Traffic-aware channel assignment for multi-radio wireless networks

Abstract

This paper studies channel assignment in multi-hop wireless networks in which nodes are equipped with multiple radios, each of which can be assigned to a channel. We argue for an approach that first assigns channels independently of traffic, to achieve basic connectivity and support light loads such as control traffic, and then dynamically assigns channels to the remaining radios in response to traffic demand. The objective is to balance the need for a stable baseline topology and the desire to maximize throughput by dynamically adapting the topology to current network conditions. We call this a traffic-aware (TA) approach, in contrast to both traffic-independent (TI) and traffic-driven (TD) channel assignment and topology control schemes found in the literature. We formulate the problem as a two-stage mixed integer linear program (MILP), and find that our approach supports good connectivity and data rates comparable to those achieved with a TD channel assignment, while achieving lower resource utilization than TI approaches. We also quantify the tradeoffs involved in the decision of what proportion of radios to enable during the traffic-independent stage and what proportion to enable dynamically in response to changing traffic demands. © 2012 IFIP International Federation for Information Processing.