Design and implementation of scalable IMS charging systems

Billing, charging and accounting are the most critical operational support activities for any telecommunications network operator. Through these activities operators recover costs for service provision, and make business profits. IMS charging is required at the services level as well as the transport level. In networks with QoS guarantees, it is necessary for user preferences of service quality levels be accommodated. This is critical when the cost of service has a strong relation to the service quality. There is a need to minimize resource utilization and costs related to charging and billing. Customized, efficient and user friendly service provision systems will enable the network operator to remain competitive. In this paper we explore the design of a user friendly efficient charging, billing and accounting system for 3GPP based IMS networks. We implement the system in a real IMS prototype, and perform a series of tests to determine the best charging schemes to apply for popular IMS services. User interaction with the system is achieved through interfaces created on the user agent.