This thesis addresses the paucity of research on network mobility with a taxonomy and a quantitative comparison on a real test bed of existing and forthcoming network mobility solutions. Broadly, network mobility solutions can be divided into two broad categories, intra-domain and inter-domain solutions. The two are distinct enough to warrant separate solutions. Network mobility solutions can also be divided into four catogories according to their implementation, (i) Mobile IP-based solutions, (ii) Mobile IP Mobile Routing, (iii) intra-domain routing protocols, and (iv) Mobile IP Foreign Agent-based solutions. This latter division by implementation serves as a useful starting point for a discussion and study of these protocols. The qualitative and quantitive comparisons presented here yield two "winning" solutions, Mobile IP with Network Address Translation (NAT) and Mobile IP Mobile Routing, both based on Mobile IP, the draft standard for Internet mobility. The two were chosen because they are the only solutions fit for production networks, not necessarily because they are the best performing solutions. Indeed, nearly all of the other solutions are promising alternatives and some, such as mobile ad hoc network (MANET) routing protocols and the solutions based on the next generation Internet (IPv6) version of Mobile IP, are particularly so. One of the solutions uses a novel extension for Mobile IP, the Multiple Home Address extension, developed and specified in this thesis, that turns a Mobile IP mobile node into a mobile router able to support dynamically sizing mobile networks while using the existing Mobile IP infrastructure. / Master of Science

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Mobile IPv6 is a proposed mobility standard for Next Generation Wireless Access Networks that allows mobile nodes, such as laptops, tablets, smart phones to stay reachable while moving around in an IPv6 Internet network. The need for MIPv6 exists because a mobile device cannot maintain the previously connected link when changing location and IP address. The initial IP Mobility protocol was first presented in 1993 for IPv4 and in 2004 for IPv6. The Mobile IP protocol solves the TCP/IP Stack Layer 3 mobility issue, by assigning a permanent IP Home Agent address to the mobile node. IPv4 has some drawbacks, the main one being IP address exhaustion, making MIPv6 the future option for mobility protocol in IP Networks.The main goal of the mobility protocol is to enable network applications to operate continuously at the required quality of service for both wired and wireless networks while the mobile node moves around in the network. MIPv6 on its own needs optimization techniques to improve the handover latency of the protocol and to minimize the latency. This thesis investigates MIPv6 simulated using OMNeT++ Network Simulator Framework and the implementation thereof on a Linux IPv6 test bed. The test bed was used to test handover latency, overhead added by the MIPv6 extensions and packet loss. The developed test set up can also be used to evaluate different handover schemes that might enhance the MIPv6 protocol, decreasing handover latency and enabling real-time IPv6 applications such as Voice over IP. FMIPv6 and PMIPv6 are extensions to MIPv6 to enhance it's functionality. These protocols are investigated and evaluated against MIPv6 in order to make recommendations on possible improvements of these mobility protocols. / AFRIKAANSE OPSOMMING: Mobiele IPv6 is 'n voorgestelde standaard vir mobiele netwerke of die sogenaamde Volgende Generasie Netwerke wat mobiele nodes sal toelaat om bereikbaar te bly wanneer die nodes rondbeweeg in 'n IPv6 Internet omgewing. Die behoefte aan 'n kontinue netwerksessie is baie groot en dit kan toegeskryf word aan die vinnige toename in mobiele nodes, soos skootrekenaars, tablette en slimfone. Die oorspronklike IP Mobiele protokol was voorgestel in 1993 vir IPv4 en in 2004 vir IPv6. Mobiele IP dien as 'n oplossing vir netwerk mobiliteit deur te fokus op Laag 3 van die TCP/IP Stapel. Kontinue sessies word bereik deur 'n permanente Basis Adres aan die mobiele node te bind. IPv4 het heelwat nadele, waarvan die grootste een verseker IP adres uitputting is, ander nadele sluit in driehoekige roetering en invloei filtering wanneer die mobiele node rondbeweeg. Weens die genoemde nadele van MIPv4 en die stelselmatige oorgang van IPv4 na IPv6 word die fokus gerig op MIPv6 vir toekomstige verbetering en implementering. Die hoofdoel van MIPv6 is om te sorg dat mobiele nodes kan rondbeweeg in 'n network sonder om netwerk konneksie te verloor en ook om die gehalte van diens te handhaaf. MIPv6 benodig addisionele optimalisering tegnieke om die oorhandigings latensie van die protokol te verbeter en dus die gehalte van diens ook te verbeter. In die tesis ondersoek ons die elemente wat oorhandigingstydperk beinvloed en verhoog, deur MIPv6 in 'n OMNeT++ Simuleerder te evalueer. Nadat die nodige simulasie resultate verkry is, word MIPv6 geimplementeer op 'n toets netwerk om die oorhandigingstydperk te toets wanner die node rondbeweeg, oorhoofse inligting wat bygevoeg word deur MIPv6 en die aantal netwerk pakkies wat verlore gaan tydens die oorhandigingsproses. Hierna word die optimalisering tegnieke genaamd PMIPv6 en FMIPv6 ook geimplementeer op die toets netwerk om die e ektiwiteit en optimaliserings voordele teenoor die toets resultate van MIPv6 te vergelyk. Die resultate kan gebruik word om verbeterings en voorstelle te maak rakende die mobiele protokols.

User desire for ubiquitous applications on-board a vehicle motivates the necessity for Network Mobility (NEMO) solutions for Vehicular Ad-Hoc Networks (VANETs). Due to the dynamic topology of VANETs, this approach incurs excessive infrastructure cost to maintain stable connectivity and support these applications. Our solution to this problem is focused on a novel NEMO-based Network Architecture where vehicles are the main network infrastructure. Within this Architecture, we present a Network Criticality-based clustering algorithm, which adapts to mobility changes to form stable self-organizing clusters of vehicles and dynamically builds on vehicle clusters to form more stable Mobile Networks. Simulation results show that the proposed method provides more stable clusters, lower handoffs and better connectivity compared to popular density-based vehicle clustering methods. In addition, they confirm the validity of the proposed Network Architecture. The proposed method is also robust to channel error and exhibits better performance when the heterogeneity of vehicles is exploited.

User desire for ubiquitous applications on-board a vehicle motivates the necessity for Network Mobility (NEMO) solutions for Vehicular Ad-Hoc Networks (VANETs). Due to the dynamic topology of VANETs, this approach incurs excessive infrastructure cost to maintain stable connectivity and support these applications. Our solution to this problem is focused on a novel NEMO-based Network Architecture where vehicles are the main network infrastructure. Within this Architecture, we present a Network Criticality-based clustering algorithm, which adapts to mobility changes to form stable self-organizing clusters of vehicles and dynamically builds on vehicle clusters to form more stable Mobile Networks. Simulation results show that the proposed method provides more stable clusters, lower handoffs and better connectivity compared to popular density-based vehicle clustering methods. In addition, they confirm the validity of the proposed Network Architecture. The proposed method is also robust to channel error and exhibits better performance when the heterogeneity of vehicles is exploited.

Cette thèse présente une solution pour améliorer la mobilité des réseaux, dans le cadre de communications véhiculaires ainsi que pour la distribution de contenu. Les solutions actuelles pour les communications véhiculaires (c'est-à-dire lorsqu'un réseau est mobile) reposent sur la mise en place de tunnels, permettant également d'utiliser simultanément les différentes interfaces disponibles sur le véhicule (multi-homing). Même avec des tunnels, ces solutions ne sont pas en mesure d'équilibrer le trafic sur les interfaces réseau disponibles, elles ne parviennent pas à tirer partie du multi-homing. De plus, certaines des solutions existantes pour la mobilité de réseau cachent la mobilité aux hôtes connectés au routeur mobile. De fait, cela empêche les hôtes de participer aux décisions relatives au multi-homing, telles que le choix de l'interface réseau à utiliser, ce qui est pourtant utile pour réaliser du routage à moindre coût. Dans cette thèse, nous proposons de combiner un protocole de mobilité réseau (tel que NEMO) avec le protocole de TCP-multivoies (MPTCP), ce qui permet aux nœuds hôtes de participer à la mobilité et au multi-homing. Cette nouvelle combinaison améliore significativement le routage et l'encapsulation de paquets causée par les tunnels. En outre, cela augmente le débit, la tolérance de panne, le temps d'aller-retour et réduit le délai de transmission. La deuxième contribution de ce travail propose une solution de continuité de session pour la distribution de contenu dans les réseaux 5G. Dans le réseau 5G, les équipements d'accès IP seront au plus proche des nœuds terminaux afin d'améliorer l'expérience utilisateur et de réduire la charge de trafic dans le réseau central. Le fait est qu'à un instant donné un terminal ne peut être raccordé qu'à une seule passerelle (SGW/PGW) à la fois. Et comme la passerelle change lors de la mobilité, les sessions en cours seront rompues, impactant les applications temps réelle, le streaming vidéo, les jeux, etc. Pour cela, la thèse présente une solution de continuité de session avec l'aide de TCP-multivoie en bénéficiant du fait que les serveurs de contenu sont stationnaires. / This thesis presents a solution for boosting network mobility in the context of vehicular communications and content distribution in fixed network. Existing solutions for vehicular communications (i.e., network mobility), relies on tunneling in order to use multiple available interfaces on a vehicle. Even with tunnels, these solutions are unable to balance the traffic over available network interfaces thus do not reach the goal to provide optimum multi-homing benefits. Moreover, some of the existing solutions for network mobility, hide the mobility from the hosts connected to the mobile router. This in result inhibits the host nodes from participating in multi-homing related decisions such as interface selection which can be helpful in performing least cost routing. In this thesis, we propose to combine network mobility protocol with MPTCP which enables the host nodes to participate in mobility and multi-homing. This novel combination significantly improves routing and tunneling packet overhead. Moreover it increases throughput, fault tolerance, round-trip time and reduces transmission delay. The second contribution of this work is providing a solution for session continuity in context of content distribution in 5G networks. In 5G network, the IP edges will be closer to the host nodes in order to improve the user experience and reduce traffic load in the core network. The fact that a host can only be connected to a single gateway (SGW/PGW) at a time, would break the ongoing sessions for real time applications like video streaming or gaming during an occurrence of mobility event requiring gateway relocation. The thesis presents the solution for session continuity with the help of multipath TCP by benefiting from the fact that the content servers are stationary.

Au cours des dernières décennies, le besoin pour des communications multimédia en mobilité est devenu indéniable dans les réseaux de type IP, ainsi la gestion de la mobilité et la continuité de session est depuis plusieurs années un problème de recherche très important aussi bien pour le milieu académique qu’industriel. Comme l'hétérogénéité des réseaux d’accès est en perpétuelle évolution, l'intégration des différents types de réseaux sans fil au niveau de la couche IP est devenue un domaine de recherche difficile et inévitable. L'un des problèmes les plus importants liés à l'exécution de la gestion de la mobilité concerne le fait que la couche d'application souffre de la modification d'adresses IP au cours du mouvement du nœud mobile alors que celle-ci construit sa session sur la base de l’adresse IP de connexion au réseau. Une nouvelle approche d'amélioration de la prise en charge de la mobilité propose de séparer l'identification de session et l'identification de l’emplacement ou l’attachement au réseau. Donc, par la séparation de ces deux concepts, les sessions ne sont pas identifiés par les adresses IP qui elles sont dynamiques puisque la mobilité dans le réseau impose le changement d’adresse IP, mais les nouveaux identificateurs uniques qui définissent un nœud et qui ne change pas à cause de la mobilité ce qui offrirait une stabilité pour le niveau applicatif. Selon ces concepts, Host Identity Protocol (HIP) est l'une des solutions dominantes en recherches qui est proposé par l'IETF et l’IRTF. Dans cette thèse, le protocole HIP est principalement examiné et de nouvelles améliorations de la mobilité sur la base de ce protocole ont été conçues et mises en place / Over the last decades, with rapid and tremendous growth of IP networks in mobile and wireless environments, mobility management and session continuity has become a more important issue. As the heterogeneity increases in network environments and gradual spread of Internet of Things wave, the integration of different types of wireless networks in the IP layer became a challenging and inevitable research area. One of the most important issues related to mobility management is related to the fact that the application layer suffers from the changing of IP addresses during the movement of the mobile node. It is expected the network layer and above layers to be aware of movement of mobile nodes. New wave in the improvement ideas on this concept is separating the session identification and the location identification. This avoids the applications to suffer when the IP address changes during the mobility. This new approach needs to introduce a new layer in the TCP/IP protocol stack, on top of the IP layer that will handle the new identifiers correspondent with the current IP address or new complete architecture designs which are inheriting locator/identifier separation idea. According to these concepts, Host Identity Protocol (HIP) is one of the dominant and prominent researches that is proposed by IETF and IRTF. This protocol proposes to solve the locator/identifier split problem by also including the security support. In this thesis, predominantly HIP protocol is examined and new mobility enhancements based on this protocol have been designed and introduced