Multimedia adaptation with SIP resource availability signalling in IMS-networks

Unlicensed, nondedicated and nondeterministic computer access networks are included in IP multimedia subsystem (IMS) in addition to the operator core network, which arises new end-to-end quality-of-service (QoS) issues for multimedia streaming. The resource availability of the network and the end-devices change drastically during a single multimedia session, which may cause a significant degradation in the overall user experience. In this paper, a multimedia content and quality adaptation framework depending on resource availability signalling over session initiation protocol (SIP) is proposed as a solution to this problem. Availability of network resources (e.g. bandwidth, buffer space) and end-device resources (e.g. battery, CPU, memory, storage) during a session is monitored and signalled over the network in real-time by the resource managers residing at both ends of the session. This framework is compliant with the IMS standard and is implemented as a plug-in.