Performance analysis of a token based MAC protocol with asymmetric polling strategy (`TOPO´) for indoor radio local area networks under channel outage conditions

A MAC (media access control)-protocol for the indoor radio environment has to be able to overcome individual link failure due to channel outage with a minimized wastage of bandwidth. `TOPO´, a token based MAC protocol with asymmetric polling strategy, is suggested for a network in which the allocation of common resources, such as bandwidth, is administered by a central station. The protocol supports different traffic types and services as well as the adaptation to varying load and changing channel characteristics. The performance parameters, mean response time and bandwidth utilization, are derived from simulations for the case of asynchronous file transfer. The simulation model incorporates channel outage of variable length and probability. The optimum packet size is determined for different nonfade durations