A Simple Performance Model of IEEE 802.11 WLAN with Arbitrary Buffer Size and Traffic Load

In literature, most existing performance models of the IEEE 802.11 networks assume a saturated traffic load, where every station always has a frame to send. Some other models capture a specific case of an unsaturated traffic load, where each station can buffer at most one frame at a time. There are, however, few works that model the performance for an arbitrary traffic load and buffer size using a three-dimensional Markov chain. But those models are very complex due to the huge number of transitions between the states with different queue sizes. In this work, we propose a new and much simpler performance model for arbitrary traffic loads and buffer sizes. The model is based on a very simple but valid assumption, which decreases the number of transitions in a three-dimensional chain, making it more readable and easier to calculate. The performance evaluations show that the proposed model has better accuracy than other well-known models under both unsaturated and saturated traffic loads.