Position estimation device, program, and position estimation method

Abstract

Provided is a position estimation device for estimating the position of a mobile communication terminal, the position estimation device comprising: a distance acquisition unit that acquires distance information indicating the distance between a wireless base station and the mobile communication terminal, the distance information being obtained by the wireless base station, which provides mobile communication to the mobile communication terminal, performing radio wave measurement with respect to the mobile communication terminal; a map acquisition unit that acquires map information including information of a structure in a space within a coverage area in which the wireless base station provides mobile communication; and a position estimation unit that estimates the position of the mobile communication terminal in the space within the coverage area on the basis of the distance information and the map information. The position estimation unit may use the information of the structure in the map information within a range specified by the distance centered on the wireless base station and indicated by the distance information, to estimate the position of the mobile communication terminal within the range. The position estimation device may have a RAN control function and an AI processing (for example, RAN Intelligent Controller (RIC)) function.

Description

Position estimation device, program, and position estimation method

[0001] The present invention relates to a position estimation device, a program, and a position estimation method.

[0002] Patent Document 1 describes "a location information calculation device that calculates location information of a mobile communication terminal that can select from a plurality of mobile communication methods, at least a first mobile communication method and a second mobile communication method," and "with such a configuration, location positioning is performed at a plurality of wireless base stations of at least the first mobile communication method and the second mobile communication method, so that location information can be calculated using a larger number of location positioning results." [Prior art documents] [Patent documents] [Patent document 1] JP 2014-216951 A

[0003] In systems that realize connected cars, dynamic information on moving vehicles is collected using GPS information, etc. However, GPS information, etc., belongs to user plane data in mobile communication systems, and due to the system format, wireless base stations and core networks cannot directly grasp GPS information, etc., of the location information of mobile communication terminals under the wireless base station.

[0004] Because the timing and received power of the UL radio frame boundary fluctuate from the perspective of the radio base station, the radio base station applies Timing Advance (TA) and UL power control to the mobile communication terminal to adjust them to constant values. These values ​​are constantly and frequently measured when the radio base station is communicating with the mobile communication terminal. In the location estimation device according to this embodiment, for example, these measurements are combined with additional map information to estimate the traffic volume of the mobile communication terminal. The TA can be used to estimate the mobile communication terminal's moving speed (more precisely, the radial component of a circle centered on the radio base station), and the UL power control can be used to estimate the distance between the radio base station and the mobile communication terminal. Since these alone cannot derive two-dimensional coordinates indicating the location information of the mobile communication terminal, the location estimation device estimates two-dimensional coordinates by, for example, combining these pieces of information with map information. Here, for example, by adding radio wave propagation information as an additional element of map information, the estimation accuracy of the two-dimensional coordinates can be improved. For example, these processes may be performed by a wireless base station. For example, these processes may be performed by an information processing platform installed in a region, which collects data on the distance between a wireless base station installed in the region and a mobile communication terminal such as a connected car via a wireless base station communicatively connected thereto, as well as map information including information on structures within the coverage area of ​​the wireless base station, and analyzing the data using AI (Artificial Intelligence) or the like to estimate the location of the mobile communication terminal.

[0005] The information processing infrastructure may have a RAN control function that controls a RAN (Radio Access Network) and an AI processing function that performs AI processing.

[0006] Types of AI processing include AI processing related to RAN control (sometimes referred to as RAN-controlled AI processing) and AI processing not related to RAN control (sometimes referred to as non-RAN-controlled AI processing).

[0007] An example of RAN control AI processing is RIC (RAN Intelligent Controller). RIC is a technology that uses AI to optimize RAN radio resources and automate RAN operations. RIC includes Non-RT RIC (Non-Real Time RIC) and Near-RT RIC (Near-Real Time RIC). Non-RT RIC is sometimes called Centralized RIC. Non-RT RIC is located inside SMO (Service Management and Orchestration), which manages and orchestrates the RAN. Non-RT RIC generates and notifies policies related to RAN control and sends information to Near-RT RIC. For example, the Non-RT RIC performs machine learning using data collected from the RAN to generate a trained model for RAN control and transmits it to the Near-RT RIC. The Near-RT RIC is sometimes called a Distributed RIC. Compared to the Non-RT RIC, the Near-RT RIC is located closer to the RAN nodes (RU (Radio Unit), DU (Distributed Unit), CU (Central Unit)) and controls the RAN nodes, resources, etc. The Near-RT RIC performs processing with higher real-time performance than the Non-RT RIC. The Near-RT RIC performs inference processing related to RAN control using, for example, a trained model acquired from the Non-RT RIC. RAN control AI processing is not limited to the RIC.

[0008] The non-RAN control AI processing includes the above-described position estimation processing of the mobile communication terminal, and may also include other processing such as a monitoring AI execution processing that determines the situation within the imaging range of an input captured image, and a response AI execution processing that outputs a response to an input user inquiry.

[0009] According to one embodiment of the present invention, there is provided a position estimation device. The position estimation device may estimate a position of a mobile communications terminal. The position estimation device may include a distance acquisition unit that acquires distance information indicating a distance between the mobile communications terminal and a radio base station that provides mobile communications to the mobile communications terminal, the distance information being obtained by the radio base station performing radio wave measurements on the mobile communications terminal. The position estimation device may include a map acquisition unit that acquires map information including information about structures in a space within a coverage area in which the radio base station provides mobile communications. The position estimation device may include a position estimation unit that estimates the position of the mobile communications terminal in the space within the coverage area based on the distance information and the map information.

[0010] In the position estimation device, the position estimation unit may estimate the position of the mobile communications terminal within a range specified by the distance represented by the distance information centered on the wireless base station in the map information, using information about the structures within the range based on a spherical surface of a sphere centered on the wireless base station and having a radius equal to the distance represented by the distance information in the map information.

[0011] In any of the position estimation devices, the position estimation unit may estimate the position of the mobile communication terminal based on information about the structure within the range and attributes of the mobile communication terminal. The position estimation unit may estimate, as the position of the mobile communication terminal, a position within the range where the structure is located that is likely to be where the mobile communication terminal is located according to the attributes of the mobile communication terminal.

[0012] In any of the position estimation devices, the position estimation unit may estimate the position of the mobile communication terminal based on a change over time in the distance between the wireless base station and the mobile communication terminal. When the distance between the wireless base station and the mobile communication terminal is changing, the position estimation unit may estimate the position of the mobile communication terminal using information on the structures within a range specified by the distance represented by the distance information centered on the wireless base station in the map information at each point in time.

[0013] In any of the position estimation devices, when the distance between the radio base station and the mobile communication terminal has not changed, the position estimation unit may estimate, as the position of the mobile communication terminal, the position of a structure within the range specified by the distance represented by the distance information centered on the radio base station in the map information, where the mobile communication terminal can remain without moving.

[0014] In any of the above position estimation devices, the position estimation unit may, when the distance between the radio base station and the mobile communication terminal has not changed, determine whether the mobile communication terminal is moving based on a change in the radio wave reception strength of the mobile communication terminal, and estimate the position of the mobile communication terminal based on the determination result.

[0015] In any of the position estimation devices, the position estimation unit may estimate the position of the mobile communication terminal using a learning model that estimates the position of the mobile communication terminal from the change over time in the distance between the radio base station and the mobile communication terminal, the model being generated by machine learning using training data including time-series position information of the mobile communication terminal and the change over time in the distance between the radio base station and the mobile communication terminal when the mobile communication terminal moves in the space within the coverage area.

[0016] According to one embodiment of the present invention, there is provided a program for causing a computer to function as the position estimation device.

[0017] According to one embodiment of the present invention, there is provided a position estimation method executed by a computer for estimating the position of a mobile communications terminal. The position estimation method may include a distance acquisition step in which a radio base station providing mobile communications to the mobile communications terminal acquires distance information indicating the distance between the radio base station and the mobile communications terminal, the distance information being obtained by performing radio wave measurements on the mobile communications terminal. The position estimation method may include a map acquisition step in which map information including information on structures in a space within a coverage area in which the radio base station provides mobile communications is acquired. The position estimation method may include a position estimation step in which the position of the mobile communications terminal in the space within the coverage area is estimated based on the distance information and the map information.

[0018] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions.

[0019] FIG. 1 is an explanatory diagram illustrating an example of a system 20. FIG. 2 is an explanatory diagram illustrating an example of position estimation of a mobile communication terminal 400 by a position estimation device 500. FIG. 3 is an explanatory diagram illustrating an example of position estimation of a mobile communication terminal 400 by a position estimation device 500. FIG. 4 is an explanatory diagram illustrating an example of position estimation of a mobile communication terminal 400 by a position estimation device 500. FIG. 5 is an explanatory diagram illustrating an example of position estimation of a mobile communication terminal 400 by a position estimation device 500. FIG. 6 is an explanatory diagram illustrating an example of position estimation of a mobile communication terminal 400 by a position estimation device 500. FIG. 7 is an explanatory diagram illustrating an example of a functional configuration of a position estimation device 500. FIG. 8 is an explanatory diagram illustrating an example of a hardware configuration of a computer 1200 that functions as the position estimation device 500, the information processing infrastructure 100, or the management infrastructure 200.

[0020] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0021] FIG. 1 schematically illustrates an example of a system 20. The system 20 may include a plurality of information processing infrastructures 100. The information processing infrastructures 100 are arranged in corresponding regions 10. In the example illustrated in FIG. 1, the plurality of information processing infrastructures 100 are arranged such that the corresponding regions 10 do not overlap with each other. The plurality of information processing infrastructures 100 may also be arranged such that the corresponding regions 10 overlap with each other. The information processing infrastructure 100 may be an example of a location estimation device.

[0022] The information processing infrastructure 100 may be a data center located in various locations. The information processing infrastructure 100 may be configured by multiple devices. The information processing infrastructure 100 may be realized on a virtualization platform made up of multiple devices. The information processing infrastructure 100 may also be realized by a single device. In other words, the information processing infrastructure 100 may be an information processing device.

[0023] The multiple radio base stations 300 may be arranged in a region 10 corresponding to the information processing infrastructure 100. The region 10 corresponding to the information processing infrastructure 100 may be the region in which the information processing infrastructure 100 is installed. The information processing infrastructure 100 does not have to be installed within the corresponding region 10. The region 10 may be, for example, a region having an area equivalent to that of each prefecture in Japan. The region 10 may be, for example, a region having an area smaller than that of each prefecture in Japan. The region 10 may be, for example, a region having an area larger than that of each prefecture in Japan.

[0024] The communication between the information processing infrastructure 100 and the wireless base station 300 may be any communication means that allows communication between the information processing infrastructure 100 and the wireless base station 300. The communication between the information processing infrastructure 100 and the wireless base station 300 may be wired communication such as communication optical fiber, or may be wireless communication.

[0025] The information processing infrastructure 100 may be equipped with one or more central processing units (CPUs). The information processing infrastructure 100 may be equipped with one or more GPUs. The information processing infrastructure 100 may be equipped with multiple super chips, each of which has a CPU and a GPU connected via an interconnect. The interconnect may have memory consistency and may be capable of achieving high bandwidth and low latency. In this way, the information processing infrastructure 100 may have CPU resources and GPU resources as computational resources.

[0026] The radio base station 300 provides mobile communications to mobile communication terminals within the coverage area of ​​the radio base station 300. A space 42 is a space within the coverage area provided by the radio base station 300. The information processing infrastructure 100 may control a RAN configured by a plurality of radio base stations 300. The radio base station 300 may be an example of a location estimation device. The radio base station 300 may include the location estimation device.

[0027] In the example shown in FIG. 1 , the system 20 may include a management infrastructure 200 that manages multiple information processing infrastructures 100. The management infrastructure 200 may be communicatively connected to multiple information processing infrastructures 100. The management infrastructure 200 may be a data center that manages multiple information processing infrastructures 100. The management infrastructure 200 may be configured with multiple devices. The management infrastructure 200 may be realized on a virtualization infrastructure made up of multiple devices. The management infrastructure 200 may also be realized by a single device. In other words, the management infrastructure 200 may be a management device.

[0028] The management infrastructure 200 may be referred to as a Core Brain, and the information processing infrastructure 100 may be referred to as a Regional Brain. While FIG. 1 illustrates an example in which a single-layer information processing infrastructure 100 is arranged below the management infrastructure 200, this is not limiting. The information processing infrastructure 100 may have multiple layers. For example, when a two-layer information processing infrastructure 100 is arranged below the management infrastructure 200, the management infrastructure 200 may be referred to as a Core Brain, the information processing infrastructure 100 at the layer below that may be referred to as a Regional Brain, and the information processing infrastructure 100 at the layer below that may be referred to as a Sub-Regional Brain. In this case, the position estimation device may be arranged in the Sub-Regional Brain. In this case, the position estimation device may be arranged in the Regional Brain.

[0029] 2 is an explanatory diagram illustrating an example of position estimation of a mobile communication terminal 400 by a position estimation device 500. In the example shown in Fig. 2, a radio base station 300 has a position estimation device 500. In the example shown in Fig. 2, the position estimation device 500 estimates the position of the mobile communication terminal 400.

[0030] In the example shown in FIG. 2 , mobile communication terminal 400 is a communication terminal mounted on an automobile. In this case, mobile communication terminal 400 may be an on-board computer configured to function as a so-called connected car. In the example shown in FIG. 2 , the type of automobile may be any type of automobile. For example, the automobile may be a private car, or an industrial vehicle such as a bus, taxi, or truck. Mobile communication terminal 400 may be any terminal capable of mobile communication. Mobile communication terminal 400 does not have to be mounted on an automobile; it may be mounted on another type of mobility. In this case, by mounting mobile communication terminal 400 on the mobility, the mobility may function as a so-called connected mobility that has the function of an ICT (Information and Communication Technology) terminal. The other type of mobility may be, for example, a railway vehicle in general, or a two-wheeled vehicle such as a motorcycle, bicycle, or moped. The other mobility may be next-generation mobility, personal mobility, ultra-compact mobility, senior car, stroller, etc. The mobility may be manned or unmanned, so-called self-driving mobility. Mobile communication terminal 400 does not have to be mounted on a mobility. Mobile communication terminal 400 may be any terminal capable of mobile communication. Mobile communication terminal 400 may be, for example, a communication terminal such as a smartphone, a mobile phone, a tablet terminal, or a PC (personal computer). For example, mobile communication terminal 400 may move when a user carrying such mobile communication terminal 400 moves on foot or by the various types of mobility described above.

[0031] 2 , a radio base station 300 provides mobile communications to a mobile communication terminal 400. The radio base station 300 performs radio wave measurements on the mobile communication terminal 400. The position estimation device 500 acquires distance information 30 indicating a distance 32 between the radio base station 300 and the mobile communication terminal 400, which is obtained by the radio base station 300 performing radio wave measurements on the mobile communication terminal 400.

[0032] The radio wave measurement may be measuring the time when the radio base station 300 transmits radio waves and the time when the mobile communication terminal 400 receives the radio waves. In this case, the distance information 30 may be the time when the radio base station 300 transmits radio waves and the time when the mobile communication terminal 400 receives the radio waves. The distance information 30 may be the propagation time of the radio waves calculated based on the time when the radio base station 300 transmits the radio waves and the time when the mobile communication terminal 400 receives the radio waves. The distance information 30 may be information on the distance 32 between the radio base station 300 and the mobile communication terminal 400 calculated based on the propagation time and the propagation speed of electromagnetic waves in the atmosphere.

[0033] The radio wave measurement may be measuring the strength of radio waves transmitted by the radio base station 300 and the strength of the radio waves received by the mobile communication terminal 400. In this case, the distance information 30 may be the strength of the radio waves transmitted by the radio base station 300 and the strength of the radio waves received by the mobile communication terminal 400. The distance information 30 may be propagation attenuation of the radio waves calculated based on the strength of the radio waves transmitted by the radio base station 300 and the strength of the radio waves received by the mobile communication terminal 400. The distance information 30 may be information on the distance 32 between the radio base station 300 and the mobile communication terminal 400 calculated based on the propagation attenuation and the attenuation rate of the strength of the electromagnetic waves with respect to the propagation distance in the atmosphere.

[0034] Distance information 30 may be any information that can represent distance 32 between radio base station 300 and mobile communication terminal 400. For example, a parameter value used to control mobile communication provided by radio base station 300 to mobile communication terminal 400 may be used as distance information 30. Distance information 30 may be, for example, a TA (Timing Advance) value.

[0035] In the example shown in Fig. 2 , the space 42 is a space within a coverage area in which the radio base station 300 provides mobile communications. In the example shown in Fig. 2 , a structure 600 is located in the space 42. In the example shown in Fig. 2 , the structure 600 is, but is not limited to, a highway, a general road, a traffic light, a railroad track, a parking lot, a railway station, or a building. The structure 600 may be any structure. For example, the structure 600 may be transportation infrastructure, or may be a public facility such as a commercial facility, a hospital, or a park.

[0036] 2 , the position estimation device 500 acquires map information 40 including information about a structure 600 in a space 42. The map information 40 may include information about the geographic coordinates of the structure 600, information about dimensions including height, and attribute information indicating the type, etc. The map information 40 may include not only information about the structure 600, but also information found on a general map, such as topography, elevation, land use method, etc. The map information 40 may include any information that indicates features within the space 42.

[0037] In the example shown in FIG. 2, the position estimation device 500 estimates the position of the mobile communication terminal 400 in a space 42 within the coverage area based on the distance information 30 and the map information 40 .

[0038] 2 , the position estimation device 500 may estimate the position of the mobile communication terminal 400 within the range 50, using information on structures 600 within the range 50 specified by the distance 32 indicated by the distance information 30 centered on the radio base station 300 in the map information 40. The range 50 may be determined, for example, based on the distance 32 and a buffer distance determined based on a measurement error of the distance 32. The range 50 may be, for example, the space between a spherical surface centered on the radio base station 300 and having a radius equal to the length obtained by subtracting the buffer distance from the distance 32, and another spherical surface centered on the radio base station 300 and having a radius equal to the length obtained by adding the buffer distance to the distance 32. In the example of the plan view shown in FIG. 2 , the range 50 is the range between two circles indicated by dashed lines and centered on the radio base station 300. In the example shown in Figure 2, the position estimation device 500 may estimate the position of the mobile communication terminal 400 within the range 50 by using the map information 40 that indicates that a public road is located within the range 50 as a structure 600.

[0039] 3 is an explanatory diagram illustrating an example of position estimation of mobile communication terminal 400 by position estimation device 500. Position estimation device 500 may estimate the position of mobile communication terminal 400 within range 50 using information on structures 600 within range 50 based on spherical surface 54 of a sphere in map information 40 that has wireless base station 300 at its center and distance 32 indicated by distance information 30 as its radius.

[0040] In the example shown in Fig. 3 , range 50 may be determined based on distance 32 and a buffer distance determined based on a measurement error of distance 32, similar to the example shown in Fig. 2 . In the example shown in Fig. 3 , range 50 may be the space between a spherical surface centered on radio base station 300 and having a radius equal to the length obtained by subtracting the buffer distance from distance 32, and another spherical surface centered on radio base station 300 and having a radius equal to the length obtained by adding the buffer distance to distance 32, similar to the example shown in Fig. 2 . In the plan view example shown in Fig. 3 , range 50 is the range between two circles indicated by dashed lines and centered on radio base station 300. In the example shown in Fig. 3 , position estimation device 500 may estimate the position of mobile communication terminal 400 within range 50 by using the fact that a public road is located within range 50 as a structure 600.

[0041] In the example shown in FIG. 3 , the position estimation device 500 may estimate the position of the mobile communication terminal 400 based on information about the structure 600 within the range 50 and the attributes of the mobile communication terminal 400. The attributes of the mobile communication terminal 400 may be, for example, the type of the mobile communication terminal 400. In the example shown in FIG. 3 , the type of the mobile communication terminal 400 is a communication terminal mounted on an automobile. The attributes of the mobile communication terminal 400 are not limited to the type of the mobile communication terminal 400, and may include, for example, user attributes such as the age, gender, frequently used means of transportation, and frequently used transportation routes of the user of the mobile communication terminal 400. The position estimation device 500 may acquire the attributes of the mobile communication terminal 400 from a function for managing subscriber information of a mobile communication service, such as UDM (Unified Data Management). An external device of system 20, such as a third-party application server, may input information capable of identifying mobile communication terminal 400 and attributes of mobile communication terminal 400 to system 20 via a network exposure function (NEF) or the like, thereby updating the information in the UDM. The external device may directly input information capable of identifying mobile communication terminal 400 and attributes of mobile communication terminal 400 to position estimation device 500. For example, position estimation device 500 may acquire attributes of mobile communication terminal 400 by referring to past position estimation results of mobile communication terminal 400 stored in a storage device accessible to position estimation device 500. When there are multiple candidates for the position of mobile communication terminal 400 within range 50, using the attributes of mobile communication terminal 400 makes it possible to narrow down the candidates, thereby enabling the position of mobile communication terminal 400 to be estimated more accurately and efficiently.

[0042] In the example shown in Fig. 3 , position estimation device 500 may estimate, as the position of mobile communication terminal 400, the position within range 50 where structure 600 is located, where mobile communication terminal 400 is likely to be located according to the attributes of mobile communication terminal 400. In the example shown in Fig. 3 , according to the attribute that mobile communication terminal 400 is a communication terminal mounted on an automobile, position estimation device 500 can narrow down the position of mobile communication terminal 400 to roads and parking lots, as structures 600 where an automobile is likely to be located, and estimate the position of mobile communication terminal 400. In the example shown in Fig. 3 , when structure 600 that is an ordinary road and structure 600 that is a building are candidates for the position of mobile communication terminal 400, position estimation device 500 may estimate that mobile communication terminal 400 is located at the position where structure 600 that is an ordinary road is located. In this way, when there are multiple candidates for the location of mobile communication terminal 400 within range 50, by using the attributes of mobile communication terminal 400, it is possible to narrow down the candidates, and the location of mobile communication terminal 400 can be estimated more accurately and efficiently.

[0043] 3 , position estimation device 500 may estimate, within range 50, a position where structure 600 is located that is unlikely to be the location of mobile communication terminal 400 according to the attributes of mobile communication terminal 400, as not being the location of mobile communication terminal 400. For example, position estimation device 500 may estimate that mobile communication terminal 400 is not located at a position where structure 600 that is a building is located. In this way, when there are multiple candidates for the location of mobile communication terminal 400 within range 50, it is possible to narrow down the candidates by using the attributes of mobile communication terminal 400, and it is possible to estimate the location of mobile communication terminal 400 more accurately and efficiently.

[0044] The position estimation device 500 may not only estimate the position of the mobile communication terminal 400 in a plane, but also estimate the position of the mobile communication terminal 400 in the vertical direction. In the example shown in FIG. 3 , the mobile communication terminal 400 may be a portable terminal such as a smartphone. In this case, it is possible that the user is carrying the mobile communication terminal 400 and is located inside a structure 600 that is a high-rise building. In this case, the position estimation device 500 may estimate which floor of the building the mobile communication terminal 400 is located on. In the example shown in FIG. 3 , the first to fourth floors of the structure 600 that is a high-rise building are located within the range 50, so the position estimation device 500 may estimate that the mobile communication terminal 400 is located on one of the first to fourth floors of the high-rise building.

[0045] The position estimation device 500 may estimate the position of the mobile communication terminal 400 by further using HO (Handover) information indicating from which of the adjacent radio base stations 300 the mobile communication terminal 400 has been handed over. For example, in the example shown in Fig. 3, the position estimation device 500 may further use information that the mobile communication terminal 400 has been handed over from a radio base station 300 that covers the upper floors of a high-rise building to estimate that the mobile communication terminal 400 is located on any one of the first to fourth floors of the high-rise building.

[0046] There are cases where the structure 600 is covered by the coverage areas of multiple radio base stations 300. In this case, the tendency for the mobile communication terminal 400 to frequently connect to a radio base station 300 varies depending on where the mobile communication terminal 400 is located within the structure 600. The position estimation device 500 may estimate the position of the mobile communication terminal 400 by further using the relationship between the location of the mobile communication terminal 400 and the radio base station 300 that is easily connected to. For example, in the example shown in FIG. 3 , the position estimation device 500 may further use information that the mobile communication terminal 400 frequently communicated with a radio base station 300 that is easily connected to on an upper floor of a high-rise building, and estimate that the mobile communication terminal 400 is located on any one of the first to fourth floors of the high-rise building.

[0047] Fig. 4 is an explanatory diagram for explaining an example of position estimation of a mobile communication terminal 400 by a position estimation device 500. In the example shown in Fig. 4, the mobile communication terminal 400 is a communication terminal mounted on an automobile.

[0048] The upper half of Fig. 4 shows an example in which mobile communication terminal 400 enters space 42, then moves along routes A, B, and C in the directions of the arrows, and exits space 42. The lower half of Fig. 4 shows the change over time in distance 32 between radio base station 300 and mobile communication terminal 400 when mobile communication terminal 400 moves as shown in the upper half of Fig. 4. As shown in the lower half of Fig. 4, the change over time in distance 32 is considered to have a certain pattern according to the continuous change in the route of mobile communication terminal 400, i.e., the position of mobile communication terminal 400. Position estimation device 500 may estimate the position of mobile communication terminal 400 further based on the change over time in distance 32 between radio base station 300 and mobile communication terminal 400.

[0049] 4, immediately after mobile communication terminal 400 enters space 42, it is not possible to distinguish between route A and routes B and C, but by observing the subsequent changes over time, it is possible to distinguish whether mobile communication terminal 400 is located on route A or on routes B and C. In this way, when there are multiple candidates for the location of mobile communication terminal 400 within range 50, it is possible to narrow down the candidates by using the change over time in distance 32 between radio base station 300 and mobile communication terminal 400, and the location of mobile communication terminal 400 can be estimated more accurately and efficiently.

[0050] For example, if TA is used as distance information 30, TA is transmitted from radio base station 300 to mobile communication terminal 400 at intervals of approximately 10 milliseconds or more. In other words, time-series location information of distance 32 can be acquired at a frequency of 100 times per second (100 Hz) or more. When a car traveling at 100 km / h passes through a 100-meter section, it takes approximately 3.6 seconds to acquire approximately 360 or more data points. Those skilled in the art will understand that a sufficient amount of data can be acquired to distinguish the above patterns. Note that location estimation device 500 may reduce or compress the data volume of distance information 30 in an appropriate manner.

[0051] In the example shown in FIG. 4 , the position estimation device 500 may estimate the position of the mobile communication terminal 400 using a learning model that estimates the position of the mobile communication terminal 400 from the change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400, the change over time being generated by machine learning using training data including time-series position information of the mobile communication terminal 400 and the change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400 as the mobile communication terminal 400 moves through a space 42 within the coverage area. This model is expected to enable position estimation that is difficult to achieve using theoretical calculations or regression approaches using distance information 30 and map information 40. The time-series position information of the mobile communication terminal 400 may include, for example, the geographic coordinates and time of each point on each route shown in the upper half of FIG. 4 . The change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400 may include, for example, the distance 32 and time of each point shown in the lower half of FIG. 4 .

[0052] In the example shown in Fig. 4, data for times when mobile communication terminal 400 is stopped may be removed from the training data. In the example shown in Fig. 4, information on the time-series movement speed of mobile communication terminal 400 when mobile communication terminal 400 moves through space 42 within the coverage area may be obtained, and the change in distance 32 over time may be normalized based on the movement speed information. This removes noise from the training data, which is expected to improve the position estimation accuracy of the learning model and make learning more efficient.

[0053] The location estimation device 500 may further use traffic information related to a structure 600 in the space 42 within its coverage area to estimate that the mobile communication terminal 400 is located at a position corresponding to the location where the structure 600 is located. In the example shown in FIG. 4 , if the structure 600 is a traffic light, when the traffic light is red, the mobile communication terminal 400 stops at a position corresponding to the location where the traffic light is located for a certain period of time, and then starts moving when the traffic light turns green. In this way, the traffic light imposes certain restrictions on traffic within the space 42, resulting in a specific pattern in the time-series change in the distance 32 between the radio base station 300 and the mobile communication terminal 400. For example, if the traffic light is red at a certain time, the distance 32 does not change at the time corresponding to the red light, and the distance 32 starts to change at the time corresponding to the time when the traffic light turns green, the location estimation device 500 can estimate that the mobile communication terminal 400 is located on a route where the traffic light is located. In this example, the structure 600 is not limited to a traffic light, and may be any structure 600 that imposes certain restrictions on traffic. For example, the structure 600 may be a railroad crossing.

[0054] 5 is an explanatory diagram illustrating an example of position estimation of the mobile communication terminal 400 by the position estimation device 500. The position estimation device 500 may determine whether the distance 32 between the radio base station 300 and the mobile communication terminal 400 has changed. When the distance 32 between the radio base station 300 and the mobile communication terminal 400 has changed, the position estimation device 500 may estimate the position of the mobile communication terminal 400 using information on structures 600 within a range 50 specified by the distance 32 indicated by distance information 30 centered on the radio base station 300 in the map information 40 at each point in time.

[0055] In the example shown in FIG. 5 , mobile communication terminal 400 is a communication terminal mounted on an automobile. Within range 50, four positions are considered as possible locations where mobile communication terminal 400, which is an automobile, may be located: candidate position 72, candidate position 74, candidate position 76, and candidate position 78. Candidate position 72 is located in a parking lot, candidate positions 72 and 74 are located on an ordinary road, and candidate position 78 is located on an expressway. Since distance 32 has changed and it is considered that mobile communication terminal 400 is moving, for example, position estimation device 500 may exclude candidate position 72 from the candidate positions and estimate that mobile communication terminal 400 is located at one of candidate positions 74, 76, and 78. Using information that the traffic light on the ordinary road where candidate position 74 is located is red, position estimation device 500 may exclude candidate position 74 from the candidate positions and estimate that mobile communication terminal 400 is located at one of candidate positions 76 and 78. In this way, by using information on structures 600 within range 50 at each point in time, when there are multiple candidates for the location of mobile communication terminal 400 within range 50, it is possible to narrow down the candidates by using the attributes of mobile communication terminal 400, and the location of mobile communication terminal 400 can be estimated more accurately and efficiently.

[0056] When the distance 32 between the radio base station 300 and the mobile communication terminal 400 is changing, the position estimation device 500 may estimate the position of the mobile communication terminal 400 using information on structures 600 within the range 50 specified by the distance 32 represented by the distance information 30 centered on the radio base station 300 in the map information 40 at each point in time, and the amount of change per unit time in the distance 32. In the example shown in FIG. 5 , when the information indicates that the candidate position 78 is located on a highway and the amount of change in the distance 32 per unit time exceeds a predetermined threshold, the position estimation device 500 may estimate that the mobile communication terminal 400 is located at the candidate position 78. The predetermined threshold may be, for example, the same as the upper speed limit on an ordinary road. In this way, by using the amount of change per unit time in the distance 32, when there are multiple candidates for the position of the mobile communication terminal 400 within the range 50, it is possible to narrow down the candidates by using the attributes of the mobile communication terminal 400, thereby enabling more accurate and efficient estimation of the position of the mobile communication terminal 400.

[0057] When the distance 32 between the radio base station 300 and the mobile communication terminal 400 has not changed, the position estimation device 500 may estimate, as the position of the mobile communication terminal 400, the position of a structure 600 at which the mobile communication terminal 400 can remain without moving, among the structures 600 within the range 50 specified by the distance 32 indicated by the distance information 30 centered on the radio base station 300 in the map information 40. In the example shown in Fig. 5, for example, the position estimation device 500 may estimate that the mobile communication terminal 400 is located at the candidate position 72, which is a parking lot.

[0058] When the distance 32 between the radio base station 300 and the mobile communication terminal 400 remains unchanged, the position estimation device 500 may determine whether the mobile communication terminal 400 is moving based on changes in the radio wave reception strength of the mobile communication terminal 400, and estimate the location of the mobile communication terminal 400 based on the determination result. In the example shown in FIG. 5 , when the mobile communication terminal 400 moves within the range 50, the distance 32 does not change even though the mobile communication terminal 400 is moving. For example, when the mobile communication terminal 400 moves on a public road between the candidate positions 72 and 74, the distance 32 does not change. Here, when the mobile communication terminal 400 does not move, the change in the radio wave reception environment is small, and therefore the change in the radio wave reception strength of the mobile communication terminal 400 is also considered to be small. When the mobile communication terminal 400 moves, the radio wave reception strength of the mobile communication terminal 400 is considered to change in accordance with changes in the radio wave reception environment at each point during movement. Based on this, the position estimation device 500 may determine that the mobile communication terminal 400 is moving if the change in the radio wave reception strength of the mobile communication terminal 400 is greater than a predetermined threshold when the distance 32 between the radio base station 300 and the mobile communication terminal 400 has not changed, and may determine that the mobile communication terminal 400 is not moving if the change in the radio wave reception strength of the mobile communication terminal 400 is less than the predetermined threshold.

[0059] In the example shown in FIG. 5 , the position estimation device 500 may estimate the position of the mobile communication terminal 400 based further on the radio wave reception strength from another radio base station 302 different from the radio base station 300 to the mobile communication terminal 400. The mobile communication terminal 400 may receive radio waves from the other radio base station 302 by so-called neighbor cell search and report the reception strength of the radio waves received from the other radio base station 302 and the identifier (physical cell identity) of the radio base station 302 to the radio base station 300. Although the example shown in FIG. 5 illustrates an example in which there is one other radio base station 302, there may be multiple other radio base stations 302. For example, when the radio wave reception strength between the other radio base station 302 and the mobile communication terminal 400 in the space 42 is within a predetermined threshold range, the position estimation device 500 may estimate that the mobile communication terminal 400 is located within a specific range of the space 42 corresponding to the threshold range. The threshold and the specific range of the space 42 may be determined according to the distance from the other radio base station 302. The threshold may be a smaller value as the distance from the other radio base station 302 increases. In this way, when there are multiple candidates for the location of the mobile communication terminal 400 within the range 50, by further using the radio wave reception strength between the mobile communication terminal 400 and the other radio base station 302 different from the radio base station 300, it is possible to narrow down the candidates, and the location of the mobile communication terminal 400 can be estimated more accurately and efficiently.

[0060] 6 shows an example of the functional configuration of the position estimation device 500. The position estimation device 500 includes a distance acquisition unit 510, a map acquisition unit 520, a position estimation unit 530, and a storage unit 540. It is not essential that the position estimation device 500 includes all of these units. In addition to these "units," the position estimation device 500 may further include any "unit" for realizing the functions of the position estimation device 500.

[0061] The distance acquisition unit 510 acquires distance information 30 indicating the distance 32 between the wireless base station 300 and the mobile communication terminal 400, which is obtained by the wireless base station 300 performing radio wave measurement on the mobile communication terminal 400. The distance acquisition unit 510 may store the acquired information in the storage unit 540.

[0062] The map acquisition unit 520 acquires map information 40 including information about structures 600 in a space 42 within a coverage area in which the radio base station 300 provides mobile communications. The map acquisition unit 520 may acquire position data of the space 42. The position data of the space 42 indicates, for example, the latitude and longitude of the space 42. The map acquisition unit 520 may acquire environmental data indicating the topography within the space 42. The environmental data may be, for example, three-dimensional map data of the space 42. The map acquisition unit 520 may store the acquired information in the storage unit 540.

[0063] The position estimation unit 530 estimates the position of the mobile communication terminal 400 in the space 42 within the coverage area based on the distance information 30 and the map information 40. The position estimation unit 530 may store the estimated position of the mobile communication terminal 400 in the storage unit 540. The position estimation unit 530 may store the estimated position of the mobile communication terminal 400 in the storage unit 540 in a form that allows the time-series position to be determined. For example, the position estimation device 500 may store information on the estimated position of the mobile communication terminal 400 in the storage unit 540 in a form associated with time information. The position estimation unit 530 or the storage unit 540 may output the estimated position information of the mobile communication terminal 400, etc. to a device external to the system 20, such as a third-party application server. The position estimation unit 530 or the storage unit 540 may output the estimated position information of the mobile communication terminal 400, etc. to a device external to the system 20 via the NEF.

[0064] The position estimation unit 530 may estimate the position of the mobile communication terminal 400 within the range 50 identified by the distance 32 represented by the distance information 30 centered on the radio base station 300 in the map information 40, using information on structures 600 within the range 50.

[0065] The position estimation unit 530 may estimate the position of the mobile communication terminal 400 within the range 50 using information on structures 600 within the range 50 based on the spherical surface 54 of a sphere in the map information 40 that is centered on the radio base station 300 and has a radius equal to the distance 32 represented by the distance information 30.

[0066] The position estimation unit 530 may estimate the position of the mobile communication terminal 400 based on information about the structures 600 within the range 50 and the attributes of the mobile communication terminal 400. The position estimation unit 530 may acquire the attributes of the mobile communication terminal 400 by, for example, referring to past position estimation results of the mobile communication terminal 400 stored in a storage device accessible by the position estimation device 500.

[0067] The position estimation unit 530 may estimate the position of the mobile communication terminal 400 as the position within the range 50 where a structure 600 is located that is likely to be where the mobile communication terminal 400 is located based on the attributes of the mobile communication terminal 400.

[0068] The location estimation unit 530 may estimate a location within the range 50 where a structure 600 is located that is unlikely to be the location of the mobile communication terminal 400 according to the attributes of the mobile communication terminal 400, as not being the location of the mobile communication terminal 400.

[0069] The position estimation unit 530 may estimate the position in the height direction of the mobile communication terminal 400. The position estimation unit 530 may estimate the position of the mobile communication terminal 400 by further using HO information indicating from which of the neighboring radio base stations 300 the mobile communication terminal 400 has been handed over.

[0070] The location estimation unit 530 may estimate the location of the mobile communication terminal 400 by further using the relationship between the location of the mobile communication terminal 400 and the radio base station 300 that is easy to connect to. For example, the location estimation unit 530 may estimate that the mobile communication terminal 400 is located on one of the floors of the building by further using information that the mobile communication terminal 400 frequently communicates with the radio base station 300 that is easy to connect to on a particular floor of the building.

[0071] The position estimation unit 530 may estimate the position of the mobile communication terminal 400 further based on the change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400 .

[0072] The position estimation unit 530 may estimate the position of the mobile communication terminal 400 using a learning model that estimates the position of the mobile communication terminal 400 from the change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400, which is generated by machine learning using training data including time-series position information of the mobile communication terminal 400 and the change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400 when the mobile communication terminal 400 moves in the space 42 within the coverage area.

[0073] The position estimation unit 530 may estimate the position of the mobile communication terminal 400 using a learning model that estimates the position of the mobile communication terminal 400 from the change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400, the learning model being generated by machine learning using training data that includes time-series position information of the mobile communication terminal 400 when the mobile communication terminal 400 moves in the space 42 within the coverage area and the change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400, with data for times when the mobile communication terminal 400 is stopped removed.

[0074] The position estimation unit 530 may estimate the position of the mobile communication terminal 400 using a learning model that estimates the position of the mobile communication terminal 400 from the change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400, the learning model being generated by machine learning using training data that includes time-series position information of the mobile communication terminal 400 and the change over time in the distance 32 between the radio base station 300 and the mobile communication terminal 400 when the mobile communication terminal 400 moves in the space 42 within the coverage area, and further adds information on the time-series movement speed of the mobile communication terminal 400 when the mobile communication terminal 400 moves in the space 42 within the coverage area.

[0075] The location estimation unit 530 may further use traffic information related to the structure 600 in the space 42 within the coverage area to estimate that the mobile communication terminal 400 is located at a location corresponding to the location where the structure 600 is located.

[0076] When the distance 32 between the radio base station 300 and the mobile communication terminal 400 is changing, the position estimation unit 530 may estimate the position of the mobile communication terminal 400 using information on a structure 600 within a range 50 specified by the distance 32 represented by the distance information 30 centered on the radio base station 300 in the map information 40 at each time point. When the distance 32 between the radio base station 300 and the mobile communication terminal 400 is changing, the position estimation unit 530 may estimate that the mobile communication terminal 400 is not located at the structure 600 using information on the structure 600 within a range 50 specified by the distance 32 represented by the distance information 30 centered on the radio base station 300 in the map information 40 at each time point.

[0077] When distance 32 between radio base station 300 and mobile communication terminal 400 is changing, location estimation unit 530 may estimate the location of mobile communication terminal 400 using information on structures 600 within range 50 specified by distance 32 represented by distance information 30 centered on radio base station 300 in map information 40 at each point in time, and the amount of change per unit time in distance 32. When the amount of change per unit time in distance 32 between radio base station 300 and mobile communication terminal 400 exceeds a predetermined threshold, location estimation unit 530 may estimate that mobile communication terminal 400 is located at structure 600 that allows high-speed movement. The predetermined threshold may be, for example, the same as the maximum speed limit of the road.

[0078] When the distance 32 between the radio base station 300 and the mobile communication terminal 400 has not changed, the position estimation unit 530 may estimate the position of a structure 600 within the range 50 specified by the distance 32 represented by the distance information 30 centered on the radio base station 300 in the map information 40, where the mobile communication terminal 400 can remain without moving, as the position of the mobile communication terminal 400.

[0079] When the distance 32 between the radio base station 300 and the mobile communication terminal 400 has not changed, the location estimation unit 530 may determine whether the mobile communication terminal 400 is moving based on a change in the radio wave reception strength of the mobile communication terminal 400, and may estimate the location of the mobile communication terminal 400 based on the determination result. When the distance 32 between the radio base station 300 and the mobile communication terminal 400 has not changed, the location estimation unit 530 may determine that the mobile communication terminal 400 is moving if the change in the radio wave reception strength of the mobile communication terminal 400 is greater than a predetermined threshold. When the distance 32 between the radio base station 300 and the mobile communication terminal 400 has not changed, the location estimation unit 530 may determine that the mobile communication terminal 400 is not moving if the change in the radio wave reception strength of the mobile communication terminal 400 is equal to or less than a predetermined threshold.

[0080] The position estimation unit 530 may estimate the position of the mobile communication terminal 400 further based on the radio wave reception strength to the mobile communication terminal 400 from another radio base station 302 different from the radio base station 300. For example, when the radio wave reception strength between the other radio base station 302 and the mobile communication terminal 400 in the space 42 is within a predetermined threshold range, the position estimation device 500 may estimate that the mobile communication terminal 400 is located within a specific range of the space 42 according to the range of the threshold. The threshold and the specific range of the space 42 may be determined according to the distance from the other radio base station 302. The threshold may be a smaller value as the distance from the other radio base station 302 increases.

[0081] 7 schematically illustrates an example of the hardware configuration of a computer 1200 that functions as the location estimation device 500, the information processing infrastructure 100, or the management infrastructure 200. A program installed on the computer 1200 can cause the computer 1200 to function as one or more "parts" of an apparatus according to the present embodiment, or can cause the computer 1200 to perform operations associated with the apparatus according to the present embodiment or one or more "parts," and / or can cause the computer 1200 to perform a process according to the present embodiment or steps of the process. Such a program can be executed by the CPU 1212 to cause the computer 1200 to perform specific operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

[0082] The computer 1200 according to this embodiment includes a CPU 1212, a GPU 1213, a RAM 1214, and a graphics controller 1216, which are interconnected by a host controller 1210. The computer 1200 also includes input / output units such as a communication interface 1222, a storage device 1224, a DVD drive, and an IC card drive, which are connected to the host controller 1210 via an input / output controller 1242. The DVD drive may be a DVD-ROM drive, a DVD-RAM drive, or the like. The storage device 1224 may be a hard disk drive, a solid-state drive, or the like. The computer 1200 also includes a ROM 1230 and a legacy input / output unit such as a keyboard, which are connected to the input / output controller 1242 via an input / output chip 1240.

[0083] The CPU 1212 operates according to programs stored in the ROM 1230 and the RAM 1214, thereby controlling each unit. The graphics controller 1216 acquires image data generated by the CPU 1212 into a frame buffer or the like provided in the RAM 1214 or into the graphics controller 1216 itself, and causes the image data to be displayed on the display device 1218.

[0084] The communication interface 1222 communicates with other electronic devices via a network. The storage device 1224 stores programs and data used by the CPU 1212 in the computer 1200. The DVD drive reads programs or data from a DVD-ROM or the like and provides them to the storage device 1224. The IC card drive reads programs and data from an IC card and / or writes programs and data to an IC card.

[0085] The ROM 1230 stores therein a boot program or the like that is executed by the computer 1200 upon activation, and / or programs that depend on the hardware of the computer 1200. The input / output chip 1240 may also connect various input / output units to the input / output controller 1242 via a USB port, a parallel port, a serial port, a keyboard port, a mouse port, etc.

[0086] The programs are provided by a computer-readable storage medium such as a DVD-ROM or an IC card. The programs are read from the computer-readable storage medium, installed in the storage device 1224, RAM 1214, or ROM 1230, which are also examples of computer-readable storage media, and executed by the CPU 1212. Information processing described in these programs is read by the computer 1200, and brings about cooperation between the programs and the various types of hardware resources described above. An apparatus or a method may be configured by implementing operations or processing of information in accordance with the use of the computer 1200.

[0087] For example, when communication is performed between computer 1200 and an external device, CPU 1212 may execute a communication program loaded into RAM 1214 and instruct communication interface 1222 to perform communication processing based on the processing described in the communication program. Under the control of CPU 1212, communication interface 1222 reads transmission data stored in a transmission buffer area provided in RAM 1214, storage device 1224, a DVD-ROM, or a recording medium such as an IC card, and transmits the read transmission data to a network, or writes received data received from the network to a reception buffer area or the like provided on the recording medium.

[0088] Furthermore, the CPU 1212 may cause all or a necessary portion of a file or database stored in an external recording medium such as the storage device 1224, a DVD drive (DVD-ROM), an IC card, etc. to be read into the RAM 1214, and may perform various types of processing on the data on the RAM 1214. The CPU 1212 may then write back the processed data to the external recording medium.

[0089] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and may undergo information processing. The CPU 1212 may perform various types of processing on data read from the RAM 1214, including various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, information search / replacement, etc., as described throughout this disclosure and specified by the instruction sequences of the programs, and write the results back to the RAM 1214. The CPU 1212 may also search for information in a file, database, etc. on the recording medium. For example, if multiple entries, each having an attribute value of a first attribute associated with an attribute value of a second attribute, are stored on the recording medium, the CPU 1212 may search for an entry whose attribute value of the first attribute matches a specified condition from among the multiple entries, read the attribute value of the second attribute stored in the entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition.

[0090] The above-described programs or software modules may be stored in a computer-readable storage medium on or near the computer 1200. A recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can also be used as a computer-readable storage medium, thereby providing the programs to the computer 1200 via the network.

[0091] The blocks in the flowcharts and block diagrams in the present embodiments may represent stages of a process in which an operation is performed or "parts" of a device responsible for performing the operation. Particular stages and "parts" may be implemented by dedicated circuitry, programmable circuitry provided with computer-readable instructions stored on a computer-readable storage medium, and / or a processor provided with computer-readable instructions stored on a computer-readable storage medium. The dedicated circuitry may include digital and / or analog hardware circuits, and may include integrated circuits (ICs) and / or discrete circuits. The programmable circuitry may include reconfigurable hardware circuits, such as field programmable gate arrays (FPGAs) and programmable logic arrays (PLAs), including AND, OR, XOR, NAND, NOR, and other logical operations, flip-flops, registers, and memory elements.

[0092] A computer-readable storage medium may include any tangible device capable of storing instructions that are executed by an appropriate device, such that a computer-readable storage medium having instructions stored thereon comprises an article of manufacture, including instructions that can be executed to create means for performing the operations specified in the flowcharts or block diagrams. Examples of computer-readable storage media may include electronic, magnetic, optical, electromagnetic, and semiconductor storage media. More specific examples of computer-readable storage media may include floppy disks, diskettes, hard disks, random access memories (RAMs), read-only memories (ROMs), erasable programmable read-only memories (EPROMs or flash memories), electrically erasable programmable read-only memories (EEPROMs), static random access memories (SRAMs), compact disc read-only memories (CD-ROMs), digital versatile discs (DVDs), Blu-ray discs, memory sticks, integrated circuit cards, and the like.

[0093] The computer readable instructions may include either assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, JAVA®, C++, etc., and conventional procedural programming languages ​​such as the “C” programming language or similar programming languages.

[0094] The computer-readable instructions may be provided to a general-purpose computer, a special-purpose computer, or another programmable data processing device processor or programmable circuit, either locally or via a local area network (LAN), a wide area network (WAN) such as the Internet, so that the processor or programmable circuit of the programmable data processing device, such as a computer, executes the computer-readable instructions to generate means for performing the operations specified in the flowcharts or block diagrams. Here, the computer may be a personal computer (PC), a tablet computer, a smartphone, a workstation, a server computer, a general-purpose computer, a special-purpose computer, or the like, or may be a computer system in which multiple computers are connected. Such a computer system in which multiple computers are connected is also called a distributed computing system, and is a broad definition of computer. In a distributed computing system, multiple computers collectively execute a program by each executing a portion of the program and passing data between the computers as needed during program execution.

[0095] Examples of processors include computer processors, central processing units (CPUs), processing units, microprocessors, digital signal processors, controllers, microcontrollers, etc. A computer may have one processor or multiple processors. In a multiprocessor system with multiple processors, each processor executes a portion of a program and passes data between processors as needed during program execution, allowing the multiple processors to collectively execute the program. For example, in multitasking, each of the multiple processors may execute a portion of each task in small chunks by switching tasks at each time slice. In this case, which portion of a program each processor executes changes dynamically. Which portion of a program each of the multiple processors executes may also be statically determined by multiprocessor-aware programming.

[0096] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0097] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order.

[0098] 10 Area, 20 System, 30 Distance information, 32 Distance, 40 Map information, 42 Space, 50 Range, 54 Sphere, 72 Candidate position, 74 Candidate position, 76 Candidate position, 78 Candidate position, 100 Information processing infrastructure, 200 Management infrastructure, 300 Wireless base station, 302 Wireless base station, 400 Mobile communication terminal, 500 Position estimation device, 510 Distance acquisition unit, 520 Map acquisition unit, 530 Position estimation unit, 540 Memory unit, 600 Structure, 1200 Computer, 1210 Host controller, 1212 CPU, 1213 GPU, 1214 RAM, 1216 Graphics controller, 1218 Display device, 1222 Communication interface, 1224 Storage device, 1230 ROM, 1240 Input / output chip, 1242 Input / output controller

Claims

1. A position estimation device that estimates the position of a mobile communications terminal, comprising: a distance acquisition unit that acquires distance information indicating the distance between the mobile communications terminal and a radio base station that provides mobile communications to the mobile communications terminal, the distance information being obtained by the radio base station performing radio wave measurements on the mobile communications terminal; a map acquisition unit that acquires map information including information on structures in a space within a coverage area in which the radio base station provides mobile communications; and a position estimation unit that estimates the position of the mobile communications terminal in the space within the coverage area based on the distance information and the map information.

2. The position estimation device according to claim 1, wherein the position estimation unit uses information about the structures within a range specified by the distance represented by the distance information centered on the wireless base station in the map information to estimate the position of the mobile communication terminal within that range.

3. The position estimation device according to claim 2, wherein the position estimation unit estimates the position of the mobile communications terminal within the range based on the spherical surface of a sphere in the map information, the sphere being centered on the wireless base station and having a radius equal to the distance represented by the distance information.

4. A position estimation device according to claim 2 or 3, wherein the position estimation unit estimates the position of the mobile communication terminal based on information about the structures within the range and attributes of the mobile communication terminal.

5. A position estimation device as described in claim 4, wherein the position estimation unit estimates the position of the mobile communication terminal as the position within the range where the structure where the mobile communication terminal is likely to be located according to the attributes of the mobile communication terminal is located.

6. A position estimation device according to any one of claims 1 to 3, wherein the position estimation unit estimates the position of the mobile communication terminal further based on a change over time in the distance between the radio base station and the mobile communication terminal.

7. A position estimation device as described in claim 6, wherein the position estimation unit estimates the position of the mobile communication terminal using information on the structures within the range specified by the distance represented by the distance information centered on the wireless base station in the map information at each point in time when the distance between the wireless base station and the mobile communication terminal is changing.

8. A position estimation device as described in claim 6, wherein, when the distance between the radio base station and the mobile communication terminal has not changed, the position estimation unit estimates, as the position of the mobile communication terminal, the position of a structure within the range specified by the distance represented by the distance information centered on the radio base station in the map information, where the mobile communication terminal can remain without moving.

9. A position estimation device as described in claim 6, wherein the position estimation unit determines whether the mobile communication terminal is moving based on changes in the radio wave reception strength of the mobile communication terminal when the distance between the radio base station and the mobile communication terminal has not changed, and estimates the position of the mobile communication terminal based on the determination result.

10. A position estimation device as described in any one of claims 1 to 3, wherein the position estimation unit estimates the position of the mobile communication terminal using a learning model that estimates the position of the mobile communication terminal from the change over time in the distance between the radio base station and the mobile communication terminal, the learning model being generated by machine learning using training data including time-series position information of the mobile communication terminal and the change over time in the distance between the radio base station and the mobile communication terminal when the mobile communication terminal moves in the space within the coverage area.

11. A program for causing a computer to function as the position estimation device according to any one of claims 1 to 3.

12. A location estimation method executed by a computer for estimating the location of a mobile communications terminal, comprising: a distance acquisition step in which a radio base station providing mobile communications to the mobile communications terminal acquires distance information indicating the distance between the radio base station and the mobile communications terminal, the distance information being obtained by performing radio wave measurements on the mobile communications terminal; a map acquisition step in which map information is acquired including information on structures in the space within the coverage area in which the radio base station provides mobile communications; and a location estimation step in which the location of the mobile communications terminal in the space within the coverage area is estimated based on the distance information and the map information.

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