IMS

The 3GPP IP Multimedia Subsystem, one of the things I've been involved for a couple of years now (so it isn't against my Disclaimer to say so).

Specs I have a passing interest in:

• 3GPP:23.207 - End-to-end Quality of Service (QoS) concept and architecture
• 3GPP:29.209 - Policy control over Gq interface
• 3GPP:33.210 - IP Network Layer Security