A Joint Radio and Channel Assignment (JRCA) Scheme for 802.11-Based Wireless Mesh Networks

Wireless mesh network (WMN) is a promising tech- nology for broadband Internet access due to its low cost, ease of deployment, increased coverage, and robustness. Equipping each mesh router with multiple radios can greatly improve the capacity of WMNs since the radios at each node can simultaneously transmit data on orthogonal channels. Channel assignment is an important problem in multi-radio multi-channel WMNs where the goal is to assign a channel to each radio so that the resulting network topology is connected and the network capacity is maximized. Various channel assignment schemes assume that the number of radios at each node is given, but how this number is determined is not specified. In this work, we propose a Joint Radio and Channel Assignment (JRCA) algorithm that determines the number of radios required at each node based on the traffic demand and produces the channel assignment for each radio to minimize the interference among the links operating on the same channel. Thus, our algorithm can produce a network configuration that meets the customer demand and maximize the network capacity. Simulation results show that JRCA can achieve higher throughput with fewer radios at the network nodes, compared to fixed-radio WMNs. In addition to this, we believe that our work, to our best knowledge, is the first of its kind that couples the problem of radio allocation and channel assignment in a joint manner. I. INTRODUCTION IEEE 802.11-based Wireless Mesh Networks(WMNs) have become a key area of scientific research due to their diverse capabilities and lucrative advantages(1)(2)(3). An issue fac- ing such WMNs is the availability of substantial bandwidth required to support consumer's demands. Common wireless mesh implementations typically use commodity hardware equipped with a fixed number of radios that are sometimes inadequate to support client traffic demands. By simple obser- vation, a workaround would be to equip each mesh node with certain number of radios depending upon the net demand at the mesh nodes. However, this approach only solves a small part of the bigger problem. In addition to allocating radios to each of the nodes, one must also provide a suitable channel assignment of channels to all the radio interfaces so as to ensure network connectivity between the mesh clients and the Internet. Due to the well-known problem of channel interference, unwise channel assignments can negatively offset the advantage of increased bandwidth attained through the use of multiple radio interfaces. Henceforth, one needs to come up with a clever scheme to determine the right number of radio interfaces and their respective channel assignments for each mesh node, in order to ensure that the total bandwidth available does indeed meet the client's demands. In light of the aforementioned facts, this work aims at developing a novel scheme to allocate both radios and their respective channels with a goal of satisfying consumer's traffic needs. In this work, we propose a Joint Radio and Channel Assignment (JRCA) scheme, which is a novel technique of intelligently allocating radios and their respective channel assignments to wireless nodes in a mesh network with the in-