Research And Design Of Policy And Charging Control In IMS

IP Multimedia Subsystem (IMS) is proposed by 3rd Generation Partnership Project based on Release 5 for supporting the IP multimedia services. IMS provides the convergence of IP and mobile communication. It supports access independence and separation of control function and bearer etc. It's important for the policy and charging control in the part of research in IMS. The PDF is located at P-CSCF using for policy control in 3GPP release 5. Subsequently, the PDF is separated from the P-CSCF in the release 6, and converges with the FBC to form the PCC architecture in the release 7. Since the PCC architecture of 3GPP release 7 published, PCC architecture has been widely accepted, and considered to be a feasible policy and charging control architecture. Due to the forefront of 3GPP standards, it's lack of all-sided consideration and an in-depth research for the release 7 PCC architecture implement measure at present, which is a regret for the development of IMS. Therefore, this thesis completed on IMS in policy and charging control theoretical research and design work, has a strong understanding and practical significance of IMS application, and has a strong operability for IMS networks, fixed and mobile convergence and bearer control technologies. The thesis aims to implement the policy and charging control mechanism to support the policy and charging control convergence using the PCRF module in IMS. Firstly this thesis introduces the IMS background, and explains architecture and protocol of IMS. Secondly it researches and describes the evolvement and convergence of charging in IMS, explains the development of policy control and convergence with the FBC. In addition, at the forth chapter, the thesis introduces the PCC architecture,reference point,QoS parameter mapping and policy and charging control at roaming in 3GPP release 7. Researching with the PCC framework, this paper designed the PCRF function models, the class diagram of PCRF function modules, generated PCC Rule flow, which included QoS mapping procedures, bandwidth access information flows, and the bandwidth interacted with QoS flows. By referring the policy and charging control framework in 3GPP release 7 and based on the design of PCRF function module and the PCC Rule generated flows in this paper, the thesis demonstrates the instances using the module and flow to validate the policy and charging control model reasonable.