Performance evaluation of IEEE 802.11e based on ON-OFF traffic model

We investigate the performance of the IEEE 802.11e while emphasizing on the end-to-end delay performance. In our MAC delay analysis, we are based on elementary conditional probabilities, avoiding the complex Markov Chains method. For a thoroughly study of the MAC delay, we take the Z-transform of the backoff duration in order to provide higher moments of the MAC delay distribution. The first moment corresponds to the mean MAC delay, while the second moment to the Standard Deviation of the MAC delay, which depicts the jitter. We also estimate the Probability Mass Function (PMF) of the MAC delay through the Lattice Poisson Algorithm. For the queuing delay, we consider a queue for each Access Category (AC) with one common server and an input process which is described by an ON-OFF model depicting the bursty nature of traffic. The service time follows the MAC delay distribution. Analyzing this queue, we provide results both for saturated and non-saturated channel condition. The end-to-end delay is estimated by the sum of queuing and MAC delay. The analytical results are validated through simulation.