IEEE 802.11 Packet Delay - A Finite Retry Limit Analysis

TLDR

This paper studies packet delays in IEEE 802.11 DCF MAC, examining how retransmission delays with or without retry limits affect performance. The authors develop a Markov‑chain analytical model that yields closed‑form expressions for packet delays, discard probability at the retry limit, and drop time for both basic and RTS/CTS access mechanisms. The model predicts packet delay and discard metrics across varying contention station counts, and simulation results confirm its accuracy.

Abstract

The contribution of this paper is on the study of packet delays for the IEEE 802.11 wireless local area network DCF MAC protocol. A method is presented capable of taking into account retransmission delays with or without retry limits. We present an analytical model based on a Markov chain which allows us to derive closed form expressions for the packet delays, the probability of a packet being discarded when it reaches the maximum retransmission limit and the average time to drop such a packet for the basic and RTS/CTS access mechanisms. The results presented are for standard protocol parameters versus the number of contention stations. Finally, the accuracy of the analytical model is verified by simulations.