<p>The Master’s thesis report describes the wireless mesh networks functions,</p><p>characteristics, network management and finally different protocols with security issues and applications. Wireless Networks (WMNs) are replacing wireless Infrastructure networks in many areas because of their lower and higher flexibility. The wireless mesh networks (WMNs) provides network access for both mesh and conventional clients through mesh routers and mesh clients. Communication across the network is formed via the bridge functions. Mesh router also provides the minimal mobility and form the backbone of WMNs.</p><p>Wireless mesh network has resolved the limitation of ad hoc networks which is ultimately improves the performance of Ad hoc networks. Security is a very important issue which can be resolve through proper management of network. The improvment of 802.11i security has greatly improved the network perfomance and increase the encryption and integrity security capabilities. The key points which are being addressed in this report are security issues and threats and their counter measures. Attacks which can come on diffent layers are being discussed in this survey. Security of wireless mesh network is still under consideration. Wireless mesh network are attracting more attention due to its enhanced features.</p><p>Wireless mesh network topology technology is being discussed in this report. Then network management of WMNs is explained and in the concluding chapters security issues are discussed. Threats, attacks and challenges of WMNs are discussed in this survey.</p>

The Master’s thesis report describes the wireless mesh networks functions, characteristics, network management and finally different protocols with security issues and applications. Wireless Networks (WMNs) are replacing wireless Infrastructure networks in many areas because of their lower and higher flexibility. The wireless mesh networks (WMNs) provides network access for both mesh and conventional clients through mesh routers and mesh clients. Communication across the network is formed via the bridge functions. Mesh router also provides the minimal mobility and form the backbone of WMNs. Wireless mesh network has resolved the limitation of ad hoc networks which is ultimately improves the performance of Ad hoc networks. Security is a very important issue which can be resolve through proper management of network. The improvment of 802.11i security has greatly improved the network perfomance and increase the encryption and integrity security capabilities. The key points which are being addressed in this report are security issues and threats and their counter measures. Attacks which can come on diffent layers are being discussed in this survey. Security of wireless mesh network is still under consideration. Wireless mesh network are attracting more attention due to its enhanced features. Wireless mesh network topology technology is being discussed in this report. Then network management of WMNs is explained and in the concluding chapters security issues are discussed. Threats, attacks and challenges of WMNs are discussed in this survey.

The use of wireless radio technology is well established for narrowband access systems, but its use for broadband access is relatively new. Wireless mesh architecture is a first step towards providing high-bandwidth wireless network coverage, spectral efficiency, and economic advantage. However, the widespread adoption and use of Wireless Mesh Networks (WMN) as a backbone for large wireless access networks and for last-mile subscriber access is heavily dependent on the technology’s ease of deployment. In order for WMNs to be regarded as mainstream technology, it needs to gain a competitive edge compared to wireline technologies such as DSL and cable. To achieve this, a broadband wireless network must be self-configuring, self-healing and self-organizing. In this thesis, we address these challenges. First, we propose a four-stage scheme (power-up, bootstrapping, network registration, and network optimization). We develop algorithms for each of these stages, taking advantage of the inherent properties of WMNs to determine the network’s topology. The novel part of our scheme is in the de-coupling of the subscriber’s credentials from the network hardware. This is a key part of our architecture as it helps ensure quick network enrolment, management and portability. It also helps, in our opinion, make the concept of widespread deployment using commodity hardware feasible.

The use of wireless radio technology is well established for narrowband access systems, but its use for broadband access is relatively new. Wireless mesh architecture is a first step towards providing high-bandwidth wireless network coverage, spectral efficiency, and economic advantage. However, the widespread adoption and use of Wireless Mesh Networks (WMN) as a backbone for large wireless access networks and for last-mile subscriber access is heavily dependent on the technology’s ease of deployment. In order for WMNs to be regarded as mainstream technology, it needs to gain a competitive edge compared to wireline technologies such as DSL and cable. To achieve this, a broadband wireless network must be self-configuring, self-healing and self-organizing. In this thesis, we address these challenges. First, we propose a four-stage scheme (power-up, bootstrapping, network registration, and network optimization). We develop algorithms for each of these stages, taking advantage of the inherent properties of WMNs to determine the network’s topology. The novel part of our scheme is in the de-coupling of the subscriber’s credentials from the network hardware. This is a key part of our architecture as it helps ensure quick network enrolment, management and portability. It also helps, in our opinion, make the concept of widespread deployment using commodity hardware feasible.

A thesis submitted to the Faculty of Science and Agriculture in fulfilment of the Degree of Doctor of Philosophy in the Department of Computer Science at the University of Zululand, 2017 / InfrastructureWireless Mesh Networks (I-WMNs) are increasingly used to provide network connectivity and Internet access to previously under-served areas in the developing world. It is common for some of these deployments to be battery-powered due to a lack of electrical infrastructure in the targeted areas. Thus, the energy-efficiency of these networks gains additional importance. Topology Control (TC) has been previously reported to improve the energy-efficiency and network performance of wireless ad-hoc networks, including I-WMNs. However,simulation-based studies have been relied upon to reach these conclusions and the study of TC prototypes applicable to I-WMNs has largely been limited to design issues. Thus, the study of the efficacy of TC prototypes as a mechanism for improving energy-fficiency and network performance remains an open issue. The thesis addresses this knowledge gap by studying the dynamic, run-time behaviours and the network topologies created by two standards-compatible TC prototypes. This study provides unique insight into how the prototypes consume computational resources, maintain network connectivity, produce cumulative transceiver power savings and affect the workings of the routing protocol being employed. This study also documents the topology instability caused by transceiver power oscillations produced by the PlainTC prototype. A context-based solution to reduce transceiver power oscillations and the subsequent topology instability is proposed. This solution applies the Principal Component Analysis statistical method to historical network data in order to derive the weights associated with each of the identified context variables. A threshold value is defined that only permits a node to adjust its transceiver power output if the observed change in a node’s context exceeds the threshold. The threshold mechanism is incorporated into the PlainTC+ prototype and is shown to reduce topology instability whilst improving network performance when compared to PlainTC.The results obtained in this study suggest that I-WMN topologies formed by TC are able to closely match the performance of networks that do not employ TC. However, this study shows that TC negatively affects the energy efficiency of the network despite achieving cumulative transceiver power savings.

No / Due to the attractive characteristics of high capacity, high-speed, wide coverage and low transmission power, Wireless Mesh Networks become the ideal choice for the next-generation wireless communication systems. However, the network congestion of WMNs deteriorates the quality of service provided to end users. Game theory optimization model is a novel modeling tool for the study of multiple entities and the interaction between them. On the other hand, cross-layer design is shown to be practical for optimizing the performance of network communications. Therefore, a combination of the game theory and cross-layer optimization, named cross-layer game optimization, is proposed to reduce network congestion in WMNs. In this paper, the network congestion control in the transport layer and multi-path flow assignment in the network layer of WMNs are investigated. The proposed cross-layer game optimization algorithm is then employed to enable source nodes to change their set of paths and adjust their congestion window according to the round-trip time to achieve a Nash equilibrium. Finally, evaluation results show that the proposed cross-layer game optimization scheme achieves high throughput with low transmission delay.

No description available.

Les réseaux sans fil 802.11 sont en train d'être considérés comme étant la pierre angulaire des systèmes de communication autonomes. En permettant aux usagers de communiquer les uns avec les autres avec les stations de base fixées a des endroits bien précis par l'intermédiaire de protocoles de communication comme les protocole de routage ad hoc. Le standard IEEE 802.11 propose des spéciations pour les deux couches basses (MAC et Physique) du modelé OSI. La couche MAC (Medium Access Control) introduit deux mécanismes d'accès au médium sans fil qui sont différents l'un de l'autre. Le mécanisme DCF (accès au canal distribue ou Distributed Coordination Function), l'accès au canal s'exécute dans chaque station sans faire appel à une unité centrale. Le mécanisme PCF (Point Coordination Function), contrairement au mécanisme DCF l'accès au canal se fait à l'aide d'une unité centrale. Le mécanisme le plus utilise par la norme 802.11 est DCF vu qu'il ne nécessite pas d'infrastructure au déploiement. Pour améliorer la qualité de service dans les réseaux sans multi- sauts, cette thèse aborde cette problématique dans deux couches de la pile protocolaire, à savoir la couche routage et la couches MAC. Elle améliore le routage a QoS en utilisant le protocole de routage a état de lien optimisé (OLSR) et améliore aussi l'efficacité de l'accès au médium sans fil lors du fonctionnement de la couche MAC en mode le plus courant DCF. Pour l'amélioration de routage, nous proposons une approche basée sur le graphe de conflit pour l'estimation de la bande passante partagée entre les nœuds adjacents. Pour la couche MAC, nous proposons un nouveau schéma de Backoff nomme l'algorithme Backoff de Padovane (PBA), pour améliorer l'efficacité de l'accès au médium sans fil dans les réseaux sans fil mobiles Ad Hoc (MANETs). / IEEE 802.11 based wireless networks are considered the cornerstone of autonomous communication systems. These networks allow users to communicate with each others via base stations deployed in specic locations through a set of dedicated communication protocols like Ad Hoc routing protocols. The IEEE 802.11 standard proposes specications for both physical and MAC layers of the OSI model. MAC layer denes dierent types of access to the wireless medium as explained below. The DCF (Distributed Coordination Function) mechanism, in which the access to the medium is executed localy in each station. The PCF (Point Coordination Function) method, unlike DCF mechanism the access the medium is managed by a central unit. The most widespread mechanism among them is the DCF mode as it does not require any infrastructure deployment. To improve the Quality of Service (QoS) oered to the dierent applications in multihop wireless networks, this thesis proposes original solutions to enhance the eciency of certain protocols in two dierent layers of OSI, i.e., routing and MAC layers. More specically, our proposed solutions enable higher eciency of OLSR protocol and ensure more ecient usage of the available bandwidth through the designed Padovan based medium access scheme operating in DCF mode. The routing approach used in OLSR is improved by applying the conict graphs to acquire more accurate estimation of the bandwidth shared with the adjacent nodes. At MAC layer, the number of collisions in dense networks is signicantly reduced by designing new backo scheme dubbed Padovan Backo Algorithm (BEB).

Les réseaux sans fil 802.11 sont en train d'être considérés comme étant la pierre angulaire des systèmes de communication autonomes. En permettant aux usagers de communiquer les uns avec les autres avec les stations de base fixées a des endroits bien précis par l'intermédiaire de protocoles de communication comme les protocole de routage ad hoc. Le standard IEEE 802.11 propose des spéciations pour les deux couches basses (MAC et Physique) du modelé OSI. La couche MAC (Medium Access Control) introduit deux mécanismes d'accès au médium sans fil qui sont différents l'un de l'autre. Le mécanisme DCF (accès au canal distribue ou Distributed Coordination Function), l'accès au canal s'exécute dans chaque station sans faire appel à une unité centrale. Le mécanisme PCF (Point Coordination Function), contrairement au mécanisme DCF l'accès au canal se fait à l'aide d'une unité centrale. Le mécanisme le plus utilise par la norme 802.11 est DCF vu qu'il ne nécessite pas d'infrastructure au déploiement. Pour améliorer la qualité de service dans les réseaux sans multi- sauts, cette thèse aborde cette problématique dans deux couches de la pile protocolaire, à savoir la couche routage et la couches MAC. Elle améliore le routage a QoS en utilisant le protocole de routage a état de lien optimisé (OLSR) et améliore aussi l'efficacité de l'accès au médium sans fil lors du fonctionnement de la couche MAC en mode le plus courant DCF. Pour l'amélioration de routage, nous proposons une approche basée sur le graphe de conflit pour l'estimation de la bande passante partagée entre les nœuds adjacents. Pour la couche MAC, nous proposons un nouveau schéma de Backoff nomme l'algorithme Backoff de Padovane (PBA), pour améliorer l'efficacité de l'accès au médium sans fil dans les réseaux sans fil mobiles Ad Hoc (MANETs). / IEEE 802.11 based wireless networks are considered the cornerstone of autonomous communication systems. These networks allow users to communicate with each others via base stations deployed in specic locations through a set of dedicated communication protocols like Ad Hoc routing protocols. The IEEE 802.11 standard proposes specications for both physical and MAC layers of the OSI model. MAC layer denes dierent types of access to the wireless medium as explained below. The DCF (Distributed Coordination Function) mechanism, in which the access to the medium is executed localy in each station. The PCF (Point Coordination Function) method, unlike DCF mechanism the access the medium is managed by a central unit. The most widespread mechanism among them is the DCF mode as it does not require any infrastructure deployment. To improve the Quality of Service (QoS) oered to the dierent applications in multihop wireless networks, this thesis proposes original solutions to enhance the eciency of certain protocols in two dierent layers of OSI, i.e., routing and MAC layers. More specically, our proposed solutions enable higher eciency of OLSR protocol and ensure more ecient usage of the available bandwidth through the designed Padovan based medium access scheme operating in DCF mode. The routing approach used in OLSR is improved by applying the conict graphs to acquire more accurate estimation of the bandwidth shared with the adjacent nodes. At MAC layer, the number of collisions in dense networks is signicantly reduced by designing new backo scheme dubbed Padovan Backo Algorithm (BEB).

Les réseaux sans fil 802.11 sont en train d'être considérés comme étant la pierre angulaire des systèmes de communication autonomes. En permettant aux usagers de communiquer les uns avec les autres avec les stations de base fixées a des endroits bien précis par l'intermédiaire de protocoles de communication comme les protocole de routage ad hoc. Le standard IEEE 802.11 propose des spéciations pour les deux couches basses (MAC et Physique) du modelé OSI. La couche MAC (Medium Access Control) introduit deux mécanismes d'accès au médium sans fil qui sont différents l'un de l'autre. Le mécanisme DCF (accès au canal distribue ou Distributed Coordination Function), l'accès au canal s'exécute dans chaque station sans faire appel à une unité centrale. Le mécanisme PCF (Point Coordination Function), contrairement au mécanisme DCF l'accès au canal se fait à l'aide d'une unité centrale. Le mécanisme le plus utilise par la norme 802.11 est DCF vu qu'il ne nécessite pas d'infrastructure au déploiement. Pour améliorer la qualité de service dans les réseaux sans multi- sauts, cette thèse aborde cette problématique dans deux couches de la pile protocolaire, à savoir la couche routage et la couches MAC. Elle améliore le routage a QoS en utilisant le protocole de routage a état de lien optimisé (OLSR) et améliore aussi l'efficacité de l'accès au médium sans fil lors du fonctionnement de la couche MAC en mode le plus courant DCF. Pour l'amélioration de routage, nous proposons une approche basée sur le graphe de conflit pour l'estimation de la bande passante partagée entre les nœuds adjacents. Pour la couche MAC, nous proposons un nouveau schéma de Backoff nomme l'algorithme Backoff de Padovane (PBA), pour améliorer l'efficacité de l'accès au médium sans fil dans les réseaux sans fil mobiles Ad Hoc (MANETs). / IEEE 802.11 based wireless networks are considered the cornerstone of autonomous communication systems. These networks allow users to communicate with each others via base stations deployed in specic locations through a set of dedicated communication protocols like Ad Hoc routing protocols. The IEEE 802.11 standard proposes specications for both physical and MAC layers of the OSI model. MAC layer denes dierent types of access to the wireless medium as explained below. The DCF (Distributed Coordination Function) mechanism, in which the access to the medium is executed localy in each station. The PCF (Point Coordination Function) method, unlike DCF mechanism the access the medium is managed by a central unit. The most widespread mechanism among them is the DCF mode as it does not require any infrastructure deployment. To improve the Quality of Service (QoS) oered to the dierent applications in multihop wireless networks, this thesis proposes original solutions to enhance the eciency of certain protocols in two dierent layers of OSI, i.e., routing and MAC layers. More specically, our proposed solutions enable higher eciency of OLSR protocol and ensure more ecient usage of the available bandwidth through the designed Padovan based medium access scheme operating in DCF mode. The routing approach used in OLSR is improved by applying the conict graphs to acquire more accurate estimation of the bandwidth shared with the adjacent nodes. At MAC layer, the number of collisions in dense networks is signicantly reduced by designing new backo scheme dubbed Padovan Backo Algorithm (BEB).