Abstract: After an introduction of the policy-based quality of service(QoS) mechanisms ofuniversal mobile telecommunication system(UMTS), a new policy-based QoS Framework was proposed for the next generation mobile networks. Enhanced policy management components were defined that cover the radio access networks. Hierarchicalpolicy models with common open policy service(COPS) extensions were introduced to achieve adaptive configuration of network resources and QoS negotiation. A specificcase of this policy-based QoS framework was simulated. The performance resultsshow that the required quality of service of the session can be guaranteed. It also benifits the intelligent configuration and adaptive negotiation of the QoS parameters among networks, and eventually the end-to-end QoS can be well guarenteed in the entire networks.

Key words: :policy-based, quality of service, end to end, IP multimedia subsystem