Multi-Channel Ad Hoc Network with Asynchronous Channels

In this paper, we consider a simple but efficient medium access control (MAC) protocol that can be used in an ad hoc network with asynchronous multi-channel environments. The approach in our proposal is to use time offset between channels where each channel has its own frame starting time. We assume that the network runs in power saving mode (PSM) of the IEEE 802.11 standard protocol where the channel structure consists of beacon frame, ad hoc traffic indication message (ATIM) window, and data window. By asynchronizing the beacon frame start time between channels, some nodes that have no tasks involved in the current channel can switch to other channels for more data transmission trials. Through extensive simulations, we confirm that our multi-channel access scheme results in significant throughput enhancement compared to the access scheme using a single channel. Combining our proposal with some power saving scheduling algorithm, we can achieve much higher throughput. We verify that our analysis results are quite close to the simulation results..