1. 3GPP TS 22.071, Technical Specification Group Services and System Aspects; Location Services (LCS); Service description; Stage 1, version 7.1.0, 2005-01.
2. 3GPP TS 22.141: Presence Service, Stage 1.
3. 3GPP TS 23.125: Overall high level functionality and architecture impacts of flow based charging; Stage 2.
4. 3GPP TS 23.167: Internet Protocol (IP) based IP Multimedia Subsystem (IMS) emergency sessions; Stage 2.
5. 3GPP TS 23.228: IP Multimedia Subsystem (IMS); Stage 2.