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.