Throughput-delay improvement of unslotted CDMA packet radio networks using rate adaptive CLSP

Abstract

This paper presents the throughput-delay analysis or a centralized unslotted DS/CDMA packet radio network using rate adaptive channel load sensing protocol (CLSP). CLSP is an access control protocol used to limit the contentions of CDMA unslotted ALOHA radio channel under a certain threshold to improve the system throughput. The rate adaptive extension of CLSP is proposed (i) to compensate the near-far effects and power control difficulty of connectionless packet transmissions under changing channel conditions; (ii) to enhance the system performance and coverage. The analytical model is developed based on a multi-rate loss network model taking into account the impacts of spatial user distributions and radio propagation attenuation. The results show that the rate adaptive CLSP system gains significant improvement in throughput-delay tradeoffs compared to the fixed rate counterpart with the same coverage, offered traffic and QoS requirements.