Wireless networks become part of daily life. Day by day, every hotel, mall, cafe, restaurant etc. are covered by wireless internet zones. Not only laptop computers and PDAs are used to connect to wireless networks, but also some of the new mobile phones are also equipped with wireless network cards to connect to the wireless access points to get high-speed Internet access. In order to extend the limited range of wireless access points, multiple access points are deployed to the zones to compose wireless mesh networks. A wireless mesh network is a type of wireless ad hoc network which consists of mesh routers and mesh clients. Mesh routers are usually stationary and they form the backbone of the WMNs, while serving as access points for mesh clients, which can be stationary or mobile. Some of the routers act as Internet gateways to provide Internet access to the clients in the WMN.
Other routers contain additional multi-hop routing capabilities to forward packets to reach their destinations. WMNs are used as wireless backbones in campuses, enterprises and by ISPs to provide last-mile Internet access to users. In order to communicate with other mesh routers, routers should use common channels. However, traditional wireless routers are equipped with single wireless network interface card (NIC), therefore whole network uses only one channel.
Furthermore, in multi-hop settings throughput decreases significantly with increasing number of nodes and hops. Therefore improving throughput is a major concern in WMN research. IEEE 802.11 standards define 12 and 3 non-overlapping frequency channels for
802.11a and 802.11b/g respectively which can be used simultaneously to increase the aggregate bandwidth. However, this available bandwidth cannot be used by wireless mesh networks without any hardware or software modification on the routers. There are several approaches to use multiple channels to increase the throughput of the WMN. These approaches can be categorized by the number of radios used by each router.
A Wireless Mesh Network is a type of wireless ad hoc network which consists of wireless mesh routers and wireless mesh clients. Each router in the network operates as a host to its clients, serving as a gateway/bridge to forward their data like conventional access points. Moreover, routers are capable of forwarding other routers' traffic to support multi-hop communication and they construct the...