Preface:

The purpose of this report is to provide knowledge and information about the
management and equipments used in NTC Pakistan.
The focus of this program is on the opportunities and resources (computer,
telecommunication, networks, software, data and people) that organiation uses.
NTC provide the qualit! of work and connectivit! to ever! subscriber equall!.
Acknowledgement:
"ur special thanks to NTC #!d department to provide us the useful and
valuable information. The NTC provides a reall! good service to the interns.
The emplo!ees of both sections (Transmission and $witching) are responsible
and hard working. %e are ver! much thankful to &'()s of both the sections, (ngg*
&li +uhammad and (ngg* %ahab to provide us a ver! friendl! environment and to
teach us from the basic of the s!stem up to the peak of the new technolog!.
The teachings contain the core information about the transmission process of
the NTC , that how the data is transmitted on the media and Switching, in which
we got the full information of that how a call is connected through the far awa!
distances and to other providers. ,t also contains man! other e-periences like
working in an o.ce environment, facing the real problems, troubleshooting the
equipments and man! more.
%e are ver! much thankful again to all the sta/ of the NTC and the NTC
Corporation.
NATIONAL TELECOMMUNICATION CORPORATION (NTC):
NTC is a government based Telecommunication Service provider Company in Pakistan. NTC
provides Telecommunication Services to government organizations and their employees.
HISTORY OF NTC:
NTC was formed in 1! by a Telecommunication "eorganization
act through which Pakistan Telecommunication Company #PTC$ was split into two Companies
NTC and PTC%. The main ob&ective was to have an infrastructure independent of all other
operators that can be used for the purpose of government communication and as an alternative
support for the operators entering the market.
ORGANIZATIONAL HIRARCHI OF NTC:
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Transmission
RECTIFIER:
There is a Siemens "ectifier S'( )* in NTC which is used to convert
alternating current #+C$, which periodically reverses direction, to direct current #-C pulsating$,
which is in only one direction. The "ectifier provides the ). volts to the system and provides
remaining volts to the batteries to charge them. /n the case of failing of electricity rectifier will
use the batteries as a power source.
There is 0 phase line power supply connected in rectifier. The rectifier provided 1* amp current
and 20.0 voltages to the system. There are two rectifiers uses, another for backup in case of
faulty of one.
POWER IN NTC:
There are two alternative sources of power which are further used to
provide the backup power to the system in case of failing of electricity provided by the 3(SC4.
15 6enerator
15 7atteries
BATTERY ROOM:
/n the 7attery "oom there are two sets of batteries connected in series, each
battery set contains 1) battery cells, each cell of 1 volts, to provides 8). volts to the system.
The Telecommunications e9uipment is operated on -C power #typically 8). volts$. -uring
normal operation when utility power is available, the telecommunications #load$ e9uipment is
operated from the -C power supplied from the rectifiers, which also serve to maintain full
charge on the battery systems. /n the event of a utility failure, the load is supported from the
battery until an emergency power source can be applied, such as a generator.
The main purpose of using two battery sets is that if one set is getting faulty, then we have
another set for backup use.
GENERATOR:
+n electric generator is a device that converts mechanical energy into
electrical energy. /t is used to provide electricity in case of electricity unavailable from 3(SC4.
Transmission
Transmission #in telecommunications$ is the process of sending, propagating and receiving an
analogue or digital information signal over a physical point8to8point or point8to8multipoint
transmission medium, either wired, optical fiber or wireless. Transmission technologies and
schemes typically refer to physical layer protocol duties such as modulation, demodulation, line
coding, e9ualization, error control, bit synchronization and multiple:ing, but the term may also
involve higher8layer protocol duties, for e:ample, digitizing an analog message signal, and
source coding #compression$.
Transmission of a digital message, or of a digitized analog signal, is known as data transmission
or digital communication.
T!"s O# Transmission
There are two types of transmissions5
1. Non8Physical Transmission.
1. Physical Transmission.
Non-Physical Transmission:
This t!pe of transmission is a t!pe of microwave transmission because it
deals with the frequencies (number of c!cles per seconds).
Microwave Frequency:
+icrowave frequenc! refers to an! frequenc! value within the
electromagnetic spectrum that is suitable for microwave data transmission.
+icrowave radio frequencies provide for the transport of all of !our important
microwave data.
Microwave Frequency sed for Telecom !ata Transmission
;icrowave fre9uencies are often used by telecommunications service providers to transmit
microwave data. Though microwave fre9uency technology has become less popular due to
advancement of cellular, satelite, and fiber transmission technologies, microwave e9uipment is
often deployed as a cost8effective alternative to fiber at very remote sites.
"hy use microwave frequencies#
atmospheric attenuation is low at microwave
frequencies,particularl! 45461#,apart from resonances due
to o-!gen and water molecules.
microwave signals will penetrate cloud and fog,in contrast to
visible radiation.
microwaves can continuousl! monitor ploar regions and
tropical forests that are often in darkness or covered in
clouds.
fairl! narrow beams can be obtained with resonabl! sied
antennas to give acceptable resolution.
$adio "aves:
0adio waves are a t!pe of electromagnetic radiation with
wavelengths in the electromagnetic spectrum longer than infrared
light. 3ike all other electromagnetic waves, the! travel at the
speed of light. Naturall!5occurring radio waves are made b!
lightning, or b! astronomical ob7ects. &rti8ciall!5generated radio
waves are used for 8-ed and mobile radio communication,
broadcasting, radar and other navigation s!stems, satellite
communication, computer networks and innumerable other
applications.
'i/erent frequencies of radio waves have di/erent
propagation characteristics in the (arth9s atmosphere: long waves
ma! cover a part of the (arth ver! consistentl!, shorter waves
can re;ect o/ the ionosphere and travel around the world, and
much shorter wavelengths bend or re;ect ver! little and travel on
a line of sight.
Frequency S%ectrum &f $adio "aves
Frequency !esignatio
n
A''reviatio
n
< 5 <6 # (-tremel! low
frequenc!
(3=
<6 5 <66 # $uper low
frequenc!
$3=
<66 5 <666 # >ltra low
frequenc!
>3=
< 5 <6 k# 2er! low
frequenc!
23=
<6 5 <66 k# 3ow frequenc! 3=
<66 k# 5 < +# +edium
frequenc!
+=
< 5 <6 +# #igh frequenc! #=
<6 5 <66 +# 2er! high
frequenc!
2#=
<66 +# 5 <
1#
>ltra high
frequenc!
>#=
< 5 <6 1# $uper high
frequenc!
$#=
<6 5 <66 1# (-tremel! high
frequenc!
(#=
Mo$%&a'ion
/n electronics, mo$%&a'ion is the process of varying one or more properties of a high8
fre9uency periodic waveform, called the carrier signal, with a modulating signal which typically
contains information to be transmitted. This is done in a similar fashion to a musician modulating
a tone #a periodic waveform$ from a musical instrument by varying its volume, timing and pitch.
The three key parameters of a periodic waveform are its amplitude #<volume<$, its phase
#<timing<$ and its fre9uency #<pitch<$. +ny of these properties can be modified in accordance
with a low fre9uency signal to obtain the modulated signal. Typically a high8fre9uency sinusoid
waveform is used as carrier signal, but a s9uare wave pulse train may also be used.
/n telecommunications, modulation is the process of conveying a message signal, for
e:ample a digital bit stream or an analog audio signal, inside another signal that can be
physically transmitted. ;odulation of a sine waveform is used to transform a baseband message
signal into a passband signal, for e:ample low8fre9uency audio signal into a radio8fre9uency
signal #"= signal$. /n radio communications, cable T' systems or the public switched telephone
network for instance, electrical signals can only be transferred over a limited passband fre9uency
spectrum, with specific #non8zero$ lower and upper cutoff fre9uencies. ;odulating a sine8wave
carrier makes it possible to keep the fre9uency content of the transferred signal as close as
possible to the centre fre9uency #typically the carrier fre9uency$ of the passband.
+ device that performs modulation is known as a modulator and a device that performs
the inverse operation of modulation is known as a demodulator #sometimes detector or demod$.
+ device that can do both operations is a modem #modulator>demodulator$.
T!"s o# Mo$%&a'ion
There are many ways to modulate a signal5
+mplitude ;odulation
=re9uency ;odulation
Phase ;odulation
Pulse ;odulation
1. Amplitude Modulation (AM)
+mplitude ;odulation occurs when a voice signal?s varying voltage is applied to a carrier
fre9uency. The carrier fre9uency?s amplitude changes in accordance with the modulated voice
signal, while the carrier?s fre9uency does not change.
@hen combined the resultant +; signal consists of the carrier fre9uency, plus APP(" and
%4@(" sidebands. This is known as -ouble Sideband 8 +mplitude ;odulation #-S78+;$, or
more commonly referred to as plain +;.
2. Frequency Modulation (FM)
=re9uency ;odulation occurs when a carrier?s C(NT(" fre9uency is changed based upon the
input signal?s amplitude. Anlike +mplitude ;odulation, the carrier signal?s amplitude is
ANC3+N6(-. This makes =; modulation more immune to noise than +; and improves the
overall signal8to8noise ratio of the communications system. Power output is also constant,
differing from the varying +; power output.
The amount of analog bandwidth necessary to transmit a =; signal is greater than the amount
necessary for +;, a limiting constraint for some systems.
3. Phase Modulation
Phase ;odulation is similar to =re9uency ;odulation. /nstead of the fre9uency of the carrier
wave changing, the P3+S( of the carrier changes.
+s you might imagine, this type of modulation is easily adaptable to data modulation
applications.
4. Pulse Modulation (PM)
@ith Pulse ;odulation, a <snapshot< #sample$ of the waveform is taken at regular intervals.
There are a variety of Pulse ;odulation schemes5
Pulse +mplitude ;odulation
Pulse Code ;odulation
Pulse =re9uency ;odulation

(RS ( -igital "adio System ):

/t is a system which we seen in the section of non8 physical transmission .
7%4CB -+/6"+; 4= T"+NS;TT/N6 /N -"S
E)CHANGE PCM SRAL TRANSMITTER ANTENA
7%4CB -+/6"+; 4= "(C/'/N6 /N -"S
ANT(NA $()*+($ S$A, P)M (-).AN/(
Pulse Code Modulation (PCM)
/n Pulse Code ;odulation, P+; samples #collected at regular intervals$ are 9uantized. That is to
say, the amplitude of the P+; pulse is assigned a digital value #number$. This number is
transmitted to a receiver that decodes the digital value and outputs the appropriate analog pulse.
The fidelity of this modulation scheme depends upon the number of bits used to represent the
amplitude. The fre9uency range that can be represented through PC; modulation depends upon
the sample rate. To prevent a condition known as <aliasing<, the sample rate ;AST 7( +T
%(+ST twice that of the highest supported fre9uency. =or typical voice channels #) Bhz
fre9uency range$, the sample rate is . B3z.
SRAL
@ord S"+% stand for small capacity "adio +ccess %ink. 6enerally this device used for
transportation of (1 from point + to point 7. This system provides point to point communication
in C to . 63D =re9 band. ;a& parts of S"+% system are as under.
a. Power $uppl! >nit ($2(5?4@)
b. ,'> (,n 'oor >nit)
c. "'> ("ut 'oor >nit)
d. .A +tr 'ish
e. =eeder Cable (with connecters)
T(). !ATA
Tra.c Capacit!*
a. @B@ +CDs
b. EB@ +CDs
c. FB@ +CDs
Freq 0and:
F.@ GHF.I 1#J
a. Ch spacing* 4E +#J
b. Transmitter out put power* 45@I dbm (changeable)
c. Power in put of ,'>* 5EF 2'C (5<F to 5?@ 2'C)
)ommunication $ang:
<@ K+ one to one.
Power $uppl! $2(5 ?4@*
a. ,n put 2oltage* @<6DE66 2&C I6DA6 #J
b. ,n put current* ADF &mp
c. "ut put 'C voltage* EFDA6 2'C
d. "ut put current* ?IDA6 &mp
T$ANSM*TT($
,n electronics and telecommunications a transmitter or radio transmitter is an
electronic device which, with the aid of an antenna, produces radio waves. The
transmitter itself generates a radio frequenc! alternating current, which is applied
to the antenna. %hen e-cited b! this alternating current, the antenna radiates radio
waves . The term is popularl! used more
speci8call! to refer to transmitting equipment used for broadcasting, as in radio
transmitter or television transmitter. This usage usuall! includes both the
transmitter proper as described above, and the antenna, and often the building it is
housed in.
$()(*+($
& radio receiver is an electronic circuit that receives its input from an antenna, uses
electronic 8lters to separate a wanted radio signal from all other signals picked up
b! this antenna, ampli8es it to a level suitable for further processing, and 8nall!
converts through demodulation and decoding the signal into a form usable for the
consumer, such as sound, pictures, digital data, measurement values, navigational
positions, etc.
,n consumer electronics, the terms radio and radio receiver are often used
speci8call! for receivers designed for the sound signals transmitted b! radio
broadcasting services.
ANT(NA
&n antenna (or aerial) is an electrical device which couples radio waves in free
space to an electrical current used b! a radio receiver or transmitter. ,n reception,
the antenna intercepts some of the power of an electromagnetic wave in order to
produce a tin! voltage that the radio receiver can amplif!. &lternativel!, a radio
transmitter will produce a large radio frequenc! current that ma! be applied to the
terminals of the same antenna in order to convert it into an electromagnetic wave
(radio wave) radiated into free space. &ntennas are thus essential to the operation
of all radio equipment, both transmitters and receivers. The! are used in s!stems
such as radio and television broadcasting, two5wa! radio, wireless 3&N, mobile
telephon!, radar, and satellite communications.
T!picall! an antenna consists of an arrangement of metallic conductors (or
LelementsL) with an electrical connection (often through a transmission line) to the
receiver or transmitter. & current forced through such a conductor b! a radio
transmitter will create an alternating magnetic 8eld according to &mpMre9s law. "r
the alternating magnetic 8eld due to a distant radio transmitter will induce a
voltage at the antenna terminals, according to =arada!9s law, which is connected to
the input of a receiver. ,n the so5called far 8eld, at a considerable distance awa!
from the antenna, the oscillating magnetic 8eld is coupled with a similarl!
oscillating electric 8eld: together these de8ne an electromagnetic wave which is
capable of propagating great distances.
Physical Transmission
Ph!sical transmission media use wire, cable, and other ph!sical materials to send
communications signals.
(-amples of ph!sical transmission media are
Twisted5pair cable
Coa-ial cable
=iber5optic cable
Fi'er-&%tic )ommunication
=iber5optic communication is a method of transmitting information from one
place to another b! sending pulses of light through an optical 8ber. The light forms
an electromagnetic carrier wave that is modulated to carr! information. =irst
developed in the 4N?6s, 8ber5optic communication s!stems have revolutionied the
telecommunications industr! and have pla!ed a ma7or role in the advent of the
,nformation &ge. Cecause of its advantages over electrical transmission, optical
8bers have largel! replaced copper wire communications in core networks in the
developed world.
The process of communicating using 8ber5optics involves the following basic
steps* Creating the optical signal involving the use of a transmitter, rela!ing the
signal along the 8ber, ensuring that the signal does not become too distorted or
weak, receiving the optical signal, and converting it into an electrical signal.
Synchronous digital hierarchy 1S!.2
$!nchronous digital hierarch! ($'#) are standardied multiple-ing protocols
that transfer multiple digital bit streams over optical 8ber using lasers or light5
emitting diodes (3('s). 3ower data rates can also be transferred via an electrical
interface. The method was developed to replace the Plesiochronous 'igital
#ierarch! (P'#) s!stem for transporting larger amounts of telephone calls and data
tra.c over the same 8ber without s!nchroniation problems.
Transmitter 'lock diagram Synchronous digital hierarchy 1S!.2
$eciever 'lock diagram Synchronous digital hierarchy 1S!.2
(-chang
e
$T+ 3ine
card
convert
"'= Cable
(-chang
e
$T+ 3ine
card
convert
"'= Cable
34 Tools and A%%aratus sed *n a Fi'er &%tic )ommunication:
"ptical Power +eter. (Prevail)
$ource +eter. (&cterna)
"ptical Tme 'omain 0efelecter. (&cterna)
2ariable &ttenuator. (&cterna)
"ptical =ibre =ussion $plicing +eter. (+icro Core)
Network Management System 1NMS2
& Network +anagement $!stem (N+$) is a combination of hardware and
software used to monitor and administer a network. ,ndividual network elements
(N(s) in a network are managed b! an element management s!stem.
=ollowing 3(')s in N+$ shows *
4. 1reen (Normal)
@. Oellow (%eak &larm)
<. $trong ($trong &larm)
E. 0ed (Critical Condition)
W(M (Wa*"&"n+', $i*ision m%&'i!&"-in+):
/n fiber8optic communications, .a*"&"n+',/$i*ision m%&'i!&"-in+ #W(M$ is a technology
which multiple:es a number of optical carrier signals onto a single optical fiber by using
different wavelengths #colors$ of laser light. This techni9ue enables bidirectional
communications over one strand of fiber, as well as multiplication of capacity.
The term wavelength-division multiplexing is commonly applied to an optical carrier #which is
typically described by its wavelength$, whereas fre9uency8division multiple:ing typically applies
to a radio carrier #which is more often described by fre9uency$. Since wavelength and frequency
are tied together through a simple directly inverse relationship, the two terms actually describe
the same concept.
-ense wavelength division multiple:ing, or -@-; for short, refers originally to optical signals
multiple:ed within the 122* nm band so as to leverage the capabilities #and cost$ of erbium
doped fiber amplifiers #(-=+s$, which are effective for wavelengths between appro:imately
1212>12!2 nm #C band$, or 12C*>1!1* nm #% band$. (-=+s were originally developed to
replace S4N(TES-3 optical8electrical8optical #4(4$ regenerators, which they have made
practically obsolete. (-=+s can amplify any optical signal in their operating range, regardless of
the modulated bit rate. /n terms of multi8wavelength signals, so long as the (-=+ has enough
pump energy available to it, it can amplify as many optical signals as can be multiple:ed into its
amplification band #though signal densities are limited by choice of modulation format$. (-=+s
therefore allow a single8channel optical link to be upgraded in bit rate by replacing only
e9uipment at the ends of the link, while retaining the e:isting (-=+ or series of (-=+s through
a long haul route. =urthermore, single8wavelength links using (-=+s can similarly be upgraded
to @-; links at reasonable cost. The (-=+s cost is thus leveraged across as many channels as
can be multiple:ed into the 122* nm band.
W(M SYSTEM
+ @-; system uses a multiple:er at the transmitter to &oin the signals together, and a
demultiple:er at the receiver to split them apart. @ith the right type of fiber it is possible to have
a device that does both simultaneously, and can function as an optical add8drop multiple:er. The
optical filtering devices used have traditionally been etalons, stable solid8state single8fre9uency.
@-; systems are popular with telecommunications companies because they allow them to
e:pand the capacity of the network without laying more fiber. 7y using @-; and optical
amplifiers, they can accommodate several generations of technology development in their optical
infrastructure without having to overhaul the backbone network. Capacity of a given link can be
e:panded by simply upgrading the multiple:ers and demultiple:ers at each end.
This is often done by using optical8to8electrical8to8optical #4E(E4$ translation at the very edge of
the transport network, thus permitting interoperation with e:isting e9uipment with optical
interfaces.;ost @-; systems operate on single8mode fiber optical cables, which have a core
diameter of Fm.
CW(M(Coars" .a*"&"n+', $i*ision m%&'i!&"-in+):
The term <coarse wavelength division multiple:ing< was fairly generic, and meant a number of
different things. /n general, these things shared the fact that the choice of channel spacings and
fre9uency stability was such that erbium doped fiber amplifiers #(-=+s$ could not be utilized.
Prior to the relatively recent /TA standardization of the term, one common meaning for coarse
@-; meant two #or possibly more$ signals multiple:ed onto a single fiber, where one signal
was in the 122* nm band, and the other in the 101* nm band.
/n 1**1 the /TA standardized a channel spacing grid for use with C@-; #/TA8T 6.!).1$,
using the wavelengths from 11C* nm through 1!1* nm with a channel spacing of 1* nm.
#6.!).1 was revised in 1**0 to shift the actual channel centers by 1, so that strictly speaking the
center wavelengths are 11C1 to 1!11 nm$. ;any C@-; wavelengths below 1)C* nm are
considered <unusable< on older 6.!21 specification fibers, due to the increased attenuation in the
11C*>1)C* nm bands. Newer fibers which conform to the 6.!21.C and 6.!21.- standards, such
as Corning S;=81.e and Samsung @idepass nearly eliminate the <water peak< attenuation peak
and allow for full operation of all 1. /TA C@-; channels in metropolitan networks. =or more
information on 6.!21.C and .- compliant fibers please see the links at the bottom of the article.
The (thernet %G8) 1* 6bitEs physical layer standard is an e:ample of a C@-; system in which
four wavelengths near 101* nm, each carrying a 0.112 gigabit8per8second #6bitEs$ data stream,
are used to carry 1* 6bitEs of aggregate data.
The main characteristic of the recent /TA C@-; standard is that the signals are not spaced
appropriately for amplification by (-=+s. This therefore limits the total C@-; optical span to
somewhere near !* km for a 1.2 6bitEs signal, which is suitable for use in metropolitan
applications. The rela:ed optical fre9uency stabilization re9uirements allow the associated costs
of C@-; to approach those of non8@-; optical components.
C@-; is also being used in cable television networks, where different wavelengths are used for
the downstream and upstream signals. /n these systems, the wavelengths used are often widely
separated, for e:ample the downstream signal might be at 101* nm while the upstream signal is
at 122* nm.
(W(M(("ns" .a*"&"n+', $i*ision m%&'i!&"-in+)
-ense wavelength division multiple:ing, or -@-; for short, refers originally to optical signals
multiple:ed within the 122* nm band so as to leverage the capabilities #and cost$ of erbium
doped fiber amplifiers #(-=+s$, which are effective for wavelengths between appro:imately
1212>12!2 nm #C band$, or 12C*>1!1* nm #% band$. (-=+s were originally developed to
replace S4N(TES-3 optical8electrical8optical #4(4$ regenerators, which they have made
practically obsolete. (-=+s can amplify any optical signal in their operating range, regardless of
the modulated bit rate. /n terms of multi8wavelength signals, so long as the (-=+ has enough
pump energy available to it, it can amplify as many optical signals as can be multiple:ed into its
amplification band #though signal densities are limited by choice of modulation format$. (-=+s
therefore allow a single8channel optical link to be upgraded in bit rate by replacing only
e9uipment at the ends of the link, while retaining the e:isting (-=+ or series of (-=+s through
a long haul route. =urthermore, single8wavelength links using (-=+s can similarly be upgraded
to @-; links at reasonable cost.
O!'i) BWS 0122A (W(M SYSTEM(HUAWEI)
The 4ptiG 7@S 1!**+ -@-; system is a one kind of large8capacity multi8service and multi8
reach transmission -@-; e9uipment. /t is mainly developed for the market of North +merica.
Compliant @ith standard T%1 command interfaces, it has N(7S8compliant hardware
architecture and is also compliant with the A% and the =CC. Thus it meets all of the re9uirements
of the North +merican market. The 4ptiG 7@S 1!**+ provides integrated solutions for long8
haul backbone transmission networks, metropolitan backbone networks, and metropolitan
aggregative networks. /t is compatible with the S4N(T products of 3uawei to provide overall
solutions. /t can also access standard8compliant services such as S4N(T, S-3, (thernet, and
S+Ns.
Pro$%3' #"a'%r"s:
Lar+" 3a!a3i' an$ mo$%&ar $"si+n :
The 4ptiG 7@S 1!**+ multiple:es up to 1!* wavelengths in a single fiber. The total
unidirectional transmission capacity can reach 1!**6bEs. (mploying the modular design, the
4ptiG 7@S 1!**+ can easily be upgraded from )**6 up to 1!**6. The modular design is
good for installment investment and construction in phases, and hence effectively reduces the
initial investment. (thernet, 1*6( %+N, +T;, (SC4N, =/C4N, =iber Channel and any services
at the rate ranging from 0);bitEs to 1.26bitEs. The 4ptiG 7@S 1!**+ supports service
convergence functions. /t can multiple: 4C). services into 4C11 wavelength, and multiple:
1E)E. 6( services into a 1 1.26E26E 1*6 bitEs. /n addition, it supports multi8channel S+N and
video service convergence to save wavelength resources.
OA(M (O!'i3a& A$$4(ro! M%&'i!&"-"r) :
4ptiG 7@S 1!**+ provides "4+-; based on @avelength 7locker Technology. /t supports
remote software configuration, 4ffers 1**H wavelength addEdrop and pass8through capability,
/n8service upgrade and e:pansion without interruption to other services, integrated optical
wavelength e9ualization capability. "4+-; enables customers to configure the service more
fle:ibly, facilitates operation, and tremendously improves e9uipment maintainability.
O!'iona& S%!"r*isor 3,ann"& :
Supervisory channel of the 7@S 1!**+ can be an 4ptical Supervisory Channel #4SC$ or an
(lectric Supervisory Channel #(SC$. 4SCE(SC and N; software allow remote system
operation and service provisioning from any node on the network. Choosing (SC could save
some optical supervisory channel units. /n this mode, the optical transponder unit #4TA$
multiple:es the supervisory information into the service channel for transmission. (SC mode can
reduce comple:ity and improve system power budget, it is a cost8effective and reliable solution.
U&'ra &on+/,a%& 'ransmission '"3,no&o+ :
The ultra long8haul transmission technology includes the A%3 and the %3P #long 3op$ that can
be applied to different networks. To enable ultra long8haul transmission, 3uawei developed a
world8leading Super@-; technology which uses the patented coding and modulation mode
to perform code conversion on the transponder boards and finally generates e:cellent return8
to8zero#"D$ code for optical signal transmission. The Super@-; technology not only
enhances 4SN" tolerance, but also reduces the inter8code interference and the impact of
nonlinear effect, and improves system &itter suppression and P;- tolerance. /t can fulfill a
2***km transmission for 1*6 services without regenerator by integrating with +=(C, "aman
and e9ualization technologies, so as to meet the A%3 transmission re9uirement more cost8
effectively.
Com!r","nsi*" moni'orin+ an$ !r"*"n'i*" .arnin+ :
The built8in optical spectrum analyzer #4S+$ unit can measure the optical power of each
wavelength, the central wavelength, and the 4SN" accurately. /t is able to conduct overall
testing and monitoring for the running status of each wavelength on the network. 4ptiG 7@S
1!**+ can realize overall monitoring of the network. /t is also able to locate network faults
effectively and gives an early warning in time so as to improve the maintenance 9uality.
$witching
(5changes:
& central s!stem of switches and other equipment that establishes
connections between individual telephones. &lso called switchboard.
T!pes "f (-changes*
4. 3ocal (-change
@. Tandem (-change
<. Transit (-change
E. Combined (-change
I. +ain 1ate %a! (-change
#!d
Tanda
m
Karachi
Tandam
(-chang
e
#!d
Transit
(-chang
e
1lobal
(-chang
eP
Qasim
&bad
3atif&ba
d
Cantonme
nt
(-change @
'%'+ '%'+
(-change 4
(lectrical
%ires
(lectrical
%ires
"ptical
=iber
4. 3ocal (-change*
3ocal (-change provide the telephone connections locall!. &ll the
users will be connected to an! of the local e-change. The local
e-change does not contain an! kind of big equipments. ,t onl!
contain a '3> mostl! called 0emote '3>. That '3> can also be
operated from the tandem e-change that)s wh! it is known as
0emote '3>.

'3>
$+3& and $+3' Cards =or
$ubscribers.
+'=
'%'+
@. Tandem (-change*
&ll the local e-change of di/erent areas connect through the
tandem e-change. "ne cit! must have at least one tandem
Primar!
Cable
Cabine
t
'P4
Jero +ain
#ole (<
=eet 'eep)
$econdar! Cable
+'=
#oriontal Tag Clocks
2ertical Tag
Clocks
e-change. Tandem e-change provides the interface between
upper levels to the local e-change. The billing, records, and other
important tasks are performed in tandem e-change. The tandem
e-change contains ver! e-pensive and crucial equipments.
0esponsible person on the tandem e-change is &'( (&ssistant
'ivision (ngineer).
<. Transit (-change*
The Transit (-change is used to connect the Tandem (-changes.
& division must have a transit e-change.
E. Combined (-change*
,f a Transit (-change also avails the customers and it also work
as Tandem (-change then that e-change is called Combined
(-change.
I. 1ate wa! (-change*
CP $N
3T1
'%'+
CCN
C
'3>
Transit or Tandem
(-change
The 1lobal e-changes are used to route the calls internationall!
and connect to the foreign countries.
$witching*
,n the 8eld of telecommunications, a tele%hone switch is a s!stem of
electronic components that connects telephone calls. & central o6ce is the
ph!sical building used to house inside plant equipment including telephone
switches, which make telephone calls LworkL in the sense of making
connections and rela!ing the speech information.
,n the middle @6th centur!, each subscriber telephone number
required an individual pair of wires from the switch to the subscriber9s phone.
& t!pical central o.ce ma! have tens5of5thousands of pairs of wires that
appear on terminal blocks called the main distribution frame or MDF. &
component of the +'= is protection* fuses or other devices that protect the
switch from lightning, shorts with electric power lines, or other foreign
voltages. ,n a t!pical telephone compan!, a large database tracks
information about each subscriber pair and the status of each 7umper. Cefore
computeriation of Cell $!stem records in the 4NF6s, this information was
handwritten in pencil in accounting ledger books.
& softswitch is a central device in a telecommunications
network which connects telephone calls from one phone line to another,
t!picall! via the internet, entirel! b! means of software running on a general5
purpose computer s!stem. +ost landline calls are routed b! purpose5built
hardware, formerl! using ph!sical switchboards, but softswitches are the
dominant @4st centur! trend.
&lthough the term softswitch technicall! refers to an! such device, it is
more conventionall! applied to a device that handles ,P5to5,P phone calls,
while the phrase Laccess serverL or Lmedia gatewa!L is used to refer to
devices that either originate or terminate traditional Lland lineL (hard wired)
phone calls. ,n practice, such devices can often do both. &s a practical
distinction, a $k!pe5to5$k!pe phone call is entirel! ,P (internet) based, and so
uses a softswitch somewhere in the middle connecting the calling part! with
the called part!. ,n contrast, access servers might take a mobile call or a call
originating from a traditional phone line, convert it to ,P tra.c, then send it
over the internet to another such device, which terminates the call b!
reversing the process and converting the ,P call back to ,$'N digital or
analogDP$TN format, and connecting it to a destination phone number.
P.&N(S 1,*N( AN! "*$(2
Section
Phone, is a telecommunications device that transmits and receives sound, most
commonl! the human voice. Telephones are a point5to5point communication s!stem
whose most basic function is to allow two people separated b! large distances to
talk to each other. ,t is one of the most common appliances in the developed world,
and has long been considered indispensable to businesses, households and
governments. The word LtelephoneL has been adapted to man! languages and is
widel! recognied around the world.
HOW USER GET A TONE :
This can be easil! understand b! following block diagram*
$witch 0oom +'= Cabinet 'P $ubscriber
Switch $oom
& room, often an entire ;oor, containing switching equipment, especiall!
for telephone lines .,n the 8eld of telecommunications, a telephone
e-change or telephone switch is a s!stem of electronic components that connects
telephone calls. & central o.ce is the ph!sical building used to house inside
plant equipment including telephone switches, which make telephone calls LworkL
in the sense of making connections and rela!ing the speech information.
Main Distribution ra!e (MD)
/n telephone, a main $is'ri5%'ion #ram" #M(F or main #ram"$ is a signal distribution
frame for connecting e9uipment #inside plant$ to cables and subscriber carrier e9uipment
#outside plant$. The ;-= is a termination point within the local telephone e:change where
e:change e9uipment and terminations of local loops are connected by &umper wires at the ;-=.
+ll cable copper pairs supplying services through user telephone lines are terminated at the ;-=
and distributed through the ;-= to e9uipment within the local e:change e.g. repeaters and
-S%+;. Cables to intermediate distribution frames terminate at the ;-=. Trunk cables may
terminate on the same ;-= or on a separate trunk main distribution frame #T;-=$.
Distribution Point
+ point at which supplies andEor ammunition, obtained from supporting supply points by a
division or other unit, is broken down for distribution to subordinate units. -istribution points
usually carry no stocksI items drawn are issued completely as soon as possible.
Subs"riber
,n a public switched telecommunications network, the ultimate user, i.e., customer,
of a communications service .$ubscribers include individuals, activities,
organiations, etc. $ubscribers are usuall! sub7ect to tari/. $ubscribers do not
include communications s!stems operating personnel e-cept for their personal
terminals.
T#$es o% Net&or'
Pri!ar# Net&or'
MDF Cabinet
The above block diagram show primar! network. This network is known as
primar! because in it we use ducted cable which is unarmed
Secondary Network
Cabinet 'P
The above block diagram show secondar! network. This network is known as
secondar! because in it we use buried cable and lite armed.
,ocal Area Network
$witch 0oom +'= Cabinet 'P $ubscriber
The above block diagram show local area network. ,t is a combination of secondar!
and primar! network.
!FA 1!irect feed access2
& network is set to be a '=& if +'= of one e-change is connected with the +'= of
other e-change without an! support of cabinet.
T*( Network
& network is set to be a T,( if two or more +'= is connected within the boundaries.
7unction Network
& network is set to be a T,( if two or more +'= is connected out of the boundaries.
New Tele%hone )onnection 1NT)2
Procedure of o%ening a new num'er
89 F&$M
1overnment Capacit!* The requirements for govt capacit! is
to submit form with departmental letter and the designation
name b! which number can be allotted.
Private Capacit!* The requirements for private capacit! is to
submit form with N,C cop!, undertaking form, o.ce card
cop! and the name of person b! whom number is allotted.
:9 Possi'ility $e%ort 1P$2
&fter the form submission account branch want possibilit!
report from the &.(, &.( ask from his line men is there is our
network and possible to give them number.
;9 !emand Note
&fter the possibilit! report account branch issue the demand
note which is depend on user if he or she want to submit
that challan or the! want to pa! it with the bill.
<9 Advisory Note
,t is the authorit! the account branch gives advisor! note to
consultant &.( for opening in the new number.
=9 7um%er Sli%
&fter receiving advisor! note from account branch the &.(
have to make 7umper slip which he will send to switching
dept. to start a new number.
Master $ecord
0ecord of ever! number can be maintain in master record . ,t is a
8le based record not a computer or software based record.
Master $ecord of Phone Set
PN) (=or New Connection)
PNN ($hifting under save custod! change of number, change of
name and designation etc.)
PNNN (=inall! closed)
(%$'
J The Digital Electronic Switching System ((%$') is a powerful and
versatile switching s!stem for public communication networks.
J The basic function of a switching s!stem is setting up a temporar!
connection between two subscribers, with one subscriber notif!ing the
switching s!stem of the subscriber with whom connection is requested.
&ll 'igital (-changes are based on $tore Program Control ($PC).
J (%$' hardware is divided into 8ve sub5s!stem for all t!pes of (%$'
e-changes.
("S! Parts:
J &ccess Part ('3>, 3T1 R CCNC)
J $witching Part ($N)
J Control Part (CP)
4. '3> ('igital 3ine >nit)
The 'igital 3ine >nit ('3>) combines number of &nalog and
'igital $ubscriber lines.
@. 3T1 (3ine Trunk 1roup)
The 3ine Trunk 1roup (3T1) not onl! terminate 'igital 3ine >nits
('3>) but it also linked to other (-changes, '$C $witch board and PCS
$!stem (P0,).
<. $N ($witching Network)
The $witching $!stem ($N) provides the interconnections
between two subscriber lines.
E. CCNC(Common Channel $ignaling Network
Control)
To provide the signaling s!stem No. ? (CC$?) capabilit!, the
(%$' switch requires a TCommon Channel $ignaling Network
Controller (CCNC).
I. CP(Co5ordination Processor)
$ince the processing workload is distributed over several
microprocessor with in the (%$' s!stem, a common processor for
coordination tasks is e-tremel! useful. These function are handled b!
the Coordination Processor (CP).
(ver! $ubs!stem is equipped with at least one +icroprocessor.
These microprocessor used to spread functions over the entire
switching center.
!,
Digital Line Unit Controller ('3>C) is a Controller of 'igital 3ine
>nit ('3>).
,T/
Grou !rocessor "G!# is a controller of 3ine Trunk 1roup (3T1).
SN
Switch Grou Control ($1C) is a controller of $witching Network
($N).
))N)
Common Channel Signaling $etwor% !rocessor "CC$!# is a
controller of Common Channel $ignaling Network Control (CCNC).
)P
System !anel Control ($OPC) and Message &u'er Control (+CC)
is a controller of Co5"rdination Processor (CP).
,nterfaces
J The interfaces of an (%$' switching s!stem can be divided into*5
J (-ternal ,nterfaces ('3> R 3T1)
J ,nternal ,nterfaces (CCNC, $N R CP)
(%$' (-changes
J +obile (-change
J 0uralDContainer (-changes
J 3ocal (-change
J Transit (-change
J Combined (-change
J ,1( 1atewa! (-change
J Tandem (-change
!igital Su'scri'er ,ine:
.*ST&$>

Implementation of Digital Subscriber Line technology originally was part of the Integrated
Services Digital Network ISDN! specification published in "#$% by the CCI&& and I&' as part
of (ecommendation I)"*+, later reused as ISDN Digital Subscriber Line IDSL!) -ngineers have
developed higher.speed DSL facilities such as /igh bit rate Digital Subscriber Line /DSL! and
Symmetric Digital Subscriber Line SDSL! to provision traditional Digital Signal " DS"! services
over standard copper pair facilities) Consumer.oriented 0symmetric Digital Subscriber Line
0DSL!, first tested at 1ellcore in "#$$, was designed to operate on e2isting lines already
conditioned for 1(I ISDN services, which itself is a switched digital service non.I3!, though
most incumbent local e2change carriers IL-Cs! provision (ate.0daptive Digital Subscriber Line
(0DSL! to work on virtually any available copper pair facility4whether conditioned for 1(I or
not)
&he development of DSL, like many other forms of communication, can be traced back to
Claude Shannon5s seminal "#%$ paper6 0 Mathematical &heory of Communication) -mployees
at 1ellcore now &elcordia &echnologies! developed 0DSL in "#$$ by placing wide.band digital
signals above the e2isting baseband analog voice signal carried between telephone company
telephone e2changes and customers on conventional twisted pair cabling facilities)7"8
0 DSL circuit provides digital service) &he underlyingtechnology of transport across DSL
facilities uses high.fre9uency sinusoidal carrier wave modulation, which is an analog signal
transmission) 0 DSL circuit terminates at each end in a modem which modulates patterns of bits
into certain high.fre9uency impulses for transmission to the opposing modem) Signals received
from the far.end modem are demodulated to yield a corresponding bit pattern that the modem
retransmits, in digital form, to its interfaced e9uipment, such as a computer, router, switch, etc)
'nlike traditional dial.up modems, which modulate bits into signals in the :++;:%++ /<
baseband voice service!, DSL modems modulate fre9uencies from %+++ /< to as high as %
M/<) &his fre9uency band separation enables DSL service and plain old telephone service
3=&S! to coe2ist on the same copper pair facility) >enerally, higher bit rate transmissions
re9uire a wider fre9uency band, though the ratio of bit rate to bandwidth are not linear due to
significant innovations in digital signal processing and digital modulation
Di(ital Subs"riber )ine:
Digital Subscriber Line DSL! is a family of technologies that provides digital data transmission
over the wires of a local telephone network) DSL originally stood for digital subscriber loop) In
telecommunications marketing, the term Digital Subscriber Line is widely understood to mean
0symmetric Digital Subscriber Line 0DSL!, the most commonly installed technical variety of
DSL) DSL service is delivered simultaneously with regular telephone on the same telephone
line)
&his is possible because DSL uses a higher fre9uency) &hese fre9uency bands are
subse9uently separated by filtering)
&he data throughput of consumer DSL services typically ranges from *?@ kbitAs to %+ MbitAs in
the direction to the customer downstream!, depending on DSL technology, line conditions, and
service.level implementation) In 0DSL, the data throughput in the upstream direction, i)e) in the
direction to the service provider! is lower, hence the designation of asymmetric service)
In the case of 0DSL, competition in Internet access caused subscription fees to drop
significantly over the years, thus making 0DSL more economical than dial up access) &elephone
companies were pressured into moving to 0DSL largely due to competition from cable
companies, which use D=CSIS cable modem technology to achieve similar speeds) Demand
for high bandwidth applications, such as video and file sharing, also contributed to populari<e
0DSL technology)
Most residential and small.office DSL implementations reserve low fre9uencies for 3=&S
service, so that with suitable filters andAor splitters! the e2isting voice service continues to
operate independent of the DSL service) &hus 3=&S.based communications, including fa2
machines and analog modems, can share the wires with DSL) =nly one DSL BmodemB can use
the subscriber line at a time) &he standard way to let multiple computers share a DSL
connection uses a router that establishes a connection between the DSL modem and a
local -thernet)
DI0>(0M
E*ui$!ent
&he customer end of the connection consists of a terminal adaptor or in layman5s terms
BDSL modemB) &his converts data between the digital signals used by computers and
the voltage signal of a suitable fre9uency range which is then applied to the phone line)