Wireless mesh network

About: Wireless mesh network is a research topic. Over the lifetime, 13600 publications have been published within this topic receiving 221035 citations. The topic is also known as: WMN.

Congestion Control and Channel Assignment in Multi-Radio Wireless Mesh Networks

Abstract: We address the problem of congestion control in multi-radio, multi-channel, wireless mesh networks. Compared to its single radio counterpart for which solutions exist, this problem is significantly more complex because it requires the radio channel assignments and the traffic allocations per channel be jointly optimized. We address the problem by introducing a formulation that allows its decomposition in two subproblems: A congestion control subproblem for traffic allocation to a fixed channel assignment over a node path and a discrete combinatorial channel assignment subproblem. We solve the conditional congestion control subproblem by mapping it to an optimization problem of traffic distribution to a set of radio paths. The solution provides channel congestion information that is utilized to address the channel assignment subproblem. This leads to an iterative procedure which guarantees successive increases to overall network utilization. Compared to existing work on multi- radio, multi-channel mesh networks, we show that our approach can yield significant gains both in terms of network utilization and establishing fairness.

Channel Assignment for Throughput Optimization in Multichannel Multiradio Wireless Mesh Networks Using Network Coding

Abstract: Compared to single-hop networks such as WiFi, multihop infrastructure wireless mesh networks (WMNs) can potentially embrace the broadcast benefits of a wireless medium in a more flexible manner Rather than being point-to-point, links in the WMNs may originate from a single node and reach more than one other node Nodes located farther than a one-hop distance and overhearing such transmissions may opportunistically help relay packets for previous hops This phenomenon is called opportunistic overhearing/listening With multiple radios, a node can also improve its capacity by transmitting over multiple radios simultaneously using orthogonal channels Capitalizing on these potential advantages requires effective routing and efficient mapping of channels to radios (channel assignment (CA)) While efficient channel assignment can greatly reduce interference from nearby transmitters, effective routing can potentially relieve congestion on paths to the infrastructure Routing, however, requires that only packets pertaining to a particular connection be routed on a predetermined route Random network coding (RNC) breaks this constraint by allowing nodes to randomly mix packets overheard so far before forwarding A relay node thus only needs to know how many packets, and not which packets, it should send We mathematically formulate the joint problem of random network coding, channel assignment, and broadcast link scheduling, taking into account opportunistic overhearing, the interference constraints, the coding constraints, the number of orthogonal channels, the number of radios per node, and fairness among unicast connections Based on this formulation, we develop a suboptimal, auction-based solution for overall network throughput optimization Performance evaluation results show that our algorithm can effectively exploit multiple radios and channels and can cope with fairness issues arising from auctions Our algorithm also shows promising gains over traditional routing solutions in which various channel assignment strategies are used

Max-Min Fair Capacity of Wireless Mesh Networks

Abstract: The use of WMNs as backbone for large wireless access networks imposes strict bandwidth requirements It is therefore necessary to study and quantify the capacity of such systems In this paper, we argue that the capacity of WMNs should be addressed in the context of fairness to ensure proper operation of WMNs Among the fairness schemes, max-min fairness allows fair and efficient use of network resources We therefore propose an algorithm for max-min capacity calculation, formulated in term of collision domains In addition, we show how to calculate the effective load of collision domains, assuming IEEE 80211 as the MAC protocol We illustrate our proposed algorithm and validate our results over baseline and general topologies

Topology control of ad hoc wireless networks for energy efficiency

Abstract: In ad hoc wireless networks, to compute the transmission power of each wireless node such that the resulting network is connected and the total energy consumption is minimized is defined as a Minimum Energy Network Connectivity (MENC) problem, which is an NP-complete problem. In this paper, we consider the approximated solutions for the MENC problem in ad hoc wireless networks. We present a theorem that reveals the relation between the energy consumption of an optimal solution and that of a spanning tree and propose an optimization algorithm that can improve the result of any spanning tree-based topology. Two polynomial time approximation heuristics are provided in the paper that can be used to compute the power assignment of wireless nodes in both static and low mobility ad hoc wireless networks. The two heuristics are implemented and the numerical results verify the theoretical analysis.

Multipath TCP with Network Coding for Wireless Mesh Networks

Abstract: In wireless multihop networks, techniques such as multipath, local retransmissions and network coding have been successfully used to increase throughput and reduce losses. However, while these techniques improve forwarding performance for UDP, they often introduce side effects such as packet reordering and delay that heavily affect TCP traffic. In this paper we introduce CoMP, a network coding multipath forwarding scheme that improves the reliability and the performance of TCP sessions in wireless mesh networks. CoMP exploits the wireless mesh path diversity using network coding, performs congestion control and uses a credit-based method to control the rate at which linear combinations are transmitted. CoMP uses a simple algorithm to estimate losses and to send redundant linear combinations in order to maintain the decoding delay at a minimum and to prevent TCP timeouts and retransmissions. We evaluate CoMP through extensive simulations and compare it to state-of-the-art protocols. We show that CoMP not only achieves a higher throughput, but also is more efficient than existing protocols, making TCP sessions feasible for wireless mesh networks even under heavy losses.