Patent ID: 8442483

Claim:
A method of conveying location of a wireless communication device (WCD) to an emergency service system comprising a Public Safety Answering Point (PSAP), the WCD including a GPS receiver and a wireless transceiver, the method comprising: the WCD applying the GPS receiver to receive GPS satellite signals, and the WCD using the received signals to determine GPS location coordinates of the WCD; the WCD using dead reckoning as a basis to update the GPS location coordinates in accordance with distance and direction of the WCD inside a building, thereby establishing indoor location coordinates of the WCD; the WCD using the wireless transceiver to transmit the established indoor location coordinates in a signaling message seeking to set up a call to the emergency service system; and at an intermediary in signaling communication with the WCD and the emergency service system, (i) receiving the signaling message, (ii) translating the indoor location coordinates to a building portion descriptor that describes a portion of the building where the indoor location coordinates reside so as to produce a modified signaling message that contains the building portion descriptor, and (iii) sending the modified signaling message along to the emergency service system, wherein the signaling message invokes establishment of a session between the PSAP and the WCD, whereby the building portion descriptor facilitates emergency response.