A Distributed Opportunistic Scheduling Protocol for Multi-Channel Wireless Ad-Hoc Networks

The topic of opportunistic scheduling for wireless ad-hoc networks has been studied for single-channel networks in several recent works. Since now many wireless systems provide multiple channels for data transmission, this problem is of practical interest for networks with multiple channels. In this paper, we study the problem of opportunistic scheduling for one type of ad-hoc networks where the wireless spectrum can be divided into multiple independent sub-channels for better efficiency. We start with a naive multi-channel protocol where the scheduling scheme is working independently from sub-channel to sub-channel. We show that the naive protocol can only marginally improve the system throughput. We then develop a protocol to jointly consider the opportunistic scheduling behavior across multiple sub-channels. We characterize the optimal stopping rule and present several bounds for the system throughput of the multi-channel protocol. We show that by joint optimization of the scheduling scheme across multiple sub-channels, the proposed protocol improves the system throughput considerably in contrast to that of single-channel systems.