Patent ID: 8145185
Filing Date: 2012-03-27
Classification: H04L,H04W

Abstract:
1. 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, a compass, a pedometer, 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 the compass and pedometer 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 Session Initiation Protocol (SIP) INVITE message seeking to set up a call to the emergency service system; and at an intermediary in a SIP communication path between the WCD and the emergency service system, (i) receiving the SIP INVITE 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, and (iii) sending the SIP INVITE message, including the building portion descriptor, along to the emergency service system, wherein the SIP INVITE message invokes establishment of a Real-time Transport Protocol (RTP) session between the PSAP and the WCD, whereby the building portion descriptor facilitates emergency response.