Performance analysis of multicast polling based bandwidth request in IEEE 802.16 networks

In IEEE 802.16 networks, subscriber station (SS) can request bandwidth based on multicast polling of the base station (BS). In this way, SSs of the same group contend for the transmission opportunities (TOs) allocated by BS using a binary exponential backoff (BEB) algorithm. Different system parameters, such as polling group number and backoff parameters influence the delay of bandwidth request based on multicast polling. However, little attention has been paid to this problem. In this paper, we propose a mathematical model and compare the related simulation to analyze the delay of bandwidth request based on multicast polling. Simulation results reveal that the delay decreases when the polling group number increases especially in large-size network. At the same time, it also depends on TO number and backoff parameters.