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

M.E./M.Tech. DEGREE EXAMINATION, JUNE 2011. M.E. – Communication Systems First Semester 251102 — OPTICAL COMMUNICATION NETWORKS (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) Or (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) Or (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) Or (b) (i) What problems are encountered in routing and wavelength assignment? (8) (ii) Explain how wavelength conversion can be used in fibre networks. (8) 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) Or (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) Or (b) Discuss in detail equipment, connection and adaptation management functions of configuration management. (16)