Tuesday, March 19, 2013

Optical Communication Networks Question Paper May/June Model 2013 Anna university chennai

M.E. – Communication Systems
First Semester
(Regulation 2010)
Time : Three hours Maximum : 100 marks
Answer ALL questions.
PART A — (10 ´ 2 = 20 marks)

1. List the main loss mechanisms in optical fibres.
2. What are solitons? What is their advantage?
3. Mention advantages of WDM.
4. List the different topologies used in optical networks.
5. What is a optical add/drop multiplexer?
6. What are the services provided by the optical layer?
7. What are the functions of a routing node?
8. What is an interleaved optical multiplexer?
9. Define extinction ratio.
10. What are the goals of performance and fault management?

PART B — (5 ´ 16 = 80 marks)
11. (a) Discuss in detail, the main categories of nonlinear effects that occur in
optical communication systems. (16)
(b) (i) Explain the advantages of optical amplifier over regenerators. (6)
(ii) Describe in detail, the principle of operation of an Erbium doped
fibre amplifier. (10)
12. (a) (i) Explain the advantages of SONET and SDH standards used in
optical networks. (4)
(ii) Describe the frame structure and network configurations defined
for SONET and SDH. (12)
(b) (i) Discuss the main features and mode of operation of broadcast and
select networks. (10)
(ii) Explain briefly the test beds for Broadcast and select WDM
networks. (6)
13. (a) Discuss how by providing networking functions within the optical layer,
significant cost saving is achieved. (16)
(b) (i) What problems are encountered in routing and wavelength
assignment? (8)
(ii) Explain how wavelength conversion can be used in fibre networks.
14. (a) (i) Explain synchronization in photonic packet switching network. (4)
(ii) Describe how synchronization is achieved using tunable delays and
optical phase lock loop. (12)
(b) Describe in detail, the architecture and classification of different types of
fibre access networks. (16)
15. (a) (i) Describe the two forms of crosstalk that arise in WDM systems. (8)
(ii) Explain the approach used for crosstalk reduction. (8)
(b) Discuss in detail equipment, connection and adaptation management
functions of configuration management. (16)