Patent ID: 7542780

Claim:
A telephone exchange in a telecommunications network, the telephone exchange comprising: means for registering a mobile telephone and assigning a unique extension identifier to the mobile telephone, wherein the mobile telephone is adapted for communication with the telephone exchange via a data channel and a voice channel through a mobile telephony network; communication means for sending call setup signaling messages to the mobile telephone and receiving call setup signaling messages from the mobile telephone over the data channel; means for controlling interfaces associated with the mobile telephone using basic telephony and data communication services of the mobile telephony network exclusive of special mobile operator agreements or special interfaces with the mobile telephony network; means for receiving over the data channel, an indication that the mobile telephone is initiating a call to a called number; and means for performing reverse direction call setup in response to the indication that the mobile telephone is initiating the call to the called number, said means for performing reverse direction call setup including: means for setting up a speech path from the telephone exchange to the called number; means for initiating an outgoing external call in a direction from the telephone exchange to the mobile telephone; means for detecting that the mobile telephone has answered the outgoing external call; and means for connecting the speech path and the outgoing external call to form a speech connection between the mobile telephone and the called number.