Delay Analysis of IEEE 802.11 Based Ad-Hoc Network Under Unsaturated Condition

摘要

Recently, IEEE 802.11 wireless ad-hoc networks become popular due to their flexibility and lack of infrastructure. Also they can easily be set up and almost available anywhere and anytime. Most researches which evaluate performance of these type of networks suppose saturation condition for the sake of analytical simplicity. However, most recent applications have ON/OFF property that causes unsaturation condition. In order to have that condition, each node is modeled by a M/G/1 Markov model and has Poisson distribution as its packet arrival model. Based on these assumptions, average and variance of service time are analyzed accurately. Delay as an important QoS parameter in time critical applications, is analyzed precisely in this paper. Computing service time variance ables us to evaluate average packet delay by Pollaczek-Khinchin equation. It also helps us to estimate probability density function of its service time. To prove our analytic results, extensive simulations have been done, which show that the analytical and simulation results match perfectly.