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00000CS307121902

Pages: 3

Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
Fifth semester B.Tech degree examinations (S) September 2020

Course Code: CS307
Course Name: DATA COMMUNICATION

PARTA
Answer all questions, each carries 3 marks.
Explain the three most significant transmission impairments.
Express the Time domain and frequency domain representations of a signal
with frequencies 0, 8 and 16Hz.
Transmission characteristics of Fibre Optic cable differs from Coaxial cable.
How?
For multicast communications which type of wireless transmission waves are
suitable? Justify your answer.
PART ப
Answer any two full questions, each carries 9 marks.
A telephone line is known to have a loss of 20dB. The input signal power is
measured as 0.5W, and the output noise level is measured as 4.5. W. Using this
information, calculate the output signal to noise ratio in dB.
Find the maximum distance between two antennas for LOS transmission if one
antenna is 100 m high and the other is at ground level.
Explain in detail transmission modes of Fibre optic cable?
How capacity of a system is determined in the presence of noise? We have a
channel with ೩ 1۸187 bandwidth. The SNR for this channel is 63. Then
calculate channel capacity.
How Nyquist theorem applied for a noiseless channel? We need to send 265
kbps over a noiseless channel with a bandwidth of 20 kHz. How many signal
levels do we need?

Briefly discuss Line of Sight propagation.

Duration: 3 Hours

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