Bounds and Asymptotic Results for the Performance of Asynchronous Frequency-Hop Packet Radio Networks

摘要

This research is concerned with the throughput performance of fully connected asynchronous frequency-hop packet radio networks. The performance of such networks depends on several factors, but the emphasis in this study is on the effect of the multiple-access interference on system performance. It is assumed, therefore, that there is no other interference on the channel and that perfect side information is available. The frequency hop channel is thus modeled as an erasures-only channel, and bounded distance erasures-only decoding is used. Using the above model, bounds on the error probability are developed, which yield corresponding bounds on the throughput. These bounds are shown to be asymptotically tight at high traffic levels for networks with an infinite population and Poisson traffic. The performance of the unslotted network considered is seen to be asymptotically the same as that of an equivalent slotted network for high traffic levels. It is also shown that the capacity of the channel can be attained using Reed-Solomon coding. These results are valid for both fixed and exponentially distributed packet lengths (the two most commonly used models). For networks with a finite population, bounds on the performance are derived for systems with binomial traffic and fixed-length packets. A more complicated analysis is required for Poisson traffic, since the effect of queuing of packets at each terminal is considered. Bounds and approximations on the throughput are developed for fixed and exponentially distributed packet lengths, and some representative numerical results are presented.