8th Semeste Electronics and Communication Engineering (June-2016) Question Papers

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Time: 3 hrs.
Note: Answer FIVE full questions, selecting
at least TWO questions from each purt.
PART _ A
a. Explain the various steps in AMPS mobile terminated call.
b. Explain the characteristics of 2G and 3G cellular systems.
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Eighth Semester B.E. Degree Examination, June/July 2016
Wireless Gommunication
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2 a. Explain the generation of MSISDN, IMSI and IMEI. (06 Marks)
b. Explain the function of HLR and ILR. (06 Marks)
c. Explain a mobile originated call in a cellular network with a neat flow diagram. (08 Marks)
3 a. A service provider is given license for total bandwidth of 5 MHz and each system subscriber
requires 10 kHz bandwidth. Determine the systern capacity if the service provider
implements a cellular system with 35 transmitter sites and cluster size of 7. (06 Marks)
b. Determine frequency reuse distance for a cluster size of 7 and a cell radius of 6 km.
(04 Marks)
c. Explain mobility rnanagement concept. Explain the functions of location management with a
figure. (10 Marks)
4 a. Explain the GSM signaling model. (10 Marks)
b. Explain the steps in call setup in GSM using mobile station roaming number. (10 Marks)
PART _ B
5 a. List out the ten operations in call setup in GSM system.
setting and IMEI ctreck.
Explain in detail ciphering mode
Explain GSIvI intia BSC handover operation with a figure.
Explain the functions of three layers in a network management system.
Exptraiq the generation of CDMA paging channel.
Explain the path loss model for free space propagation.
What is the received power in dBm for a signal in free space with a transmitting power of
1 kW, frequency of 1800 MHz and distance from the receiver of 2000 meters if the
transmitting antenna and receiving antennas have a gain of 1.6? What is the path loss in dB?
(05 Marks)
Explain frequency hopping and direct sequence spread spectrum techniques. (10 Marks)
Discuss the design issues of IEEE802.11 and explain the working of BSS, DS and ESS
network. (10 Marks)
Explain the'details of Bluetooth protocol stack with a figure. (10 Marks)
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Max. Marks:100
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Eighth Semester B.E. Degree Examination, uly 2016
Digital Switching Systems
Note: Answer FIVE fall questions, sele,cting
at lesst TWO questions from each part
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PART _ A
Draw a neat diagram of four-wire circuit and explain its working.
A four wire circuit has an overall loss (two-wire to two-wire) of 1
loss at each end is 6 dB. Find: i) The singing point;
iii) The attenuation of talker and listener echo.
Write a short note on European pleisockonous digital hierarchy.
Differentiate between message switching and circuit switching.
3 a. Derive the expression for second Erlang's distribution starting from basic principles.
(10 Marks)
b. Define the following terms:
, tsusy hour
iii) Pure chance traffic
c. On an average, one call arrives every 5 seconds. During a period of 10 seconds, what is the
probability that:
0 No call arrives?
iii) Two calls arrive?
Explain the functions of electronic switching.
With the hetrp of neat diagram, explain the basic types of calls that are
through a DSS.
ii) Grade of service
iv) Statistical equiiibrium
ii) One call arrives?
iv) More than two calls an'ive?
What is grading? Explain different types of grading. (06 Marks)
Derive the expression for grade of service of three stage netwnrk. (08 Marks)
Design a three stage network for 100 incoming trunks and 400 outgoing trunks. (06 Marks)
PART _ B
Explain S-T-S switching network with neat diagram. (06 Marks)
A'T-S-T network has 20 incoming and 20 outgoing FCM highway, each conveys 30
channels. The required GOS is 0.01, 0.02, 0.001, 0.005. Find the traffic capacity of network
a. Explain in brief basic software architecture of a typical DSS with neat diagram. (10 Marks)
b. With a neat diagram, expTain digital switching system software classification. (10 Marks)
in mode 1 and mode 2.
c. Explain the need for frame alignrnent in time division switching network.
a. Explain the organizational interfaces of typical DSS eentral office.
b. Explain with a neat diagram, a strategy for improving software quality.
Write short notes on:
a. Generic switch software architecture
c. Common characteristics ot'DSS
b. Recovery strategy
d. ,A.nalysis report for DSS (20 Marks)

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Examination, Jurie/July 2015
Security
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Mar. Marks:100
Eighth Sernester B.E. Degree
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st leasl TWU questions froxn each part.
PART - A
I a. With a neat diagram, explain network access security model with gate keeper function.
classify and expiain different type of attacks.
(05 Marks)
(08 Marks)
Using the keyword "ENCRYPT" create playfair matrix and obtain ciphertext for ttre
rnessage "MATCI{FIXED". Also write the rules used. (07 Marks}
2 a. Explain single round of DES along with the key generation.
b. Explain the working of counter mode of block cipher operation.
c. Discuss the final evaluation criteria of AES.
(1S Marks)
(04 Marks)
(06 Marks)
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(S6 Marks)
(04 Marks)
3 a. Justiff how both confidentiality and authentication are obtained in publickey cryprosystenas.
(S5 Marks)
b. Write RSA algorithm. (04 Marks)
c. In Diffie Hellman key exchange q:71, its primitive root cx,:7 A's private key is 5 B's
private key is 12. Find: i) A's public key; ii) B's pubiic key, iii) Shared secret key.
(05 Marks)
d" Expiain the distribution of secret key using the public key cryprography r,vith confidentialify
and authentication. (s5 Marks)
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List out the requirements and explain the arbitrated digital signature technique. (10 Marks)
b. Compare RSA and DSS approach. (06 Marks)
c. Illustrate replay attack with exarnples. (&4 Marks)
5a.
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6a.
b.
c.
7a"
b.
c.
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Explain the key requirennents and features of SET.
Discuss SSL record in terms of fragment compression and encryption.
Explain password selection strategies.
Describe statistical anomaly detection.
Discuss the different categories of intmders.
Describe digital immune system with diagram.
Brief on four generations of Antivirus software.
Give the taxonomy of malicious programs. Briefly explain all the software threats. (10 Marks)
a. What is firewall? Fxplain the various firewall configurations with relevant diagrarn"
(10 Marks)
b. Write short notes on:
i) Data Access Control
ii) Concept of Trusted system (X0 Marks)
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(04 Marks)
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Eighth Semester B.E. Degnee Examination, June/July 2015
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Note: Answev FIVE fwll questions, selecting
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rAB}"-A
Explain the otrjectives of GSh4 PI-MN.
With neat diagrarn, explain GSM Reference modei.
Explain Radio interf,ace (MS to tsTS) ier GSM interfaces.
Explain Smart Antenna and give their advantages.
Discuss about single level and quality level in GSM.
With neat diagram, exptrain base band frequency hopptr1g in GSM.
Explain the mobile identit'ication process with flow diagram.
Explain GSM Location area and cell area identification prclcess
management.
Wriie a note on synchronization Burst.
Explain GSM PLMN Bearer services and Teleservices in detail"
Explain time domain waveflorm coding with help of A - Law and pr -- Law.
PART _ B
5 a. What is hand over? Explain inter MSC hand over. (0E Marks)
b. Explain raobile teiephone Architecture for data interwcirking with neat block diagram.
(Sd h{arks)
(&6 tuIarks)
(tr0 Marks)
{1S Marks}
V a. Derive an expression for spectral efficiency in terms of voice and non voice transmission.
(10 Marks)
b. Derive an expression for Received signal strength of a base station Receiver. (10 Marks)
c. Explain pure ALOHA scherne with their throughput.
6 a. Explain various security algorithms for GSM in detail.
b. Explain the privacy Requirements in GSII{ security.
8 a. Explain the various TMN Layers in detail.
b. Explain the manager and agent roles in OSI systern managernent.
c. Write short note on SNMF"
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