Performance analysis of reservation random access protocols for wireless access networks

摘要

A key issue in future wireless access networks is the design of multiaccess protocols that enable dispersed voice and data terminals to efficiently share the terminal-to-base radio channel. A promising class of multiaccess protocols for wireless access is that of reservation random access (RRA) protocols, in which voice talkspurt packets and data packets are statistically multiplexed over TDMA frames. Voice terminals obtain reservations for their talkspurts using a random access protocol. An analysis method for evaluating the performance of a class of RRA protocols is developed. The method is based on a Markovian model, whose stationary solution is obtained via an iterative computational procedure based on matrix decomposition techniques. Subject to a maximum delay constraint, the voice packet dropping rate and distribution of the number of packets dropped from a talkspurt are evaluated for three RRA protocol examples, and comparisons are made with the performance of an ideal hypothetical multiplexer. The transient performance of RRA protocols is evaluated by simulating their response to sudden changes in the number of active voice terminals. Finally, suggestions for the design of integrated voice/data RRA protocols are made.