Session-based end-to-end policy control in 3GPP evolved packet system
The Third Generation Partnership Project specifies a solution to handle the heterogeneity of future networks, including quality of service (QoS) and charging aspects. This solution utilizes a policy-based approach based on the policy and charging control (PCC) architecture, which is an integral component of the evolved packet system (EPS). The specifications for EPS are being finalized with the evolved packet core (EPC) central to this framework. The EPC is a simplified, flat, all IP-based architecture that supports mobility between heterogeneous access networks and incorporates an evolved QoS concept based on the PCC framework. A critical open issue within EPS is the provisioning of end-to-end QoS enabled paths. This article proposes enhancements to the EPC/PCC framework that extend the end-to-end inter-domain mechanisms to discover the signaling routes at the service control layer, and use this information to determine the paths traversed by the media at the resource control layer. Because the approach operates at these layers, it is compatible with existing transport networks and exploits already existing QoS control mechanisms. A real testbed implementation, comprising free and open source software, is used to evaluate the proposed mechanisms. The obtained results show that the framework has an acceptable effect on session setup delay and core traffic overhead in a range of scenario ranging from simple, to typical, to worst case.