Performance evaluation 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. It is also known that the performance of PRMA is degraded when we consider the transmission of integrated voice and data. In this paper, we propose the use of adaptive array antenna with PRMA protocol to improve the performance. In the proposed model, the adaptive array can acquire a packet even when a collision occurs. First, we consider the voice traffic only and evaluate the throughput performance by the Markov analysis. We also evaluate the throughput and the packet dropping probability by the computer simulations. It is shown that the proposed model attains higher throughput and lower packet dropping probability than the conventional PRMA. Next, we consider the integrated voice and data traffic and evaluate the throughput, packet dropping probability and the data packet delay. It is shown that the proposed model can reduce the voice performance degradation caused by the additional data traffic.