Nowadays mobile telecommunication networks are evolving rapidly. The 4th generation LTE (Long Term Evolution) networks has spread significantly. Thanks to the IMS (IP Multimedia Subsystem) the convergence of services has accelerated. The IMS makes any communication possible regardless of access technology (2G, 3G, 4G mobile networks, WiFi, IP networks). By now Voice over LTE/WiFi based telephony is widely available.
Possibilities of the IMS service extension are basically unlimited thanks to the application servers. With the help of TAS (Telecommunication Application Server) phone calls can be established and it also makes several extension services available. The TAS has many interfaces, including the Ut. With this interface, using the HTTP/XCAP (XML Configuration Access Protocol) protocol the users can interrogate and modify supplementary services (for example: voicemail, caller line identification, call forwarding, etc.). The service data is stored in the simserv.xml document which is standardized by 3GPP and is located in HSS (Home Subscriber Server).
The thesis aims at the development of two new interfaces of the TAS, which enables the operator to handle custom defined XML documents according to specific XSD (XML Schema Definition). This way it is possible for the operator to manage any kind of XML document – through TAS – which is stored in HSS. The interface design should consider scalability, fault-tolerant operation and also redundant service.