IMS evolution and IMS test-bed service platforms

The paper presents the future trends in network evolution and multimedia services provision and delivery. In the context of Next Generation Networks vision, Mobile and Fixed access networks converge over the IP Multimedia Subsystem (IMS) platform that will control the delivery of user-centric secure broadband quad-play services. The IMS has been well defined for the mobile world; however its integration with fixed line networks requires extended functionalities in the architecture, application and security planes. This study is concerned with the research efforts for extending IMS in order to become the common control architecture that will support the convergence of heterogeneous networks and the integration of quad-play services. Furthermore, the most up-to-date open source code IMS platforms and testing scenarios are presented. Audiovisual Media usages are moving from collective and passive approach to personal active behaviours, at home and in mobility situation outside the home. At the same time usages patterns are shifting towards non linear usages and away from the classic models of linear broadcast TV. The TV set no longer has the monopoly of delivery of Audio-Visual content, the PC and related media centres, mobile phones and potentially initiatives from new stakeholders are all becoming increasingly important. Consumer Electronics, Broadcast and Telco Industries response is extremely abundant heterogeneous terminals (Personal TV, Mobiles, Game consoles, Personal Video Players, Home media Centres, Home Gateways...) and heterogeneous networks (2.5-4G, DVB-H, T-DMB, WiMax Home network, IPTV..). In such heterogeneous environment, efficient delivery will need to optimize unicast, multicast, broadcast as well as, the new mechanisms made possible by recent advances in peer to peer grids. This situation has important consequences for the existing business models and institutions, as well as content production, content distribution and the end user experience on various terminals. In particular to stakeholders proposing services based on heterogeneous terminal and networks, with the demand from users of transparent service continuity. This paper aims to investigate the state of the art in the delivery of user-centric secure broadband multimedia services on mobile and fixed platforms. Quad-play services (Web, VoIP, IPTV, and P2P) will be provided across heterogeneous networks through a common control platform (extended IMS). Specifically, the paper addresses the issue of unified service delivery of quad-play services. Customers expect their services (Voice, Web, IPTV, and P2P) to be unified and fully integrated: single alias contact info and unified services accessible through heterogeneous wireless and wire line networks through all types of terminals with heterogeneous capabilities in an efficient and easy way to use. This sort of experience will be feasible across heterogeneous terminals for different type of end-users (nomadic, home-user). In addition to unified service delivery, the paper studies the current and future solutions to user-centric provisioning of a unified service security framework for quad-play services. In contrast to traditional PSTN technologies, the provisioning of services over All-IP based infrastructures (e.g. Web, VoIP, IPTV, and P2P) is based on the concept of separation between the signalling and media infrastructure. Thereby the signalling infrastructure is mainly needed for establishing the communication sessions between the users and does not have to deal with media transport. Moreover, the distributed architecture nature separate subsystems providing end-to-end connectivity from the application. Possible flaws and vulnerabilities in terms of protocols, functionalities and implementation of a service (e.g. VoIP, Web, and P2P) may lead to a DoS of another (e.g. IPTV). The rest of the paper is organized as follows. Section II includes an overview of the vision of future networks and their evolution. In Section III the role of IMS in evolution of services and service delivery is analysed. Furthermore, extended functionalities of IMS are also discussed. An overview of the methods and tools that are used for the building and testing of IMS platforms is presented in Section IV and in Section V a testing scenario of unified quad-play service delivery is proposed. The paper concludes in Section VI with a brief discussion over the most important issues presented in the paper.