Quality of Service Provisioning in the IP Multimedia Subsystem

The 3GPP IMS defines a network architecture that allows rapid provisioning of rich multimedia services. While standardization of the IMS core architecture is largely complete, there are several areas that are still to be addressed before effective deployment can be realized. In particular a QoS framework is required that efficiently manages scarce network resources, ensures reliability and differentiates IMS services from web-based services. This chapter reviews the most promising candidate resource management frameworks, performs architectural alignment and defines a set of generic terms and elements to provide a convenient point of departure for future research. This harmonization of standardized architectures is critical to avoid interoperability concerns that could cripple deployment. Further challenges are discussed, in particular the vertical and horizontal co-ordination of resources, and current research works that address these challenges are presented.