KR20180104921A - 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 provides an apparatus for estimating a distance between wireless communication infrastructures installed at unknown locations, which includes: a receiving unit for receiving wireless communication infrastructure measurement information measured at a plurality of measurement points; an adjacent infrastructure determining unit for determining adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information; a measurement point distance calculating unit for calculating measurement point distances that are distances from the measurement points to the adjacent wireless communication infrastructures, respectively, using the wireless communication infrastructure measurement information; an infrastructure distance estimating unit for estimating infrastructure distances that are distances between the adjacent wireless communication infrastructures using the measurement point distances; and a storage unit for storing information on the adjacent wireless communication infrastructures and the infrastructure distances. Accordingly, the present invention can estimate the distance between the wireless communication infrastructures installed at the unknown locations and provide a location-based service using distance information between the wireless communication infrastructures.

Description

[0001] APPARATUS FOR ESTIMATING DISTANCE BETWEEN WIRELESS COMMUNICATION INFRASTRUCTURES INSTALLED AT UNKNOWN LOCATION AND METHOD FOR THE SAME [0002]

The present invention relates to an apparatus and a method for estimating the distance between wireless communication infrastructures that do not know the installation location. More specifically, the present invention estimates the distance between a plurality of wireless communication infrastructures that do not know the installation location 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 To provide a precise location-based service in an indoor space, and a method thereof.

The location estimation technology using wireless communication infrastructure exists in various ways depending on the type of infrastructure and service range.

GPS technologies such as the Global Navigation Satellite System (GNSS) that determines the user's position using the satellite signals on the earth's orbits can be used in a non-line-of-sight area, 50m. Especially in the indoor area, it is difficult to determine the position because the reception sensitivity is decreased and the signal can not be acquired. Also, there arises a problem that the initial positioning time (TTFF: Time To First Fix) due to the drop of the visible satellite is prolonged.

Techniques such as Cell-Id and Enhanced-Opserved Time Difference (E-OTD) that determine the location of a user using location information and measurement signals of a cellular mobile communication base station have a shorter initial positioning time than GPS, It is difficult to apply to the indoor and outdoor navigation service that requires a position accuracy of about several meters due to a relatively low position accuracy of about 100 to 800 m on the average.

Wi-Fi-based positioning technology has been widely used in Wi-Fi APs in indoors and downtown areas where GPS is not received or GPS position error is large. It is possible to provide accurate position information of several meters level by using the signal intensity. However, the AP mapping technique using the vehicle has a problem of a large cost for initial construction of the location DB of the Wi-Fi AP. Also, since the collection is performed in the outdoor area, the GPS location information is used for the collection location, which is a problem in that it is impossible to acquire the collection location in the indoor area where GPS reception is difficult.

Meanwhile, a location based service (LBS) can be defined as an information service that provides various information using location information of a terminal. Therefore, in order to provide a location-based service for an arbitrary terminal, the location information of the terminal must be calculated. However, in order to provide the location of the terminal in the actual environment, especially indoor environment, it is necessary to know the location of the installed wireless communication infrastructure accurately or to calculate the accurate reference position through the pre-collection process and to collect the pattern at the reference position .

However, much time and manpower costs are consumed initially to acquire the installation location or collection information of the corresponding wireless communication infrastructure (eg, Wi-Fi AP), and even if this information is initially acquired, And a wireless communication infrastructure (for example, a Wi-Fi AP), it is necessary to sequentially update the corresponding information in order to increase the cost.

Korean Patent Laid-Open No. 10-2011-0011546

An object of the present invention is to estimate a distance between wireless communication infrastructures that do not know the installation location by using wireless communication infrastructure measurement information received from a plurality of wireless communication infrastructures.

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

One embodiment of the present invention is a wireless communication system comprising: a receiving unit for receiving wireless communication infrastructure measurement information measured at a plurality of measurement points; An adjacent infrastructure determining unit determining adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information; A measurement point distance calculation unit for calculating measurement point distances from the respective measurement points using distances from adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information; An infrastructure distance estimator for estimating distances of infrastructures that are distances between the adjacent wireless communication infrastructures using the measurement point distances; And a storage unit for storing the information of the adjacent wireless communication infrastructures and the infrastructure distances, wherein the distance between the wireless communication infrastructures is unknown.

The infrastructure distance estimator may estimate the infrastructure distances so that the sum of the distance errors corresponding to each of the measurement point distances is minimum.

The apparatus for estimating the distance between wireless communication infrastructures unknown to the installation location may include a service providing unit for providing a location based service using the infrastructure distances using the infrastructure distance information.

Wherein the infrastructure distance estimator is configured to determine 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 a change amount of a measurement point distance that can occur according to a change in measurement information in a real environment , And estimate the infrastructure distances to minimize the sum of the distance errors.

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

According to another embodiment of the present invention, there is provided a wireless communication method comprising the steps of: receiving wireless communication infrastructure measurement information measured at a plurality of measurement points; Determining adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information; A measurement point distance calculation step of calculating, using the wireless communication infrastructure measurement information, measurement point distances that are distances from respective measurement points to adjacent wireless communication infrastructures; An infrastructure distance estimating step of estimating infrastructure distances, which are distances between the adjacent wireless communication infrastructures, using the measurement point distances; And a storage step of storing the information of the adjacent wireless communication infrastructures and the infrastructure distances, wherein the distance between the wireless communication infrastructures is unknown.

The infrastructure distance estimating step may estimate the infrastructure distances so that the sum of the distance errors corresponding to each of the measurement point distances is minimized.

The method for estimating the distance between wireless communication infrastructures that do not know the installation location may include providing a location based service using the infrastructure distances using the infrastructure distance information.

Wherein the infrastructure distance estimating step includes a step of estimating an infra-structure distance based on a condition that the infrastructure distances satisfy a triangular inequality in relation to the measurement points, and each of the distance errors is equal to or less than a change amount of a measurement point distance , It is possible to estimate the infrastructure distances to minimize the sum of the distance errors.

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

Yet another embodiment of the present invention provides a computer program stored on a medium for executing the method using a computer.

The present invention can estimate the distance between wireless communication infrastructures that do not know the installation location using the wireless communication infrastructure measurement information received from the 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 that do not know the installation location according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a method of estimating a distance between wireless communication infrastructures of unknown installation location according to an exemplary embodiment of the present invention. Referring to FIG.
3 is a diagram illustrating an example of measurement information of a plurality of wireless communication infrastructures measured through an arbitrary user terminal at any measurement point.
4 is a diagram illustrating an example of the location of some wireless communication infrastructures and measurement information of wireless communication infrastructures collected at various measurement points.
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.
Figure 6 is an illustration of several wireless communication infrastructures within a building, multiple measurement points, and examples of adjacent wireless communication infrastructures corresponding to respective measurement points.
7 is a diagram illustrating an example of a correlation DB according to distance information between a correlation DB and a wireless communication infrastructure according to a correlation between wireless communication infrastructures in the example shown in FIG.
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.
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.
10 illustrates a hop distribution from each wireless communication infrastructure to other wireless communication infrastructures in one example of an actual wireless communication environment by comparing the hop distribution using the correlations and the hop distribution using the infrastructure distances FIG.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. The effects and features of the present invention and methods of achieving them will be apparent with reference to the embodiments described in detail below with reference to the drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

However, the present invention is not limited to the embodiments described below, but all or some of the embodiments may be selectively combined and implemented in various forms. In the following embodiments, the terms first, second, and the like are used for the purpose of distinguishing one element from another element, not the limitative meaning. Also, the singular expressions include plural expressions unless the context clearly dictates otherwise. Also, the terms include, including, etc. mean that there is a feature, or element, recited in the specification and does not preclude the possibility that one or more other features or components may be added.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or corresponding components throughout the drawings, and a duplicate description thereof will be omitted .

FIG. 1 is a block diagram illustrating a configuration of an apparatus 100 for estimating a distance between wireless communication infrastructures that does not know the installation location according to an embodiment of the present invention.

Referring to FIG. 1, an apparatus 100 for estimating a distance between wireless communication infrastructures of unknown installation location according to an embodiment of the present invention includes a reception unit 110, an adjacent infrastructure determination unit 120, An infrastructure distance estimation unit 140, a storage unit 150, and the like.

The apparatus 100 for estimating the distance between wireless communication infrastructures that does not know the installation location according to an embodiment of the present invention includes a reception unit 110, an adjacent infrastructure determination unit 120, a measurement point distance calculation unit 130, An infrastructure distance estimation unit 140, a storage unit 150, a service providing unit 160, and the like.

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

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

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

The wireless communication infrastructure measurement information is transmitted from a device transmitting radio waves for wireless communication and positioning such as a mobile communication base station, Wi-Fi, Bluetooth (Bluetooth), Bluetooth low energy (BLE) It means the data measured when receiving. The received data includes an identifier, a transmitted radio wave intensity, a transmitted frequency, a Received Signal Strength Indicator (RSSI), a Round Trip Time (RTT), and an Angle of Arrival (AoA) And all the information that can be received in the standard data for each wireless communication infrastructure.

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

The neighbor infrastructure determining unit 120 determines the neighboring wireless communication infrastructures among the plurality of wireless communication infrastructures using the wireless communication infrastructure measurement information.

Herein, the adjacent wireless communication infrastructure means a wireless communication infrastructure spatially disposed close to each other. In the present invention, because the installation location information of the wireless communication infrastructure is unknown, It is judged that they are adjacent within the wireless communication signal reaching distance.

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

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

)을 계산할 수 있다. In addition, in an embodiment of the present invention, the measurement point distance calculation unit 130 may calculate 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 of the wireless communication infrastructure designed in accordance with the following equation (1) (Fris equation)

) And transmit / receive antenna gain (

,

).

[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 Reference Distance

) ≪ / RTI > is the receiver signal strength < RTI ID = 0.0 >

) And transmitter signal strength (

), And using Equation (1), the reference distance

), The wavelength of the designed wireless communication infrastructure (

) And transmit / receive antenna gain (

,

).

&Quot; (2) "

)은 하기 수학식 3과 같이 기준거리에서의 자유공간 경로손실(

), 경로 손실 지수(

), 측정지점거리(

) 및 기준거리(

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

) Is the free space path loss at the reference distance (

), Path loss index (

), Measuring point distance (

) And the reference distance (

).

&Quot; (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 (

(3), the free space path loss at the measurement point distance

), Free space path loss at the reference distance (

), Path loss index (

) And the reference distance (

). Also, the free space path loss at the measurement point distance ( ) Is the transmitter signal strength (

) And the receiver signal strength (

).

&Quot; (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 (

), Path loss index (

), Receiver signal strength (

). ≪ / RTI > At this time, the transmitter signal strength (

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

) Is the wavelength of the designed wireless communication infrastructure

), The reference distance (

), Transmit / receive antenna gain (

,

) Or the like. Pathloss Index (

) Can also be given in advance depending on the radio wave propagation environment.

)는 수신기 신호세기(

)만의 함수로 계산될 수 있으며, 수신전파세기만 측정되면 측정지점거리(

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

) Is the receiver signal strength (

), And when only the received radio wave intensity is measured, the measurement point distance (

) Can be calculated.

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

Also, in one embodiment of the present invention, the infrastructure distance estimator 140 may estimate the infrastructure distances such that the sum of the distance errors corresponding to the respective measurement point distances is minimized. Since the measurement point distance calculation unit 130 calculates the measurement point distance from the wireless communication infrastructure measurement information collected by the user's terminals, the distance between the actual measurement point and the target wireless communication infrastructure may be different from each other. Thus, estimating infrastructure distances where the sum of the distance errors, which is the error of the measurement point distances, is minimized, increases the likelihood of approaching the distance between the actual wireless communication infrastructures.

Also, in one embodiment of the present invention, the infrastructure distance estimating unit 140 may use linear programming to solve the problem of minimizing the sum of the distance errors. In particular, under the condition that the infrastructure distances satisfy the triangular inequality in relation to the measurement points and each of the distance errors is less than or equal to the variation of the measurement point distances that can occur in the real environment, It is possible to estimate the infrastructure distances so 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 is a wireless communication infrastructure m, a wireless communication infrastructure n, and N measurement points, the infrastructure distance (

) Must satisfy the triangular inequality of (5) for each measurement point. Also, distance errors (

,

(6) and (7), a variation amount of the measurement point distance (hereinafter referred to as " measurement point distance "

,

). Satisfies the following equations (5) to (7), the sum of the error distances

) To the minimum distance (

).

&Quot; (5) "

&Quot; (6) "

&Quot; (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 of the wireless communication infrastructure m and the measurement point k,

Is the calculated measurement point distance of the wireless communication infrastructure n and measurement point k,

The

Corresponding to the distance error,

The

Corresponding to the distance error,

The

A change amount of the measurement point distance corresponding to the measurement point distance,

The

A change amount of the measurement point distance corresponding to the measurement point distance,

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

In addition, in using the linear programming method, it is possible to add conditions according to the type of the wireless communication infrastructure and the structure of the measurement space.

The storage unit 150 stores information and infrastructure distances of adjacent wireless communication infrastructures. Herein, the information of the adjacent wireless communication infrastructures may include information of the adjacent wireless communication infrastructure set, information of the received radio wave intensity (RSSI), RTT, and AoA indicating the adjacent strengths of the wireless communication infrastructures and measurement points. Furthermore, information such as wireless communication infrastructure measurement information or measurement point distances collected at various measurement points can also be stored.

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

In the past, a location-based service based on a correlation between wireless communication infrastructures has been provided. However, 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 .

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

Referring to FIG. 2, a method 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 method of estimating a distance between wireless communication infrastructures (see 100 in FIG. 1) Receives the wireless communication infrastructure measurement information measured at a plurality of measurement points (S201).

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

The wireless communication infrastructure measurement information is transmitted from a device transmitting radio waves for wireless communication and positioning such as a mobile communication base station, Wi-Fi, Bluetooth (Bluetooth), Bluetooth low energy (BLE) It means the data measured when receiving. The received data includes an identifier, a transmitted radio wave intensity, a transmitted frequency, a Received Signal Strength Indicator (RSSI), a Round Trip Time (RTT), and an Angle of Arrival (AoA) And all the information that can be received in the standard data for each wireless communication infrastructure.

A method 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 method of estimating a distance between wireless communication infrastructures (see 100 in FIG. 1) The neighboring wireless communication infrastructures are determined using the infrastructure measurement information (S203).

Herein, the adjacent wireless communication infrastructure means a wireless communication infrastructure spatially disposed close to each other. In the present invention, because the installation location information of the wireless communication infrastructure is unknown, It is judged that they are adjacent within the wireless communication signal reaching distance.

A method 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 method of estimating a distance between wireless communication infrastructures (see 100 in FIG. 1) From the measurement points, measurement point distances to adjacent wireless communication infrastructures are calculated using the infrastructure measurement information (S205).

Here, the wireless communication infrastructure measurement information includes information such as a received radio wave intensity (RSSI), a round trip time (RTT) or a wave arrival angle (AoA), which implies a proximity strength between the terminal and the wireless communication infrastructures. This can be used to calculate 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. Further, the measurement point distances can be calculated through a free space path loss model using the received radio wave intensities. Measuring point distance (

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

), Free space path loss model at reference distance (

), Path loss index (

), Receiver signal strength (

). ≪ / RTI > At this time, the transmitter signal strength (

) Can be given in advance according to the transmitter specification and can be expressed in terms of the free space path loss model (

) Is the wavelength of the designed wireless communication infrastructure

), The reference distance (

), Transmit / receive antenna gain (

,

) Or the like. Pathloss Index (

) Can also be given in advance depending on the radio wave propagation environment.

)는 수신기 신호세기(

)만의 함수로 계산될 수 있으며, 수신전파세기만 측정되면 측정지점거리(

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

) Is the receiver signal strength (

), And when only the received radio wave intensity is measured, the measurement point distance (

) Can be calculated.

The method for estimating the distance between the wireless communication infrastructures that do not know the installation location according to an embodiment of the present invention includes the steps of estimating the distance between the wireless communication infrastructures (see 100 in FIG. 1) Distances between adjacent wireless communication infrastructures are estimated using the distances (S207).

At this time, the infrastructure distances may be estimated so that the sum of the distance errors corresponding to the respective measurement point distances calculated in step S205 is the minimum. Since the measurement point distance is calculated from the wireless communication infrastructure measurement information collected from the user's terminals, there may be a distance and an error between the actual measurement point and the target wireless communication infrastructure. Thus, estimating infrastructure distances where the sum of the distance errors, which is the error of the measurement point distances, is minimized, increases the likelihood of approaching the distance between the actual wireless communication infrastructures.

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

In addition, in using the linear programming method, it is possible to add conditions according to the type of the wireless communication infrastructure and the structure of the measurement space.

The method for estimating the distance between the wireless communication infrastructures which do not know the installation location according to the embodiment of the present invention is characterized in that the apparatus for estimating the distance between the wireless communication infrastructures (see 100 in FIG. 1) The information of the communication infrastructures and the distances of the infrastructures are stored (S209). Herein, the information of the adjacent wireless communication infrastructures may include information of the adjacent wireless communication infrastructure set, information of the received radio wave intensity (RSSI), RTT, and AoA indicating the adjacent strengths of the wireless communication infrastructures and measurement points.

Furthermore, information such as wireless communication infrastructure measurement information or measurement point distances collected at various measurement points can also be stored.

A method 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 method of estimating a distance between wireless communication infrastructures (see 100 in FIG. 1) Based service based on the shortest distance between the infrastructures (S211).

In the past, a location-based service based on a correlation between wireless communication infrastructures has been provided. However, 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 .

In an alternative embodiment, in steps S201, S203, S205, S207, S209, and S211, determining (S203) adjacent wireless communication infrastructures and calculating (S205) measuring point distances may be performed in parallel .

In an alternative embodiment, in step S201, S203, S205, S207, S209, and S211, the step of providing location-based services S211 includes storing information and infrastructure distances of adjacent wireless communication infrastructures S209 ).

In an alternative embodiment, in step S201, S203, S205, S207, S209, and S211, the step of providing location-based services S211 includes 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 any measurement point.

Referring to FIG. 3, assume for example that four Wi-Fi AP lists have been measured through any user terminal at any measurement point. In this case, four Wi-Fi APs (CCC, AAA, BBB, and EEE) are adjacent to each other within the Wi-Fi AP maximum radio wave propagation distance centering on the user terminal physically and the four Wi- Infrastructure.

FIG. 3 shows Wi-Fi APs and corresponding received radio wave strength (RSSI) information. The fact that the received radio wave intensity RSSI has a large value means that the user terminal is at a distance close to the corresponding wireless communication infrastructure.

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

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

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

4, it is assumed that (a) the distances from the Wi-Fi AP BBB and CCC to the arbitrary measuring point are the measuring point distances, (b) the distance between the Wi-Fi AP BBB and the CCC, to be.

The measurement point distances can be calculated through the information of the received radio wave intensity (RSSI), RTT, AoA, etc. included in the wireless communication infrastructure measurement information collected at each measurement point, and the infra distance can be calculated by summing the distance errors included in the measurement point distances Can be estimated and minimized.

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.

,

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

,

) 과의 차이인 오차거리(예:

,

)들이 포함되어 있다.Referring to FIG. 5, the measurement point distances (e.g., the distance from the measurement points) using the received radio wave intensity (RSSI) measured at AP m and AP n at each measurement point

,

), And the respective measurement point distances include the corresponding measurement points and the actual distances to the AP (e.g.,

,

(For example,

,

).

)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 distance between the AP m and the AP n

), It is possible to estimate the infra-structure distance by which the sum of the error distances is minimized by using the measurement point distances as the actual infrastructure distances. In other words,

Infrastructure distance that minimizes (

).

Figure 6 is an illustration of several wireless communication infrastructures within a building, multiple measurement points, and examples of adjacent wireless communication infrastructures corresponding to respective measurement points.

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 from measurement point 2 (user participation 2), AP AAA, CCC, DDD, and 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, 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, GGG constitute a set of adjacent wireless communication infrastructures; For AP HHH, there is no collected wireless communication infrastructure measurement information, so it does not constitute a set of adjacent wireless communication infrastructures.

It can be determined that the wireless communication infrastructures in the same set of adjacent wireless communication infrastructures are adjacent to each other, and the existing location-based services can be classified into a hierarchy through a correlation, such as how many adjacent wireless communication infrastructure sets pass between specific wireless communication infrastructures Based on number.

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

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

However, referring to the right part of FIG. 7, infrastructure distances instead of layers between each wireless communication infrastructure may be displayed in meters (m), to more accurately describe the actual proximity between the various wireless communication infrastructures. For example, in a correlation DB according to the hierarchy, the case where the AP DDD reaches to the AP EEE or the case where the AP DDD reaches the AP CCC corresponds to the layer 1 and has the same proximity; In the case of the correlation DB according to the infrastructure distance, the distance from the AP DDD to the AP EEE is 10 meters, and when the distance from the AP DDD to the AP CCC is 20 meters, the proximity is twice the difference.

Therefore, when using the correlation DB according to the correlation between the wireless communication infrastructures, the distance between the wireless communication infrastructures can not be directly estimated, and the correlation DB according to the distance information between the wireless communication infrastructures reflects the more accurate distribution situation of the wireless communication infrastructure , And 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.

The message sender may be a store owner who provides content such as coupons to nearby people using location based services and the message recipient may use location based services to provide content such as discount coupons for nearby stores And the like.

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

Therefore, 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 message receiver b corresponds to correlation 4 from the message sender, and the shortest distance between wireless communication infrastructures is 75 meters.

If the range of message transmission in the location-based service is divided into layers 1 to 5 on the basis of a correlation-related layer, message receiver a is able to receive from layer 1 to layer 5, and message receiver b It is possible to receive from layer 4 to layer 5.

If the range in which the message is transmitted by 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, Meters and 100 meters, and message receiver b is receivable only in the range of 100 meters.

The message receiver b can be determined that the correlation is 4 and relatively close even though the sum of the infrastructure distances from the sender of the message is 75 meters and relatively far away and the message receiver a can determine that the distance from the message sender is 15 meters It is judged that the correlation is 1 and it is judged that it is relatively close to 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 receiver can be provided with more accurate and reliable location-based services. However, if 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 the location-based service in which the 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.

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 assigned to AP FFF, the message receiver b to AP DDD, the message receiver c is AP GGG It is located closest to you.

Therefore, the message receiver a has a correlation of 2 from the message sender and the shortest distance between the wireless communication infrastructures is 40 meters. And message receiver b corresponds to correlation 1 from the message sender and the shortest distance between wireless communication infrastructures is 20 meters. And 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 layers 1 to 5 based on the correlation-related layer, message receiver a can receive from layer 2 to layer 5, 1 to layer 5 can be received. Also, message receiver c can receive from layer 3 to layer 5.

If the range in which a message is sent from a location-based service is divided into 10 meters, 30 meters, 50 meters, 70 meters and 100 meters based on distance information between wireless communication infrastructures, message receiver a is 50 meters, Meter, and message recipient b is receivable in the range of 30 meters, 50 meters, 70 meters and 100 meters. Also, the message receiver c is receivable in the range of 70 meters and 100 meters.

The message receiver a can be determined that the correlation is 2 and relatively close, even though the sum of the infrastructure distances from the message sender is 40 meters, and the message receiver b can determine that the distance from the message sender is 20 meters It is judged that the correlation is 1 and it is judged that it is relatively close to the message transmission range. Also, the message receiver c may be judged to be relatively close, since the correlation is 3, even though the sum of the infrastructure distances from the message sender is relatively long as 55 meters.

10 illustrates a hop distribution from each wireless communication infrastructure to other wireless communication infrastructures in one example of an actual wireless communication environment by comparing the hop distribution using the correlations and the hop distribution using the infrastructure distances FIG.

In particular, FIG. 10 shows a graph of the calculated shortest distance between target wireless communication infrastructures (e.g., Wi-Fi AP) in each identifiable wireless communication infrastructure (e.g., Wi-Fi AP) The comparison is made between the number of layers (left side) using correlation information and the number of layers using distance information (right side) without using distance information. The x-axis represents the ID of the wireless communication AP that is the starting reference for estimating the shortest distance, and the y-axis represents the distribution ratio of the number of layers of each target wireless communication infrastructures.

10, when it is assumed that the location-based service is provided for the target terminal within four layers of one building, the location-based service for the target terminal (for example, Discount coupon is provided). In other words, if the criteria that can be set for the location-based service is based on correlation, it can provide a very approximate and inaccurate location-based service because the service can only be provided by setting the layer to a value between 1 and 3 do.

On the other hand, when distance information is utilized, it is possible to provide a location-based service (for example, a discount coupon provided) segmented within 6 layers by reflecting the estimated distance information between layers. In particular, since it is possible to set a distance reference (for example, 50 m) commonly used in existing location-based services, it is possible to more accurately trigger and provide a customized location-based service to a target terminal.

Especially, since it is possible to determine the location based service range by using the distance information, it is highly compatible with the previously designed location based service, and the setting standard is intuitive and clear.

Also, as the wireless communication infrastructure measurement information accumulates, the estimated distance information between the wireless communication infrastructures can be more accurate. If the wireless communication infrastructure is previously installed or removed, There is also an advantage that information can be utilized and updated.

First of all, it is possible to accumulate a plurality of wireless communication infrastructure measurement information provided by a user terminal without initial acquisition in an indoor environment and estimate a correlation DB and distance information between the wireless communication infrastructures based on the accumulated measurement information, thereby providing a location based service in the corresponding indoor environment Is a great contribution of the present invention.

Meanwhile, the method for estimating the distance between the wireless communication infrastructures that do not know the installation location may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable recording medium. At this time, the computer-readable recording medium may include a program command, a data file, a data structure, or the like, alone or in combination. On the other hand, the program instructions recorded on the recording medium may be those specially designed and configured for the present invention or may be available to those skilled in the art of computer software.

The computer-readable recording medium includes a magnetic recording medium such as a magnetic medium such as a hard disk, a floppy disk and a magnetic tape, an optical medium such as a CD-ROM and a DVD, a magnetic disk such as a floppy disk, A magneto-optical media, and a hardware device specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. The recording medium may be a transmission medium, such as a light or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a data structure, and the like.

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

110: a device for estimating the distance between wireless communication infrastructures unknown to the installation location
110: Receiving unit 120: Neighboring infrastructure determining unit
130: measurement point distance calculation unit 140:
150: storage unit 160:

Claims (1)

A receiving unit for receiving wireless communication infrastructure measurement information measured at a plurality of measurement points;
An adjacent infrastructure determining unit determining adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information;
A measurement point distance calculation unit for calculating measurement point distances from the respective measurement points using distances from adjacent wireless communication infrastructures using the wireless communication infrastructure measurement information;
An infrastructure distance estimator for estimating distances of infrastructures that are distances between the adjacent wireless communication infrastructures using the measurement point distances; And
And a storage for storing the information of the adjacent wireless communication infrastructures and the infrastructure distances, wherein the distance between the wireless communication infrastructures is unknown.

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