Performance evaluation of mobile slotted ALOHA networks under different channel models-a simulation study

A simulation model is developed to compare the performance of mobile slotted ALOHA networks with linear topology (such as the communications from vehicles to base stations in the future Intelligent Vehicle Highway Systems) under different channel models. Typical mobile radio channels such as Rayleigh, Rician, Rayleigh with lognormal shadowing, and Rician with lognormal shadowing are considered and their throughput-delay performance are compared against each other. It is found that different channels have similar performance when data traffic load is light. The difference becomes more significant when load is heavy. Simulation results show that none of the 4 channels always has the best performance. An interesting phenomenon was found for the network configuration considered-when the network is overloaded, network throughput may first decrease and then increase as the load keeps increasing.