SHREE RAMKRISHNA INSTITUTE OF SCIENCE & TECHNOLOGY

Dakshin Gobindapur, P.S. Sonarpur, Kolkata 700145,

(Approved by AICTE and affiliated to WBSCTE&VE&SD)

Department: ELECTRONICSAND TELECOMMUNICATION ENGINEERING

Lab manual for the course:

MOBILE COMMUNICATION

(Course code: ETCE/LMC/S5)

Prepared by SOUMEN MAITY in ETCE Department

ShreeRamkrishnaInstituteofScience&Technology,

DakshinGobindapur,Kolkata700145
VISION:
To ensure that the Diploma level Technical Education constantly matches the latest
requirements of technology and industry and includes the all-round personal
development of students including social concerns and to become globally competitive,
technology led organization.

MISSION:
To provide high quality technical and managerial manpower, information and consultancy
services to the industry and community to enable the industry and community to face the
changing technological and environmental challenges.

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

The Program Educational Objectives of the department of Electronics and Communication
Engineering (ETCE) of Shree Ramkrishna Institute of Science & Technology intend to
produce engineers who will be able to:

 ECPEO 1: Apply the fundamental concept of basic science along with the acquired
knowledge on the core subjects in Electronics and Communication Engineering and
pursue as an engineer and/or consultant and entrepreneur in their area of expertise.
 ECPEO 2: Apply their technical ideas in the development of interdisciplinary and
innovative systems considering the socio-economic conditions to execute the ideas
in a more realistic manner, and to emerge as a competent technologist, educator
and/or researcher.
 ECPEO 3: To work as a team with professional principles and high standard of ethics
and have a successful career in industries or R & D organizations.

PROGRAMME SPECIFIC OBJECTIVES (PSOs):

Followingprogrammeoutcomesareexpectedtobeachievedthroughthepracticalofthe
course

PO1. Basic knowledge:Maintain various types of Electronicsand

Telecommunication systems.Investigate specific theoretical and experimental
problems in relevance with basic engineering to solve the broad-based
Electronics and Telecommunication engineering problems.

P02. Disciplineknowledge:Design Electronicsand Telecommunication engineering

knowledge to solve broad-based Electronics and Telecommunications engineering
related problems.
 P03. Experiments and practice: Experiments and practice: Plan to perform
experiments and practices to use the results to solve broad-basedElectronics and
Telecommunicationengineering problems.

Course/Subject: MOBILE COMMUNICATION

(Course code: ETCE/LMC/S5)

Course Outcomes (COs):

a. Troubleshoot mobile handsets.

b. Assess cellular systems capacity.
c. Assess performance of standards of different cellular mobile systems.
d. Select relevant wireless technology suitable for various applications.
e. Test the performance of various wireless protocols.
EXPERIMENT :
Identify different sections and components of mobile Phone.
OBJECTIVE:
We can connect to the network from anywhere, with anybody, at anytime. Mobile phones
play a very important role in making this connectivity possible. A knowledge of the various
components of the mobile handset helps in troubleshooting and maintenance of the
handsets. This practical will help the student identify different sections of the mobile phone
unit.

THEORY:A mobile phone (also known as a cellular phone, cell phone, hand phone, or
simply a (phone) is a phone that can make and receive telephone calls over a radio link
while moving around a wide geographic area. It does so by connecting to a cellular network
provided by a mobile phone operator, allowing access to the public telephone network.

Apparatus Required:

Sr. Instrument
Specification Quantity
No. /Components
1. GSMTrainerKit 2G/3G/4GGSMtrainerkit 1No.
2. SIMcard Anytypemicro,NanoorStandardSIM 1No.

Procedure:
1.Observe the block diagram of the mobile handset available in the laboratory
2.Observe various sections on the trainer kit and list its specifications
3.Insert the SIM card in the slot provided in the trainer kit and select the operator
manually.
 Sl no Components Specification Quality

Result:
The function of transmitter and receiver is ________________
The various blocks in a mobile phone unit are_____________________
The different types of SIM are

Precautionstobe Followed:
 ReadtheinstructionmanualoftheGSMtrainerkitbeforeapplyingpower.
 Try to identify the SIM slot and the type of SIM to be inserted before purchase of
SIM since there are 3 types of SIM in different sizes.

EXPERIMENT :
Test the supply of the transmitter /receiver section of mobile phone unit.
OBJECTIVE:A mobile phone consists of various sections that include transmitter/ receiver
section, buzzer and vibrator section, power supply section, display section, SIM card section.
To troubleshoot a mobile handset, it is necessary to understand the type of waveforms and
the voltages and currents at the output of these sections.
THEORY:
Transmitter and Receiver section: Signal to the transmitter is the audio signal from the
microphone of the mobile handset. This analog / audio signal is converted intodigital signal
by the ADC. It is further modulated by the GMSK scheme and the modulated signal is
transmitted through a transmitting antenna.
The signal to the receiver is the modulated signal which is demodulated into digital signal.
This digital signal is converted into analog form with the help of DAC. The analog signal is
then given to the speaker.
 Fig: Receiver and Transmitter sections

Sr.
Instrument/Components Specification Quantity
No.
1. GSMTrainerKit 2G/3G/4GGSMtrainerkit 1No.
2. CRO/DSO 20MHz,dualtrace,dualbeam, 1No.
3. Spectrumanalyser 1 GHz 1No.
4. DMM 3½Digit 1No.
5. Connectingwires Bananaplugs 4No.

CircuitDiagram:
BlockschematicofTransmitter

10.7o:r4SSkHz

rn
DNODUI.ATO

'!)Ampli!lclt

WQAmplifier

Serial digitalila13J_,BP!:
olegicunit

BlockschematicofReceiver

APPARATUS REQUIRED:
Sl.
Instrument/Components Specification Quantity
No.
1. GSMTrainerKit 2G/3G/4GGSMtrainerkit 1No.
2. CRO/DSO 20MHz,dualtrace,dualbeam, 1No.
3. Spectrumanalyser 1 GHz 1No.
4. DMM 3½Digit 1No.
5. Connectingwires Bananaplugs 4No.

Procedure:

1. Connect the power cord to the trainer kit. Insert the SIM card in the position
provided and tum on the power supply

2. Make a call to the mobile trainer kit from any other mobile or landline number.

3. While the call is ON, observe the signal on the CRO/Spectrum analyzer and
record the same.

4. Make a call from the mobile trainer kit to some mobile or land line.

5. While the call is ON, observe the signal on the CRO/Spectrum analyzer and
record the same.
Observations:

Transmitter Section

Audio
Input

Antenna
Signal

Receiver Section:

AudioInput

Demodulated Output
 Speaker
output

Result:

Thevoltageofthetransmittingantennais-----------------------------------------------------
Thevoltageofthereceivingantenna---------------------------------------------------------
Theoutputofthespeakeris

Precautions:

1. Read the instruction manual of the GSM trainer kit before applying power.

2. Install the SIM with care.

PracticalRelatedQuestions:

1.Statethetypeofantennausedina givenmobilephone.
2.GMSKmodulationtechniqueisusedinGSMmobile.Givereason
3.StatetheuseofHagarICusedinmobile.
4.Frommobilesettings,determinetheoperatingsystemused.

EXPERIMENT :
Perform the process of call connection and call release of cellular Mobile System
Objective:The command set consists of a series of short text strings which can be combined
to produce commands for operations such as dialing, managing SMS functions and changing
the parameters of the connection
THEORY:
Mobile call origination in GSM:
1. The MS sends the dialed number indicating service requested to the MSC(via BSS)
2. The MSC checks from the VLR if the MS is allowed the requested service.If so, MSC asks
BSS to allocate necessary resources for the call.
3. If the call is allowed,the MSC routes the call to GMSC.
4. The GMSC routes the call to the local exchange of called user.
5. The LE alerts (applies ringing) the called terminal.
6. Answer back (ring back tone) from the called terminal to LE.
7. Answer back signal is routed back to the MS through the serving MSC which also
completes the speech path to the MS.

Mobile call termination:

1. The PSTN user dials the MSISDN of the called user in GSM.
2. The LE routes the call to the GMSC of the called GSM user.
3. The GMSC uses the dialed MSISDN to determine the serving HLR for the GSM user and
interrogates it to obtain the required routing number.
4. The HLR requests the current serving VLR for the called MS for a MSRN (MS roaming
number) so that the call can be routed to the correct MSC.
5. The VLR passes the MSRN to the HLR.
6. The HLR passes the MSRN to the GMSC.
7. Using the MSRN, the GMSC routes the call to the serving MSC.
8. The MSC interrogates the VLR for the current location area identity (LAI) for the MS.
9. The VLR provides the current location for the MS.
10. The MSC pages MS via the appropriate BSS. The MS responds to the page and sets up
the necessary signaling links.
11. When the BSS has established the necessary radio links. the MSC is informed and the
call is delivered to the MS.
12. When the MS answers the call, the connection is completed to the calling PSTN user.
Precautions to be followed :
1. Insert SIM Card Properly.
2. Make sure the SIM is having network coverage.
:3. Type the AT Commands after reading their use, as it might reset/Format the SIM Data.

Procedure Steps for connecting GSM Modem with Hyper terminal software:
1. Connect the setup as shown in the block diagram given below.
2. 2. Start the PC and load the required software for GSM modem/Trainer.
3. 3. Start the Hyper terminal software.
4. 4. Open File->New Connection.
5. Set the COM1 properties with default values as: Speed/Baud rate:9600 Data Bits:8 Parity:
None Stop Bit:1 Flow Control: None
6. Type “AT” on the screen (command line) and detect connection by receiving response
“OK”
7. Type the various commands and check their responses.
8. Record the responses of given various commands in the observation table.
Observations:
(Use blank sheet provided if space not sufficient) Observe Command response and write
their Responses.

SlNo. Command Response

Practical related Questions Note:

1. What do you mean by PSTN?
2. What is the effect of field strength on call connection?
3. List Network Service types.
4. State the websites providing free SMS service.
5. What is the additional band proposed for 4G mobile system? How a user is alerted for the
incoming call using paging mechanism of mobile network.

EXPERIMENT :
Determine the coverage area of a split cell which has radius half the radius
of original cell.
OBJECTIVE:A cell is the geographical area covered by a cellular telephone transmitter.
Cell splitting increases the capacity of the cellular system since it increases the number of
times the channels are reused. In this practical the student will be able to study the effect of
changing the radius of the cell.
THEORY:A cell is a geographical area covered by a cellular telephone transmitter. The
radius of a cell varies from a few kilometers to several kilometers, depending on the terrain
and the transmission power. As the demand for wireless service increases ,the number of
channels assigned to a cell eventually becomes insufficient to support required number of
users. Cellular design techniques are required to provide more channels per unit coverage
area. Techniques such as cell splitting, Cell sectoring and coverage zone approaches are used
in the practice to expand the capacity of cellular systems. Cell splitting allows an orderly
growth of cellular system. Cell sectoring uses directional antenna to further control the
interference and frequency reuse of channels. The zone microcell concept distributes the
coverage of the cell and extends the cell boundary to hard-to- reach places.
Cell splitting is the process of subdividing a congested cell into smaller cells, each with its
own base station and a corresponding reduction in antenna height and transmitter power.
Cell splitting improves the capacity of the cellular system since it increases the number of
times the same frequency channels are reused. By defining new cells between the existing
cells, capacity increases due to additional number of channels per unit area.

Cellsplitting
Procedure:
1.Drawa 7cellclusterina graphpaperwitheachsegmentofthehexagontobe1 cm.
2.MarkthemasA,B,C,D,E,FandG
3.Markthecentrepointofeachsideofeachhexagon
4.Draw all the possiblesmallerhexagonswith halfthe lengthof the side withinthe cluster.
5.Count the number of suchsmallhexagonsformed
6.Comparethenumberwiththetheoreticalvalueusingtheformula.

hexagonside=1cmhexagonside=1/2cm
Number of
cells in the
cluster N=7
Practical(from Practical
Theoretical Theoretical
Areaofthe graph) (fromgraph)
hexagon

Calculation:
Consider area covered by hexagon is equal to the area of a circle. The area of circle with
radius R is n R2
If the radius id halved then the area covered will be n(R/2)2 The area covered by the circle
with half the radius is n R2/4.
Result:
Comment on the height of antenna and the power transmitted by large cell and small cell.

Practical Related Questions:

1.State the effect of cell splitting on signal to inference ratio.
2.State the number of smaller cells of half the length of side in a cluster with size 12.
3. State the relationship between the transmit powers of large cell and small cell base
stations.

Precautions :

1.Read the instruction manual of the GSM trainer kit before applying power.
2.Install the SIM with care.