A strategy for mesh client mobility support in wireless mesh networks

Wireless Mesh Network (WMN) is recently emerged network having robustness. It supports clients to communicate with different types of networks, Internet etc which provides a better service to next generation. It consists of mesh routers and mesh clients. These mesh routers are minimal mobile and mesh clients are totally mobile. The protocols of Ad hoc network are used in WMN. These protocols assume that every node is mobile. But as the mesh routers are minimal mobile or not mobile, the protocols brings overhead for the mesh routers. Our task is to relieve mesh routers using ad hoc network protocol from the overhead and define a better protocol which will fit in WMN efficiently. To do so, we've found that the existing architecture of WMN is needed to be changed slightly. We have proposed a new architecture for Wireless Mesh Network. In our proposal WMN is relieved from overhead being caused by using ad hoc network protocol. Our architecture use unicasting technique in lieu of broadcasting technique for route discovery as well as route maintenance. We will first describe the overview of WMN, its existing architecture. Later we will go to our proposed architecture.

The provision for addressing multiple destinations in group multimedia application delivery over Wireless Mesh Networks (WMN) can be achieved efficiently via multicasting while considering the mobility of Mesh Clients (MC). One of the prominent components of WMN is the Internet Gateway (IGW) which provides wired bridge connection between the backbone network and the Internet. In addition, its cost is significant therefore its placement is one of the main determinants of the overall performance and deployment cost of WMN. This current work explores IGW placement or deployment optimisation for the purpose of incorporation of multicasting and mobility management. Thus, the main focus in this work centres on investigating IGW placement optimisation with the intent of extracting the design issues to answer questions on the appropriateness of the problem formulation and modeling techniques for the optimisation problem. Furthermore, the paper develops the sketch of modeling and formulation of IGW placement problem with the objective of optimising IGW placement while cost of multicast tree and mobility are optimised. This formulation is different from existing works which considers only geographic positioning, load-balancing and interference-based placement. This novel formulation will serve as the basis for IGW placement and selection algorithm to address IGW deployment problem in a mobile multicast WMN architecture.

Wireless mesh network (WMN) is considered as one of most emerging field for the research work in today's networking area due to its various approaches available to handle the network resources. Various architectures have been proposed so far and main key challenge for the design of this network is their vulnerability to security attacks. Therefore an efficient key management is required to overcome from such security exploitation such as unauthorised access to the network. WMNs need to be clustered into multiple groups to achieve fast and efficient security mechanism to overcome from security attacks. Therefore, we have proposed a group key agreement protocol based on Diffie-Hellman protocol and digital signature to authenticate the mesh entities within the group. The authentication took place between trusted authority (TA) and mesh clients with efficient communication and computational cost and results in reduction of packet loss by an attacker in wireless network which improves the overall performance of the WMNs. Our experimental result proves that it achieves better communication and computational cost with non-repudiation attack.

Wireless mesh networks (WMNs) have emerged as a scalable, reliable, and agile wireless network that supports many types of innovative technologies such as the Internet of Things (IoT), Wireless Sensor Networks (WSN), and Internet of Vehicles (IoV). Due to the limited number of orthogonal channels, interference between channels adversely affects the fair distribution of bandwidth among mesh clients, causing node starvation in terms of insufficient bandwidth distribution, which impedes the adoption of WMN as an efficient access technology. Therefore, a fair channel assignment is crucial for the mesh clients to utilize the available resources. However, the node starvation problem due to unfair channel distribution has been vastly overlooked during channel assignment by the extant research. Instead, existing channel assignment algorithms equally distribute the interference reduction on the links to achieve fairness which neither guarantees a fair distribution of the network bandwidth nor eliminates node starvation. In addition, the metaheuristic-based solutions such as genetic algorithm, which is commonly used for WMN, use randomness in creating initial population and selecting the new generation usually leading the search to local minima. To this end, this study proposes a Fairness-Oriented Semichaotic Genetic Algorithm-Based Channel Assignment Technique (FA-SCGA-CAA) to solve node starvation problem in wireless mesh networks. FA-SCGA-CAA maximizes link fairness while minimizing link interference using a genetic algorithm (GA) with a novel nonlinear fairness-oriented fitness function. The primary chromosome with powerful genes is created based on multicriterion links ranking channel assignment algorithm. Such a chromosome was used with a proposed semichaotic technique to create a strong population that directs the search towards the global minima effectively and efficiently. The proposed semichaotic technique was also used during the mutation and parent selection of the new genes. Extensive experiments were conducted to evaluate the proposed algorithm. A comparison with related work shows that the proposed FA-SCGA-CAA reduced the potential node starvation by 22% and improved network capacity utilization by 23%. It can be concluded that the proposed FA-SCGA-CAA is reliable to maintain high node-level fairness while maximizing the utilization of the network resources, which is the ultimate goal of many wireless networks.

With the increasing popularity of hand held devices for accessing internet services wireless mesh network has become an attractive option to internet service providers. The objective of the network is to provide seamless internet connectivity to the mobile internet users. To fulfill the objective, mobility management of the mesh clients (MC) is necessary. This paper focuses on three mobility management schemes: MEsh networks with MObility management (MEMO), Mesh Mobility Management (M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ) and adaptive mobility management scheme. The performance of the three schemes is compared quantitatively in terms of communication cost. It can be observed that the adaptive mobility management scheme performs better than the other two schemes since the adaptive scheme enables MCs to send location update message to the gateway depending on their characteristics such as: session activity and mobility.

A wireless mesh network (WMN) comprises of mesh access points (MAPs), mesh routers and mesh clients (MCs), where MAPs are almost static and form the back-bone of WMNs. MCs are wireless devices and dynamic in nature, communicating among themselves over possibly multi-hop paths, with or without the help of MAPs. Security has been a primary concern in order to provide protected communication in WMNs due to the open peer-to-peer network topology, shared wireless medium, stringent resource constraints and highly dynamic environment. These challenges clearly make a case for building multi-layer security solution that achieves both broad protection and desirable network performance. In this paper, we propose a cross-layer secure protocol for routing, data exchange and ARP problems (in case of LAN based upon WMNs). Our protocol is a ticket-based ad hoc on demand distance vector (TAODV) protocol, a secure routing protocol that is based on the design of ad hoc on demand distance vector (AODV) protocol. Due to availability of the backbone, we incorporate the authentication server (AS) for the issuance of tickets which are further used for secure routing, transfer of public keys and MAC addresses in one single step. With the transfer of public keys, source and destination can easily generate their shared secret key based upon fixed Diffie-Hellman key exchange protocol for data encryption and decryption. Our protocol is secure against both active and passive attacks.

For its self-organizing, self-configuring, and self-healing capabilities, as well as their low cost and ease of maintenance, Wireless Mesh Networks (WMNs) have emerged as a potential technology for a wide range of applications.&nbsp; Due to their inherent characteristics such as shared wireless medium, multi-hop and inter-network communication, highly dynamic network topology, and decentralised architecture, securing WMNs is a&nbsp; more challenging and complex issue.&nbsp; The WMNs are vulnerable to a variety of MAC layer attacks because of these vulnerabilities. Existing MAC layer standards and implementations are insufficient to secure these functionalities, and they do not provide comprehensive security solutions to protect both the backbone and the client mesh. As a result, efficient, scalable, and integrated security solutions for WMNs are required. We classify MAC layer attacks and examine existing countermeasures in this paper. Based on the classification of attacks and the analysis of countermeasures, we derive research directions for improving the MAC layer security of WMNs.

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.

Wireless Mesh Networks (WMNs) are gaining a lot of attention from researchers due to their advantages such as easy maintenance, low upfront cost and high robustness. Connectivity and stability directly affect the performance of WMNs. However, WMNs have some problems such as node placement problem, hidden terminal problem and so on. In our previous work, we implemented a simulation system to solve the node placement problem in WMNs considering Particle Swarm Optimization (PSO) and Distributed Genetic Algorithm (DGA), called WMN-PSODGA. In this paper, we compare chi-square and uniform distributions of mesh clients for different router replacement methods. The router replacement methods considered are Constriction Method (CM), Random Inertia Weight Method (RIWM), Linearly Decreasing Inertia Weight Method (LDIWM), Linearly Decreasing Vmax Method (LDVM) and Rational Decrement of Vmax Method (RDVM). The simulation results show that for chi-square distribution the mesh routers cover all mesh clients for all router replacement methods. In terms of load balancing, the method that achieves the best performance is RDVM. When using the uniform distribution, the mesh routers do not cover all mesh clients, but this distribution shows good load balancing for four router replacement methods, with RIWM showing the best performance. The only method that shows poor performance for this distribution is LDIWM. However, since not all mesh clients are covered when using uniform distribution, the best scenario is chi-square distribution of mesh clients with RDVM as a router replacement method.

Over the past few years, wireless mesh networks (WMNs) have emerged to become a ubiquitous solution for providing wireless access at lower cost, greater flexibility, higher reliability and performance compared to conventional wireless local area network (WLANs). As the demand for delay sensitive real-time applications such as VOIP and streaming media grows, mobility management is becoming a critical function of WMN. Although Mobility management schemes designed for Mobile Ad Hoc Networks (MANETs) and traditional fixed networks might be useful for WMNs, mobility management in WMNs is still an active research issue because of the special properties of WMNs. This chapter focuses on the mobility management in wireless mesh networks, which takes into account the unreliability of wireless mesh links and other special properties of WMNs. The chapter began by discussing the special properties of WMNs and the general concepts of mobility management, and then gives an overview of the mobility management problems in wireless mesh networks (layer 2 handoff, vertical handoff and cross layer design, etc.) with some potential solutions.

Providing security and privacy to users are critical in wireless mesh networks (WMNs). In this paper, a distributed security architecture is introduced to manage the mesh clients and a secure routing scheme that preserves the privacy of the end-users is proposed. In order to maximize routing efficiency, key indexing is used and symmetric cipher is employed in most part of the proposed scheme to reduce computational complexity. Both single-hop mesh client to mesh router and multi-hop mesh client to mesh client secure anonymous routing are proposed and discussed. Security and anonymity analysis are conducted followed by a complete performance analysis of the proposed protocol focusing on the route establish time and the routing overhead. The results show a reasonable overhead that linearly increases with the number of intermediate nodes. It is also demonstrated that the proposed schemes perform well against a broad range of attacks.

The popularity and the constant improvement of wireless technologies, such as WiFi and WiMAX, have been increasing the usage and applicability of new networking schemes, including Wireless Mesh Networks (WMNs). WMNs are multi-hop wireless networks made by a collection of two types of nodes, mesh routers and mesh clients. Their self-organizing, self-configuring and self-healing proprieties, in conjunction with their low maintenance and implementation costs, make them especially appealing as a solution for Internet access and social networking. The characteristics of WMNs make them more susceptible to malicious attacks than traditional wired networks, namely the scarce bandwidth, the high level of interference, the shared transmission media and the limited physical security. Secure routing and forwarding schemes are a key component to guarantee secure communications in hostile environments. There are however issues that must be considered when developing secure routing and forwarding solutions, namely the overhead introduced by such approaches and the effectiveness of the prediction schemes used. This paper discusses the main solutions for routing security in WMNs and presents a thorough evaluation, comprising a novel way to characterize the effectiveness of such approaches. The evaluation is based on CONFIDANT, a secure routing protocol based on the DSR protocol. The study performed addresses both the issues aforementioned and provides insight on the trade-offs associated with the deployment of secure routing and forwarding mechanisms.

The nature of wireless transmission leads to vulnerabilities to many malicious activities, and communication in wireless mesh networks (WMNs) must be protected by proper security measures. This paper focuses on symmetric pair wise key establishment and presents a new matrix-based pair wise key establishment scheme for mesh clients. In WMNs, mesh routers are much more powerful than mesh clients, both in communication and computation. By taking advantage of this heterogeneity, our new scheme delegates energy-consuming operations to mesh routers when establishing pair wise keys for mesh clients. Additionally, neighbor mesh clients in our scheme can directly establish pair wise keys with significantly reduced communication and storage costs, due to the use of both pre and post deployment knowledge.

ITS hybrid Wireless Mesh Network (WMN) is special case of WMN containing relatively static mesh points and mobile mesh clients, which may suffer from random variations in channel and network condition and handoff problems due to mobility of mesh clients. This leads to poor performance in multi-hop WMN, especially with conventional non-flexible routing algorithms. To cope with instability of wireless links and fast handoff between mesh points for mobile mesh clients, a cross-layer routing that supports link quality optimization and stable routing is an effective way. The key technology is focusing on the choice of the route metrics. In this paper we propose a novel Link Quality and Stability-aware metric from MAC layer supporting Cross-layer Routing (LQSCR) for hybrid WMN. LQSCR selects the path which has best link quality and highest neighbor stability ratio to forward data. Analysis and simulation results show that LQSCR may achieves better performance in hybrid WMN in terms of end-to-end delay, jitter delay and packet delivery ratio in comparison to shortest path metric.

Cognitive Radio (CR) technology constitutes a promising approach to increase the capacity of Wireless Mesh Networks (WMNs). Using this technology, Mesh Routers (MRs) and the attached Mesh Clients (MCs) are allowed to opportunis- tically transmit on the licensed band, but under the constraint not to interfere with the Primary Users (PUs) of the spectrum. Thus, the effective deployment of CR- WMNs require that each MR must be able to: sense the current spectrum, select an available PU-free channel and perform the spectrum handoff to a new channel in case of PU arrival on the current one. How to coordinate these actions in the optimal way which maximizes the performance of the CR-WMNs while minimizing the interference to the PUs constitutes an open research issue in CR systems. In this paper, we propose an adaptive spectrum scheduling and allocation scheme which allows a MR to identify the best schedule of (i) when to sense the current channel, (ii) when to transmit, (iii) when to perform a spectrum handoff. Due the large number of parameters involved, we propose Reinforcement Learning (RL) techniques to allow a MR to learn by itself the optimal balance between spectrum sensing-exploitation- exploration actions based on network feedbacks coming from the MCs. We perform extensive simulations which confirm the adaptivity and efficiency of our approach in terms of increased throughput when compared with non-learning based schemes for CR-WMNs.