Virginia Tech

Department of Computer Science

CS6504 Mobile Computing

Spring 2007

Homework 2 (Total 35 pts)

Due in class on Wednesday February 14^th, 2007

Q1. (5 pts) Draw a cell pattern with a frequency reuse factor of 3.

Q2. (10 pts) What percentage is the average power received from a transmitter in an indoor environment (a = 3.5) at a distance 3d as compared to the average power received at distance d.

Q3. (5 pts) Explain what is meant by channel locking in the context of channel allocation schemes.

Q4. (15 pts) PSS99

a) Explain the necessity of informing neighboring cells about the identity of the channel being chosen for transfer.

b) Consider step 4 of the algorithm presented on page 11. The MSS is waiting for REPLY messages from each of its neighbors. Do you agree or not with such design decision (explain your answer)? If not, propose a solution to improve the algorithm design concerning this issue.