Slotted ALOHA and CDPA: a comparison of channel access performance in cellular systems

The paper compares the performance of two channel-access schemes suitable for the cellular environment which, in particular allow the packet capture and can deal with inter-cell interference. The first scheme is the well known S-ALOHA while the second one is the capture division packetized access (CDPA). The comparison is analytically performed over a common system with a common analytical model. Despite the many analyses that have appeared on S-ALOHA, the one we develop is new because a throughput density uniformly distributed on the plane is considered in a multiple cell environment. The analysis clearly shows the effect of intra-cell and inter-cell interference on the ALOHA system and proves that a superior throughput is achieved by CDPA, which completely avoids intra-cell interference. Our analysis also provides an insight into the effectiveness of power control on both systems