Patent ID: 8228881

Claim:
A system for providing location information of a terminal by using a Session Initiation Protocol (SIP), comprising: a first terminal for transmitting a SIP message for call connection; a second terminal for determining if the SIP message includes a location request when the SIP message for call connection is received from the first terminal, and transmitting a response message including location information of the second terminal when the received SIP message includes the location request; a SIP core for transferring the SIP message for call connection from the first terminal to the second terminal, and transferring the response message from the second terminal to the first terminal; and a location server for performing a positioning procedure together with the second terminal and calculating location information of the second terminal, wherein the second terminal determines if pre-stored location information of the second terminal is present when the received SIP message includes the location request, and transmits the response message including the pre-stored location information of the second terminal when the pre-stored location information of the second terminal is found, wherein the second terminal requests the location server to calculate location information and acquires the calculated location information from the location server when the pre-stored location information of the second terminal is not found.