QOS-DRIVEN MULTIPATH ROUTING FOR ON-DEMAND VIDEO STREAMING IN A PUBLISH-SUBSCRIBE INTERNET Yannis Thomas * , Pantelis A. Frangoudis § , George C. Polyzos * * Department of Informatics, Athens University of Economics and Business, Greece § IRISA/INRIA Rennes-Bretagne Atlantique, France thomasi@aueb.gr, pantelis.frangoudis@inria.fr, polyzos@aueb.gr ABSTRACT Aiming to improve the performance of on-demand video streaming services in an Information-Centric Network, we propose a mechanism for selecting multiple delivery paths, satisfying bandwidth, error rate and number-of-paths con- straints. Our scheme is developed in the context of the Publish-Subscribe Internet architecture and is shown to out- perform state-of-the-art multi-constrained multipath selec- tion mechanisms by up to 7%, and single-path or single- constrained multipath selection schemes by up to 17%, in terms of feasible path discovery, while at the same time im- proving on bandwidth aggregation. Also, it is suitable for sup- porting resource-demanding high-definition scalable video streaming services, offering Quality-of-Experience gains. 1. INTRODUCTION Information-Centric Network (ICN) architectures [1] have emerged as a response to the shift in traditional Internet usage patterns: The host-to-host communication paradigm is being reconsidered in favor of a content-centric one, where the in- terest lies in the information itself, rather than its actual ori- gin. This shift is typically manifested in video services, where content is distributed by means of Content Delivery Networks (CDNs), where the actual host(s) serving the content is of lit- tle importance to its consumers. With video traffic dominating [2] and the demands for HD content anywhere, anytime, and on any device grow- ing [3], more efficient delivery techniques and the necessary network- and application-level support are being called for. At the network level, the exploitation of multiple delivery paths simultaneously is considered, offering bandwidth ag- gregation and resilience advantages. At the application level, advanced encoding techniques, such as Scalable Video Cod- ing (H.264/SVC) [4], often coupled with adaptive streaming, This work has been co-financed by the European Union (European Social Fund-ESF) and Greek national funds through the Operational Pro- gram “Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF) Research Funding Program: Aristeia II/I-CAN, and by the French Ministry of Economy, Industry and Digital Affairs through the Celtic-Plus project QuEEN (Project ID: CP8004) can more efficiently cope with the dynamics of network con- ditions and resource demand. ICN architectures, and the Publish Subscribe Internet (PSI) architecture [5] in particular, in the context of which we position our work, naturally support multipath delivery. In this paper, we make the following contributions: (i) We show where and how this functionality fits in the overall PSI archi- tecture, (ii) propose an algorithm for multiple path selection which caters for multiple performance criteria, showing it to outperform state-of-the-art path selection schemes, and (iii) demonstrate how our multipath scheme can be used by a scal- able video delivery application, quantifying its performance advantages in QoE terms. 2. BACKGROUND 2.1. Publish Subscribe Internet The Publish Subscribe Internet (PSI) is an ICN architecture based on the pub-sub paradigm. Each information item is as- signed a statistically unique identifier for addressing it, re- gardless of its location or owner. Content requests are ad- dressed to the network, contrary to IP’s end-to-end interac- tion, maintaining the loose coupling of pub-sub: A publisher (content provider) issues a publication about an information item and the network stores this information. When a sub- scriber (content consumer) issues a subscription to this con- tent, the network matches it with the prior publication(s), lo- cates it, and undertakes its delivery to the requesting host. This is performed via three clearly separated core functional- ities, i.e., Rendezvous, Topology and Forwarding. Topology functionality involves the discovery of dissem- ination routes between a publisher and multiple subscribers 1 and Forwarding functionality is responsible for content de- livery via source routing. Path discovery is executed by the Topology Manager (TM), a logical entity which receives re- quests from the network’s Rendezvous elements, formulates the appropriate transmission paths and sends them to the end users for direct communication, aiming to satisfy communi- 1 PSI natively operates on multicast, but unicast is also supported.