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...http://www.google.fr/patents/US7826603?utm_source=gb-gplus-shareBrevet US7826603 - Push-to-talk wireless telecommunications system utilizing a voice-over-IP network
Push-to-talk wireless telecommunications system utilizing a voice-over-IP ...
