Queuing Analysis of HCCA for Multi-Rate Wireless LANs with Truncated ARQ Protocol

In this paper, a novel queuing analytical framework is introduced to analyze the performance of the HCF controlled channel access designed as a medium access mechanism in wireless local area networks. The queuing model defines a multi-rate medium using adaptive modulation and coding which is a key point in wireless networks to increase effective transmission rate. Based on a MAP (Markovian arrival process)/PH (phase type)/1 queue with vacation and time-limited service, the model considers a limited node buffer and non-ideal channel with the automatic repeat request protocol. Using a MAP for traffic arrival process and PH distribution for packet service process, the inclusion of the non-transmission and vacation processes makes our analysis very general and comprehensive to support various types of practical traffic streams. To formulate the model, the powerful matrix-geometric method is employed, and the mutual impacts of some parameters in the MAC and the PHY layers are then evaluated to improve system performance. Finally, optimization of parameter settings to maximize throughput is discussed.