Mobile device, location estimation method, and computer-readable recording medium

1. A mobile device comprising:

a processor configured to execute a process including:

transmitting a radio wave intensity state to a first base station device having strongest radio wave intensity among a plurality of base station devices present at a location communicable with the mobile device, the radio wave intensity state including, for each of the plurality of base station devices, identifier of the base station device, radio wave intensity which is measured between the mobile device and the base station device and location information indicating a location of the mobile device which measures the radio wave intensity;

acquiring, from the first base station device, a first radio wave intensity state which the first base station device receives and stores from the mobile device and other mobile devices;

by referring to the acquired first radio wave intensity state, first estimating a center of a circle as the location of the first base station device, the circle passing through each location of mobile devices having an identifier of the first base station device;

by referring to the acquired first radio wave intensity state, second estimating, for each of neighboring base station devices in the vicinity of the first base station device, a center of a circle as the location of the neighboring base station device, the circle passing through each of the location of mobile devices having the identifier of a neighboring base station device;

generating a circle in which a distance between the mobile device and the first base station device estimated by using the radio wave intensity is set as a radius and in which the estimated location of the first base station device is set as a center;

generating, for each of the neighboring base station devices, a circle in which a distance between the mobile device and the neighboring base station device estimated by using the radio wave intensity is set as a radius and in which the estimated location of the neighboring base station device is set as a center; and

third estimating a location of the mobile device by using an algorithm selected based on the number of the generated circles and a location relation between the generated circles.

2. The mobile device according to claim 1 , wherein when a plurality of circles generated intersect at a point, the third estimating includes estimating that the point is the location of the mobile device.

3. The mobile device according to claim 1 , wherein when a plurality of circles corresponding to each of the first base station devices and two of the neighboring base station devices intersect with each other at two points, the third estimating includes estimating that an intersection point of a line segment joining a plurality of intersection points of the circles is the location of the mobile device.

4. The mobile device according to claim 1 , wherein when an angle of each vertex of a triangle, in which a vertex is the location of the first base station device and the location of two of the neighboring base station devices, is an acute angle, the third estimating includes estimating that a midpoint of a line segment joining a centroid of the triangle and a vertex corresponding to a location of a base station device having strongest radio wave intensity is the location of the mobile device.

5. The mobile device according to claim 1 , wherein when an angle of any vertex of a triangle, in which a vertex is the location of the first base station device and the location of two of the neighboring base station devices, is an obtuse angle, the third estimating includes estimating that a centroid of the triangle is the location of the mobile device.

6. The mobile device according to claim 1 , wherein when a plurality of circles corresponding to each of the location of the first base station device and the location of the neighboring base station device intersect with each other at two points, the third estimating includes estimating that an intersection point between a line segment joining a plurality of intersection points of the circles and a line segment joining a center of each of the circles is the location of the mobile device.

7. The mobile device according to claim 1 , wherein when a plurality of circles corresponding to each of the location of the first base station device and the location of the neighboring base station devices do not intersect, the second estimating includes extracting a plurality of intersection points between a line segment joining a center of each of the circles and each of the circles, and estimating that a point obtained by dividing a line segment joining each of the intersection points by a radius ratio of the circles is the location of the mobile device.

8. A location estimation method comprising:

transmitting a radio wave intensity state to a first base station device having strongest radio wave intensity among a plurality of base station devices present at a location communicable with the mobile device, the radio wave intensity state including, for each of the plurality of base station devices, identifier of the base station device, radio wave intensity which is measured between the mobile device and the base station device and location information indicating a location of the mobile device which measures the radio wave intensity, using a processor;

acquiring, from the first base station device, a first radio wave intensity state which the first base station device receives and stores from the mobile device and other mobile devices, using the processor;

by referring to the acquired first radio wave intensity state, estimating a center of a circle as the location of the first base station device, the circle passing through each location of mobile devices having an identifier of the first base station device, using the processor;

by referring to the acquired first radio wave intensity state, estimating, for each of neighboring base station devices in the vicinity of the first base station device, a center of a circle as the location of the neighboring base station device, the circle passing through each of the location of mobile devices having the identifier of a neighboring base station device, using the processor;

generating a circle in which a distance between the mobile device and the first base station device estimated by using the radio wave intensity is set as a radius and in which the estimated location of the first base station device is set as a center, using the processor;

generating, for each of the neighboring base station devices, a circle in which a distance between the mobile device and the neighboring base station device estimated by using the radio wave intensity is set as a radius and in which the estimated location of the neighboring base station device is set as a center, using the processor; and

estimating a location of the mobile device by using an algorithm selected based on the number of the generated circles and a location relation between the generated circles, using the processor.

9. A non-transitory computer-readable recording medium having stored therein a location estimation program that causes a mobile device to execute a process comprising:

transmitting a radio wave intensity state to a first base station device having strongest radio wave intensity among a plurality of base station devices present at a location communicable with the mobile device, the radio wave intensity state including, for each of the plurality of base station devices, identifier of the base station device, radio wave intensity which is measured between the mobile device and the base station device and location information indicating a location of the mobile device which measures the radio wave intensity;

acquiring, from the first base station device, a first radio wave intensity state which the first base station device receives and stores from the mobile device and other mobile devices;

by referring to the acquired first radio wave intensity state, estimating a center of a circle as the location of the first base station device, the circle passing through each location of mobile devices having an identifier of the first base station device;

by referring to the acquired first radio wave intensity state, estimating, for each of neighboring base station devices in the vicinity of the first base station device, a center of a circle as the location of the neighboring base station device, the circle passing through each of the location of mobile devices having the identifier of a neighboring base station device;

generating a circle in which a distance between the mobile device and the first base station device estimated by using the radio wave intensity is set as a radius and in which the estimated location of the first base station device is set as a center;

generating, for each of the neighboring base station devices, a circle in which a distance between the mobile device and the neighboring base station device estimated by using the radio wave intensity is set as a radius and in which the estimated location of the neighboring base station device is set as a center; and

estimating a location of the mobile device by using an algorithm selected based on the number of the generated circles and a location relation between the generated circles, using the processor.