Performance analysis of packet reservation multiple access with an adaptive array

For local wireless communications, the packet reservation multiple access (PRMA) protocol, which combines random access with time division access, has been proposed and analyzed. The study results shows that the performance of PRMA is degraded in the heavy load condition because of the contention mechanism of random access. We propose the use of an adaptive array antenna with the PRMA protocol to improve the performance. In the proposed model, the adaptive array can acquire a packet by pointing the peak antenna pattern toward that packet even when a collision occurs. We evaluate the throughput performance by a theoretical analysis. We also evaluate the throughput and the packet dropping probability by computer simulation. It is shown that the proposed model attains a higher throughput and lower packet dropping probability than the conventional PRMA.