Patent ID: 8452291

Claim:
A wireless handheld telephony device comprising at least one wireless signal receiver, at least one wireless signal transmitter, and at least one data processor configured to send and receive wireless signals representing control messages to and from a call control server during an ongoing communication session between the wireless handheld telephony device and a second telephony device, by: when an in-band path for communication of the wireless signals representing control messages has been established between the wireless handheld telephony device and the call control server for the ongoing communication session, in response to a determination that an out-of-band path to the call control server has become available: sending the wireless signals representing control messages through the at least one wireless signal transmitter to the call control server using the out-of-band path; and receiving the wireless signals representing control messages through the at least one wireless signal receiver from the call control server using the out-of-band path; when the out-of-band path for communication of the wireless signals representing control messages has been established between the wireless handheld telephony device and the call control server for the ongoing communication session, in response to a determination that the out-of-band path to the call control server has become unavailable: initiating in-band communication with the call control server using the in-band path; sending the wireless signals representing control messages through the at least one wireless signal transmitter to the call control server using the in-band path; and receiving the wireless signals representing control messages through the at least one wireless signal receiver from the call control server using the in-band path.