S. radio stations begin broadcasting stereophonic sound.

1963: T1 (transmission 1) digital carrier systems introduced.

1965: First commercial communications satellite launched.

1970: High-definition television (HDTV) introduced in Japan.

1977: First commercial use of optical fiber cables.

1983: Cellular telephone networks introduced in the United States.

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1999: HDTV standards implemented in the United States.

1999: Digital Television (DTV) transmission began in the United States.

Are time-varying voltages or currents that are

4) analog signals
continuously changing such as sine and cosine waves.

5) Is sometimes referred to as a power loss. Attenuation

Is sometimes referred to as a ____________ , If Pout = Pin,

6) the absolute power gain is 1, and the dB power gain is Unity Power Gain
0 dB.

Are voltages or currents that change in discrete steps

7) digital signals
or levels.

In 1876, Alexander Graham Bell and Thomas A. Watson

were the first to successfully transfer human
8) Telephone
conversation over a crude metallic- wire
communications systems using this device.

The first commercial radio broadcasting station in 1920

9) that broadcasted amplitude modulated signals in KDKA
Pittsburgh.

10) Is a logarithmic unit that can be used to measure ratio. Decibel ( dB )

Is a unit of measurement used to indicate the ratio of a

11) power level with respect to a fixed reference level dBm
(1mW).

12) One-tenth of a decibel. Bel

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A collection of one or more electronic devices or

circuits that converts the original source information to
13) Transmitter
a form more suitable for transmission over a particular
transmission medium.

Provides a means of transporting signals between a

14) Transmission Medium
transmitter and a receiver.

A collection of electronic devices and circuits that

accepts the transmitted signals fro the transmission
15) Receiver
medium and then converts those signals back to their
original form.

Is any unwanted electrical signals that interfere with the

16) System Noise
information signal.

Because it is often impractical to propagate

information signals over standard transmission media,
17) Carrier
it is often necessary to modulate the source information
onto a higher-frequency analog signal called a ______.

The process of changing one or more properties of the

18) Modulation
analog carrier in proportion with the information signal.

A system in which energy is transmitted and received in

Analog Communication
19) analog form (a continuously varying signals such as a
System
sine wave).

A true digital system where digital pulses (discrete levels

20) such as +5V and ground) are transferred between two Digital Transmission
or more points in a communications system.

The transmittal of digitally modulated analog carriers

between two or more points in a communications
21) digital radio
system.

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A modulation technique where the information signal is

Amplitude Modulation
22) analog and the amplitude (V) of the carrier is varied
( AM )
proportional to the information signal.

A modulation technique where the information signal is

Frequency Modulation
23) analog and the frequency (f) of the carrier is varied
( FM )
proportional to the information signal.

A modulation technique where the information signal is

24 analog and the phase () of the carrier is varied Phase Modulation
proportional to the information signal.

A modulation technique where the information signal is

Amplitude Shift Keying
25) digital and that amplitude (V) of the carrier is varied
( ASK )
proportional to the information signal.

A modulation technique where the information signal is

Frequency Shift Keying
26) digital and the frequency (f) of the carrier is varied
( FSK )
proportional to the information signal.

A modulation technique where the information signal is

Phase Shift Keying
27) digital and the phase () of the carrier is varied
( PSK )
proportional to the information signal.

A modulation technique where both the amplitude Quadrature Amplitude

28) and the phase of the carrier are varied proportional to Modulation
the information signal. ( QAM )

Modulation is performed in a transmitter by a circuit

29) Modulator
called ________.

The reverse process of modulation and converts the

30) modulated carrier back to the original information Demodulation

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BOOK REVIEW IN COMMUNICATIONS Electronic Communications System By Wayne Tomasi

Demodulation is performed in a receiver by a circuit

31) Demodulator
called _______.

2 Reasons why modulation is necessary in electronic communications :

1. It is extremely difficult to radiate low-frequency signals from an antenna in

the form of electromagnetic energy.
32)
2. Information signals often occupy the same frequency band and, if signals
from two or more sources are transmitted at the same time, they would
interfere with each other.

A specific band of frequencies allocated a particular

33) Channel
service.

Process of converting a frequency or band of

33) frequencies to another location in the total frequency Frequency Translation
spectrum.

The purpose of an electronic communications system is

34) to communicate information between two or more Stations
locations commonly called _____________ .

The number of times a periodic motion, such as a sine

35) wave of voltage or current, occurs in a given period of Frequency
time.

36) Each complete alternation of the waveform. Cycle

Is an international agency in control of allocating International

37) frequencies and services within the overall frequency Telecommunications
spectrum. Union ( ITU )

Federal
In the United States, assigns frequencies and
38) Communications
communications services for free-space radio
Commission ( FCC )
propagation.

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39)

Are signals in the 30Hz to 300Hz range and include ac

Extremely Low
40) power distribution signals (60Hz) and low frequency
Frequencies ( ELF )
telemetry signals.

Are signals in the 300Hz to 3000Hz range and include Voice Frequencies
41)
frequencies generally associated with human speech. ( VF )

Are signals in the 3kHz to 30kHz range which include the

Very Low Frequencies
42) upper end of the human hearing
( VLF )
range.

Are signals in the 30kHz to 300kHz range and are used Low Frequencies
43)
primarily for marine and aeronautical navigation. ( LF )

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Are signals in the 300kHz to 3MHz range and are used

Medium Frequencies
44) primarily for commercial AM radio broadcasting
( MF )
(535kHz-1605kHz).

Are signals in the 3MHz to 30MHz range and are often

High Frequencies
45) referred to as short waves. Used for most two-way
( HF )
radio communications.

Are signals in the 30MHz to 300MHz range and are used

for mobile radio, marine and aeronautical
Very High Frequencies
46) communications, commercial FM broadcasting (88 to
( VHF )
108MHz) and commercial TV broadcasting of Ch 2 to
13 (54MHz to 216MHz).

Are signals in the 300MHz to 3GHz range and are used

by commercial television broadcasting of channels 14
Ultrahigh Frequencies
47) to 83, land mobile communications services, cellular
( UHF )
telephones, certain radar and navigation systems, and
microwave and satellite radio systems.

Are signals in the 3GHz to 30GHz range and include the

Super High Frequencies
48) majority of the frequencies used for microwave and
( SHF )
satellite radio communications systems.

Are signals in the 30GHz to 300GHz range and are Extremely High
49) seldom used for radio communications except in very Frequencies
sophisticated, expensive, and specialized applications. ( EHF )

Are signals in the 0.3THz to 300THz range and are not

generally referred to as radio waves. Used in heat
50) Infrared
seeking guidance systems, electronic photography,
and astronomy.

Includes electromagnetic frequencies that fall within

51) Visible Light
the visible range of humans (0.3PHz to 3PHz).

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Light-wave
52) Used for optical fiber systems.
Communications

The length that one cycle of an electromagnetic wave

53) occupies in space (i.e., the distance between similar Wavelength
points in a repetitive wave).

ELECTROMAGNETIC WAVELENGTH SPECTRUM

54)

Radio transmitter classifications according to

55) bandwidth, modulation scheme, and type of Emission Classifications
information.

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56)

 The first symbol is a letter that designates the type of modulation of the
main carrier.
 The second symbol is a number that identifies the type of emission.
 The third symbol is another letter that describes the type of information
being transmitted.

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The two most significant limitations on the performance

57) of a communications system are ________and ________. Noise and Bandwidth

The difference between the highest and lowest

58) Bandwidth
frequencies contained in the information.

The bandwidth of a communications channel is the

difference between the highest and lowest
59) Passband
frequencies that the channel will allow to pass
through it.

A highly theoretical study of the efficient use of

60) bandwidth to propagate information through Information Theory
electronic communications systems.

The measure of how much information can be

61) propagated through a communications system and is Information Capacity
a function of bandwidth and transmission time.

The most basic digital symbol used to represent

62) Binary Digit / Bit
information.

The number of bits transmitted during one second and

63) is expressed in bits per second (bps). Bit Rate

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In 1928, R. Hartley of Bell Telephone Laboratories Hartley’s Law

64) developed a useful relationship among bandwidth,
transmission time, and information capacity. IBxt

Shannon limit for

information capacity

In 1948, mathematician Claude E. Shannon published

a paper in the Bell System Technical Journal relating
65)
the information capacity of a communications
channel to bandwidth and signal-to-noise ratio. OR

Any undesirable electrical energy that falls within the

66) Electrical Noise
passband of the signal.

67) Noise present regardless of whether there is a signal Uncorrelated Noise

present or not.

68) Noise that is generated outside the device or circuit. External Noise

Noise that is naturally occurring electrical disturbances

69) Atmospheric Noise
that originate within Earth’s atmosphere.

70) Atmospheric noise is commonly called ____________ . Static Electricity

Noise consists of electrical signals that originate from

71) outside Earth’s atmosphere and is sometimes called Extraterrestrial Noise
deep-space noise.

72) Extraterrestrial noise is sometimes called ____________ . Deep-Space Noice

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73) Noise generated directly from the sun’s heat. Solar Noise

Noise sources that are continuously distributed

65) Cosmic Noise
throughout the galaxies.

66) Noise that is produced by mankind. Man-made Noise

Electrical interference generated within a device or

67) Internal Noise
circuit.

Noise caused by the random arrival of carriers (holes

68) and electrons) at the output element of an electronic Shot Noise
device.

Any modification to a stream of carriers as they pass

69) from the input to the output of a device produces an Transit-time Noise
irregular, random variations.

Associated with the rapid and random movement of

70) Thermal Noise
electrons within a conductor due to thermal agitation.

THERMAL AGITATION HAS SEVERAL NAMES, INCLUDING :

 Thermal Noise, because it is temperature dependent;

71)  Brownian Noise, after its discoverer;
 Johnson Noise, after the man who related Brownian particle movement of
electron movement;
 White Noise, because the random movement is at all frequencies;

Johnson proved that thermal noise power is Noise Power

72) proportional to the product of bandwidth and
temperature. N = KTB

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A form of internal noise that is correlated (mutually

related) to the signal and cannot be present in a
73) Correlated Noise
circuit unless there is a signal.
“ no signal, no noise! “

Occurs when unwanted harmonics of a signal are

74) produced through nonlinear amplification (nonlinear Harmonic Distortion
mixing).

The generation of unwanted sum and difference

Inter-modulation
75) frequencies produced when two or more signals mix in
Distortion
a nonlinear device.

The original signal and also called the fundamental

76) First Harmonic
frequency.

77) A frequency two times the original signal frequency. Second Harmonic

78) A frequency three times the original signal frequency. Third Harmonic

79) Another name for harmonic distortion. Amplitude Distortion

Characterized by high-amplitude peaks of short

80) Impulse Noise
duration in the total noise spectrum.

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81)

A form of external noise and as the name implies it

82) Interference
means to disturb or detract form.

Noise produced when information signals from one

source produce frequencies that fall outside their
83) Electrical interference
allocated bandwidth and interfere with information
signals from another source.

Signal-to-Noise Power
Ratio ( S/N )

The ratio of the signal power level to the noise power

84)
level.

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Noise Factor ( F )
Figures of merit used to indicate how much the signal-
85) and
to-noise ratio deteriorates as a signal passes through a
Noise Figure ( NF )
circuit or series of circuits

FORMULA OF NOISE FACTOR

86)

FORMULA FOR NOISE FIGURE

87)
NF ( dB ) = 10 log F

A convenient parameter often used rather than noise Equivalent Noise

figure in low noise, sophisticated VHF, UHF, microwave, Temperature
88) and satellite radio receivers. It indicates the reduction ( Te )
in the signal-to-noise ratio a signal undergoes as it
propagates through a receiver. Te = T ( F – 1 )

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CHAPTER 2 SIGNAL ANALYSIS AND MIXING

# DEFINITIONS TERMS

Electrical signals of which amplitude changes

1) continuously with respect to time with no breaks or Analog Signals
discontinuities.

Electrical signals that are described as discrete; their

amplitude maintains constant level for a prescribed
2) Digital Signals
period of time and then it changes to another level
with respect to time with no breaks or discontinuities.

3) Digital signal with only two levels possible. Binary Signal

4) Digital signal with four levels possible. Quaternary Signal

Is the mathematical analysis of the frequency,

5) Signal Analysis
bandwidth, and voltage level of a signal.

6) A signal that repeats at a uniform rate. Periodic Wave

Time-domain
7) A description of signal with respect to time.
Representation

A time-domain instrument that shows signal

8) Oscilloscope
waveforms.

The display on the cathode ray tube (CRT) that shows

9) Signal Waveform
the shape and instantaneous magnitude of the signal
with respect to time.

A description of signal with respect to its frequency. Frequency Domain

10)
Representation

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A frequency-domain instrument that shows

11) Spectrum Analyzer
amplitude-versus-frequency plot.

Any repetitive wave that is comprised of more than Nonsinusoidal /

12)
one harmonically related sine or cosine wave. Complex Wave

A mathematical series developed in 1826 by French

13) physicist and mathematician Baron Jean Fourier used Fourier Series
to analyze complex periodic wave.

A mathematical tool that allows us to move back

and forth between the time and frequency domains.
14) Fourier Series
It is used in signal analysis to represent the sinusoidal
components of nonsinusoidal periodic waveforms.

Waveform comprised of an average dc component

15) and a series of harmonically related sine or cosine Periodic Waveform
wave.

16) Is the integral multiple of the fundamental frequency. Harmonic

Is the first harmonic and is equal to the frequency

17) Fundamental Frequency
(repetition rate) of the waveform.

If a periodic voltage waveform is symmetric about

18) the vertical axis, it is said to have axes, or even function
mirror, symmetry and is called an ________.

If a periodic voltage waveform is symmetric about a

line midway between the vertical axis and the
negative horizontal axis and passing through the
coordinate origin, it is said to have point, or skew,
19) odd function
symmetry is called an ______.

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If a periodic voltage waveform is such that the

waveform for the first half cycle repeats itself except
20) half-wave symmetry
with the opposite sign for the second half cycle, it is
said to have ________.

The ________ of a waveform consists of all the

frequencies contained in the waveform and their
21) frequency spectrum
respective amplitudes plotted in the frequency
domain.

The difference between the highest and lowest

frequencies contained in the information. It is also
Bandwidth of an
22) the difference between the highest and lowest
information signal
frequencies that the channel will allow to pass
through it.

The ratio of the active time of the pulse to the period

23) Duty Cycle
of the waveform.

The rate at which energy is dissipated, delivered, or

24) used, and is a function of the square of the voltage Electrical Power
or current

A fourier transform where a time-domain signal is

25) Discrete Fourier Transform
sampled at discrete times.

A new algorithm of fourier transform developed by

26) Cooley and Tukey in 1965 where the computing time Fast Fourier Transform
is proportional to n log 2n rather than n2 .

27) The process of combining two or more signals Mixing

Occurs when two or more signals combine in a linear

28) device, such as a passive network or a small-signal Linear Summing
amplifier. Also called linear mixing.

29) An amplifier where the output is simply the original Linear Amplifier
input signal amplified by its gain.

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Occurs when two or more signals are combined in a

30) nonlinear device such as a diode or large-signal Nonlinear Mixing
amplifier.

Undesired generation of multiples or harmonics of

31) Harmonic Distortion
that frequency.

Desired generation of multiples or harmonics of that

32) Frequency Multiplication
frequency.

The sum and difference of the two original

33) Cross Products
frequencies.

The generation of any unwanted cross-product

34) frequency when two or more frequencies are mixed Intermodulation Distortion
in a nonlinear device.

Desired cross products produced by mixing in a

35) Modulation
nonlinear device.

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OSCILLATORS, PHASE-LOCKED LOOPS, AND

CHAPTER 3 FREQUENCY SYNTHESIZERS

# DEFINITIONS TERMS

This word means to fluctuate between two states or

1) Oscillate
conditions.

A device that produces oscillations or generates

2) repetitive waveform. Converts a dc input voltage to Oscillator
an ac output voltage.

A self-sustaining oscillator where the changes in the

3) waveform are continuous and repetitive; they occur Free-running Oscillator
at a periodic rate.

Are oscillators that are not self-sustaining require an

Triggered or One-shot
4) external input signal or trigger to produce a change
Oscillators
in the output waveform.

An amplifier with a feedback loop or path for energy

5) Feedback
to propagate from the output back to the input.

According to this criterion, for a feedback circuit to

sustain oscillations, the net voltage gain around the
6) feedback loop must be unity or greater, and the net Barkhausen Criterion
phase shift around the loop must be a positive
integer multiple of 360 .

Is a positive feedback where the positive means that

7) its phase aids the oscillation process and does not Regenerative Feedback
necessarily indicate a positive or negative polarity.

Is a negative feedback and supplies a feedback

signal that inhibits oscillations from occurring.
8) Degenerative Feedback

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Is an untuned RC phase shift oscillator that uses both

positive and negative feedback. The oscillator that
9) Wien-bridge Oscillator
Hewlett and Packard used in their original signal
generator design.

Added to the circuit to compensate for imbalances

Automatic Gain Control
10) in the bridge and variations in component values
( AGC )
due to heat.

Are oscillator circuits that utilize LC tank circuits for the

11) LC Oscillators
frequency determining components.

12) An LC oscillator that uses a tapped coil. Hartley Oscillator

The operation of this oscillator is very similar to that of

13) Hartley except that a capacitive divider is used Colpitts Oscillator
instead of a tapped coil.

An oscillator circuit identical to the Colpitts except

14) Clapp Oscillator
with the addition of a small capacitor Cs placed in
series with L1.

The ability of an oscillator to remain at a fixed

15) Frequency Stability
frequency.

Frequency stability affected predominantly by

16) Short-term Stability
fluctuations in dc operating voltages.

Frequency stability which is a function of component

17) aging and changes in the ambient temperature and Long-term Stability
humidity.

Feedback oscillator circuits where a crystal is used for

the frequency determining component.
18) Crystal Oscillator

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The study of the form, structure, properties, and

classifications of crystals. It deals with lattices,
19) bonding, and behavior of slices of crystal material Crystallography
that have been cut at various angles with respect to
the crystal’s axes.

The _______ occurs when oscillating mechanical

20) stresses applied across a crystal lattice structure Piezoelectric Effect
generate electrical oscillations and vice versa.

In this mode the oscillator is tuned at the third, fifth,

21) seventh, or even the ninth harmonic of the crystal’s Overtone
fundamental frequency.

The direction of frequency change is the same as the Positive Temperature

22)
temperature change. Coefficient

The change in frequency is in the direction opposite Negative Temperature

23)
to the temperature change. Coeffiecient

Is almost a perfect zero-coefficient crystal from

24) freezing to boiling but is useful only at frequencies GT-cut Crystal
below a few hundred kilohertz.

A crystal oscillator circuit that has very good

25) Discrete Pierce Oscillator
frequency stability and reasonably simple circuitry.

A crystal oscillator circuit that has low cost and simple

26) IC-based Pierce Oscillator
digital interfacing capabilities.

A crystal oscillator circuit that has best frequency

27) RLC Half-bridge
stability.

Consists of a crystal-controlled oscillator and a

28) Crystal Oscillator Module
voltage-variable component such as a varactor
diode.

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A specially constructed diode whose internal

Varactor Diode
capacitance is enhanced when reversed biased,
29) or
and by varying the reverse-bias voltage, the
Varicap
capacitance of the diode can be adjusted.

An oscillator circuit that generates well-defined,

30) stable waveforms that can be externally modulated Waveform Generator
or swept over a given frequency range.

A monolithic function generator integrated circuit

manufactured by EXAR Corporation capable of
31) producing high quality sine, square, triangle, rap, and XR-2206
pulse waveforms with both a high degree of stability
and accuracy.

A free-running oscillator with a stable frequency of

Voltage Controlled
32) oscillation that depends on an external timing
Oscillator
capacitance, timing resistance, and control voltage.

A monolithic voltage controlled oscillator

(VCO) integrated circuit featuring excellent
frequency stability and a wide tuning range. The
33) XR-2207
circuit provides simultaneous triangle- and square-
wave outputs over a frequency range of from 0.01 Hz
to 1 MHz.

A monolithic variable-frequency oscillator circuit

34) featuring excellent temperature stability and a wide XR-2209
linear sweep range.

A closed-loop feedback control system in which

either the frequency or the phase of the feedback Phase Locked Loop
35)
signal is the parameter of interest rather than the ( PLL )
magnitude of the signal’s voltage or current.

The VCO’s output frequency when the PLL is not Preset/Natural Free-
36)
locked. Running Frequency

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The voltage produced by the phase comparator that

37) is proportional to the difference in frequency Error Voltage
between the two signals.

The PLL state when there is no external input

38) Free-Running State
frequency or the feedback loop is open.

The state when the PLL is in the process of acquiring

39) Capture State
frequency lock.

The state when the VCO output frequency is locked

40) onto (equal to) the frequency of the external input Lock State
signal.

41) The time required to achieve lock. Acquisition Time

The band of frequencies centered around the VCO

natural frequency where the PLL can initially establish
42) Capture Range
or acquire frequency lock with an external input
signal from an unlocked condition. Also known as
acquisition range.

43) The capture range expressed as a peak value. Pull-in Range

The band of frequencies centered around the VCO

natural frequency over which a PLL can maintain
44) Lock Range
frequency lock with an external input signal. Also
known as tracking range.

45) The lock range expressed as a peak value. Hold-in Range

An oscillator with a stable frequency of oscillation

that depends on an external bias voltage.
Voltage-Controlled
46)
Oscillator

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Sometimes called a phase detector which is a

47) nonlinear device with two input signals: an external Phase Comparator
input frequency and the VCO output signal.

The difference in phase between an external input

48) Phase Error
frequency and the VCO output signal.

The product of the individual gains or transfer

49) Loop Gain
functions around the loop for the PLL.

An ultra stable monolithic phase-locked-loop system

designed by EXAR Corporation for a wide variety of
applications in both analog and digital
50) XR-215
communications systems. Can operate over a
relatively wide frequency range from 0.5 Hz to 35
MHz.

51) PLL that are used to track digital pulses rather than Digital PLL
analog signals, such as in clock recovery circuits.

This word means to form an entity by combining parts

52) Synthesize
or elements.

Are used to generate many output frequencies

through the addition, subtraction, multiplication, and
53) Frequency Synthesizer
division, of a smaller number of fixed frequency
sources.

A method of frequency synthesis where multiple

output frequencies are generated by mixing the
Direct Frequency
54) outputs from two or more crystal-controlled
Synthesis
frequency sources or by dividing or multiplying the
output frequency from a single-crystal oscillator.

A method of frequency synthesis where a feedback-

Indirect Frequency
55) controlled divider/multiplier such as PLL is used to
Synthesis
generate multiple output frequencies.

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The minimum frequency separation between output

56) Resolution
frequencies for a synthesizer.

An advanced dual-modulus low-power, ECL

prescaler manufactured by Signetics Company. The
57) NE/SA701
maximum input signal frequency is 1.2 GHz for cellular
and other land mobile applications.

A bipolar, single-chip frequency synthesizer

manufactured in SUBILO-N technology (components
58) laterally separated by oxide). It performs all the TSA6057/T
tuning functions of a PLL radio-tuning system. Also
manufactured by Signetics.

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CHAPTER 4 AMPLITUDE MODULATION TRANSMISSION

# DEFINITIONS TERMS

The process of impressing low-frequency information

1) Modulation
signals onto a high-frequency carrier signal.

The reverse process of modulation where the

2) received signals are transformed back to their Demodulation
original form.

The process of changing the amplitude of a relatively

3) high frequency carrier signal in proportion with the Amplitude Modulation
instantaneous value of the modulating signal.

Frequencies that are high enough to be efficiently

4) radiated by the antenna and propagated through Radio Frequencies
free space.

The modulated output waveform from an AM

5) AM Envelope
modulator is?

6) Sometimes called conventional AM or simply AM. AM DSBFC

The band of frequencies between fc – fm(max)

7) Lower Sideband
and fc

Any frequency within the lower sideband is called.

8) Lower Side Frequency

The band of frequencies between fc and

9) Upper Sideband
fc + fm(max)

10) Any frequency within the upper sideband is called? Upper Side Frequency

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The term used to describe the amount of amplitude

11) change (modulation) present in an AM waveform Coefficient of Modulation
signal.

The coefficient of modulation stated as a

12) Percent Modulation
percentage.

The maximum percent modulation that can be

13) 100%
imposed without causing excessive distortion.

The _______ in a transmitter where modulation occurs

14) determines whether the circuit is a low or a high-level Location
transmitter

The modulation takes place prior to the output

15) Low-Level Modulation
element of the final stage of the transmitter.

The modulation takes place in the final element of

16) the final stage where the carrier signal is at its High-Level Modulation
maximum amplitude.

The amplitude of the output signal depends on the

17) amplitude of the input carrier and the voltage gain Emitter Modulation
of the amplifier.

A class C modulator capable of nonlinear mixing and

18) the modulating signal is applied directly to the Collector Modulator
collector.

Used to translate the low-frequency intelligence

signals to radio-frequency signals that can be
19) Up-converter
efficiently radiated from an antenna and
propagated through free space.

20) Are used for observing the modulation characteristics Trapezoidal Pattern
of AM transmitters.

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A form of amplitude distortion introduced when the

positive and negative alternations in the AM
21) Carrier Shift
modulated signal are not equal (nonsymmetrical
modulation).

Complex waveforms comprised of two or more

22) Nonsinusoidal Signals
frequencies.

Are complex waves made up of two or more

Complex Repetitive
23) harmonically related sine waves and include square,
Waveforms
rectangular, and triangular waves.

A form of AM where signals from two separate

information sources modulate the same carrier
frequency at the same time without interfering with Quadrature Amplitude
24) each other. The information sources modulate the Modulation
same carrier after it has been separated into two ( QAM )
carrier signals that are 90 out of phase with each
other.

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CHAPTER 5 AMPLITUDE MODULATION RECEPTION

# DEFINITIONS TERMS

1) The reverse process of AM modulation. AM Demodulation

The first stage of the receiver of which primary

2) functions are detecting, band limiting, and RF Section
amplifying the received.

This section down-converts the received RF Mixer /

3)
frequencies to intermediate frequencies (IFs). Converter

This section primary functions are amplification and

4) IF Section
selectivity.

This section demodulates the AM wave and converts

5) AM Detector
it to the original information signal.

This section amplifies the recovered information.

6) Comprises several cascaded audio amplifiers and Audio Section
one or more speakers.

A receiver parameter that is used to measure the

7) ability of the receiver to accept a given band of Selectivity
frequencies and reject all others.

The ratio of the bandwidth 60dB below maximum

8) signal level and bandwidth 3dB below maximum Shape Factor
signal level.

9) The most prevalent form of noise and is directly Thermal Noise

proportional to bandwidth.

10) Noise reduction ratio achieved by reducing the Bandwidth Improvement

Bandwidth.

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The corresponding reduction in the noise figure due

Noise Figure
11) to the reduction in bandwidth expressed
Improvement
mathematically in dB.

The ________ of a receiver is the minimum RF signal

level that can be detected at the input to the
12) receiver and still produce a usable demodulated Sensitivity
information signal.
Also known as receiver threshold.

Defined as the difference in decibels between the

minimum input level necessary to discern a signal
13) Dynamic Range
and the input level that will overdrive the receiver
and produce distortion.

Defined as the output power when the RF amplifier

14) response is 1 dB less than the ideal linear-gain 1-dB Compression Point
response.

A measure of the ability of a communication system

15) to produce, at the output of the receiver, an exact Fidelity
replica of the original source information.

Any frequency, phase, or amplitude variations that

16) are present in the demodulated waveform that were Distortion
not in the original information signal.

The total phase shift encountered by a signal and

17) can generally be tolerated as long as all frequencies Absolute Phase Shift
undergo the same amount of phase delay.

Occurs when different frequencies undergo different

phase shifts and ay have a detrimental effect on a
complex waveform.
18) Differential Phase Shift

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Defined as the ratio of the power transferred to a

Insertion Loss
19) load with a filter in the circuit to the power transferred
( IL )
to a load without the filter.

A hypothetical value that cannot be directly

Equivalent Noise
20) measured. A parameter that is used in low-noise,
Temperature
sophisticated radio receivers rather than noise figure.

The frequencies generated in the receiver and used

Coherent /
21) for demodulation are synchronized to oscillator
Synchronous Receiver
frequencies generated in the transmitter.

Either no frequencies are generated in the receiver or

the frequencies used for demodulation are Noncoherent /
22)
completely independent from the transmitter’s carrier Asynchronous Receiver
frequency.

One of the earliest types of AM receivers and are

23) probably the simplest designed radio receivers Tuned Radio Frequency
available today.

A phenomenon at radio frequencies where current

24) Skin Effect
flow is limited to the outermost area of a conductor.

A technique where TRF receiver’s instability can be

reduced somewhat by tuning each amplifier to a
25) Stagger Tuning
slightly different frequency, slightly above or below
the desired center frequency.

Means to mix two frequencies together in a nonlinear

26) device or to translate one frequency to another using Heterodyne
nonlinear mixing.

A broad –tuned bandpass filter with an adjustable

27) center frequency that is tuned to desired carrier Preselector
frequency.

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The most common intermediate frequency used in

28) 455 kHz
AM broadcast-band receivers is ________.

Consists of a series of IF amplifiers and bandpass filters

29) IF Section
and is often called IF strip.

Refer to frequencies that are used within a transmitter

or receiver that fall somewhere between the radio
30) Intermediate Frequency
frequencies and the original source information
frequencies.

Means that the two adjustments are mechanically

tied together so that a single adjustment will change
31) Gang Tuning
the center frequency of the preselector and, at the
same time, change the local oscillator frequency.

When the local oscillator is tuned above High-side Injection /

32)
the RF it is? High-beat Injection

When the local oscillator is tuned below Low-side Injection /

33)
the RF it is? Low-beat Injection

The side frequencies undergo a sideband reversal

34) Sideband Inversion
during the heterodyning process called?

The ability of the local oscillator in a receiver to

oscillate above or below the selected radio
35) frequency carrier by an amount equal to the Tracking
intermediate frequency throughout the entire radio
frequency band.

The difference between the actual oscillator

frequency and the desired frequency.
36) Tracking Error

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Any frequency other than the selected radio

frequency carrier that, if allowed to enter a receiver
37) and mix with the local oscillator, will produce a cross- Image Frequency
product frequency that is equal to the intermediate
frequency.

A numerical measure of the ability of a preselector to Image-frequency

38)
reject the image frequency. Rejection Ratio

Occurs when a receiver picks up the same station at

39) Double Spotting
two nearby points on the receiver tuning dial.

A high-gain, low-noise, tuned amplifier that, when

40) used, is the first active stage encountered by the RF Amplifier
received signal.

High-performance microwave receivers require a

Low-noise Amplifier
41) ________ as the input stage of the RF section to
( LNA )
optimize their noise figure.

MEsa Semiconductor FET

A FET with a metal-semiconductor junction at the
42) Semiconductor FET
gate of the device, called a Schottky barrier.
( MESFET )

A wideband, unconditionally stable, low-power, dual-

43) gain linear integrated-circuit RF amplifier NE / SA5200
manufactured by Signetics Corporation.

This section purpose is to down-convert the incoming

Mixer /
44) radio frequencies to intermediate frequencies
Converter Stage
proportional to bandwidth.

The difference between the level of the IF output with

an RF input signal to the level of the IF output with an
45) Conversion Gain
IF input signal.

46) Self-excited Mixer

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A configuration where the mixer excites itself by

feeding energy back to the local oscillator tank
circuit to sustain oscillations noise figure.

A low-power VHF monolithic double-balanced mixer

47) with input amplifier, on-board oscillator, and voltage NE / SA602A
regulator.

Are relatively high-gain amplifiers that are very similar

Intermediate Frequency
48) to RF amplifiers, except that IF amplifiers operate over
( IF ) Amplifier
a relatively narrow, fixed frequency band.

The most common technique used for coupling

where the voltage that is applied to the primary Inductive or Transformer
49)
windings of a transformer is transferred to the Coupling
secondary windings.

Ability of a coil to induce a voltage within its

50) Inductance
windings.

51) Ability of one coil to induce a voltage in another coil. Mutual Inductance

52) The ratio of the secondary flux to the primary flux. Coefficient of Coupling

The transfer of flux from the primary to the secondary

53) windings and is directly proportional to the Flux Linkage
coefficient of coupling.

The point where the reflected resistance is equal to

54) the primary resistance an d the Q of the primary tank Critical Coupling
circuit is halved and the bandwidth doubled.

Is caused by the reactive element of the reflected

55) impedance being significant enough to change the Double Peaking
resonant frequency of the primary tuned circuit.

56) Optimum Coupling

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The coefficient of coupling approximately 50%

greater than the critical value yields a good
compromise between flat response and steep skirts.

IF transformers come as specially designed tuned

57) circuits in groundable metal packages IF Cans
called _______.

A differential cascoded amplifier designed for use in

58) communications and industrial equipment as an IF or CA3028A
RF amplifier at frequencies from dc to 120 MHz.

The function of this circuit is to demodulate the AM

59) signal and recover or reproduce the original source AM Detector
information.

A simple noncoherent AM demodulator using a

60) diode. Also called as diode, shape, or envelope Peak Detector
detector.

A distortion in the detection process where the RC

61) time constant is too short, the output waveform Rectifier Distortion
resembles a half-wave rectified signal.

A distortion in the detection process where the RC

time constant is too long, the slope of the output
62) Diagonal Clipping
waveform cannot follow the trailing slope of the
envelope.

A circuit that compensates for minor variations in the Automatic Gain Control
63)
received RF signal. ( AGC )

It prevents the AGC feedback voltage from reaching

64) the RF or IF amplifiers until the RF level exceeds a Delayed AGC
predetermined magnitude.

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Is similar to conventional AGC except that the

receive signal is monitored closer to the front end of
65) Forward AGC
the receiver and the correction voltage is fed
forward to the IF amplifiers.

Its purpose is to quiet a receiver in the absence of a

66) Squelch Circuit
received signal.

Are used to remove sporadic, high-amplitude noise

Limiters /
67) transients of short duration, such as impulse noise in
Clippers
the audio section of a receiver.

A method of measuring signal strength relative to

Signal-to-Notched Noise
68) noise strength where an RF carrier modulated 30% by
Ratio
a 1-kHz tone is applied to the input of the receiver.

A National Semiconductor Corporation linear

integrated circuit AM radio chip that has an onboard
RF amplifier, mixer, local oscillator, and IF amplifier
69) LM1820
stages. An LIC audio amplifier, such as the LM386,
and a speaker are necessary to complete a
functional receiver.

This receivers would need only two external

70) components: a volume control and a station tuning PLL Receivers
control.

The ratio of the demodulated signal level at the

output of the receiver (audio) to the RF signal level at
71) the input to the receiver, or the difference between Net Receiver Gain
the audio signal level in dBm and the RF signal level in
dBm.

Includes all the gains and losses incurred by a signal

as it propagates from the transmitter output stage to
72) System Gain
the output of the detector in the receiver and
includes antenna gain and transmission line and
propagation losses.

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SINGLE – SIDEBAND COMMUNICATIONS

CHAPTER 6 SYSTEMS

# DEFINITIONS TERMS

A form of amplitude modulation in which the carrier is AM Single-sideband Full

1) transmitted at full power but only one of the Carrier
sidebands is transmitted. ( SSBFC )

A form of amplitude modulation in which the carrier is AM Single-sideband

2) totally suppressed and one of the sidebands Suppressed Carrier
removed. ( SSBSC )

A form of amplitude modulation in which one

sideband is totally removed and the carrier voltage is AM Single-sideband
3) reduced to approximately 10% of its unmodulated Reduced Carrier
amplitude. Sometimes called single-sideband ( SSBRC )
reinserted carrier.

It is the reinserted carrier in SSBRC for demodulation

4) Pilot Carrier
purposes.

A form of amplitude modulation in which a single AM Independent

5) carrier frequency is independently modulated by two Sideband
different modulating signals. ( ISB )

A form of amplitude modulation in which the carrier

AM Vestigial Sideband
6) and one complete sideband are transmitted, but
( VSB )
only part of the second sideband is transmitted.

________ is the picture portion of a commercial

7) VSB System
television broadcasting signal.

Are obvious advantages of single-sideband

suppressed- and reduced- carrier transmission over Bandwidth Conservation
8)
conventional double- sideband full-carrier and Power Efficiency
transmission.

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This ratio determines the degree of intelligibility of a

9) Signal-to-Noise Ratio
received signal.

With double-sideband transmission, the two

sidebands and carrier may propagate through the
transmission media by different paths and therefore,
10) Selective Fading
experience different transmission impairments. This
condition is
called ________.

A condition in double-sideband transmission where

11) Sideband Fading
one sideband is significantly attenuated.

A form of selective fading where there is a reduction

of the carrier level of a 100%-modulated wave that
12) Carrier-Amplitude Fading
will make the carrier voltage less than the vector sum
of the two sidebands.

A condition where the relative positions of the carrier

and sideband vectors of the received signal change,
Carrier or Sideband
13) causing a decided change in the shape of the
Phase Shift
envelope, causing a severely distorted demodulated
signal.

A product modulator where the output signal is the

14) AM Modulator
product of the modulating signal and the carrier.

Modulator circuits that inherently remove the carrier

15) DSBSC Modulators
during the modulation process.

A circuit that produces a double-sideband

16) Balanced Modulator
suppressed-carrier signal.

A balanced modulator that is constructed with

17) diodes and transformers. Sometimes called Balanced Ring Modulator
balanced lattice modulator.

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The small carrier component that is always present in

18) Carrier Leak
the output signal of a balanced modulator.

The operation of this balanced modulator as the

balanced ring modulator, is completely dependent
Balanced Bridge
19) on the switching action of diodes D1 through D4
Modulator
under the influence of the carrier and modulating
signal voltages.

A double-balanced modulator/demodulator that

LM1497 / 1596
20) produces an output signal that is proportional to the
Balanced Modulator IC
product of its input signals.

21) The circuit where the carrier is reinserted. Linear Summer

Filter, Phase-Shift, and

22) Three methods for single-sideband generation.
Third Method

Crystal Lattice,
Ceramic,
23) Types of single-sideband filters.
Mechanical,
Saw Filters

A mechanically resonant transducer that receives

electrical energy, converts it to mechanical
24) Mechanical Filter
vibrations, and then converts the vibrations back to
electrical energy at its output.

Filters that use acoustic energy rather than electro-

Surface Acoustic Wave
25) mechanical energy to provide excellent
Filters
performance for precise bandpass filtering.

Reflected energy that cancels and attenuates the

26) Destructive Interference
incident wave energy.

27) Reflected energy that aids the incident wave energy. Constructive Interference

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A transducer which launches the acoustic wave in

28) Unidirectional Transducer
only one direction.

Any difference between the transmit and receive

29) local oscillator frequencies produces a _______ in the frequency offset error
demodulated information signal.

Fifty hertz or more offset is distinguishable by a normal

30) tonal variation
listener as a _______.

A narrowband PLL that tracks the pilot carrier in the

composite SSBRC receiver signal and uses the
31) Carrier Recovery Circuit
recovered carrier to generate coherent local
oscillator frequencies in the synthesizer.

An SSB receiver that uses a PLL carrier recovery circuit

32) and a frequency synthesizer to produce coherent Multichannel Pilto Carrier
local and beat frequency oscillator frequencies.

Systems that provide narrowband voice Amplitude-

communications for land-mobile services with nearly Compandoring
33)
the quality achieved with FM systems and do it using Single-Sideband
less than one-third the bandwidth. ( ACSSB )

The process of combining transmissions from more

than one source and transmitting them over a
34) Multiplexing
common facility, such as metallic or optical fiber
cable or a radio-frequency channel.

A transmission that can be used to combine

hundreds or even thousands of narrowband channels Single-Sideband
35) into single, composite wideband channel without the Suppressed-Carrier
channels interfering with each other. Transmission

Peak Envelope Power

Single-sideband transmitters are rated in ________ and
36) ( PEP ) &
________.
Peak Envelope Voltage
( PEV )

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CHAPTER 7 ANGLE MODULATION TRANSMISSION

# DEFINITIONS TERMS

1) Two forms of angle modulation. FM and PM

Angle modulation was first introduced in the year

2) 1931
________ as an alternative to amplitude modulation.

He developed the first successful FM radio system in

1936, and in July 1939, the first regularly scheduled
3) broad-casting of FM signals began in Alphine, New Major E. H. Armstrong
Jersey. Also developed the superheterodyne
receiver.

A modulation that results whenever the phase angle

4) Angle Modulation
() of a sinusoidal wave is varied with respect to time.

Varying the frequency of a constant-amplitude

Direct Frequency
carrier directly proportional to the amplitude of the
5) Modulation
modulating signal at a rate equal to the frequency of
( FM )
the modulating signal.

Varying the phase of a constant-amplitude carrier

directly proportional to the amplitude of the Direct Phase Modulation
6)
modulating signal at a rate equal to the frequency of ( PM )
the modulating signal.

The relative angular displacement (shift) of the carrier Phase Deviation

7)
phase in radians in respect to the reference phase. ( )

The relative displacement of the carrier frequency in Frequency Deviation

8)
hertz in respect to its unmodulated value. (F )

9) The original unmodulated carrier frequency in the Carrier Rests Frequency

resultant angle-modulated waveform.

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The instantaneous change in the phase of the carrier

at a given instant of time and indicates how much Instantaneous Phase
10)
the phase of the carrier is changing with respect to its Deviation
reference phase.

The precise phase of the carrier at a given instant of

11) Instantaneous Phase
time.

The instantaneous change in frequency of the carrier

Instantaneous Frequency
12) and is defined as the first time derivative of the
Deviation
instantaneous phase deviation.

The precise frequency of the carrier at a given instant

13) of time and is defined as the first time derivative of Instantaneous Frequency
the instantaneous phase.

Are the output–versus-input transfer functions for the

modulators, which give the relationship between
14) Deviation Sensitivities
what output parameter changes in respect to
specified changes in the input signal.

Is called the modulation index or sometimes index of

15) Peak Phase Modulation
modulation.

The change in frequency that occurs in the carrier

16) when it is acted on by a modulating-signal Frequency Deviation
frequency.

17) The peak-to-peak frequency deviation (2f). Carrier Swing

The ratio of the frequency deviation actually

produced to the maximum frequency deviation
allowed by law stated in percent form.
18) Percent Modulation

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A circuit in which the carrier is varied in such a way

19) that its instantaneous phase is proportional to the Phase Modulator
modulating signal.

A circuit which the carrier is varied in such a way that

20) its instantaneous phase is proportional to the integral Frequency Modulator
of the modulating signal.

________ of the first kind for several values of

21) modulation index provides the number of side Bessel Function
frequency pairs and their corresponding magnitude.

A side frequency is not considered significant unless it

22) has an amplitude equal to or greater than ____ of the 1%
unmodulated carrier amplitude.

23) The modulation index is less than 1. Low-index Case

24) The modulation index is greater than 10. High-index Case

25) Modulation indices greater than 1 and less than 10. Medium Index

26) Low-index FM systems are sometimes called? Narrowband FM

A rule which is an approximation and gives

transmission bandwidths that are slightly narrower
27) than the bandwidths. It defines a bandwidth that Carson’s Rule
includes approximately 98% of the total power in the
modulated wave.

The worst-case modulation index and is equal to the

maximum peak frequency deviation divided by the
Deviation Ratio
28) maximum modulating-signal frequency.
( DR )

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The FCC has assigned the commercial FM broadcast

29) service a _______ band of frequencies that extends 20 MHz
from 88 MHz to 108 MHZ.

The 20–MHz band is divided into 100, ________ wide

30) 200 kHz
channels beginning at 88.1 MHz.

To provide high-quality, reliable music, the maximum

frequency deviation allowed is _______ with a 75 kHz ;
31)
maximum modulating-signal frequency 15 kHz
of _______.

The highest side frequencies from one channel are

Adjacent Channel
32) allowed to spill over into adjacent channels,
Interference
producing an interference known as _______.

A _______ wide guard band is usually on either side of

33) 200 kHz
each assigned channel.

The noise voltage at the output of an FM

34) demodulator increases linearly with frequency. This is FM Noise Triangle
called ______.

The high-frequency modulating signals are

35) emphasized or boosted in amplitude in the Pre-emphasis
transmitter prior to performing modulation.

The reciprocal of pre-emphasis that restores the

36) original amplitude-versus-frequency characteristics to De-emphasis
the information signals.

A circuit that provides a constant increase in the

amplitude of the modulating signal with an increase
37) in frequency. Pre-emphasis Network

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When the frequency of the carrier is modulated by Direct FM

38)
the information signal, _______ results. ( Indirect PM )

When the phase of the carrier is modulated by the Direct PM

39)
information signal, _______ results. ( Indirect FM )

Angle modulation in which the frequency of the

40) Direct FM
carrier is varied directly by the modulating signal.

Varactor Diode,
Three common methods for producing direct
41) FM Reactance,
frequency modulation.
Linear IC Modulations

Direct frequency modulator used for low-index Varactor Diode Direct FM

42)
Applications, such as two-way mobile radio. Modulator

A direct FM modulator using a JFET as the active

43) FM Reactance Modulator
device.

A complete FM modulator on a single 8-pin DIP

44) MC1376
integrated circuit chip.

Can generate a direct FM output waveform that is

Linear IC VCO and
45) relatively stable, accurate, and directly proportional
Function Generators
to the input modulating signal.

Angle modulation in which the frequency of the

46) Direct PM
carrier is deviated indirectly by the modulating signal.

Varactor Diode and

Two common methods for producing direct phase
47) Transistor Direct PM
modulation.
Modulator

The process of up-converting the frequency of the

48) modulated carrier after modulation has been Frequency Up-Conversion
performed.

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Two basic methods of performing frequency up- Heterodyning and

49)
conversion. Frequency Multiplication

An up-conversion method where a low-frequency

modulated carrier can either be up- or down-
50) Heterodyne Method
converted to a different location in the frequency
spectrum without changing its modulation properties.

An up-conversion method where the modulation

51) properties of a carrier can be increased at the same Multiplication Method
time that the carrier frequency is up-converted.

Transmitters that produce an output waveform in

52) which the frequency deviation is directly proportional Direct FM Transmitters
to the modulating signal.

A circuit that compares the frequency of he non

crystal carrier oscillator to a crystal reference Automatic Frequency
53) oscillator and then produces a correction voltage Control
proportional to the difference between the ( AFC )
frequencies.

A frequency-selective device whose output voltage

54) is proportional to the difference between the input Frequency Discriminator
frequency and its resonant frequency.

A voltage added to the modulating signal to

55) automatically adjust the master oscillator’s center dc Correction Voltage
frequency to compensate for the low-frequency drift.

A ________ preceded by a differentiator generates a

56) FM Modulator
PM waveform.

Transmitters that produce an output waveform in

57) which phase deviation is directly proportional to the Indirect FM Transmitters
modulating signal.

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Probably the most significant advantage of angle

58) modulation transmission over amplitude modulation Noise Immunity
transmission.

Allows a receiver to differentiate between two signals

59) Capture Effect
received with the same frequency.

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ANGLE MODULATION RECEPTION

CHAPTER 8 AND FM STEREO

# DEFINITIONS TERMS

In this receivers, the voltage at the output of the

1) audio detector is directly proportional to the FM Receivers
frequency deviation at its input.

In this receivers, the voltage at the output of the

2) audio detector is directly proportional to the phase PM Receivers
deviation at its input.

The circuits used to demodulate FM and PM signals

3) are both described under the FM Receivers
heading ________ .

A modulation where the information is impressed

4) onto the carrier in the form of frequency or phase Angle Modulation
variations.

A method used to remove amplitude variations

caused by noise from the composite waveform
5) Limiting
simply by clipping the peaks of the envelop prior to
detection.

The section that rejects the image frequency in FM

6) Pre-selector
receivers.

The section that establishes the signal-to-noise ratio

7) RF Amplifier
and noise figure in FM receivers.

8) The section that down-converts RF to IF. Mixer / Converter

The section that provide most of the gain and

9) IF Amplifiers
selectivity.

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The section that removes the information from the

10) Detector
modulated wave.

Limiter,
The envelope (peak) detector common to AM
Frequency Discriminator
11) receivers is replaced in FM receivers by a ________,
and
________, and ________.
De-emphasis Network

The circuit that extracts the information from the

12) Frequency Discriminator
modulated wave.

Are frequency-dependent circuits designed to

13) produce an output voltage that is proportional to the FM Demodulators
instantaneous frequency at its input.

Slope Detector,
Foster-Seely Discriminator,
Ratio Detector,
14) Circuits used for demodulating FM signals.
PLL Demodulator,
and
Quadrature Detector

Circuits that convert FM to AM and then

Tuned-Circuit Frequency
15) demodulate the AM envelope with conventional
Discriminators
peak detectors.

A tuned-circuit frequency discriminator that has

16) the most nonlinear voltage-versus-frequency Slope Detector
characteristics and, therefore, is seldom used.

Is simply two single-ended slope detectors

17) Balanced Slope Detector
connected in parallel and fed 180 out of phase.

Sometimes called a phase shift discriminator that

Foster-Seeley
18) is a tuned-circuit frequency discriminator whose
Discriminator
operation is very similar to that of a balanced
slope detector.

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The typical voltage-versus-frequency response

19) S-curve
curve for a Foster-Seeley discriminator.

An FM demodulator that is relatively immune to

20) Ratio Detector
amplitude variations in its input signal.

This FM demodulator requires no tuned circuits

and automatically compensates for changes in
21) PLL FM Demodulator
the carrier frequency due to instability in the
transmit oscillator.

Sometimes called a coincidence detector that

extracts the original information signal from the Quadrature FM
22)
composite IF waveform by multiplying two Demodulator
quadrature (90 out of phase) signals.

Special circuits that removes the unwanted

23) amplitude variations since with FM, the Limiters
information is contained in frequency variations.

The limiter circuit produces a constant-amplitude

Threshold,
output for all input signals above a prescribed
24) Quieting, or
minimum input level, which is often
Capture Level
called the ________.

The improvement in the S/N ratio when the

FM Thresholding, FM
peaks of the signal have the limiter so far into
25) Quieting, or
saturation that the weaker noise is totally FM Capture Effect
eliminated.

The inherent ability of FM to diminish the effects

of interfering signals. Also, the ability to
26) differentiate between two signals received at Capture Effect
the same frequency.

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Is the minimum dB difference in signal strength

Capture Ratio of an FM
27) between two received signals necessary for the
Receiver
capture effect to suppress the weaker signal.

An improved monolithic low-power FM IF system

manufactured by Signetics Corporation. It is a
28) high gain, high frequency device that offers low- NE/SA614A
power consumption and excellent input
sensitivity at 455 kHz.

A multiplier cell similar to a mixer stage, but

instead of mixing two different frequencies, it
29) Quadrature Detector
mixes two signals with the same frequencies but
with different phases.

A low-voltage, high-performance monolithic FM

30) IF system similar to the NE/SA614A except with NE/SA616
the addition of a mixer/oscillator circuit.

A monolithic integrated-circuit FM radio system

manufactured by Signetics Corporation for
31) TDA7000
monolithic FM portable radios. A complete FM
radio receiver on a single integrated-circuit chip.

A circuit that is used to reduce the total

32) harmonic distortion (THD) by compressing the IF Frequency-Locked-Loop
frequency swing (deviation).

With this transmission, the information signal is

33) Stereophonic Transmission
spatially divided into two 50-Hz to 15-kHz audio
channels (a left and a right).

Used to broadcast uninterrupted music to Subsidiary

private subscribers, such as department stores, Communications
34)
restaurants, and medical offices equipped with Authorization
special receivers; Sometimes cordially refer to as ( SCA )
“elevator music”
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The process of placing two or more independent

channels next to each other in the frequency Frequency Division
35) domain (stacking the channels), and then Multiplexing
modulating a single high-frequency carrier with ( FDM )
the combined signal.

The primary audio channel remained at 50 Hz to 60 kHz

36) 15 kHz, while an additional SCA channel is To
frequency translated to the _______ passband. 74 kHz

The SCA subcarrier may be AM single- or double-

37) sideband transmission or FM with a maximum 7 kHz
modulating-signal frequency of _______.

The frequency of the pilot carrier of FM stereo

38) 19 kHz
transmission.

When the phase of the carrier is modulated by Direct PM

39)
the information signal, _______ results. ( Indirect FM )

A monolithic FM stereo demodulator that uses

40) PLL techniques to derive the right and left audio XR-1310
channels from the composite stereo signal.

Half-duplex, one-to-many radio communications

41) Two-Way Mobile Radio
with no dial tone.

Provides 26.96 to 27.41 MHz public, non-

commercial radio service for either personal or Class D Citizens Band
42)
business use utilizing push-to-talk AM DSBFC and ( CB ) Radio
AM SSBFC.

Cover a broad-frequency band from 1.8 MHz to

43) Amateur ( HAM ) Radio
above 300 MHz. Designed for personal use
without pecuniary interest.
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Provides 2.8 MHz to 457 MHz. ABS disseminates

Aeronautical
information for the purposes of air navigation
Broadcasting
44) and air-to-ground communications utilizing Service
conventional AM and various forms of AM SSB in ( ABS )
the HF, MF, and VHF frequency bands.

Full-duplex, on-to-one radio telephone

45) Mobile Telephone Service
communications.

Provides worldwide telecommunication service

Personal
using handheld telephones that communicate
Communications Satellite
46) with each other through low earth-orbit satellite
Service
repeaters incorporating QPSK modulation and ( PCSS )
both FDMA and TDMA.

Is used extensively for public safety mobile

Two-Way FM Radio
47) communications, such as police and fire
Communications
departments and emergency medical services.

The maximum frequency deviation for two-way

FM transmitters is typically ________, and the 5 kHz ;
48)
maximum modulating-signal frequency 3 kHz
is ________.

Transmissions are initiated by closing a ________

Push-To-Talk
49) switch, which turns on the transmitter and shuts
( PTT )
off the receiver.

It was used as early as 1921 when the Detroit

50) Mobile Radio
Police Department used a mobile radio system
that operated at a frequency close to 2 MHz.

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It was used rather than a simple mechanical

Electronic
51) switch to reduce the static noise associated with
Push-To-Talk
contact bounce in mechanical switches.

Transmitters equipped with ________ are

Voice-Operated
automatically keyed each time the operator
52) Transmitter
speaks into the microphone, regardless of ( VOX )
whether the PTT button is depressed.

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CHAPTER 9 DIGITAL MODULATION

# DEFINITIONS TERMS

Is the transmission, reception, and processing of Electronic

1)
information with the use of electronic circuits. Communication

Is defined as knowledge or intelligence that is

2) Information
communicated between two or more points.

Is the transmittal of digitally modulated analog signals

3) (carriers) between two or more points in a Digital Modulation
communication system.

4) System involving the transmission of digital pulses. Digital Transmission

The information signal is digital and the amplitude (V)

Amplitude Shift Keying
5) of the carrier is varied proportional to the information
( ASK )
signal.

The information signal is digital and the frequency (f)

Frequency Shift Keying
6) of the carrier is varied proportional to the information
( FSK )
signal.

The information signal is digital and the phase (θ) of

Phase Shift Keying
7) the carrier is varied proportional to the information
( PSK )
signal.

A modulation where both the amplitude and the Quadrature Amplitude

8) phase are varied proportional to the information Modulation
signal. ( QAM )

Performs level conversion and then codes the

9) incoming data into groups of bits that modulate an Pre-coder
analog carrier.

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Is a highly theoretical study of the efficient use of

10) bandwidth to propagate information through Information Theory
electronic communications systems.

Is a measure of how much information can be

11) propagated through a communications system and Information Capacity
is a function of bandwidth and transmission time.

The most basic digital symbol used to represent Binary Digit /

12)
information. Bit

In 1928, _________ of Bell Telephone Laboratories

13) developed a useful relationship among bandwidth, R. Hartley
transmission time, and information capacity.

In 1948, mathematician _________ (also of Bell

Telephone Laboratories) published a paper in the Bell
14) System Technical Journal relating the information Claude E. Shannon
capacity of a communications channel to
bandwidth and signal-to-noise ratio.

Simply represents a digit that corresponds to the

15) number of conditions, levels, or combinations possible M
for a given number of binary variables.

Refers to the rate of change of a digital information

16) Bit Rate
signal, which is usually binary.

Refers to the rate of change of a signal on a

17) transmission medium after encoding and modulation Baud
have occurred.

Sometimes called a symbol and could be encoded

as a change in the amplitude, frequency, or phase.
18) Signaling Element

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The minimum theoretical bandwidth necessary to

19) Nyquist Bandwidth
propagate a signal.

According to ________, binary digital signals can be

propagated through an ideal noiseless transmission
20) H. Nyquist
medium at a rate equal to two time the bandwidth
of the medium.

The carrier is either “on” or “off” which is why

21) amplitude- shift keying is sometimes On-Off Keying
referred to as ________.

22) A logic 1 frequency (fm) for FSK. Mark

23) A logic 0 frequency (fs) for FSK. Space

The mark and space frequencies are separated

Peak Frequency
from the The mark and space frequencies are
24) Deviation
separated from thecarrier frequency
(f)
by the _________ and from each of by 2 f.

_______ is the peak frequency deviation of the carrier

and is equal to the difference between the
25) f
carrier rest frequency and either the mark or
space frequency.

A type of FSK detection wherein there is no frequency

involved in the demodulation process that is
26) Noncoherent Detection
synchronized either in phase, frequency, or both with
the incoming FSK signal.

A type of FSK detection wherein the incoming FSK

signal is multiplied by a recovered carrier signal
27) that has exact same frequency and phase as Coherent Detection
the transmitter reference.

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Is binary FSK except the mark and space frequencies Continuous-Phase FSK
28)
are synchronized with the input binary bit rate. ( CP-FSK )

A signal state-space diagram, is similar to a phasor

29) diagram except that the entire phasor is not drawn. Constellation Diagram
Only the relative positions of the peaks of the phasors
are shown.

Is a product modulator; the output signal is the

30) Balanced Modulator
product of the two input signals.

Detect and regenerates a carrier signal that is both

Coherent Carrier
31) frequency and phase coherent with the original
Recovery Circuit
transmit carrier.

Also known as quadrature PSK that is another form of

Quaternary PSK
32) angle-modulated, constant-amplitude digital
( QPSK )
modulation.

33) A group of two bits. Dibit

It modulates the carrier that is in phase with the

34) I Bit
reference oscillator.

It modulates the carrier that is 90 out of phase or in

35) Q Bit
quadrature with reference carrier.

36) Is two BPSK modulators combined in parallel. QPSK Modulator

The highest fundamental frequency present at

the data input to the I or the Q balanced modulator
37) is equal to _______ of the input data rate. ¼

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The fastest output rate of change (baud) is also

38) ½
equal to ________ of the input bit rate.

The outputs of the product detectors are fed to the

________, where they are converted from parallel I
39) Bit Combining Circuit
and Q data channels to a single binary output
data stream.

Is a modified for of QPSK where the bit waveforms on

Offset QPSK
40) the I and Q channels are offset or shifted in phase
( OQPSK )
from each other by one-half of a bit time.

41) The advantage of OQPSK is the _________ that must Limited Phase Shift
be imparted during modulation.

With ________, three bits are encoded, forming tribits

42) 8 PSK
and producing eight different output phases.

43) Group of 3 bits. Tribit

Also known as maximum distance code used to

44) Gray Code
reduce the number of transmission errors.

Converts the I/C and Q/C bit pairs to serial, Q, and C Parallel-to-Serial
45)
output data streams. Logic Circuit

46) Group of 4 bits. Quadbits

16-PSK can undergo only a _______ phase shift during

47) 11.25
transmission and still retain its integrity.

Is an M-ary encoding technique where M=8. The

output signal from this modulator is not a constant-
48) 8 – QAM
amplitude signal

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The process of introducing transitions (pulses) into the

49) Scrambling
binary signal using a prescribed algorithm.

It uses the same algorithm for scrambling to remove

50) Descrambler
the transitions.

Is an alternative form of digital modulation where the

Differential Phase-Shift
binary input is contained in the difference between
51) Keying
two successive signalling elements rather than the
( DPSK )
absolute phase.

Data transmission rates in excess of 56 kbps can be

Trellis Code Modulation
52) achieved, over standard telephone circuits using an
( TCM )
encoding technique called ________.

__________ at IBM Zuerich Research Laboratory

developed TCM, which involves using convolutional
53) (tree codes, which combines encoding and Dr. Ungerboeck
modulation to reduce the probability of error, thus
improving the bit error performance.

Defines the manner in which signal-state transitions

are allowed to occur, and transitions that do not
54) Trellis Coding
follow this pattern are interpreted in the receiver as
transmission errors.

The distance between symbols on the constellation

55) Euclidean Distance
of the TCM coding scheme on standard QAM.

Is the ratio of the average carrier power (the

Carrier-To-Noise
56) combined power of the carrier and its associated
Power Ratio
sidebands) to the thermal noise power.

Is simply the energy of a single bit of information.

57) Energy Per Bit

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The phase relationship between signalling elements

58) for BPSK (i.e., 180 out of phase) is the optimum Antipodal Signaling
signalling format, referred to as ________.

Noncoherent
( Asynchronous )
59) Two types of FSK systems. And
Coherant
( Synchonous )

The transmitter and receiver are not frequency or

60) Noncoherent FSK
phase synchronized.

Local receiver reference signals are in frequency and

61) Coherent FSK
phase lock with the transmitted signals.

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CHAPTER 10 DIGITAL TRANSMISSION

# DEFINITIONS TERMS

Is the transmittal of digital signals between two or

1) Digital Transmission
more points in a communications system.

_________ developed the first digital transmission

system for the purpose of carrying digitally encoded
2) AT&T
analog signals, such as human voice, over metallic
wire cables between telephone offices.

The primary advantage of digital transmission over

3) Noise Immunity
analog transmission.

Digital signals are also better suited than analog

4) signals for processing and combining using a Multiplexing
technique called _____.

Is the processing of analog signals using digital

Digital Signal Processing
5) methods and includes bandlimiting the signal with
( DSP )
filters, amplitude equalization, and phase shifting.

Digital transmission systems are more resistant to

6) analog systems to additive noise because they Signal Regeneration
use ________ rather than signal amplification.

Consist essentially of sampling analog information

signals and then converting those samples into
7) discrete pulses and transporting the pulses from Pulse Modulation
a source to a destination over a physical
transmission medium.

PWM, PPM, PAM

The four predominant methods of pulse modulation.
8) And
PCM

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Sometimes called pulse duration modulation (PDM) or pulse

length modulation (PLM), as the width (active portion
Pulse Width Modulation
9) of the duty cycle) of a constant amplitude pulse is
( PWM )
varied proportional to the amplitude of the
analog signal at the time the signal is sampled.

The position of a constant-width pulse within a

Pulse Position Modulation
10) prescribed time slot is varied according to the
( PPM )
amplitude of the sample of the analog signal.

The amplitude of a constant-width, constant-position

Pulse Amplitude
11) pulse is varied according to the amplitude of the
Modulation
sample of the analog signal.

The analog signal is sampled and then converted to Pulse Code Modulation
12)
a serial n-bit binary code for transmission. ( PCM )

__________ is credited with inventing PCM in 1937

13) Alex H. Reeves
while working for AT&T at its Paris laboratories.

A circuit that periodically samples the analog input

Sample-and-Hold
14) signal and converts those samples to a multilevel
Circuit
PAM signal.

The transmission line ________ are placed at

15) Repeaters
prescribed distances to regenerate the digital pulses.

An integrated circuit that performs the PCM Codec

16)
encoding and decoding functions. ( Coder / Decoder )

The function of a _________ in a PCM transmitter is to

periodically sample the continually changing analog
input voltage and convert those samples to a series
17) Sampling Circuit
of constant-amplitude pulses that can more easily be
converted to binary PCM code.

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The sampling process alters the frequency spectrum

18) Aperture Error
and introduces an error called _________.

The ________ of the capacitor is called the A/D

19) conversion time because it is during this time that the Storage Time
ADC converts the sample voltage to a PCM code.

If the input to the ADC is changing while it is

20) Aperture Distortion
performing the conversion, _______ results.

_________ theorem establishes the minimum sampling

21) Nyquist Sampling
rate (fs) that can be used for a given PCM system.

The binary codes used for PCM are _________,

22) N-Bit Codes
where n may be any positive integer greater than 1.

Most Significant Bit

23) The sign bit in a sign-magnitude code.
( MSB )

Is the process of converting an infinite number of

possibilities to a finite number of conditions.
24) Quantization
Is the process of rounding off the amplitudes of
flat-top samples to a manageable number of levels.

A type of code where the codes on the bottom half

25) of the table are a mirror image of the codes on the Folded Binary Code
top half, except for the sign bit.

Quantization
26) The magnitude difference between adjacent steps.
Interval or Quantum

If the magnitude of the sample exceeds the highest

quantization interval, ________ (also called peak
limiting) occurs.
27) Overload Distortion

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Quantization Eror
Any round-off errors in the transmitted signal are
(Qe )
28) reproduced when the code is converted back to
Quantization Noise
analog in the receiver.
(Qn)

Is the ratio of the largest possible magnitude to the

smallest possible magnitude (other than 0V) that
29) Dynamic Ratio
can be decoded by the digital-to-analog converter
in the receiver.

During times when there is no analog input signal, the

only input to the PAM sampler is random, thermal
30) Idle Channel Noise
noise also called as __________, that is converted to a
PAM sample just as if it were a signa.

A way to reduce idle channel noise wherein the first

Midtread
31) quantization interval is made larger in amplitude than
Quantization
the rest of the steps.

33) Is the process of compressing and then expanding. Companding

-Law and A-law

34) Two methods of companding:
Companding

Involves compression in the transmitter after the input

sample has been converted to a linear PCM code
35) Digital Companding
and then expansion in the receiver prior to
PCM decoding.

When digitizing speech signals only, special voice

36) Vacoders
encoders/decoders called _______ are often used

A _________ coder extracts the most significant

portions of speech information directly from the time
waveform rather than from the frequency spectrum
37) Linear Predictive
as with the channel and formant vocoders.

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_________ modulation uses a single-bit PCM code to

38) Delta
.chieve digital transmission of analog signals

Two problems associated with delta modulation that Slope Overload and
39)
do not occur with conventional PCM. Granular Sudivision

With ________, the difference in the amplitude of two

Differential PCM
40) successive samples is transmitted rather than the
( DPCM )
actual sample.

41) The secondary lobes are called __________. Ringing test

_________ causes crosstalk between channels

Inter symbol interference
42) that occupy adjacent time slots in a time-division-
( ISI )
multiplexed carrier system.

Special filters called _________ are inserted in the

transmission path to “equalize” the distortion for al
43) Equalizers
frequencies, creating uniform transmission medium
reducing transmission impairments.

A ________ is simply the superposition of a series of

44) Pulse Modulation
harmonically related sine waves with specific
amplitude and phase relationships.

The decision levels for the regenerator are

45) Crosshairs
represented by

The _______ has an effect on the symbol timing

(clock) recovery circuit and, if excessive, may
46) Jitter
significantly degrade the performance of cascaded
regenerative sections.

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CHAPTER 11 DIGITAL T-CARRIERS AND MULTIPLEXING

# DEFINITIONS TERMS

Transmission of information from one or more source

1) To one or more destination over the same Multiplexing
transmission medium (facility).

Unsophisticated form of multiplexing that simply

constitutes propagating signals from different sources Space-Division
2)
of different cables that are contained within the Multiplexing
same trench.

3) Considered as transmission medium. Trench

Form of phase-division multiplexing (PDM) where to

4) date channels (the I and Q) modulate the same QPSK
carrier frequency that has been shifted 90◦ in phase.

5) Modulates a sine wave carrier. I – Channel Bits

6) Modulates a cosine wave carrier. Q – Channel Bits

Time-Division
Multiplexing;
Three most predominant methods of multiplexing Frequency-Division
7)
signals. Multiplexing;
Wavelength-Division
Multiplexing

Transmissions from multiple sources occur on the

8) Time-Division Multiplexing
same but not on the same time.

Most prevalent encoding technique used for TDM

9) PCM
digital signals.

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Use an 8-kHz sample rate and an eight-bit PCM

10) DS-O Channel
code, which produces a 64 kbps PCM line speed.

Simply an electronically controlled digital switch with

11) Multiplexer
two inputs and one outputs.

12) One eight-bit PCM code from each channel TDM Frame
(16 total bits).

13) Time it takes to transmit one TDM frame. Frame Time

A communications system that uses digital pulses

14) Digital Carrier System
rather than analog signals to encode information.

Specifies a digital carrier system using PCM encoded

15) TI or Transmission One
analog signals.

16) Voice band channel bandwidth. 300 Hz to 3000 Hz

17) Special conditioned cables. TI Lines

Used to maintain frame and sample synchronization

18) Framing Bit
between TDM transmitter & receiver.

PCM encoders & decoders with a seven-bit

19) Digital Channel Banks
magnitude.

Supervision between telephone offices, such as on

20) Signaling
hook, off hook, dial pulsing, and so forth.

21) Only seven-bit resolution. Signaling Frame

Extended Super Frame

22)
Consist of 24 193 bit frames, totaling 4632 bits, of Format
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which 24 are framing bits.

CRC-6
23) Used for an error detection code. ( Cyclic Redundancy
Checking )

24) Signaling bit in frame 6. A Bit

25) Signaling bit in frame 12. B Bit

26) Signaling bit in frame 18. C Bit

27) Signaling bit in frame 24. D Bit

Digital interface that provides the physical Data Service Unit /

28)
connection to a digital carrier network. Channel Service Unit

Upgrade from one level in the hierarchy to the next Multiplexers /

29)
higher level. Demultiplexers

Provides a convenient place to make patchable

30) inter connects and perform routine maintenance & Digital Cross Connect
trouble shooting.

Provides frequency shifting for the master group

31) Signal Processor
signals.

Low quality video transmission for use between non-

32) Picturephone
dedicated subscribers.

Identify when transitions occur in the data and

33) Three-Bit Code
whether that transition is from a 1 to a 0 or vice versa.

34) First bit of the code. Address Bit

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35) Converting standard logic levels. Digital Line Encoding

Involves the transmission of only a single nonzero

36) Unipolar
voltage level.

Two nonzero voltages are involved ( a positive

37) voltage for a logic 1 and an equal-magnitude Bipolar
negative voltage for a logic 0 or vice versa).

38) Categorize the type of transmission. Duty Cycle

39) Maintained the entire bit time. Nonreturn to Zero

40) Less than 100% of the bit time. Return to Zero

Produces a condition in which a receive may lose its

41) amplitude reference for optimum discrimination DC Wandering
between received 1’s & o’s.

Popular type of line encoding that produces a strong

42) timing component for clock recovery and does not Digital Biphase
cause dc wandering.

Uses one cycle of a square wave at 0◦ phase to

43) represent a logic 1 and one cycle of a square wave Biphase
at 180◦ phase to represent a logic 0.

Used for encoding SMPTE(Society of Motion Picture

44) and Tele vision Engineers) time-code data for Biphase M
recording on videotapes.

Commonly called the Manchester Code and

45) specified in IEEE standard 802.3 for Ethernet local Biphase L
area networks.

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Forms of delay-modulated codes where a logic 1

condition produces a transition in the middle of the
46) clock pulse, and a logic 0 produces no transition at Miller Codes
the end of the clock intervals unless followed by
another logic 0.

Used for the transmission of PCM-encoded time-

47) T Carriers
division multiplexed digital signals.

Filters and shapes the incoming digital signal and

Amplifier /
48) raise its power level so that the regenerator circuit
Equalizer
can make a pulse-no pulse decision.

Recovery circuit reproduces the cocking information

from the received data and provides the proper
49) timing information to the regenerator so that samples Timing Clock
can be made at the optimum time, minimizing the
chance of an error occurring.

A threshold detector that compares the sampled

50) voltage received to a reference level and Regenerative Repeater
determines whether the bit is a logic 1 or a logic 0.

51) Different version of T carriers used in Europe. E-Lines

Used for frame alignment pattern and for an alarm

52) Time Slot 0
channel.

Added-Digit Framing
Robbed-digit framing
53) Digital carrier frame synchronization. Added-channel framing
Statistical framing
Unique-line code framing

Methods of Interleaving PCM transmissions: Bit Interleaving

54)
Word Interleaving

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Used more often for the transmission of data when

Statistical Time-Division
55) they are called asynchronous TDM, intelligent TDM, or
Multiplexing
simply stat muxs.

Large-scale integration (LSI) chip designed for use in

56) the telecommunications industry for private branch CODEC
exchanges.

Analog Sampling;
57) Three functions of codec. Encoding / Decoding;
Digital Companding

Used to gate the PCM word onto the PCM highway

58) Time Slot Strobe Buffer
when an external buffer is used to drive the line.

Data are input and output for a single channel in a

59) Burst Mode
short burst.

Allows for a flexible data input and output clock Variable-Data-Rate

60)
frequency. Mode

Data from the PCM highway are clock into the

61) codec on the next eight consecutive negative Shift Register Mode
transitions of DCLKR.

Multiple sources that originally occupied the same

Frequency Division
62) frequency spectrum are each converted to a
Multiplexing
different frequency.

Process is accomplished without synchronization

63) Stacking
between stations.

Short Haul;
64) AT&T’s communications network is subdivided into 2:
Long Haul

65) Message Channel

Basic building block of the FDM Heirarchy.

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Separate signals with different wavelengths in a

Demultiplexers /
66) manner similar to the way filters separate electrical
Splitters
signals of different frequencies.

Similar to regular multiplexers and demultiplexers Add / Drop

67) except they are located at intermediate points in the Multiplexers /
system. Demultiplexers

Direct signals of a particular wavelength to a specific

68) destination while not separating all the wavelengths WDM Routers
present on the cable.

Enable more efficient utilization of the transmission

69) capabilities of optical fibers by permitting different WDM Couplers
wavelengths to be combined and separated.

Diffraction Grating ;
70) Three basic types of WDM couplers: Prism ;
Dichroic Filter

Multiplexing system similar to conventional time Synchronous Optical

71)
division multiplexing. Network

72) Has a 51.84-Mbps synchronous frame structure. STS-1

73) Second level of SONET multiplexing. OC-48

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CHAPTER 12 METALLIC CABLE TRANSMISSION MEDIA

# DEFINITIONS TERMS

Provides a conduit in which electromagnetic signals Guided Transmission

1)
are contained. Media

Unguided Transmission
2) Emitted then radiated through air or a vacuum.
Media

Used to propagate electromagnetic signals between Cable Transmission

3)
two locations in a communications system. Medium

Most common means of interconnecting devices in Cable Transmission

4)
local area networks. Systems

Metallic conductor system used to transfer electrical

5) energy from one point to another using electrical Transmission line
current flow.

longitudinal and
6) Two basic kinds of waves.
transverse

7) The rate at which the periodic wave repeats. Frequency

Currents that flow in opposite directions in a

8) Metallic circuit currents
balanced wire pair.

9) Currents that flow in the same direction. Longitudinal currents

10) Cancellation of common mode signals. Common mode rejection

One wire is at the ground potential, whereas the Single-ended or

11)
other is at signal potential. unbalanced

A circuit device used to connect a balanced

12) transmission line to an unbalanced load. balun

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Most common metallic cables used to interconnect Parallel-conductor

14) data communications systems and computer transmission lines and
networks. coaxial transmission lines.

Formed by twisting two insulated conductors around

15) Twisted-pair
each other.

Unshielded twisted pair

16) Types of twisted pair.
and Shielded twisted pair

Coupling that takes place when a transmitted signal

17) is coupled into the received signal at the same end Near-end crosstalk
of the cable.

Pair 1: blue/white stripe

and blue
Pair 2: orange/white
Standard color code specified by the EIA for CAT-5 stripe and orange
18)
cable. Pair 3: green/white strip[e
and green
Pair 4: brown/white stripe
and brown

19) Woven into a mesh. Braid

Name given to the area between the ceiling and the

root in a single-story building or between the ceiling
20) Plenum
and the floor of the next higher level in a multi-story
building.

Used for high data transmission rates to reduce losses

21) Coaxial
and isolate transmission path.

Refers to the woven stranded mesh that surrounds

22) Shielding
some types of coaxial cables.

One layer of foil insulation and one layer of braided

23) shielding. Dual shielded

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Rigid air-filled; solid

24) Types of coaxial cables.
flexible

26) Uniformly distributed throughout the length of the line. Distributed parameters

27) Transmission characteristics of a transmission line. Secondary constants

28) Impedance seen looking into an infinitely long line. Surge impedance

Expressed the attenuation and the phase shift per

29) Propagation constants
unit length of a transmission line.

Ratio of the actual velocity of propagation of an

30) electromagnetic wave through a given medium to Velocity factor.
the velocity of propagation through a vacuum.

31) Relative permittivity of a material. Dielectric constant

Conductor loss, radiation

loss, dielectric heating
32) Several ways in which signal power is lost.
loss, coupling loss and
corona

Voltage that propagates from the source toward the

33) Incident voltage
load.

Voltage that propagates that propagates from the

34) Reflected voltage
load toward the source.

35) Transmission line with no reflected power. Flat or non resonant line

Vector quantity that represents the ratio of reflected

36) voltage to incident voltage or reflected current to Reflection coefficient
incident current.

37) Incident power is absorbed by the load. Matched line

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Unmatched or
38) Incident power returned (reflected) to the source.
mismatched line

39) Two travelling waves set up an interference pattern. Standing wave

Ratio of the maximum voltage to the minimum

40) voltage or the maximum current to the minimum Standing-wave ratio
current of a standing wave on a transmission line.

Used to matched transmission lines to purely resistive

Quarter-wavelength
41) loads whose resistance is not equal to the
transformers
characteristic impedance of the line.

A technique that can be used to locate an Time domain

42)
impairment in a metallic cable reflectometry (TDR)

43) Return signal. Echo

Simply a flat conductor separated from a ground

44) Microstrip
plane by an insulating di-electric material.

Simply a flat conductor sandwiched between two

45) Stripline
ground planes.

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CHAPTER 13 OPTICAL FIBER TRANSMISSION MEDIA

# DEFINITIONS TERMS

Optical communications
1) Uses light as a carrier of information.
system

Electronic communications system is directly Information-carrying

2)
proportional to bandwidth. capacity

Bandwidth of an analog communications system as

3) bandwidth utilization ratio
a percentage of its carrier frequency.

Device constructed from mirrors and selenium

4) detectors that transmitted sound waves over a beam Photophone
of light.

5) Experimented with an apparatus called photophone. Alexander Graham Bell

6) Used extensively in medical field. Flexible fiberscope

Laser (light amplification

7) Invented in 1960.
by stimulated emission of
radiation)

1. wider bandwidth and

greater information
capacity
2.immunity to crosstalk
3. immunity to statistic
interference
8) Advantages of Optical Fiber cables. 4. environmental
immunity
5. safety and
convenience
6. lower transmission loss
7. security
8. durability and reliability
9. economics
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1. interfacing cost

2. strength

3. remote electrical
power
9) Disadvantages of Optical Fiber cables.
4. optical fiber cables are
more susceptible to losses
introduced by bending
the cable

5. specialized tools,
equipment, and training

Reduces the possibility of the occurrence of a

10) Stress corrosion
detrimental phenomenon.

12) Protective coating. Buffer jacket

Increases the tensile strength of the over all cable

14) Strength member
assembly.

Process of decaying from one energy level to Spontaneous decay or

15)
another energy level. spontaneous emission

Science of measuring only light waves that are visible

16) Photometry
to human eye.

Measures the rate at which electromagnetic waves

17) Optical power
transfer light energy.

18) Spectral separation of white light. Prismatic refraction

Simply the ratio of velocity of propagation of a light

19) Refractive index
ray in free space to the velocity of propagation of a
light ray in a given material.

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Angle at which the propagating ray strikes the

20) Angle of incidence
interface with respect to the normal.

Angle formed between the propagating ray and the

21) normal after the ray has entered the second Angle of refraction
medium.

Closely related to acceptance angle and is the

22) figure of merit commonly used to measure the Numerical aperture
magnitude of the acceptance angle.

23) Simply means path. Mode

24) More than one path. Multimode

Probably the most important characteristic of the

26) Power loss
cable.

1. ultra violet absorption

Three factors that contribute to the absorption losses 2. infrared absorption

27)
in optical fibers:
3. ion resonance
absorption

28) Caused mainly by small bends and kinks in the fiber. Radiation losses

Caused by excessive pressure and tension and

29) generally occur when fibers are bent during handling Contants-radius bends
or installation.

Caused by the difference in the propagation times of

30) Modal dispersion
light rays that take different path down a fiber.

A p-n junction made from two different mixtures of

32) Mojunction structure
the same types of atom.

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Generally constructed of silicon-doped gallium-

33) Epitaxially grown
arsenide.

Homojunction LED’s output approximately 500 µ at a

34) Planar diffused
wavelength of 900 nm.

1. increase in current
density generates a more
brilliant light spot.

2. smaller emitting area

makes it easier to couple
Advantages of heterojunction devices over
its emitted light into a
homojunction devices;
fiber.

3. small effective area

has a smaller
capacitance, which
allows the planar
heterojunction LED to be
used at a higher speed.

Depletion-layer photo diode and is probably the

36) most common device used as a light detector in fiber PIN diode
optic communications system.

1. responsivity

2. dark currents

37) Characteristic of a light detector. 3. transit time

4. spectral response

5. light sensitivity

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CHAPTER 14 ELECTROMAGNETIC WAVE PROPAGATION

# DEFINITIONS TERMS

Propagation of electromagnetic waves often called

1) radio-frequency (RF) propagation or simply radio Free-space
propagation.

2) Electrical energy that has escaped into free space. Electromagnetic wave

The orientation of the electric field vector in respect

3) Polarization
to the surface of the Earth.

4) Polarization remains constant Linear Polarization

Horizontal Polarization
5) Forms of Linear polarization
and Vertical Polarization

Polarization vector rotates 360◦ as the wave moves

6) one wave-length through the space and the field Circular Polarization
strength is equal at all angles of polarization.

7) Field strength varies with changes in polarization.

Elliptical Polarization

Used to show the relative direction of

8) Rays
electromagnetic wave propagation.

Formed when two points of equal phase on rays

9) Wavefront
propagated from the same source are joined
together.

A single location from which rays propagate equally

10) Point source
in all directions.

11) Invisible force field produced by a magnet, such as a Magnetic Field

conductor when current is flowing through.

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Strength of a magnetic field (H) produced around a

12)
conductor is expressed mathematically as:

Invisible force fields produced by a difference in

13) Electric fields
voltage potential between two conductors.

Electric filed strength (E) is expressed mathematically

14) 2
as:

Dielectric constant of the material separating the two

15) Permittivity
conductors.

16) The permittivity of air or free space is approximately. 8.85 x 10 -12 F/m

The rate at which energy passes through a given

17) Power density
surface area in free space.

Intensity of the electric and magnetic fields of an

18) Field intensity
electromagnetic wave propagating in free space.

Mathematically power density is expressed as:

19) P = €H W/m2

The characteristic impedance of a

lossless transmission medium is equal to the square 1/2
20) Zs = (µo 0)
root of the ratio of its magnetic permeability to its
electric permittivity.

Point source that radiates power at a constant rate

21) Isotropic radiator
uniformly in all directions.

Power density is inversely proportional to the square of

22) Inverse Square Law
the distance from the source.

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23) Propagation medium. Isotropic medium

Waves propagate through free space, they spread

24) Attenuation
out, resulting in a reduction in power density.

25) Reduction of Power. Absorption Loss

Reduction in power density with distance is equivalent

26) Wave attenuation
to a power loss.

27) Spherical spreading of the wave. Space attenuation

28) One with uniform properties throughout. Homogeneous medium

Absorption coefficient varies considerably with

29) location, thus creating a difficult problem for radio Inhomogeneous medium
systems engineers.

Refraction, Reflection,
30) Optical properties of Radio Waves.
Diffraction and
Interference

31) Bending of the radio wave path. Refraction

Square root of the dielectric constant and is

32) Refractive index; n = (k)
expressed in:

(k) Equivalent dielectric constant relative to free

33)
space (vacuum). K = (1- 81N/f2)1/2

Boundary between two media with different densities.

34) Plane

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Imaginary line drawn perpendicular to the interface

35) Normal
at the point of incidence.

Angle formed between the incident wave and the

36) Angle of Incidence
normal.

Angle formed between the refracted wave and the

37) Angle of Refraction
normal.

Ratio of velocity of propagation of a light ray in free

38) space to the velocity of propagation of a light ray in Refractive Index
a given material.

Perpendicular to the direction of propagation

39) Density gradient
(parallel to the waveform)

40) To cast or turn back. Reflect

Ratio of the reflected to the incident voltage

42) Reflection Coefficient
intensities.

Portion of the total incident power that is not Power transmission

43)
reflected. coefficient

44) Fraction of power that penetrates medium 2. Absorption coefficient

Incident wave front strikes an irregular surface, it is

45) Diffuse reflection
randomly scattered in many directions.

Specular (mirrorlike)
46) Reflection from a perfectly smooth surface.
reflection

47) Semirough surfaces

Surfaces that fall between smooth and irregular.

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Semirough surface will reflect as if it were a smooth

surface whenever the cosine of the angle of Rayleigh criterion
48) incidence is greater than λ/8d, where d is the depth
of the surface irregularity and λ is the wavelength of Cos θi > λ/8d
the incident wave.

Modulation or redistribution of energy within a

49) wavefront when it passes near the edge of an Diffraction
opaque object.

Diffraction occurs around the edge of the obstacle,

51) Shadow zone
which allows secondary waves to “sneak” around the
corner of the obstacle.

States that the total voltage

54) intensity at a given point in space is the sum of the Linear Superposition
individual wave vectors.

Electromagnetic waves travelling within Earth’s

52) Terrestial waves
atmosphere.

Communications between two or more points on Terrestial radio

53)
Earth. communications

54) Used for high-frequency applications. Sky waves

Earth –guided electromagnetic wave that travels

55) Surface wave
over the surface of earth.

Relative
Surface
Conductivity
Seawater Good
Flat, loamy soil Fair
Relative Conductivity of Earth Surfaces Large bodies of
56) Fair
freshwater
Rocky terrain Poor
Desert Poor
Jungle Unusable

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1. Ground waves require

a relatively transmission
power.
2. Ground waves are
limited to very low, low,
and medium frequencies.
57) Disadvantages of surface waves.
3. Requiring large
antennas.
4. Ground losses vary
considerably with surface
material and
composition.

1. Given enough transmit

power, ground waves
can be used to
communicate between
any two locations in the
58) Advantages of ground wave propagation. world.

2. Ground waves are

relatively unaffected by
changing atmospheric
conditions.

Travel essentially in a straight line between the

59) Direct waves
transmit and receive antennas.

Line-of-Sight (LOS)
60) Space wave propagation with direct waves.
transmission

The curvature of Earth presents a horizon to space

61) Radio Horizon
wave propagation.

Occurs when the density of the lower atmosphere is

62) such that electromagnetic waves are trapped Duct propagation
between it and Earth’s surface.

Lowest layer of the ionosphere and is located

63) D Layer
approximately between 30 miles and 60 miles (50 km
to 100 km) above Earth’s surface.
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Located approximately between 60 miles and 85

64) E Layer
miles (100 km to 140 km) above Earth’s surface.

65) The upper portion of the E layer. Sporadic E layer

Made up of two layers, F 1 and F 2 layers.

66) F Layer

Highest frequency that can be propagated directly

67) upward and still be returned to Earth by the Critical frequency
ionosphere.

Maximum vertical angle at which it can be

68) propagated and still be refracted back by the Critical Angle
ionosphere.

A measurement technique used to determine the

69) Ionospheric Sounding
critical frequency.

Height above the Earth’s surface from which a

70) Virtual Height
refracted wave appears to have been reflected.

Highest frequency that can be used for sky wave

Maximum Usable
71) propagation between two specific points on Earth’s
Frequency (MUF)
surface.

MUF = critical
72)
Secant law. frequency/cosθi

Operating at a frequency of 85% of the MUF provides Optimum Working

73)
more reliable communications. Frequency (OWF)

Minimum distance from a transmit antenna that a sky

74) Skip distance
wave at a given frequency will be returned to Earth.

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The area between where the surface waves are

75) completely dissipated and the point where the first Quiet, or skip, zone
sky wave returns to Earth.

Formed by the ionosphere is raised, allowing sky

76) waves to travel higher before being returned to Ceiling
Earth.

77) Define as the loss incurred by an electromagnetic Free-space path loss

waves as it propagates in a straight line through a
vacuum with no absorption or reflection of energy
from nearby objects.

78) Occurs simply because of the inverse square law. Spreading loss

79) Variation in signal loss. Fading

80) To accommodate temporary fading, an additional Fade margin

loss is added to the normal path loss Fm = 30 logD + 10log
(6ABf) – 10log (1-R) – 70

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CHAPTER 15 ANTENNAS AND WAVEGUIDES

# DEFINITIONS TERMS

A metallic conductor system capable of radiating

1) Antenna
and capturing electromagnetic energy

Couples energy from a transmitter to an antenna or Transmission Lines

2)
from antenna to a receiver

A special type of transmission line that consists of a

Waveguide
3) conducting metallic tube through which high-frequency
electromagnetic energy is propagated.

Electrical energy that has escaped into free space in

Radio Waves
4) the
form of transverse electromagnetic waves

The plane parallel to the mutually perpendicular lines

5) of Wavefront
the electric and magnetic fields.

6) The ratio of radiated to reflected energy. Radiation Efficiency

Antenna wherein two conductors are spread out in a

Quarter Wave Antenna
7) straight line to a total length of one quarter
wavelength.

Vertical Monopole or
8) Another name for quarter wave antenna.
Marconi

9) A half-wave dipole. Hertz Antenna

A special coupling device that can be used to

Diplexer
10) direct the transmit and receive signals and provide the
necessary isolation.

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A polar diagram or graph representing field strengths

Radiation Pattern
11) or power densities at various angular positions relative
to an antenna.

Radiation pattern plotted in terms of electric field Absolute Radiation

12)
strength or power density. Pattern

Radiation pattern plots field strength or power density

13) Relative Radiation
with respect to the value at a reference

14) The primary beam of an antenna. Major Lobes

The major lobes that propagates and receive Front Lobe

15)
the most energy.

16) Lobes adjacent to the front lobe. Side lobes

17) The secondary beam of an antenna. Minor Lobes

18) Lobes in a direction exactly opposite the front lobe Back Lobe

The ratio of the front lobe power to the back lobe Front to Back Ratio
19)
power.

20) The ratio of the front lobe to a side lobe. Front to Side Ratio

The line bisecting the major lobe, or pointing from

Line of Shoot or Point
the center of the antenna in the direction of
21) of Shoot
maximum
radiation.

Omni-directional
Antenna that radiates energy equally in all directions.
22) Antenna

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Radiates power at a constant rate uniformly in all Isotropic Radiator

23)
directions.

24) The direction in which an antenna is always pointing. Maximum Radiation

It is defined as an equivalent transmit power. It stands

25) EIRP
for Effective Isotropic Radiated Power.

The equivalent power that an isotropic antenna

Effective Radiated Power
would have to radiate to achieve the same power
26) (ERP) or (EIRP)
density in the chosen direction at a given point as
another antenna.

The power density in space and the actual power

Captured Power Density
27) that a receive antenna produces at its output
terminals.

28) It describe the reception properties of an antenna Capture Area

29) Another name for capture area. Effective Area

The relationship of captured power to the received

30) power density and the effective capture area of the Directly Proportional
received antenna.

It refers to the orientation of the electric field radiated Polarization

31)
from the antenna.

The angular separation between the two half-power

32) (-3dB) points on the major lobe of an antenna's plane Antenna Beamwidth
radiation pattern.

The frequency range over which antenna operation Antenna Bandwidth

33)
is satisfactory.

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Feedpoint
34) Another name for antenna input terminal

The feedpoint presents an ac load to the transmission Antenna Input

35)
line. Impedance

The simplest type of antenna.

Another names for elementary doublet
 Short Dipole, Elementary Doublet
36)
 Elementary Dipole
 Hertzian Dipole

37) Any dipole that is less than one-tenth wavelength Electrically Short

Hertz antenna is name after him and he was the first

38) to demonstrate the existence of electromagnetic Heinrich Hertz
waves.

A single pole antenna one quarter wavelength long,

mounted vertically with the lower end either
39) Marconi Antenna
connected directly to ground or grounded through
the antenna coupling network.

Must be close
40) Main disadvantage of Marconi Antenna.
to the Ground

A technique use to increase the electrical length of Loading

41)
an antenna

A coil added in series with a dipole antenna which Loading Coil

42)
effectively increases antenna's electrical length.

A loading coil approximately increases the radiation 5 Ohms

43)
resistance of the antenna.

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An individual radiator, such as a half or quarter

wave dipole.
Two types of antenna elements
 Driven
Antenna Element
44)  Parasitic
Two Elements of a single antenna
 Two Wire
 Folded Dipole

Its purpose is to increase the directivity and

Array
45) concentrate
the radiated power within a smaller geographic area.

Elements that are directly connected to the

46) transmission Driven
line and receive power from the source.

Elements are not connected to the transmission line;

47)
they receive energy only through mutual induction with
a driven element. Parasitic

A parasitic element that is shorter that its associated

Director
48) driven element.

Radiation pattern depends on the relative phase of Driven

49)
feeds.

50) The simplest type of antenna arrays. Broadside Arrays

A widely used antenna commonly uses a folded

dipole
Yagi Uda
51) as the driven element and named after two Japanese
scientists.

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7 dB and 9 dB
52) Typical directivity of a yagi-uda antenna.

Formed by placing two dipoles at right angles to Turnstile Antenna

53)
each other.

54) A class of frequency-independent antennas. Log Periodic

A broadband VHF or UHF antenna that is ideally

suited
for applications for which radiating circular rather than
horizontal or vertical polarized electromagnetic waves
55) Helical Antenna
are required.
Modes of propagation:
 Normal
 Axial

Antennas having half power beamwidths on the

order
of 1o or less.
Microwave Antenna
56) Three important characteristics:
 Front-to Back Ratio,
 Side-toSide Coupling
 Back-to-Back Coupling

Antenna that provides extremely high gain and

directivity and are very popular for microwave
and satellite communications link.
57)
Two main part
Parabolic Reflector
 Parabolic Reflector
Antenna
 Feed Mechanism

The effective area in a receiving parabolic antenna Capture Area

58)
and is always less than the actual mouth area.

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CHAPTER 16 TELEPHONE INSTRUMENTS AND SIGNALS

# DEFINITIONS TERMS

Process of conveying information from one place

1) Communications
to another.

2) Is a long-distance communications Telecommunications

3) One of the most remarkable devices ever invented. Telephone

Anyone who uses a telephone or a data modem on

Public Telephone
4) a telephone circuit is part of a global
Network
communications network .

The PTN is comprised of several very large

5) corporations and hundreds of smaller independent Telco
companies jointly.

The telephone system as we know it today began as

Alexander Graham Bell
6) an unlikely collaboration of two men with widely
and Thomas A. Watson
disparate personalities:

The simplest and most straightforward form of Plain Old Telephone

7)
telephone service. Service

8) Most fundamental component of a telephone circuit. Subscriber Loop or Local

Loop

An unshielded trwisted-pair transmission line

9) consisting of two insulated conductors twisted Local Loop
together

Comes from the Greek word "tele" meaning from afar

10) Telephone
and phone, meaning sound, voice, or voiced sound.

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The first telephone set that combined a transmitter

11) and receiver into a single handheld unit was Butterstamp Telephone
introduced in 1878

12) Helps prevent the speaker from talking too loudly Sidetone or Talkback

13) Local Loop

The pair of wores connecting.

A series of telephone connection interfaces that are

14) registered with the U.S. Federal Communications RJ or Registered Jacks
Commission.

The most common telephone jack in use today and

15) RJ-11
can have up to six conductors.

An apparatus that creates an exact likeness of sound

16) Telephone Set
waves with an electric current.

Is originally an electromagnetic bell, placed directly

17) Ringer Circuit
across the tip of the ring of the local loop.

Alert the destination party

18) Purpose of a Ringer. of incoming calls

19) Sometimes called a Switch Hook. On/Off Hook Circuit

Helps solve an important transmission problem in

20) Equalizers
telephone set design.

21) Is the transmitter of the telephone. Microphone

Converts acoustical signals in the form of sound

22) pressure waves from the caller to electrical signals Microphone
that are transmitted into the telephone network.

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Enables the subscriber to output signals representing

23) Dialing Circuit
digits.

Signaling messages can be subdivided further into

Alerting, Supervising,
one or four categories:
24) Controlling, and
Addressing

25) Indicate a request for service. Alerting Signals

26) Provide call status information. Supervising Signals

27) Provide information in the form of announcements. Controlling Signals

28) Provide the routing information. Addressing Signals

Is strictly for signaling between a subscriber's location

29) and the nearest telephone office or message DTMF
switching center.

Are used to transfer digits and control signals

30) Multifrequency Tones
between switching machines.

Are combinations of two frequencies that fall within

31) the normal speech bandwidth so they can be MF Tones
propagated over the same circuits as voice.

Congestion Tone or No-

32) Equipment Busy Signal is sometimes.
Circuit-Available

Occurs whenever the system is overloaded and more

33) Blocking
calls are being placed than can be completed.

Is sent from a central office to a subscriber whenever

34) there is an incoming call. Ringing signal

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Telephones that operate with out the cords attached

35) Cordless Telephones
to the handset.

Relay radio signals and messages from wire line and

36) cellular telephones to subscribers carrying portable Paging Transmitters
receivers.

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CHAPTER 17 THE TELEPHONE CIRCUIT

# DEFINITIONS TERMS

It comprised of two or more facilities, interconnected

Telephone Circuit
1) in tandem, to provide a transmission path between a
source and a destination.

2) The information transferred in a telephone circuit Message

The circuit used in transferring information in a Message Circuit

3)
telephone circuit.

The network bandwidth for a standard voice-band

4) 4 kHz
message channel.

Unused frequency bands located between Guard Bands

5)
information signals.

Effective channel bandwidth for a voice-band 300 Hz to 3000 Hz

6)
message signal.

The only facility required by all voice-band circuits, as

Local Subscriber
7) it is the means by which subscriber locations are
Loop
connected to the local telephone company

Two components
The primary caused of attenuation and phase found on local loops:
8) distortion on a telephone circuit.
Loading Coils
Bridge Taps

The largest cable used in a local loop,

Feeder Cable (F1)
9) usually 3600 pair of copper wire placed underground
or in conduit.

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A cross-connect point used to distribute the larger

10) Serving Area Interface
feeder cable into smaller distribution cables.

A smaller version of a feeder cable containing less

11) Distribution Cable
wire pairs.

A device that serves as the demarcation point Subscriber or Standard

12) between local telephone company responsibility and Network Interface (SNI)
subscriber responsibility for telephone service.

The final length of cable pair that terminates at the

13) Drop Wire
SNI.

That portion of the local loop that is strung between

14) poles. Aerial

Distribution Cable
The location where individual cable pairs within a
and Drop
15) distribution cable are separated and extended to
Wire Cross Connect
the subscriber's location on a drop wire.
Point

16) Adding inductors periodically in series with the wire. Loading

17) The inductor in loading technique. Loading Coil

An irregularity frequently found in cables serving

18) Bridge Tap
subscriber location.

A loss that allows signals to split and propagation Bridging Loss

19)
down more than one wire introduced by bridge taps.

Weighting network introduced by AT & T to

20) C-Message Weighting
accomplish equal magnitude of noise signals.

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The most annoying frequency to human (i.e. the best 1000 Hz

21)
frequency response).

The basic yardstick used for making power

Decibel (dB)
22) measurements
in communications.

Transmission
The optimum level of a test tone on a channel at som
Level Point
23) point in a communications system. It is used for
(TLP)
voice circuits.

The ratio in dB of the power of a signal at that point Transmission Level

24) to the power the same signal would be at 0 dBm (TL)
transmission level point.

0 dBm
25) The reference for TLP.

Data Level Pint

A parameter equivalent to TLP except it is used as a
26) (DLP)
reference for data transmission.

dBmO
27) dBm reference to a zero transmission level point.

28) dB reference value for noise reading. reference noise (rn)

dB level of noise with respect to reference noise dBrn

29)
(- 90 dBm).

Similar to dBrn except it is the dB value of noise with

respect to reference noise using C-message dBrnc
30)
weighting

Noise readings taken with a filter that has a flat

31) dBrn 3 kHz Flat
frequency response from 30 Hz to 3 kHz

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32) The amount of noise in dBrnc corrected to a 0 TLP dBrncO

Transmission parameters which include terminal Interface

34) impedance, in band and out of band signal power, Parameters
test signal power and ground isolation.

Transmission parameters which includes noise

Facility Parameters
35) measurements, frequency distortion, phase distortion,
amplitude distortion and non linear distortion.

The difference in circuit gain experienced at a

particular frequency with respect to the circuit gain
of a reference frequency.
Attenuation
36) Distortion
Another names attenuation distortion:
 Frequency Response,
 Differential Gain
 1004-Hz Deviation

An indirect method of evaluating the phase delay

37) characteristics of a circuit. Envelope Delay Distortion

Basic Voice-Band
It satisfies the minimum line conditioning
38) Channel
requirements

Another name for basic voice-band.

39) Basic 3002 Channel

40) Specifies the maximum limits for attenuation distortion C-type Conditioning
and envelope delay distortion.

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Classifications of C-type:
 C1
 C2
 C3
 C4
 C5

Classification of C-type conditioning pertains to two

41) point and multi point circuits. C1 and C2

C-type conditioning used for access lines and trunk C3

42)
circuits associated with private switched networks.

C-type conditioning pertains to two point and multi

43) C4
point circuits with a maximum of four stations

44) C-type conditioning pertains to two point circuits only C5

A relatively low-capacity switching machine where Private Branch Exchange

45) the subscribers are generally limited to stations within (PBX)
the same building or building complex.

The frequency response of a transmission medium

46) Attenuation Distortion
referenced to 1004 Hz test tone.

Linear Phase vs.

47) A requirement for error free data transmission.
Frequency

The difference in phase shifts with respect to

48) frequency that signals experience as they propagate Delay Distortion
through a transmission medium.

The time delay encountered by a signal as it

Propagation Time
49) propagates
from source to a destination.

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Phase Delay
50) The delay measured in angular units.

The actual time required for a particular frequency

51) to propagate from a source to a destination through Absolute Phase Delay
a communications channel.

The time required to propagate a change in an

52) Envelope Delay
AM envelope through a transmission medium.

The phase difference at the different carrier

53) Envelope Delay Distortion
frequencies.

It sets the minimum requirements for signal to noise

55) ratio and nonlinear distortion. D-Type Line Conditioning

The data transmission rate when D type conditioning

56) is mandatory. 9600 bps

57) Telephone industry standard test tone frequency 1004 Hz

C-message Noise
Measurement that determine the average weighted
58) Measurement
rms noise power.

A communications term that indicates the presence

of a signal power comparable to the power of an actual Loaded
59)
message transmission.

Characterized by high amplitude peaks of short

Impulse Noise
60) duration having an approximate flat frequency
spectrum

A sudden, random change in the gain of a circuit Gain Hit

61)
resulting in a
temporary change in the signal level.
Dropout
62) A decrease in circuit gain of more than 12 dB lasting
longer than 4 ms.

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63) A sudden, random changes in the phase of a signal. Phase Hits (Slips)

A form of incidental phase modulation - a

continuous, Phase Jitter
64)
uncontrolled variation in the zero crossings of a signal.

The presence of one or more continuous, unwanted Single Frequency

65) tones within a message channel. Interference

66) Unwanted tones within a message channel. Spurious Tones

The frequency of the signal changes during Frequency Shift

67)
transmission.

It occurs in coherent SSBSC systems when the

received carrier is not reinserted with the exact
Phase Intercept Distortion
68) phase relationship to the received signal as the
transmit carrier possessed.

It occurs in coherent SSBSC systems when the

received carrier is not reinserted with the exact
69) Phase Intercept Distortion
phase relationship to the received signal as the
transmit carrier possessed.

70) A four wire circuit an interface. Hybrid Set

Terminating Set
Another name for hybrid set.
71)

Any disturbance created in a communications

Crosstalk
72) channel by signals in other communications
channels.

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Annoying and objectionable because the listener

73) Intelligible crosstalk
senses a real or fancied loss of privacy

It does not violate privacy, although it can still

74) Unintelligible crosstalk
be annoying.

A direct result of nonlinear amplification in analog

75) Nonlinear Crosstalk
communications system.

Electromagnetic coupling between two or more

76) Coupling Crosstalk
physically isolated transmission media.

Interference caused by inadequate control of the Transmittance

77) transfer characteristics or transmittance of networks. Crosstalk

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CHAPTER 18 THE PUBLIC TELEPHONE NETWORK

# DEFINITIONS TERMS

It uses the largest computer network in the world to

Public Telephone
1) interconnect millions of subscribers in such a way that
Network (PTN)
the myriad of companies function as a single entity.

Identifies and connects the subscribers to a suitable

2) Switching
transmission path.

Supply and interpret control and supervisory signals Signaling

3)
needed to perform the operation.

4) The public telephone companies. Service Providers

Equipment and facilities that are available to Common Usage

5) all public subscribers to the network. Equipment

Another name for Public Switched Telephone

Dial-Up Network
6) Network (PSTN).

The transmittal of digital information between two

7) pieces of digital equipment. Data Transmission

Any device used to originate and terminate calls and

to transmit and receive signals into and out of the Instrument
8)
telephone network.

Station Equipment
9) The instrument is often referred.
The location of the equipment.
10) Station
Subscriber
11) The operator or user of the instrument.
The dedicated cable facility used to connect an
instrument at a subscriber's station to the closest Local Loop
12)
telephone office.

Similar to local loop except trunk circuits are used to

Trunk Circuits
11) interconnect two telephone offices.

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The dedicated cable facility used to connect an

12) instrument at a subscriber's station to the closest Local Loop
telephone office.

Similar to local loop except trunk circuits are used to

13) Trunk Circuits
interconnect two telephone offices..

A central location where subscribers are

14) interconnected, either temporarily or on permanent Exchange
basis.

Programmable matrices that provide temporary signal Switching Machines

15)
paths between two subscribers.

16) Exchanges connected directly to local loops. Local Exchanges

The first commercial telephone switchboard began

17 January 28, 1878
operation New Haven, Connecticut.

18) The first local telephone exchanges. Switchboards

A system of sensors, switches, and other electrical and

electronic devices that allows subscribers to give Automated Switching
19)
instructions directly to the switch without having to go System
through an operator.

Allowed subscribers to manually dial the telephone

20) Mechanical Dialer
number of the party they wished to call.

21) Commonly called for stepper or step-by-step (SXS). Strowger Switch

22) Simply the path over which voice, data, or video signals Circuit
propagate.

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A programmable matrix that allows circuits to be

Circuit Switch
23) connected tom one another.

Telephone call completed within a single local

24) Intraoffice Call
exchange.

Telephone calls placed between two stations that are

25) Interoffice calls
connected to different local exchanges.

26) Another name for interoffice calls. Interswitch Calls

Telephone switching machines in local exchanges are

27) Trunks or Interoffice Trunk
connected to other local exchange office.

It is used to interconnect local offices that do not have

Tandem Office
28) interoffice trunks directly between them. An exchange
without any local loops connected to it.

29) Switches that interconnect local offices only. Tandem

Tandem Trunk or
30) Trunk circuits that terminates in tandem switches.
Intermediate Trunk

Interstate long distance telephone calls require a

31) Toll Office
special telephone office.

North American
Provides telephone numbering system for the United Telephone
32)
States, Mexico and Canada. Numbering Plan (NANP)

It allows many subscriber to share a limited number of Concentrator

33)
lines to a central office switch.

A path between two subscribers and is comprised of

34) Route
one or more switches, two local loops; and possibly
one or more trunk circuits.

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A call that call cannot be completed because the

35)
necessary trunk circuits or switching paths are not
Blocking
available, the calling party receives an equipment
busy signal.

A local exchange where subscriber loops terminated Class 5 End Switching

36)
and received dial tone. Office

Class 4 office having only outward and inward calling Class 4P Switching
37)
service. Office

Class 4 office provided human operators for both

38) Class 4C
outward and inward calling service.

Switching office that provide service to small

Class 3 Primary Center
39) groups of class 4 offices within a small area
of a state.

Sectional centers that could provide service to

40) geographical regions varying in size from part of a Class 2 Sectional
state to all of several states.

Regional centers were the highest ranking office in the

Class 1 Regional
41) DDD network in terms of the size of the geographical
Center
are served and the trunking options available.

Toll trunks in tandem, excluding the two terminating Intermediate Links

42)
links at the ends of the connection.

Common Channel
A global standard for telecommunications defined by
43) Signaling System No. 7
the ITU.
(SS7 or C7)
Refers to the exchange of information
between call components required to Signaling
44)
provide and maintain service.

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An architecture for performing out of band signaling in SS7

45)
support of common telephone system functions.

Long distance access is now accomplished Point of Presence

47)
through an access point. (POP)

A telecommunications term that describes the

48) legal boundaries for the responsibility of POP
maintaining equipment and transmission lines.

Provide access to the SS7 network, access to

49) databases used by switches inside and outside Signaling Points
the network.

Codes that are carried in signaling messages

50) exchanged between signaling points to identify Point Codes
the source and destination of each messages.

Service Switching
Local telephone switches equipped with SS7
51) Points
compatible software and terminating signal links.

52) The packet switches of the SS7 network. Signal Transfer Points

It serves as an interface to telephone company

53) Service Control Points
databases.

54) Another name for service control points. Signal Control Points

Provides access from one level of the protocol to

55) Primitive
another

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CHAPTER 19 CELLULAR TELEPHONE CONCEPTS

# DEFINITION TERMS

The term for mobile telephone services which Mobile Telephone

1) began in 1940s and are sometimes called Manual Manual System (MTSs)
telephone systems.

2) The frequency used by MTSs. 35 MHz-45MHz

Switch that was used by MTS to activate the

3) Push-to-Talk (PTT)
transceiver.

It was introduced in 1964 which used several carrier

Improved Mobile
frequencies and could, therefore, handle several
4) Telephone System
simultaneous mobile conversations at the same
(IMTS)
time.

The term suggested any radio transmitter, receiver,

5) or transceiver that could be moved while Mobile
operation.

The term that described a relatively small radio unit

Portable
6) that was handled, battery powered, and easily
carried by a person moving at walking speed.

It is similar to two-way mobile radio in that most

7) communications occurs between base stations Cellular Telephone
and mobile units.

It operates on half duplex and use PTT transceivers.

examples of two-way radio:
8)  Citizens Band (CB) Two-Way Radio
 Public land mobile radio

A one to one system that permits two-way

9) simultaneous transmissions and operates the same Mobile Telephone
way as the standard wire line telephone service.
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Hinted of a cellular telephone scheme that

10)
he referred to as simply a small-zone radio telephone E.K. Jett
system in the July 28, 1945.

On June 17, 1946, they introduced the first American

AT&T and Southwestern
11) commercial mobile radio-telephone service to
Bell
private customers.

A radio telephone service introduced by AT&T in

12) Highway Service.
1947.

Unveiled the most famous mobile telephone to date:

13) the fully mobile shoe phone in 1966 in a television Don Adams
show called Get Smart.

The year when FCC granted AT&T the first license to

14) operate a developmental cellular telephone service 1975
in Chicago.

A satellite-based wireless personal communications

15) Iridium
satellite (PCSS)

16) Another term for cellular telephone. Cellular Radio

17) A large geographic market area. Coverage zone

It is employed to increase the capacity of a mobile

18) Frequency Reuse
telephone channel.

The shape that was used because it provides the

most effective transmission by approximating a
19) circular pattern while eliminating the gaps present Honeycomb
between adjacent circles.

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20 Large cells that typically has 1 mile and 15 miles Macrocells

radius with base station transmit power 1W and 6 W.
The smallest cells that typically has radius of 1500 feet
or less with base station transmit powers between 0.1 Microcells
21
W and 1 W.

The process in which the same set of frequencies can

be allocated to more than one one cell, provided
the cells are separa Frequency Reuse
22)
ted by sufficient distance.

23) A geographic cellular radio coverage area

cluster
containing three groups of cells.

24) Typically equal to 3,7, or 12. Cluster size

The process of finding the tier with the nearest

25) First Tier
co-channel cells

26) Two cells using the same set of frequencies. Co-channel cells

The interference between the co-channels cells.

Adding radio channels to a system:

 Decreasing the transmit power per cell
27) Co-channel Interference
 making cells smaller
 filling vacated coverage areas with
new cells

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The ratio of the cell radius

28) The ratio of the cell radius and distance from the
and distance from the
nearest co-channel cell
nearest co-channel cell

Channel next to one another in the frequency

29) Adjacent Channel
domain.

It results from imperfect filters in receivers that allow Adjacent-Channel

30)
nearby frequencies to enter the receiver. Interference

Most prevalent when a mobile unit is receiving a

31) Near-Far Effect
weak signal from the base station.

The area of a cell, or independent component

coverage areas of cellular system is further Cell Spliting
32)
subdivided thus creating
more areas.

Occurs when number of the number of subscriber

33) wishing to place a call at any given time equals the Maximum Traffic Load
number of channels in the cell.

A condition occurs when a new call is initiated in an

34) Blocking
area where all the channels are in use.

Smaller areas when a single omnidirectional antenna

35) is replaced by several directional antennas, each Sectors
radiating within smaller area.

36) Using directional antennas. Sectoring

37) Placing two receive antennas one above the other. Space Diversity

A means of avoiding full-cell splitting where the entire

38) area would otherwise need to be segmented into Dualization
smaller cells.

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A means of avoiding co-channel interference,

although it lowers the capacity of a cell by enabling Segmentation
39)
reuse inside the reuse distance which is normally
prohibited.

The locations of radio-frequency transceivers.

40) It serves are central control for all users within Base Stations
that cell.

41) It handles all cell-site control and switching functions. Cell-Site Controller

Occurs when a mobile unit moves from one cell to

42) Roaming
another company’s service.

It controls channel assignment, call processing, call

setup and call termination.
Different Names:
 Electric Mobile Exchange (EMX)- Bell
Mobile Telephone
Lab.
43) Switching Office (MTSO)
 AEX- Ericcson
 NEAX-NEC
 Switching Mobile Center (SMC)
 Master Mobile Center (MMC)-Novatel
 Mobile Switching Center- PCS netwroks

The transfer of a mobile unit from one base station’s

control to another base station’s control.

Four stages:
44) Handoff (Handover)
 Initiation
 Resource reservation
 execution
 completion

A connection that is momentarily broken during the

45) Hard Handoff
cell-to-cell transfer. It is a break before-make process.

A flawless hand off with no perceivable interruption

46) Soft Handoff
ofservice.

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It is used by computers that is based on variations in

47) Handoff Decision
signal strength and signal quality.

Either the mobile unit or the network determines the

48) need for a handoff and initiates the necessary Initiation
network procedures.

Appropriate network procedures reserve the

49) Resources Reservation
resources needed to support the handoff.

The actual transfer of control from one base station

50) Execution
to another base station takes place.

Execution Unnecessary network resources are Completion

51)
relinquish and made available to other mobile units.

Roaming from one company’s calling area into

52) Interoperator Roaming
another company’s calling area.

Stands for Electronics Industries

53) Association/Telecommunications Industry Association, EIA/TIA
developed the IS-41 Protocol.

It aligns with a subprotocol of the SS7 protocol stack

that facilitates communications among database
54) other network entities. IS-41

Stands for Cellular Telecommunication Industry

CITA
55) Association.

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The process where a mobile unit notifies a serving

MTSO of its presence and location through a base
station controller.

Components of Cellular Telephone System:

Autonomous Registration
56)  Electronic switching center
 a Cell-site controller
 radio transceiver
 system interconnections
 mobile telephone units
 common communications protocol

A digital telephone exchange located in the MTSO Electronic Switching

57)
that is the heart of a cellular telephone system. Center

X.25
58) A datalink protocol at a transmission rate of 9.6 kbps.

Another name for cell-site controller. Base Station Controller

59)

It manages each of the radio channels at each site

supervises calls, turns the radio transmitter and Cell-site Controller
60)
eceiver on and off, injects data onto the control and
voice channels, and performs diagnostic tests in the
cell-site equipment.

61) Stands for Base transceiver station. BTS

A part of base station subsystem that can be either

62) narrowband FM analog system or either PSK or QAM Radio Transceiver
fro digital systems with effective audio frequency.

63) The radio receiver that detects the strongest signal. Receiver Diversity

It governs the way telephone calls are established

and disconnected.
Examples of Protocol:
64) Communications Protocol
 IS-54
 IS-136.2
 IS-95

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The actual voice channel where mobile users

communicate directly with either mobile and wireline
65) User Channel
subscribers through a base station.

It is used for transferring control and diagnostic

nformation between mobile users and a central
cellular telephone switch through a base station.

Transmit on base station:

 forward control channel
 forward voice channel

66) Receive on base stations: Control Channel

 reverse control channel

 reverse voice channel

types of calls:
 Mobile to wireline
 mobile to mobile
 wireline to mobile

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CHAPTER 20 CELLULAR TELEPHONE SYSTEM

# DEFINITIONS TERMS

Stands for Standard Cellular Telephone

1) CTS
Service

An acronym for Personal Communications

2) PCS
System.

Stands for Personal Communications Satellite

3) PCSS
System.

An acronym for Advanced Mobile Telephone

4) AMPS
System.

Bell Telephone
5) Proposed the cellular telephone concept in 1971.
Laboratories

A standard cellular telephone service (CTS) initially

6) AMPS
placed into operation on Oct. 13, 1983.

It was used by AMPS cellular telephones with a

usable audio-frequency band from 300 Hz to 3 KHz Narrowband Frequency
7)
and a maximum frequency deviation of + 12 KHz Modulation (NBFM)
for 100% modulation.

Correspond to an approximate bandwidth of 30

8) Carson’s Rule
KHz.

A transmission with simultaneous transmission in Full Duplex (FDX)

9)
both direction. or Duplexing

10) It is used in AMPS and occurs when two distinct Frequency-division

frequency bands are provided to each user. Duplexing
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A special device used in each mobile unit to allow

11) simultaneous transmission and reception on Duplexer
duplex channels.

12) Transmissions from base station to mobile units. Forward Links

13) Transmissions from mobile units to base stations. Reverse Links

14) Another name for forward links. Down Links

15) Another term for reverse link. Uplink

Additional frequencies of 10 MHz to the original40

16) MHz band which increased the number of simplex Expanded Spectrum
channels by 166 for a total of 832 (416 Full duplex)

Cellular Geographic
17) Specified frequencies in a small geographic area.
Serving Areas (CGSA)

Defines geographic areas used by marketing Standard Metropolitan

18)
agencies. Statistical Area

A technique used by standard telephone Frequency Division

19)
subscriber to access the AMPS system. Multiple Access

A 34 bit binary code which in the U.S. represents Mobile Identification

20)
the standard 10-digit telephone number. Number (MIN)

A 34 bit binary code permanently assigned to Electronic Serial

21)
each mobile unit. Number (ESN)

22) VIN
Stands for Vehicle Identification Number.

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23) An acronym for Network Interface Card.

NIC

A four bit code which indicates whether the

24) terminal has access to all 832 AMPS channel Station Class Mark (SCM)
or only 666.

A 15 bit binary code used by FCC

25) to an operating company when it issues it a license System Identifier (SID)
To provide AMPS

It is one of the three analog frequencies

(5970 Hz, 6000 Hz, or 6030 Hz) that helps mo Supervisory Audio Tone
26)
bile system distinguish one base station from (SAT)
a neighboring base station.

One of four binary codes, also helps mobile

27) system distinguish one base station from a Digital Color Code (DCC)
neighboring base station.

One set of channels dedicated for exchanging

28) control information between mobile units and Control Channels
base stations.

Also termed as Voice channel, used for

29) propagating actual voice conversations or User Channel
subscriber data.

Another name of control channels.

30) Setup or Paging Channel

31) Sometimes called as Camped. Locked

32) A sequence of alternating 1s and 0s. Dotting Scheme

33) Synchronization Word

A unique sequence of 1s and 0s that enables the

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receiver to instantly acquire synchronization.

It controls or command mobile units to do a Mobile Station Control

34) particular task when the mobile unit has not Messages
been assigned a voice channel.

It is used to indicate the current status of the

35) Busy-idle Bits
reversecontrol channel.

It contains the following:

 System parameter overhead
messages
 global action overhead messages
 control filter messages

36) Typical mobile-unit control messages: Overhead Message

 Initial voice channel designation
messages
 directed retry messages
 alert messages
 change power messages

Transmitted at a 10-kbps rate.

Control data includes:
 page responses Control Data
37)
 access request
 registration requests

38) Transmission of voice. Blank

39) Data transmission. Burst

The entity of SS7 interoffice protocol that

distinguishes the physical components of the
switching network.
Intelligent Network
40)
Switching Network:
 Signal Service Point
 Signal Control Point
 Signal Transfer Point
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A family of mobile or portable radio comuni

cations services which provides servIces to
the individuals and business and is integra
ted with a variety of competing networks. Personal Communications
41) Differences in PCS and cellular telephone System (PCS)
system:
 Smaller Size
 all digital
 additional features

Acronym for Personal Communications

42) PCN
Network.

It is assigned to everyone which is stored the Personal Telephone

43)
on the SS7 network. Number

It determines where and how the call should be Artificial Intelligence

44)
directed. Network (AIN)

A database that stores information about the

Home Location
user,including home subscription information
45) Register (HLR)
and what supplementary services the user is
subscribed to.

A database that stores information pertaining to

Equipment Identification
46) theidentification and type of equipment that
Registry (EIR)
exists in the mobile unit.

It allows all calls to pass through the network

47) to the subscriber except for a minimal Available Mode
number of telephone numbers that can be blocked.

48) Screen Mode

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The PCS equivalent of caller ID.

All calls except those specified by the sub

scriber are automatically forwarded to a for
49) Private Mode
warding destination without ringing the
subscriber’s handset.

No calls are allowed to pass through to the

50) Unavailable Mode
subscriber.

51) PCS operating in the 1900 MHz range. PCS 1900

Interference avoidance scheme which uses

52) voice companding to provide synthetic Interference (MRI)
voice channel quieting.

A narrowband AMPS system that increased

53) the capacity of the AMPS system in large N-AMPS
cellular market.

It is developed with the intent of supporting

United States Digital
54) a higher user density within a fixed
Cellular
bandwidth frequency spectrum.

Cellular telephone systems that use digital

55) Digital cellular
modulation.

Allows one mobile unit to use a channel at

Time-division Multiple
56) the same time by further dividing
Accessing (TDMA)
transmissions within each cellular channel.

Visitor Location Register

57) A database that stores information about
(VLR)
subscriber in a particular MTSOserving

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area, such as whether the unit is on or off

Technique used that allows more mobile-unit

58)
subscribers to use a system at virtually the Time-Sharing Channels
Same time within a given geographical area.

It stands for Electronics Industries

59) Association and Telecommunications EIA/TIA
Industry Association.

It specifies that a mobile station complying

with the IS-54 standard must be capable of Dual Mode
60)
operating in either the analog AMPS or the
digital (USDC) mode for voice transmissions.

It is often called North American Time

61) IS-136.2
Division Multiple Accessing.

It was introduced to provide PSK rather than

FSK on dedicated USDC control channels to in
crease the control data rates and provide
62) IS-54 Rev.C
additional specialized services such as
paging and short messaging between
private mobile user groups.

Allows for brief paging-type messages and

Short e-mail messages that can be read on Short Message Service
63)
the mobile phone’s display and entered
using the keypad.

It was developed to provide a host of new

64) features and services, positioning itself in a IS-136
competitive within the newer PCS systems.

It is used by mobile units to request access

Random Access Channel
to the cellular telephone system. It is a
65) (RACH)
unidirectional channel specified for
transmissions from mobile-base units only.

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SMS point-to-point
It is used to transmit information from base stations Paging and access
66)
to specific mobile stations. response
Channel (SPACH)

It is dedicated to delivering pages and orders.

It transmit :

 paging messages
67) Paging Channel (PCH)
 message-waiting messages
 user alerting messages
 call history count updates
 shared secret data updates

A logical subchannel of SPACH used to carry

Access Response Channel
68) assignments to another resource or other
(ARCH)
responses to the mobile station’s access attempt.

It is used to deliver short point-to-point

69) SMS Channel (SMSCH)
messages to a specific mobile station.

It refers to : F-BCCH, E-BCCH and S-BCCH logical

70) Channel (BCCH)
sub channels.

Broadcasts digital control channel structure Fast Broadcasts Control

71)
parameters. channel (F-BBCH)

Extended Broadcasts
Carries less critical broadcast information than F-
72) Control Channel (E-BBCH)
BCCH intended for mobile units.

Individual mobile units.

SMS Broadcasts Control
73) A logical channels used for sending short
channel (F-BBCH)
messages.

74) Stands for Digital speech interpolation. DSI

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Carries digital voice information and consists of

RDTC and FDTC. Digital Traffic Channel
75)
(DTC)

It consists of an eight bit digital voice color code Coded Digital Verification
76)
number between 1 and 255 appended with four Color Code

77) Mobile-assisted handoff. MAHO

A blank-and burst type of transmission that

replaces
Fast Associated Control
78) digitized speech information with control and
Channel (FACCH)
super
vision messages with in a subscriber’s time slot.

Vector sum exciter linear

79) A special speech coder.
predictive (VSLP)

A special microprocessor that is implemented on Digital Signal Processor

80)
the telephone handset. (DSP)

They are transmitted when a mobile unit begins

81) Shortened Burst
operating in a larger diameter cell.

An access method used with standard analog

AMPS which use frequency channelization
82) approach to FDMA
frequency spectrum management.

It allows users to differentiate from one another by

Code Division Multiple
83) a unique code rather than a frequency or time
Accessing (CDMA)
assignment.

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Stands for Qualcom 9600bps Code-Excited Linear

Predictive coder.
84) QCELP

The concept is to break the message into fixed

85) sized blocks of data with each block transmitted Frequency Hopping
in sequence except on a different carrier.

high bit pseudorandom code is added to a low-

bit rate information signal to generate a high bit
86) rate pseudorandom signal closely resembling Direct-Sequence
noise that contains both the original data signal
and the pseudo random code must be known.

It is a study group which is sometimes referred to

as Pan-European cellular system. This is now
known as the Global System for Mobile
Communications.
Classification of GSM telephone services:
 Bearer Services Groupe Special Mobile
87)  teleservices (GSM)
 supplementary services

Three primary subsystem of GSM:

 Base Station Subsystem
 Network Switching Subsystem
 Operational Support Subsystem

Integrated Services
88) All-digital data Network.
Digital Network (ISDN)

Sometimes known as radio subsystem, provides

Base Station SUbsystem
89) and manages radio frequency transmission paths
(BSS)
between mobile units and the mobile switching
center (MSC)

It manages switching functions for the system and Network Switching

90)
allows MSCs to communicate with other Subsystem (NSS)
telephone networks.
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Absolute Radio-Frequency
The available forward and reverse frequency
91) Channel Numbers
bands are subdivided into 200 KHz wide voice
(ARFCN)
channels.

It provides the vehicle for a new generation of

Mobile Satellite Systems
92) wireless telephone services called Personal
(MSS)
Communications Satellite System (PCSS)

It uses low earth-orbit (LEO) and medium earth

orbit and MEO thar communicates diretly with
small, low-powered mobile telephone units.
key providers in PCSS market:
 American Mobile Satellite
Communications (AMSC)
 Celsat
Personal Communications
 Comsat
93) Satellite System (PCSS)
 Constellation Communications (ARIES)
 Ellipsat (Ellipso)
 INMARSAT
 LEOSAT
 Loral/qualcomm (global star)
 TMI communications
 TWR (Odysse)
 Iridium LLC

An international consortium owned by a host of

94) prominent companies, agencies and Iridium LC
governments.

The largest commercial venture undertaken in the

95) Iridium Project
history of the world.

A satellite based wireless personal

communications network designed to permit a
Iridium
96) wide range of mobile telephone services,
including voice, data, networking,facsimile and
paging.
97)
FCC issued a report and order Dockett # 92-166 October 14, 1994
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defining L band frequency sharing for subscriber

units in the 1616 MHZ to 1626.5 MHz band.

98) L-band subscriber-to-satellite voice links. 1.616 GHz to 1.6265 GHz

99) Ka-band gateway downlinks.

19.4 GHz to 19.6 GHz
100) Ka-band gateway uplinks
29.1 GHz to 29.3 GHz

101) Ka-intersatellite cross-links 23.18 GHz to 23.38 GHz

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INTRODUCTION TO DATA COMMUNICATIONS

CHAPTER 21 AND NETWORKING

# DEFINITIONS TERMS

Information that is stored in digital form.

1) Information that has been processed, organized and Data
stored.

Information
2) Knowledge or intelligence.

3) The transmission, reception, and processing of digital Data Communications

information.

It is to transfer digital information from one place to Data Communications

4)
another. Circuit

5) A set of devices interconnected by media links. Network

Systems of interrelated computers and computer

Data Communications
6) equipment and can be as simple as a personal
Networks
computer connected together through the PTN

7) Automatic teller machine ATM

When was one of the earliest means of communicating

8) 1753
electrically coded information occurred?

In 1833, he developed an unusual system based on a five-by-

9) five matrix representing 25 letters. The idea Carl Friedrich Gauss
was to send message over a single wire.

The first successful data communications that was

10) Telegraph
invented in 1832. Dots and Dashes

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He invented the first practical data communications

11) Samuel F.B. Morse
code which is called Morse Code.

1. Sir Charles
12) Allegedly invented the first telegraph in England. Wheatstone
2. Sir William Cooke
In 1874, he invented the telegraph multiplexer
which Emile allowed up to six different telegraph machines to
13) be
Emile Baudot
transmitted simultaneously over a single wire.

14) Telephone
It was invented in 1875 by Alexander Graham Bell

15) He succeeded in sending radio telegraph Guglielmo Marconi

messages.

16) The only means of sending information across Telegraph

large spans of water until 1920.

17) A German engineer, demonstrated a computing machine Konrad Zuis

sometime in the late 1930s.

18) J. Presper Eckert

Developed the ENIAC computer on Feb. 14, 1946
John Mauchley

19) A technique that process one job at a time. Batch Processing

20) Built in 1951 by Remington Rand Corp., was the

UNIVAC Computer
First mass-produced electronic computer.

A public data communications network used by

21) Internet
millions of people all over the world to exchange
business and personal information.

Private data communications networks used by

22) Intranet
many companies to exchange information
among employees and resources.

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Any system of computers, computer terminals or

Data Communications
23) computer peripheral equipment used to transmit
Network
and receive information between two or more l
ocations.

A set of equipment, transmission media and procedures

24) that ensures that a specific sequence of events occurs
Network Architecture
in a network in the proper order to produce the
intended results.

25) Messages are intended for all subscribers on the Broadcasting

network.

26) Messages are intended for a specific group of

Multicasting
subscribers.

27) Defines the procedures that the systems involved in the Protocols
communications process will use.

28) Sets of rules governing the orderly exchange of data Data Communications
within the network or a portion of the network. Protocols

29) The list of the protocols used by a system. Protocol Stack

30) Layered Network

It consists of two or more independent levels.
Architecture

31) A logical connection is established between the Connection Oriented

endpoints prior to the transmission of data. or Connectionless

They are designed to provide a high degree of

32) Connection-Oriented
reliability for data moving through the network.
Protocol

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A connection process that occurs between two stations

before any data are actually transmitted.
33) Another terms: Handshake
 Sessions
 Virtual circuits
 logical connections

It refers to the structure or format of the data within the

34) message, which includes the sequence in which the Syntax
data are sent.

Guidelines that have been generally accepted by the

data communications industry. Data Communications
35) Types of standards: Standards
 Proprietary system -open
 open system

36) Generally controlled and manufactured

Proprietary Standard
by one company.

37) The international organization or standardization on a International Standards

wide range of subjects. Organization (ISO)

American National
38) The member of ISO from the United States. Standard
Institute (ANSI)

It is formerly CCITT, one of four permanent parts International

39) is based in Geneva, Switzerland. Telecommunications
Union

40) Modem interfaces and data transmission over the

V series
telephone lines.

41) Data transmission over public digital Network,

X series
e-mail and directory services.

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An international professional organization founded in

Institute of Electrical &
the United States and is comprised
42) IEEE)and Electronics
of electronics, computer and communications
Engineers
engineers.

A non-profit U.S. trade association that establishes and Electronics Industry

43) recommends industrial standards. Association (EIA)

The leading trade association in the communications Telecommunications

44) and information technology industry. Industry Association

45) The research arm of the Department of Defense Advanced Research

in 1957. Projects Agency (ARPA)

A large international community of network designers,

operators, vendors and researches concerned with the Internet Engineering
46) evolution of the internet architecture and the smooth Task Force (IETF)
operation of the internet.

It promotes research of importance to the evolution of

Internet Research Task
47) the future Internet by creating focused, long term and
Force (IRTF)
small research groups working on topics related to
internet protocols.

48) Protocol data Unit

A unit of data.
(PDU)

49) The process of adding and removing the PDU Encapsulation/

information. decapsulation

It means to place in a capsule or other protected

50) Encapsulate
environment.

51) Decapsulate
It means to remove from a capsule or other protected
environment.

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Service Access Point

52) Defines which entity the service is intended. (SAP)

The name for the set of standards for

communicatingamong computers

Seven OSI layers: Open Systems

 application Interconnection
53)  presentation (OSI)
 session
 transport
 network
 data link
 physical

Responsible for the actual propagation of unstructured

54) Physical Layer
data bits through a transmission medium.

Responsible for providing error-free communications

55) across the physical link connecting primary and
Data Link Layer
secondary stations within a network.

Provides details that enable data to be routed between

56) devices in an environment using multiple networks, Network Layer
subnetwork, or both.

Controls and ensures the end-to-end integrity of the

57) data message propagated through the network
Transport Layer
between two devices, which provides reliable,
transparent transfer of data between two endpoints.

58) Responsible for network availability. Session Layer

Provides independence to the application processes by

59) addressing any code or syntax conversion necessary to
Presentation Layer
present the data to the network in a common
communications format.

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60) It provides distributed information services and controls

Application Layer
the sequence of activities within an application.

61) An endpoint where subscribers gain access to Station

the circuit.
Another term of station which is the location of
62) computers, computer terminals, workstations and Node
other digital computing equipment.

63) Interconnects digital computer equipment. Facilities

64) Source
Provides means to enter data from humans.

Encodes a wireless radio system without being

65) Transmitter
converted to analog first.

Carries the encoded signals from the transmitter

66) Transmission
to the receiver.
Medium
Converts the encoded signals received from the
67) Receiver
transmission medium back to their original form.

68) It could be a mainframe computer, personal computer

Destination
workstation or virtually any piece of digital equipment

A type of transmission where all four bits can be Parallel by Bit or

69) transmitted simultaneously during the time of a single Serial by Character
clock pulse.

70) Transmission where four clock pulses are required to

Serial by Bit
transmit the entire four-bit code.

71) Two-Point
It involves only two locations or stations
Configuration

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72) Multi-point
It involves three or more stations.
Configuration

73) Data transmission is unidirectional where information Simplex

can be sent in only one direction.

74) Also called Receive-Only, Transmit Only or One-way- Simplex Lines

only Lines

Data transmission is possible in both directions but not at

the same time.
75) Half Duplex
Another term:
 two way alternate lines
 either way lines

Transmission are possible in both directions

two stations. simultaneously , but they must be between
same
76) Full Duplex
Another terms;
 Two-way simultaneous
 duplex
 both-way lines

Transmission is possible in both directions at the same

77) time but not between the same two stations. It is
Full/Full Duplex
possible only on multipoint circuits.

78) The process of sharing resources between computers Networking

over a data communications network.

79) The manual technique of moving data on disks. Sneaker Net

Computers that hold shared files, programs and the

80) network operating system. Servers

81) Computers that access and use the network and Client
shared network resources.

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82) The facilities used to interconnect computers in a Transmission Media

network.

83) Data that file servers provide to clients. Shared Data

Shared Printers and

84) Hardware resources provided to the users of the other
network by servers. peripherals

An expansion card and prepares and sends data, Network Interface Card
85) receives data and controls data flow between the (NIC)
computer and the network.

Allows personal computers to access files, print to a Local Operating System

86) local printer and have and use one or more disk and (LOS)
CD drives that are located on the computer.

A program that runs on computers and servers that Network Operating

87) allows the computers to communicate over a network. System (NOS)

88) Peer - to - Peer Client/

One in which all computers share their resources.
Server Network

One computer is designated the server and the rest of Dedicated

90) the computers are clients. Client/Server
Network

91) Describes the layout or appearance of a network. Network Topology

92) Describes how the network is actually laid out Physical Topology

93) Describes how data actually flow through the network

Logical Topology

A multipoint data communications network where

94) Star Topology
remote stations are connected by cable segments
directly to a central located computer.

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A multipoint data communications circuit that makes it

95) relatively simple to control data flow between and Bus Topology
among the computers.

A multipoint data communications network where all

96) stations are interconnected in tandem to form a closed Ring Topology
loop or circle.

97) Every station has a direct two-point communications

Mesh Topology
linkto every other station on the circuit.

98) Combining two or more of the traditional topologies to Hybrid Topology

form a larger, more complex topology.

Local Area Networks

99) Privately own networks in which 10 to 40 compute share
(LANs)
data resources with one or more file server.

A high-speed network similar to a LAN except the are Metropolitan Area

100) designed to encompass larger areas, usually that of Networks (MANs)
an entire city.

Provides low-speed, long distance transmission of data

Wide Area Network
101) voice, and video information over large and widely WAN)
dispersed geographical areas such as country or an
entire continent. It interconnects cities or states.

102) Bit rate of WANs. 1.5 Mbps-2.4 Gbps

Global Area Network

103) Provides connects between countries around the entire
(GANs)
globe.

104) A network connection that normally carries traffic Building Backbone

between departmental LANs within a single company.

105) A network connection used to carry traffic to and from Campus Backbone
LANs located in various buildings on campus.
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Developed by Department of Defense, comprise of

106) TCP/IP Protocol Suite
several interactive modules that provide specific
functionality.

107) Internet layer/

The network layer of TCP/IP.
Internet work Layer
Transmission Control
(UDP)
108) Transport layer of TCP/IP. User datagram Protocol
Protocol (TCP)

109) Provides a means of physically delivering data

Network Access Layer
packets using frames or cells.

110) Contains information that pertains to how data Internet Layer

can be routed through the network.

111) Services the process and internet layers to handle the

Host-to-Host Layer
reliability and session aspects of data transmission.

112) Provides applications support.

Process Layer

Defines a three layer logical hierarchy that specifies

where things belong, how they fit together and what
functions go where.
Cisco Three-Layer
113) Model
Three layers:
 Core layer
 Distribution layer
 access layer

114) The core of the network as it resides at the top of the

Core Layer
hierarchy and is responsible for transporting large
amounts of data traffic reliably and quickly.

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The communications point between the access and

115) the core layers that provides routing , filtering, WAN Distribution Layer
access and how data packets are allowed to access
the core layer.

116) Another term for Distribution layer Workgroup Layer

117) Controls workgroup and individual user access to Access Layer

internetworking resources.

118) Another term for Access layer. Desktop Layer

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FUNDAMENTAL CONCEPTS OF DATA

CHAPTER 22 COMMUNICATIONS

# DEFINITIONS TERMS

Often used to represent characters and symbols

such as letters, digits and punctuation marks.
Another terms: Data Communications
1)  character codes Codes
 character sets
 symbol codes
 character languages

Sometimes called the Telex Code, was the first fixed

2) length character developed for machines rather Baudot Code
than forpeople.

A French postal engineer who developed the

3) baudot code in 1875 and named after Emile Baudot, Thomas Murray
an early pioneer in telegraph printing.

4) Fixed-length source code. Fixed Length Block Code

Stands for United States of America Standard Code USASCII

5)
for Information Exchange, better known as ASCII-63.

The standard character set for source coding the

alphanumeric character set that humans understand
6) but computers do not (computers only understand 1s ASCII
and 0s).
It is a seven bit fixed-length character set.

7) Fixed-length source code. Fixed Length Block Code

Extended binary coded decimal interchange-code, EBCDIC

8)
an eight bit fixed length character developed in
1962 by International Business Machines Corporation.

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Omnipresent block and white striped stickers that

seem to appear or virtually every consumer item in
9) Bar Codes
the US and most of the rest of the world.

It has spaces or gaps between characters. Each

10) character is independent of every other character. Discrete Code

It does not include spaces between characters. An

11) Continuous Code
example is Universal Product Code.

It stores data in two dimensions in contrasts with

12) conventional linear bar codes which stores data 2D code
along only one axis.

It uses an alphanumeric code similar to ASCII code. It

contains 9 vertical elements (5 bars & 4 spaces). It
consists of 36 unique codes representing the 10 digits
and 26 uppercase letters.
13) Code-39
Other Names:
 Code 3 of 9
 3 of 9 code

A continuous code since there are no

14) interchangeable spaces. Each UPC label contains a Universal Product Code
12-digit number.

Start & Stop Guard

It consists of a 101 (bar-soace-bar) sequence, which
15) Pattern
is used to frame the 12 digit UPC number.

It separates the left and right halves of the label and Center Guard Frame
16)
consists of two long bars in the center of the label.

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Caused by electrical interference from natural

sources
Classification of Data Com Errors:
 single bit
 multiple bit Transmission Errors
17)  burst

Categories of Error Control :

 Error Detection
 Error Correction

Errors with only one bit within a given a given string is Single Bit Errors
18)
in error.

Errors with two or more non-consecutive bits within a

19) Multiple-bit error
message.

Errors when to or more consecutive bits within a

Burst Error
20) given data string are in error. It can affect one or
more characters within a message.

The theoretical (Mathematical) expectation of the

21) Probability of Error
rate at which errors will occur.

The actual historical record of a system’s error perfor-

22) Bit-Error Rate
mance.

The process of monitoring data transmission and

deter mining when errors have occurred. It neither
23) Error Detection
correct errors nor identify which bits are in error-they
only indicate when an error has occurred.

Adding of bits for the sole purpose of detecting errors

Types of redundancy checks:
24)  vertical redundancy checking, Redundancy Checking
 checksum,
 longitudinal redundancy checking
 cyclic redundancy checking

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A form of error detection by duplicating each data

Redundancy
25) unit for the purpose of detecting errors.

26) An error detection bit. Parity

Vertical Redundancy
27) The simplest error-detection scheme and is generally
Checking (VRC)
28) referred to as character parity.

29) An error detection bit in each character. Parity Bit

30) The parity bit which is always a 1. Marking Parity

31) The parity bit which is not sent or checked Ignored Parity

Form of redundancy error checking where each

Checksum
32 character has a numerical value assigned to it.

Longitudinal
A redundancy error detection scheme that uses
Redundancy Checking
33) parity to determine if a transmission error has
(LRC)
occurred with n a message.

Message Parity
34) An error occurred within a message.
Block or Frame of Data
35) The group pf characters that comprise a message
Block Check Sequence
(BCS) or Frame Check
36) The bit sequence for the LRC. Sequence (FCS)

A convolution coding scheme that is most reliable Cyclic Redundancy

37) redundancy checking technique for error detection. Checking
Almost 99.999% of all transmission errors are detected

Lost Message Damaged

38) Types of Error Messages. Message

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One that never arrives at the destination or one that Lost message
39)
is damaged to the extent that it is unrecognizable.

One that is recognized at the destination but Damaged Message

40)
contains one or more transmission errors.

It includes enough redundant information with each

transmitted message to enable the receiver to
determine hen an error has occurred.

41) Examples: Error-Detecting Codes

 Parity bits
 block and frame check characters
 cyclic redundancy characters

It includes sufficient extraneous information along

with each message to enable the receiver to
determine hen an error has occurred and which bits
is in error.
42) Error-correcting Codes
Two primary methods for error correction:
 Retransmission
 Forward Error Correction

When a receive station requests the transmit station

43) Retransmission
to resend a message when the message is received
in error.

A two-way radio term which automatically a

retransmission f the entire message.
Automatic Repeat
Types of ARQ:
Request (ARQ) or
44) Automatic Retransmission
 Discrete
Request
 Continuous

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The recipient of data sends a short message back to

the sender acknowledging receipt of the last
transmission.
45)
Types of acknowledgements:
 Positive Acknowledgement
 Negative

A receive station becomes the transmits station such

as when acknowledgments are sent or when
46) Line Turnarounds
retransmission are sent in response to a negative
acknowledgment.

It uses acknowledgments to indicate the successful Discrete ARQ

47)
or unsuccessful reception of data.

It can be used when messages are divided into

smaller lock or frames that are sequentially Continuous ARQ
48)
numbered and transmitted in succession, without
waiting for acknowledgments between blocks.

The sending station does not receive an

Retransmission Time-Out
49) acknowledgment after a predetermined length of
time.

The destination station asynchronously requests the

retransmission of specific frame of data and still be
Selective Repeat
50) able to reconstruct the entire message once all
frames have been successfully transported through
the system.

The error-correction scheme that detects and Forward Error Correction

51) corrects transmission errors when they are received (FEC)
without requiring a retransmission.

A mathematician who was an early pioneer in the

Richard W. Hamming
52) development of error-detection and correction
procedures, developed the Hamming Code while
working at Bell Telephone Laboratories.

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An error-correcting code used for correcting

transmission errors in synchronous data streams. Hamming Code
53)
It requires the addition of overhead to the message,
consequently increasing the length of a transmission.

54) Inserted into a character at random locations. Hamming Bits

The combination of the data bits and the hamming Hamming Code
55)
bits.

56) It means to harmonize, coincide, or agree in time. Synchronize

Involves identifying the beginning and end of a

57) Character Synchronization
character with in a message.

Its literal meaning is “without synchronism”.

Asynchronous
58) In Data Com, it means “without a specific time
reference”

Asynchronous communications is called as such

Start-stop Transmission
59) because each data character is framed between
start and stop bits.

A condition when the transmit and receive clocks Clock Slippage

60)
are substantially different

It occurs when the transmit clock is substantially Under slipping

61)
lower than the receive clock.

Occurs when the transmit clock is substantially higher

62) Overslipping
than the receiver clock.

63) Synchronous Data

It involves transporting serial data at relatively high
speeds in groups pf characters.

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POTS
65) Plain old Telephone system

It is comprised of three basic elements:

transmitter (source)
 transmission path (data channel)
Data Communications
 receiver (destination)
66) System
3 fundamental components of endpoints:
 data terminal equipment
 data communications equipment
 serial interface

It can be virtually any binary digital device that

Data Terminal
generates transmits, receives, or interprets data
67) Equipment (DTE)
messages. It is where information originates or
terminates.

Devices used to input, output and display Terminal

68)
information such as keyboards, printers and monitors

Basically a modern-day terminal with enhance

69) Client
computing capabilities

High-powered, high capacity mainframe computers Hosts

70)
that support terminals.

71) It functions as modern-day host. Servers

A general term use to describe equipment that

interfaces data terminal equipment to a transmission
channel, such as a digital T1 carrier or an analog
telephone circuit. It is a signal conversion device, as
Equipment (DCE)
it converts signals from a DTE to a form more suitable
72) Data Communications
to be transported over transmission channel.

Types of DCE:
 channel service units (CSUs)
 Digital service units (DSUs)
 data modems

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Data Circuit-terminating
73) Another term for DCE.
Equipment (DCTE)

A DCE used to interface a DTE to an analog

74) telephone circuit commonly called POTS. Data Modem

It controls data flow between several terminal

75) Cluster Controller
devices and the data communications channel.

Station Controllers
76) Line control units at secondary stations.
(STACOs)

Universal Asynchronous Receiver/transmitter UART

77)
it is designed for asynchronous data transmission.

Asynchronous
A special purpose UART chip manufactured by
Communications
78) Motorola.
Interface Adapter
(ACIA)

It means that an asynchronous data format is used Asynchronous Data

79) and no clocking information transferred between the Transmission
DTE and the DCE.

An n-bit data register that keeps track of the status of Status Word
80)
the UART’s transmits and receive buffer registers.

Transmit Buffer Empty

Transmit shift register has completed transmission
81) (TBMT)
of data character.

82) Receive Parity Error (RPE)

Set when a received character has a parity error in it.

Receive Framing Error an

Set when a character is received without any or with
83) improper number of stop bits.
(RFE)

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Set when a character in the receive buffer register is Receiver Overrun (ROR)
84)
written over by another receive character.

Receive Data Available

A data character has been received and loaded
85) (RDA)
into the receive data register.

The difference in time between the beginning of a Detection Error

86)
start bit and when it is detected.

It is used for synchronous transmission of data

between a DTE and a DCE.
Functions of USRT:
 Serial to parallel and parallel to serial
data conversions
 Error detection by inserting parity bits in
the transmitter and checking parity bits
in the receiver.
 Insert and detect unique data Universal Synchronous
synchronization (SYN) characters Receiver/transmitter
87)
 Formatting data in the transmitter and (USRT)
receiver.
 Provide transmit and receive status
information to the CPU.
 Voltage-level conversion between the
DTE and the serial interface and vice
versa.
 Provide a means of achieving bit and
character synchronization.

It should provide the ff:

 A specific range of voltages for transmit
and receive signal levels
Serial Interface
88)  Limitations for the electrical parameters
of the transmission line.
 Standard cable and cable connectors
 Functional description of each signal
on the interface.
Electronics Industries
In 1962, standardized the interface equipment
89) Association (EIA)
between data terminal equipment and data
communications equipment.

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91) It means “Recommended Standards” RS

Interface Between Data

Terminal Equipment and
Data Communications
92) The official name of the RS-232 interface Equipment Employing
Data Communications
Equipment Employing
Serial Binary Interchange

In, 1969, the third revision which was published and RS-232C
93)
remained the industrial standard until 1987.

Sometimes referred to as the EIZ-232 standard

RS-232D
94) Versions D and E of the RS-232 standard changed
some of the pin designations.

It is a sheath containing 25 wires with a

DB25P-compatible male connector (plug) on one
end and a DB25S-compatible female connector
(receptacle) on the other end.
RS-232 Cable
95)
Two full-duplex channels:
 Primary data-actual information
 secondary data-diagnostic information
and handshaking signals

It is designed for transporting asynchronous data 9-pin Version of RS-232

96)
between a DTE and a DCE or between DTEs .

It is designed for transporting either synchronous or 25 pin Version

97)
asynchronous data between a DTE and a DCE.

It is designed exclusively for dial-up telephone.

It is used for transporting asynchronous data
98) between a DTE and a DCE when the DCE is EIA-561
connected directly to a standard two-wire
telephone line attached to the public switched
telephone network.

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It converts the internal voltage levels from the DTE Voltage-Leveling Circuits
99)
and DCE to RS-232 values.

A voltage leveler wherein its output signals onto the

100) cable. Driver

101) It accepts signals from the cable. Terminator

Protective ground, frame ground, or chassis FUNCTIONS OF RS-232 PINS

102) ground. Pin 1

103) Transmit data or send data. Pin 2

104) Receive data (RD or RxD) Pin 3

105) Request to send (RS or RTS) Pin 4

106) Clear to send.(CS or CTS) Pin 5

107) Data set ready or modem ready.(DSR or MR) Pin 6

108) Signal ground or reference ground. Pin 7

109) Unassigned and non-EIA specified often held at +12V Pin 8

Receive line signal detect, carrier detect or data Pin 9

110)
carrier detect (RLSD, CD or DCD)

Unassigned and often held at -12 Vdc for test

111) Pin 10
purposes

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Secondary receive line signal detect, secondary

Pin 12
112) carrier detect or secondary data carrier detect
(SRLSD, SCD, or SDCD)

Pin 13
113) Secondary clear to send.
Secondary transmit data or secondary send data
114) Pin 14

Transmission signal element timing or serial Clock Pin 15

115)
transmit.

116) Secondary received data Pin 16

117) Receiver signal element timing or serial clock receive

Pin 17

118) Unassigned is used for local loopback signal Pin 18

119) Secondary request to send Pin 19

120) Data terminal ready. Pin 20

121) Signal quality detector. Pin 21

122) Ring indicator (RI) Pin 22

123) Data signal rate selector (DSRS) Pin 23

Transmit signal element timing or serial clock

Pin 24
124) transmit-DTE

Unassigned. It is sometimes used as a control signal

from the DCE to the DTE to indicate that the DCE is in
Pin 25
125) either the remote or local loop back mode.

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It specifies a 37-pin primary connector DB37 and a 9

pin secondary connector DB9 for a total of 46 pins
which provides more functions, faster data
transmission rates and spans greater distances than
the RS-232.

Primary goals of RS-449:

 Compatibility with the RS-232
interface standard
 Replace the set of circuit names and
mnemonics
 Provide separate cables and
126) connectors RS-449 Serial Interface
 Reduce crosstalks
 offer higher data transmission
 longer distances over twisted pair
cables
 loopback capable
 improve performance and reliability
specify a standard connector

Two categories:
 Category I
 Category II

Used by the DTE to request a local loopback from the 10 CIRCUITS IN RS-449
127) DCE.
1.Local Loopback

Used by the DTE to request a remote loopback

128 2.Remote Loopback
from the distant DCE.

Allows the DTE to select the DCE’s transmit and 3. Select frequency
receive frequencies.

Used by DTE to signal the DCE that a test is in

129) 4.Test Mode
progress.

5. Receive Common
130) Common return wire for unbalanced signals
propagating from the DCE to the DTE

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Used by the DTE to signal the DCE whether it is 6. Terminal in Service

131)
operational

Used by the DTE to request that the DCE switched to

132) 7. Select Standby
standby equipment.

Used with a modem at the primary location of a

133) 8. New Signal
multipoint data circuit.

It was intended to operate at data rates between 20

136) RS-530 Serial Interface
kbps and 2 Mbps using the same DB25 connector

It is used to interface computers, computer networks

to analog transmission media
Data Communications
Alternate names:
137) Modem
 datasets
 dataphones
 modems

A contraction derived from the words Modulator

and Demodulator.
Primary Block of a Modem:
 Serial interface Circuit
 Modulator Circuit
138) Modem
 Bandpass filter and equalizer circuit
 telco interface circuit
 demodulator circuit
 carrier and clock generation circuit

Data communications modems designed to operate

139) Voice-band Modem
over the limited bandwidth of the PSTN.

140) It is able of transporting higher bit rates. Broadband Modem

141) Digital to analog converter. DAC

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142) Analog to digital converter. ADC

It is a rate of change of signals on the transmission

Baud
143) medium after encoding and modulation have
occurred

Refers to the rate of change of a digital information Bit Rate

144)
signal.

145) It is classified as low-speed voice-band modems Asynchronous Modems

Synchronous data transported by asynchronous Isochronous Transmission

146)
modems.

It uses PSK or quadrature amplitude modulation Synchronous Modems

147)
to transport data.

A special, internally generated bit pattern in transmit

148) Training Sequence
modem.

Located in the transmit section of a modem and

149) Compromise Equalizers
provide pre-equalization

Located in the receiver section of a modem where

Adaptive Equalizer
150)
they provide post-equalization to the received
signals

The first internationally accepted standard fro ITU-T V.29

151)
9600bps data transmission rate.

It is intended to provide synchronous data

V.29 Standard
152) transmission over four-wire leased lines.

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153) Five bits. Quin bits

A technique for full-duplex operation over two wire

Echo Cancellation
154) switched telephone lines.

It address asynchronous-to synchronous transmission

conversions and error control that includes both
155) V.32 Specification
detection and correction. It specifies a new protocol
called Link Access Procedures for Modems.

It is the next generation data transmission with data

rates of 28.8 Kbps without compression possible using
V.34.

V.34 Innovations:
V.fast
156)  Nonlinear coding
 multidimensional coding and
constellation shaping
 Reduced complexity
 precoding of data
 line probing

An enhanced standard adopted by ITU in 1996.

It adds 31.2 kbps and 33.6 kbps to the V.34
157) V.34+
specification.

Developed by ITU-T in February 1998 during a

meeting in Geneva, Switzerland. It defines an
asymmetrical data transmission technology where
158) V.90 Recommendation
the upstream 33.6kbps and downstream of 56kbps.

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A new modem standard in 2000 which offers

3 improvements over V.90 that can be achieved
only if both the transmit and receive modems and
the internet Service Provider(ISP) are compliant.
159) V.92 Recommendation
It offers:
 upstream transmission rate of 48 kbps
 faster call setup capabilities
 incorporation of a hold option

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DATA-LINK PROTOCOLS AND DATA

CHAPTER 23 COMMUNICATIONS NETWORKS

# DEFINITIONS TERMS

The primary goal of __________ is to give

users of a network the tools necessary for
1) Network Architecture
setting up the network and performing
data flow control.

A set of rules implementing and governing

2) an orderly exchange of data between Data-Link Protocol
two layer devices.

The transmitting station in a data link

3) Master Station
protocol.

The receiving station in a data link

4) Slave Station
protocol.

Data link network wherein all stations have

5) Peer-to Peer Network
equal access to the network.

6) Discipline, Flow Control and Error Control. Functions of Data-link Protocol

Coordinates hop-to-hop data delivery

where a hop may be a computer, a
7) Line Discipline
network controller, or some type of
network-connecting device

Determines which device is transmitting

8) Line Discipline
and which is receiving at any point in
time.

Coordinates the rate which data are

9) transported over a link and generally Flow Control
provides an acknowledgement
mechanism.
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Specifies means of detecting and

10) Error Control
correcting transmission errors.

Two fundamental ways that line discipline Enquiry/Acknowledgement(ENQ/ACK)

11) is accomplished in a data and Poll/Select
communications network.

It determines which device on the

network can initiate a transmission and
12) ENQ/ACK
whether the intended receiver is available
and ready to receive a message.

The initiating station begins a session by

transmitting a frame, block, or packet of
13) Enquiry(ENQ)
data called _________, which identifies the
receiving station.

The response of the destination station

14) Positive Acknowledgement (ACK)
when it is ready to receive.

The response of the destination station

15) Negative Acknowledgement (NAK)
when it is not ready to receive.

The best application of the poll/select line

16) Centrally Controlled Data Network
discipline.

A solicitation sent from the primary to a

17) secondary to determine if the Poll
secondary has data to transmit

A set of procedures that tells the

transmitting station how much data it can
send before it must stop transmitting and
21) Flow Control
wait for an acknowledgment from the
destination station

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The transmitting station sends one

message frame and then waits for an
22) Stop-and Wait Flow Control
acknowledgement before sending the
next message frame.

A source station can transmit several

23) frames in succession before receiving an Sliding Window Flow Control
acknowledgement.

It refers to imaginary receptacles at the

source and destination stations with the
24) Sliding Window
capacity of holding several frames of
data.

Primary advantage of sliding window

25) Network Utilization
control.

Primary disadvantages of sliding window

26) Complexity and Hardware Capacity
flow control.

Interpret a frame of data as a group of

successive bits combined into predefined
27) Character Oriented Protocols
patterns of fixed length, usually eight bits
each.

Another name for character oriented

28) Byte-oriented Protocols
protocols.

A discipline for serial by bit information

29) transfer over a data communications Bit Oriented Protocol
channel.

A character-oriented protocols generally

used on two point networks using
30) Asynchronous Data link Protocols
asynchronous data and asynchronous
modems.

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Developed the first file transfer protocol

31) designed to facilitate transferring data Ward Christiansen
between two personal computers in 1979.

Cristiansen's protocol which is relatively

32) simple data link protocol intended for low- XMODEM
speed applications.

Remote stations can have more than one

33) Synchronous Data-Link Protocols
PC or printer.

A group of computers, printers, and other

34) Cluster
digital devices.

A synchronous character-oriented data Binary Synchronous Communications

35)
link protocol developed by IBM. (BSC)

36) Bisync
Another name for BSC.

Another name for enquiry (ENQ)

37) Format or line turn around
character.

The __________ uses longitudinal

redundancy checking (LRC) with ASCII-
38) Block Check Character (BCC)
coded messages and cyclic redundancy
checking.

A synchronous bit oriented protocol

39) developed in the 1970's by IBM for use in Synchronous Data-Link Control (SDLC)
system network architecture environment.

Three transmission states.

40) Transient, Idle and Active

Flag Fields, Address Field, Control Field,

41) SDLC Frame Fields
Information and Frame Check Sequence
Field are __________.

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It is used for the delimiting sequence for

42) the frame and to achieve frame and Flags
character synchronization.

It is used for polling, confirming previously

received frames, and several other data
43) Control Field
link management functions

Information, Supervisory and

44) Three frame formats with SDLC.
Unnumbered

A command or a response that is used to

45) Unnumbered Information (UI)
send unnumbered information.

A command that places a secondary

46) Set Initialization Mode
station into the initialization mode.

A response sent by a secondary station to

47) request the primary to send a SIM Request Initialization Mode (RIM)
command.

A command that places a secondary into

48) Set Normal Response Mode (SNRM)
the normal response mode.

A response transmitted from a secondary

station if the primary attempts to send
49) numbered information frames to it when Disconnect Mode (DM)
the secondary is in the normal disconnect
mode.

A response sent by a secondary when it

50) wants the primary to place it in the Request Disconnect (RD)
disconnect mode.

An affirmative response that indicates

52) compliance to SIM, SNRM or DISC Unnumbered Acknowledgement
commands

53) An exchange of frames between the TEST

primary station and a secondary station.

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A flag followed by eight consecutive logic

54) Turnaround Sequence
0's.

A SDLC subcommand causes all

55) previously set functions to be cleared by Clear
the secondary.

A SLDC subcommand causes the

56) secondary receiving it to turn on or turn Beacon Test
off its carrier.

A SDLC command causes the addressed

57) Monitor Mode
secondary station to pace itself into the
monitor mode.

A SDLC command causes a secondary

58) station to loop its transmission directly to its Wrap
receiver input.

A SDLC command causes the

59) Self-Test
addressed secondary to initiate a series of
internal diagnostic tests.

The transparency mechanism used with

60) Zero Bit Insertion or Zero Stuffing
SDLC.

It is used prematurely terminate an SDLC

61) Message Abort
frame.

62) The encoding scheme used in SDLC. Invert-On-Zero Coding

Standard that defines the frame structure,

delimiting sequence, transparency
63) ISO 3309
mechanism and error detection method
used with HDLC.

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64) Operational Mode of SDLC. Normal Response Mode (NRM)

A mode of operation logically equivalent

to a two point private line circuit where
65) Asynchronous Balanced Mode
each station has equal data link
responsibilities.

A switched data communications network

similar to the public telephone network
66) Public Switched Data Network (PDN)
except a PDN is designed for transferring
data only.

It is used when making a standard

67) telephone call on the public telephone Circuit Switching
network.

68) Is a form of store and forward network. Message Switching

69) Hold and Forward Network

Another name for packet switching.

A user interface as the international

70) X.25
standard for packet network access.

SA logically equivalent to a two point

71) dedicated private line circuit except Permanent Virtual Circuit (PVC)
slower.

A logically equivalent to making a

telephone call through the DDD network
72) Virtual Call
except no direct end to end connection is
made.

Identifies whether the packet is a new call

73) Format Identifier
request or a previously established call.

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A 12 bit binary number that identifies the

74) source and destination users for a given Logical Channel Identifier
virtual call.

This four bit gives the number of digits that

75) Calling Address Field
appear in the calling address filed.

This field is the same as the calling address

field except that it identifies the number of
76) Called Address Length
digits that appear in the called address
field

77) This field contains the destination address. Called Address

This field is the same as the called address

78) Calling Address
field except that it contains up to 15 BCD.

79) This field identifies the number of eight bit Facilities Length Field
octets present in the facilities field.

This 32 bit field is reserved for the

80) Protocol Identifier
subscriber to insert user level protocol.

A proposed network designed by the

Integrated Services Digital Network
81) major telephone companies in
(ISDN)
conjunction with the ITU-T.

Customers gain access to the ISDN system

82) through a local interface connected to a Digital Pipe
digital transmission medium.

ISDN objectives that ensure universal

83) System Standardization
access to the network.

Said objectives that allow customers to

84) use a variety of protocols and Achieving Transparency
applications

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ISDN should not provide services that

85) Separating Functions
preclude competitiveness

Provide private-line and switched services

86) Variety of Configurations
refers what objectives of ISDN.

ISDN services should not be directly

87) related to cost and independent of the Addressing Cost-Related Tariffs
nature of the data.

88) Provide a smooth transition while evolving. Migration

Provide service to low capacity personal

89) Multiplexed Support
subscribers as well as to large companies.

Translation between non-ISDN data

90) protocol and ISDN is performed in this Terminal Adapter
device.

A boundary to the network and may be

91) Network Termination 1
controlled by the ISDN provider.

Refers to interfaces between the common

92) carrier subscriber loop and the central U-Reference Point
office switch

The media interface point between an

93) U Loop
NT1 and the central office.

It is defined by ITU-T as a service that

provides transmission channels capable of
94) Broadband ISDN
supporting transmission rates greater than
the primary data rate.

Information transfer is primarily from

95) Distribution Services
service provider to subscriber

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Codes the data information into smaller

96) Broadband Node
packets used by the BISDN network

A connection between a source and a

97) Virtual Channel
destination, which may entail several ATM
links.

Once data have entered the ATM

98) Cells
network, they transferred into fixed time
slots called ________.

Controls the flow of traffic across the user

99) Generic Flow Control Field (GFC)
network interface (UNI) and into the
network.

The first three bits of the second half of

100) Payload Type Identifier
byte 4 specify the type of message in cell.

Information fields that are designed to

accommodate PCM-TDM traffic, which
101) Constant Bit Rate
allows the ATM network to emulate voice
or DSN services.

A portion of a public service provider's

switching system where the service
102) Public ATM Switches
provider could be a local telephone
company or a long-distance carrier.

Provides the most effective and

103) economical means of handling local data Local Area Networks (LAN)
communications field.

A communications system that allows

104) users to send messages to each other E-Mails
through their computers.

105) LAN Topologies. Star, Bus and Ring Topology

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It describes how users access the

106) Network Access Methodologies
communications channel in a LAN.

Access method used primarily in bus

107) CDMA/CD
topology.

It two stations transmit at the same time,

108) Collision
________ occurs.

The time it takes a signal to travel from a

109) Propagation Delay
source to a destination.

A base band transmission system

110) designed in 1972 by Robert Metcalfe and Ethernet
David Boggs.

Its purpose is to establish clock

111) Preamble
synchronization.

It is simply a series of two logic 1's

112) Start Frame Delimiter
appended to the end of the preamble.

Consists of six bytes the corresponds to the

113) Source Address
address of the station sending the frame.

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MICROWAVE RADIO COMMUNICATIONS AND

CHAPTER 24 SYSTEM GAIN

# DEFINITIONS TERMS

Electromagnetic waves with frequencies that range Microwaves

1)
from approximately 500 MHz to 300 GHz or more.

The wavelengths for microwave frequencies, which is 1 cm and 60 cm slightly

2)
than infrared energy. longer

The name given to microwave signals, because of their “Microwave” waves

3)
inherently high frequencies, have short wavelengths.

Each frequency is divided in half with the lower half

Full-Duplex (Two-way)
4) identified as the low band and the upper half as
narrow band.

Communications system used to carry information for

Short Haul
5) relatively short distances such as between cities with
the same state.

Microwave systems that is used to carry information for

Long Haul
6) relatively long distances, such as interstate and
backbone route applications.

It propagate signals through Earth’s

atmosphere between transmitters and receivers often
located on top of tower spaced about 15 miles to 30
miles apart.

Advantages of Microwave Radio: Microwave Radios

7)
 Radio systems do not require a right-of
way acquisition between

stations.
 Each station requires the purchase or
lease ofonly a small area of land.
 Because of their high operating
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frequencies, microwave radio systems

can carry large quantities of information.
 High frequencies mean short
wavelengths, which require relatively
small antennas.
 Radio signals are more easily propagated
around physical obstacles such as water
and high mountains
 Fewer repeaters are necessary for
amplification.
 Distances between switching centers are
less.
 Underground facilities are minimized.
 Minimum delays are introduced.
 Minimal crosstalk exists between voice
channels.
 Increased reliability and less
maintenance are important factors.

Disadvantages of Microwave Radio:

 It is more difficult to analyze and design
circuits at microwave frequencies.
 Measuring techniques are more difficult
to perfect
and implement at microwave
frequencies.
 It is difficult to implement conventional
circuit components at microwave
frequencies.
 Transient time is more critical at
microwave frequencies.
 It is often necessary to use specialized
components for microwave frequencies.
 Microwave frequencies propagate in a
straight line, which limits their use to line-
of-sight applications.

Propagates signals outside the Earth’s atmosphere and

Satellite Systems
8) are capable of carrying signals much farther while
utilizing fewer transmitters and receivers.

It is used in microwave radio systems rather than

Frequency Modulation
9) amplitude modulation because AM signals are more
sensitive to amplitude nonlinearities inherent in wide-
band microwave amplifiers.

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Major factor when designing FM Radio systems. It is

caused by repeater amplitude nonlinearity in AM, Intermodulation Noise
10)
while in FM, it is caused by transmission gain and delay
distortion.

The composite signal that modulates the FM carrier

and may comprise one or more of the following:

 Frequency-division multiplexed voice-

band channels Baseband
11)
 Time-division-multiplexed voice-band
channels
 Broadcast-quality composite video or
picture phone
 Wideband data

It provides an artificial boost in amplitude to the higher

Preemphasis Network
12) baseband frequencies.

Frequency modulation index used in the FM deviator.

Low-Index
13) Typically, modulation indices are kept between 0.5 and
1.

FM signal that is produces at the output of the deviator Narrowband FM

14)
with a low-index frequency modulation.

A receiver and a transmitter placed back to back or in

15) Microwave Repeaters
tandem with the system.

It receives a signal, amplifies and reshapes it, and then

retransmit the signal to the next repeater or terminal
station down line from it.
Types of Microwave repeaters:
16)  IF Repeater Station
 Baseband
 RF

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The received RF carrier is down-converted to an IF

IF Repeater
17) frequency, amplified, reshaped, up-converted to an RF
frequency, and then retransmitted.

Baseband Frequencies
18) Generally less than 9 MHz.
IF frequencies
19) The range id 60 MHz to 80MHz.

Another name for a Local oscillator, is considerably

lower in frequency than either the received or the Shift Oscillator
20)
transmitted radio frequencies.

Transmission used by microwave systems wherein a

21) direct signal path must exist between the transmit Line-of Site Transmission
receive antennas.

A temporary reduction in signal strength which last in Radio Fade

22)
milliseconds for several hours or even days.

It suggests that there is more than one transmission

Diversity
23) path or method of transmission available a transmitter
and a receiver.

It is simply modulating two different RF carrier

Frequency Diversity
24) frequencies with the same IF intelligence, then
transmitting both RF signals to a given destination.

The output of a transmitter is fed to two or more

Space Diversity
25) antennas that are physically separated by an
appreciable number of wavelengths.

A single RF carrier is propagated with two different

electromagnetic polarizations. It is generally used in
Polarization Diversity
26) conjunction with space diversity.

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It is more than one receiver for a single radio-frequency

channel. With frequency diversity, it is necessary to also Receiver Diversity
27)
use receiver diversity because each transmitted
frequency requires its own receiver

Another form of Hybrid diversity and undoubtly

provides the most reliable transmission but most
28) Quad Diversity
expensive. It combines frequency, space, polarization
and receiver diversity into one system.

A specialized form of diversity that consist of a

standard frequency diversity path where the two
transmitter/ receiver pairs at one end of the path are Hybrid Diversity
29)
separated from each other and connected to different
antennas that are vertically separated as in space
diversity.

Alternate facilities temporarily made to avoid a service

interruption during periods of deep fades or equipment
failures.
Protection Switching
29) Arrangement
types of protection switching arrangements:
 hotstandby
 diversity

Each working radio channel has a dedicated backup

30) Hot Standby Protection
or spare channel.

A single backup channel is made available to as many Diversity Protection

31)
as 11 working channels.

In hotstandby protection, it splits the signal power and

Head-End Bridge
32) directs it to the working and the spare (standby)
microwave channels simultaneously.

Diversity Protection
33) It has two working channels, one spare
channel, and an auxiliary channel.

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A low-capacity low-power microwave radio that is Auxilliary Channel

34)
designed to be used for a maintenance channel only.

Reliability Objectives
It is where the number of repeater stations between
35) of the Systems
protection switches depends.

Points in the system where baseband signals either

originate or terminate.
four major sections:
36)  baseband Terminal Stations
 wireline entrance link (WLEL)
 FM-IF
 RF sections

Points in a system where baseband signals may be

Repeater Stations
37) reconfigured or where RF carriers are simply
“repeated” or amplified.

Stands for WireLine Entrance Link, it serves as the

WLEL
38) interface between the multiplex terminal equipment
and the FM_IF equipment.

A balanced modulator that, when used in conjunction

with a microwave generator, power amplifier, and
Transmod
39) band-pass filter, up-converts the IF carrier to an RF
carrier and amplifies the RF to the desired output
power.

It must be capable of amplifying very high frequencies

and passing very wide bandwidth signals for
microwave radios.

devices used in microwaveamplifiers:

Power Amplifiers
40)  Klystron Tubes
 Traveling-wave tubes (TWTs)
 IMPATT (Impact avalanche and transit
time)

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It provides the RF carrier input to the up-converter. It is

called as microwave generator rather than an Microwave Generator
41)
oscillator because it is difficult to construct a stable
circuit that will oscillate in the gigahertz range.

It operates in the range 5 MHz to 25 MHz, used to Crystal-controlled

42) provide a base frequency that is multiplied up to the Oscillator
desired RF carrier frequency.

A unidirectional device often made from ferrite

material. It used in conjunction with a channel-
Isolator
43) combining network to prevent the output of one
transmitter from interfering with the output of another
transmitter.

Stands for Automatic Gain Control, is a circuit in an AGC

44)
IF amplifier.

It occurs only when three stations are placed in a

45) Multi-hop Interference
geographical straight line in the system.

It prevents the power that “leaks” out the back and High/Low-Frequency
46) sides of a transmit antenna from interfering with the Scheme
signal entering the input of a nearby receive antenna.

The signal entering the input of a nearby receive Ring around

47)
antenna.

It means that this channels are propagated with V Channels

48)
vertical polarization.

The line-of-sight directly between the transmit and Free-Space Path

49)
receive antenna. Also called as the Direct Wave.

Surface Wave
50) It consists of the electric and magnetic fields
associated with the currents induced in earth’s surface.

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The portion of the transmit signal that is reflected off

51) Earth’s surface and captured by the receive Ground-Reflected Wave
antenna.

The portion of the transmit signal that is returned back

Sky Wave
52) to Earth’s surface by the ionized layers of earth’s
atmosphere.

The loss incurred by an electromagnetic wave as it

Free-Space Path Loss
53) propagates in a straight line through a vacuum with no
absorption or reflection of energy from nearby objects.

A phenomenon wherein electromagnetic energy is

Spreading Loss
54) spread out as it propagates away from the source
resulting in lower relative power densities.

The reduction in signal strength at the

Fading
55)
input to a receiver.

The difference between the nominal output power of a

transmitter and the minimum input power to a receiver System Gain
56)
necessary to achieve satisfactory performance.

Sometimes called as Link Margin, is essentially a “fudge

Factor” included in system gain equations that
Fade Margin
57) considers the non ideal and less predictable
characteristics of radio wave propagation and terrain
sensitivity.

He described ways of calculating outage time due to

fading on a non diversity path as a function of terrain, W.T. Barnett
58)
climate, path length, and fade margin, in April 1969.

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From Bell Laboratories, he derived formulas for

calculating the effective improvement achievable by Arvids Vignant
59)
vertical space diversity as a function of the spacing
distance, path length, and frequency in June 1970.

Carrier-to-Noise
The ratio of the wideband “carrier” to the wideband
60) Ratio (C/N)
noise power.

Also called Receiver Sensitivity, is the minimum wide

Receiver Threshold
61) band carrier power at the input to a receiver that will
provide a usable baseband output.

Pre-detection Signal to-

62) Noise Ratio
The carrier-to-noise ratio before the FM demodulator.

Postdetection Signal-
63)
The carrier-to-noise ratio after the FM demodulator. to-Noise Ratio

A ratio of input signal-to-noise ratio to output signal to Noise Factor (F)

64)
noise ratio.

The noise factor stated in dB and is a parameter Noise Figure

65)
commonly used to indicate the quality of a receiver.

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CHAPTER 25 SATELLITE COMMUNICATIONS

# DEFINITIONS TERMS

Satellite
1) A celestial body that orbits around a planet.

Man-made satellites that orbit earth, providing a

multitude of communication functions to a wide Communications
2) variety of consumers, including military, Satellites
governmental, private and commercial subscriber.

A satellite radio repeater which a satellite may have

many.

Consists of :
3) Transponder
input Bandlimiting device (BPF)
input low-noise amplifier (LNA)
frequency translator
low level amplifier
output bandpass filter

It consists of one or more satellite space vehicles, a

ground-based station to control the operation of the
system, and a user network of earth stations that
4) Satellite System
provides the interface facilities for the transmission
and reception of terrestrial communications traffic
through the satellite system.

It includes control mechanism that support the Bus

5) payload operation.

The actual user information conveyed through the

system. Payload
6)

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A type of satellite wherein it simply “bounces” signals

7) Passive Reflector
from one place to another.

A natural satellite of Earth, visible by reflection of Moon

8)
sunlight having a slightly elliptical orbit.

Radio Beacon
Used by passive satellites for tracking and ranging
9) Transmitters
purposes.

Launched by Russia, the first active earth satellite

10) in 1957. It transmitted telemetry for 21 days. Sputnik I

A type of satellite capable of receiving, amplifying,

Active Satellite
11) reshaping, regenerating and retransmitting
information.

Satellite launched by U.S., it transmitted telemetry

12) Explorer I
information for nearly five months.

Satellite launched by NASA in 1958, a 150-pound

conical-shaped satellite. It was the first artificial Score
13)
satellite used for relaying terrestrial communications.

The first active satellite to simultaneously receive and Telstar I

14)
transmit radio signals.

Launched in 1963, and was used for telephone

television, facsimile and data transmission and Telstar II
15)
accomplished the first successful transatlantic
video transmission.

Launched in February 1963, was the first attempt to Syncom I

16)
place a geosynchronous satellite into orbit.

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It was the first commercial telecommunications

satellite. It launched from Cape Kennedy in 1965 and
Intelsat I
17) used two transponders. Also called as Early Birds.It
stands for International Telecommunications Sate-
llite.

Domestic satellite launched by former Soviet Union in Molya

18)
1966. It means “lighting”.

A German astronomer who discovered the laws Johannes Kepler

19)
thatgoverns satellite motion.

It may be simply stated as:

The planets move in ellipses with the sun at one

focus

The line joining the sun and the planet sweeps

Kepler’s Law
20) out equal intervals of time.

The square of the time of revolution of a planet

divided by the cube of its mean distance from
the sun gives a number that is the same for all
planets.

21) The point in an orbit closest to earth Perigee

Apogee
22) The point in an orbit farthest from the earth.

It states that the square of the periodic time

Harmonic Law
23) of orbit is proportional to the cube of the mean
distance between the primary and the satellite.

High-altitude earth-orbit satellites operating primarily

24) in the 2-GHz to 18 GHz frequency spectrum with orbits Geosynchronous
Satellite 22,300 miles above earth’s surface. Satellite

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Advantages of Geosynchronous Satellite:

It remain almost stationary in respect to a

given earth station.

Available to earth within their shadows

100% of the time.

No need to switch from one geosynchronous

satellite to another as they orbit overhead

The effects of Doppler shift are negligible

Disadvantages of geosynchronous Satellite:

It requires sophisticated and heavy propulsion

device onboard to keep them in a fixed orbit

Much longer propagation delays

Requires higher transmit power and more

sensitive receivers because of the longer
distances and greater path loss.

High precision spacemanship is required.

The angle between the earth’s equatorial plane and

the orbital plane of a satellite measured counter
25) clockwise at the point in the orbit where it crosses the Angle of Inclination
equatorial plane traveling from south to north called
the ascending node.

The point where the polar or inclines orbit

26) crosses the equatorial plane travelling from north to Descending Node
south

The line joining the ascending and descending node

27) Line of Nodes

It is when the satellite rotates in an orbit directl

Equatorial Orbit
28) above the equator, usually in a circular path.

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It is when the satellite rotates in path that takes over

the North and the South poles in an orbit that is close Polar Orbit
29)
to earth and passes over and very close to both the
North and South Poles.

The noise power normalized to a 1 Hz bandwidth, or Noise Density

30)
the noise power present in a 1Hz bandwidth

It identifies the system parameters and is used to

determine the projected carrier-to-noise ratio and
energy Bit-to-noise density ratio at both the satellite
31) Link Budget
and earth station receivers for a given modulation
scheme.

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