Analysis of contention-based multi-channel wireless MAC for point-to-multipoint networks

We analyze the delay performance of multi-channel MAC in point-to-multipoint wireless networks. We focus on contention based operation of nodes in such networks using a multi-channel MAC protocol adapted from Jungmin So et al., (2004). Our analysis can be extended to IEEE 802.11 DCF in PMP mode of operation and contention based IEEE 802.16 based networks. Using a slotted-time model, we derive expressions for the service time distribution of the packets, and approximate expressions for the queuing delay under Poisson traffic, when the contention window is of fixed size. We extend this analysis to incorporate exponential backoff of the contention window size. We conduct simulations for the multichannel MAC protocol in NS-2, and note that our analytical results match well with simulation results for moderate to high values of traffic intensity. Our analysis enables us to capture the imp act of various system parameters on queuing delay