Rui CarmoThe 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