MAC Layer Channel Access and Forwarding in a Directional Multi-Interface Mesh Network

The wireless mesh network is an emerging technology that provides high quality service to end users as the "last milerdquo of the Internet. Furthermore, multicast communication is a key technology for wireless mesh networks. Multicast provides efficient data distribution among a group of nodes. However, unlike other wireless networks, such as sensor networks and MANETs, where multicast algorithms are designed to be energy efficient and to achieve optimal route discovery among mobile nodes, wireless mesh networks need to maximize throughput. This paper proposes two multicast algorithms: the level channel assignment (LCA) algorithm and the multichannel multicast (MCM) to improve the throughput for multichannel and multi-interface mesh networks. The algorithms build efficient multicast trees by minimizing the number of relay nodes and total hop count distances of the trees. The algorithms use dedicated channel assignment strategies to reduce the interference to improve the network capacity. We also demonstrate that using partially overlapping channels can further diminish the interference. Furthermore, additional interfaces help to increase the bandwidth, and multiple gateways can further shorten the total hop count distance. Simulations show that those algorithms greatly outperform the single-channel multicast algorithm. We also observe that MCM achieves better throughput and shorter delay while LCA can be realized in distributed manner.

IEEE 802.11 Wi-Fi equipment based wireless mesh networks have recently been proposed as an inexpensive approach to connect far-flung rural areas. Such networks are built using high-gain directional antenna that can establish long-distance point-point links. In recent work, a new MAC protocol named 2P has been proposed that is suited for the interference pattern within such a network. However, the 2P protocol requires the underlying graph (for each 802.11 channel) to be bi-partite. Under the assumption that 2P is the MAC protocol used in the mesh network, we make the following contributions in this paper. Given K non-interfering 802.11 channels, we propose a simple cut-based algorithm to compute K bi-partite sub-graphs (on each of which the 2P protocol can be run separately). We establish the class of graphs that can thus be completely covered by K bipartite subgraphs. For the remaining set of graphs, we look into the price of routing all end-to-end demands over only the bipartite subgraphs. We analytically establish what fraction of the max flow of the original mesh-graph can be routed over the bipartite subgraphs. Finally we look into the problem of mismatch between the load on a link (as computed by max flow) and its effective capacity under a given channel allocation. We propose heuristics to cluster links with similar loads into the same bipartite graphs (channels) and through comprehensive numerical simulations show that our heuristics come very close to the best possible flow.

Wireless mesh networks (WMNs) are gaining significant momentum as a promising technology for the next-coming state-of-the-art wireless networking. Among many factors, the performance of WMNs would be largely affected by the properness of the deployed routing protocols and the efficient usage of wireless resources. Routing protocols are required to well capture WMNs' features while wireless channels should be used efficiently in order to accommodate high amount of traffics over the mesh backbone. Recently, a Tree-based Routing (TBR) protocol become a popular state-of-the-art proactive routing protocol and its tree-based broadcasting become an often used technique. Though TBR protocol is well-suited for WMNs' architecture and the skewed nature of traffic toward the root, the protocol in its current form faces issues which has to be addressed. Specifically, when some or all nodes are equipped with multiple radios, to reduce collision and co-channel interference, not only the parent-child relationship but also the sibling relationship need to be constructed by the TBR protocol in the multi-channel WMNs. In this paper, we propose a hybrid tree-based protocol for concurrent routing and channel assignment over WMNs. The protocol makes use of sibling links to mitigate the aforementioned shortcomings of TBR protocol. Moreover, in order to address high backbone traffic, the protocol integrates a receiver-based channel assignment scheme. The protocol efficiently deploys the parent-child topological relationships of nodes to enhance efficiency of broadcast transmissions over receiver-based multi-channel WMNs. Simulation results over NS-2 network simulator reveal that our proposed hybrid tree-based protocol achieves much higher performance than the utilization of the original receiver-based CA and TBR protocol.

Wireless mesh networks (WMNs) has been actively explored for a few years, and the IEEE 802.11 Task Group "s" has recently approved the active 802.11s standard for Wireless local area network (WLAN) mesh networking. To provide differentiated channel access and quality of service (QoS) guarantees for multimedia flows, IEEE 802.11s standard employs enhanced distributed channel access (EDCA) as the basic medium access control (MAC) protocol. In this study, the authors focus on modelling and analysing the medium access delay differentiation of EDCA under saturation condition in multi-hop WMNs. The authors develop a three-dimensional Markov chain model to evaluate the medium access delay differentiation of EDCA. In this model, the authors fully consider the performance impact of Request to Send (RTS) frame collisions and data frame collisions and then put forward the pseudo states to distinguish the different back-off procedures induced by these collisions. Using this analytical model, the authors derive the average medium access delay for the flows with different priorities. Comparisons with the simulation results show that the analytical model is extremely accurate.

IEEE 802.11-based backbone mesh networks comprise of static Wireless Mesh Routers (WMRs) which create a wireless multihop backbone to provide high-speed last-mile wireless Internet access to communities. Specialized WMRs called Gateways provide the interconnection between the mesh network and fixed IP networks. Mesh routers perform backhaul routing and may additionally serve as Access Points (APs) for clients. Their main task is to maintain backhaul mesh connectivity and find routes to gateways for clients. An important research problem which has received little attention is the optimal selection of gateway and the route to that gateway by mesh routers within the mesh backbone. We propose an efficient gateway and route selection scheme for backbone mesh networks which can be adopted for upcoming 802.11s mesh standard [1] with minimal changes. Gateway load, route interference and path quality metrics are used to select the best available gateway and the route to that gateway. Simulation results show improved performance compared to schemes using nearest gateway, gateway load metric or the ETX [2] metric for gateway selection.

This paper considers the problem of self-diagnosis of wireless mesh networks (WMNs) and mobile ad-hoc networks (MANETs) using the comparison approach. In this approach, the network consists of a collection of n independent heterogeneous mobile or stationary hosts interconnected via wireless links, and it is assumed that at most sigma of these hosts are faulty. In order to diagnose the state of the wireless mesh and ad-hoc network, tasks are assigned to pairs of hosts and the outcomes of these tasks are compared. The agreements and disagreements among hosts are the basis for identifying the faulty ones. We develop a new distributed self-diagnosis protocol, called adaptive-DSDP, for MANETs and WMNs that identifies both hard and soft faults in a finite amount of time. We analyze the time and communication complexities of our protocol and compare it to existing self-diagnosis protocols

Wireless multi-hop mesh network (Wireless Mesh Network, WMN), is a new network technology developed from mobile Ad hoc, widely used in the world. The paper carried out in-depth research and outlook to the key technologies, network architecture, performance and characteristics and typical application scenarios of Wireless Mesh Network.

Wireless Mesh Networks (WMN) are becoming inevitable in this world of high technology as it provides low cost access to broadband services. Moreover, the technologists are doing research to make WMN more reliable and secure. Subsequently, among wireless ad-hoc networking technologies, Bluetooth Low Energy (BLE) is gaining high degree of importance among researchers due to its easy availability in the gadgets and low power consumption. BLE started its journey from version 4.0 and announced the latest version 5 with mesh support capability. BLE being a low power and mesh supported technology is nowadays among the hot research topics for the researchers. Many of the researchers are working on BLE mesh technology to make it more efficient and smart. Apart from other variables of efficiency, like all communication networks, mesh network security is also of a great concern. In view of the aforesaid, this paper provides a comprehensive review on several works associated to the security in WMN and BLE mesh networks and the research related to the BLE security protocols. Moreover, after the detailed research on related works, this paper has discussed the pros and cons of the present developed mesh security mechanisms. Also, at the end after extracting the curx from the present research on WMN and BLE mesh security, this research study has devised some solutions as how to mitigate the BLE mesh network security lapses.

Millimeter Wave (mmWave) communication is considered as an enabling technology for the next generation of cellular networks because it offers much larger bandwidth and higher data rate than the current lower-frequency cellular systems to satisfy the exponential growth of mobile data demand. High gain directional antennas are needed to overcome high propagation losses in mmWave bands. However, the reliance on highly directional antennas will result in a more complicated initial cell search procedure since both base station and mobile device have to look for each other over a large space to establish the link. This paper focuses on analyzing the performance of the directional cell search procedure where the base stations periodically transmit signals in a set of optimal directional patterns to scan the coverage area. The mobile terminals detect the signals from the base station using the Generalized Likelihood Ratio Test (GLRT). The results show that with an appropriate scanning scheme, the use of directional antennas can outperform their omnidirectional counterparts in terms of signal detection performance as well as total time required.

Design and experimental performance analysis of a B.A.T.M.A.N.-based double Wi-Fi interface mesh network

Wireless mesh networking has trans pired as a gifted technology for potentialbroadband wireless access. In a communication network, wireless mesh network plays a vital role in transmission and are structured in a mesh topology. The coordination of mesh routers and mesh clients forms the wi reless mesh networks which are routed through the gateways.Wireless mesh networks uses IEEE 802.11 standards and has its wide applications broadband home networking and enterprise networking deployment such as Microsoft wireless mesh and MIT etc. A profes sional Qos provisioning in intra cluster packet level resource allocation for WMN approach takes power allo cation, sub carrier allocation andpacket scheduling. This approach combines the merits of aKarush-Kuhn-Tucker (KKT) algorithm and a genetic algorithm (GA) based approach. The KKT algorithm uses uniform power allocation over all the subcarriers, based on the optimal allocation criterion. The genetic algorithm is used to generate useful solutions to optimization and search problems and it is also used for search problems. By combining the intrinsic worth of both the approaches, it facilitates effective QOS provisioning at the packet level. It is conclude d that, this approach achieves a preferred stability between system implementation and computational convolution.

Wireless mesh networks have attracted increasing attention and deployment as a high-performance and low-cost solution to last-mile broadband Internet access. Network routing plays a critical role in determining the performance of a wireless mesh network. To study the best mesh network routing strategy which can maximize the network throughput while satisfying the fairness constraints, existing research proposes to formulate the mesh network routing problem as an optimization problem. These works usually make ideal assumptions such as known static traffic input. Whether they could be applied for practical use under the highly dynamic and uncertain traffic in wireless mesh network is still an open issue. The main objective of this paper is to understand the effects of traffic uncertainty in wireless mesh networks and consider these effects in throughput maximization routing. It identifies the appropriate optimization framework that could integrate the statistical user traffic demand model into a tractable throughput maximization problem. The trace-driven simulation study demonstrates that our algorithm can effectively incorporate the traffic demand uncertainty in routing optimization, and outperform the throughput maximization routing which only considers static traffic demand.

Wireless technology is emerging as a key technology for the future networks. Wireless mesh networks (WMNs) have emerged as an indispensable technology for deployment of wireless services for various applications in personal, enterprise, and metropolitan areas. Researchers are working actively in different fields of WMNs for providing better services. Routing protocols play a vital role in WMNs to provide reliable configuration and maintenance of topology of the network. Designing a suitable cost metric for routing protocols to provide quality links for data transmission is the backbone of WMNs. Many cost metrics have been proposed for WMNs and is still an active research topic as new performance metrics need to be discovered due to the dynamics of this field. This paper considers the genetic algorithm-based routing technique for WMN.We have studied the existing cost metrics and proposed a genetic algorithm technique for routing in WMN. To evaluate the genetic algorithm, and to determine the relative performance of the genetic algorithm in the context of routing in WMN, we carry out experiments on two test systems. We have evaluated the quality of the results produced by our algorithm with the traditional hop count metric results. Our results show that routing in WMN using genetic algorithm produces better results as compared to traditional hop count metric results. Finally, we carry out a detailed analysis of results, which help us in gaining an insight into the suitability of genetic algorithm for routing in WMN.

Software-Defined Networking (SDN) is a framework conceived to make network infrastructures more programmable and more easily manageable. We explore the integration of the latter in Wireless Mesh Networks (WMNs) through the design of an opportunistic and self-configurable SDN solution. Opportunistic to be able to cope with the intermittent connectivity and network partitioning and merging scenarios caused by the dynamic nature of the wireless medium; and self-configurable to be able to redirect dynamically SDN-enabled Wireless Mesh Routers (WMRs) to the most suitable SDN controller. This paper proposes mechanisms allowing to make automatic an SDN-based WMN deployment. Our proposed solution enables (1) for each WMR to discover the reachable SDN controllers, then to select and connect by itself to the most suitable one; (2) the setting up of new SDN controller(s) among the WMRs in case of controllers unavailability. We validated our work using NEON, an SDN solution developed by CEA LIST that supports fast devices configuration and services deployment in dynamic and unconfigured infrastructures contexts.

Wireless Mesh Network (WMN) is a multi hop low cost, with easy maintenance robust network providing reliable service coverage. WMNs consist of mesh routers and mesh clients. In this architecture, while static mesh routers form the wireless backbone, mesh clients access the network through mesh routers as well as directly meshing with each other. Different from traditional wireless networks, WMN is dynamically self-organized and self-configured. In other words, the nodes in the mesh network automatically establish and maintain network connectivity. Over the years researchers have worked, to reduce the redundancy in broadcasting packet in the mesh network in the wireless domain for providing reliable service coverage, the source node deserves to broadcast or flood the control packets. The redundant control packet consumes the bandwidth of the wireless medium and significantly reduces the average throughput and consequently reduces the overall system performance. In this paper I study the optimization problem in Wireless Mesh Networks. We have proposed a novel approach to reduce the broadcast redundant packet in the wireless mesh network. Also we have shown, a novel procedure to forward the control packet to the destination nodes and efficiently minimize the transmitted control packet in the wireless mesh cloud , that covers the domain.