Access control techniques for CDMA ALOHA

This paper is concerned with CDMA applied to packet radio communications, namely CDMA ALOHA. We focus our attention on access control protocols of CDMA ALOHA and discuss their throughput performance. We deal with four kinds of protocols; channel load sensing protocol (CLSP), modified CLSP (MCLSP), packet retransmission protocol (PRC) and optimal access control protocol (OACP). As a result, we found that if the access timing delay is relatively small, CLSP achieves a good throughput. However, degradation is found in the presence of access timing delay. Both MCLSP and PRC achieves the same throughput and they are robust to access timing delay. As for OACP, it shows superior throughput when the access timing delay is small yet shows robustness to access timing delay