| 摘要 |
A method and a system for providing location based services by using MS(Mobile Station)-based calls are provided to lower a call processing failure rate in providing location based services using MS-based calls by converting 2222, an SID(System ID) contained in a PPM(Pilot Phase Measurement) message or an SSI(Provide Serving System Information) message, into the actual system ID of an MSC, which an MS uses, using the NID(Network ID), BID(Base Station ID), and reference PN(Pseudo Noise) contained in the PPM or SSI message so that a PDE(Position Determination Entity) or an MPDE(Multi PDE) can offer exact aiding data to the MS. A PDE receives a PPM message from an MS(S500). The PDE checks the received PPM message and confirms whether an MSC, which the MS uses at present, uses a repeated NID(S502). If so, the PDE fetches BS Almanac information, compares the BID and PN contained in the BS Almanac information with the BID and PN contained in the PPM message, and acquires the actual SID of the MSC(S504). Then the PDE changes the SID contained in the PPM message into the acquired actual SID(S508). The PDE creates aiding data, based on the actual SID of the MSC and the NID, BID, and reference PN of the PPM message, and transmits the created aiding data to the MS(S510). |
