Wireless Mesh Networks (WMN) with multiple radios and multiple channels are expected to resolve the capacity limitation problem of simpler wireless networks. However, optimal WMN channel assignment (CA) is NP complete, and it requires an optimal mapping of available channels to interfaces mounted over mesh routers. Acceptable solutions to CA must minimize network interference and maximize available network throughput. In this paper, we propose a CA solution called as cluster-based channel assignment (CBCA). CBCA aims at minimizing co-channel interference yet retaining topology through non-default CA. Topology preservation is important because it avoids network partitions and is compatible with single-interface routers in the network. A 'non-default' CA solution is desired because it uses interfaces over different channels and reduces medium contention among neighbors. To the best of our knowledge, CBCA is a unique cluster-based CA algorithm that addresses topology preservation using a non-default channel approach. The main advantage of CBCA is it runs in a distributed manner by allowing cluster heads to perform CA independently. CBCA runs in three stages, where first the WMN nodes are partitioned into clusters. The second stage performs binding of interfaces to neighbors and third stage performs CA. The proposed algorithm improves over previous work because it retains network topology and minimizes network interference, which in turn improves available network throughput. Further, when compared with two other CBCA algorithms, CBCA provides better performance in terms of improved network interference, throughput, delay, and packet delivery ratios when tested upon network topologies with various network densities and traffic loads. Copyright 1863 of traffic follows a gateway-oriented traffic pattern. In enterprise networks, the peer-to-peer traffic pattern dominates. WMNs and CA solutions must cater to both types.A WMN has multiple frequency channels and MRs are equipped with multiple radio interfaces, and mesh clients are usually equipped with a single-radio interface [2]. Use of multiple radios and channels allows MR to transmit and receive simultaneously as well as communicate with multiple neighbors simultaneously [3]. So, WMN are often refered to as multi-radio multi-channel (MRMC) communication networks [4]. MRMC systems have better utilization of radio spectrum as compared with single-radio single-channel systems (SRSC) [5]. However, this performance improvement is possible if channel assignment (CA) provides efficient mapping between channels and available interfaces at every node (we refer to a router as either a node or a vertex and a radio link is called an edge). A CA solution must address the key issue of how to map channels to links in a way that minimizes interference and maximizes the capacity.In general, CA algorithms can be classified using several attributes such as centralized, distributed, default channel approach, non-default channel approach, varying default channel approach, topology control...
