Performance evaluation of interference aware topology power and flow control channel assignment algorithm

Nowadays, multi-channel multi-radio wireless mesh networks are gaining more popularity as they have enormous applications like last mile broadband Internet connectivity, home networking, commercial and civilian applications. The performance of wireless mesh networks can be improved by the proper assignment of channels to multiple radios of a mesh node. Thus, channel assignment problem has significant importance. This paper presents the literature survey of various algorithms of channel assignment along with the advantages and limitations of each algorithm. Also, the paper gives the directions for future research work of channel assignment algorithms of wireless mesh networks.

Multi-channel communication in a Wireless Mesh Network with routers having multiple radio interfaces significantly enhances the network capacity. Efficient channel assignment is critical for realization of optimal throughput in such networks. In this paper, we investigate the problem of finding the largest number of links that can be connected with the overall network interference is minimized. Since the number of radios on any node can be less than the number of available channels, the channel assignment must obey the constraint that the number of different channels assigned to the links incident on any node is at most the number of radio interfaces on that node. The above optimization problem is known to be NP-hard. By presenting the theoretical model, the above task is formulated as a multi-objective problem, and then a novel channel assignment based on improved NSGA-II is proposed. Extensive empirical evaluations represent that the novel algorithm proposed in this paper can implement network connectivity with little interference rapidly and efficiently. To meet the actual demand in wireless mesh network, ns-2 simulations are used to demonstrate the performance potential of our channel assignment algorithms in 802.11-based multi-radio mesh networks.

Multiple channels can increase network capacity by transmitting traffic on different channels in an interference area. Channel assignment is a critical issue for the multi-channel scheme. In this paper, we propose a efficient distributed channel assignment algorithm using cross-layer approach for multi-radio multi-channel wireless mesh networks. This scheme seeks to assign distinct channel to each node along the same route, subject to a channel availability constraint. Nodes in two-hop neighborhood which belong to two different routes are assigned distinct channel too. Thus, interference along neighboring nodes which belong to same route and different route can be reduced. The proposed scheme combines channel assignment with reactive routing protocol. This scheme exhibits significantly lower communication, computation complexity than existing channel assignment schemes. Simulation results show that this proposed scheme can improve performance of the multi-radio multi-channel wireless mesh networks greatly.

Wireless mesh networks (WMN) are receiving increasing development, which configuration multi-radio multi-channel nodes to improve channel resources utilization in the network topology architecture and achieve increasing efficient on the network throughput. The main goal of channel assignment algorithms in multi-radio multi-channel wireless mesh networks is to minimize the overall interference and improve the aggregate network capacity while assuring the maintainment in the connectivity of the network. How to distribute the channel for each node to ratio interface in order to avoid the ripple effect and enhance network robustness while taking into account load balance and other performance indicators with the network medium. The article propose the channel assignment algorithm for multi-radio multi-channel wireless mesh networks based on the traffic flow of the link, which equitably distribute equalization for the business flow between nodes so that the distribution through the link on the flow of equal. The channel assignment improve network capacity by setting the value to reduce interference with the network overall interference.

Fairness-oriented routing algorithm joint with power control and channel assignment for multi-radio multi-channel wireless mesh networks

Recently, importance of wireless networks increased significantly. Wireless Mesh Networks (WMNs) are receiving growing attention and offer many advantages in terms of connectivity and reliability. Multicast communication is an important technology for wireless networks in which the same content of data should be delivered to a group of receiver nodes simultaneously. So multicast routing provides efficient data distribution among a group of nodes rather than other traditional unicast routing strategies. Here we focus on the Channel Allocation (CA) scheme which efficiently utilizes multiple wireless interfaces to achieve better throughput and improving the radio interference. This kind of problem has been proved to be NP-hard. Hence, solving the multicast channel assignment problem in MCMR WMNs will be more complicated than that of traditional networks. The research in this paper is aimed at improving the network performance for efficient joint channel assignment and multicast routing problem in MCMR WMNs by using the Q-learning scheme. We also implement our proposed channel assignment algorithm, and evaluate and compare its performance with LAMR. Simulations and experimental results demonstrate that QLMR outperforms the previous works in terms of achieved average throughput, average end-to-end delay, average packet delivery ratio and so on. We will evaluate the performance of the proposed scheme.

Systems with multiple channels and multiple radios per node have been shown to enhance throughput of wireless mesh networks (WMNs). Recently, network coding has also been proved to be a promising technique for improving network throughput of WMNs. However, the performance of network coding in the context of multicast, a form of one-to-many communication, in multi-channel multi-radio (MCMR) WMNs is still unknown. In this paper, we present analytical models for estimating the average end-to-end delay, throughput and packet delivery ratio of a network-coded multicast session in 802.11-based MCMR WMNs. The proposed models are then validated using numerical analysis and simulations. To the best of our knowledge, our work is the first that studies the performance of network-coded multicast in MCMR WMNs.

The performance of Multi-Channel Multi-Radio (MC-MR) Wireless Mesh Networks (WMNs) can be improved significantly with the increase in number of channels and radios. Despite the availability of multiple channels in several of the current wireless standards, only a few of them are non-overlapping and many channels are partially overlapped. In this paper, we formulate the joint channel assignment and flow allocation problem for MC-MR WMNs as a Mixed Integer Linear Program (MILP). Unlike most of the previous studies, we consider the case of using both non-overlapped and partially overlapped channels. We consider an objective of maximizing aggregate end-to-end throughput and minimizing queueing delay in the network, instead of the sum of link capacities, since the traffic characteristics of a multihop WMN are quite different from a single hop wireless network. Our formulation takes into consideration several important network parameters such as the transmission power of each node, path loss information, signal to interference plus noise ratio at a node, and frequency response of the filters used in the transmitter and receiver. We show by simulations that our MILP formulation makes efficient use of the spectrum, by providing superior channel assignments and flow allocations with the addition of partially overlapped channels, without the use of any additional spectrum.

In order to fully exploit the aggregate bandwidth available in the radio spectrum, future wireless mesh networks (WMN) are expected to take advantage of multiple orthogonal channels, where the nodes have the ability to communicate with multiple neighbours simultaneously using multiple radios (NICs) over orthogonal channels. Dynamic channel assignment is critical for ensuring effective utilization of the non-overlapping channels. Several algorithms have been proposed in recent years, which aim at achieving this. However, all these schemes inherently assume that the mesh nodes are well-behaved without any malicious intentions. A recent work has exposed the vulnerabilities in channel assignment algorithms. In this paper, a mechanism is proposed to secure the channel assignment algorithms, addressing the security vulnerabilities in the existing algorithms. The proposed mechanism successfully prevents the WMN from the recently exposed attacks. The simulation based experiments show the effectiveness of the proposed solution. The experiments also show that the incurred overhead because of security is negligible.

The wireless mesh network is a new emerging technology exploiting the advantages of multiple radios and multiple channels. In this paper we have studied the channel assignment problem which is to assign channels to links in the network, and aimed at minimizing the network interference so as to improve the network throughput. The channel assignment problem is proved to be NP-hard. In this paper, we have developed a new approach based on the particle swarm optimization (PSO) algorithm and a heuristic algorithm to solve channel assignment problem in multi-radio multi-channel wireless mesh networks. Meanwhile, the crossover operation is employed in the discrete particle swarm optimization (DPSO) algorithm to handle the discrete channel assignment problem. Experimental results have shown that the rate of interference in the DPSO algorithm descends by 67.67% compared with the Tabu-based algorithm when there are 12 channels and 5 radios. And the heuristic algorithm can also yield good solutions with good quality in both dense and sparse networks.

In this paper, a model for the static channel assignment in multi-radio multi-channel wireless mesh networks is proposed. We describe an interference model in wireless communication environment. The degree of detail in the model determines the accuracy of channel assignment. In many wireless mesh networks studies, the simplistic protocol interference model is adopted, but the model is usually not realistic and practical. Therefore, we construct a physical interference model and put forward a pure integer quadratic programming (PIQP) model to solve the channel assignment problem and maximize the capacity of wireless mesh networks. The feasibility and effectivity of the channel assignment solution are suggested by the results of simulation.

Several active queue management (AQM) schemes have been proposed to address the bufferbloat issue, a long network delay and performance degradation issue caused by excess buffering of packets in network nodes. The solutions proposed up to now, however, satisfy only a subset of the key network performance metrics, i.e., end-to-end throughput, throughput fairness, and delay, in 802.11s-based multi-radio multi-channel wireless mesh networks (MRMC WMN). In this letter, we propose FD-AQM, a fairness-aware delay-controlled AQM to satisfy all three key network performance metrics simultaneously in the 802.11s-based MRMC WMN. The proposed FD-AQM achieves the goal by adopting a per-queue drop interval which is recalibrated according to the average round-trip time of flows, and a drop decision mechanism which considers average throughput as well as target delay. Through simulations, we show that FD-AQM is superior to other AQM schemes in terms of throughput and fairness.

Multi-channel communication in a Wireless Mesh Network with routers having multiple radio interfaces significantly enhances the network capacity. Efficient channel assignment is critical for realization of optimal throughput in such networks. This paper addresses the channel assignment problem for multi-channel multi-interface (radio) wireless mesh networks. We focus on static wireless mesh networks where multiple non-overlapping channels are available for each wireless interface. In this network environment, our objective is to find a fixed channel assignment which maximizes the number of bidirectional links that can be activated simultaneously, subject to interference constraints. We present a mixed integer linear programming models for solving the fixed channel assignment problem with multiple radios. Detailed computational results are presented and discussed to validate the algorithm.

In classical channel assignment (CA) in Multi-Radio Multi-Channel (MRMC) Wireless Mesh Networks (WMNs), the number of available frequency channels is assumed to be fixed. Two links that are within the interference range of each other could be assigned the same frequency channel, causing co-channel interference that degrades the network throughput. The objective of this research is to develop a realistic CA method that finds the smallest number of frequency channels required for interferencefree communication among the mesh nodes (MNs) in order to achieve the maximum network throughput while maintaining fairness among the multiple network flows in a dynamic MRMC WMN.

Systems with multiple channels and multiple radios per node have been shown to enhance throughput of wireless mesh networks (WMNs). Recently, network coding has also been proved to be a promising technique for improving network throughput of WMNs. However, the performance of network coding in the context of multicast in multi-channel multi-radio (MCMR) WMNs is still unknown. In this paper, we present a comprehensive performance evaluation of network-coded multicast in MCMR WMNs using extensive simulations, realistic network settings and meaningful performance metrics such as throughput, file completion time, packet end-to-end delay, and packet delivery ratio under a wide range of scenarios.