Throughput-Delay Performance Analysis Of Ssma Packet Radio Network

Abstract

Multiple access communication accommodates a large population of relatively uncoordinated users of a common spectral allocation in the same and neighboring geographical areas with the number of simultaneous users proportional to various variable parameters. A continuous-time Markov chain model for an asynchronous spectrum packet radio network is presented. The network consists ofN fully connected nodes and the mobile users in all nodes are assumed identical. Packets arrive at each node and are re-transmitted when lost, according to Poisson processes with different rates and with packet lengths that are exponential in distribution. A simple threshold approximation is used to account for the multi-user interference and the preamble collision probability at receiving mobile users to account for the capture effect. Results obtained demonstrate the effects on throughput and packet delay performance of the network according to the variations of the network size, the packet re-transmission rate, the preamble collision probability at receiving mobile users, and the threshold value of the radio channel capacity. Further the approximate analysis results are very close to those obtained by computer simulations.