Apple Inc.

Nortel Networks Corporation

Barbara Derryberry

Robert E Denman

Sriram K Parameswar

A method and system to provide ad-hoc push-to-talk calls between a plurality of users in a wireless packet data telecommunications network are described. The system may include: a wireless communication network including push-to-talk (PTT) functionality, with a Session Initiation Protocol (SIP) Proxy Server; a SIP Registrar and Location Server operable to store contact addresses of active mobile devices; a Realtime Transport Protocol (RTP) Media Gateway (PTT Server) operable to function as a call endpoint for each of a plurality of mobile devices wherein the plurality of mobile devices may be segmented into membership groups, the PTT Server further operable to multicast a communication from one member of the group to the other members of the group; and an Internet Protocol (IP) network interconnecting the SIP Proxy server, the SIP Registrar and Location Server, and the PTT Server.

Push-to-talk telecommunications system utilizing an voice-over-IP network

A method and system to provide push-to-talk from one user to another in a wireless packet data telecommunications network is described. The system may include: a wireless communication network including push-to-talk (PTT) functionality, with a Session Initiation Protocol (SIP) Proxy Server; a SIP Registrar and Location Server operable to store contact addresses of active mobile devices; a Realtime Transport Protocol (RTP) Media Gateway (PTT Server) operable to function as a call endpoint for each of a plurality of mobile devices wherein the plurality of mobile devices are segmented into membership groups, the PTT Server further operable to multicast a communication from one member of the group to the other members of the group; and an Internet Protocol (IP) network interconnecting the SIP Proxy server, the SIP Registrar and Location Server, and the PTT Server.

Push-to-talk telecommunications system utilizing a voice-over-IP network

System and method for enabling push-to-talk (PTT) private calls in a wireless communications network are described. One embodiment includes selecting a called party private identification for a private call by a calling party on a mobile device; pressing a PTT button on the mobile device; transmitting a SIP SUBSCRIBE including the calling and called parties private identifications to request a speech token; redirecting the SIP SUBSCRIBE to the PTT Server for purposes of removing the calling party and the called party from a multicast group; receiving an acknowledge message that includes a speech token; transmitting calling party information from the PTT Server to the called party; communicating speech packets from the calling party to the called party in a half-duplex manner; releasing the PTT button on the mobile device; transmitting a SIP SUBSCRIBE to release the speech token; and notifying the calling and called parties that the group's speech token is available.

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Plano, TX, United States of America

Barbara Derryberry