How to deploy, provision, and store initial filter criteria in an IMS network

In 3GPP IMS networks, trigger points are used to delegate service execution to dedicated application servers. Trigger points are the main components of initial Filter Criteria (iFC) that are stored on the central IMS subscriber database, the HSS, and dynamically downloaded to the users’ call control proxies at registration time. The XML format for iFC download is standardized, whereas the storage format is not. We propose a novel storage format that decomposes trigger points into user independent, global data and user specific data. The former part is stored in a global trigger point template dictionary, the latter part on a per user basis. Our approach reduces storage consumption by 50%, compared with regular XML compression. The access und conversion time is virtually the same as access to an iFC in plain XML representation; in same cases our approach even outperforms plain XML access. Finally, the trigger point template approach simplifies the potentially complex process of service deployment and provisioning.