PERFORMANCE OF AN INTEGRATED VOICE DATA SYSTEM IN NONUNIFORM TRAFFIC LOW-EARTH-ORBIT SATELLITE COMMUNICATION-SYSTEMS

In some recent studies, the use of low earth-orbit satellites in vario us applications is considered, In all of these studies, uniform distri bution of traffic load is assumed, In this paper, the performance of a low earth-orbit satellite communication system which is designed to s ervice to two kinds of users; i.e., voice users and data users is esti mated. The distribution of population of these users is assumed to be nonuniform, According to the simulation results, it is shown that the nonuniformity in traffic affects the performance of the system by decr easing the signal quality at the satellite which has to service to pop ulated areas and increasing it superfluously at the satellite with not so populated service area, in a given period of time, By modeling the satellites during their movements, the change in signal quality while experiencing a peak of traffic load in their route is also determined , A modified power control method based on the amount of traffic load of each satellite is also examined and is shown that this method can m ake some performance improvements in signal quality, which is limited by special features of low earth-orbit satellite systems.