| 摘要 |
<P>PROBLEM TO BE SOLVED: To transmit approximate position information of high precision to a communication terminal. <P>SOLUTION: Approximate position information which is used for positioning operation in a communication terminal 60 and indicates a position of a cell C1 visited by the communication terminal 60 and a cell ID identifying the cell C1 are stored in an approximate position information DB23 of an SUPL server 20 in association with each other. The SUPL server 20 acquires approximate position information stored in the approximate position information DB23 on the basis of a positioning information transmission request transmitted from the communication terminal 60 and including the cell ID and transmits the approximate position information to the communication terminal 60 from a communication unit 21. Thereafter, the SUPL server 20 receives positioning result information transmitted from the communication terminal 60 and updates the approximate position information stored in the approximate position information DB23 on the basis of the positioning result information by a control part 22. If positioning operation in the communication terminal 60 fails, the SUPL server 20 determines whether the approximate position information transmitted to the communication terminal 60 is defective or not on the basis of an error code and number-of-satellites information included in the positioning result information from the communication terminal 60 and initializes the approximate position information on the basis of the determination result. <P>COPYRIGHT: (C)2012,JPO&INPIT |
