An IMS-based manageable P2P live streaming system in NGN

In the IMS-based NGN service platform, live streaming is an important value-added service. But the distribution of streaming media is a difficult problem because of its massive bandwidth requirement and real-time requirement. Since IP multicast needs to update the whole network routers, this paper introduces P2P technology into live streaming system, which leverages the IP-based policy control and session-based QoS reservation mechanism of IMS. In the service system, the P2P cluster is constructed and managed in the central server deployed at the service plane without any modification to the standard IMS architecture. Several functional entities such as OMF, NRQF and P2P-enabled UE are extended based on the IMS-based IPTV architecture defined by ETSI TIAPAN. When the P2P-enabled UE initiates the service request, SCF as a SIP B2B UA is responsible for the session establishment among neighboring peers relying on the peer selected result from OMF. According to peer grouping judgment returned from NRQF, the OMF groups the UEs watching the same live channel into different peer clusters. Furthermore, this paper describes the session flows and QoS reserving procedure in the detail, and emphasizes the manageability of the P2P overlay.