KR102314946B1 - Apparatus for estimating distance between wireless communication infrastructures installed at unknown location and method for the same - Google Patents

Abstract

An embodiment of the present invention, the receiving unit for receiving the wireless communication infrastructure measurement information measured at a plurality of measurement points; a neighbor infrastructure determining unit that determines adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information; a measurement point distance calculation unit for calculating measurement point distances, which are distances from each of the measurement points to adjacent wireless communication infrastructures, by using the wireless communication infrastructure measurement information; an infrastructure distance estimator for estimating infrastructure distances, which are distances between the adjacent wireless communication infrastructures, using the measurement point distances; And it provides an apparatus for estimating a distance between wireless communication infrastructures that do not know the installation location, including a storage unit for storing the information and the infrastructure distances of the adjacent wireless communication infrastructure.

Description

Apparatus and method for estimating the distance between wireless communication infrastructures whose installation location is unknown

The present invention relates to an apparatus and method for estimating a distance between wireless communication infrastructures whose installation location is unknown. More specifically, the present invention estimates the distance between a plurality of wireless communication infrastructures whose installation location is unknown by using the wireless communication infrastructure measurement information received from the user terminals at various measurement points, and calculates the distance between the estimated wireless communication infrastructures. It relates to an apparatus and method for providing a precise location-based service in an indoor space using the same.

Location estimation technology using wireless communication infrastructure exists in various ways depending on the type of infrastructure and the range of services.

GPS technologies such as the Global Navigation Satellite System (GNSS), which determine the user's location using satellite signals on the Earth's orbit, cause location errors due to multi-path errors in dense urban areas that are non-line of sight sections. It reaches 50m and it is difficult to determine the position, especially in the indoor area, because the reception sensitivity is lowered and the signal cannot be acquired. In addition, there is also a problem in that the initial positioning time (TTFF: Time To First Fix) is increased due to the degradation of the visible satellite.

Technologies such as Cell-Id and E-OTD (Enhanced-Opserved Time Difference) that determine a user's location using location information and measurement signals of a cellular mobile communication base station have shorter initial positioning time compared to GPS, but Location estimation accuracy varies according to density and has a relatively low location accuracy of about 100 to 800 m on average, making it difficult to apply to indoor and outdoor navigation services that require location accuracy of several meters.

Accordingly, location estimation technology using Wi-Fi has been mainly proposed indoors, and Wi-Fi-based positioning technology is used in buildings indoors and in dense urban areas where GPS is not received or GPS location error is large. Using signal strength, etc., it is possible to provide precise location information of several meters. However, the AP mapping technology using a vehicle has a big problem in the cost required for the initial establishment of the location DB of the Wi-Fi AP. In addition, since the collection is performed in an outdoor area, the collection location uses GPS location information, which has a problem in that it is impossible to acquire the collection location in an indoor area where GPS reception is difficult.

Meanwhile, a location-based service (LBS) may be defined as an information service that provides various information using location information of a recent terminal. Therefore, in order to provide a location-based service to an arbitrary terminal, it is necessary to calculate the location information of the corresponding terminal in advance. However, in order to provide the location of a terminal in an actual environment, particularly in an indoor environment, the location of the installed wireless communication infrastructure must be accurately known or the calculation of the accurate reference location and pattern collection at the reference location must be preceded through a pre-collection process. should be

However, it takes a lot of time and manpower cost to initially acquire the installation location or collection information of the wireless communication infrastructure (eg Wi-Fi AP), and even if the information is initially obtained, changes to the interior And when the wireless communication infrastructure (eg, Wi-Fi AP) is modified/added/changed, a higher cost may be sequentially consumed to update the corresponding information.

Korean Patent Publication No. 10-2011-0011546

An object of the present invention is to estimate a distance between wireless communication infrastructures of unknown installation locations using wireless communication infrastructure measurement information received by a terminal from a plurality of wireless communication infrastructures.

Another object of the present invention is to provide a location-based service using distance information between wireless communication infrastructures.

An embodiment of the present invention, the receiving unit for receiving the wireless communication infrastructure measurement information measured at a plurality of measurement points; a neighbor infrastructure determining unit that determines adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information; a measurement point distance calculation unit for calculating measurement point distances, which are distances from each of the measurement points to adjacent wireless communication infrastructures, by using the wireless communication infrastructure measurement information; an infrastructure distance estimator for estimating infrastructure distances, which are distances between the adjacent wireless communication infrastructures, using the measurement point distances; And it provides an apparatus for estimating a distance between wireless communication infrastructures that do not know the installation location, including a storage unit for storing the information and the infrastructure distances of the adjacent wireless communication infrastructure.

The infrastructure distance estimation unit may estimate the infrastructure distances such that the sum of distance errors corresponding to the respective measurement point distances is minimized.

The apparatus for estimating the distance between the wireless communication infrastructures of which the installation location is unknown may include a service providing unit that provides a location-based service using the infrastructure distances by using the infrastructure distance information.

Under the condition that the infrastructure distance estimator satisfies a triangular inequality in the relationship between the infrastructure distances and the measurement points, and each of the distance errors is less than or equal to the amount of change in the measurement point distance that may occur according to a change in measurement information in a real environment , it is possible to estimate the infrastructure distances such that the sum of the distance errors is minimized.

The measurement point distance calculator may calculate the measurement point distances through a free space path loss model using the received radio strength.

Another embodiment of the present invention, a receiving step of receiving the wireless communication infrastructure measurement information measured at a plurality of measurement points; a neighbor infrastructure determining step of determining adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information; a measurement point distance calculation step of calculating measurement point distances that are distances from each of the measurement points to adjacent wireless communication infrastructures by using the wireless communication infrastructure measurement information; an infrastructure distance estimation step of estimating infrastructure distances, which are distances between the adjacent wireless communication infrastructures, using the measurement point distances; And it provides a method of estimating the distance between the wireless communication infrastructures that do not know the installation location, comprising a storage step of storing the information and the infrastructure distances of the adjacent wireless communication infrastructure.

The infrastructure distance estimation step may estimate the infrastructure distances such that the sum of distance errors corresponding to the respective measurement point distances is minimized.

The method of estimating the distance between the wireless communication infrastructures of which the installation location is unknown may include a service providing step of providing a location-based service using the infrastructure distances using the infrastructure distance information.

In the step of estimating the infrastructure distance, the infrastructure distances satisfy a triangular inequality in relation to the measurement points, and each of the distance errors is less than or equal to the amount of change in the measurement point distance that may occur according to a change in measurement information in a real environment. Thus, it is possible to estimate the infrastructure distances such that the sum of the distance errors is minimized.

The measuring point distance calculation step may calculate the measuring point distances through a free space path loss model using the received radio strength.

Another embodiment of the present invention provides a computer program stored in a medium for executing the method using a computer.

The present invention can estimate the distance between wireless communication infrastructures whose installation location is unknown by using the wireless communication infrastructure measurement information received by the terminal from a plurality of wireless communication infrastructures.

In addition, the present invention can provide a location-based service using distance information between wireless communication infrastructures.

1 is a block diagram illustrating a configuration of an apparatus for estimating a distance between wireless communication infrastructures of unknown installation locations according to an embodiment of the present invention.
2 is an operation flowchart illustrating a method of estimating a distance between wireless communication infrastructures of unknown installation location according to an embodiment of the present invention.
3 is a diagram illustrating an example of measurement information of a plurality of wireless communication infrastructures measured through an arbitrary user terminal at an arbitrary measurement point.
4 is a diagram illustrating an example of measurement information of wireless communication infrastructures collected at various measurement points and locations of some wireless communication infrastructures.
FIG. 5 is a diagram illustrating an example of measurement point distances calculated using RSSI of radio waves received from two wireless communication infrastructures at various measurement points.
6 is a view showing an example of several wireless communication infrastructures inside a building, several measurement points, and adjacent wireless communication infrastructures corresponding to each measurement point.
7 is a diagram illustrating an example of a correlation DB according to a correlation between wireless communication infrastructures and a correlation DB according to distance information between wireless communication infrastructures in the example shown in FIG. 6 .
FIG. 8 is a diagram illustrating an example of a positional relationship between a message sender and a message receiver using a location-based service in an example of a correlation DB according to distance information between wireless communication infrastructures shown in FIG. 7 .
9 is a diagram illustrating another example of a positional relationship between a message sender and a message receiver using a location-based service in an example of a correlation DB according to distance information between wireless communication infrastructures shown in FIG. 7 .
10 is an example of an actual wireless communication environment, showing the hop distribution from each wireless communication infrastructure to other wireless communication infrastructures by comparing the hop distribution using correlations and the hop distribution using the infrastructure distances. It is a drawing.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. Effects and features of the present invention, and a method of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the drawings. Here, repeated descriptions, well-known functions that may unnecessarily obscure the gist of the present invention, and detailed descriptions of configurations will be omitted. The embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer description.

However, the present invention is not limited to the embodiments disclosed below, but all or some of the embodiments may be selectively combined and implemented in various forms. In the following embodiments, terms such as first, second, etc. are used for the purpose of distinguishing one component from another without limiting meaning. Also, the singular expression includes the plural expression unless the context clearly dictates otherwise. In addition, terms such as include or have means that the features or elements described in the specification are present, and do not preclude the possibility that one or more other features or elements will be added.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when described with reference to the drawings, the same or corresponding components are given the same reference numerals, and the overlapping description thereof will be omitted. .

1 is a block diagram illustrating a configuration of an apparatus 100 for estimating a distance between wireless communication infrastructures of unknown installation locations according to an embodiment of the present invention.

Referring to FIG. 1 , an apparatus 100 for estimating a distance between wireless communication infrastructures that do not know an installation location according to an embodiment of the present invention includes a receiving unit 110 , a neighboring infrastructure determining unit 120 , and a measuring point distance calculating unit. 130 , an infrastructure distance estimation unit 140 , and a storage unit 150 .

In addition, the apparatus 100 for estimating the distance between wireless communication infrastructures that do not know the installation location according to an embodiment of the present invention includes the receiving unit 110, the adjacent infrastructure determining unit 120, the measuring point distance calculating unit 130, It includes an infrastructure distance estimation unit 140 , a storage unit 150 , and a service providing unit 160 .

In detail, the receiver 110 receives wireless communication infrastructure measurement information measured from user terminals at a plurality of measurement points in order to estimate the distance between wireless communication infrastructures.

Here, the data receiver 110 may be a device including hardware and software necessary for transmitting and receiving signals such as control signals or data signals through wired/wireless connection with other network devices.

In this case, the wireless communication infrastructure measurement information may be periodically received according to a predetermined period, or may be received from time to time as necessary.

In addition, wireless communication infrastructure measurement information receives radio waves from devices that transmit radio waves for wireless communication and positioning, such as mobile communication base stations, Wi-Fi, BT (Bluetooth), BLE (Bluetooth Low Energy), and UWB (Ultra-Wide Band). It means the data that is measured when it is received. Corresponding data may include identifier, transmit wave strength, transmit frequency, received signal strength indicator (RSSI), round trip time (RTT), angle of arrival (AoA), etc. In addition, it means all information that can be received by being included in standard data for each wireless communication infrastructure.

In addition, the plurality of measurement points refer to points at which the user terminal receives at least one or more pieces of wireless communication infrastructure measurement information in a static or dynamic environment. The user terminal may temporarily or periodically collect the corresponding information through the OS, application program, separate H/W, etc. in the terminal. In addition, the collected wireless communication infrastructure measurement information may be temporarily or permanently stored in a storage device in the terminal, or may be transmitted to a remote server or the like without separate storage.

The adjacent infrastructure determining unit 120 determines adjacent wireless communication infrastructures from among a plurality of wireless communication infrastructures by using the wireless communication infrastructure measurement information.

Here, the adjacent wireless communication infrastructure means a wireless communication infrastructure that is spatially disposed close together, and in the present invention, since the installation location information of the wireless communication infrastructure is not known, the proximity is the maximum between the wireless communication infrastructure sets simultaneously collected at an arbitrary measurement point. It is judged to be adjacent within the wireless communication signal arrival distance.

The measurement point distance calculation unit 130 calculates measurement point distances, which are distances from each measurement point to adjacent wireless communication infrastructures, by using the wireless communication infrastructure measurement information.

Here, the wireless communication infrastructure measurement information includes information such as received radio strength (RSSI), round trip travel time (RTT) or radio arrival reception angle (AoA), which implies the strength of proximity between the terminal and wireless communication infrastructures, This can be used to calculate the measurement point distances.

)을 계산할 수 있다. In addition, in an embodiment of the present invention, the measurement point distance calculation unit 130 calculates the measurement point distances (

) can be calculated.

)와 송신기 신호세기(

)의 관계는, 하기 수학식 1(프리스 공식)과 같이 설계된 무선통신 인프라의 파장(

) 및 송수신 안테나 이득(

,

)으로 표현 가능하다.In detail, the receiver signal strength (

) and transmitter signal strength (

) is the wavelength (

) and transmit and receive antenna gain (

,

) can be expressed as

[Equation 1]

)은 하기 수학식 2와 같이 수신기 신호세기(

)와 송신기 신호세기(

)로 표현 가능하며, 상기 수학식 1을 이용하면 기준거리(

), 설계된 무선통신 인프라의 파장(

) 및 송수신 안테나 이득(

,

)으로 표현 가능하다.Free space path loss at the reference distance (

) is the receiver signal strength (

) and transmitter signal strength (

), and using Equation 1 above, the reference distance (

), the wavelength of the designed wireless communication infrastructure (

) and transmit and receive antenna gain (

,

) can be expressed as

[Equation 2]

)은 하기 수학식 3과 같이 기준거리에서의 자유공간 경로손실(

), 경로 손실 지수(

), 측정지점거리(

) 및 기준거리(

)로 표현 가능하다.Free space path loss at the measurement point distance (

) is the free space path loss (

), the path loss index (

), measuring point distance (

) and reference distance (

) can be expressed as

[Equation 3]

)는 상기 수학식 3을 정리하면 하기 수학식 4와 같이 측정지점거리에서의 자유공간 경로손실(

), 기준거리에서의 자유공간 경로손실(

), 경로 손실 지수(

) 및 기준거리(

)로 표현 가능하다. 또한, 측정지점거리에서의 자유공간 경로손실(

)는 송신기 신호세기(

)와 수신기 신호세기(

)의 차이로 표현 가능하다.Measuring point distance (

) is the free space path loss (

), free space path loss at the reference distance (

), the path loss index (

) and reference distance (

) can be expressed as In addition, the free space path loss at the measurement point distance (

) is the transmitter signal strength (

) and the receiver signal strength (

) can be expressed as the difference between

[Equation 4]

)는 무선통신 인프라의 송신기 신호세기(

), 기준거리에서의 자유공간 경로손실(

), 경로 손실 지수(

), 수신기 신호세기(

)의 함수로 계산할 수 있다. 이 때, 송신기 신호세기(

)는 송신기 사양(specification)에 따라 사전에 주어질 수 있고, 기준거리에서의 자유공간 경로손실(

)은 설계된 무선통신 인프라의 파장(

), 기준거리(

), 송수신 안테나 이득(

,

) 등을 이용하여 사전에 계산될 수 있다. 경로 손실 지수(

) 역시 전파이동환경에 따라 사전에 주어질 수 있다. According to the above equations, the measurement point distance (

) is the transmitter signal strength of the wireless communication infrastructure (

), free space path loss at the reference distance (

), the path loss index (

), receiver signal strength (

) can be calculated as a function of At this time, the transmitter signal strength (

) can be given in advance according to the transmitter specification, and the free space path loss (

) is the wavelength of the designed wireless communication infrastructure (

), the reference distance (

), transmit and receive antenna gain (

,

) can be calculated in advance using path loss index (

) can also be given in advance according to the radio wave movement environment.

)는 수신기 신호세기(

)만의 함수로 계산될 수 있으며, 수신전파세기만 측정되면 측정지점거리(

)를 계산할 수 있다.Therefore, the measurement point distance (the distance from the wireless communication infrastructure to the measurement point)

) is the receiver signal strength (

) can be calculated as a function of only the measurement point distance (

) can be calculated.

The infrastructure distance estimation unit 140 estimates infrastructure distances, which are distances between adjacent wireless communication infrastructures, using the measurement point distances.

In addition, in an embodiment of the present invention, the infrastructure distance estimator 140 may estimate the infrastructure distances such that the sum of distance errors corresponding to the respective measurement point distances is minimized. Since the measurement point distance calculator 130 calculates the measurement point distance from the wireless communication infrastructure measurement information collected from the user's terminals, the distance and error between the actual measurement point and the target wireless communication infrastructure may occur. Accordingly, if the infrastructure distances at which the sum of distance errors, which are errors of the measurement point distances, are minimized, the probability of approaching the actual distance between wireless communication infrastructures increases.

In addition, in an embodiment of the present invention, the infrastructure distance estimator 140 may use linear programming to solve the problem of minimizing the sum of distance errors. In particular, under the condition that the infrastructure distances satisfy the triangular inequality in relation to the measurement points, and that each of the distance errors is less than or equal to the amount of change in the measurement point distance that may occur according to the change of measurement information in the real environment, the distance errors It is possible to estimate the infrastructure distances such that the sum is minimized.

)는 각각의 측정지점들에 대해서 하기 수학식 5의 삼각부등식을 충족하여야 한다. 또한, 거리오차들(

,

) 각각에 대해서, 하기 수학식 6 및 수학식 7과 같이, 실 환경에서 측정정보의 변화에 따라 발생할 수 있는 측정지점거리의 변화량(

,

)보다 작거나 같도록 제한한다. 하기 수학식 5 내지 7을 만족하면서, 오차거리들의 합(

)이 최소가 되도록 인프라거리(

)를 정한다. For example, when estimating the infrastructure distance in an environment where there are wireless communication infrastructure m, wireless communication infrastructure n, and N measurement points, the infrastructure distance (

) must satisfy the trigonometric inequality of Equation 5 below for each measurement point. Also, distance errors (

,

) for each, as shown in Equations 6 and 7 below, the amount of change (

,

) to be less than or equal to While satisfying the following Equations 5 to 7, the sum of the error distances (

) to minimize the infrastructure distance (

) is determined.

[Equation 5]

[Equation 6]

[Equation 7]

는 무선통신 인프라 m과 측정지점 k와의 계산된 측정지점거리,

는 무선통신 인프라 n과 측정지점 k와의 계산된 측정지점거리,

는

에 상응하는 거리오차,

는

에 상응하는 거리오차,

는

에 상응하는 측정지점거리의 변화량,

는

에 상응하는 측정지점거리의 변화량,

은 무선통신 인프라 m과 무선통신 인프라 n 사이의 인프라거리이다.At this time,

is the calculated measurement point distance between the wireless communication infrastructure m and the measurement point k,

is the calculated measurement point distance between the wireless communication infrastructure n and the measurement point k,

Is

corresponding distance error,

Is

corresponding distance error,

Is

The amount of change in the measurement point distance corresponding to

Is

The amount of change in the measurement point distance corresponding to

is the infrastructure distance between the wireless communication infrastructure m and the wireless communication infrastructure n.

In addition, in using the linear programming method, conditions according to the type of wireless communication infrastructure and the structure of the measurement space may be added.

The storage unit 150 stores information and infrastructure distances of adjacent wireless communication infrastructures. Here, the information of adjacent wireless communication infrastructures may include information such as adjacent wireless communication infrastructure set information, received radio strength (RSSI), RTT, AoA, etc. indicating the strength of proximity between wireless communication infrastructures and measurement points. Furthermore, information such as wireless communication infrastructure measurement information or measurement point distances collected from various measurement points may be stored.

The service provider 160 may provide a location-based service based on the shortest distance between wireless communication infrastructures by using the estimated infrastructure distance information.

In the past, a location-based service based on a layer according to the correlation between wireless communication infrastructures was provided, but in an embodiment of the present invention, a location-based service based on distance information between wireless communication infrastructures is provided to provide a more accurate location-based service. can

2 is an operation flowchart illustrating a method of estimating a distance between wireless communication infrastructures of unknown installation location according to an embodiment of the present invention.

Referring to FIG. 2 , the method for estimating the distance between wireless communication infrastructures of unknown installation location according to an embodiment of the present invention is an apparatus for estimating the distance between wireless communication infrastructures whose installation location is unknown (see 100 in FIG. 1 ). A, receives wireless communication infrastructure measurement information measured at a plurality of measurement points (S201).

In this case, the wireless communication infrastructure measurement information may be periodically received according to a predetermined period, or may be received from time to time as necessary.

In addition, wireless communication infrastructure measurement information receives radio waves from devices that transmit radio waves for wireless communication and positioning, such as mobile communication base stations, Wi-Fi, BT (Bluetooth), BLE (Bluetooth Low Energy), and UWB (Ultra-Wide Band). It means the data that is measured when it is received. Corresponding data may include identifier, transmit wave strength, transmit frequency, received signal strength indicator (RSSI), round trip time (RTT), angle of arrival (AoA), etc. In addition, it means all information that can be received by being included in standard data for each wireless communication infrastructure.

In addition, in the method for estimating the distance between wireless communication infrastructures whose installation location is unknown according to an embodiment of the present invention, an apparatus for estimating the distance between wireless communication infrastructures whose installation location is unknown (see 100 in FIG. 1 ) includes wireless communication The adjacent wireless communication infrastructures are determined using the infrastructure measurement information (S203).

Here, the adjacent wireless communication infrastructure means a wireless communication infrastructure that is spatially disposed close together, and in the present invention, since the installation location information of the wireless communication infrastructure is not known, the proximity is the maximum between the wireless communication infrastructure sets simultaneously collected at an arbitrary measurement point. It is judged to be adjacent within the wireless communication signal arrival distance.

In addition, in the method for estimating the distance between wireless communication infrastructures whose installation location is unknown according to an embodiment of the present invention, an apparatus for estimating the distance between wireless communication infrastructures whose installation location is unknown (see 100 in FIG. 1 ) includes wireless communication Measurement point distances from each measurement point to adjacent wireless communication infrastructures are calculated using the infrastructure measurement information (S205).

Here, the wireless communication infrastructure measurement information includes information such as received radio strength (RSSI), round trip travel time (RTT) or radio arrival reception angle (AoA), which implies the strength of proximity between the terminal and wireless communication infrastructures, This can be used to calculate the measurement point distances.

)는 무선통신 인프라의 송신기 신호세기(

), 기준거리에서 자유공간 경로손실 모델(

), 경로 손실 지수(

), 수신기 신호세기(

)의 함수로 계산할 수 있다. 이 때, 송신기 신호세기(

)는 송신기 사양(specification)에 따라 사전에 주어질 수 있고, 기준거리에서 자유공간 경로손실 모델(

)은 설계된 무선통신 인프라의 파장(

), 기준거리(

), 송수신 안테나 이득(

,

) 등을 이용하여 사전에 계산될 수 있다. 경로 손실 지수(

) 역시 전파이동환경에 따라 사전에 주어질 수 있다. Furthermore, it is possible to calculate the measurement point distances through the free space path loss model using the received propagation strength. Measuring point distance (

) is the transmitter signal strength of the wireless communication infrastructure (

), the free-space pathloss model at the reference distance (

), the path loss index (

), receiver signal strength (

) can be calculated as a function of At this time, the transmitter signal strength (

) can be given in advance according to the transmitter specification, and the free-space pathloss model (

) is the wavelength of the designed wireless communication infrastructure (

), the reference distance (

), transmit and receive antenna gain (

,

) can be calculated in advance using path loss index (

) can also be given in advance according to the radio wave movement environment.

)는 수신기 신호세기(

)만의 함수로 계산될 수 있으며, 수신전파세기만 측정되면 측정지점거리(

)를 계산할 수 있다.Therefore, the measurement point distance (the distance from the wireless communication infrastructure to the measurement point)

) is the receiver signal strength (

) can be calculated as a function of only the measurement point distance (

) can be calculated.

In addition, in the method for estimating the distance between wireless communication infrastructures of unknown installation location according to an embodiment of the present invention, an apparatus for estimating the distance between wireless communication infrastructures of unknown installation location (see 100 in FIG. 1 ) is a measurement point Infrastructure distances between adjacent wireless communication infrastructures are estimated using the distances (S207).

In this case, the infrastructure distances may be estimated so that the sum of distance errors corresponding to the respective measurement point distances calculated in step S205 is minimized. Since the measurement point distance is calculated from the wireless communication infrastructure measurement information collected from the user's terminals, the distance and error between the actual measurement point and the target wireless communication infrastructure may occur. Accordingly, if the infrastructure distances at which the sum of distance errors, which are errors of the measurement point distances, are minimized, the probability of approaching the actual distance between wireless communication infrastructures increases.

And, in estimating the infrastructure distances, linear programming can be used to solve the problem of minimizing the sum of distance errors. In particular, under the condition that the infrastructure distances satisfy the triangular inequality in relation to the measurement points, and that each of the distance errors is less than or equal to the amount of change in the measurement point distance that may occur according to the change of measurement information in the real environment, the distance errors It is possible to estimate the infrastructure distances such that the sum is minimized.

In addition, in using the linear programming method, conditions according to the type of wireless communication infrastructure and the structure of the measurement space may be added.

In addition, in the method for estimating the distance between wireless communication infrastructures of unknown installation location according to an embodiment of the present invention, an apparatus for estimating the distance between wireless communication infrastructures of unknown installation location (refer to 100 in FIG. 1 ) includes an adjacent wireless Information and infrastructure distances of communication infrastructures are stored (S209). Here, the information of adjacent wireless communication infrastructures may include information such as adjacent wireless communication infrastructure set information, received radio strength (RSSI), RTT, AoA, etc. indicating the strength of proximity between wireless communication infrastructures and measurement points.

Furthermore, information such as wireless communication infrastructure measurement information or measurement point distances collected from various measurement points may be stored.

In addition, in the method for estimating the distance between wireless communication infrastructures whose installation location is unknown according to an embodiment of the present invention, an apparatus for estimating the distance between wireless communication infrastructures whose installation location is unknown (see 100 in FIG. 1 ) includes wireless communication A location-based service is provided based on the shortest distance between infrastructures (S211).

In the past, a location-based service based on a layer according to the correlation between wireless communication infrastructures was provided, but in an embodiment of the present invention, a location-based service based on distance information between wireless communication infrastructures is provided to provide a more accurate location-based service. can

In an optional embodiment, in the steps S201, S203, S205, S207, S209 and S211, the step of determining the adjacent wireless communication infrastructures (S203) and the step of calculating the measurement point distances (S205) are performed in parallel can be performed.

In an optional embodiment, in the steps S201, S203, S205, S207, S209 and S211, the step of providing the location-based service (S211) is the step of storing information and infrastructure distances of adjacent wireless communication infrastructures (S209). ) can be performed earlier.

In an optional embodiment, in the steps S201, S203, S205, S207, S209 and S211, the step of providing the location-based service (S211) is the step of storing information and infrastructure distances of adjacent wireless communication infrastructures (S209). ) can be performed in parallel.

3 is a diagram illustrating an example of measurement information of a plurality of wireless communication infrastructures measured through an arbitrary user terminal at an arbitrary measurement point.

Referring to FIG. 3 , for example, it is assumed that a list of four Wi-Fi APs is measured through an arbitrary user terminal at an arbitrary measurement point. At this time, four Wi-Fi APs (CCC, AAA, BBB, EEE) are physically adjacent to each other within the maximum radio wave reach of the Wi-Fi AP centered on the user terminal, and the four Wi-Fi APs are adjacent to wireless communication. determined by the infrastructure.

FIG. 3 shows Wi-Fi APs and corresponding RSSI information. If the RSSI has a large value, it means that the user terminal is in a close distance to the corresponding wireless communication infrastructure.

Accordingly, in the example shown in FIG. 3 , it may be determined that the four Wi-Fi APs are close to the user terminal or the measurement point in the order of CCC, AAA, BBB, and EEE.

4 is a diagram illustrating an example of measurement information of wireless communication infrastructures collected at various measurement points and locations of some wireless communication infrastructures.

Referring to FIG. 4 , various wireless communication infrastructure measurement information includes information on adjacent wireless communication infrastructures corresponding to each of them. For example, according to the wireless communication infrastructure measurement information collected at the measurement point 1, the Wi-Fi APs at the measurement point 1 are arranged closely in the order of AAA, BBB, CCC, DDD, and EEE, and the wireless communication infrastructure collected at the measurement point 2 According to the communication infrastructure measurement information, at measurement point 2, Wi-Fi APs are located close to each other in the order of BBB, CCC, AAA, and DDD.

In addition, referring to FIG. 4 , (a), which is the distance from the Wi-Fi AP BBB and CCC to an arbitrary measurement point, is the measurement point distance, and (b), which is the distance between the Wi-Fi AP BBB and CCC, is the infrastructure distance. am.

Measurement point distances can be calculated through information such as RSSI, RTT, and AoA included in the wireless communication infrastructure measurement information collected at each measurement point, and the infrastructure distance is the sum of distance errors included in the measurement point distances. It can be determined by estimating a value that minimizes .

5 is a view showing an example of the measurement point distances calculated by using the received radio intensity (RSSI) of radio waves received from two wireless communication infrastructures at various measurement points.

,

)을 계산할 수 있으며, 각각의 측정지점거리들에는 상응하는 측정지점과 AP와의 실제 거리들(예:

,

) 과의 차이인 오차거리(예:

,

)들이 포함되어 있다.Referring to FIG. 5 , measurement point distances (eg, using RSSI) measured at AP m and AP n at each measurement point are used.

,

) can be calculated, and for each measurement point distance, the actual distances between the corresponding measurement point and the AP (eg:

,

), which is the difference from the error distance (e.g.:

,

) are included.

)을 추정함에 있어서, 측정지점거리들을 이용하여 오차거리들의 합이 최소가 되도록 하는 인프라거리를 실제 인프라거리로 추정할 수 있다. 즉,

가 최소가 되는 인프라거리(

)를 찾을 수 있다.And the infrastructure distance (the distance between AP m and AP n)

), the actual infrastructure distance can be estimated as the infrastructure distance that minimizes the sum of the error distances using the measurement point distances. in other words,

The infrastructure distance where is the minimum (

) can be found.

6 is a view showing an example of several wireless communication infrastructures inside a building, several measurement points, and adjacent wireless communication infrastructures corresponding to each measurement point.

Referring to FIG. 6 , according to the wireless communication infrastructure measurement information collected at measurement point 1 (user participation 1), AP AAA, BBB, and CCC constitute a set of adjacent wireless communication infrastructures; According to the wireless communication infrastructure measurement information collected at the measurement point 2 (user participation 2), AP AAA, CCC, DDD, EEE constitute a set of adjacent wireless communication infrastructures; According to the wireless communication infrastructure measurement information collected at measurement point 3 (user participation 3), AP BBB and FFF constitute a set of adjacent wireless communication infrastructures; According to the wireless communication infrastructure measurement information collected at measurement point 4 (user participation 4), AP FFF and GGG constitute a set of adjacent wireless communication infrastructures; For AP HHH, since there is no wireless communication infrastructure measurement information collected, it does not constitute a set of adjacent wireless communication infrastructures.

Wireless communication infrastructures within the same adjacent wireless communication infrastructure set can be determined to be adjacent to each other, and the existing location-based services are layered through correlation such as how many adjacent wireless communication infrastructure sets pass between specific wireless communication infrastructures. based on the number.

7 is a diagram illustrating an example of a correlation DB according to a correlation between wireless communication infrastructures and a correlation DB according to distance information between wireless communication infrastructures in the example shown in FIG. 6 .

Referring to the left part of FIG. 7 and FIG. 6 , it can be seen that APs included in the same adjacent wireless communication infrastructure set have a correlation of 1. For example, AP DDD and AP CCC belong to the same adjacent wireless communication infrastructure set by the wireless communication infrastructure measurement information collected at measurement point 2 (user participation 2) shown in FIG. . Accordingly, AP DDD and AP BBB span two sets of adjacent wireless communication infrastructures, so that the correlation or layer becomes 2.

However, referring to the right part of FIG. 7 , by displaying the infra distances in meters (m) instead of layers between respective wireless communication infrastructures, it is possible to more accurately describe the actual closeness between various wireless communication infrastructures. For example, in the correlation DB according to the layer, the case from AP DDD to AP EEE or from AP DDD to AP CCC corresponds to layer 1 and has the same adjacency; In the correlation DB according to the infrastructure distance, the distance from AP DDD to AP EEE is 10 meters, and in the case from AP DDD to AP CCC, the distance is 20 meters, so the adjacency is doubled.

Therefore, when the correlation DB according to the correlation between wireless communication infrastructures is used, the distance between the wireless communication infrastructures cannot be directly estimated, and the correlation DB according to the distance information between the wireless communication infrastructures reflects the wireless communication infrastructure distribution more accurately , can provide better location-based services.

FIG. 8 is a diagram illustrating an example of a positional relationship between a message sender and a message receiver using a location-based service in an example of a correlation DB according to distance information between wireless communication infrastructures shown in FIG. 7 .

The message sender can be a store owner who provides contents such as coupons to nearby people using location-based services, and the message receiver uses location-based services to provide contents such as discount coupons for nearby stores It could be a customer, etc.

Referring to FIG. 8 , the message sender using the location-based service is located closest to the AP GGG corresponding to the wireless communication infrastructure, the message receiver a is located closest to the AP FFF, and the message receiver b is located closest to the AP DDD.

Accordingly, the message receiver a has a correlation of 1 from the message sender, and the shortest distance between wireless communication infrastructures is 15 meters. And the message receiver b corresponds to correlation 4 from the message sender, and the shortest distance between wireless communication infrastructures corresponds to 75 meters.

If the range of message transmission in the location-based service is divided into layer 1 to layer 5 based on the layer according to the correlation, message recipient a can receive all layers 1 to 5, and message recipient b Layer 4 through layer 5 can be received.

If the range of message transmission in the location-based service is divided into 10 meters, 30 meters, 50 meters, 70 meters, and 100 meters based on the distance information between wireless communication infrastructures, the message receiver a is 30 meters, 50 meters, 70 meters. It is possible to receive in the range of meters and 100 meters, and message receiver b can only receive it in the range of 100 meters.

Although the sum of the infrastructure distances from the message sender is 75 meters, the message receiver b has a correlation of 4 even though it is relatively far away, and it can be determined that the message receiver b is relatively close, and the message receiver a is 15 meters away from the message sender However, the correlation is determined to be 1, and there is a possibility that the correlation is determined to be relatively close depending on the message transmission range.

If the message transmission range is determined based on the sum of the infrastructure distances between the message receiver and the message sender, the message receiver and the sender can receive a more accurate and reliable location-based service. However, when the message transmission range is determined based on the correlation between the message receiver and the message sender, the message receiver and the sender are provided with a location-based service in which distance information is incorrectly reflected.

9 is a diagram illustrating another example of a positional relationship between a message sender and a message receiver using a location-based service in an example of a correlation DB according to distance information between wireless communication infrastructures shown in FIG. 7 .

9, the message sender using the location-based service is located closest to the AP CCC corresponding to the wireless communication infrastructure, the message receiver a is in the AP FFF, the message receiver b is in the AP DDD, and the message receiver c is the AP GGG. located closest to

Accordingly, the message receiver a has a correlation of 2 from the message sender, and the shortest distance between wireless communication infrastructures is 40 meters. And the message receiver b corresponds to correlation 1 from the message sender, and the shortest distance between wireless communication infrastructures is 20 meters. And the message receiver c corresponds to correlation 3 from the message sender, and the shortest distance between wireless communication infrastructures is 55 meters.

If the range of message transmission in the location-based service is divided into layer 1 to layer 5 based on the layer according to the correlation, message receiver a can receive from layer 2 to layer 5, and message receiver b is layered All levels from 1 to 5 can be received. In addition, the message receiver c can receive from layer 3 to layer 5.

If the range of message transmission in the location-based service is divided into 10 meters, 30 meters, 50 meters, 70 meters, and 100 meters based on the distance information between wireless communication infrastructures, message receiver a is 50 meters, 70 meters and 100 meters. Reception is possible at a range of meters, and message receiver b is capable of receiving at ranges of 30 meters, 50 meters, 70 meters and 100 meters. In addition, the message receiver c is capable of receiving in ranges of 70 meters and 100 meters.

Although the sum of the infrastructure distances from the message sender is 40 meters, the correlation is determined as 2, and the message receiver a can be determined to be relatively close, and the message receiver b is 20 meters away from the message sender. However, the correlation is determined to be 1, and there is a possibility that the correlation is determined to be relatively close depending on the message transmission range. In addition, although the sum of the infrastructure distances from the message sender c is relatively far away from the message sender c, there is a possibility that the correlation is determined as 3 and thus relatively close.

10 is an example of an actual wireless communication environment, showing the hop distribution from each wireless communication infrastructure to other wireless communication infrastructures by comparing the hop distribution using correlations and the hop distribution using the infrastructure distances. It is a drawing.

In detail, FIG. 10 shows the calculation of the shortest distance between the target wireless communication infrastructure (eg, Wi-Fi AP) in each identifiable wireless communication infrastructure (eg, Wi-Fi AP) received from four floors of a building. The number of layers using correlations without using distance information (left) and the number of layers using distance information (right) are compared. The x-axis represents the ID of a wireless communication AP, which is a starting standard for shortest distance estimation, and the y-axis represents the distribution ratio of the number of layers of each target wireless communication infrastructure.

Referring to FIG. 10 , assuming that a location-based service for a target terminal is provided within four floors of a building, when distance information is not used, most of the location-based services for a target terminal within three floors (eg: discount coupons may be provided). In other words, if the criteria that can be set for the location-based service are based on correlation, the service can only be provided by setting the layer to a value between 1 and 3, so that a very approximate and inaccurate location-based service is provided. do.

On the other hand, when distance information is used, location-based services (eg, discount coupons) can be provided subdivided within 6 layers by reflecting the distance information estimated between layers. In particular, since it is possible to set a distance standard (eg 50m) that is commonly used in the existing location-based service, it is possible to provide a customized location-based service to the target terminal by triggering it more accurately.

In particular, in that the range of the location-based service can be determined by using distance information, the compatibility with the previously designed location-based service is large, and the setting criteria are intuitive and clear.

In addition, the more the wireless communication infrastructure measurement information is accumulated, the more accurate the estimated distance information between the wireless communication infrastructures can be obtained. Even if the wireless communication infrastructure is previously installed or removed, the latest measurement There is also the advantage of being able to update it by using the information.

Above all, it is possible to provide location-based services in the indoor environment by accumulating a plurality of wireless communication infrastructure measurement information provided by the user terminal without initial collection in an indoor environment and estimating the correlation DB and distance information between wireless communication infrastructures based on this. This point can be said to be a great contribution of the present invention.

On the other hand, the method of estimating the distance between the wireless communication infrastructures of which the installation location is unknown is implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable recording medium. In this case, the computer-readable recording medium may include program instructions, data files, data structures, etc. alone or in combination. On the other hand, the program instructions recorded on the recording medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software.

The computer-readable recording medium includes magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and magnetic media such as floppy disks. Includes optical media (Magneto-Optical Media), and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. On the other hand, such a recording medium may be a transmission medium such as an optical or metal wire or waveguide including a carrier wave for transmitting a signal designating a program command, a data structure, and the like.

As described above, in the apparatus and method for estimating the distance between wireless communication infrastructures of unknown installation location according to the present invention, the configuration and method of the embodiments described above are not limitedly applicable, but the above embodiment All or part of each embodiment may be selectively combined so that various modifications may be made.

110: A device for estimating the distance between wireless communication infrastructures that do not know the installation location
110: Receiver 120: Neighboring Infrastructure Determination Unit
130: measurement point distance calculation unit 140: infrastructure distance estimation unit
150: storage unit 160: service provider

Claims (7)

a receiver for receiving wireless communication infrastructure measurement information measured at a plurality of measurement points;
a neighbor infrastructure determining unit that determines adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information; and
Including an infrastructure distance estimator for estimating infrastructure distances that are distances between the adjacent wireless communication infrastructures,
The adjacent wireless communication infrastructures
Apparatus for estimating the distance between wireless communication infrastructures, characterized in that determined based on a set of adjacent wireless communication infrastructures corresponding to the plurality of measurement points. delete delete The method according to claim 1,
The set of adjacent wireless communication infrastructure is
Distance between wireless communication infrastructures of unknown installation location, characterized in that the terminal corresponds to measurement information simultaneously collected at any one of the measurement points at which the terminal receives at least one or more wireless communication infrastructure measurement information in a static or dynamic environment estimating device. The method according to claim 1,
The infrastructure distances are
Apparatus for estimating the distance between wireless communication infrastructures of unknown installation location, characterized in that calculated using measurement point distances, which are distances from each of the measurement points to adjacent wireless communication infrastructures. The method according to claim 1,
The infrastructure distance estimation unit
Apparatus for estimating the distance between wireless communication infrastructures that do not know the installation location, characterized in that for estimating the infrastructure distances without knowing the installation location information of each of the wireless communication infrastructures. A receiving step of receiving wireless communication infrastructure measurement information measured at a plurality of measurement points;
a neighbor infrastructure determining step of determining adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information; and
Including an infrastructure distance estimation step of estimating infrastructure distances that are distances between the adjacent wireless communication infrastructures,
The adjacent wireless communication infrastructures
A method for estimating a distance between wireless communication infrastructures of unknown installation location, characterized in that it is determined based on a set of adjacent wireless communication infrastructures corresponding to the plurality of measurement points.

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