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Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
FIFTH SEMESTER B.TECH DEGREE EXAMINATION, DECEMBER 2017

Course Code: CS307
Course Name: DATA COMMUNICATION (CS)

PART A
Answer all questions, each carries 3 marks.

Define simplex, half duplex and full duplex transmission mode. Give one
example for each.
List and explain different factors which determine the performance of
communication in a network?
Write physical and transmission characteristics of Optical Fibre Cable guided
transmission media.
What are the advantages of microwave transmission over radio wave
transmission?
For a parabolic reflective antenna with a diameter of 2m, operating at 12 GHz.
Calculate the antenna gain? Given effective area= 56%.

PART B

Answer any two full questions, each carries 9 marks.

(a) Explain time domain and frequency domain concept of a signal in a
communication system.

List various impairments and explain how they affect information carrying
capacity of a communication link?

How does cross talk occurs in twisted pair cables? Give the purpose of
CATSe,CAT6,CAT7 twisted pair cables.

Show that doubling the distance between transmission antenna and receiving
antenna attenuates the power received by 6dB.

Define Channel Capacity. What key factors affect highest data rate for noiseless
channel and noisy channel?

Signal to Noise Ratio is often given in decibels. Assume SNRq=36 and the
channel bandwidth is 2Mhz. Calculate theoretical channel capacity?

Explain following wireless propagation modes

(i) Ground wave propagation(ii) Sky wave propagation

PART C

Answer all questions, each carries 3 marks.
Give the significance of delta modulation over pulse code modulation during the
process of transforming analog data in to digital signal.
Show the equivalent analog sine-wave pattern of the bit string 00110101 using
amplitude shift keying, frequency shift keying andphase shift keying
What are the advantages of using multiplexing in data communication?How does
a synchronised time division multiplexer stay synchronized with de-multiplexer
on receiving end ?
What type of multiplexing is preferred in optical fibre communication? Justify
your answer

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Duration: 3 Hours

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