Performance evaluation of ad-hoc WLAN by M/G/1 queueing model

The distributed coordination function (DCF) is specified for both ad-hoc and infrastructure network configurations in the IEEE 802.11 standard. In this paper, we present an analytic model for evaluating the performance at nodes in a DCF based ad-hoc network without the assumption of saturation condition made in previous works. We model each node as a discrete time M/G/1 queue and describe the distribution of the DCF virtual service time by means of probability generating function (PGF), and further, obtain the average packet queueing delay and response time. Three adjustable input parameters are the number of stations n, packet arrival rate λ, and average payload length E[P]. The analytical results are validated through extensive simulations, and it is shown that the model has significant high accuracy.