CMC

1.a) With a neat diagram explain a basic cellular system.

b) Why is the mobile radio environment unique as compared to other forms of

wireless communication? [16]

2.a) How does frequency reuse technique increases spectrum efficiency in a cellular

system? Explain it with the help of suitable example which compares a cellular

mobile system with a conventional mobile system.

b) Why hexagonal cell shape is preferred over triangular or square cell shapes to

represent the cellular architecture? [16]

3.a) Define co-channel cell and co-channel interference. How does co-channel

interference become a serious concern in the design of a cellular mobile system?

b) Determine the signal-to-co-channel interference ratio C/I at the mobile receiver

located at the boundary of its omni directional operating cell, under the influence

of interfering signals from six co-channel interfering cells in the first tier in a

cellular system designed with

i) K = 7 ii) K = 9 iii) K = 12

Assume the path-loss exponent is 4. What would be the correct choice of K for a

system requiring C/I = 18 dB? [16]

4.a) What are the different types of non co-channel interference? Explain in detail.

b) How cell splitting improves the channel efficiency and discuss its types? [16]

5.a) Discuss the point-to-point transmission between the fixed stations over the water

and flat open land.

b) Explain the foliage loss with respect to mobile communication. [16]

6.a) Discuss the point-to-point prediction model to obtain path loss.

b) Discuss in brief about cell site antennas and mobile antennas. [16]

7.a) Compare the dynamic and static channel assignment.

b) Discuss the set-up channels and access channels w.r.t mobile communication.[8+8]

8. Write short notes on:

a) Hand-off mechanism

b) Leaky feeders. [8+8]