Technological advancements have led to an increase in the number of wireless and mobile devices such as PDAs, laptops and smart phones. This has resulted in an ever- increasing demand for wireless access to the Internet. Hence, wireless mobile traffic is expected to form a significant fraction of Internet traffic in the near future, over the so-called Mobile Internet Protocol (MIP) networks. For real-time applications, such as voice, video and process monitoring and control, deployed over standard IP networks, network resources must be properly allocated so that the mobile end-user is guaranteed a certain Quality of Service (QoS). As with the wired and fixed IP networks, MIP networks do not offer any QoS guarantees. Such networks have been designed for non-real-time applications. In attempts to deploy real-time applications in such networks without requiring major network infrastructure modifications, the end-points must provide some level of QoS guarantees. Such QoS guarantees or QoS control, requires ability of predictive capabilities of the end-to-end flow characteristics. In this research network flow accumulation is used as a measure of end-to-end network congestion. Careful analysis and study of the flow accumulation signal shows that it has long-term dependencies and it is very noisy, thus making it very difficult to predict. Hence, this work predicts the moving average of the flow accumulation signal. Both single-step and multi-step predictors are developed using linear system identification techniques. A multi-step prediction error of up to 17% is achieved for prediction horizon of up to 0.5sec. The main thrust of this research is on the impact of wireless losses on the ability to predict end-to-end flow accumulation. As opposed to wired, congestion related packet losses, the losses occurring in a wireless channel are to a large extent random, making the prediction of flow accumulation more challenging. Flow accumulation prediction studies in this research demonstrate that, if an accurate predictor is employed, the increase in prediction error is up to 170% when wireless loss reaches as high as 15% , as compared to the case of no wireless loss. As the predictor accuracy in the case of no wireless loss deteriorates, the impact of wireless losses on the flow accumulation prediction error decreases.

Les systèmes de transport intelligents coopératifs permettent la communication des véhicules entre eux ainsi qu'avec l'infrastructure, afin d'assurer la disponibilité des informations d'une manière plus fiable sur les véhicules, leurs positions et les conditions de la route. Cet échange d'informations pertinentes permet d'améliorer la sécurité routière, réduire les incidents du trafic et d'assurer l'efficacité de la mobilité des véhicules. IEEE 802.11p est standardisé comme la technologie par défaut pour les communications des véhicules. Dans ce contexte, le standard européen ETSI s'attaque en particulier aux applications de la sécurité routière. Pour ce faire, il standardise plusieurs types de messages comme CAM (Cooperative Awareness Message) et DENM (Decentralised Event Notification Message). Les CAMs sont des messages de diffusion à un seul-saut, envoyés par chaque véhicule contenant des informations sur sa position, sa vitesse, sa direction, etc., afin d'assurer une coopération lucide entre les autres usagers de la route (y compris les véhicules). Les DENMs sont envoyés à la détection d'un événement sur la route, comme le cas d'un accident, embouteillages, etc. Si nécessaire, une communication multi-saut, exploitant des algorithmes de routage standardisés, est mise en {oe}uvre pour disséminer ces messages au-delà de la portée du transmetteur. La faiblesse de 802.11p réside dans la congestion du canal radio due à la bande passante limitée (5.9 GHz). Afin de pallier à cela, ETSI a proposé un cadre pour le contrôle de la congestion appelé DCC (Distributed Congestion Control). Celui-ci permet l'échange d'informations, en particulier l'état du canal radio, entre les couches de la pile protocolaire. Ainsi, chaque protocole de communication contrôle ses propres paramètres pour éviter la congestion du canal. Par ailleurs beaucoup d'approches de contrôle de la congestion DCC existent pour les messages CAM tel que le contrôle de la période de génération des CAMs sur la couche Facilities. La puissance de transmission ou le débit sur la couche Accès, etc. En revanche, peu de travaux ont été faits sur DENMs. A cet égard, nous avons proposé une approche DCC sur la couche GeoNetworking qui contrôle les paramètres de routage en se basant sur l'état du canal radio. Une évaluation du dual-DCC, à savoir CAM sur Facilities et DENM sur GeoNet, a démontré l'efficacité de l'approche proposée. En outre, certaines applications tel que la gestion d'une flotte de véhicules, ont besoin d'un centre de contrôle localisé sur Internet qui communique avec la flotte. Pour ce type d'échange, une communication hybride (IP et Géo) est nécessaire. De plus pour assurer la fluidité de la communication, la gestion de la mobilité est primordiale. Tout en restant dans le cadre de l'architecture Mobile IP, nous proposons notre approche d'adressage qui constitue une adresse IP routable avec une adresse GeoNetworking, ce qui permet de traiter le problème d'accessibilité des véhicules en mouvement sur la route à partir d'une entité située sur Internet. Contrairement à Mobile IP, notre approche permet de réduire la surcharge de la signalisation. Et cela grâce au partitionnement de la route en zones de routage (RA) de telle sorte que l'accès à Internet se fait via une passerelle RSU-FA qui contrôle la RA. Chaque RA regroupe un certain nombre de RSUs. / Cooperative intelligent transport systems allow vehicles to communicate with each other as well as with the infrastructure in order to ensure the availability of information more reliably on vehicles, their positions and road conditions. This exchange of relevant information improves road safety, reduces traffic incidents and ensures efficient mobility of vehicles. IEEE 802.11p is standardized as the default technology for vehicle communications. In this context, the European ETSI standard addresses in particular road safety applications. To do this, it standardizes several types of messages such as CAM (Cooperative Awareness Message) and DENM (Decentralized Event Notification Message). CAMs are single-hop broadcast messages, sent by each vehicle containing information on its position, speed, direction, etc., in order to ensure lucid cooperation between other road users (including vehicles). The DENMs are sent when there is a detection of an event on the road, as in the case of an accident, traffic jams, etc. If necessary, multi-hop communication, using standardized routing algorithms, is implemented to disseminate these messages beyond the scope of the transmitter. The weakness of 802.11p lies in congestion of the radio channel due to the limited bandwidth (5.9 GHz). In order to compensate for this, ETSI proposed a framework for congestion control called DCC (Distributed Congestion Control). This allows the exchange of information, in particular the state of the radio channel, between the layers of the protocol stack. Thus, each communication protocol controls its own parameters to avoid congestion of the channel. In addition, many DCC congestion control approaches exist for CAM messages such as the control of the CAM generation period on the Facilities layer. Transmission power or data rate on the Access layer, etc. On the other hand, little works have been done on DENMs. In this regard, we proposed a DCC approach on the GeoNetworking layer which controls the routing parameters based on the state of the radio channel. An evaluation of the dual-DCC, namely CAM on Facilities and DENM on GeoNet, demonstrated the effectiveness of the proposed approach. In addition, some applications such as managing a fleet of vehicles require a localized control center that communicates with the fleet. For this type of exchange, a hybrid communication (IP and Geo) is necessary. Moreover, to ensure the fluidity of communication, the management of mobility is paramount. While remaining within the framework of the Mobile IP architecture, we propose our approach of addressing which constitutes a routable IP address with a geonetworking address, which makes it possible to deal with the problem of accessibility of vehicles moving on the road from of an entity on the Internet. Unlike Mobile IP, our approach reduces the overhead of signaling. This is done by partitioning the road into routing area (RA) in such a way that the access to the Internet is via a RSU-FA gateway that controls the RA. Each RA regroups a number of RSUs.

Approved for public release, distribution is unlimited / With the rapidly growing demand for portable devices such as laptops, handheld computers and Personal Digital Assistants (PDAs) with wireless networking capabilities, the need for reliable wireless data network communication has also increased. Just like in mobile voice communication, users demand uninterrupted, secure wireless data communication as they move from place to place. Mobile IP satisfies some of these demands - it enables mobile devices with fixed IP addresses to be permanently reachable even as their point of attachment to the network changes. This allows for routing of data packets to and from the mobile device irrespective of its location on the network. While uninterrupted data flow can be achieved with Mobile IP, it introduces additional security vulnerabilities, including data privacy, data integrity and authentication. The goal of this thesis is to investigate such vulnerabilities and explore implementations to overcome them. / Civilian, National Science Foundation

Dans cette thèse, nous proposons différents mécanismes de gestion de la mobilité et de support de qualité de service (QoS) dans les réseaux cellulaires tout-IP. Avant d'entamer nos travaux de recherche, nous examinons et analysons tout d'abord l'architecture des réseaux mobiles tout-IP ainsi que la complexité et les problèmes liés aux performances des protocoles de macro- et micro-mobilité existants. Les résultats de cette analyse seront ensuite exploités pour présenter et discuter nos propositions. L'objectif recherché est d'assurer, au moindre coût, le meilleur support de la mobilité et d'offrir les garanties de QoS exigées par les applications temps réel. Notre solution de base, intitulée ``Micro Mobile MPLS'', repose sur l'intégration du protocole Mobile IP hiérarchique avec le protocole de commutation de labels (MPLS). Outre le support de la QoS, notre architecture est flexible, scalable (résiste au passage à l'échelle) et supporte les modèles Diffserv et Intserv. En effet, les chemins ou LSPs (Label witched Paths) peuvent être établis soit à l'avance par provisioning (on parle dans ce cas de LSPs statiques), soit dynamiquement sur demande (on parle dans ce cas de LSPs dynamiques). Dans un second temps, nous exposons trois variantes protocolaires proposées pour compléter notre solution de base ``Micro Mobile MPLS''. La première variante, intitulée ``FH-Micro Mobile MPLS'', supporte le fast handover pour réduire les perturbations des communications en cours en minimisant le temps de handover. La deuxième variante, intitulée ``FC-Micro Mobile MPLS'', est basée sur une suite de chemins construits dynamiquement pour réduire le coût de signalisation lors des mises à jour de localisation. En effet, en utilisant ce mécanisme, le terminal mobile a la capacité de s'enregistrer auprès de son ancien sous-réseau au lieu du noeud d'entrée du domaine formant ainsi une suite de chemins de tous les sous-réseaux visités. Enfin, la troisième variante protocolaire, intitulée ``MFC-Micro Mobile MPLS'', propose de réduire la charge de signalisation au sein du réseau d'accès en contrôlant dynamiquement le nombre des mises à jour de localisation auprès du noeud d'entrée du domaine. Ceci permet d'assurer une flexibilité et une adaptabilité optimales, en tenant compte des caractéristiques du réseau et de la mobilité des utilisateurs. Tout au long de ce travail, des études de performances, basée sur des analyses théoriques et également sur des simulations ont été réalisées afin d'évaluer l'efficacité de nos propositions. Des modèles de mobilité basés sur des chaînes de Markov sont développés en adoptant des configurations cellulaires à une dimension (1-D) et à deux dimensions (2-D). Les critères de performances utilisés correspondent au coût d'utilisation des liens, au coût de signalisation lors des mises à jour de localisation ou encore coût d'enregistrement, à la latence d'un handover et au taux de perte des paquets. Les résultats de cette analyse ont montré une nette amélioration du délai de handover et du taux de perte des paquets ainsi qu'une réduction importante du coût de signalisation permettant par ailleurs de garantir une bonne qualité de service pour les applications temps réel.

Expanding the global Internet to include mobile devices is an exciting area of current research. Because of the vast size of the Internet, and because the protocols in it are already widely deployed, mobile devices must inter-operate with those protocols. Although most of the incompatiblities with mobiles have been solved, the protocols that deliver data reliably, and that account for the majority of Internet traffic, perform very poorly. A change in location causes a disruption in traffic, and disruption is dealt with by algorithms tailored only for stationary hosts. The Transmission Control Protocol (TCP) is the predominant transport-layer protocol in the Internet. In this thesis, we look at the performance of TCP in mobile environments. We provide a complete explanation for poor performance; we conduct a large number of experiments, simulations, and analyses that prove and quantify poor performance;and we propose simple and scalable solutions that address the limitations.

Expanding the global Internet to include mobile devices is an exciting area of current research. Because of the vast size of the Internet, and because the protocols in it are already widely deployed, mobile devices must inter-operate with those protocols. Although most of the incompatiblities with mobiles have been solved, the protocols that deliver data reliably, and that account for the majority of Internet traffic, perform very poorly. A change in location causes a disruption in traffic, and disruption is dealt with by algorithms tailored only for stationary hosts. The Transmission Control Protocol (TCP) is the predominant transport-layer protocol in the Internet. In this thesis, we look at the performance of TCP in mobile environments. We provide a complete explanation for poor performance; we conduct a large number of experiments, simulations, and analyses that prove and quantify poor performance;and we propose simple and scalable solutions that address the limitations.

Nowadays in mobile and wireless networks environment, Mobile IP is the preferred standard in supporting IP mobility among several standards. However, several problems still need to be solved. One of them is the triangle routing problem. Although drafts have been proposed by the IETF (Internet Engineering Task Force) for solving this problem, the proposed solution can not be achieved unless the draft of the Mobile IP route optimization method becomes a typical standard of the Mobile IP. In this paper, we present an extended routing agent architecture to solve this problem. The Middle Mobility Agent (MMA) in the proposed architecture can intercept datagrams earlier and determine to tunnel the incoming packet or not than the MH¡¦s original home agent. This architecture can solve the triangle routing problem by reducing packet¡¦s routing length. An analytical model and a simulation environment were set up to evaluate and measure the packet¡¦s routing length and delay time of proposed architecture. The evaluation and simulation results demonstrate that the proposed method can reduce the routing length, delay time and solve the triangle routing problem.

Today¡¦s mobile IP supports host mobility by dynamic changing IP addresses while the mobile host roaming in the Internet. However, There still exists performance problems during handoffs, such as packet loss, throughput degradation, and so on. In this Thesis, we propose a mechanism to reduce packet loss during handoff. The packet buffering mechanism at a home agent is initiated by mobile hosts when the signal-to-noise ratio of the wireless link falls below some predefined threshold. Once the handoff has completed, the home agent immediately delivers the first packet in the buffer to the mobile host. The home agent then clears the buffered packets already received by the mobile host through the returned ACK such that no further duplicate packets are sent out. In addition, we propose a route-selection policy to reduce end-to-end transmission delay by sending out probe packets along the paths. For the purpose of demonstration, we implement the mechanism on Linux platform. Through the measurements from the experiment, we have shown that the proposed mechanism can improve the throughput and solve the packet retransmission problem while handoffs.

[pt] Em redes IP com mobilidade, uma conexão de transporte estabelecida com um dispositivo móvel pode ser interrompida devido a uma possível troca do endereço IP ocasionada por uma mudança de rede. O período compreendido entre o instante em que dispositivo percebe que está mudando de rede - momento em que se inicia o processo de alteração de seu endereçamento IP - até o momento do restabelecimento de suas conexões com outros dispositivos chama-se período de handoff, e sua duração é denominada latência do handoff. Existem especificações de protocolos que permitem que os nós móveis continuem acessíveis enquanto se movimentam na rede IPv6, como o MIPv6 (Mobility for IPv6). Porém, mesmo com a utilização do MIPv6, durante o período de handoff, pacotes trocados com o dispositivo móvel que se deslocou podem sofrer atrasos maiores do que o desejado ou até mesmo serem perdidos. Esse efeito acaba por diminuir a qualidade da comunicação, especialmente quando se está lidando com dados multimídia. O foco do presente trabalho é a implementação do protocolo Host Identity Protocol (HIP) numa ferramenta de simulação e a avaliação desse protocolo com o objetivo de estabelecer, de maneira quantitativa, o impacto do rompimento e restabelecimento da comunicação em ambientes móveis. A proposta do protocolo HIP é garantir a mobilidade usando uma nova identidade para os hosts de forma independente do endereço IP. São estudados, por meio de simulação, a latência e a perda de pacotes durante o handoff do protocolo HIP com o intuito de fundamentar novas investigações. / [en] In mobile IP networks, a connection of transport established with a mobile device may be interrupted due to a possible exchange of IP addresses caused by a change of network. The period between the moment when device realizes that the network is changing - time in which begins the process of changing its IP address - until the moment that it restores all connections with other devices is called period of handoff, and this period is called the latency of handoff . Some protocols specifications allow us to remain accessible while mobile move in IPv6 network, as the MIPv6 (Mobility for IPv6). But even with the use of MIPv6, during the handoff, exchanged packages with the mobile device could be delayed more than desired or even be lost. This effect diminish the quality of communication, especially when it is dealing with multimedia data. The focus of this work is the implementation of the Protocol Host Identity Protocol (HIP) in a tool for simulation to evaluate the protocol with the goal of establishing, quantitative way, the impact of disruption and restoration of communication in mobile environments. The proposed protocol ensures the mobility using a new identity for the hosts that is independent IP address. The latency and loss of packages are studied, by simulation, during the handoff of HIP protocol in order to justify further investigation.

This thesis consists of theoretical and practical parts. The theoretical part contains an analysis of the problems of wireless networkssolutions individual standards and methodologies to ensure quality of service. In the practical part using the OPNET Modeler, a number of different simulation models and their evaluation. It is a model of individual standards, support mobility and interference effects on quality of service.