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

• US 7,013,150 B2
• Filed: 09/26/2002
• Issued: 03/14/2006
• Est. Priority Date: 10/03/2001
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Furukawa, Hiroshi, Yamazaki, Shuntaro, Okanoue, Kazuhiro
• Primary Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US10/254,772
• Publication Number:
  US 20030064733A1
• Time in Patent Office: 1,265 Days
• Field of Search: 455/67.16, 455/456.1, 455/456.2, 455/456.3, 455/456.5, 455/456.6, 455/457, 455/404.2, 455/414.2, 701/207, 701/214, 701/216, 340/988, 342/357.1, 342/357.06, 342/357.12, 342/450
• US Class Current: 455/456.1
• 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;

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; and

said positioning server further 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.

2. 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; and

said positioning server further 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.

3. 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:

in each of said base stations 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;

in said positioning server 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; and

in said positioning server further 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.

4. 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;

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;

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; and

said estimating step estimates which of said preset areas said terminal exists in by further evaluating whether or not each of said results of checking meets an existence condition set on initialization.

5. The terminal location estimation method according to claim 4, wherein a difference between said estimation result and said measurement result is used for checking against said existence condition.

6. 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 mobile terminal via radio links and connected to said positioning server via a network, wherein;

each base station of said plurality of base stations has receiving means for receiving a signal transmitted from said mobile terminal, measuring means for measuring both an amplitude and a delay spread of the signal received by said receiving means without using a GPS device, and means for sending the measurement results of said measuring means to said positioning server; and

said positioning server has storing means for storing estimated amplitudes and estimated delay spreads of a signal transmitted from within each preset area of said plurality of preset areas and received at said each base station, and estimating means for estimating the location of said mobile terminal by checking said estimated amplitudes and estimated delay spreads stored in said storing means against said measurement results sent by said each base station;

wherein said positioning server further has estimating means for estimating a radio wave propagation environment between said each preset area and said each base station based on at least the location of said each base station and placement of structures in said service area.

7. 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 mobile terminal via radio links and connected to said positioning server via a network, wherein;

each base station of said plurality of base stations has receiving means for receiving a signal transmitted from said mobile terminal, measuring means for measuring both an amplitude and a delay spread of the signal received by said receiving means without using a GPS device, and means for sending the measurement results of said measuring means to said positioning server; and

said positioning server has storing means for storing estimated amplitudes and estimated delay spreads of a signal transmitted from within each preset area of said plurality of preset areas and received at said each base station, and estimating means for estimating the location of said mobile terminal by checking said estimated amplitudes and estimated delay spreads stored in said storing means against said measurement results sent by said each base station;

wherein said estimating means estimates the location of said mobile terminal by further evaluating whether or not results of said checking meet an existence condition set on initialization.

8. The positioning system according to claim 7, wherein a difference between one of said estimated amplitudes and a corresponding measured amplitude of said measurement results and a difference between one of said estimated delay spreads and a corresponding measured delay spread of said measurement results are used for checking against said existence condition.

9. A terminal location estimation method for estimating a location of a mobile terminal in a service area comprised of a plurality of preset areas, said method comprising steps of:

receiving at each base station of a plurality of base stations a signal transmitted from said mobile terminal;

measuring at said each base station, without utilizing a GPS device, both an amplitude and a delay spread of said received signal;

sending by said each base station the measurement results to a positioning server;

storing at said positioning server estimated amplitudes and estimated delay spreads of a signal transmitted from within each preset area of said plurality of preset areas and received at said each base station;

receiving at said positioning server said measurement results from said each base station; and

estimating at said positioning server the location of said mobile terminal by checking said stored estimated amplitudes and estimated delay spreads against said received measurement results;

wherein said positioning server estimates the location of said mobile terminal by further estimating a radio wave propagation environment between said each preset area and said each base station based on at least the location of said each base station and placement of structures in said service area.

10. A terminal location estimation method for estimating a location of a mobile terminal in a service area comprised of a plurality of preset areas, said method comprising steps of:

receiving at each base station of a plurality of base stations a signal transmitted from said mobile terminal;

measuring at said each base station, without utilizing a GPS device, both an amplitude and a delay spread of said received signal;

sending by said each base station the measurement results to a positioning server;

storing at said positioning server estimated amplitudes and estimated delay spreads of a signal transmitted from within each preset area of said plurality of preset areas and received at said each base station;

receiving at said positioning server said measurement results from said each base station; and

estimating at said positioning server the location of said mobile terminal by checking said stored estimated amplitudes and estimated delay spreads against said received measurement results;

wherein said positioning server estimates the location of said mobile terminal by further evaluating whether or not results of said checking meet an existence condition set on initialization.

11. The terminal location estimation method according to claim 10, wherein a difference between one of said estimated amplitudes and a corresponding measured amplitude of said measurement results and a difference between one of said estimated delay spreads and a corresponding measured delay spread of said measurement results are used for checking against said existence condition.