A topology preserving cluster‐based channel assignment for wireless mesh networks

Abstract

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...

Review of channel assignment approaches in multi-radio multi-channel wireless mesh network

“…In the topology preservation approach, all links on the single channel wireless mesh network logical topology are preserved on the feasible channel assignment solution [39,53,54,65]. In case of topology preserving, the routing protocols which are fully researched of the single channel routing protocols can be applied to the WMN without further modification.…”

“…The channel interference metric can be categorized into four types -interference-aware, traffic-aware, capacity/data rate-aware, QoS-aware and throughput-aware. Many CA approaches [14,17,18,22,27,[45][46][47][48][49][50][51][52][53][54] efficiently address inter-flow interferences in their channel interference index. However, only few research studies address the impact of the interference caused by the hidden nodes [27,55], multi-rate link sharing problem [12,13,44] and external interference [22,47] on the channel throughput in their channel interference index.…”

“…A semi-static cluster-based channel assignment approaches named ComTac [47] and CBCA [54] have been proposed to minimize the aggregated interference and maintain the node connectivity. The approaches comprise of two stages: clustering and channel assignment.…”

Stub Wireless Multi-hop Networks using self-configurable Wi-Fi Basic Service Set Cascading

“…In addition, these approaches limit the spectrum available for data exchange purposes. Hybrid approaches have also been proposed, such as [8] that uses a centralized clustering algorithm with distributed CA. Clustering approaches may be a good option for large-scale networks, however, they bring significant configuration complexity.…”

Design of logical topology with K‐connected constraints and channel assignment for multi‐radio wireless mesh networks

“…In WMNs consisting of single-radio single-channel nodes, the network capacity is significantly limited by nodal interference [3]. As highlighted in [3], the use of multi-radio multi-channel (MR-MC) enabled WMN is an effective approach for improving the network capacity. In this context, considerable state-of-the-art channel assignment schemes have been proposedlinear programming.…”