64241-mt----optical Fiber Communication

NR

Code No: 64241/MT

M.Tech. – II Semester Regular Examinations, September, 2008 OPTICAL FIBER COMMUNICATION (Communication Systems) Time: 3hours

1.a) b)

Max. Marks:60

Answer any FIVE questions All questions carry equal marks --What type of losses are there in optical fiber and explain how these are effect on bandwidth? What are the general requirements for a source in optical fiber communications? Explain whether the injection LASER fulfils these requirements.

2.a) b)

What is grating? Explain the principle of operation of it. Derive the power transfer function of the Fabery – Perot filter.

3.a) b)

What is quantum limit? Derive its expression. Explain the effect of thermal noise on the performance of simple direct detection receiver.

4.a) b)

Derive the expression for power penalty of receiver. Draw the simple coherent receiver and calculate the BER for it.

5.a) b)

Explain the process of multiplexing in SONET. Define the following: (i) ESCON (II) HIPPI

6.a)

Draw the block diagram of an optical line terminal and explain the function of each block. What type of functions are provided by OXC in a large network?

b) 7.a)

What are the differents functions of network management? Explain them. b) What type of indicator signals are used in network and what type of faults they indicate?

8.

Write a short notes on the following: (a) Adaption layers (b) BER measurement. &_&_&_&