Patent ID: 8855054

Claim:
A system for establishing two-way calls between a radio one or more two-way push-to-talk radios and a packet-based private branch exchange, comprising: at least one control station operable to exchange messages with said one or more two-way push-to-talk radios over a radio frequency signaling channel and to establish audio communication with said one or more two-way push-to-talk radios over an assigned radio frequency communication channel corresponding to a channel frequency; a gateway operable to: (i) exchange packet communications including signaling messages with said packet-based private branch exchange, (ii) assign at least one communication channel to said one or more two-way push-to-talk radios in response to a call request from the packet-based private branch exchange or one or more of said two-way push-to-talk radios, (iii) convert between analog audio for sending to and receiving from said one or more two-way push-to-talk radios and digital audio packets recognized by said packet-based private branch exchange; and (iv) convert audio tones for activating special features of said packet-based private branch exchange; and said at least one control station being operable to forward a channel assignment message from said gateway to one or more of said two-way push-to-talk radios over said signaling channel to cause said one or more two-way push-to-talk radios to switch to at least one assigned communication channel to establish audio communication with said at least one control station over said at least one assigned communication channel, said at least one control station being further operable to transfer audio including audio tones for activating special features of said packet-based private branch exchange between said one or more two-way push-to-talk radios and said gateway.