Limiting performance of frequency-hop random access

The multiple-access capability of asynchronous frequency-hop packet-radio networks is analyzed. The only interference considered is multiple-access interference, and perfect side information is assumed. Bounds on the probability of error for unslotted systems are developed based on the distributions of the maximum and minimum interference levels over the duration of a given packet, and these are employed to develop corresponding bounds on the throughput. The idealized model makes possible the derivation of asymptotic results showing the convergence of these bounds for high traffic levels. The asymptotic performance of the system is seen to be the same as that of the corresponding slotted system. Results for the maximum asymptotic throughput are also obtained. These results show that the asymptotic sum capacity of the channel can be attained using Reed-Solomon coding. All these results are valid for either fixed or exponentially distributed packet lengths. The results indicate that the performance of frequency-hop networks is insensitive both to the distribution of packet lengths and to whether or not transmissions are slotted. It also demonstrates the efficacy of Reed-Solomon coding in combating multiple-access interference