Wireless and Mobile Protocol

COSC4301/5340: Fund. Wireless and Mobile Prot.

Spring 2020

HOMEWORK I

QUESTION 1. By using geometric arguments, show that the co-channel reuse factor for cellular deployments based on hexagonal cells is given by D/R = sqrt(3N).

QUESTION 2. A new wireless service provider decided to employ a cluster of N=19 cells as the basic module for frequency reuse.

a) Can you identify one such cluster structure?

b) Repeat a) for N=28

c) Can you get an alternative cluster structure for part a)?

d) What is the reuse distance for the system of part c)?

e) Can you find the worst case co-channel interference in such a system?

QUESTION 3.

a) If you use an AMPS cell phone in GSM environment what minimum changes do you have to make so that you can communicate?

b) Why is a smart card needed in GSM and while not required for AMPS? Explain the logic behind this.

c) What is the frame size and the number of TDMA slots per frame in GSM and how does it compare with the IS-54 format?

QUESTION 4. The GSM system uses a 270.833 kbps data rate to support 8 users per frame.

a) What is the raw data rate provided fro each user?

b) If guard time, ramp up time, and synchronization bits occupy 10.1 kbps, determine the traffic efficiency for each user.

QUESTION 5. Why is the near far problem present in CDMA and not in FDMA?

QUESTION 6. Is the hidden terminal problem solved in IEEE 802.11? Explain the rational behind your answer.

QUESTION 7. Design a new location update scheme other than the movement-based, distance-based, and time-based schemes covered in the class. Briefly describe the location update and paging procedures of your new scheme.