Efficient IPTV Services Delivery using SVC Adaptation and Cooperative Prefetching

1. Introduction As the demand for Internet-based applications grows around the world, Internet Protocol Television (IPTV) has been becoming very popular. Mobile IPTV allows the users to receive multimedia contents over mobile IP networks using unicast, multicast or peer-to-peer (P2P) communications whenever they want and wherever they are. Common Mobile IPTV services include Live TV and Video-on-Demand (VoD) streaming. The delivery of such services requires addressing the following two issues related to user Quality of Experience (QoE): (1) ensuring minimum start-up delay during channel switching for Live TV, and (2) guaranteeing minimum delay for seek operations in VoD streaming. Solving the above-mentioned issues is crucial for the successful deployment of mobile IPTV services. In Live TV, users perform frequent channel switching to discover interesting programs. Similarly, in VoD streaming, the freedom of choosing content leads to a large number of seek operations [1]. In both cases, delay reduction is more important than providing the full quality of the video. In the other hand, to support clients with diverse capabilities and requirements, the MPEG is defining a scalable extension of H.264 AVC namely Scalable Video Coding (SVC) that is able to simultaneously support multiple spatial, temporal and SNR resolutions with minimum processing and transmission overhead [2]. The SVC is being attracting great interests in the research community. An SVC video stream is a collection of atomic data units namely NALU (Network Abstraction Layer Unit). It consists of a single base layer and one or multiple enhancement layers. The base layer is the most important layer and is essential for decoding the other layers while the exclusion of some or all of the enhancement layers still allows a reasonable quality. The adoption of SVC in streaming services faces two key design challenges: (1) layer selection: how many layers each user should receive; and