Optimisations and Enhancements for Realtime IMS Communication
The scope of the technical report is to capture the results of a study into the optimisations and enhancements of the system for mass market real-time communication (IMS multimedia telephony).
The objective is to provide a study into optimisations and enhancements for the support realtime services based on IMS with regards to the following aspects:
- Analysis of IMS session establishment procedures (e.g. signalling flows, bearer establishment) in order to reduce call establishment time for multimedia telephony to obtain the same, or at least similar, characteristics as exists for CS telephony;
- Analysis of impacts of any non call related IMS signalling (e.g. due to Presence) on the efficiency and service aspects of active real time communication sessions and the establishment of such sessions;
- Analysis into mechanisms to inform the IMS of loss of the signalling bearer transport through the IP-CAN;
- Analysis and identification of architecture and information flow impacts due to the dynamic allocation of users to Application Servers, including analysing any potential impacts at initial registration, session establishment and provision of user data in the HSS;
- Identification of any stage 2 impacts in order to support multimedia telephony services;
- Efficient interworking with other VoIP networks, e.g. regarding call establishment time and simplified call flows.
The study is intended to provide conclusions on the above aspects with respect to future normative specification work.