Positioning system, positioning server, base station and terminal location estimation method

• US 20030064733A1
• Filed: 09/26/2002
• Published: 04/03/2003
• Est. Priority Date: 10/03/2001
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Furukawa, Hiroshi, Yamazaki, Shuntaro, Okanoue, Kazuhiro
• Granted Patent: US 7,013,150 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

To provide a terminal location estimation method capable of accurately estimating a location of a mobile terminal when providing information services according to the location of the terminal in a radio communication system. A positioning server sends a location measurement probe message to the mobile terminal in order to measure the location of the terminal. Each of base stations receives a response message broadcasted from the terminal, measures the reception level and delay spread and sends the measurement results to the positioning server. The positioning server has a radio wave propagation estimating portion and a database for storing estimation results thereof. The server estimates the location of the terminal by checking the measurement results of the base stations against the estimation results on radio wave propagation stored in the database.

Claims

1. A positioning system having:

a positioning server for estimating a location of a mobile terminal in a service area comprised of a plurality of preset areas; and

a plurality of base stations connectable to said terminal via radio links and connected to said positioning server via a network, wherein;

each of said base stations has receiving means for receiving a signal transmitted from said terminal, measuring means for measuring a radio wave propagation environment between said terminal and the base station from the signal received by said receiving means, and means for sending the measurement result of said measuring means to said positioning server; and

said positioning server has storing means for storing a estimation result of the radio wave propagation environment between each of said preset areas and each of said base stations, and estimating means for estimating the location of said terminal by checking said estimation results stored in said storing means against said measurement results from said base stations.

2. The positioning system according to claim 1, wherein said estimation results contain reception levels and impulse responses in said preset areas of radio waves transmitted from said base stations.

3. The positioning system according to claim 1, wherein said estimation results contain reception levels and delay spreads in said preset areas of radio waves transmitted from said base stations.

4. The positioning system according to claim 1, wherein said positioning server has estimating means for estimating the radio wave propagation environment between each of said preset areas and each of said base stations based on at least the location of each of said base stations and placement of structures in said service area.

5. A positioning server connected via a network to a plurality of base stations connectable to a mobile terminal via radio links for estimating a location of said terminal in a service area comprised of a plurality of preset areas, wherein:

said positioning server has storing means for storing a estimation result of a radio wave propagation environment between each of said preset areas and each of said base stations, and estimating means for estimating the location of said terminal by checking said estimation results stored in said storing means against the radio wave propagation environment between said terminal and each of said base stations measured by each of said base stations.

6. The positioning server according to claim 5, having estimating means for estimating the radio wave propagation environment between each of said preset areas and each of said base stations based on at least the location of each of said base stations and placement of structures in said service area.

7. A base station connectable to a mobile terminal via a radio link and connected via a network to a positioning server for estimating a location of said terminal in a service area comprised of a plurality of preset areas, wherein:

said base station has a first radio system comprised of a transmitting and receiving portion for performing communication with said terminal, and a second radio system comprised of a receiving portion for receiving a signal transmitted from said terminal based on information obtained from said positioning server.

8. A terminal location estimation method of a positioning system having a positioning server for estimating a location of a mobile terminal in a service area comprised of a plurality of preset areas, and a plurality of base stations connectable to said terminal via radio links and connected to said positioning server via a network, wherein:

each of said base stations has a step of measuring a radio wave propagation environment between said terminal and the base station based on a received signal from said terminal according to a request from said terminal and sending the measurement result to said positioning server; and

said positioning server has an estimating step of estimating the location of said terminal by checking estimation results stored in storing means for storing the estimation result of the radio wave propagation environment between each of said preset areas and each of said base stations against said measurement results from said base stations.

9. The terminal location estimation method according to claim 8, wherein said estimation results contain reception levels and impulse responses in said preset areas of radio waves transmitted from said base stations.

10. The terminal location estimation method according to claim 8, wherein said estimation results contain reception levels and delay spreads in said preset areas of radio waves transmitted from said base stations.

11. The terminal location estimation method according to claim 8, wherein said positioning server estimates the radio wave propagation environment between each of said preset areas and each of said base stations based on at least the location of each of said base stations and placement of structures in said service area.

12. The terminal location estimation method according to claim 8, wherein said estimating step estimates which of said preset areas said terminal exists in based on results of checking said estimation results against said measurement results.

13. The terminal location estimation method according to claim 12, wherein said estimating step estimates which of said preset areas said terminal exists in by evaluating whether or not each of said results of checking meets an existence condition set on initialization.

14. The terminal location estimation method according to claim 13, wherein a difference between said estimation result and said measurement result is used as said existence condition.