A quality of service architecture for WLAN-wired networks to enhance multimedia support

Includes abstract.Includes bibliographical references (leaves 77-84).The use of WLAN for the provision of IP multimedia services faces a number of challenges which include quality of service (QoS). Because WLAN users access multimedia services usually over a wired backbone, attention must be paid to QoS over the integrated WLAN-wired network. This research focuses on the provision of QoS to WLAN users accessing multimedia services over a wired backbone. In this thesis, the IEEE 802.11-2007 enhanced data channel access (EDCA) mechanism is used to provide prioritized QoS on the WLAN media access control (MAC) layer, while weighted round robin (WRR) queue scheduling is used to provide prioritized QoS at the IP layer. The inter-working of the EDCA scheme in the WLAN and the WRR scheduling scheme in the wired network provides end-to-end QoS on a WLAN-wired IP network. A mapping module is introduced to enable the inter-working of the EDCA and WRR mechanisms

User-Centric Quality of Service Provisioning in IP Networks

The Internet has become the preferred transport medium for almost every type of communication, continuing to grow, both in terms of the number of users and delivered services. Efforts have been made to ensure that time sensitive applications receive sufficient resources and subsequently receive an acceptable Quality of Service (QoS). However, typical Internet users no longer use a single service at a given point in time, as they are instead engaged in a multimedia-rich experience, comprising of many different concurrent services. Given the scalability problems raised by the diversity of the users and traffic, in conjunction with their increasing expectations, the task of QoS provisioning can no longer be approached from the perspective of providing priority to specific traffic types over coexisting services; either through explicit resource reservation, or traffic classification using static policies, as is the case with the current approach to QoS provisioning, Differentiated Services (Diffserv). This current use of static resource allocation and traffic shaping methods reveals a distinct lack of synergy between current QoS practices and user activities, thus highlighting a need for a QoS solution reflecting the user services. The aim of this thesis is to investigate and propose a novel QoS architecture, which considers the activities of the user and manages resources from a user-centric perspective. The research begins with a comprehensive examination of existing QoS technologies and mechanisms, arguing that current QoS practises are too static in their configuration and typically give priority to specific individual services rather than considering the user experience. The analysis also reveals the potential threat that unresponsive application traffic presents to coexisting Internet services and QoS efforts, and introduces the requirement for a balance between application QoS and fairness. This thesis proposes a novel architecture, the Congestion Aware Packet Scheduler (CAPS), which manages and controls traffic at the point of service aggregation, in order to optimise the overall QoS of the user experience. The CAPS architecture, in contrast to traditional QoS alternatives, places no predetermined precedence on a specific traffic; instead, it adapts QoS policies to each individual’s Internet traffic profile and dynamically controls the ratio of user services to maintain an optimised QoS experience. The rationale behind this approach was to enable a QoS optimised experience to each Internet user and not just those using preferred services. Furthermore, unresponsive bandwidth intensive applications, such as Peer-to-Peer, are managed fairly while minimising their impact on coexisting services. The CAPS architecture has been validated through extensive simulations with the topologies used replicating the complexity and scale of real-network ISP infrastructures. The results show that for a number of different user-traffic profiles, the proposed approach achieves an improved aggregate QoS for each user when compared with Best effort Internet, Traditional Diffserv and Weighted-RED configurations. Furthermore, the results demonstrate that the proposed architecture not only provides an optimised QoS to the user, irrespective of their traffic profile, but through the avoidance of static resource allocation, can adapt with the Internet user as their use of services change.France Teleco

Implementation and Performance Evaluation of an NGN prototype using WiMax as an Access Technology

Telecommunications networks have evolved to IP-based networks, commonly known as Next Generation Networks (NGN). The biggest challenge in providing high quality realtime multimedia applications is achieving a Quality of Service (QoS) consistent with user expectations. One of the key additional factors affecting QoS is the existence of different QoS mechanisms on the heterogeneous technologies used on NGN platforms. This research investigates the techniques used to achieve consistent QoS on network technologies that use different QoS techniques. Numerous proposals for solving the end-to-end QoS problem in IP networks have adopted policy-based management, use of signalling protocols for communicating applications QoS requirements across different Network Elements and QoS provisioning in Network Elements. Such solutions are dependent on the use of traffic classification and knowledge of the QoS requirements of applications and services on the networks. This research identifies the practical difficulties involved in meeting the QoS requirements of network traffic between WiMax and an IP core network. In the work, a solution based on the concept of class-of-service mapping is proposed. In the proposed solution, QoS is implemented on the two networks and the concept of class-of-service mapping is used to integrate the two QoS systems. This essentially provides consistent QoS to applications as they traverse the two network domains and hence meet end-user QoS expectations. The work is evaluated through a NGN prototype to determine the capabilities of the networks to deliver real-time media that meets user expectations

Video Conference as a tool for Higher Education

The book describes the activities of the consortium member institutions in the framework of the TEMPUS IV Joint Project ViCES - Video Conferencing Educational Services (144650-TEMPUS-2008-IT-JPGR). In order to provide the basis for the development of a distance learning environment based on video conferencing systems and develop a blended learning courses methodology, the TEMPUS Project VICES (2009-2012) was launched in 2009. This publication collects the conclusion of the project and it reports the main outcomes together with the approach followed by the different partners towards the achievement of the project's goal. The book includes several contributions focussed on specific topics related to videoconferencing services, namely how to enable such services in educational contexts so that, the installation and deployment of videoconferencing systems could be conceived an integral part of virtual open campuses

An H.323-based adaptive QoS architecture

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Building Programmable Wireless Networks: An Architectural Survey

In recent times, there have been a lot of efforts for improving the ossified Internet architecture in a bid to sustain unstinted growth and innovation. A major reason for the perceived architectural ossification is the lack of ability to program the network as a system. This situation has resulted partly from historical decisions in the original Internet design which emphasized decentralized network operations through co-located data and control planes on each network device. The situation for wireless networks is no different resulting in a lot of complexity and a plethora of largely incompatible wireless technologies. The emergence of "programmable wireless networks", that allow greater flexibility, ease of management and configurability, is a step in the right direction to overcome the aforementioned shortcomings of the wireless networks. In this paper, we provide a broad overview of the architectures proposed in literature for building programmable wireless networks focusing primarily on three popular techniques, i.e., software defined networks, cognitive radio networks, and virtualized networks. This survey is a self-contained tutorial on these techniques and its applications. We also discuss the opportunities and challenges in building next-generation programmable wireless networks and identify open research issues and future research directions.Comment: 19 page

A differentiated quality of service oriented multimedia multicast protocol

Les systèmes de communication multimédia modernes aspirent à fournir de nouveaux services tels que des communications multipoints. Néanmoins, l'apparition de dispositifs multimédias très diversifiés et le nombre croissant de clients ont révélé de nouveaux besoins pour les mécanismes et les protocoles. Dans une communication multimédia, les flux présentent des contraintes différentes et la QdS requise pour chaque flux n'est pas la même. De plus, dans une communication multipoint, tous les utilisateurs ne peuvent pas ou ne sont pas capables de recevoir la même QdS ; cette contrainte implique que les nouveaux mécanismes de communication doivent prendre en compte les besoins des utilisateurs pour fournir un service adéquat à chaque utilisateur, surtout pour éviter le gaspillage des ressources réseau. Cette thèse propose une architecture multipoint à QdS différentiée appelée M-FPTP. Basée sur des proxies client/serveur, elle relie plusieurs LANs multipoints à travers des liens point-à-point partiellement fiables. Cette architecture fournit une QdS différente à chaque LAN dépendant des besoins des utilisateurs. Pour ce faire, nous proposons un modèle du réseau appelé Arbre Hiérarchisé (AH) qui représente en même temps les performances du réseau et les contraintes de QdS des utilisateurs. Nonobstant, l'application de méthodes standard pour la création d'arbres sur un AH peut conduire à des problèmes de surcharge du degré de sortie dans la source. Pour résoudre ce problème, nous proposons alors un nouvel algorithme appelé Arbre de Plus Courts Chemins à Degré de Sortie Limité. Le déploiement de ce service nécessite, pour gérer les utilisateurs et le déploiement correct des proxies, un nouveau protocole appelé Protocole Simple de Session pour QdS multipoint. L'ensemble des solutions proposées a été modélisé, vérifié, validé et testé en utilisant UML 2.0 et l'outil TAU G2. ABSTRACT : Modern multimedia (MM) communication systems aim to provide new services such as multicast (MC) communication. But the rising of new very different MM capable devices and the growing number of clients drive to new requirements for mechanisms and protocols. In a MM communication, there are some flows that have constraints different from others and the required QoS for each flow is not the same. Furthermore, in MC communications, all the users do not want or are not able to receive the same QoS. These constraints imply that new communication mechanisms have to take into account the user requirements in order to provide an ad hoc service to each user and to avoid wasting the network resources. This dissertation proposes a new differentiated QoS multicast architecture, based on client/server proxies, called M-FPTP, which relays many MC LANs by single partially reliable links. This architecture provides a different QoS to each LAN depending on the users requirements. For doing so, it is also provided a network model called Hierarchized Graph (HG) which represents at the same time the network performances and the users QoS constraints. Nevertheless, the application of standard tree creation methods on an HG can lead to source overloading problems. It is then proposed a new algorithm called Degree-Bounded Shortest-Path-Tree (DgB-SPT) which solves this problem. However, the deployment of such a service needs a new protocol in order to collect users requirements and correctly deploy the proxies. This protocol is called Simple Session Protocol for QoS MC (SSP-QoM). The proposed solutions have been modeled, verified, validated and tested by using UML 2.0 and TAU G2 CASE tool

MOBILITY SUPPORT ARCHITECTURES FOR NEXT-GENERATION WIRELESS NETWORKS

With the convergence of the wireless networks and the Internet and the booming demand for multimedia applications, the next-generation (beyond the third generation, or B3G) wireless systems are expected to be all IP-based and provide real-time and non-real-time mobile services anywhere and anytime. Powerful and efficient mobility support is thus the key enabler to fulfil such an attractive vision by supporting various mobility scenarios. This thesis contributes to this interesting while challenging topic. After a literature review on mobility support architectures and protocols, the thesis starts presenting our contributions with a generic multi-layer mobility support framework, which provides a general approach to meet the challenges of handling comprehensive mobility issues. The cross-layer design methodology is introduced to coordinate the protocol layers for optimised system design. Particularly, a flexible and efficient cross-layer signalling scheme is proposed for interlayer interactions. The proposed generic framework is then narrowed down with several fundamental building blocks identified to be focused on as follows. As widely adopted, we assume that the IP-based access networks are organised into administrative domains, which are inter-connected through a global IP-based wired core network. For a mobile user who roams from one domain to another, macro (inter-domain) mobility management should be in place for global location tracking and effective handoff support for both real-time and non-real-lime applications. Mobile IP (MIP) and the Session Initiation Protocol (SIP) are being adopted as the two dominant standard-based macro-mobility architectures, each of which has mobility entities and messages in its own right. The work explores the joint optimisations and interactions of MIP and SIP when utilising the complementary power of both protocols. Two distinctive integrated MIP-SIP architectures are designed and evaluated, compared with their hybrid alternatives and other approaches. The overall analytical and simulation results shown significant performance improvements in terms of cost-efficiency, among other metrics. Subsequently, for the micro (intra-domain) mobility scenario where a mobile user moves across IP subnets within a domain, a micro mobility management architecture is needed to support fast handoffs and constrain signalling messaging loads incurred by intra-domain movements within the domain. The Hierarchical MIPv6 (HMIPv6) and the Fast Handovers for MIPv6 (FMIPv6) protocols are selected to fulfil the design requirements. The work proposes enhancements to these protocols and combines them in an optimised way. resulting in notably improved performances in contrast to a number of alternative approaches

Telecommunications Networks

This book guides readers through the basics of rapidly emerging networks to more advanced concepts and future expectations of Telecommunications Networks. It identifies and examines the most pressing research issues in Telecommunications and it contains chapters written by leading researchers, academics and industry professionals. Telecommunications Networks - Current Status and Future Trends covers surveys of recent publications that investigate key areas of interest such as: IMS, eTOM, 3G/4G, optimization problems, modeling, simulation, quality of service, etc. This book, that is suitable for both PhD and master students, is organized into six sections: New Generation Networks, Quality of Services, Sensor Networks, Telecommunications, Traffic Engineering and Routing