Network Coding Based Link Scheduling for QoS Provisioning in Multi-radio and Multi-channel Wireless Mesh Networks

This paper addresses Quality-of-Service (QoS) improvement in wireless mesh networks (WMNs) with multi-radio multi-channel by applying a novel network coding technique. It is known that network coding over wired networks enables connections at rates that cannot be achieved by traditional routings. However, the properties of wireless networks (e.g., omnidirectional transmissions, destructive interference, single transceiver per node, finite energy) modify the formulation of network coding and deviate from the classical network coding approach used in wired networks. In this paper, we investigate the problem of network-wide data transmission under the consideration of QoS requirements (namely packet delivery ratio, packet delay) over multi-radio and multi-channel WMNs. To solve this problem, we first introduce a network coding method, namely COPE, which is used to increase network-wide throughput for unicast wireless networks, and then present an Integer Linear Programming formulation of a given multi-radio and multi-channel WMN for addressing network coding traffic, routing, QoS requirements and scheduling optimizations. The proposed analytical formulation increases the network-wide throughput while satisfying the generalized QoS requirements by combining network coding strategy and interference free schedules. Our evaluations both in 16-node graph topology and 32node random topology network show that a route selection strategy that is aware of network coding leads to higher in end-to-end throughput when compared to coding-oblivious routing strategies.