US Patent 7764950 Advanced voice services architecture framework

Advanced voice services, such as 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), are provided for wireless networks. These services are provided by an architectural framework that interfaces into the wireless network in order to provide group call setup and messaging. Handset pre-provisioning reduces customer interaction in the process of activating handsets for use in the network. Presence messages are communicated between handsets and a real-time exchange using the Short Message Service (SMS), but without having to transmit the messages through a Short Message Service Center (SMSC) gateway, but instead the messages are transmitted using Mobile Application Part (MAP) interface connecting the real-time exchange directly to a mobile switching center.