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T.Y. Diploma : Sem. VI [EJ/ET/EX/EN/ED/EI] Mobile Communication

Time : 3 Hrs.] MSBTE Specimen Question Paper Solution [Marks : 100

Q.1(a) Attempt any THREE of the following : [12]Q.1(a) (i) Define the term Handoff? State the different strategies of

Hand-off and name the Hand-off used in IS-95 system. [4]

(A)

Q.1(a) (ii) List the following specification of EDGE2.5 G standards. 1) Data rate 2) Modulation technique3) Channel Bandwidth 4) Duplexing technique

[4]

(A) 1) Data rate

2)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Q.1(a) (iii) Which system is best from GSM, IS 136 and IS 95? Justify

your answer with any 4 points. [4]

(A)

Gaussian minimum shift keying Differential quadrature phase shift keying Offset QPSK A “chip” is used to demote a spread symbol in DS-CDMA systems Regular pulse excited long term prediction Vector sum excited linear predictive Algebraic code excited linear predictive

3)

4) Vidy

alank

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MSBTE Specimen Question Paper Solution

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Q.1(a) (iv) Illustrate the general operation of cordless telephone system with block diagram.

[4]

(A)

Q.1(b) Attempt any ONE of the following : [6]Q.1(b) (i) Draw the GSM architecture and write function of each block. [6](A)

Mobile Station

Base Station Subsystem Network Subsystem

SIM Subscriber Identity Module BSC Base Station Controller MSC Mobile Services Switching Center ME Mobile Equipment HLR Home Location Register EIR Equipment Identity Register BTS Base Transceiver Station VLR Visitor Location Register AuC Authentication Center Vidy

alank

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Vidyalankar : T.Y. Diploma MC

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Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Q.1(b) (ii) Illustrate the process of call initiation from landline telephone to cellular phone with timing diagram.

[6]

(A)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Outgoing Call Setup Procedure : To make a call to the target user the steps are as follows : i) The source user dials the MSISDN number of the target and press dial button. ii) The source MS sends the call request to serving BTS by using uplink signaling

channel. iii) If the network can process the call, then network setup the connection with the

target MS. iv) MSC determines the current location of target mobile by using information

stored in HLR, VLR or by communicating with other MSCs. v) Source MSC initiates a call setup message to MSC covering target area in which

the target mobile is present.

Q.2 Attempt any FOUR of the following : [16]Q.2(a) Illustrate concept of cell sectoring with diagram. [4](A)

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Q.2(b) State any four specification of CDMA-2000. [4](A)

Q.2(c) Name the system A and B which supports following features. [4]

Parameter A Parameter B Frequency Band 2400-2483.5

MHz Packet Data Rate 384 kbps

Duplexing Method with Frequency Hopping

TDD Duplexing Method TDD

Channel Bandwidth 1 MHz Channel Bandwidth 1.6 MHz Modulation Technique GFSK Antenna Used Smart

Antenna

(A) System A = Mobile Satellite Communication System B = GPRS Q.2(d) Distinguish between GPRS standards with IS-95B w.r.t

i) Backward compatibility ii) Channel bandwidth iii) Data rate iv) Number of voice channels

[4]

(A) Parameter GPRS IS-95B

Backward compatibility No Yes Channel bandwidth 200KHz 1.25MHz

Data rate 9.6kbps 115kbps Number of voice channels No 53

Q.2(e) Give any four applications of MANET. [4](A)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Q.2(f) Calculate the capacity for cluster size of 7 in cellular system whichhas 504 radio channels available for handling traffic. Calculate number of channels per cell. If number of cluster available incellular system are 7 then calculate capacity of system.

[4]

(A)

Q.3 Attempt any FOUR of the following : [16]Q.3(a) Draw block diagram of cellular transmitter and write the function of

each block. [4]

(A)

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Q.3(b) Illustrate signal flow sequence for call in GSM. [4](A)

Q.3(c) Draw micro-cell zone concept and write how it can be used to

minimize number of handoff. [4]

(A)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

10

Q.3(d) State any four specifications of UMTS. [4](A)

Q.3(e) State the services of SS7 in detail. [4](A)

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Q.4(a) Attempt any THREE of the following : [12]Q.4(a) (i) State any four specifications of IMT 2000. [4](A)

Q.4(a) (ii) Give classification of GSM logical channels. [4](A)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Q.4(a) (iii) List down the features of HSCSD 2.5G w.r.t

1) Channel bandwidth 2) Duplexing method 3) Data rate 4) Backward compatibility

[4]

(A)

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Q.4(a) (iv) What is cell splitting? State its types. [4](A)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

14

Q.4(b) Attempt any ONE of the following : [6]Q.4(b) (i) Draw system architecture of cellular system and write its

operation. [6]

(A)

Q.4(b) (ii) Illustrate SS7 protocol architecture with labeled diagram andwrite the function of each layer.

[6]

(A)

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Q.5 Attempt any FOUR of the following : [16]Q.5(a) Draw block diagram of Logic unit and write the function of each

block. [4]

(A)

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Q.5(b) Compare AMPS, IS-95, GSM and NAMPS w.r.t. Frequency bandand Channel bandwidth.

[4]

(A)

Q.5(c) Draw forward channel structure of IS-95 and write function of each channel in it.

[4]

(A)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Q.5(d) Draw Wireless Local Loop and write any four benefits of wirelesslocal loop.

[4]

(A)

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Q.5(e) Give importance of blockage, voice channel blockage, word error rate and call drop in cellular communication system.

[4]

(A)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Q.5(f) Define mobile base station, mobile control station, co-channel

interference and system capacity. [4]

(A)

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Q.6 Attempt any FOUR of the following : [16]Q.6(a) Identify and complete given block diagram. Also write frequency

ranges at the output of IF amplifier. [4]

(A)

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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Q.6(b) Differentiate GSM and IS-95 w.r.t. (i) Frequency range (ii) Channel bandwidth (iii) Radio interface (iv) Hand off

[4]

(A)

Q.6(c) Illustrate operation of wireless LAN in Ad-hoc mode with neat and

labeled diagram. [4]

(A)

(i)

(ii)

(iii)

(iv)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Q.6(d) Identify the given block diagram. State the effect of change in

divide by number obtains from logic unit to frequency divider blockon transmitter and receiver channel frequency.

[4]

Vidyala

nkar

MSBTE Specimen Question Paper Solution

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(A)

Q.6(e) Draw network reference model of IS 95 and explain it. [4](A)

Vidyala

nkar

Vidyalankar : T.Y. Diploma MC

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Vidyala

nkar