Exploiting Peer-to-Peer technology for network and resource management in interactive broadcasting environments E. Markakis Department of Information and Communication Systems Engineering, University of the Aegean, Samos, Greece emarkakis@aegean.gr E. Pallis Division of Design and Development of Systems and Constructions, Centre for Technological Research of Crete, Heraklion, Greece pallis@pasiphae.eu C. Skianis Department of Information and Communication Systems Engineering, University of the Aegean, Samos, Greece cskianis@aegean.gr V. Zacharopoulos Department of Applied Informatics and Multimedia T.E.I. of Crete, Heraklion, Crete, Greece vzachar@epp.teicrete.gr Abstract— This paper presents a novel DVB/IP infrastructure that exploits P2P technology for optimised resource exploitation in interactive services’ provision. Building upon a prototype DVB-T regenerative platform, it presents a decentralised architecture that exploits the broadcasting stream as part of the core/backbone network, providing interactive IP services to rural/urban citizens. Users access the provided IP services via intermediate communication nodes (access network), which are responsible for managing/controlling both uplink and downlink flows. Towards enhancing the scalability as well as the performance of the entire network, the paper studies the realisation of IP overlays by exploiting P2P technology, and proposes a prototype configuration for optimum resource exploitation and increased Service/Bandwidth gain both at the core and access segments. Performance evaluation experiments carried-out under real transmission/reception conditions verified the validity of the proposed architecture, besides outlining fields for future research. Keywords- DVB-T, P2P, Experiments, Real-Time Transmission I. INTRODUCTION In European Union, the broadcasting standard used to deliver digital services over terrestrial links is the Digital Video Broadcasting-Terrestrial (DVB-T) standard [1]. DVB-T can effectively combine heterogeneous services like digital MPEG- 2 TV programmes and IP services within the same transport stream (TS), thus contributing towards a unified networking environment, where users can access both broadcast and personalised content (interactive broadcasting). However, in order to enable DVB-T platforms as part of networking infrastructures providing not only linear but also interactive IP services, the use of reverse path channels is mandatory. In such a scheme the DVB-T links can be used as downlink trunks in a backbone topology [2] for the interconnection of terrestrial distribution nodes, which may utilize various return path technologies (i.e. PSTN/ISDN, WLAN, ADSL, UMTS, GSM) [3] for the uplink traffic. These distribution nodes act as access networks, providing connectivity/interaction to end users over any existing technology (e.g. WLAN, ADSL). Such an interactive DVB-T implementation has been proposed in [4], where regenerative configurations are exploited for utilizing DVB-T stream as a backhaul 1 network- segment, interconnecting rural distribution nodes, namely Cell Main Nodes (CMN). Experimental evaluation measurements verified that when on-demand services and personalised IP traffic (generated from each distribution node/end-user) contest under the best-effort scheme, the DVB-T downlink is easily overloaded (while uplink and access networks have a negligible utilization), degrading both the system’s scalability and QoS. Although exploitation of DiffServ technology between the regenerative DVB-T platform and each CMN may alleviate these matters [5], optimum system performance still remains an issue, as large part of the overall network resources remain unexploited, especially in the access segment. In contrast, recent research results have indicated that P2P technology [6] has become imperative for applications of content distribution over highly heterogeneous, best-effort network environments. P2P technology exploits efficient bandwidth monitoring and routing decision mechanisms at the application layer applied among nodes at the edges of the network and are tasked of transferring the content to users, 1 Backhaul is a connection from the local “point of presence” (typically a local exchange building) to the mainline or high-capacity backbone networks, which form part of national and international data transmission networks. This connection is a significant issue for accessing broadband services in small cities and/or in rural areas that are away from the national backbone, since high-capacity networks are normally found in large towns, and obtaining connection to them constitutes a challenge with technological/networking and cost parameters. 978-1-4244-5637-6/10/$26.00 ©2010 IEEE This full text paper was peer reviewed at the direction of IEEE Communications Society subject matter experts for publication in the IEEE Globecom 2010 proceedings.