SERVER DEVICE, MOBILE TERMINAL AND POSITIONING MODE SELECTING METHOD

• US 20070279281A1
• Filed: 05/31/2007
• Published: 12/06/2007
• Est. Priority Date: 05/31/2006
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Shen, Jiyun, Yamada, Takefumi, ODA, Yasuhiro
• Granted Patent: US 7,663,540 B2
• Time in Patent Office: Days
• US Class Current: 342/357.430
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 19/48 by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system
• CPC Class Codes: G01S 5/0018 Transmission from mobile station to base station
• CPC Class Codes: G01S 5/0045 Transmission from base station to mobile station G01S5/009 takes precedence
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A calculation server estimates a position of a mobile terminal that communicates with a base station incorporated with received global positioning system satellite signals. The calculation server includes a positioning information analyzer configured to select one of the positioning modes to be used out of a cell/sector positioning mode and a hybrid positioning mode on the basis of a distance between a cellular base station and the mobile terminal, and a position detector configured to calculate the position of the mobile terminal in the positioning mode selected by the positioning information analyzer.

Claims

1. A server device configured to receive a signal from a global positioning system satellite and to estimate a position of a mobile terminal for communicating with a base station, comprising:

a positioning information analyzer configured to select one of the positioning modes to be used out of a cell/sector positioning mode and a hybrid positioning mode on the basis of a distance between the base station and the mobile terminal; and

a position detector configured to calculate the position of the mobile terminal in the positioning mode selected by the positioning information analyzer.

2. The server device according to claim 1, wherein the distance is determined based on round trip time between the base station and the mobile terminal.

3. The server device according to any one of claims 1 and 2, wherein the positioning information analyzer calculates a predetermined threshold on the basis of an estimation error in the cell/sector positioning mode and of an estimation error in the hybrid positioning mode, compares the distance with the predetermined threshold, and selects the cell/sector positioning mode when the distance is smaller than the predetermined threshold.

4. A mobile terminal configured to receive a signal from a global positioning system satellite and to communicate with a base station, comprising:

a positioning information analyzer configured to select one of the positioning modes to be used out of a cell/sector positioning mode and a hybrid positioning mode on the basis of a distance between the base station and the mobile terminal; and

a position detector configured to calculate the position of the mobile terminal in the positioning mode selected by the positioning information analyzer.

5. A positioning mode selecting method for selecting a positioning mode to be used that is used for estimating a position of a mobile terminal configured to receive a signal from a GPS satellite and to communicate with a base station, the method comprising the steps of:

selecting one of the positioning modes to be used out of a cell/sector positioning mode and a hybrid positioning mode on the basis of a distance between the base station and the mobile terminal; and

calculating the position of the mobile terminal in the positioning mode selected by the positioning mode.