JP4870529B2 - Wireless positioning system, base station apparatus, positioning method, and program - Google Patents

Description

  The present invention relates to a wireless positioning system, a base station apparatus, a positioning method, and a program.

  There is known a wireless positioning system that performs positioning by receiving positioning signals from a positioning object (such as a mobile station device) by three or more access point devices. As a specific example, a large number of access point devices are installed in a room, and a positioning signal from a positioning object is received by at least three of the access point devices, so that the positioning object can be detected in the room. One that measures the position can be mentioned. Non-Patent Document 1 describes the principle of such positioning.

  As shown in Non-Patent Document 1, the wireless positioning system is configured such that the position of each access point device and the difference between the access point devices in the time required to receive the positioning signal transmitted by the object to be measured (hereinafter referred to as “the positioning device”) , The positioning signal reception time difference), and the position of the positioning object is calculated.

  The calculation of the positioning signal reception time difference will be described. First, each access point device measures the reception time of the positioning signal based on the clock held by itself. The wireless positioning system calculates the difference between the reception times and sets it as the positioning signal reception time difference. However, in order to correctly calculate the positioning signal reception time difference by such processing, it is necessary to express the reception time of the positioning signal in each access point device using a time notation based on a common timing. Therefore, each access point device performs a process for sharing a common timing (referred to as a time synchronization process).

Patent Document 1 discloses an example of the time synchronization process. In this example, one reference station device that transmits a signal for time synchronization (referred to as a reference signal) is provided. The reference station device receives the positioning signal as with the access point device, and transmits the reference signal as soon as the positioning signal is received. Each access point device stores the distance to the reference station device in advance, receives the reference signal transmitted by the reference station device, and based on the reception timing and the stored distance, the common timing To get. And the reception time of a positioning signal is acquired using the time notation on the basis of the acquired timing.
Rick Roberts et al., “Ranging Subcommittee Final Report”, IEEE P802.15, USA, IEEE (The Institute of Electrical and Electronics Engineers, headquartered in the United States), November 22, 2004, P802.15, p. . 3-9 Japanese Patent Laid-Open No. 2005-140617

  However, according to the technique described in Patent Document 1, the reference station device is a position where a positioning signal can be received from any position within the positioning target area, and the reference signal can reach all access point devices. Since it has to be installed at a position, there is a problem that it is not easy to select the installation position and the area of the positioning target area is limited. Further, since there is such a restriction on the installation position, there is a problem that it is not easy to add an access point device once the installation of each device is once completed.

  Although these problems seem to be solved by installing a plurality of reference station apparatuses, the technique described in Patent Document 1 has a problem that a plurality of reference station apparatuses cannot be installed. That is, when a plurality of reference station devices are installed, a plurality of reference station devices receive one positioning signal, and as a result, the access point device may receive two or more reference signals (this is called a reference signal collision). .) In this case, each access point device cannot appropriately acquire the common timing as a reference.

  Accordingly, one of the objects of the present invention is to provide a wireless positioning system, a base station apparatus, a positioning method, and a program that allow a plurality of reference station apparatuses to be installed by preventing the occurrence of a reference signal collision.

  A wireless positioning system according to the present invention for solving the above-described problems is a wireless positioning system that includes a plurality of base station devices and measures the position of an object to be measured using at least a part of the plurality of base station devices. A priority order of reference signal transmission is assigned to each of the base station apparatuses, and each base station apparatus acquires priority order acquisition means for acquiring the priority order assigned to the base station apparatus, and the measured object. Positioning signal receiving means for receiving a positioning signal from the base station apparatus and acquiring the reception time based on a clock held by the base station apparatus; and after receiving the positioning signal by the positioning signal receiving means, the priority order obtaining means The reference signal transmitting means for transmitting the reference signal and the reference signal transmitted by another base station apparatus at a timing based on the priority order acquired by the base station apparatus, and receiving the reference signal. Reference signal receiving means for acquiring the reception time based on the base station, and the radio positioning system is based on the reception time of the positioning signal and the reception time of the reference signal acquired in each base station device And position determining means for determining the position of the object to be measured.

  According to this, since each base station apparatus transmits the reference signal at the timing based on the priority, even if a plurality of base station apparatuses are installed, the occurrence of the collision of the reference signals is prevented. That is, a plurality of base station devices that function as reference station devices can be installed.

  Further, in the wireless positioning system, each base station apparatus, when the reference signal is received by the reference signal receiving means, a reference signal transmission restricting means for restricting the transmission of the reference signal by the reference signal transmitting means. It is good also as including.

  According to this, since each base station apparatus restricts transmission when a reference signal is received from another base station apparatus, collision of the reference signals is more reliably prevented.

  Each wireless positioning system includes distance information acquisition means for acquiring distance information indicating a distance between the base station apparatuses, and the position determination means includes the reference acquired in the base station apparatuses. The position of the positioning object is determined based on each reception time of the signal and the positioning signal and distance information indicating a distance between each base station apparatus and the base station apparatus that has transmitted the reference signal. It's good.

  According to this, the position of a to-be-measured object can be determined based on distance information.

  In each of the wireless positioning systems, the priority order may be determined based on the shape and area of a positioning target area and the installation position of each base station device.

  According to this, it can be expected that the number of base station apparatuses to which the reference signal transmitted by one base station apparatus reaches will increase.

  Further, in each of the radio positioning systems, the priority order may be determined based on the number of other base station apparatuses that can communicate with each base station apparatus.

  Also by this, it can be expected that the number of base station apparatuses to which the reference signal transmitted by one base station apparatus reaches will increase.

  Further, in each of the radio positioning systems, the priority order may be determined based on an antenna radiation pattern of each base station device.

  Also by this, it can be expected that the number of base station apparatuses to which the reference signal transmitted by one base station apparatus reaches will increase.

  Further, in each of the wireless positioning systems, the wireless positioning system includes a storage unit that stores in advance the position of each of the plurality of positioning objects, and the priority is stored by the storage unit for each of the positioning objects. It is good also as being determined for every said to-be-measured object based on the position to be performed.

  According to this, since the priority order is determined for each positioning object based on the position stored for each positioning object (= the position where each positioning object is likely to exist), an efficient reference signal Transmission can be realized.

  Further, in each of the radio positioning systems, the priority is determined based on a rate at which position determination by the position determination unit is completed when any one of the base station apparatuses receives the positioning signal. It is good as well.

  According to this, it becomes possible to use a priority with a high ratio that has been successfully determined in the past later.

  In each of the wireless positioning systems, a predetermined test signal may be transmitted and received between the base station apparatuses, and the priority order may be determined based on the communication status.

  According to this, for example, it is possible to increase the priority as the base station apparatus has a larger number of other base station apparatuses that can suitably transmit and receive the test signal.

  Further, the base station apparatus according to the present invention receives priority order acquisition means for acquiring the priority order of reference signal transmission assigned to the base station apparatus, and receives a positioning signal from the positioning object, and the base station apparatus holds A positioning signal receiving means for acquiring the reception time based on the clock, a timing of receiving the positioning signal by the positioning signal receiving means, and a priority order obtained by the priority order obtaining means. And a reference signal transmitting means for transmitting the reference signal.

  A positioning method according to the present invention is a positioning method for positioning the position of a positioning object using a wireless positioning system including a plurality of base station devices, and transmits a reference signal to each of the base station devices. A priority order is assigned, and each base station apparatus obtains the priority order assigned to the base station apparatus, and each base station apparatus receives a positioning signal from the positioning object. A positioning signal receiving step for obtaining the reception time based on the clock held by the base station device, the base station device receiving the positioning signal in the positioning signal receiving step, and the priority A reference signal transmission step of transmitting the reference signal at a timing based on the priority order acquired in the acquisition step, and another base station device transmitted Receiving a serial reference signal, based on the clock and a reference signal reception step of acquiring the receiving time, comprising a.

  A program according to the present invention includes a plurality of base station devices, and in the wireless positioning system that measures the position of a positioning object using at least a part of the plurality of base station devices, A program for causing each base station apparatus to function, wherein each of the base station apparatuses is assigned a priority order of reference signal transmission, and each of the computers acquires the priority order assigned to the base station apparatus. Priority acquisition means, positioning signal reception time acquisition means for acquiring a reception time of a positioning signal received from the positioning object based on a clock held by the base station apparatus, after the positioning signal is received, Reference signal transmission control means for causing the transmission means to transmit the reference signal at a timing based on the priority order acquired by the priority order acquisition means; Based on the fine said clock is a program for further functions as a reference signal receiving means, for obtaining a reception time of the reference signal received from another of said base station apparatus.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a system configuration diagram of a wireless positioning system 1 according to the present embodiment. As shown in the figure, the radio positioning system 1 shows a plurality of base station devices 10 (in FIG. 1, six base station devices 10 from a base station device 10-1 to a base station device 10-6). ), The positioning calculation server device 20, the positioning terminal device 30 as a positioning object, and the network 40.

  Each base station apparatus 10 is distributedly installed in a certain room (positioning target area in the present embodiment) and is configured to be communicable with the positioning calculation server apparatus 20 via the network 40. Each base station apparatus 10 receives a positioning signal (in FIG. 1, this positioning signal is indicated by an arrow R) that is wirelessly transmitted by the measured terminal apparatus 30 in a radial manner.

  Furthermore, each base station apparatus 10 is comprised so that wireless communication can be performed between each other. Specifically, a reference signal for synchronizing time between base station apparatuses 10 (synchronization signal; this reference signal is indicated by arrow B in FIG. 1) is transmitted between base station apparatuses 10 wirelessly. It is configured to be able to send and receive.

  Each base station apparatus 10 is provided with a time measuring unit for acquiring the current time, and also performs a process of acquiring a positioning signal reception time and a reference signal transmission / reception time using the time measuring unit and transmitting them to the positioning calculation server apparatus 20. .

  The positioning calculation server device 20 receives the positioning signal reception time and the reference signal transmission / reception time from each base station device 10, and calculates the position of the positioning terminal device 30 based on these.

  Hereinafter, the hardware configuration of the base station apparatus 10 will be described. FIG. 2 is a hardware configuration diagram of the base station apparatus 10. As shown in the figure, the base station apparatus 10 includes an antenna 11, a radio unit (RF) 12, and a signal processing unit (DSP) 13. The signal processing unit 13 includes a microcontroller (MPU) 131, a storage medium (MEM) 132, a counter (COUNT) 133, and a baseband signal processing unit (BB). 134 is comprised.

  The signal processing unit 13 performs packet generation processing, arithmetic processing, signal processing (such as modulation / demodulation), and timing processing. Specifically, the microcontroller 131 performs various arithmetic processes and state transition management during each process. The counter 133 performs timing processing for acquiring the current time by counting timing pulses at which a clock (not shown) oscillates.

  The baseband signal processing unit 134 performs packet generation processing and baseband signal processing such as data modulation / demodulation and spreading / despreading. Regarding this packet generation processing, the storage medium 132 stores coordinates indicating the position of the base station device 10 in the room, a base station priority (BP) described later, identification information (ID) of the base station device 10, and the like. The baseband signal processing unit 134 generates a packet based on the information stored in the storage medium 132. More specifically, a packet forming the reference signal (hereinafter referred to as a reference signal packet) and a packet including the positioning signal reception time and the reference signal transmission / reception time (hereinafter referred to as a reception time packet) are generated. . Here, each packet includes a preamble part, a header part, and a data part, and the reference signal packet includes information indicating that the packet is a reference signal in the data part. The reception time packet includes each reception time in its data part.

  The radio unit 12 receives an input of a packet generated and modulated by the signal processing unit 13, performs amplification and frequency conversion processes, and then radiates the packet into the air via the antenna 11. Further, it receives an input of a signal arriving at the antenna 11, performs amplification and frequency conversion processing, and outputs the processed signal to the signal processing unit 13.

  Hereinafter, functions of the base station device 10, the positioning calculation server device 20, and the measured terminal device 30 will be described in detail with reference to functional block diagrams of the respective devices.

  FIG. 3 is a schematic block diagram illustrating functional blocks of the base station device 10, the positioning calculation server device 20, and the measured terminal device 30. In the figure, only one base station apparatus 10 is shown for simplicity, but actually, each base station apparatus 10 is configured to include similar functional blocks.

  As shown in FIG. 3, the base station apparatus 10 includes an antenna 11, a positioning signal receiving unit 50, a time transmitting unit 51, a BP storage unit 52, a reference signal transmitting unit 53, a reference signal receiving unit 54, and a reference signal transmission limiting unit 55. It is comprised including. The positioning calculation server device 20 includes a distance information storage unit 21 and a position determination unit 22. Further, the positioning terminal device 30 includes a positioning signal transmission unit 31 and an antenna 32.

  The positioning signal transmission unit 31 uses a antenna 32 to form a positioning signal packet (hereinafter referred to as a positioning signal packet) in response to a time trigger by a timer (not shown) or a positioning start command from the base station device 10 or the like. .) Over the air. Here, the positioning signal packet is a packet including information indicating that the packet is a positioning signal in its data portion.

  The positioning signal receiving unit 50 uses the antenna 11 to receive the positioning signal packet wirelessly transmitted by the terminal device 30 to be measured. At that time, the reception time (positioning signal reception time) is acquired using the counter 133 and is output to the time transmission unit 51. The time transmitter 51 temporarily stores the positioning signal reception time input from the positioning signal receiver 50.

  The BP storage unit 52 stores a BP (reference station priority) assigned to the base station apparatus 10. BP is information indicating the priority order of reference signal transmission, and is assigned to each base station apparatus 10 in advance. Although the specific content of BP is mentioned later, in an example, the integer of 0-20 is allocated to each base station apparatus 10 as BP.

  The reference signal transmission unit 53 acquires the BP assigned to the base station apparatus 10 from the BP storage unit 52, and uses the antenna 11 at a timing based on the BP after receiving the positioning signal packet by the positioning signal receiving unit 50. Then, the reference signal packet is wirelessly transmitted. In a specific example, the reference signal transmission unit 53 determines the standby time based on the BP, and after the positioning signal packet is received by the positioning signal reception unit 50, the reference signal packet is transmitted when the determined standby time has elapsed. Send.

  The reference signal receiving unit 54 receives a reference signal packet transmitted by another base station apparatus 10. Specifically, when the data portion of the packet demodulated by the signal processing unit 13 (FIG. 2) includes information indicating that it is a reference signal, the reference signal receiving unit 54 designates the packet as a reference signal packet. As received. At that time, the reception time (reference signal reception time) is acquired using the counter 133 and output to the time transmission unit 51. The time transmission unit 51 generates a reception time packet including the identification information of the base station device 10, the reference signal reception time input from the reference signal reception unit 54, and the positioning signal reception time temporarily stored. , To the positioning calculation server device 20.

  Note that the reference signal receiving unit 54 may regard the first packet received within a certain time after receiving the positioning signal packet as the reference signal packet. In this case, the reference signal receiving unit 54 can proceed without waiting for completion of the demodulation processing of the signal processing unit 13, so that the reception time packet transmission processing can be transmitted more quickly. In this case, information indicating the reference signal may not be included in the data portion of the reference signal packet.

  The reference signal transmission restriction unit 55 restricts the transmission of the reference signal packet by the reference signal transmission unit 53 when the reference signal packet is received by the reference signal reception unit 54. In other words, when the reference signal transmission unit 53 has not yet transmitted the reference signal packet when the reference signal packet is received by the reference signal reception unit 54, the reference signal transmission unit 53 stops transmission of the reference signal packet. .

  The distance information storage unit 21 stores distance information indicating the distance between the base station devices 10. This distance information may be a specific distance or a time required for signal arrival when a signal is transmitted from one base station apparatus 10 to the other base station apparatus 10. This distance information is written in the distance information storage unit 21 by the user.

  The distance information storage unit 21 may store base station apparatus coordinate information that represents the position of each base station apparatus 10 in a predetermined coordinate system. In this case, the user writes the base station device coordinate information of each base station device 10 in the distance information storage unit 21.

  When receiving the positioning signal reception time and the reference signal reception time from each base station device 10, the position determination unit 22 acquires distance information from the distance information storage unit 21, and the reference signal packet and the positioning signal in each base station device 10. Based on each packet reception timing and distance information indicating a distance between each base station apparatus 10 and the base station apparatus 10 that has transmitted the reference signal packet, the position of the terminal apparatus 30 to be measured is determined.

  When the distance information storage unit 21 stores the base station device coordinate information, the position determination unit 22 determines the distance between the base station devices 10 based on the base station device coordinate information of each base station device 10. By calculating, distance information is acquired.

  The processing of the position determination unit 22 will be described in detail. FIG. 4 is an explanatory diagram for explaining the processing of the position determination unit 22. In the figure, the measured terminal device 30 transmits a positioning signal packet at timing T1, the base station device 10-1 transmits a reference signal packet at timing T2, and the base station devices 10-2, 3 and 4 receive positioning signals. It is assumed that the reception time of the packet and the reference signal packet is transmitted to the positioning calculation server device 20.

Hereinafter, the timing T1 at which the positioning terminal device 30 transmits the positioning signal packet is represented as t _{0 by the} time based on the clock of the positioning terminal device 30, and the position determination unit 22 uses the base station device 10-n (n = 2). , a positioning signal reception time and a reference signal reception time received from 3,4) and t _n and s _n, respectively, the distance information indicating the distance between the base station apparatus 10-n and the base station apparatus 10-1 times l _n It shall be expressed as

The position determination unit 22 has to obtain the position of the positioning terminal device 30 to determine the position of the base station device 10-n for the time required to receive the positioning signal packet transmitted by the positioning terminal device 30. Difference between them (positioning signal reception time difference). One method for determining this, the positioning unit 22 is first determined time A _n up to the positioning terminal 30 is received by each base station apparatus 10-n from the transmission of the positioning signal packets, Further, a positioning signal reception time difference B _{m, n} = A _n −A _m between the base station device 10-n and the base station device 10-m (m = 2, 3, 4 where m ≠ n) is calculated. A method is conceivable. However, since each positioning signal reception time t _n is a time represented based on the clock of each base station apparatus 10-n, synchronization between the measured terminal apparatus 30 and each base station apparatus 10-n as shown in FIG. It does not hold the relationship of _a n ₌ t n -t ₀ in the state that are not taken. Therefore, the position determination unit 22 can not determine the time A _n by such calculations. Therefore, B _{m, n} cannot be obtained.

Therefore, the position determination unit 22 calculates B _{m, n} as follows. That is, the position determination unit 22 first represents the timing T2 at which the base station device 10-1 transmits the reference signal packet based on the clock of each base station device 10-n. Specifically, to calculate a time _s n -l _n for each base station apparatus 10-n. Time s _n -l _n thus calculated, even those of which base station apparatus 10-n, show the common timing T2.

Then, the position determination unit 22, for each base station apparatus 10-n, the elapsed time from the positioning signal reception time _{t n,} to the time point _s n -l _n corresponding to the common timing T2 _{{(s n} -l n ) −t _n }. Further, the position determination unit 22 determines the difference between the elapsed times {(s _n −l _n ) −t _n } − {(s _m −l _m ) between the base station device 10-n and the base station device 10- _m. ) −t _m }. The value thus calculated is B _{m, n} . Position determining unit 22, thus calculating B _{m, n,} the respective B _{m calculated,} based on _n, to determine the position of the positioning terminal device 30.

However, in order for the position determination unit 22 to determine the position of the positioning terminal device 30 based on each B _{m, n} , the positioning signal reception time difference B _{m, n} between the three base station devices 10 _-n is is necessary. When this cannot be obtained, for example, when the _number of base station apparatuses 10 that transmitted both the positioning signal reception time t _n and the reference signal reception time s _n is less than three, the position determination by the position determination unit 22 fails.

  The processing described above will be described in more detail again with reference to the processing sequence of the wireless positioning system 1.

  FIG. 5 is a diagram showing a processing sequence of the wireless positioning system 1. As shown in the figure, first, the terminal apparatus 30 to be measured transmits a positioning signal packet (S1). When receiving each positioning signal packet, each base station apparatus 10 measures the reception time and temporarily stores it (S2).

  Further, when receiving the positioning signal packet, the base station apparatus 10 acquires the BP assigned to the base station apparatus 10 (S3). Note that the base station apparatus 10 may acquire the BP before the positioning signal packet is received. Further, information indicating the timing of transmitting the reference signal packet (waiting time determined based on BP) may be acquired before the positioning signal packet is received. In this way, the processing of the base station apparatus 10 after receiving the positioning signal packet can be reduced, so that the transmission delay of the reference signal packet is suppressed. This is particularly effective when a reference signal is to be transmitted (reflectively) immediately after receiving a positioning signal packet.

  Next, the base station apparatus 10 waits for the transmission of the reference signal packet for the standby time determined based on BP (S4), and transmits the reference signal packet after the standby time has elapsed (S5). The base station device 10 that has received the reference signal packet from another base station device 10 measures the reception time of the reference signal packet, and sends it to the positioning calculation server device 20 together with the temporarily stored positioning signal packet reception time. At the same time as transmitting (S6), the transmission of the reference signal packet is canceled.

  The positioning calculation server device 20 acquires distance information indicating the distance between the base station devices 10 (S7), and uses the distance information and the positioning signal reception time and the reference signal reception time received from each base station device 10. Based on this, the position of the measured terminal device 30 is determined (S8).

  Next, paying attention to the processing of the base station apparatus 10, it will be described in more detail again.

  FIG. 6 is a diagram illustrating a processing flow of the base station apparatus 10. As shown in the figure, when receiving the positioning signal packet (S11), the base station apparatus 10 measures the positioning signal reception time based on the counter 133 in the own apparatus and temporarily stores it (S12). Next, the base station apparatus 10 acquires a waiting time t_wait_sync determined based on the BP, and waits for the arrival of a reference signal packet from another base station apparatus 10 until the waiting time t_wait_sync elapses (S13). ). Note that the waiting time t_wait_sync may be obtained by adding, for example, a time (positive or negative) determined based on a random value according to a Gaussian distribution to a waiting time determined based on the BP.

  When the reference signal packet is received during the standby in S13 (Yes determination in S14), the base station apparatus 10 measures the reception time and sends it to the positioning calculation server apparatus 20 together with the temporarily stored positioning signal reception time. (S16), and the process ends. On the other hand, if not received, the base station apparatus 10 transmits a reference signal packet (S15) and ends the process. The reason for waiting for transmission in S17 is that there may be a base station apparatus 10 to which the same BP is assigned in the positioning target area. It is optimal to wait for a waiting time determined based on a random value, but this waiting time is set in a range that does not reverse the waiting time determined based on BP.

  Next, paying attention to the processing of the positioning calculation server device 20, a more detailed description will be given again.

  FIG. 7 is a diagram illustrating a processing flow of the positioning calculation server device 20. As shown in the figure, the positioning calculation server device 20 first receives a positioning signal reception time and a reference signal reception time from each base station device 10 (S21). Then, it is determined whether or not the positioning signal reception time and the reference signal reception time have been received from three or more base station devices 10 within a predetermined time from the first positioning signal reception time reception timing (S22).

  When it determines with not having received in S22, the positioning calculation server apparatus 20 determines with positioning NG (S23), and complete | finishes a process. This is because a positioning signal reception time difference between three or more base station apparatuses 10 is necessary for position determination.

  On the other hand, when it determines with having received in S22, the positioning calculation server apparatus 20 acquires distance information (S24), determines the position of the positioning terminal device 30 (S25), and complete | finishes a process.

  As described above, according to the radio positioning system 1, each base station device 10 transmits the reference signal packet at a timing based on the priority order BP. Therefore, even if a plurality of base station devices 10 are installed, the reference signal The occurrence of packet collision is prevented. That is, it is possible to install a plurality of base station devices 10 that function as reference station devices.

  Further, each base station apparatus 10 restricts transmission when a reference signal packet is received from another base station apparatus 10, so that collision of reference signal packets can be prevented more reliably.

  Furthermore, in the radio positioning system 1, the base station device 10 can function as an access point device.

  Next, specific contents of the BP and a determination method thereof will be described. In the following, an integer of 0 to 20 is used as BP, and BP0 is a value (highest value) indicating the highest priority, and the priority of reference signal transmission decreases as the value of BP increases. To do.

  BP is the coordinates of each base station device 10, the surrounding environment of each base station device 10 (the number of communicable base station devices 10 and the coordinates of these base station devices 10), the directivity of the antenna 11, and the terminal to be measured It is determined based on any one of the predicted coordinates of the apparatus 30, the result of positioning by the position determination unit 22 (positioning result), or a combination thereof. The BP is determined so that the same BP is not assigned to at least two adjacent base station apparatuses 10 and two base station apparatuses 10 that can communicate with each other. This will be specifically described below.

  FIG. 8 is a schematic block diagram illustrating functional blocks of the base station apparatus 10 and the positioning calculation server apparatus 20 according to the BP determination process. In addition, in the figure, like FIG. 3, only one base station apparatus 10 is described for simplicity, but each base station apparatus 10 is actually configured to include similar functional blocks.

  As shown in FIG. 8, the base station apparatus 10 includes a test control unit 56, a test signal transmission unit 57, and a test signal reception unit 58 in addition to the antenna 11 and the BP storage unit 52 shown in FIG. The Further, the positioning calculation server device 20 includes a positioning result information storage unit 23, a coordinate information storage unit 24, a communication distance information storage unit 25, an antenna radiation pattern information storage unit 26, in addition to the position determination unit 22 shown in FIG. The position information storage unit 27 and the BP calculation unit 28 are included.

  The positioning result information storage unit 23 stores positioning result information indicating the number of successful positionings by the positioning unit 22 and the number of failures for each base station device 10. The position determination unit 22 determines the position of the positioning terminal device 30 as described above. The position determination result (success or failure) for the base station apparatus 10 that has transmitted the reference signal packet every time the position determination is performed. Based on this, the positioning result information stored in the positioning result information storage unit 23 is updated.

  The coordinate information storage unit 24 includes positioning target area coordinate information that represents the shape and size of the positioning target area (room) in a predetermined coordinate system, and a base that represents the position of each base station device 10 in the coordinate system. Station station coordinate information. Each coordinate information is written in the coordinate information storage unit 24 by the user.

  The communication distance information storage unit 25 stores communication distance information indicating a communicable distance of each base station device 10. Usually, since the communicable distance is not different for each base station apparatus 10, the communication distance information storage unit 25 stores only one communication distance information. However, when the communicable distance is different for each base station apparatus 10, the communication distance information storage unit 25 desirably stores the communication distance information for each base station apparatus 10.

  The antenna radiation pattern information storage unit 26 stores antenna radiation pattern information indicating the radiation pattern (antenna directivity) of the antenna 11 provided in each base station apparatus 10. Usually, since the radiation pattern of the antenna 11 is not different for each antenna 11, the antenna radiation pattern information storage unit 26 stores only one piece of antenna radiation pattern information. However, when the radiation pattern of the antenna 11 is different for each antenna 11, the antenna radiation pattern information storage unit 26 desirably stores the antenna radiation pattern information for each base station device 10.

  In addition, each information memorize | stored in the coordinate information storage part 24, the communication distance information storage part 25, and the antenna radiation pattern information storage part 26 is good also as a user writing in the positioning calculation server apparatus 20, and each base station apparatus. 10 may be information stored for each device. In the latter case, each base station device 10 transmits each piece of information to the positioning calculation server device 20.

  The position information storage unit 27 stores position information of the terminal device to be measured, which is the position of the terminal device 30 to be measured expressed in the coordinate system. The measured terminal device position information may be written in the coordinate information storage unit 24 by the user. Alternatively, the position information storage unit 27 may store information representing the position of the positioning terminal device 30 determined by the position determination unit 22 in the past in the coordinate system as positioning terminal device position information. .

  The test control unit 56 instructs the test signal transmission unit 57 to wirelessly transmit a predetermined test signal in accordance with an instruction from the BP calculation unit 28 described later. The test signal transmission unit 57 wirelessly transmits the test signal using the antenna 11 in accordance with an instruction from the test control unit 56.

  The test signal receiving unit 58 receives the test signal transmitted from the other base station apparatus 10 and outputs it to the test control unit 56. The test control unit 56 determines the base station device 10 that is the transmission source of the test signal input from the test signal receiving unit 58, and determines that the base station device 10 and the base station device 10 can communicate with each other. . The test control unit 56 outputs the determination result thus obtained to the BP calculation unit 28.

  The BP calculation unit 28 includes positioning result information stored in the positioning result information storage unit 23, each coordinate information stored in the coordinate information storage unit 24, communication distance information stored in the communication distance information storage unit 25, and antenna radiation pattern. The antenna radiation pattern information stored in the information storage unit 26 and the position information stored in the position information storage unit 27 are acquired. Further, when trying to calculate BP, the BP calculation unit 28 instructs the test control unit 56 to wirelessly transmit a test signal, and acquires determination result information indicating a determination result input as a result. Then, the BP calculating unit 28 obtains positioning result information, positioning target area coordinate information, base station apparatus coordinate information, communication distance information, antenna radiation pattern information, measured terminal apparatus position information, and determination result information acquired in this way. BP of each base station apparatus 10 is calculated based on a part or all of the above, and the BP of each base station apparatus 10 is determined based on the calculation result.

  The calculation of BP by the BP calculation unit 28 will be specifically described with some examples.

  The first example is a calculation example of BP based on positioning target area coordinate information and base station apparatus coordinate information. FIG. 9 is an explanatory diagram for explaining this example. In the example shown in the figure, the positioning target area has a shape obtained by combining two rectangles, and has six vertices. The positioning target area coordinate information is composed of the coordinates of each vertex. Here, (0, 0), (0, 100), (120, 100), (120, 40), (200, 40), (200, 0).

  In one example, the BP calculation unit 28 determines the maximum side center position of the positioning target area based on the coordinates of each vertex. For example, in FIG. 9, since the maximum side in the drawing horizontal direction and the maximum side in the drawing vertical direction are the upper side and the upper side in the drawing, respectively, the maximum side center position that is the center is shown in FIG. Position A (100, 50). The BP calculation unit 28 calculates the BP of each base station apparatus 10 based on the position A and the position of each base station apparatus 10 indicated by the base station apparatus coordinate information. Specifically, the BP of each base station apparatus 10 is calculated so that a higher BP is assigned as the position A is closer.

  In another example, the BP calculation unit 28 determines a position that can be seen through every corner of the positioning target area based on the coordinates of each vertex. For example, the position B (120, 40) shown in FIG. 9 corresponds to this position. And BP calculation part 28 calculates BP of each base station apparatus 10 based on this position B and the position of each base station apparatus 10 shown by base station apparatus coordinate information. Specifically, the BP of each base station apparatus 10 is calculated so that a higher BP is assigned as the position B is closer.

  In yet another example, the BP calculation unit 28 calculates the proximity of each base station device 10 to the corner of the positioning target area, and the BP of each base station device 10 based on the calculated proximity. Is calculated. Specifically, the BP of each base station device 10 is calculated so that a higher BP is assigned as it is closer to the corner of the positioning target area. Alternatively, in communication, since it is important that radio waves can reach directly, that is, it is possible to see through, the BP calculation unit 28 advances BP based on the number of observable angles (corners) for each base station device 10. It is good to do.

  The second example is a calculation example of BP based on communication distance information and base station apparatus coordinate information. FIG. 10 is an explanatory diagram for explaining this example. The positioning target area in the example shown in the figure is the same as that in FIG. Each base station apparatus 10 is arranged as shown in FIG. 10, and the communicable distance of each base station apparatus 10 indicated by the communication distance information is 60. This communicable distance is set based on the results of simulation studies and past measured data.

  The BP calculation unit 28 uses the base station apparatus coordinate information to obtain the number of other base station apparatuses 10 within the range of the communicable distance 60 from the position of each base station apparatus 10. For example, since there are four other base station apparatuses 10 within the range of the communicable distance 60 from the base station apparatus 10-5 (indicated by a circle D5 in FIG. 10), the BP calculating unit 28 4 is acquired for the device 10-5. Similarly, since there is one other base station apparatus 10 within the range of the communicable distance 60 from the base station apparatus 10-7 (indicated by a circle D7 in FIG. 10), the BP calculating unit 28 1 is acquired for the station apparatus 10-7. Then, the BP calculation unit 28 calculates the BP of each base station device 10 based on the number of base station devices 10 thus acquired. Specifically, the BP of each base station apparatus 10 is calculated so that a higher BP is allocated as the number of acquired base station apparatuses 10 increases.

  The third example is a BP calculation example based on antenna radiation pattern information and base station apparatus coordinate information. FIG. 11 is an explanatory diagram for explaining this example. The positioning target area in the example shown in the figure is the same as that in FIGS. The arrangement of the base station apparatus 10 is the same as that in FIG.

  The BP calculating unit 28 uses the antenna radiation pattern information and the base station apparatus coordinate information to obtain the number of other base station apparatuses 10 within the reach of the radio wave radiated from the antenna 11 for each base station apparatus 10. To do. For example, since there is one other base station apparatus 10 within the reach of radio waves radiated from the antenna 11 of the base station apparatus 10-5 (indicated by the closed curve P5 in FIG. 10), the BP calculation unit 28 Acquires 1 for the base station apparatus 10-5. Similarly, since there are two other base station devices 10 within the reach of radio waves radiated from the antenna 11 of the base station device 10-7 (indicated by the closed curve P7 in FIG. 10), the BP calculating unit 28 acquires 2 for the base station apparatus 10-5.

  The fourth example is a calculation example of BP based on the determination result information. In this example, the BP calculation unit 28 acquires the number of other base station devices 10 that can communicate with each base station device 10 based on the determination result information. Then, the BP calculation unit 28 calculates the BP of each base station device 10 based on the acquired number of base station devices 10. Specifically, the BP of each base station apparatus 10 is calculated so that a higher BP is allocated as the number of acquired base station apparatuses 10 increases.

  The fifth example is a calculation example of BP based on the measured terminal apparatus position information and the base station apparatus coordinate information. In this example, the BP calculation unit 28 calculates the distance from the measured terminal device 30 for each base station device 10 based on the measured terminal device position information and the base station device coordinate information. Then, the BP calculating unit 28 calculates the BP of each base station device 10 based on the calculated distance. Specifically, the BP of each base station apparatus 10 is calculated so that a higher BP is assigned as the calculated distance is shorter.

  The sixth example is a calculation example of BP based on positioning result information. In this example, based on the positioning result information, the BP calculation unit 28 calculates, for each base station device 10, the rate at which each base station device 10 has been involved in the past as a reference station device, and based on the calculated rate. Thus, the BP of each base station apparatus 10 is calculated. Specifically, the BP of each base station apparatus 10 is calculated so that a higher BP is assigned as the calculated ratio is higher.

  The seventh example is a calculation example of BP by combining the above examples. In this example, the BP calculation unit 28 sums up the BP calculated in each of the above examples for each base station apparatus 10, normalizes the BP, and sets it as the BP of each base station apparatus 10. Note that the BP calculation unit 28 may calculate the total of the BPs calculated according to the above examples after predetermined weighting.

  When the BP calculated as described above has the same value between the two base station apparatuses 10 that can communicate with each other, the BP calculation unit 28 changes at least one of the BPs to the same value. It is desirable not to become.

  The BP calculation unit 28 writes the BP for each base station device 10 calculated as described above into the BP storage unit 52 of each base station device 10. Note that the BP calculation unit 28 does not perform calculation of BP and writing to the BP storage unit 52 only once, but appropriate timing such as periodic timing or timing when the arrangement of the base station apparatus 10 is changed. It is desirable to repeat this step. In particular, by repeatedly calculating the BP based on the determination result information and the positioning result information, when a radio wave shielding object is installed around the base station device 10 having a high BP from a certain point in time, or for a certain base. It becomes possible to update the BP appropriately when the performance of the station apparatus 10 is deteriorated.

  Finally, reference signal transmission at timing based on BP will be described again from a comprehensive point of view. FIG. 12 is an explanatory diagram for explaining a difference in reference signal transmission timing due to BP. FIG. 4A shows the reference signal transmission timing of the base station apparatus 10 whose BP is the highest value described above, and FIG. 5B shows the reference signal transmission timing of the base station apparatus 10 which is not the highest value. Yes.

  For example, it is assumed that the maximum value 0 of BP is assigned to the base station apparatus 10 installed in the middle of the positioning target area. After receiving the positioning signal packet, the base station apparatus 10 assigned the BP with the maximum value 0 transmits the reference signal packet in a reflective manner (FIG. 12 (a)). On the other hand, after receiving the positioning signal packet, the base station apparatus 10 to which the BP that is not the highest value is assigned waits for the reference signal packet within the time corresponding to the BP. When the reference signal packet is not received, the reference signal packet is transmitted (FIG. 12B). When the reference signal packet is received, the reference signal packet is not transmitted.

  In addition, there may be a case where the BP with the maximum value 0 is not assigned to any base station apparatus 10. Also in this case, each base station apparatus 10 that has received the positioning signal packet waits for the reference signal packet within the time corresponding to the BP. When the reference signal packet is not received, the reference signal packet is transmitted (FIG. 12B). When the reference signal packet is received, the reference signal packet is not transmitted.

  In any of these cases, there may be a base station apparatus 10 to which the same BP value is assigned. Therefore, in this embodiment, each base station apparatus 10 waits for a reference signal packet within a time corresponding to the BP, and further waits for a time based on a random value, and then transmits the reference signal packet.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the present invention is applied when the measured terminal apparatus 30 transmits a positioning signal. However, the present invention can also be applied when each base station apparatus 10 transmits a positioning signal. In this case, the position determination unit 22 receives the positioning signal transmission time and the reference signal reception time measured from each base station device 10 based on the clock of each base station device 10, and receives the measured positioning signal from the positioning terminal device 30. The reception time of each positioning signal measured based on the clock of the terminal device 30 is received. The position determination unit 22 calculates the positioning signal reception time difference between the base station apparatuses 10 based on the times received in this way as follows, and based on the calculated positioning signal reception time difference, the positioning terminal apparatus 30 Determine the position.

That is, the position determination unit 22 calculates the positioning signal reception time difference B _{m, n} between the base station apparatus 10-n and the base station apparatus 10-m (m ≠ n) as {(s _n −l _n ) −t. _ns } − {(s _m −l _m ) −t _ms } − (t _nr −t _mr ). However, the positioning signal transmission time for the base station apparatus 10-n is t _ns , the reference signal reception time is s _n , the reception signal of the positioning signal is t _nr , and the reference signal packet is transmitted to the base station apparatus 10-n. distance information indicating a distance between the base station apparatus 10 in units of time and l _n, the positioning signal transmission time of the base station apparatus 10-m t _ms, the same reference signal reception time s _m, the reception of the positioning signal time of t _mr, and l _m distance information indicating a distance between the base station apparatus 10 that has transmitted the base station apparatus 10-m and the reference signal packets in units of time. Thus, the present invention can also be applied to the case where each base station apparatus 10 transmits a positioning signal.

  Moreover, although the said embodiment demonstrated that the to-be-measured terminal device 30 was one, in fact, there are often a plurality of to-be-measured terminal devices 30. In such a case, the position information storage unit 27 stores the measured terminal apparatus position information for each measured terminal apparatus 30. The BP calculation unit 28 calculates the BP for each measured terminal device 30 based on the measured terminal device position information stored in the position information storage unit 27 for the measured terminal device 30, and the BP storage unit 52 also receives the measured BP storage unit 52. The BP is stored for each positioning terminal device 30. Then, the reference signal transmission unit 53 determines the positioning terminal device 30 that has transmitted the positioning signal, and determines the reference signal transmission timing based on the BP stored in the BP storage unit 52 for the positioning terminal device 30. .

  In the above embodiment, both the positioning signal transmission time and the reference signal reception time are transmitted together in one packet. However, they may be transmitted in separate packets.

  Moreover, in the said embodiment, although calculation of BP allocated to each base station apparatus 10 was performed by the positioning calculation server apparatus 20, it is good also as performing by any of the base station apparatuses 10. FIG. In this case, the base station apparatus 10 that has calculated the BP transmits the calculated BP to the positioning calculation server apparatus 20, and the positioning calculation server apparatus 20 transmits the received BP to the BP storage unit of the other base station apparatus 10. It is preferable to write to 52.

  Further, a program for realizing the functions of the base station device 10, the positioning calculation server device 20, and the measured terminal device 30 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is stored in the computer system. Each of the above processes may be performed by reading and executing.

  Here, the “computer system” may include an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.

  The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

  Furthermore, the “computer-readable recording medium” includes a volatile memory (for example, DRAM (DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Dynamic Random Access Memory)), etc., which hold programs for a certain period of time.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.

  Further, the program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve each function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

It is a system configuration figure of the radio positioning system concerning an embodiment of the invention. It is a hardware block diagram of the base station apparatus concerning embodiment of this invention. It is a schematic block diagram which shows the functional block of the base station apparatus, positioning calculation server apparatus, and positioning terminal device concerning embodiment of this invention. It is explanatory drawing for demonstrating the process of the position determination part concerning embodiment of this invention. It is a figure which shows the process sequence of the wireless positioning system concerning embodiment of this invention. It is a figure which shows the processing flow of the base station apparatus concerning embodiment of this invention. It is a figure which shows the processing flow of the positioning calculation server apparatus concerning embodiment of this invention. It is a schematic block diagram which shows the functional block of the base station apparatus and positioning calculation server apparatus concerning the BP determination process concerning embodiment of this invention. It is explanatory drawing for demonstrating the example of calculation of BP based on the position target area coordinate information and base station apparatus coordinate information concerning embodiment of this invention. It is explanatory drawing for demonstrating the example of calculation of BP based on the communication distance information and base station apparatus coordinate information concerning embodiment of this invention. It is explanatory drawing for demonstrating the example of calculation of BP based on the antenna radiation pattern information concerning embodiment of this invention, and base station apparatus coordinate information. It is explanatory drawing for demonstrating the difference in the reference signal transmission timing by BP concerning embodiment of this invention.

Explanation of symbols

1 wireless positioning system,
10 base station equipment,
11 Antenna,
12 Radio section,
13 Signal processor,
20 positioning calculation server device,
21 distance information storage unit,
22 Position determination unit,
23 positioning result information storage unit,
24 coordinate information storage unit,
25 communication distance information storage unit,
26 Antenna radiation pattern information storage unit,
27 position information storage unit,
28 BP calculation unit,
30 Positioned terminal device,
31 Positioning signal transmitter,
32 antenna,
40 network,
50 Positioning signal receiver,
51 Time transmitter,
52 BP storage unit,
53 reference signal transmitter,
54 Reference signal receiver,
55 Reference signal transmission limiter,
56 test controller,
57 test signal transmitter,
58 test signal receiver,
131 microcontroller,
132 storage media,
133 counter,
134 Baseband signal processing unit.

Claims (11)

A wireless positioning system that includes a plurality of base station devices and measures the position of a positioning object using at least a part of the plurality of base station devices ,
Before Symbol each base station apparatus,
Priority order storage means for storing the priority order of the reference signal transmission calculated by the priority order calculation means and assigned to the base station apparatus;
Positioning signal receiving means for receiving a positioning signal from the positioning object and acquiring the reception time based on a clock held by the base station device;
After receiving the positioning signal by the positioning signal receiving means, a reference signal transmitting means for transmitting the reference signal at a timing based on the priority order acquired from the priority order storage means;
Reference signal receiving means for receiving the reference signal transmitted by the other base station apparatus and acquiring the reception time based on the clock;
Including
The wireless positioning system
Coordinate information storage means for storing positioning target area coordinate information representing the shape of the positioning target area and base station apparatus coordinate information representing the position of each base station apparatus;
Based on the line-of-sight position relationship when the positioning target area is viewed from each base station apparatus obtained by referring to the positioning target area coordinate information and the base station apparatus coordinate information, the priority order for each base station apparatus The priority order calculating means for calculating
Position determining means for determining the position of the positioning object based on the reception time of the positioning signal and the reception time of the reference signal acquired in each base station device;
including,
A wireless positioning system characterized by that. The wireless positioning system according to claim 1,
The wireless positioning system
Position information storage means for storing position measurement object position information representing the position of the position determination object determined by the position determination means;
Including
The priority calculation means calculates a distance between the measured object and each base station apparatus based on the measured object position information and the base station apparatus coordinate information, and based on the calculated distance, each base station A wireless positioning system , wherein the priority order is calculated for a station device . In the radio positioning system according to claim 1 or 2 ,
The priority calculation unit, a radio positioning system, wherein the each base station apparatus based on the number of other base station apparatus capable of communicating, to calculate the priority for each base station apparatus. In radio positioning system according to any one of claims 1 to 3,
The wireless positioning system, wherein the priority order calculating means calculates the priority order for each base station apparatus based on an antenna radiation pattern of each base station apparatus . In the radio positioning system according to any one of claims 1 to 4 ,
The priority calculation unit, in a case where any of the respective base station apparatus has received the positioning signal, based on said ratio position determination by the position determination unit is completed, the priority for each of the base station apparatus A wireless positioning system characterized by calculating . The radio positioning system according to any one of claims 1 to 5 ,
Send and receive a predetermined test signal between the base station devices,
The wireless communication system according to claim 1, wherein the priority calculation means calculates the priority for each of the base station devices based on a communication status of transmitting / receiving the test signal . The radio positioning system according to any one of claims 1 to 6 ,
Each of the base station devices
Reference signal transmission restricting means for restricting transmission of the reference signal by the reference signal transmitting means when the reference signal is received by the reference signal receiving means;
including,
A wireless positioning system characterized by that. In the radio positioning system according to any one of claims 1 to 7 ,
Distance information acquisition means for acquiring distance information indicating a distance between the base station devices;
Including
The position determining means is configured to determine a reception time of the reference signal and the positioning signal acquired in each base station device and a distance between each base station device and the base station device that has transmitted the reference signal. And determining the position of the positioning object based on the distance information shown.
A wireless positioning system characterized by that. A base station device,
Priority order storage means for storing the priority order of the reference signal transmission calculated by the priority order calculation means and assigned to the base station apparatus;
Positioning signal receiving means for receiving a positioning signal from a positioning object and acquiring the reception time based on a clock held by the base station device;
A reference signal transmitting means for transmitting a reference signal at a timing based on the reception timing of the positioning signal by the positioning signal receiving means and the priority order obtained from the priority order storage means;
Coordinate information storage means for storing positioning target area coordinate information representing the shape of the positioning target area and base station apparatus coordinate information representing the positions of a plurality of base station apparatuses;
Based on the line-of-sight position relationship when the positioning target area is viewed from each base station apparatus obtained by referring to the positioning target area coordinate information and the base station apparatus coordinate information, the priority order for each base station apparatus The priority order calculating means for calculating
A base station apparatus comprising: A positioning method for measuring a position of a positioning object using a wireless positioning system including a plurality of base station devices,
The wireless positioning system is obtained by referring to positioning target area coordinate information representing the shape of the positioning target area and base station apparatus coordinate information representing the position of each base station apparatus, from the base station apparatus to the positioning target A priority calculation step for calculating and assigning a priority of reference signal transmission for each of the base station devices, based on a line-of-sight position relationship when the area is viewed;
Each base station apparatus receives a positioning signal from the object to be measured, and based on the clock held by the base station apparatus, acquires a reception time of the positioning signal;
Each base station apparatus transmits the reference signal at a timing based on the positioning signal reception timing in the positioning signal receiving step and the priority assigned to the base station apparatus in the priority calculation step. A reference signal transmission step;
Each base station apparatus receives the reference signal transmitted by the other base station apparatus, and obtains the reception time based on the clock,
A positioning method comprising: Includes a plurality of base stations, in a radio positioning system which measures the position of the positioning thereof using at least part of a base station apparatus of said plurality of a program for functioning the computer as before Kimoto Chikyoku device There ,
The computer,
Priority order storage means for storing the priority order of the reference signal transmission calculated by the priority order calculation means and assigned to the base station apparatus;
Positioning signal reception time acquisition means for acquiring a reception time of a positioning signal received from the positioning object based on a clock held by the base station device;
Reference signal transmission control means for causing the transmission means to transmit the reference signal at a timing based on the priority order acquired from the priority order storage means after the positioning signal is received .
A reference signal receiving means for acquiring a reception time of the reference signal received from another base station apparatus based on the clock;
Coordinate information storage means for storing positioning target area coordinate information representing the shape of the positioning target area and base station apparatus coordinate information representing the position of each base station apparatus, and
Based on the line-of-sight position relationship when the positioning target area is viewed from each base station apparatus obtained by referring to the positioning target area coordinate information and the base station apparatus coordinate information, the priority order for each base station apparatus The priority calculating means for calculating
Program to function as a.

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