12 research outputs found

    Optimização de recursos para difusão em redes de próxima geração

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    Doutoramento em ElectrotecniaEsta tese aborda o problema de optimização de recursos de rede, na entrega de Serviços de Comunicação em Grupo, em Redes de PrĂłxima Geração que suportem tecnologias de difusĂŁo. De acordo com esta problemĂĄtica, sĂŁo feitas propostas que levam em atenção a evolução espectĂĄvel das redes 3G em Redes HeterogĂ©neas de PrĂłxima Geração que incluam tecnologias de difusĂŁo tais como o DVB. A optimização de recursos em ComunicaçÔes em Grupo Ă© apresentada como um desafio vertical que deve cruzar diversas camadas. As optimizaçÔes aqui propostas cobrem tanto a interface entre Aplicação e a Plataforma de Serviços para a disponibilização de serviços de comunicação em grupo, como as abstracçÔes e mapeamentos feitos na interface entre a Rede Central e a Rede de Acesso RĂĄdio. As optimizaçÔes propostas nesta tese, assumem que o caminho evolutivo na direcção de uma Rede de PrĂłxima Geração Ă© feito atravĂ©s do IP. Em primeiro lugar sĂŁo endereçadas as optimizaçÔes entre a Aplicação e a Plataforma de Serviços que jĂĄ podem ser integradas nas redes 3G existentes. Estas optimizaçÔes podem potenciar o desenvolvimento de novas e inovadoras aplicaçÔes, que atravĂ©s do uso de mecanismos de distribuição em difusĂŁo podem fazer um uso mais eficiente dos recursos de rede. De seguida sĂŁo apresentadas optimizaçÔes ao nĂ­vel da interface entre a Rede Central e a Rede de Acesso RĂĄdio que abordam a heterogeneidade das redes futuras assim como a necessidade de suportar tecnologias de difusĂŁo. É ainda considerada a possibilidade de aumentar a qualidade de serviço de serviços de difusĂŁo atravĂ©s do mapeamento do IP multicast em portadoras unidireccionais. Por forma a validar todas estas optimizaçÔes, vĂĄrios protĂłtipos foram desenvolvidos com base num router avançado para redes de acesso de prĂłxima geração. As funcionalidades e arquitectura de software desse router sĂŁo tambĂ©m aqui apresentadas.This thesis addresses the problem of optimizing network resource usage, for the delivery of Group Services, in Next Generation Networks featuring broadcast technologies. In this scope, proposals are made according to the expected evolution of 3G networks into Next Generation Heterogeneous Networks that include broadcast technologies such as DVB. Group Communication resource optimization is considered a vertical challenge that must cross several layers. The optimizations here proposed cover both Application to Service Platform interfaces for group communication services, and Core Network to Radio Access Network interface abstractions and mappings. The proposed optimizations are also presented taking into consideration network evolution path towards an All-IP based Next Generation Network. First it is addressed the Application to Service Platform optimization, which can already be deployed over 3G networks. This optimization could potentiate the development of new and innovative applications that through the use of broadcast/multicast service delivery mechanisms could be more efficient network wise. Next proposals are made on the Core Network to Radio Access Network interfaces that address the heterogeneity of future networks and consider the need to support broadcast networks. It is also considered the possibility to increase the Quality of Service of broadcast/multicast services based on the dynamic mapping of IP multicast into unicast radio bearers. In order to validate these optimizations, several prototypes were built based on an advanced access router for next generation networks. Such access router functionalities and software architecture are also presented here

    Future Trends and Challenges for Mobile and Convergent Networks

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    Some traffic characteristics like real-time, location-based, and community-inspired, as well as the exponential increase on the data traffic in mobile networks, are challenging the academia and standardization communities to manage these networks in completely novel and intelligent ways, otherwise, current network infrastructures can not offer a connection service with an acceptable quality for both emergent traffic demand and application requisites. In this way, a very relevant research problem that needs to be addressed is how a heterogeneous wireless access infrastructure should be controlled to offer a network access with a proper level of quality for diverse flows ending at multi-mode devices in mobile scenarios. The current chapter reviews recent research and standardization work developed under the most used wireless access technologies and mobile access proposals. It comprehensively outlines the impact on the deployment of those technologies in future networking environments, not only on the network performance but also in how the most important requirements of several relevant players, such as, content providers, network operators, and users/terminals can be addressed. Finally, the chapter concludes referring the most notable aspects in how the environment of future networks are expected to evolve like technology convergence, service convergence, terminal convergence, market convergence, environmental awareness, energy-efficiency, self-organized and intelligent infrastructure, as well as the most important functional requisites to be addressed through that infrastructure such as flow mobility, data offloading, load balancing and vertical multihoming.Comment: In book 4G & Beyond: The Convergence of Networks, Devices and Services, Nova Science Publishers, 201

    Infrastructure sharing of 5G mobile core networks on an SDN/NFV platform

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    When looking towards the deployment of 5G network architectures, mobile network operators will continue to face many challenges. The number of customers is approaching maximum market penetration, the number of devices per customer is increasing, and the number of non-human operated devices estimated to approach towards the tens of billions, network operators have a formidable task ahead of them. The proliferation of cloud computing techniques has created a multitude of applications for network services deployments, and at the forefront is the adoption of Software-Defined Networking (SDN) and Network Functions Virtualisation (NFV). Mobile network operators (MNO) have the opportunity to leverage these technologies so that they can enable the delivery of traditional networking functionality in cloud environments. The benefit of this is reductions seen in the capital and operational expenditures of network infrastructure. When going for NFV, how a Virtualised Network Function (VNF) is designed, implemented, and placed over physical infrastructure can play a vital role on the performance metrics achieved by the network function. Not paying careful attention to this aspect could lead to the drastically reduced performance of network functions thus defeating the purpose of going for virtualisation solutions. The success of mobile network operators in the 5G arena will depend heavily on their ability to shift from their old operational models and embrace new technologies, design principles and innovation in both the business and technical aspects of the environment. The primary goal of this thesis is to design, implement and evaluate the viability of data centre and cloud network infrastructure sharing use case. More specifically, the core question addressed by this thesis is how virtualisation of network functions in a shared infrastructure environment can be achieved without adverse performance degradation. 5G should be operational with high penetration beyond the year 2020 with data traffic rates increasing exponentially and the number of connected devices expected to surpass tens of billions. Requirements for 5G mobile networks include higher flexibility, scalability, cost effectiveness and energy efficiency. Towards these goals, Software Defined Networking (SDN) and Network Functions Virtualisation have been adopted in recent proposals for future mobile networks architectures because they are considered critical technologies for 5G. A Shared Infrastructure Management Framework was designed and implemented for this purpose. This framework was further enhanced for performance optimisation of network functions and underlying physical infrastructure. The objective achieved was the identification of requirements for the design and development of an experimental testbed for future 5G mobile networks. This testbed deploys high performance virtualised network functions (VNFs) while catering for the infrastructure sharing use case of multiple network operators. The management and orchestration of the VNFs allow for automation, scalability, fault recovery, and security to be evaluated. The testbed developed is readily re-creatable and based on open-source software

    Creation of value with open source software in the telecommunications field

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    Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200

    Convergence du web et des services de communication

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    Les services de communication, du courrier postal Ă  la tĂ©lĂ©phonie, en passant par la voix et la vidĂ©o sur IP (Internet Protocol), la messagerie Ă©lectronique, les salons de discussion sur Internet, les visioconfĂ©rences ou les tĂ©lĂ©communications immersives ont Ă©voluĂ© au fil du temps. Un systĂšme de communication voix-vidĂ©o sur IP est rĂ©alisĂ© grĂące Ă  deux couches architecturales fondamentales : la couche de signalisation et la couche mĂ©dia. Le protocole de signalisation est utilisĂ© pour crĂ©er, modifier et terminer des sessions multimĂ©dias entre des participants. La couche de signalisation est divisĂ©e en deux sous-couches - la couche de service et celle de contrĂŽle - selon la spĂ©cification de l IP Multimedia Subsystem (IMS). Deux systĂšmes de communication largement utilisĂ©s sont l IMS et SIP Pair-Ă - Pair (P2P SIP). Les fournisseurs de services, qui se comportent en tant qu intermĂ©diaires entre appelants et appelĂ©s, implĂ©mentent les systĂšmes de communication, contrĂŽlant strictement la couche signalisation. Or ces fournisseurs de services ne prennent pas en compte la diversitĂ© des utilisateurs. Cette thĂšse identifie trois barriĂšres technologiques dans les systĂšmes de communication actuels et plus prĂ©cisĂ©ment concernant la couche de signalisation. I. Un manque d ouverture et de flexibilitĂ© dans la couche de signalisation pour les utilisateurs. II. Un dĂ©veloppement difficile des services basĂ©s sur le rĂ©seau et les sessions. III. Une complexification du la couche de signalisation lors d un trĂšs grand nombre d appels. Ces barriĂšres technologiques gĂȘnent l innovation des utilisateurs avec ces services de communication. BasĂ© sur les barriĂšres technologiques listĂ©es cidessus, le but initial de cette thĂšse est de dĂ©finir un concept et une architecture de systĂšme de communication dans lequel chaque individu devient un fournisseur de service. Le concept, "My Own Communication Service Provider" (MOCSP) et le systĂšme MOCSP sont proposĂ©s, accompagnĂ© d un diagramme de sĂ©quence. Ensuite, la thĂšse fournit une analyse qui compare le systĂšme MOCSP avec les systĂšmes de communication existants en termes d ouverture et de flexibilitĂ©. La seconde partie de la thĂšse prĂ©sente des solutions pour les services basĂ©s sur le rĂ©seau ou les sessions, mettant en avant le systĂšme MOCSP proposĂ©. Deux services innovants, user mobility et partial session transfer/retrieval (PSTR) sont pris comme exemples de services basĂ©s sur le rĂ©seau ou les sessions. Les services basĂ©s sur un rĂ©seau ou des sessions interagissent avec une session ou sont exĂ©cutĂ©s dans une session. Dans les deux cas, une seule entitĂ© fonctionnelle entre l appelant et l appelĂ© dĂ©clenche le flux multimĂ©dia pendant l initialisation de l appel et/ou en cours de communication. De plus, la coopĂ©ration entre le contrĂŽle d appel rĂ©seau et les diffĂ©rents pairs est facilement rĂ©alisĂ©. La derniĂšre partie de la thĂšse est dĂ©diĂ©e Ă  l extension de MOCSP en cas de forte densitĂ© d appels, elle inclut une analyse comparative. Cette analyse dĂ©pend de quatre facteurs - limite de passage Ă  l Ă©chelle, niveau de complexitĂ©, ressources de calcul requises et dĂ©lais d Ă©tablissement de session - qui sont considĂ©rĂ©s pour Ă©valuer le passage Ă  l Ă©chelle de la couche de signalisation. L analyse comparative montre clairement que la solution basĂ©e sur MOCSP est simple et amĂ©liore l usage effectif des ressources de calcul par rapport aux systĂšmes de communication traditionnelsDifferent communication services from delivery of written letters to telephones, voice/video over Internet Protocol(IP), email, Internet chat rooms, and video/audio conferences, immersive communications have evolved over time. A communication system of voice/video over IP is the realization of a two fundamental layered architecture, signaling layer and media layer. The signaling protocol is used to create, modify, and terminate media sessions between participants. The signaling layer is further divided into two layers, service layer and service control layer, in the IP Multimedia Subsystem (IMS) specification. Two widely used communication systems are IMS, and Peer-to-Peer Session Initiation Protocol (P2P SIP). Service providers, who behave as brokers between callers and callees, implement communication systems, heavily controlling the signaling layer. These providers do not take the diversity aspect of end users into account. This dissertation identifies three technical barriers in the current communication systems especially in the signaling layer. Those are: I. lack of openness and flexibility in the signaling layer for end users. II. difficulty of development of network-based, session-based services. III. the signaling layer becomes complex during the high call rate. These technical barriers hinder the end-user innovation with communication services. Based on the above listed technical barriers, the first part of this thesis defines a concept and architecture for a communication system in which an individual user becomes the service provider. The concept, My Own Communication Service Provider (MOCSP) and MOCSP system is proposed and followed by a call flow. Later, this thesis provides an analysis that compares the MOCSP system with existing communication systems in terms of openness and flexibility. The second part of this thesis presents solutions for network-based, session based services, leveraging the proposed MOCSP system. Two innovative services, user mobility and partial session transfer/retrieval are considered as examples for network-based, session-based services. The network-based, sessionbased services interwork with a session or are executed within a session. In both cases, a single functional entity between caller and callee consistently enables the media flow during the call initiation and/or mid-call. In addition, the cooperation of network call control and end-points is easily achieved. The last part of the thesis is devoted to extending the MOCSP for a high call rate and includes a preliminary comparative analysis. This analysis depends on four factors - scalability limit, complexity level, needed computing resources and session setup latency - that are considered to specify the scalability of the signaling layer. The preliminary analysis clearly shows that the MOCSP based solution is simple and has potential for improving the effective usage of computing resources over the traditional communication systemsEVRY-INT (912282302) / SudocSudocFranceF

    A service based approach for future internet architectures

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    Doktorgradsavhandling i informasjons- og kommunikasjonsteknologi, Universitetet i Agder, Grimstad, 201

    A framework for the dynamic management of Peer-to-Peer overlays

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    Peer-to-Peer (P2P) applications have been associated with inefficient operation, interference with other network services and large operational costs for network providers. This thesis presents a framework which can help ISPs address these issues by means of intelligent management of peer behaviour. The proposed approach involves limited control of P2P overlays without interfering with the fundamental characteristics of peer autonomy and decentralised operation. At the core of the management framework lays the Active Virtual Peer (AVP). Essentially intelligent peers operated by the network providers, the AVPs interact with the overlay from within, minimising redundant or inefficient traffic, enhancing overlay stability and facilitating the efficient and balanced use of available peer and network resources. They offer an “insider‟s” view of the overlay and permit the management of P2P functions in a compatible and non-intrusive manner. AVPs can support multiple P2P protocols and coordinate to perform functions collectively. To account for the multi-faceted nature of P2P applications and allow the incorporation of modern techniques and protocols as they appear, the framework is based on a modular architecture. Core modules for overlay control and transit traffic minimisation are presented. Towards the latter, a number of suitable P2P content caching strategies are proposed. Using a purpose-built P2P network simulator and small-scale experiments, it is demonstrated that the introduction of AVPs inside the network can significantly reduce inter-AS traffic, minimise costly multi-hop flows, increase overlay stability and load-balancing and offer improved peer transfer performance
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