A wireless subscriber terminal (ST) for use with IP push-to-talk (IPP2T) service using a wireless local area network (WLAN) operating in a plurality of modes, including a mobile terminal having an ability to communicate over the air to a wireless Access Point (AP), the mobile terminal further programmable...http://www.google.com/patents/US7738407?utm_source=gb-gplus-sharePatent US7738407 - Method and apparatus for delivering IPP2T (IP-push-to-talk) wireless LAN mobile radio service
