IPv6 over DVB-T: Mobility Issues and Challenges Ψ Daniel NEGRU 1 , Yassine HADJADJ-AOUL 1 , Ahmed MEHAOUA 1 , Anastasios KOURTIS 2 1 CNRS-PRiSM Lab., University of Versailles 45, av. des Etats Unis 78035 Versailles - France {dan, yana, mea}@prism.uvsq.fr 2 Institute of Informatics and Telecommunications NCSR «DEMOKRITOS», Agia Paraskevi Attikis, 15310 Athens - Greece kourtis@iit.demokritos.gr ABSTRACT Next generation networks will consist of the interoperation of digital video broadcasting and Internet protocols. Internet protocols standards are IPv4 and IPv6 and concerning broadcasting, DVB is expected to be the leading technology. As a matter of fact, integrating Internet over DVB is not a simple task, due to the many differences of those two in the way of handling particular domains, such as multicasting, mobility, and quality of service. Also, there exist several kinds of DVB technologies, DVB-S for Satellite, DVB-C for Cable, DVB-T for terrestrial, each one with its own specifications. This paper focuses on the mobility aspects of IPv6 over DVB-T mechanisms; it presents the mobility issues and challenges arising from the integration of next generation Internet, IPv6, over the coming terrestrial digital television standard, DVB-T. It presents mobility scenarios in a special DVB-T environment, along with a complete broadcasting architecture, in which all leading mobile technologies coexist, and provides solutions and enhancements for a better technology interoperation. This work has been accomplished within the context of the IST-funded European project ATHENA. KEYWORDS: IPv6, DVB-T, Mobility 1 INTRODUCTION Interoperation of digital video broadcasting standards and Internet protocols based services represents one main evolution in next generation of new services for digital television. Services range from normal web surfing to many other multimedia applications, like video streaming, distant learning, videoconference and TV-specific services. Concerning broadcasting standards, Digital Video Broadcasting (DVB) [3] is expected to be prominent television broadcast standard for next decades, as well through a satellite-based technology (DVB-S), as in terrestrial television (DVB-T), or cable (DVB-C). The evolution in satellite digital broadcast has lead to wide variety of Internet and multimedia applications, even in the few first years of service launch. Even though being member of the same protocol family, terrestrial digital television standard (DVB-T) [4] sets quite different constraints on performance than satellite digital television (DVB-S). Internet protocols standards are IPv4 and IPv6, respectively the former and next generation of prominent networks protocols. IPv6 [1], with its enormous number of addresses and other new features, is undoubtedly the most adequate to multimedia applications. Therefore, integration of DVB and IPv6 seems to be an interesting objective to conceive for next generation services of digital television. Furthermore, the growth in wireless networks predicts an increasing role of wireless communication techniques in the future and consequently, mobility is taking an important role in next generation services. DVB-T provides a relatively high bandwidth data channel but it is only unidirectional. Mobile multimedia terminals require also a return channel through different techniques, such as WLAN or UMTS. Future evolution on portability and mobility has also effects on use and performance of Internet protocols. Mobile IP in IPv4, but especially in IPv6, offers solution to handle mobility at a network protocol layer. In this article, we present the mobility issues and challenges of the integration of the new version of the Internet, IPv6, and the terrestrial television broadcasting standard, DVB-T. A complete architecture is presented, for which any mobility scenario is depicted, from vertical handovers to horizontal ones, from one designed technology to another, featuring WLAN and UMTS. New mobile solutions are developed and enhancements are suggested in order to optimize such mechanisms. Also, the European project ATHENA through which the validation and integration of this approach will be achieved is outlined. Ψ This work has been partially performed within the context of the European research project IST ATHENA (http://www.athena.org ). The authors would like to thank the participants for their contributions. P3/1