Apparatus and method for detecting a location of a mobile station in a mobile communication system

Patent metadata

Field	Value
Publication number	US-9282528-B2
Application number	US-201313775498-A
Country	US
Kind code	B2
Filing date	Feb 25, 2013
Priority date	Mar 30, 2012
Publication date	Mar 8, 2016
Grant date	Mar 8, 2016

Abstract

In a mobile communication system, a mobile-station location information management device creates plural transmission-power output data-sets including individual pieces of transmission-power data of plural base-stations with changing the transmission-power of the plural base-stations; creates plural reception-power data-tables individually corresponding to the created plural transmission-power output data-sets and each including plural pieces of divided-area data individually corresponding to plural individual divided-areas within a location-detection target area where each piece of divided-area data includes reception-power data of signals transmitted from the plural base-stations; selects a reception-power data table corresponding to the changed transmission-power data-set from among the created plural reception-power data-tables when the transmission-power of the plural base-stations are changed after the mobile-station has moved into the location-detection target area; and detects, as a location of the mobile-station, an area indicated by divided-area data where a difference from a reception-power data-set received from the mobile-station is slight, within the selected reception-power data-table.

First claim

What is claimed is:

1. A mobile station location detection method performed in a mobile communication system where a base station management device changes transmission power of plural base stations in response to a communication state of a wireless network between a mobile station and the plural base stations, the mobile station location detection method comprising:
creating, by a mobile station location information management device included in the mobile communication system, a plurality of transmission power output data sets, each data set including individual pieces of transmission power data of the transmission power of the plural base stations by changing the transmission power of the plural base stations;
creating, by the mobile station location information management device, a plurality of reception power data tables configured to individually correspond to the created plurality of transmission power output data sets wherein each of the plurality of reception power data tables includes plural pieces of divided area data, each of which includes reception power data of signals transmitted from the plural base stations, the plural pieces of divided area data individually corresponding to a plurality of individual divided areas within a location detection target area where communication is covered by the plural base stations;
receiving, by the mobile station location information management device, a changed transmission power data set including individual pieces of changed transmission power data of the plural base stations from the base station management device and selecting a reception power data table corresponding to the received changed transmission power data set, from among the plurality of created reception power data tables, when the base station management device changes the transmission power of the plural base stations after the mobile station has moved into the location detection target area;
upon receiving a request for providing location information of the mobile station from an external device, instructing, by the mobile station location information management device, the mobile station to measure, in a location where the mobile station exists, pieces of reception power data of individual signals that are transmitted from the plural base stations at the changed transmission power; and
receiving, by the mobile station location information management device, a reception power data set including the individual pieces of reception power data measured by the mobile station, detecting, as a specific location where the mobile station exists, a specific area indicated by divided area data where a difference with respect to the received reception power data set is minimum, within the selected reception power data table, and transmitting information indicating the detected specific location to the external device.

2. The mobile station location detection method according to claim 1 , further comprising:
creating, by the mobile station location information management device, a reception power data table corresponding to the changed transmission power data set using the created plurality of reception power data tables when no transmission power data set coinciding with the changed transmission power data set exists within the created plurality of transmission power output data sets.

3. The mobile station location detection method according to claim 2 , further comprising:
selecting, by the mobile station location management device, two transmission power data sets included in the created plurality of transmission power data sets wherein the individual pieces of the changed transmission power data of the plural base stations have values intermediate between individual pieces of transmission power data included in the two transmission power data sets and values of the two transmission power data sets are most closely related to the changed transmission power data set; and
creating, by the mobile station location management device, a reception power data table corresponding to the changed transmission power data set, by performing weighted averaging on reception power data included in divided area data between reception power tables individually corresponding to the two selected transmission power data sets.

4. A mobile station location detection method performed in a mobile communication system where a base station management device changes transmission power of plural base stations in response to a communication state of a wireless network between a mobile station and the plural base stations, the mobile station location detection method comprising:
creating, by a mobile station location information management device included in the mobile communication system, a plurality of transmission power output data sets each including individual pieces of transmission power data of the plural base stations with changing the transmission power of the plural base stations;
creating, by the mobile station location information management device, a plurality of reception power data tables configured to individually correspond to the created plurality of transmission power output data sets wherein each of the plurality of reception power data tables includes plural pieces of divided area data, each of which includes reception power data of signals transmitted from the plural base stations, the plural pieces of divided area data individually corresponding to a plurality of individual divided areas within a location detection target area where communication is covered by the plural base stations;
receiving, by the mobile station location information management device, a changed transmission power data set including individual pieces of changed transmission power data of the plural base stations from the base station management device and selecting a reception power data table corresponding to the received changed transmission power data set, from among the plurality of created reception power data tables, when the base station management device changes the transmission power of the plural base stations after the mobile station has moved into the location detection target area;
upon receiving a request for providing location information of the mobile station from an external device, instructing, by the mobile station location information management device, the mobile station to measure, in a location where the mobile station exists, pieces of reception power data of individual signals that are transmitted from the plural base stations at the changed transmission power;
receiving, by the mobile station location information management device, a reception power data set including the individual pieces of reception power data measured by the mobile station, detecting, as a specific location where the mobile station exists, a specific area indicated by divided area data where a difference with respect to the received reception power data set is minimum, within the selected reception power data table, and transmitting information indicating the detected specific location to the external device;
creating, by the mobile station location information management device, a reception power data table corresponding to the changed transmission power data set using the created plurality of reception power data tables when no transmission power data set coinciding with the changed transmission power data set exists within the created plurality of transmission power output data sets;
selecting, by the mobile station location management device, two transmission power data sets included in the created plurality of transmission power data sets wherein individual pieces of transmission power data included in the two transmission power data sets have values smaller than the individual pieces of the changed transmission power data of the plural base stations and the two tran

Assignees

• Fujitsu Ltd

Inventors

• Hashimoto Masanori

Classifications

• G01S5/02524

  Creating or updating the radio-map · CPC title

• H04W64/00 Primary

  Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management · CPC title

• G01S5/0252

  Radio frequency fingerprinting · CPC title