A Subscriber Identity Module (SIM) that stores the logic and data for
providing advanced voice services (AVS) including Push-to-Talk (P2T),
Push-to-Conference (P2C), Upgrade to Conference (upgrade from P2T to
P2C), Push-to-Message (P2M) and group SMS (Short Message Service), on
wireless handsets and networks. When inserted into a handset, the AVS
functionality is available for use on the handset, wherein the
functionality includes menu displays for the handset, as well as user
interaction with the menu displays. The SIM also stores logic and data
for providing presence and availability functions on the handset. In
addition, the SIM stores the logic and data for providing contact and
group management on the handset.