Channel Assignment Protocols for Multi-Radio Multi-Channel Wireless Mesh Networks

The increasing demand for large and low cost wireless coverage, ranging from campus to city wide areas, has motivated a high interest in multihop communications with Wireless Mesh Networks (WMN) based on IEEE 802.11s as the most recent and significant standard. Channel Assignment (CA) is a mechanism which selects the best channels for an individual wireless node or the entire network aiming to increase the capacity of the network. Channel assignment has been extensively researched for multi-radio WMNs, but it is still very challenging when it comes to its implementation. Although IEEE 802.11s introduces new interworking, routing and wireless frame forwarding at the link layer, the multi channel architecture receives less attention due to many unsolved challenges that arise while mesh service set works over multiple frequencies. This research work tries to give a solution to the needs of designing an efficient channel assignment mechanism. As a result we have proposed a new static channel assignment based on the fact that not all wireless links are practically useful. Our mechanism prunes the network topology by removing weak wireless links and improves the network performance by reaching a more diverse channel-radio assignation solution. Toward designing a distributed channel assignment we propose a new game theory based formulation of channel assignment which is applicable to a realistic scenario with imperfect information at each router. We have proposed a distributed and hybrid channel assignment protocol based on the game formulation. The proposed channel assignment makes wireless routers to be able to follow the unpredictable changes in the wireless environment. We also investigated the types of channel assignment protocols which can be adapted to the IEEE 802.11s based mesh network and improve the network good-put in terms of data delivery ratio and end-to-end delay.