22 research outputs found

    Cooperative resource pooling in multihomed mobile networks

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    The ubiquity of multihoming amongst mobile devices presents a unique opportunity for users to co-operate, sharing their available Internet connectivity, forming multihomed mobile networks on demand. This model provides users with vast potential to increase the quality of service they receive. Despite this, such mobile networks are typically underutilized and overly restrictive, as additional Internet connectivity options are predominantly ignored and selected gateways are both immutable and incapable of meeting the demand of the mobile network. This presents a number of research challenges, as users look to maximize their quality of experience, while balancing both the financial cost and power consumption associated with utilizing a diverse set of heterogeneous Internet connectivity options. In this thesis we present a novel architecture for mobile networks, the contribution of which is threefold. Firstly, we ensure the available Internet connectivity is appropriately advertised, building a routing overlay which allows mobile devices to access any available network resource. Secondly, we leverage the benefits of multipath communications, providing the mobile device with increased throughput, additional resilience and seamless mobility. Finally, we provide a multihomed framework, enabling policy driven network resource management and path selection on a per application basis. Policy driven resource management provides a rich and descriptive approach, allowing the context of the network and the device to be taken into account when making routing decisions at the edge of the Internet. The aim of this framework, is to provide an efficient and flexible approach to the allocation of applications to the optimal network resource, no matter where it resides in a mobile network. Furthermore, we investigate the benefits of path selection, facilitating the policy framework to choose the optimal network resource for specific applications. Through our evaluation, we prove that our approach to advertising Internet connectivity in a mobile network is both efficient and capable of increasing the utilization of the available network capacity. We then demonstrate that our policy driven approach to resource management and path selection can further improve the user’s quality of experience, by tailoring network resource usage to meet their specific needs

    Survivability, Scalability and Security of Mobility Protocols

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    Today mobile computing has become a necessity and we are witnessing explosive growth in the number of mobile devices accessing the Internet. To facilitate continuous Internet connectivity for nodes and networks in motion, mobility protocols are required and they exchange various signaling messages with the mobility infrastructure for protocol operation. Proliferation in mobile computing has raised several research issues for the mobility protocols. First, it is essential to perform cost and scalability analysis of mobility protocols to find out their resource requirement to cope with future expansion. Secondly, mobility protocols have survivability issues and are vulnerable to security threats, since wireless communication media can be easily accessible to intruders. The third challenge in mobile computing is the protection ofsignaling messages against losses due to high bandwidth requirementof multimedia in mobile environments. However, there is lack of existing works that focus on the quantitative analysis of cost, scalability, survivability and security of mobility protocols.In this dissertation, we have performed comprehensive evaluation ofmobility protocols. We have presented tools and methodologies required for the cost, scalability, survivability and security analysis of mobilityprotocols. We have proposed a dynamic scheduling algorithm to protect mobility signaling message against losses due to increased multimedia traffic in mobile environments and have also proposed a mobile networkarchitecture that aims at maximizing bandwidth utilization. The analysis presented in this work can help network engineers compare different mobility protocols quantitatively, thereby choose one that is reliable, secure, survivable and scalable

    MP-CFM: MPTCP-Based communication functional module for next generation ERTMS

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    184 p. El contenido de los capítulos 4,5,6,7,8 y 9 está sujeto a confidencialidadEl Sistema Europeo de Gestión del Tráfico Ferroviario (ERTMS, por sus siglasen inglés), fue originalmente diseñado para los ferrocarriles europeos. Sinembargo, a lo largo de las dos últimas décadas, este sistema se ha convertidoen el estándar de-facto para los servicios de Alta Velocidad en la mayoría depaíses desarrollados.El sistema ERTMS se compone de tres subsistemas principales: 1) el Sistemade Control Ferroviario Europeo (ETCS, por sus siglas en inglés), que actúacomo aplicación de señalización; 2) el sistema Euroradio, que a su vez estádividido en dos subsistemas, el Módulo de Seguridad Funcional (SFM, porsus siglas en inglés), y el Módulo de Comunicación Funcional (CFM, porsus siglas en inglés); y 3) el sistema de comunicaciones subyacente, GSM-R,que transporta la información intercambiada entre el sistema embarcado enel tren (OBU, por sus siglas en inglés) y el Centro de Bloqueo por Radio(RBC, por sus siglas en inglés). El sistema de señalización ETCS soporta tresniveles dependiendo del nivel de prestaciones soportadas. En el nivel 3 seintroduce la posibilidad de trabajar con bloques móviles en lugar de bloquesfijos definidos en la vía. Esto implica que la distancia de avance entre dos trenesconsecutivos puede ser reducida a una distancia mínima en la que se garanticela seguridad del servicio, aumentando por tanto la capacidad del corredorferroviario. Esta distancia de seguridad viene determinada por la combinaciónde la distancia de frenado del tren y el retraso de las comunicaciones deseñalización. Por lo tanto, se puede afirmar que existe una relación directaentre los retrasos y la confiabilidad de las transmisiones de las aplicaciones deseñalización y la capacidad operacional de un corredor ferroviario. Así pues,el estudio y mejora de los sistemas de comunicaciones utilizados en ERTMSjuegan un papel clave en la evolución del sistema ERTMS. Asimismo, unaoperatividad segura en ERTMS, desde el punto de vista de las comunicacionesimplicadas en la misma, viene determinada por la confiabilidad de lascomunicaciones, la disponibilidad de sus canales de comunicación, el retrasode las comunicaciones y la seguridad de sus mensajes.Unido este hecho, la industria ferroviaria ha venido trabajando en ladigitalización y la transición al protocolo IP de la mayor parte de los sistemasde señalización. Alineado con esta tendencia, el consorcio industrial UNISIGha publicado recientemente un nuevo modelo de comunicaciones para ERTMSque incluye la posibilidad, no solo de operar con el sistema tradicional,basado en tecnología de conmutación de circuitos, sino también con un nuevosistema basado en IP. Esta tesis está alineada con el contexto de migraciónactual y pretende contribuir a mejorar la disponibilidad, confiabilidad yseguridad de las comunicaciones, tomando como eje fundamental los tiemposde transmisión de los mensajes, con el horizonte puesto en la definición deuna próxima generación de ERTMS, definida en esta tesis como NGERTMS.En este contexto, se han detectado tres retos principales para reforzar laresiliencia de la arquitectura de comunicaciones del NGERTMS: 1) mejorarla supervivencia de las comunicaciones ante disrupciones; 2) superar laslimitaciones actuales de ERTMS para enviar mensajes de alta prioridad sobretecnología de conmutación de paquetes, dotando a estos mensajes de un mayorgrado de resiliencia y menor latencia respecto a los mensajes ordinarios; y3) el aumento de la seguridad de las comunicaciones y el incremento de ladisponibilidad sin que esto conlleve un incremento en la latencia.Considerando los desafíos previamente descritos, en esta tesis se proponeuna arquitectura de comunicaciones basada en el protocolo MPTCP, llamadaMP-CFM, que permite superar dichos desafíos, a la par que mantener laretrocompatibilidad con el sistema de comunicaciones basado en conmutaciónde paquetes recientemente propuesto por UNISIG. Hasta el momento, esta esla primera vez que se propone una arquitectura de comunicaciones completacapaz de abordar los desafíos mencionados anteriormente. Esta arquitecturaimplementa cuatro tipos de clase de servicio, los cuales son utilizados porlos paquetes ordinarios y de alta prioridad para dos escenarios distintos; unescenario en el que ambos extremos, el sistema embarcado o OBU y el RBC,disponen de múltiples interfaces de red; y otro escenario transicional en el cualel RBC sí tiene múltiples interfaces de red pero el OBU solo dispone de unaúnica interfaz. La arquitectura de comunicaciones propuesta para el entornoferroviario ha sido validada mediante un entorno de simulación desarrolladopara tal efecto. Es más, dichas simulaciones demuestran que la arquitecturapropuesta, ante disrupciones de canal, supera con creces en términos derobustez el sistema diseñado por UNISIG. Como conclusión, se puede afirmarque en esta tesis se demuestra que una arquitectura de comunicaciones basadade MPTCP cumple con los exigentes requisitos establecidos para el NGERTMSy por tanto dicha propuesta supone un avance en la evolución del sistema deseñalización ferroviario europeo

    Ubiquitous communications for wireless personal area networks in a heterogeneous environment

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    The widespread use of wireless technologies has led to a tremendous development in wireless communication systems. Currently, an individual mobile user may carry multiple personal devices with multiple wireless interfaces, which can interconnect with each other to form a Wireless Personal Area Network (WPAN) which moves with this user. These devices exist in a heterogeneous environment which is composed of various wireless networks with differing coverage and access technologies and also the topology, device conditions and wireless connections in the WPAN may be dynamically changing. Such individual mobile users require ubiquitous communications anytime, anywhere, with any device and wish content to be efficiently and continuously transferred across the various wireless networks both outside and inside WPANs, wherever they move. This thesis presents research carried out into how to implement ubiquitous communications for WPANs in such an environment. Two main issues are considered. The first is how to initiate content transfer and keep it continuous, no matter which wireless network is used as a user moves or how the WPAN changes dynamically. The second is how to implement this transfer in the most efficient way: selecting the most suitable transfer mode for a WPAN according to the user’s and application’s requirements. User-centric (personal-area-centric) and contentcentric mechanisms are proposed in this thesis to address these issues. A scheme based on a Personal Distributed Environment (PDE) concept and designed as a logical user-based management entity is presented. This is based on three mechanisms which are proposed to overcome the technical problems in practical scenarios, which cannot be solved by existing approaches. A novel mechanism is proposed to combine local direct and global mobile communications, in order to implement ubiquitous communications in both infrastructure-less and infrastructurebased networks. This enables an individual user’s ubiquitous communications to be initiated in an infrastructure-less network environment and kept continuous when they move across infrastructure-based networks. Its advantages are evaluated by a performance analysis model and compared to existing solutions and verified by experiments. A cooperation and management scheme is also proposed for dynamic changes of multiple mobile routers and flexible switching of personal device roles in a WPAN while keeping ongoing ubiquitous communications continuous. This adopts a novel view of WPANs which solves the addressing problems caused by changes of mobile routers and makes these transparent to personal devices in the WPAN and external content sources. It provides an efficient method for changing the mobile router of a single WPAN or a WPAN merging with another moving network. Its benefits are demonstrated through performance analysis models. Finally, a novel user-centric and contentcentric mechanism for decision making, to select the most appropriate mobile router in a dynamically changing WPAN environment is proposed. This selects the most suitable content transfer mode for the WPAN to fulfil an individual user’s various requirements. It has different strategies to suit various types of applications. Selection results are demonstrated to verify the proposed mechanism in multiple scenarios of changing user requirements, applications and WPAN conditions

    IP Mobility Support in Multi-hop Vehicular Communications Networks

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    The combination of infrastructure-to-vehicle and vehicle-to-vehicle communications, namely the multi-hop Vehicular Communications Network (VCN) , appears as a promising solution for the ubiquitous access to IP services in vehicular environments. In this thesis, we address the challenges of multi-hop VCN, and investigate the seamless provision of IP services over such network. Three different schemes are proposed and analyzed. First, we study the limitations of current standards for the provision of IP services, such as 802.11p/WAVE, and propose a framework that enables multi-hop communications and a robust IP mobility mechanism over WAVE. An accurate analytical model is developed to evaluate the throughput performance, and to determine the feasibility of the deployment of IP-based services in 802.11p/WAVE networks. Next, the IP mobility support is extended to asymmetric multi-hop VCN. The proposed IP mobility and routing mechanisms react to the asymmetric links, and also employ geographic location and road traffic information to enable predictive handovers. Moreover, since multi-hop communications suffer from security threats, it ensures that all mobility signalling is authenticated among the participant vehicles. Last, we extend our study to a heterogeneous multi-hop VCN, and propose a hybrid scheme that allows for the on-going IP sessions to be transferred along the heterogeneous communications system. The proposed global IP mobility scheme focuses on urban vehicular scenarios, and enables seamless communications for in-vehicle networks, commuters, and pedestrians. The overall performance of IP applications over multi-hop VCN are improved substantially by the proposed schemes. This is demonstrated by means of analytical evaluations, as well as extensive simulations that are carried out in realistic highway and urban vehicular scenarios. More importantly, we believe that our dissertation provides useful analytical tools, for evaluating the throughput and delay performance of IP applications in multi-hop vehicular environments. In addition, we provide a set of practical and efficient solutions for the seamless support of IP tra c along the heterogeneous and multi-hop vehicular network, which will help on achieving ubiquitous drive-thru Internet, and infotainment traffic access in both urban and highway scenarios

    IP Mobility in Wireless Operator Networks

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    Wireless network access is gaining increased heterogeneity in terms of the types of IP capable access technologies. The access network heterogeneity is an outcome of incremental and evolutionary approach of building new infrastructure. The recent success of multi-radio terminals drives both building a new infrastructure and implicit deployment of heterogeneous access networks. Typically there is no economical reason to replace the existing infrastructure when building a new one. The gradual migration phase usually takes several years. IP-based mobility across different access networks may involve both horizontal and vertical handovers. Depending on the networking environment, the mobile terminal may be attached to the network through multiple access technologies. Consequently, the terminal may send and receive packets through multiple networks simultaneously. This dissertation addresses the introduction of IP Mobility paradigm into the existing mobile operator network infrastructure that have not originally been designed for multi-access and IP Mobility. We propose a model for the future wireless networking and roaming architecture that does not require revolutionary technology changes and can be deployed without unnecessary complexity. The model proposes a clear separation of operator roles: (i) access operator, (ii) service operator, and (iii) inter-connection and roaming provider. The separation allows each type of an operator to have their own development path and business models without artificial bindings with each other. We also propose minimum requirements for the new model. We present the state of the art of IP Mobility. We also present results of standardization efforts in IP-based wireless architectures. Finally, we present experimentation results of IP-level mobility in various wireless operator deployments.Erilaiset langattomat verkkoyhteydet lisääntyvät Internet-kykyisten teknologioiden muodossa. Lukuisten eri teknologioiden päällekkäinen käyttö johtuu vähitellen ja tarpeen mukaan rakennetusta verkkoinfrastruktuurista. Useita radioteknologioita (kuten WLAN, GSM ja UMTS) sisältävien päätelaitteiden (kuten älypuhelimet ja kannettavat tietokoneet) viimeaikainen kaupallinen menestys edesauttaa uuden verkkoinfrastruktuurin rakentamista, sekä mahdollisesti johtaa verkkoteknologioiden kirjon lisääntymiseen. Olemassa olevaa verkkoinfrastruktuuria ei kaupallisista syistä kannata korvata uudella teknologialla yhdellä kertaa, vaan vaiheittainen siirtymävaihe kestää tyypillisesti useita vuosia. Internet-kykyiset päätelaitteet voivat liikkua joko saman verkkoteknologian sisällä tai eri verkkoteknologioiden välillä. Verkkoympäristöstä riippuen liikkuvat päätelaitteet voivat liittyä verkkoon useiden verkkoyhteyksien kautta. Näin ollen päätelaite voi lähettää ja vastaanottaa tietoliikennepaketteja yhtäaikaisesti lukuisia verkkoja pitkin. Tämä väitöskirja käsittelee Internet-teknologioiden liikkuvuutta ja näiden teknologioiden tuomista olemassa oleviin langattomien verkko-operaattorien verkkoinfrastruktuureihin. Käsiteltäviä verkkoinfrastruktuureita ei alun perin ole suunniteltu Internet-teknologian liikkuvuuden ja monien yhtäaikaisten yhteyksien ehdoilla. Tässä työssä ehdotetaan tulevaisuuden langattomien verkkojen arkkitehtuurimallia ja ratkaisuja verkkovierailujen toteuttamiseksi. Ehdotettu arkkitehtuuri voidaan toteuttaa ilman mittavia teknologisia mullistuksia. Mallin mukaisessa ehdotuksessa verkko-operaattorin roolit jaetaan selkeästi (i) verkko-operaattoriin, (ii) palveluoperaattoriin ja (iii) yhteys- sekä verkkovierailuoperaattoriin. Roolijako mahdollistaa sen, että kukin operaattorityyppi voi kehittyä itsenäisesti, ja että teennäiset verkkoteknologiasidonnaisuudet poistuvat palveluiden tuottamisessa. Työssä esitetään myös alustava vaatimuslista ehdotetulle mallille, esimerkiksi yhteysoperaattorien laatuvaatimukset. Väitöskirja esittelee myös liikkuvien Internet-teknologioiden viimeisimmän kehityksen. Työssä näytetään lisäksi standardointituloksia Internet-kykyisissä langattomissa arkkitehtuureissa

    Connecting vehicular networks to the internet : a life time-based routing protocol

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    Inter-Vehicle Communications have recently attracted the attention of researchers in academia and industry. In such networks, vehicles should be able to communicate among each other (V2V) as well as with roadside Infrastructure units (V2I). Vehicular networks try to provide safety on the roads by disseminating critical messages among vehicles. Infrastructure units provide some services such as driver information systems and Internet access. Because of the high speed and high mobility of vehicles, establishing and maintaining a connection to these units is very challenging. We introduce a new protocol that uses the characteristics of vehicle movements to predict the vehicle behavior and select a route with the longest life-time to connect to the wired network. It aims at spreading the advertisement messages through multi-hops without flooding the network, do seamless hand-overs and select the most stable routes to these units. We performed some simulations and compared the performance of our work with some well-known protocols

    Algorithmes d'adressage et routage pour des réseaux fortement mobiles à grande échelle

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    After successfully connecting machines and people later (world wide web), the new era of In-ternet is about connecting things. Due to increasing demands in terms of addresses, mobility, scalability, security and other new unattended challenges, the evolution of current Internet archi-tecture is subject to major debate worldwide. The Internet Architecture Board (IAB) workshop on Routing and Addressing report described the serious scalability problems faced by large backbone operators in terms of routing and addressing, illustrated by the unsustainable growth of the Default Free Zone (DFZ) routing tables. Some proposals tackled the scalability and IP semantics overload issues with two different approaches: evolutionary approach (backward com-patibility) or a revolutionary approach. Several design objectives (technical or high-level) guided researchers in their proposals. Mobility is definitely one of the main challenges.Inter-Vehicle Communication (IVC) attracts considerable attention from the research com-munity and the industry for its potential in providing Intelligent Transportation Systems (ITS) and passengers services. Vehicular Ad-Hoc Networks (VANETs) are emerging as a class of wire-less network, formed between moving vehicles equipped with wireless interfaces (cellular and WiFi) employing heterogeneous communication systems. A VANET is a form of mobile ad-hoc network that provides IVC among nearby vehicles and may involve the use of a nearby fixed equipment on the roadside. The impact of Internet-based vehicular services (infotainment) are quickly developing. Some of these applications, driver assistance services or traffic reports, have been there for a while. But market-enabling applications may also be an argument in favor of a more convenient journey. Such use cases are viewed as a motivation to further adoption of the ITS standards developed within IEEE, ETSI, and ISO.This thesis focuses on applying Future Internet paradigm to vehicle-to-Internet communica-tions in an attempt to define the solution space of Future Vehicular Internet. We first introduce two possible vehicle-to-Internet use cases and great enablers for IP based services : eHealth and Fully-electric Vehicles. We show how to integrate those use cases into IPv6 enabled networks. We further focus on the mobility architectures and determine the fundamental components of a mobility architecture. We then classify those approaches into centralized and distributed to show the current trends in terms of network mobility extension, an essential component to vehicular networking. We eventually analyze the performance of these proposals. In order to define an identifier namespace for vehicular communications, we introduce the Vehicle Identification Numbers are possible candidates. We then propose a conversion algorithm that preserves the VIN characteristics while mapping it onto usable IPv6 networking objects (ad-dresses, prefixes, and Mobile Node Identifiers). We make use of this result to extend LISP-MN protocol with the support of our VIN6 addressing architecture. We also apply those results to group IP-based communications, when the cluster head is in charge of a group of followers.Cette thèse a pour objectif de faire avancer l'état de l'art des communications basée sur Internet Protocol version 6 (IPv6) dans le domaine des réseaux véhiculaires, et ce dans le cadre des évolutions récentes de IP, notamment l'avènement du Future Internet. Le Future Internet (F.I.) définit un ensemble d'approches pour faire évoluer l'Internet actuel , en particulier l'émergence d'un Internet mobile exigeant en ressources. Les acteurs de ce domaine définissent les contraintes inhérentes aux approches utilisées historiquement dans l'évolution de l'architecture d'Internet et tentent d'y remédier soit de manière évolutive soit par une rupture technologique (révolutionnaire). Un des problèmes au centre de cette nouvelle évolution d'Internet est la question du nommage et de l'adressage dans le réseau. Nous avons entrepris dans cette thèse l'étude de ce problème, dans le cadre restreint des communications véhiculaires Internet.Dans ce contexte, l'état de l'art du Future Internet a mis en avant les distinctions des approches révolutionnaires comparées aux propositions évolutives basées sur IPv6. Les réseaux véhiculaires étant d'ores-et-déjà dotés de piles protocolaires comprenant une extension IPv6, nous avons entamé une approche évolutive visant à intégrer les réseaux véhiculaires au Future Internet. Une première proposition a été de convertir un identifiant présent dans le monde automobile (VIN, Numéro d'Identification de Véhicule) en un lot d'adresses réseau propres à chaque véhicule (qui est donc propriétaire de son adressage issu de son identifiant). Cette proposition étant centrée sur le véhicule, nous avons ensuite intégré ces communications basés dans une architecture globale Future Internet basée sur IPv6 (protocole LISP). En particulier, et avec l'adressage VIN, nous avons défini un espace d'adressage indépendant des fournisseurs d'accès à Internet où le constructeur automobile devient acteur économique fournissant des services IPv6 à sa flotte de véhicules conjointement avec les opérateurs réseau dont il dépend pour transporter son trafic IP. Nous nous sommes ensuite intéressés à l'entourage proche du véhicule afin de définir un nouveau mode de communication inter-véhiculaire à Internet: le V2V2I (Angl. Vehicle-to-Vehicle-to-Infrastructure). Jusqu'à présent, les modes de transmission de données à Internet dans le monde du véhicule consistaient en des topologies V2I, à savoir véhicule à Internet, où le véhicule accède à l'infrastructure directement sans intermédiaire. Dans le cadre des communications véhiculaires à Internet, nous proposons une taxonomie des méthodes existantes dans l'état de l'art. Les techniques du Future Internet étant récentes, nous avons étendu notre taxonomie par une nouvelle approche basée sur la séparation de l'adressage topologique dans le cluster de celui de l'infrastructure. Le leader du cluster s'occupe d'affecter les adresses (de son VIN) et de gérer le routage à l'intérieur de son cluster. La dernière contribution consiste en la comparaison des performances des protocoles de gestion de mobilité, notamment pour les réseaux de véhicules et des communications de type vehicule-à-Internet. Dans ce cadre, nous avons proposé une classification des protocoles de gestion de mobilité selon leur déploiement: centralisé (basé réseau ou host) et distribué. Nous avons ensuite évalué les performances en modélisant les durées de configurations et de reconfigurations des différents protocoles concernés

    Hierarchical network topographical routing

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    Within the last 10 years the content consumption model that underlies many of the assumptions about traffic aggregation within the Internet has changed; the previous short burst transfer followed by longer periods of inactivity that allowed for statistical aggregation of traffic has been increasingly replaced by continuous data transfer models. Approaching this issue from a clean slate perspective; this work looks at the design of a network routing structure and supporting protocols for assisting in the delivery of large scale content services. Rather than approaching a content support model through existing IP models the work takes a fresh look at Internet routing through a hierarchical model in order to highlight the benefits that can be gained with a new structural Internet or through similar modifications to the existing IP model. The work is divided into three major sections: investigating the existing UK based Internet structure as compared to the traditional Autonomous System (AS) Internet structural model; a localised hierarchical network topographical routing model; and intelligent distributed localised service models. The work begins by looking at the United Kingdom (UK) Internet structure as an example of a current generation technical and economic model with shared access to the last mile connectivity and a large scale wholesale network between Internet Service Providers (ISPs) and the end user. This model combined with the Internet Protocol (IP) address allocation and transparency of the wholesale network results in an enforced inefficiency within the overall network restricting the ability of ISPs to collaborate. From this model a core / edge separation hierarchical virtual tree based routing protocol based on the physical network topography (layers 2 and 3) is developed to remove this enforced inefficiency by allowing direct management and control at the lowest levels of the network. This model acts as the base layer for further distributed intelligent services such as management and content delivery to enable both ISPs and third parties to actively collaborate and provide content from the most efficient source
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