Optimal arrival-time distribution for delay capture in spread-spectrum packet radio networks

The optimal arrival-time distribution that maximizes the delay-capture probability in spread-spectrum packet radio networks is derived. It is shown that using the optimal arrival-time distribution, the capture probability converges to a finite value as the number of contending users increase. Normalized throughput and average delay is computed for slotted ALOHA random access packet radio networks employing direct-sequence spread-spectrum modulation. I t is shown that large performance improvements may be expected by optimizing the arrival-time distribution compared to the uniform arrival-time distribution assumed by Davis and Gronemeyer [I]. Three practical realizable modifications are considered which are shown to provide performance close to the optimum.