Delay and Throughput Analysis of Prioritized EDCA in Latency-Sensitive Wi-Fi 8 Networks
Wi-Fi 8 introduces Prioritized EDCA (P-EDCA) to support latency-critical traffic within which DS-RTS/CTS operates as a two-phase channel access procedure. In this mechanism, stations first compete in a Defer Signal (DS) contention, which determines the number of stations entering RTS/CTS contention, creating a stochastic coupling not captured by existing IEEE 802.11 models. We develop an analytical framework for the performance analysis of DS-RTS/CTS using a 2-D Markov chain to model the RTS backoff process of a tagged station under a variable number of contenders. Using this model, we obtain expressions for head-of-line delay and normalized throughput. We further formulate an optimization problem for adaptive selection of the DS contention window size. Results show that a moderately sized DS contention window achieves a favorable throughput-delay trade-off across network densities.