Extending IMS specifications based on the charging needs of IPTV

Abstract: With the standardization of IP Multimedia Subsystem (IMS), the telecommunications scene becomes more and more converged and in the future we will most likely access our services from all kinds of devices and link them together. One important future access method that has so far been left out of the standardization is television. There is a need for Internet Protocol Television (IPTV) to work together with IMS and this thesis focuses on one aspect of that convergence, namely charging. The problem explored in this thesis is if there is an efficient way of charging for IPTV services while taking advantage of the IMS charging functionality and this is done for two aspects of the problem. First, the possiblilty of an efficient Session Initiation Protocol (SIP) signaling schema is investigated and then a good charging Application Programming Interface (API) to be used when developing applications is investigated. The findings of these two investigations are then tested and improved during the implementation of a demo application. This thesis delivers specifications for a signaling schema that enables a Set-Top Box (STB) to pass charging information to an IMS network via INFO requests inside a special charging session. The schema is small and extendable to ensure that it can be modified further on if necessary. The thesis also delivers an encapsulating and intuitive charging API to be used by developers who want to charge for their services.