Session and media signaling for IPTV via IMS
As the IMS provides session establishment, QoS parameter negotiation, authentication and accounting it is an overlay architecture well qualified for session signaling concerning IPTV scenarios. The management of the signaling can be integrated as an application into an IPTV Application Server. The IPTV AS is further responsible for all necessary media signaling towards a proper IPTV media server. Such a media server is similar to the ordinary media server known from the voice centric IMS but additionally provides uni-cast, multicast and broadcast delivery of TV content which is placed by content providers. The media signaling requires a dedicated session description and can be provided by SIP or RTSP. The signaling between user and media server is orchestrated by a service-oriented-archietctue with a session manager acting as middleware. This middleware also provides interfaces for web services triggering IPTV session establishment via Parlay X gateway. This paper proposes a general IMS-based framework for delivering Live TV services over several access networks and presents the corresponding signaling flows for content enquiring and content switching as well as related delays. It furter presents an approach for using SIP and RTSP in cooperation for realizing VOD scenarios.