Date Added: Jul 2010
IMS charging can be performed at various planes of the IMS architecture. Different charging schemes may be utilized. The optimal charging scheme would be service dependent, but may also be influenced by user expectations. The 3GPP has standardized charging mechanisms, protocols and interfaces for IMS charging control; online and offline charging have been standardized. However, the design and development of charging systems is operator dependent. This paper presents an IMS charging prototype developed and implemented in C, in line with Open IMS research.