Improving routing performance of multipath ad hoc on-demand distance vector in mobile add hoc networks.

The aim of this research is to improve routing fault tolerance in Mobile Ad hoc Networks (MANETs) by optimising mUltipath routing in a well-studied reactive and single path routing protocol known as Ad hoc On-demand Distance Vector (AODV). The research also aims to prove the effect of varying waiting time of Route Reply (RREP) procedure and utilising the concept of efficient routes on the performance of multipath extensions to AODV. Two novel multipath routing approaches are developed in this thesis as new extensions to AODV to optimise routing overhead by improving Route Discovery Process (RDP) and Route Maintenance Process (RMP) of multipath AODV. The first approach is a Iinkdisjoint multipath extension called 'Thresho)d efficient Routes in multipath AODV' (TRAODV) that optimises routing packets ~verhead by improving the RDP of AODV which is achieved by detecting the waiting time required for RREP procedure to receive a threshold number of efficient routes. The second approach is also a link-disjoint mUltipath extension called 'On-demand Route maintenance in Multipath AoDv' (ORMAD) which is an extension to TRAODV that optimises routing packets and delay overhead by improving the RMP of TRAODV. ORMAD applies the concepts of threshold waiting time and efficient routes to both phases RDP and RMP. It also applies RMP only to efficient routes which are selected in the RDP and when a route fails, it invokes a local repair procedure between upstream and downstream nodes of the broken link. This mechanism produces a set of alternative subroutes with less number of hops which enhances route efficiency and consequently minimises the routing overhead. TRAODV and ORMAD are implemented and evaluated against two existing multipath extensions to,AODV protocol and two traditional multipath protocols. The existing extensions to AODV used in the evaluation are a well-known protocol called Ad hoc On-demand Multipath Distance Vector (AOMDV) and a recent extension called Multiple Route AODV (MRAODV) protocol which is extended in this thesis to the new approach TRAODV while the traditional multipath protocols used in the evaluation are Dynamic Source Routing (DSR) and Temporally Ordered Routing Algorithm (TORA). Protocols are implemented using NS2 and evaluated under the same simulation environment in terms of four performance metrics; packet delivery fraction, average end-to-end delay, routing packets overhead, and throughput. Simulation results of TRAODV evaluation show that the average number of routes stored in a routing table of MRAODV protocol is always larger than the average number of routes in TRAODV. Simulation results show that TRAODV reduces the overall routing packets overhead compared to both extensions AOMDV and MRAODV, especially for large network size and high mobility. A vital drawback of TRAODV is that its performance is reduced compared to AOMDV and MRAODV in terms of average end-to-end delay. Additionally, TORA still outperforms TRAODV and the other extensions to AODV in terms of routing packets overhead. In order to overcome the drawbacks of TRAODV, ORMAD is developed by improving the RDP of TRAODV. The performance of ORMAD is evaluated against RREP waiting time using the idea of utilising the efficient routes in both phases RDP and RMP. Simulation results of ORMAD show that the performance is affected by varying the two RREP waiting times of both RDP and RMP in different scenarios. As shown by the simulation results, applying the short and long waiting times in both phases tends to less performance in terms of routing packets overhead while applying the moderate waiting times tends to better performance. ORMAD enhances routing packets overhead and the average end-to-end delay compared to TRAODV, especially in high mobility scenarios. ORMAD has the closest performance to TORA protocol in terms of routing packets overhead compared to ~M~a~M~OW . Relevant concepts are formalised for ORMAD approach and conducted as an analytical model in this thesis involving the\vhole process of multipath routing in AODV extensions. ORMAD analytical model describes how the two phases RDP and RMP interact with each other with regard to two performance metrics; total number of detected routes and Route Efficiency.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Models and Protocols for Resource Optimization in Wireless Mesh Networks

Wireless mesh networks are built on a mix of fixed and mobile nodes interconnected via wireless links to form a multihop ad hoc network. An emerging application area for wireless mesh networks is their evolution into a converged infrastructure used to share and extend, to mobile users, the wireless Internet connectivity of sparsely deployed fixed lines with heterogeneous capacity, ranging from ISP-owned broadband links to subscriber owned low-speed connections. In this thesis we address different key research issues for this networking scenario. First, we propose an analytical predictive tool, developing a queuing network model capable of predicting the network capacity and we use it in a load aware routing protocol in order to provide, to the end users, a quality of service based on the throughput. We then extend the queuing network model and introduce a multi-class queuing network model to predict analytically the average end-to-end packet delay of the traffic flows among the mobile end users and the Internet. The analytical models are validated against simulation. Second, we propose an address auto-configuration solution to extend the coverage of a wireless mesh network by interconnecting it to a mobile ad hoc network in a transparent way for the infrastructure network (i.e., the legacy Internet interconnected to the wireless mesh network). Third, we implement two real testbed prototypes of the proposed solutions as a proof-of-concept, both for the load aware routing protocol and the auto-configuration protocol. Finally we discuss the issues related to the adoption of ad hoc networking technologies to address the fragility of our communication infrastructure and to build the next generation of dependable, secure and rapidly deployable communications infrastructures

Method and System for Name Resolution Across Heterogeneous Architectures

One embodiment of the present invention provides a system for resolving a name request in a network comprising a plurality of groups that use different name-resolution schemes. During operation, the system receives, at a first group, the name request; identifies a parent group of the first group, which is a member of the parent group; and in response to failing to resolve the name request within the first group, forwards the name request to the identified parent group

Advanced Metering Infrastructure Based on Smart Meters in Smart Grid

Due to lack of situational awareness, automated analysis, poor visibility, and mechanical switches, today\u27s electric power grid has been aging and ill‐suited to the demand for electricity, which has gradually increased, in the twenty‐first century. Besides, the global climate change and the greenhouse gas emissions on the Earth caused by the electricity industries, the growing population, one‐way communication, equipment failures, energy storage problems, the capacity limitations of electricity generation, decrease in fossil fuels, and resilience problems put more stress on the existing power grid. Consequently, the smart grid (SG) has emerged to address these challenges. To realize the SG, an advanced metering infrastructure (AMI) based on smart meters is the most important key

Routage et gestion de la mobilité dans les réseaux personnels

L'objectif de cette thèse est d'étudier des méthodes et des stratégies efficaces pour le routage et la gestion de la mobilité dans le cadre des réseaux personnels. Dans un premier temps, nous proposons le cadre de nos études: Personal Ubiquitous Environments (PUE). Un PUE est constitué d'un ensemble d'utilisateurs ayant des terminaux disposant d'interfaces réseau hétérogènes, et dont l'objectif est de mettre en oeuvre des mécanismes de coopération et de partage des ressources de manière totalement distribuée. Dans ce cadre, la thèse a proposé des solutions innovantes contribuant à améliorer la communication inter et intra réseau personnels. La première contribution porte sur le protocole PNRP (Personal Network Routing Protocol) dont le but est de développer un routage à base de politiques (policy-based routing) pour les environnements personnels. La seconde, intitulée ADD (Adaptive Distributed gateway Discovery), est un mécanisme totalement distribué pour la découverte de multiples chemins vers une passerelle vers un réseau opéré. De plus, étant donné que ces environnements sont hétérogènes par leurs compositions (réseaux d'accès, terminaux ...), une architecture de gestion de la mobilité qui permet une gestion unifiée de la localisation et de la mobilité sans coutures appliquant lénsemble des noeuds a également été traitée. Les résultats d'évaluation par simulation démontrent l'applicabilité et léfficacité des ces protocoles.The aim of this thesis is to investigate methods and strategies for efficient routing and mobility management in personal environments. The concept of Personal Ubiquitous Environments (PUE) is introduced which accommodates heterogeneous devices and access networks of different users and sustain the notion of sharing resources in a distributed manner. A prerequisite for achieving the resource (devices, networks) sharing in personal environments is the deployment of suitable communication protocols which establish efficient multi-hop routes betweens the devices of the PUE. Personal Network Routing Protocol (PNRP) has been developed to perform policy-based routing in personal environments. Moreover, in certain personal networking scenarios, the infrastructure network components (i.e. gateways) are more than one-hop distance from the user's devices; Adaptive Distributed gateway Discovery (ADD) protocol is thereby proposed to efficiently discover the multi-hop routes towards the gateway in a totally distributed manner. All the more, since the personal environments regroups heterogeneous access networks, an efficient mobility management architecture is proposed which offers unified location management and seamless handover experience to dynamic personal nodes. The proposed protocols are assessed by means of numerous communication scenarios; the simulation results demonstrate the applicability of the proposed protocols

Techniques to enhance the lifetime of mobile ad hoc networks

Devices in Mobile Ad Hoc Networks (MANETs) are mostly powered by battery. Since the battery capacity is fixed, some techniques to save energy at the device level or at the protocol stack should be applied to enhance the MANETs lifetime. In this thesis, we have proposed a few energy saving approaches at the network layer, and MAC layer. First, we proposed a routing technique, to which the following metrics are built into: (i) node lifetime, (ii) maximum limit on the number of connections to a destination, and (iii) variable transmission power. In this technique, we consider a new cost metric which takes into account the residual battery power and energy consumption rate in computing the lifetime of a node. To minimize the overutilization of a node, an upper bound is set on the number of connections that can be established to a destination. The proposed technique is compared with AODV [1] and LER [2]. It outperforms AODV and LER in terms of network lifetime. Next, a technique called Location Based Topology Control with Sleep Scheduling (LBTC) is proposed. It uses the feature of both topology control approach in which the transmission power of a node is reduced, and power management approach in which nodes are put to sleep state. In LBTC the transmission power of a node is determined from the neighborhood location information. A node goes to sleep state only when: (i) it has no traffic to participate, and (ii) its absence does not create a local partition. LBTC is compared with LFTC [3] and ANTC [4]. We observed that the network lifetime in LBTC is substantially enhanced. A framework for post-disaster communication using wireless ad hoc networks is proposed. This framework includes: (i) a multi-channel MAC protocol, (ii) a node-disjoint multipath routing, and (iii) a distributed topology aware scheme. Multi-channel MAC protocol minimizes the congestion in the network by transmitting data through multiple channels. Multipath routing overcomes the higher energy depletion rate at nodes associated with shortest path routing. Topology aware scheme minimizes the maximum power used at node level. Above proposals, taken together intend to increase the network throughput, reduce the end-to-end delay, and enhance the network lifetime of an ad hoc network deployed for disaster response

Sécurité collaborative pour l internet des objets

Cette thèse aborde des nouveaux défis de sécurité dans l'Internet des Objets (IdO). La transition actuelle de l'Internet classique vers l'Internet des Objets conduit à de nombreux changements dans les modèles de communications sous-jacents. La nature hétérogène des communications de l IdO et le déséquilibre entre les capacités des entités communicantes qui le constituent rendent difficile l'établissement de connexions sécurisées de bout en bout. Contrairement aux nœuds de l Internet traditionnel, la plupart des composants de l'Internet des Objets sont en effet caractérisés par de faibles capacités en termes d'énergie et de puissance calcul. Par conséquent, ils ne sont pas en mesure de supporter des systèmes de sécurité complexes. En particulier, la mise en place d'un canal de communication sécurisé de bout en bout nécessite l établissement d'une clé secrète commune entre les deux nœuds souhaitant communiquer, qui sera négociée en s'appuyant sur un protocole d'échange de clés tels que le Transport Layer Security (TLS) Handshake ou l Internet Key Exchange (IKE). Or, une utilisation directe de ces protocoles pour établir des connexions sécurisées entre deux entités de l IdO peut être difficile en raison de l'écart technologique entre celles-ci et des incohérences qui en résultent sur le plan des primitives cryptographiques supportées. Le sujet de l'adaptation des protocoles de sécurité existants pour répondre à ces nouveaux défis a récemment été soulevé dans la communauté scientifique. Cependant, les premières solutions proposées n'ont pas réussi à répondre aux besoins des nœuds à ressources limitées. Dans cette thèse, nous proposons de nouvelles approches collaboratives pour l'établissement de clés, dans le but de réduire les exigences des protocoles de sécurité existants, afin que ceux-ci puissent être mis en œuvre par des nœuds à ressources limitées. Nous avons particulièrement retenu les protocoles TLS Handshake, IKE et HIP BEX comme les meilleurs candidats correspondant aux exigences de sécurité de bout en bout pour l'IdO. Puis nous les avons modifiés de sorte que le nœud contraint en énergie puisse déléguer les opérations cryptographiques couteuses à un ensemble de nœuds au voisinage, tirant ainsi avantage de l'hétérogénéité spatiale qui caractérise l IdO. Nous avons entrepris des vérifications formelles de sécurité et des analyses de performance qui prouvent la sureté et l'efficacité énergétique des protocoles collaboratifs proposés. Dans une deuxième partie, nous avons porté notre attention sur une classe d attaques internes que la collaboration entre les nœuds peut induire et que les mécanismes cryptographiques classiques, tels que la signature et le chiffrement, s'avèrent impuissants à contrer. Cela nous a amené à introduire la notion de confiance au sein d'un groupe collaboratif. Le niveau de fiabilité d'un nœud est évalué par un mécanisme de sécurité dédié, connu sous le nom de système de gestion de confiance. Ce système est lui aussi instancié sur une base collaborative, dans laquelle plusieurs nœuds partagent leurs témoignages respectifs au sujet de la fiabilité des autres nœuds. En nous appuyant sur une analyse approfondie des systèmes de gestion de confiance existants et des contraintes de l IoD, nous avons conçu un système de gestion de confiance efficace pour nos protocoles collaboratifs. Cette efficacité a été évaluée en tenant compte de la façon dont le système de gestion de la confiance répond aux exigences spécifiques à nos approches proposées pour l'établissement de clés dans le contexte de l'IdO. Les résultats des analyses de performance que nous avons menées démontrent le bon fonctionnement du système proposé et une efficacité accrue par rapport à la littératureThis thesis addresses new security challenges in the Internet of Things (IoT). The current transition from legacy Internet to Internet of Things leads to multiple changes in its communication paradigms. Wireless sensor networks (WSNs) initiated this transition by introducing unattended wireless topologies, mostly made of resource constrained nodes, in which radio spectrum therefore ceased to be the only resource worthy of optimization. Today's Machine to Machine (M2M) and Internet of Things architectures further accentuated this trend, not only by involving wider architectures but also by adding heterogeneity, resource capabilities inconstancy and autonomy to once uniform and deterministic systems. The heterogeneous nature of IoT communications and imbalance in resources capabilities between IoT entities make it challenging to provide the required end-to-end secured connections. Unlike Internet servers, most of IoT components are characterized by low capabilities in terms of both energy and computing resources, and thus, are unable to support complex security schemes. The setup of a secure end-to-end communication channel requires the establishment of a common secret key between both peers, which would be negotiated relying on standard security key exchange protocols such as Transport Layer Security (TLS) Handshake or Internet Key Exchange (IKE). Nevertheless, a direct use of existing key establishment protocols to initiate connections between two IoT entities may be impractical because of the technological gap between them and the resulting inconsistencies in their cryptographic primitives. The issue of adapting existing security protocols to fulfil these new challenges has recently been raised in the international research community but the first proposed solutions failed to satisfy the needs of resource-constrained nodes. In this thesis, we propose novel collaborative approaches for key establishment designed to reduce the requirements of existing security protocols, in order to be supported by resource-constrained devices. We particularly retained TLS handshake, Internet key Exchange and HIP BEX protocols as the best keying candidates fitting the end-to-end security requirements of the IoT. Then we redesigned them so that the constrained peer may delegate its heavy cryptographic load to less constrained nodes in neighbourhood exploiting the spatial heterogeneity of IoT nodes. Formal security verifications and performance analyses were also conducted to ensure the security effectiveness and energy efficiency of our collaborative protocols. However, allowing collaboration between nodes may open the way to a new class of threats, known as internal attacks that conventional cryptographic mechanisms fail to deal with. This introduces the concept of trustworthiness within a collaborative group. The trustworthiness level of a node has to be assessed by a dedicated security mechanism known as a trust management system. This system aims to track nodes behaviours to detect untrustworthy elements and select reliable ones for collaborative services assistance. In turn, a trust management system is instantiated on a collaborative basis, wherein multiple nodes share their evidences about one another's trustworthiness. Based on an extensive analysis of prior trust management systems, we have identified a set of best practices that provided us guidance to design an effective trust management system for our collaborative keying protocols. This effectiveness was assessed by considering how the trust management system could fulfil specific requirements of our proposed approaches for key establishment in the context of the IoT. Performance analysis results show the proper functioning and effectiveness of the proposed system as compared with its counterparts that exist in the literatureEVRY-INT (912282302) / SudocSudocFranceF

User-centred and context-aware identity management in mobile ad-hoc networks

The emergent notion of ubiquitous computing makes it possible for mobile devices to communicate and provide services via networks connected in an ad-hoc manner. These have resulted in the proliferation of wireless technologies such as Mobile Ad-hoc Networks (MANets), which offer attractive solutions for services that need flexible setup as well as dynamic and low cost wireless connectivity. However, the growing trend outlined above also raises serious concerns over Identity Management (IM) due to a dramatic increase in identity theft. The problem is even greater in service-oriented architectures, where partial identities are sprinkled across many services and users have no control over such identities. In this thesis, we review some issues of contextual computing, its implications and usage within pervasive environments. To tackle the above problems, it is essential to allow users to have control over their own identities in MANet environments. So far, the development of such identity control remains a significant challenge for the research community. The main focus of this thesis is on the area of identity management in MANets and emergency situations by using context-awareness and user-centricity together with its security issues and implications. Context- awareness allows us to make use of partial identities as a way of user identity protection and node identification. User-centricity is aimed at putting users in control of their partial identities, policies and rules for privacy protection. These principles help us to propose an innovative, easy-to-use identity management framework for MANets. The framework makes the flow of partial identities explicit; gives users control over such identities based on their respective situations and contexts, and creates a balance between convenience and privacy. The thesis presents our proposed framework, its development and lab results/evaluations, and outlines possible future work to improve the framework

Routing and interworking protocols for next generation wireless networks

EThOS - Electronic Theses Online ServiceGBUnited Kingdo