KR20210144375A - Method for positioning of mobile terminal - Google Patents

Abstract

Provided is a method for determining the location of a mobile terminal to determine the location of the terminal in consideration of different transmission distance losses according to a base station frequency. According to the present invention, the method comprises the following steps: receiving, by a terminal, at least one base station information received from at least one base station adjacent to the terminal; detecting a base station identifier, a base station frequency, and a received signal strength from the at least one base station information and identifying a base station location corresponding to the base station identifier from a base station database; and when the at least one base station identifier is detected in at least two different base station frequencies, applying, to the location of the base station, at least one of a path-loss model between base stations using different frequencies, an Apollonius circle generated by using location coordinates of the base stations and the received signal strength, and a transmission distance ratio on the basis of the received signal strength of the base stations to estimate the location of the terminal.

Description

How to determine the position of the terminal {METHOD FOR POSITIONING OF MOBILE TERMINAL

The present invention relates to a method for determining a location of a terminal, and to a method and an apparatus for determining a location of a terminal based on base station information received from at least one base station by the terminal.

When a Global Positioning System (GPS) module capable of confirming a reference time is installed in each base station, it is common to improve positioning accuracy by using a Time Difference of Arrival (TDoA) method.

However, due to the nature of the network configuration, when a repeater is used or a GPS module for checking the reference time is not attached to each base station, it is impossible to measure the required time from the base station except for the serving cell. Therefore, it is impossible to utilize the TDoA method.

In this case, in the case of the current ECID (Enhanced Cell-ID) based positioning method, the location of a single base station is used by utilizing the received signal strength, for example, Reference Signal Received Power (RSRP), Received Signal Strength Indicator (RSSI), etc. Therefore, instead of estimating the location of the terminal, a method of estimating the location of the terminal by reflecting the loss according to the transmission distance from the location of at least three base stations is selected.

However, the frequency band used by each communication service provider is different, and the frequency band of the base station installed by each communication service provider is also different from each other.

Since the center frequency and the bandwidth are different for each frequency band, the loss according to the transmission distance of the signal received by the terminal from each base station is different even in the same channel environment.

Since it does not reflect the directivity and tilting angle of the antenna set in advance for communication performance optimization, it shows an error of about 100m even in downtown areas. Therefore, it is necessary to improve the positioning accuracy in order to use it in real life.

An object of the present invention is to provide a method for determining a location of a terminal in consideration of different transmission distance losses according to base station frequencies.

According to one feature of the present invention, there is provided a method for a positioning device to determine a location of a terminal, the method comprising: receiving, by the terminal, a plurality of base station information received from a plurality of base stations adjacent to the terminal from the terminal; Detecting a base station identifier, a base station frequency, and a received signal strength from the information, respectively, confirming a base station location corresponding to each base station identifier from a base station database, and corresponding to the base station identifiers respectively detected at at least two different base station frequencies estimating the location of the terminal using the base station locations and the detected received signal strengths, wherein the estimating comprises a path-loss model between base stations using different frequencies, or the The location of the terminal is estimated by applying a transmission distance ratio according to the received signal strength of each of the base stations to the location of each of the base stations.

After the estimating step, the method may further include correcting the estimated location of the terminal by reflecting the antenna gain values of each of the base stations used in estimating the location of the terminal.

The step of correcting may include checking the antenna gain values of each of the base stations, selecting a first base station as a reference based on the antenna gain values, and a second base station based on a difference between the first base station and the antenna gain values. Selecting a base station and a third base station, estimating the transmission distance between the estimated position of the terminal and the second base station using the antenna gain value and the received signal strength of the second base station, and installing the antenna of the second base station Checking a direction, calculating a first vector composed of the transmission distance and the installation direction; Transmission between the estimated location of the terminal and the third base station using the antenna gain value of the third base station and the received signal strength estimating the distance, confirming the antenna installation direction of the third base station, calculating a second vector composed of the transmission distance and the installation direction, and the first vector and the second vector are summed It may include moving the estimated location of the terminal and determining the moved location as the location of the terminal.

After the step of calibrating, repeating the step of calibrating using the changed antenna gain value of each base station generated at the moved position, and there is no change in the corrected position calculated through repetition or the amount of change is within the critical region In the case of convergence, the method may further include determining the arithmetic mean value of the corrected positions calculated so far as the final position of the terminal.

In the estimating of the location of the terminal, when one base station identifier is detected at at least two different base station frequencies, the location of the terminal by applying a path-loss model to the base station location corresponding to each base station identifier can be estimated.

In the step of estimating the location of the terminal, when two base station identifiers are detected at at least two different base station frequencies, the intersection point or the nearest point between Apollonius circles respectively generated around the base station location corresponding to each base station identifier can be used to estimate the location of the terminal.

In the estimating of the location of the terminal, when at least three base station identifiers are detected at at least two different base station frequencies and at least two base station identifiers are detected at at least two different base station frequencies, the at least three base station identifiers Estimating the arithmetic average of the first position calculated using each base station position corresponding to and the second position calculated using each position corresponding to the at least two base station identifiers as the terminal position, the first position is estimated using a transmission distance ratio according to the received signal strength received from each base station with respect to the base station location corresponding to the at least three base station identifiers, and the second location corresponds to the at least two base station identifiers. It may be an intersection point or a nearest point between Apollonius circles respectively generated with respect to the base station location.

In the estimating of the location of the terminal, at least three base station identifiers are detected at at least two different base station frequencies, at least one base station identifier is detected at at least one different base station frequency, and at least one different base station frequency is detected. In the first case in which up to two base station identifiers are detected, or in the second case in which at least three base station identifiers are detected at at least three different base station frequencies, each base station centered on the base station location corresponding to the at least three base station identifiers A transmission distance ratio according to the received signal strength may be used.

In the estimating of the location of the terminal, when at least three base station identifiers are detected at a first base station frequency and a maximum of two base station identifiers are detected at at least one second base station frequency different from the first base station frequency, the using an arithmetic mean value between a first position estimated from a base station position corresponding to at least three base station identifiers and a second position estimated from a base station position corresponding to a base station identifier detected at the second base station frequency, wherein the first position is , using the transmission distance ratio according to the received signal strength received from each base station with respect to the base station location corresponding to the at least three base station identifiers, and the second location may use the transmission distance ratio or the path loss model. .

According to another feature of the present invention, there is provided a method for a positioning device to determine a location of a terminal, the method comprising: receiving information about a base station adjacent to the terminal from the terminal; based on the received information, a base station adjacent to the terminal Determining whether there are at least two base stations and each base station uses different frequencies, and when one base station using at least two different base station frequencies is detected, applying a path-loss model to the detected base station location estimating the location of the terminal, when two base stations using at least two different base station frequencies are detected, respectively, the intersection or nearest point between Apollonius circles generated based on the received signal strength based on the location of each base station Estimating the position of the terminal using a point, and when the number of base stations using at least two different base station frequencies is detected differently at each base station frequency, estimating from the base station location detected at at least one first base station frequency and estimating the location of the terminal using an arithmetic mean value between the first location and the second location estimated from the base station location detected at at least one second base station frequency.

After the step of estimating the location of the terminal, if there are at least three base stations used in determining the location of the terminal, the azimuth angle of each base station using the estimated location of the terminal and the location of each base station used in estimating the location of the terminal The method may further include checking a vector and a vector, and correcting the estimated position of the terminal based on the antenna gain for each base station identified using the azimuth.

The first location and the second location are the path loss model, the intersection or nearest point between the Apollonius circles, the transmission distance ratio according to the received signal strength received from each base station around the location of each base station, and the base station connecting the base station It may be estimated using at least one of the internal division points of the line segment.

According to an embodiment, positioning accuracy can be improved compared to an ECID (enhanced cell ID)-based positioning method that indicates the location of an existing serving cell.

In addition, it is possible to implement a technique for estimating the location more accurately without requesting additional information from the terminal. Therefore, in the short term, it is possible to gain a comparative advantage over competitors by improving the quality evaluation performance of the Korea Communications Commission. New business creation may be possible.

In addition, by improving the positioning accuracy for the positioning solution, the activation of location-based services can be expected.

1 is a configuration diagram of a positioning network according to an embodiment of the present invention.
2 is a flowchart illustrating a terminal location determination process according to an embodiment of the present invention.
3 is a flowchart illustrating a process of estimating a terminal location when PCI is detected at a single frequency according to an embodiment of the present invention.
FIG. 4 is a view for explaining step S209 of FIG. 3 .
FIG. 5 is a view for explaining step S211 of FIG. 3 .
FIG. 6 is a view for explaining step S215 of FIG. 3 .
7 is a diagram for explaining a method of estimating a terminal location when PCI is detected at multiple frequencies according to an embodiment of the present invention.
8 is a diagram for explaining a method of estimating a terminal location when PCI is detected at multiple frequencies according to another embodiment of the present invention.
9 is a diagram for explaining a method of estimating a terminal location when PCI is detected at multiple frequencies according to another embodiment of the present invention.
10 is a diagram for explaining a method of estimating a terminal location when PCI is detected at multiple frequencies according to another embodiment of the present invention.
11 is a view for explaining a terminal position correction method according to an embodiment of the present invention.
12 is a flowchart illustrating the method of FIG. 11 .
13 is a view for explaining a terminal position correction method according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

In addition, terms such as “…unit”, “…group”, and “…module” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. can

The devices described in the present invention are composed of hardware including at least one processor, a memory device, a communication device, and the like, and a program executed in combination with the hardware is stored in a designated place. The hardware has the configuration and capability to implement the method of the present invention. The program includes instructions for implementing the method of operation of the present invention described with reference to the drawings, and is combined with hardware such as a processor and a memory device to execute the present invention.

As used herein, "transmission or provision" may include not only direct transmission or provision, but also transmission or provision indirectly through another device or using a detour path.

In the present specification, expressions described in the singular may be construed in the singular or plural unless an explicit expression such as “a” or “single” is used.

In this specification, the same reference numbers refer to the same components regardless of the drawings, and "and/or" includes each and every combination of one or more of the referenced components.

In this specification, terms including an ordinal number such as first, second, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present disclosure, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

In the flowchart described with reference to the drawings in this specification, the order of operations may be changed, several operations may be merged, some operations may be divided, and specific operations may not be performed.

In the present specification, a terminal is a generic concept meaning a user terminal in communication, and is a user equipment (UE), a mobile station (MS), a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), and an AT ( Access Terminal), mobile station, mobile terminal, subscriber station, portable subscriber station, user equipment, access terminal, wireless device, etc. It may include all or part of the functions of a home country, a portable subscriber station, a user equipment, an access terminal, a wireless device, and the like.

A terminal is a base station (BS), an access point (Access Point, AP), a radio access station (RAS), a Node B (Node B), an advanced Node B (evolved NodeB, eNodeB), a transmission and reception base station ( It can be connected to a remote server by accessing a network device such as a Base Transceiver Station (BTS) or Mobile Multihop Relay (MMR)-BS.

Base Station (BS) is an Access Point (AP), Radio Access Station (RAS), Node B (Node B), Base Transceiver Station (BTS), MMR (Mobile Multihop Relay) )-BS, etc. may refer to, and may include all or some functions of an access point, a radio access station, a Node B, a transceiver base station, an MMR-BS, and the like.

The terminal of the present specification is a communication terminal of various types, such as a mobile terminal such as a smart phone, a tablet terminal such as a smart pad and a tablet PC, a computer, and a television, and may include a plurality of communication interfaces.

Embodiments of the present invention are 3GPP (3rd Generation Partnership Project) Long Term Evolution (LTE), LTE-A, 3GPP2, IEEE (Institute of Electrical and Electronics Engineers) system, 3GPP such as FS_NextGen (Study on Architecture for Next Generation System). It may be supported by standard documents related to at least one of the 5G systems. That is, steps or parts not described in order to clearly reveal the technical spirit of the present invention among the embodiments of the present invention may be supported by the document. In addition, all terms disclosed in this document may be explained by the standard document.

In LTE Release 9 or LTE-A (Release 10), a location position protocol (hereinafter, collectively referred to as 'LPP') has been introduced. LPP is largely divided into three functions: A-GNSS (Assisted Global Navigation Satellite System), OTDOA (Observed Time Differential Of Arrival), and E-CID (Enhanced Cell ID) method. An embodiment of the present invention uses E-CID technology.

Now, a method for determining a location of a terminal according to an embodiment of the present invention will be described with reference to the drawings.

1 is a configuration diagram of a positioning network according to an embodiment of the present invention.

Referring to FIG. 1 , the terminal 100 communicates with a plurality of base stations C1 , C2 , and C3 while exchanging unique identification information.

A plurality of base stations (C1, C2, C3) transmits a radio frequency (RF) signal for providing a mobile communication service to the terminal 100 within the service area of the cell unit managed by the base station.

The plurality of base stations C1, C2, and C3 have different frequency bands to minimize interference. Since each frequency band has a different center frequency and bandwidth, the strength of a signal received by the terminal 100 is different even in the same channel environment. In the case of telecommunication operators, the bands mainly used are different depending on the region.

The positioning apparatus 200 determines the position of the terminal 100 in relation to the plurality of base stations C1, C2, and C3.

The terminal 100 also periodically scans base station information on other base stations C2 and C3 adjacent to the terminal 100 in addition to the connected base station C1 in order to maintain stable communication quality and transmits it to the positioning device 200. .

The terminal 100 periodically transmits the base station information received from each of the base stations C1, C2, and C3 to the positioning device 200 or transmits the base station information to the positioning device 200 when there is a user's request or a request from a third party. send.

In the LPP model, the terminal 100 uses base stations C1, C2, and C3 and a reference signal of a satellite (which may be variously referred to as a pilot signal or a preamble) for positioning.

The terminal 100 generates measurement information or location information from the reference signals received from the base stations C1, C2, and C3 and transmits it to the positioning device 200, and the final positioning is determined This is done in device 200 .

According to the LPP model, base station information may be referred to as measurement information or positioning information, but in the detailed description of the present invention, it is described as base station information.

Here, the base station information may include a frequency band of each base station C1, C2, and C3, a base station identifier, received signal strength, and the like.

The frequency band may include an E-UTRA Absolute Radio Frequency Channel Number (EARFCN), which is a parameter indicating radio frequency channel information.

The base station identifier may include at least one of cell ID (Cell ID, CID), RU (Radio Unit)-ID, PCI (Physical Cell Identity), and TA (Tracking Area) information. In the embodiment of the present invention, it will be described using PCI.

The received signal strength may include reference signal received power (RSRP).

The positioning apparatus 200 determines the location of the terminal 100 based on the base station information received from the terminal 100 , and transmits the determined location information to the terminal 100 .

In an urban area where base stations are densely arranged, a relatively large amount of neighbor cell information is provided, and in a non-urban area, since the physical distance between base stations is long, there is relatively little information on neighboring cells that can be checked by the terminal.

In the case of downtown, it is common to install base stations having different frequencies to minimize interference and the like, and in general, frequencies are distinguished through channel information. Since each frequency has a different center frequency and bandwidth, the strength of a signal received by the terminal 100 is different even in the same channel environment. The positioning accuracy can be improved only when positioning is performed reflecting this. Since the center frequency and the bandwidth used for communication are different for each frequency band of a telecommunication service provider, even if equipment having the same characteristics is used in the same environment, the loss according to the transmission distance is different. Therefore, different models must be applied to estimate the transmission distance or transmission distance ratio based on RSRP. Until now, the location was estimated based on the received base station information without distinction of EARFCN.

Accordingly, in the embodiment of the present invention, the positioning device 200 divides the base station signal received by the terminal 100 into a plurality of (n) bands used by the communication service provider using the EARFCN. Then, the position of the terminal 100 is estimated by checking the number of PCIs received for each frequency.

Hereinafter, the base station identifier is described as PCI for convenience of description, but is not limited thereto.

2 is a flowchart illustrating a terminal location determination process according to an embodiment of the present invention.

Referring to FIG. 2 , the positioning apparatus 200 receives at least one information about a base station to which the terminal 100 is connected and adjacent to the terminal 100 from the terminal 100 ( S101 ).

The positioning device 200 obtains a base station identifier (PCI), a base station frequency (EARFCN), and a received signal strength (RSRP) from at least one base station information received in step S101, respectively (S103).

The positioning device 200 determines whether at least two different frequencies are obtained in step S103 (S105). That is, it is determined whether the base station to which the terminal 100 is connected and the base station adjacent to the terminal 100 use at least two different frequencies (S105).

If it is determined that only the same frequency is used in step S105, that is, when PCI is collected only at the same frequency, the positioning device 200 checks the number of PCIs acquired in step S103, and uses the positioning method defined for each number of PCIs. Estimate the location of the terminal (S107).

If it is determined that the PCI is collected at at least two different frequencies in step S105 (S105), the positioning device 200 integrates the calculated position values in consideration of the number of PCIs collected for each frequency to set the position of the terminal 100. The position is estimated (S109). That is, when there are at least two or more frequency bands in which at least one PCI is detected, the positioning device 200 performs positioning in a defined manner by combining the detected number of PCIs and the detected frequency bands (S109). The positioning apparatus 200 estimates the terminal location by applying at least one of a path-loss model, a distance ratio between base stations based on received signal strength information, and an arithmetic average to a method defined in the number of base station identifiers. (S109).

After step S107 and/or step S109, the positioning apparatus 200 determines whether information about at least three base stations is reflected when determining the location of the terminal (S111).

The positioning apparatus 200 corrects the terminal position determined in step S107 and/or step S109 by using the antenna gain of each base station when at least three base station information is reflected when determining the terminal location, and sets the corrected terminal location to the final terminal location is determined (S113).

The positioning apparatus 200 checks the azimuth and vector of each base station by using the location of the terminal 100 and the location of each base station used in determining the location of the terminal 100 . In addition, the positioning apparatus 200 may correct the position of the terminal by using the antenna gain calculated from the antenna pattern for each base station. At this time, information about the antenna pattern/antenna gain for each base station and the base station location coordinates are pre-formed into DB.

On the other hand, if it is determined that two or less base station information is used in step S111, the terminal location estimated in step S107 or step S109 is determined as the final terminal location (S115).

Steps S107 and S109 will be described in detail.

3 is a flowchart illustrating a process of estimating a terminal location when PCI is detected at a single frequency according to an embodiment of the present invention, FIG. 4 is a diagram illustrating step S209 of FIG. 3, and FIG. 5 is a diagram of FIG. It is a diagram for explaining step S211, FIG. 6 is a diagram for explaining step S215 of FIG. 3, and FIG. 7 is a diagram for explaining a method of estimating a terminal location when PCI is detected at multiple frequencies according to an embodiment of the present invention 8 is a diagram for explaining a method of estimating a terminal location when PCI is detected at multiple frequencies according to another embodiment of the present invention, and FIG. It is a diagram for explaining a method of estimating a terminal location when PCI is detected, and FIG. 10 is a diagram for explaining a method for estimating a terminal location when PCI is detected at multiple frequencies according to another embodiment of the present invention.

First, the method of estimating the location of the terminal 100 in steps S107 and S109 is described by taking the case where the terminal 100 receives base station information from base stations having four different frequencies as an example, the following table It can be arranged as 1.

Case Number of PCIs per frequency Primary terminal location estimation method frequency 1 frequency 2 frequency 3 frequency 4 One One 0 0 0 The location information of the base station corresponding to the PCI collected at frequency 1 (same as the method of using CID) 2 2 0 0 0 Integrity point between RSRP-based base stations 3 3+ 0 0 0 Position estimation using the initial overlap area or distance ratio according to the increase in unit circle radius 4 One One 0 0 Based on the path-loss model
divergence between base stations 5 One One A B (However, A≤1, B≤2, A+B >1)
Path-loss model-based location estimation 6 2 2 A B (However, A≤2, B≤2)
Point of intersection or nearest point between Apollonius circles 7 3+ 3+ A B (However, A≤1, B≤2)
Arithmetic mean between three or more PCI estimated points 8 3+ 3+ 2 2 Arithmetic mean between points estimated by 3 or more PCI and points estimated by Apollonius circle set of [2, 2] 9 3+ 3+ 3+ A or 3+ (However, A≤2)
Arithmetic mean between three or more PCI estimated points 10 3+ A B C (However, when A≤2, B≤2, C≤2 and A+B+C≥2)
Arithmetic mean between points estimated by 3 or more PCI and points estimated by combinations of [A, B, C]

Referring to Table 1, Cases 1, 2, and 3 are cases in which PCI is detected only within a single frequency, and will be described with reference to FIGS. 3, 4 and 5 as follows.

First, referring to FIG. 3 , the positioning device 200 checks the number of PCIs ( i ) collected within the same frequency ( S201 ).

If it is determined that i ≥ 3 (S203), the positioning device 200 generates circles using the positions of the base station corresponding to each PCI and the distance ratio according to the RSRP (S205).

The positioning device 200 determines whether an overlapping region of circles exists (S207).

If it is determined in step S207 that the overlapping area of the circles exists, the positioning apparatus 200 calculates the center coordinates of the initial overlapping area of the circles, and estimates the center coordinates as the location of the terminal 100 ( S209 ).

Referring to FIG. 4 , the positioning device 200 generates a circle based on the position coordinates of each base station when each base station corresponding to the collected PCI is C1, C2, and C3. At this time, the radius of each circle is set using the RSRP received from each base station.

Specifically, the positioning device 200 sets the distance increase coefficient per 6 dBm to double based on the highest RSRP (dBm). For example, the positioning device 200 has a C1 RSRP of -60 dBm, a C2 RSRP of -66 dBm, and a C3 RSRP of -78 dBm. (=2 ¹ ), and the base station with a difference of -18dBm from C1 sets the coefficient to 8 (=2 ³ ).

The positioning device 200 generates a circle having a reference radius r1 based on the location coordinate of C1. Here, the reference distance may be calculated according to a predetermined method based on the density of base stations or the distance between the base stations C1, C2, and C3 in an area including the location coordinates of C1, C2, and C3. For example, the positioning device 200 sets the reference distance to 1 m in the case of a downtown area where the base stations are densely arranged, and sets the reference distance to 10 m in the case of an outlying area far from the city center. can be set to

The positioning device 200 generates a circle having a reference radius r2 based on the location coordinates of C2. The positioning device 200 generates a circle having a reference radius r3 based on the location coordinate of C3. At this time, r2 is set to 2 times r1, and r3 is set to 8 times r1.

As such, the positioning device 200 generates an RSRP-based circle each having a radius of a distance reflected by a coefficient while sequentially increasing a reference distance based on the coordinates of each base station location.

In the region where all three different circles are first overlapped (hatched), three overlapping coordinates (i1, i2, i3) are detected, and the arithmetic mean value of the overlapping coordinates (i1, i2, i3) is the center coordinate of the terminal position ( u) is estimated (S209).

However, the three circles may not overlap. That is, if it is determined that there is no overlapping area in step S207, the terminal location is estimated using the transmission distance ratio based on RSRP (S211). For example, if the area where all three or more circles overlap first exists on a straight line connecting the base station, the positioning device 200 estimates the distance ratio based on RSRP and then estimates the location using the formula .

Referring to Figure 5, C1, C2, C3 a total of three PCIs are detected, the RSRP of C1 is -70dBm, the RSRP of C2 is -76dBm, and the RSRP of C3 is -82dBm, the distance ratio based on RSRP is α:β Assume :γ. In this case, the terminal location u can be obtained as in Equation 1 below.

Here, the position coordinates of C1 = (X ₁ , Y ₁ ), the position coordinates of C2 = (X ₂ , Y ₂ ), and the position coordinates of C3 = (X ₃ , Y ₃ ). A, B, and C are distance ratio coefficients calculated based on the respective distance ratios α, β, and γ, and are calculated as in Equation (2).

Again, referring to FIG. 3, if it is determined that i = 2 (S213), the positioning device 200, as shown in FIG. 6, coordinates and signal strength (RSRP) for each base station corresponding to the PCI An internal branch point is generated based on the ratio, and the internal branch point is estimated as the location of the terminal 100 (S215). That is, the positioning device 200 calculates the distance ratio based on the RSRP, and generates a circle of Apollonius that satisfies the corresponding condition.

In addition, if it is determined that i = 1 (S217), the positioning apparatus 200 estimates the location of the base station, which is uniquely collected in the same way as the existing CID, as the location of the terminal (S219).

Also, if the PCI is not detected, the positioning device 200 processes it as a terminal position estimation failure.

Referring to Table 1, when there is no frequency in which three or more PCIs are detected as in Case 4, an internal branch point between base stations to which a path-loss model of 3GPP is applied is determined as a terminal location.

Referring to Figure 7, C1 and C2 have different frequencies, but RSRP is the same as = -70 dBm. When the path loss model according to the respective center frequencies and bandwidths of C1 and C2 is applied, the positioning device 200 determines an internal branch point having a different distance ratio (α≠β) as the terminal location (u). The path loss model means that the communication signal is attenuated as the distance from the point of origin increases. Unlike in free space, path loss in the city center is affected by factors such as buildings and topographical features. The path loss model is obtained by using information such as GIS information and frequency of a specific area in order to understand the characteristics of radio waves before the base station is installed, and is information stored in advance.

The method of estimating the position of the terminal using the location coordinates of the two base stations, the RSRP received from each base station, and the path loss model by the positioning device 200 uses the position estimation technique of the known path loss model, and detailed description is omitted. .

In case 5, at least four different frequencies are detected. In frequency 1 and frequency 2, one PCI is detected, and in frequency 3 and frequency 4, the sum of the detected PCIs is greater than 1. applies to The positioning device 200 estimates the terminal position by applying the distance ratio estimated based on the RSRP collected from the base station corresponding to each PCI to Equations 1 and 2.

Referring to FIG. 8 , Case 5 is a method combining Case 3 and Case 4, and the positioning device 200 applies a path loss model when estimating the distance ratio, and applies the estimated distance ratio to Case 3 to the terminal. Estimate the position (u). If this is expressed as an equation, it is as Equation 3.

Here, the location coordinates of C1=(X ₁ , Y ₁ ), the location coordinates of C2=(X ₂ , Y ₂ ), the location coordinates of C3=(X ₃ , Y ₃ ), the location coordinates of C4=(X ₄ , Y ₄ ). The distance ratio is C1:C2:C3:C4=α:β:γ:δ.

In Case 6, two PCIs are detected and at least two frequencies are detected, and the positioning device 200 derives coordinates by using the intersection point between Apollonius circles.

For convenience of description, a case in which two PCIs are detected at frequency 1 and frequency 2 will be described as an example. At this time, the base stations corresponding to the PCI of frequency 1 are C1 and C2, respectively, and the base stations corresponding to the PCI of the frequency 2 are C3 and C4, respectively.

Referring to FIG. 9 , the positioning device 200 generates an Apollonius circle P1 having a line segment connecting the inner and outer division points of C1 and C2 as a diameter, and Apollonius having a line segment connecting the inner and outer division points of C3 and C4 as a diameter. Create a circle P3. At this time, the inner and outer points of each Apollonius circle (P1, P3) are set by applying the distance ratio to which the path loss model according to RSRP of each base station (C1, C2, C3, C4) is applied.

The positioning device 200 estimates the coordinates of the center of the area (point mark) in which the Apollonius circles P1 and P3 overlap as the terminal position u. The positioning device 200 calculates the center coordinates through the arithmetic mean of the intersection points i1 and i2 of the overlapping area.

If there is no overlapping region, the positioning device 200 estimates the midpoint of a straight line connecting the shortest distance between the Apollonius circles P1 and P3 as the terminal position u.

In addition, when two PCIs are detected in frequency 1 and frequency 2, respectively, and at least one PCI is detected in at least one frequency different from these, the positioning device 200 is at least one other frequency except for frequencies 1 and 2. For example, Case 4 or Case 5 is applied to estimate the terminal location. Then, an intersection point (i1 or i2) of the closest overlapping area with the estimated terminal location is estimated as the terminal location.

In the case of Case 7 and Case 9, the positioning device 200 estimates the position of each terminal in the same manner as in Case 3 for each frequency at which at least three PCIs are detected, and calculates the arithmetic mean value of the estimated terminal position as the terminal position (u) decide with

At this time, for convenience of explanation, a case in which at least three PCIs are detected at frequency 1 and frequency 2 is described as shown in FIG. 10 .

Referring to FIG. 10 , respective base stations corresponding to PCIs at frequency 1 are C1, C2, and C3, and respective base stations corresponding to PCIs at frequency 2 are C4, C5, and C6.

If the position of the terminal calculated by applying the method of Case 3 with respect to frequency 1 is u _A and the position of the terminal calculated by applying the method of Case 3 with respect to frequency 2 is u _B , the positioning device 200 is u _A and The arithmetic mean value of u _B is determined as the terminal location.

Case 8 corresponds to a case where the circle of Apollonius can be created. At this time, the positioning device 200 estimates _{two candidate terminal positions (u A} , u _B ) using Case 3 for at least three PCI detected frequencies. And the positioning device 200 estimates _{one candidate terminal position (u c} ) using Case 6 for frequencies at which two PCIs are detected, respectively. The positioning apparatus 200 estimates the arithmetic mean value of the _{candidate terminal positions u A} , u _B , u _{c as the terminal position u.}

In Case 10, at least three PCIs are detected and only one frequency is detected, and unlike Case 8, it is not possible to generate an Apollonius circle. In case 10, the terminal location is estimated by combining Case 3 and Case 5.

The positioning device 200 estimates _{the candidate terminal location (u A} ) using Case 3 with respect to the frequency at which at least three PCIs are detected. _{And the candidate terminal position (u B} ) is estimated using the base station coordinates corresponding to the PCI detected in the remaining frequencies except for at least three detected frequencies and using the distance ratio of RSRP according to the path loss model. The positioning apparatus 200 estimates the arithmetic mean value of the _{candidate terminal positions u A} and u _{B as the terminal position u.}

The positioning device 200 is the same as a single frequency estimated by three or more PCIs when a single estimated value can be secured through a combination between the frequencies (excluding the internal distribution point) when there are multiple frequencies composed of less than three PCIs. By weighting, the terminal position can be estimated using the arithmetic mean value.

In addition, if the case where i (number of PCI) = 2 for each frequency is included among the cases described above, the positioning device 200 does not limit the internal branch point to the terminal location, and sets the area of the candidate terminal location according to the surrounding environment. have. For example, in the case of an urban environment, since there is a relatively high probability of receiving information about other base stations within a nearby area, the semicircle area of Apollonius, which is the area between the two base stations, among the entire area of the Apollonius circle created using the positions of the two base stations. can be set by limiting the area of the candidate terminal location. On the other hand, since there are not many base stations per se in the case of an outlying area, the entire Apollonius circle can be estimated as the area of the candidate terminal location. This gives priority to the divergence point between the two base stations because, if it is an urban area, there is a relatively high possibility that additional base stations exist outside the Apollonius circle. In the case of an outlying area, since there are not many base stations themselves, no additional weight is given to the inner distribution point.

In this way, the estimated location of the terminal does not reflect the characteristics of the base station, and is a value estimated only with the RSRP and the location of the base station. However, since RSRP is affected by the characteristics of the antenna transmitting the signal, the terminal position may be corrected by reflecting the gain value according to the antenna angle.

In cases other than Cases 1, 2, and 4, information on at least three base stations was reflected when estimating the location of the terminal. The RSRP value of PCI used for double actual positioning or correction is a case in which the transmit signal strength itself in a specific direction is different depending on the antenna pattern. Accordingly, the azimuth and vector between the position of the terminal and the position of the base station can be confirmed.

The positioning apparatus 200 determines the azimuth and vector of each base station using the positions of each base station when at least three base station locations are used in estimating the location of the terminal, and uses the antenna gain estimated from the antenna pattern for each base station to the terminal correct the position of

If it is necessary to move the terminal position from the estimated direction angle, the movement size is determined through the following process. This will be described as follows.

11 is a diagram illustrating a terminal position correction method according to an embodiment of the present invention, and FIG. 12 is a flowchart illustrating the method of FIG. 11 . At this time, for convenience of description, it is assumed that three base stations are used. The positioning device 200 corrects the terminal position in the direction of the reference base station.

Referring to FIG. 11 , A indicates the location coordinates of the terminal. There are a total of three base stations, that is, C1, C2, and C3, respectively, used for the primary estimation of the location coordinates of the terminal.

Even if there are four base stations used to estimate the position coordinates of the terminal, one reference base station is selected and vectors for the remaining base stations are obtained in the same manner as described above, and the final corrected position is calculated by the sum of these vectors do.

The positioning apparatus 200 may secure the primary estimated position, the position of the base station, left-right direction angles and up-down direction angle information of the base station antenna. By using gain information according to the angle of the base station antenna, dBi for each base station antenna at the primary estimated position is secured.

Referring to FIG. 12 , the positioning apparatus 200 calculates an azimuth based on the location coordinates A of the terminal and the location coordinates C1, C2, and C3 of each base station (S301). At this time, the positioning apparatus 200 can calculate the angle from the zero point to the position coordinate (A) of the terminal 100 as the azimuth between the terminal and the corresponding base station by using the position coordinates (C1, C2, C3) of each base station as the zero point. have.

In the base station database provided by the positioning device 200, antenna gain information of the base station is stored for each base station identifier. The antenna gain information consists of a gain value according to an antenna installation angle for each antenna provided by each base station. In this case, the unit of the gain value of the antenna is dBi.

The positioning device 200 checks the gain value of the antenna having the installation angle including the calculated azimuth from the base station database based on the installation angle of each of the base station antennas stored in the base station database (S303). For example, if the azimuth is 40 degrees, it is possible to check the gain value of the antenna in which the antenna installation angle is set to 0 to 50 degrees. In this case, the positioning device 200 may also check the installation direction mapped to the installation angle of the antenna.

That is, the positioning apparatus 200 may check the pattern of the antenna installed in the corresponding base station from the base station database through the azimuth, and check the dBi of the antenna expected from the first estimated location of the terminal and the location of the base station. Since dBi means additional gain that can be secured from the antenna, it can be estimated that the smaller the value, the lower the transmission signal strength than expected. Accordingly, the positioning apparatus 200 may estimate the direction and magnitude of the vector by converting the additional gain value of another base station into dB based on the position of the base station having the smallest dBi value. The positioning apparatus 200 selects, as a unit vector, a vector obtained from a base station having the smallest difference in antenna addition gain value, and sets magnitudes of vectors obtainable from the remaining base stations based on the unit vector to estimate a direction. A correction is made by shifting the primary terminal estimated position from the estimated direction.

The positioning device 200 checks the antenna gain value for each of the three base stations in this way (S303). Here, the antenna gain refers to a transmit antenna gain.

The positioning apparatus 200 sets the first base station having the smallest confirmed antenna gain value as the reference base station (S305).

The positioning device 200 converts the gain value of the antenna in dB units (S307). Specifically, the positioning apparatus 200 sets the antenna gain value of the reference base station to 0 dB, and sets a value expressed in dB of each antenna gain difference between other base stations and the reference base station as the antenna gain value of the corresponding base station ( S307).

The positioning device 200 may estimate the transmission distance between the terminal and the base station expected from the transmission loss model according to the downtown, sub-center, and outlying areas based on the RSRP received by the terminal. In this case, a method of estimating the transmission distance from the transmission loss model may use a transmission loss model according to a region defined in 3GPP (3GPP standard document TR38.901). It is common to estimate the number of buildings per unit area as a criterion for classifying downtown, sub-center, and outlying areas.

If the information on at least three base stations is not reflected when determining the location of the terminal, the positioning device 200 determines the terminal location determined in step S107 and/or step S109 as the final location (S115).

The positioning device 200 applies the signal attenuation model to the RSRP of the second base station with the second smallest antenna gain converted to dB, and the first transmission distance, that is, the first transmission between the terminal estimated position (A) and the second base station. The distance is calculated (S309).

The positioning device 200 calculates the second transmission distance between the terminal estimated position (A) and the second base station by applying the antenna gain value converted to dB to the RSRP of the second base station (S311).

The positioning device 200 selects a base station having a minimum difference between the reference base station and the antenna gain value, and a second corresponding to RSRP after reflecting the first transmission distance and the antenna gain corresponding to the RSRP before reflecting the antenna gain value. A transmission distance is obtained, and the difference between these transmission distances is set as a unit distance (S313). And the positioning device 200 calculates a vector of the second base station based on the unit distance and the antenna installation direction of the second base station (S313).

The positioning device 200 applies the signal attenuation model to the RSRP of the third base station with the third smallest antenna gain converted into dB, the first transmission distance, that is, the first transmission between the terminal estimated position (A) and the third base station. The distance is calculated (S315).

The positioning device 200 calculates a second transmission distance between the terminal estimated position (A) and the second base station by applying the antenna gain converted to dB to the RSRP of the second base station (S317).

The positioning device 200 sets the difference between the first transmission distance and the second transmission distance as a unit distance, and calculates a vector of the third base station based on the unit distance and the antenna installation direction of the third base station (S319).

The positioning apparatus 200 corrects the estimated position of the terminal through the sum of the vector of the second base station and the vector of the third base station (S321).

Referring to FIG. 11 , for example, assuming that the antenna gain value of C1 is -3 dBi, the antenna gain value of C2 is 0 dBi, and the antenna gain value of C3 is 3 dBi, the reference base station becomes C1. If the antenna gains of C1, C2, and C3 are -3dBi, -3dBi, and -2dBi, respectively, since there are two minimums, the third value, -2dBi, may be set to C3 as the reference base station.

In this case, the location of the terminal is referred to as A.

The positioning device 200 sets the antenna gain value of C1 to 0 dB. Since the difference between the antenna gain value between C1 and C2 is 3 dBi, the positioning device 200 sets the antenna gain value of C2 to 3 dB. Since the difference between the antenna gain value between C1 and C3 is 6 dBi, the positioning device 200 sets the antenna gain value of C3 to 6 dB.

The positioning device 200 extracts a unit distance by using C2 having a second dBi smaller. That is, the positioning device 200 may calculate the first transmission distance d2 between the terminal and C2 by applying the RSRP received from C2 by A to the signal attenuation model. As such, since the method of calculating the transmission distance uses a known technique, a detailed description thereof will be omitted.

The positioning device 200 corrects the RSRP received from A by C2 by reflecting the antenna gain value of C2. Since the positioning device 200 has an antenna gain value of 3 dB (the difference in antenna gain between C1 and C2), 3 dB is subtracted from RSRP. As such, the positioning device 200 calculates the second transmission distance (d2') between A and C2 by applying the corrected RSRP to the signal attenuation model. The positioning device 200 calculates the difference between the first transmission distance (d2) calculated before correcting the RSRP and the second transmission distance (d2') calculated using the corrected RSRP, and transmits per 'a' dB of RSRP Calculate the basis for the distance being 'b' meters.

를 취한 만큼 증가한다. 즉, C3의 전송 거리는 약 28m가 된다. 이처럼, 측위 장치(200)는 C2에 대한 증가된 전송 거리를 크기로 가지고 C2의 안테나 설치 방향을 가지는 C2 벡터(

)를 산출한다. 그리고 측위 장치(200)는 C3에 대한 증가된 전송 거리를 크기로 가지고 C3의 안테나 설치 방향을 가지는 C3 벡터(

)를 산출한다.For example, if the RSRP of C2 is -70dBm, the calculated transmission distance is 130m, and the corrected RSRP by subtracting 3dB (the difference in antenna gain between C1 and C2) from the RSRP of C2 is -73dBm, if the calculated transmission distance is 150m , increased transmission distance by 3dB reduction is 20m. Therefore, 20 m becomes the unit distance. Since RSRP of C3 is 3dB different from RSRP of C2, the transmission distance of C3 is 3dB higher than that of C2 (20m).

increases by the amount taken. That is, the transmission distance of C3 becomes about 28 m. As such, the positioning device 200 has an increased transmission distance for C2 as a size and a C2 vector (

) is calculated. And the positioning device 200 has an increased transmission distance for C3 as a size and a C3 vector (

) is calculated.

)와 C3 벡터(

)의 대각선 방향에 위치하는 보정된 단말 위치를 산출할 수 있다.The positioning device 200 uses A as a reference point, and from A to C2 vector (

) and the C3 vector (

) can calculate the corrected position of the terminal located in the diagonal direction.

Here, in order to correct the location of the terminal, it is necessary to obtain and calculate a vector for each base station, so that at least three PCIs must be detected. In addition, since the gain of the antenna is utilized, it is relatively insensitive to frequency characteristics, so that it can be collectively applied to other bands.

The positioning device 200 may perform the processes of FIGS. 11 and 12 with respect to frequencies at which at least three PCIs are detected.

In addition, the positioning device 200 may utilize a weight proportional to the number of detected PCIs for terminal position correction when integrated for all frequencies. In order to improve accuracy, when the n-1st correction position and the nth correction position converge or continue to exist within a specific range, the arithmetic mean value of the position values existing in the specific range may be derived as the final terminal location.

13 is a diagram for explaining a terminal position correction method according to another embodiment of the present invention, which is additionally performed after the step of FIG. 12 .

Referring to FIG. 13 , the positioning apparatus 200 calculates an azimuth for each base station based on the terminal position corrected through the process of FIG. 12 and the position of each base station used for estimating the terminal position ( S401 ). The positioning device 200 checks each antenna installation angle from the base station database using the calculated azimuth angles, and checks an antenna gain value mapped to each antenna installation angle ( S403 ). Here, steps S401 and S403 are the same as steps S301 and S303 of FIG. 12, respectively, except that the terminal location corrected through FIG. 12 is used.

The positioning device 200 determines whether a change in the smallest antenna gain value occurs before and after correction (S405). That is, it is determined whether the smallest antenna gain value in FIG. 12 and the smallest antenna gain value confirmed in FIG. 13 are different from each other ( S405 ), and if they are different, steps S307 to S321 of FIG. 12 are performed. In this case, the terminal location used in steps S307 to S321 is the terminal location corrected through FIG. 12, and information derived in steps S401 and S403 is used for the azimuth, antenna gain, and antenna installation direction.

The positioning device 200 calculates a change amount between the terminal position corrected at the previous time point and the terminal position corrected at the current time point (S411). That is, the amount of change between the corrected terminal position calculated through FIG. 12 and the corrected terminal position calculated after step S409 is calculated.

The positioning device 200 determines whether there is no change calculated in step S411 (= 0), or converges to a specific threshold amount (within 5 m range) (S413), and if not, the corrected terminal position calculated in step S409 Steps S401 to S413 are repeated using

If the condition of step S413 is satisfied, the positioning apparatus 200 determines the arithmetic mean value of the corrected terminal positions calculated so far as the final terminal position (S415).

In the process of performing positioning, it is impossible to reflect the gain value because the location of the terminal cannot be known. Therefore, when the antenna gain is reflected based on the location of the terminal, the accuracy can be improved by further correcting the location on the assumption that the transmission distance is longer for the base station having a large gain.

As described above, according to the embodiment of the present invention, the terminal position is estimated using the coordinates of the base stations having the same center frequency and band based on the EARFCN, and the estimated terminal position is corrected in consideration of the antenna characteristics. It is possible to minimize performance degradation due to differences in characteristics of radio waves.

The embodiment of the present invention described above is not implemented only through the apparatus and method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium in which the program is recorded.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improved forms of the present invention are also provided by those skilled in the art using the basic concept of the present invention as defined in the following claims. is within the scope of the right.

Claims (12)

As a method for a positioning device to determine the location of a terminal,
Receiving, by the terminal, a plurality of base station information received from a plurality of base stations adjacent to the terminal from the terminal;
Detecting a base station identifier, a base station frequency, and a received signal strength from the plurality of base station information, respectively, and confirming a base station location corresponding to each base station identifier from a base station database, and
estimating the location of the terminal using base station locations corresponding to base station identifiers respectively detected at at least two different base station frequencies and detected received signal strengths,
The estimating step is
Method of estimating the location of the terminal by applying a path-loss model between base stations using different frequencies, or a transmission distance ratio according to the received signal strength of each of the base stations to the locations of each of the base stations . In claim 1,
After the estimating step,
Correcting the estimated location of the terminal by reflecting the antenna gain value of each of the base stations used in estimating the location of the terminal
A method further comprising: In claim 2,
The correcting step is
checking an antenna gain value of each of the base stations, and selecting a first base station as a reference based on the antenna gain value;
selecting a second base station and a third base station based on a difference between the first base station and an antenna gain value;
Estimate the transmission distance between the estimated position of the terminal and the second base station using the antenna gain value and the received signal strength of the second base station, confirm the antenna installation direction of the second base station, and the transmission distance and the calculating a first vector configured in an installation direction;
Estimate the transmission distance between the estimated position of the terminal and the third base station using the antenna gain value and the received signal strength of the third base station, check the antenna installation direction of the third base station, and the transmission distance and the calculating a second vector configured in the installation direction, and
moving the estimated position of the terminal to a point where the first vector and the second vector are summed, and determining the moved position as the terminal position
A method comprising In claim 3,
After the correcting step,
Repeating the correction using the changed antenna gain value of each base station generated at the moved position, and
When there is no change in the corrected position calculated through repetition or the change converges within the critical region, determining the arithmetic mean value of the corrected positions calculated so far as the final position of the terminal
A method further comprising: In claim 2,
The step of estimating the location of the terminal comprises:
A method of estimating a location of a terminal by applying a path-loss model to a location of a base station corresponding to each base station identifier when one base station identifier is detected at at least two different base station frequencies. In claim 2,
The step of estimating the location of the terminal comprises:
When two base station identifiers are detected at at least two different base station frequencies, the location of the terminal is estimated using the intersection point or the nearest point between Apollonius circles respectively generated around the base station location corresponding to each base station identifier, Method . In claim 2,
The step of estimating the location of the terminal comprises:
When at least three base station identifiers are detected at at least two different base station frequencies and at least two base station identifiers are detected at at least two different base station frequencies, each base station location corresponding to the at least three base station identifiers is used to Estimating the arithmetic average of the calculated first position and the calculated second position using each position corresponding to the at least two base station identifiers as the terminal position,
The first location is
It is estimated using a transmission distance ratio according to the received signal strength received from each base station around the base station location corresponding to the at least three base station identifiers,
The second location is
The method of claim 1, which is an intersection point or a nearest point between Apollonius circles respectively generated around a base station location corresponding to the at least two base station identifiers. In claim 2,
The step of estimating the location of the terminal comprises:
a first in which at least three base station identifiers are detected at at least two different base station frequencies, at most one base station identifier is detected at at least one different base station frequency, and at most two base station identifiers are detected at at least one different base station frequency In the case or the second case in which at least three base station identifiers are detected at at least three different base station frequencies, a transmission distance according to the received signal strength received from each base station with respect to the base station location corresponding to the at least three base station identifiers How to use rain. In claim 2,
The step of estimating the location of the terminal comprises:
When at least three base station identifiers are detected at the first base station frequency and up to two base station identifiers are detected at at least one second base station frequency different from the first base station frequency, base station locations corresponding to the at least three base station identifiers using the arithmetic mean value between the first position estimated from and the second position estimated from the base station position corresponding to the base station identifier detected at the second base station frequency,
The first location is
Using a transmission distance ratio according to the received signal strength received from each base station around the base station location corresponding to the at least three base station identifiers,
The second location is
using the transmission distance ratio or path loss model. As a method for a positioning device to determine the location of a terminal,
Receiving information about a base station adjacent to the terminal from the terminal;
determining whether there are at least two base stations adjacent to the terminal and each base station uses different frequencies based on the received information;
When one base station using at least two different base station frequencies is detected, estimating the location of the terminal by applying a path-loss model to the detected base station location;
When two base stations using at least two different base station frequencies are respectively detected, the location of the terminal is estimated using the intersection or the nearest point between Apollonius circles respectively generated based on the received signal strength based on the location of each base station. step, and
When the number of base stations using at least two different base station frequencies is detected differently at each base station frequency, at least one first location estimated from the base station location detected at the first base station frequency and at least one second base station frequency Estimating the location of the terminal using an arithmetic mean value between the second locations estimated from the detected base station location
A method comprising In claim 10,
After estimating the location of the terminal,
If there are at least three base stations used to determine the location of the terminal, check the azimuth and vector of each base station using the estimated location of the terminal and the location of each base station used for estimating the location of the terminal, and use the azimuth correcting the estimated position of the terminal based on the confirmed antenna gain for each base station
A method further comprising: In claim 11,
The first position and the second position,
It is estimated using at least one of the path loss model, the intersection or nearest point between the Apollonius circles, the transmission distance ratio according to the received signal strength received from each base station based on the location of each base station, and the inner division point of the line segment connecting the base stations. , Way.

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