M-Polar: Channel Allocation for Throughput Maximization in SDR Mesh Networks

In traditional wireless networks, nodes use only a single channel per radio interface, thus limiting the overall channel diversity of the network. This restriction is due to the inherent limitations of commercially-available RF devices. With the advent of high bandwidth software-defined radios (SDRs), we now have the option of assigning multiple contiguous, independent channels to a single wireless interface. This new-found opportunity raises an important question: how do we assign contiguous channels to nodes in order to maximize overall network throughput? This question lies at the often-ignored intersection of single-radio-multi-channel and multi-radio-multi-channel assignment schemes. In this paper, we develop a protocol that assigns contiguous channels with the goal of evenly spreading the load across the multiple channels. Neighboring nodes greedily adjust their channel ranges according to channel conditions to achieve an overall pattern of partially-overlapping bandwidths that maximizes the network throughput. The end-result is a network that can dynamically adapt its bandwidth usage to the network load and the conditions of the different channels. The proposed protocol is evaluated with a prototype built upon the USRP as well as with detailed simulation.