Anna University Chennai 2011-8th Sem B.E Electronics & Communication Engineering Electronics & Communication Engineering /B.Tech EMR/EMR , ester, Electronics and Communication Engineering, EC1

PART-A
(10*2=20)

1. describe the frequency reuse concept in mobile communication.

2. elaborate the advantages of cell splitting?

3. What is trunking efficiency?

4. describe coherence time. What is its significance?

5. What is the need for equalization in in mobile communication?

6. describe Brewster angle.

7. What is the function of vocoders?

8. What is the frequency in forward and reverse link of GSM and IS-95?

9. describe DECT.

10. elaborate the feature of 3rd generation wireless networks?


PART-B
(5*16=80)

11.(a) With the help of timing diagram discuss how a call is made from 1 cellular subscriber to a different cellular subscriber. (16)
Or
(b) discuss the techniques adapted to increase the channel and system capacity. (16)

12.(a)(i) discuss about Diffraction in Mobile Radio Propagation with the help of Knife Edge Diffraction model. (8)
(ii) Prove with necessary formula that envelope of a faded channel is Rayleigh distributed. (8)
Or
(b)(i) elaborate the kinds of small scale model? discuss every model in detail. (8)
(ii) What is Handoff? discuss the different Handoff techniques. (8)

13.(a)(i) A hexagonal cell four cell cluster has a radius of 1.38 km. A total of 60 channels are used in the system. If the loaded per user is 0.03 E and rate of arrival of calls is one per hour, compute the number of users per square if GOS is 5%. (8)
(ii) discuss time, frequency, space and polarization diversity techniques and compare them. (8)
Or
(b)(i) discuss linear equalization technique. (8)
(ii) define the performance of the orthogonal frequency division multiplexing. (8)

14.(a)(i) discuss about linear predictive coders, what is the significance of coders?
(ii) Write short note on GSM codec. (8)
Or
(b) discuss how the TDMA, CDMA and FDMA are used in wireless mobile communication. (16)

15.(a)(i) discuss the architecture of GSM. (8)
ii) Write short notes on WLL and Blue tooth. (8)
Or
(b)(i) Compare the 2G and 3G standard's of mobile communication. (8)
(ii) discuss about AMPS technology. (8)

Earning:   Approval pending.