SRM University 2007 B.Tech Electronics and Communications Engineering Bank : Wireless Communication - Question Paper

29. Define Erlang.

PART – B

1. With neat diagram discuss frequency reuse concept. Justify system capacity increases by frequency reuse with necessary mathematical equations.
2. What is Handoff? discuss handoff scenario with neat diagram.
3. Discuss elaborate the issues encountered in implementing handoff strategy and how they are resolved?
4. What is interference? discuss kinds of interference in detail.
5. Explain with diagram the dependence ranging from cell cluster size and interference.
6. Explain the various kinds of trunked systems used in cellular systems/
7. Write short note on (i) Multiple Access (ii) Channel Assignment
8. For a N=7 system with a probability of blocking =1% and avg. call length of 2 minutes, obtain the traffic capacity loss due to trunking for 57 channels when going from omni directional antennas to 60 degree sectored antenna. (Assume that BCC and ?=1/hour)
9. Assume every user of single base station mobile radio system averages 3 calls per hour, every call lasting an avg. of 5 minutes. (a) What is the traffic intensity for every user? (b) obtain the number of users that could use the system with 1% blocking if only 1 channel is available.


UNIT III
PART A
1. What are the 3 basic radio propagation issues?
2. Define Reflection.
3. Define Diffraction
4. Define scattering
5. Define Brewster angle
6. Calculate the Brewster angle for a wave impinging on ground having a permittivity of ?r
7. Define the term propagation models
8. List a few outdoor propagation models
9. List a few indoor propagation models
10. Define Fading or small scale fading.
11. What is frequency selective fading (OR) Doppler’s spread?
12. Define coherence time.
13. Define coherence bandwidth.
14. Why Raleigh distribution used in cellular system?
15. Write the free space propagation path loss formula
16. What is level crossing rate?
17. What is power delay profile?
18. Write few mathematical models used for delay profile.
19. What is flat fading?
20. Compare fast fading and slow fading.
21. Compare flat fading and frequency selective fading.
22. When Rice distribution is preferred than Rayleigh distribution in cellular system?
23. Write Rayleigh faded signal in formula form.
24. Define antenna gain

PART B
1. Derive the Free space path loss formula
2. Explain about Outdoor Propagation models.
3. Explain about Indoor Propagation models.

Earning:   Approval pending.