Performance of a frequency hopping CSMA packet radio network

A frequency-hopping (FH), carrier sense-multiple access packet radio communications system is modeled with a random polling system. Each user in the network, whether mobile or fixed, is assigned a network FH code. All stations that have messages waiting to be transmitted monitor the radio channel for activities. When the channel becomes idle, all busy stations will transmit the FH synchronization pattern and try to seize the channel. The reason for having one successful transmission despite the collisions due to multiple transmissions is that once a receiver is locked on to a FH pattern, time-delayed versions of the same FH pattern appear as noise and are ignored. Despite the vast amount of research results on polling, there is very little known analytically about random polling systems. Expressions for bounding the average message delay, and simulation results to illustrate the tightness of the bounds are presented. Based on simulation results, upper and lower bounds on the mean message delay for nonuniform offered loads in a N-station network are obtained.<>