JP6809925B2 - Beacon tracking system and method - Google Patents

Description

The present invention relates to a tracking beacon technique in which a radio signal intermittently transmitted from a beacon terminal is received by a receiving device to track the position of the beacon terminal.

Conventionally, as a beacon system that identifies the position of a beacon terminal, a beacon tracking system that tracks the position of a beacon terminal by receiving a radio signal intermittently transmitted from the beacon terminal by a receiver has been proposed (for example). , Non-Patent Document 1 etc.).
Such beacon tracking systems are becoming widely used due to lower hardware prices and the widespread use of low power wireless technologies such as BLE (Bluetooth Low Energy).

In this beacon tracking system, a beacon signal including a terminal ID is wirelessly transmitted from a beacon terminal at regular intervals. Since there is a one-to-one correspondence between the beacon terminal and the terminal ID, it is possible to easily identify which beacon terminal exists at which position. A wireless communication profile for transmitting a beacon signal can be selected according to the application and distance required for the beacon terminal. By adopting a good wireless communication profile, it is possible to handle long transmission distances with low power consumption. Therefore, for general tracking applications, BLE beacons having a medium level communication distance and low power consumption are used.

"Track your phone, wallet, keys & anything else with TrackR!", TrackR, Inc., https://buy.thetrackr.com/jp/ Shoichi Oshima et al., "Technology for reducing power consumption of wireless sensor terminals utilizing nanowatt-class wireless circuits", NTT, NTT Technology Journal, 2014.11.

FIG. 6 is a configuration example of a conventional beacon tracking system. FIG. 7 is an example of transmitting a conventional beacon signal. Since the beacon terminal is small, it can be attached to a key, bag, pet, etc., and as shown in FIGS. 6 and 7, it is lost by continuously transmitting a beacon signal from an omnidirectional antenna in all directions at regular intervals. Tracking is possible when you get lost or get lost.

However, such a conventional beacon terminal always transmits a beacon signal at a fixed interval t, and the receiving device is based on the latest received beacon signal, for example, in response to the arrival of a position specifying timing consisting of a fixed cycle T. The position of the beacon terminal is confirmed. Therefore, since the beacon terminal requires a certain amount of electric power, the battery life is relatively short, and there is a problem that the battery or the beacon terminal itself needs to be replaced within one year depending on the usage.

The present invention is for solving such a problem, and an object of the present invention is to provide a tracking beacon technology capable of reducing power consumption in a beacon terminal.

In order to achieve such an object, the beacon tracking system according to the present invention is attached to a tracking target and wirelessly transmits a beacon signal including a terminal ID unique to itself, and the beacon signal received. A beacon tracking system including a receiving device that acquires beacon information for identifying the existing position of the target based on the above, and the receiving device activates the beacon terminal in response to the arrival of the position specifying timing. The beacon terminal includes a trigger transmission unit that transmits the trigger signal of the device side from the device side antenna and a beacon receiving unit that acquires the beacon information based on the beacon signal from the beacon terminal received by the device side antenna. , A trigger receiving unit that generates power based on the trigger signal from the receiving device received by the terminal antenna and outputs a trigger detection signal according to an increase in the obtained generated voltage, and the trigger receiving unit based on the trigger detection signal. It includes a beacon transmission unit that transmits a beacon signal including a terminal ID from the terminal side antenna by ultra-low power UWB (Ultra Wide Band) wireless communication.

Also, the beacon tracking system according to the present invention, the receiving apparatus, wherein the apparatus antenna provided with a plurality of apparatus-side individual antennas arranged in different directions, the trigger transmitting section with these apparatus individually antenna The beacon terminal further includes a reception control unit that switches between the beacon receiving unit and the beacon receiving unit, and the beacon terminal includes a plurality of terminal-side individual antennas arranged in different directions as the terminal-side antenna, and each terminal-side individual antenna has a plurality of individual antennas. wherein each comprise a beacon unit comprising a trigger receiver and beacon transmission unit, that provides further a beacon control unit which activates any one selectively of these beacons units.

Further, in one configuration example of the beacon tracking system according to the present invention, the device-side antenna is a directional antenna having a constant directivity, and the terminal-side antenna is from a directional antenna having a constant directivity. It will be.

Further, in one configuration example of the beacon tracking system according to the present invention, the device-side antenna has a directivity for transmitting the trigger signal in a first fixed direction, and the beacon signal is transmitted to the first device. It is composed of a device-side receiving antenna having a directivity of receiving from a certain direction of 1, and the terminal-side antenna includes a terminal-side transmitting antenna having a directivity to receive the trigger signal from a second fixed direction and the beacon signal. the Ru der made of a terminal-side receiving antenna having directivity for transmitting said to a second fixed direction.

Further, the beacon terminal according to the present invention is a beacon terminal used in any of the beacon tracking systems described above.
Further, the receiving device according to the present invention is a receiving device used in any of the beacon tracking systems described above.

Further, in the beacon tracking method according to the present invention, a beacon terminal attached to a tracking target and wirelessly transmitting a beacon signal including a terminal ID unique to itself and an existing position of the target based on the received beacon signal are determined. This is a beacon tracking method used in a beacon tracking system including a receiving device that acquires beacon information for identification, and a trigger transmitting unit of the receiving device activates the beacon terminal in response to the arrival of a position specifying timing. A trigger transmission step of transmitting a trigger signal from the device side antenna and a trigger receiving unit of the beacon terminal generate power based on the trigger signal received by the terminal side antenna from the receiving device, and the obtained power generation A trigger reception step that outputs a trigger detection signal when the voltage reaches a reference voltage, and a beacon transmission unit of the beacon terminal transmits a beacon signal including the terminal ID based on the trigger detection signal to an ultra-low power UWB ( Ultra Wide Band) The beacon transmission step transmitted from the terminal side antenna in wireless communication and the beacon receiving unit of the receiving device acquire the beacon information based on the beacon signal from the beacon terminal received by the device side antenna. Beacon reception step, and the reception control unit of the receiving device switches between a plurality of device-side individual antennas provided as the device-side antenna and arranged in different directions, the trigger transmitting unit and the beacon receiving unit. The control step and the beacon control unit of the beacon terminal include the trigger receiving unit and the beacon transmitting unit provided for each of a plurality of terminal-side individual antennas arranged in different directions provided as the terminal-side antenna. It includes a beacon control step that selectively activates any one of the beacon units .

According to the present invention, the beacon signal is returned from the beacon terminal only when the trigger signal from the receiving device is detected. Therefore, it is possible to avoid the transmission of unnecessary beacon signals that occur when the beacon signals are transmitted at regular intervals as in the conventional case, and it is possible to reduce the power consumption of the beacon terminal. At this time, since power is generated based on the received trigger signal and the beacon signal is transmitted according to the increase in the obtained generated voltage, it is not necessary to use the power consumption of a battery or the like to detect the trigger signal. Therefore, it is possible to transmit the beacon signal at an arbitrary timing without increasing the power consumption of the beacon terminal.

It is a block diagram which shows the structure of the beacon tracking system which concerns on 1st Embodiment. It is a sequence diagram which shows the transmission of a trigger signal and a beacon signal. It is a block diagram which shows the structure of the beacon tracking system which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the beacon terminal which concerns on 3rd Embodiment. It is a block diagram which shows the structure of the receiving apparatus which concerns on 3rd Embodiment. This is a configuration example of a conventional beacon tracking system. This is a conventional beacon signal transmission example.

Next, an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
First, the beacon tracking system 1 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a beacon tracking system according to the first embodiment.
The beacon tracking system 1 is composed of a beacon terminal 10 and a receiving device 20, and receives a beacon signal BC transmitted from the beacon terminal 10 by the receiving device 20, and is a target to which the beacon terminal 10 is attached. It is a system that determines the position.
According to the present invention, the beacon signal BC is transmitted from the beacon terminal 10 by the directional antenna in response to the trigger signal TR transmitted from the receiving device 20 by the directional antenna.

[Beacon terminal]
The beacon terminal 10 is a terminal in which an electronic circuit and a small antenna are composed of an electronic medium incorporated in a case such as plastic as a whole, and is attached to a tracking target to transmit a beacon signal BC including a preset terminal ID. It is a device.
As shown in FIG. 1, the beacon terminal 10 is provided with a trigger receiving unit 11, a beacon transmitting unit 12, and a terminal-side antenna 13 as main functional units.

The trigger receiving unit 11 is a circuit unit that receives the trigger signal TR from the receiving device 20 via the terminal antenna 13 and outputs a transmission instruction signal Tx instructing the transmission of the beacon signal BC, and serves as a main circuit unit. , The tank circuit TUN and the comparison circuit CMP are provided.

The tank circuit TUN is composed of a capacitance element C having a resonance frequency tuned to the trigger signal TR and an induction element L connected in parallel, and has a function of generating power based on the received trigger signal TR and outputting the obtained generated voltage Vp. doing.
The comparison circuit CMP operates at the generated voltage Vp output from the tank circuit TUN, and when the generated voltage Vp reaches the reference voltage Vref, has a function of outputting a trigger detection signal DET instructing the transmission of the beacon signal BC. Have.

The beacon transmitting unit 12 (nWTX) is composed of a so-called nanowatt-class ultra-low power UWB (Ultra Wide Band) wireless transmission circuit having extremely low power consumption, and responds to the trigger detection signal DET output from the trigger receiving unit 11. It has a function of wirelessly transmitting a beacon signal BC including a preset terminal ID from the terminal side antenna 13. Regarding the ultra-low power UWB wireless transmission circuit, for example, the terminal ID is driven by driving the ring oscillator with the power generated by the vibration sensor or the solar cell by using the low power consumption technology described in Non-Patent Document 2. It may be realized by a circuit that transmits a beacon signal BC including.

The terminal-side antenna 13 has directivity in a certain direction and is an antenna for exchanging the trigger signal TR and the beacon signal BC with the receiving device 20. In the present embodiment, since the terminal side antenna 13 is shared by the trigger receiving unit 11 and the beacon transmitting unit 12, the same signal frequency is used in the trigger signal TR and the beacon signal BC.

[Receiver]
The receiving device 20 is composed of an information processing terminal having a wireless communication function such as a PC or a smartphone as a whole, receives a beacon signal BC from a beacon terminal 10 mounted on a tracking target, and determines the radio wave reception strength of the beacon signal BC. This is a terminal device that determines the position of the beacon terminal 10 based on the terminal ID included in the beacon signal BC.
As shown in FIG. 1, the receiving device 20 is provided with a trigger transmitting unit 21, a beacon receiving unit 22, and a device-side antenna 23 as main circuit units.

The trigger transmission unit 21 activates the beacon terminal 10 in response to the arrival of a position specification timing such as a fixed transmission interval or a predetermined operation input, which indicates a timing for specifying the position of the target on which the beacon terminal 10 is mounted. It has a function of generating a trigger signal TR of the above and transmitting it from the device side antenna 23. As the trigger signal TR, a pulse signal or a sine wave signal having a predetermined signal frequency may be used.

The beacon receiving unit 22 is composed of a general UWB wireless receiving circuit, receives the beacon signal BC transmitted from the beacon terminal 10 via the device side antenna 23, and uses the radio wave reception strength and the beacon signal BC related to the beacon signal BC. It has a function of acquiring beacon information for specifying the position of the beacon terminal 10, such as the included terminal ID.

The device-side antenna 23 has directivity in a certain direction and is an antenna for exchanging the trigger signal TR and the beacon signal BC with the beacon terminal 10. In the present embodiment, since the device-side antenna 23 is shared by the trigger transmitting unit 21 and the beacon receiving unit 22, the same signal frequency is used in the trigger signal TR and the beacon signal BC.

[Operation of the first embodiment]
Next, the operation of the beacon tracking system 1 according to the present embodiment will be described with reference to FIG. FIG. 2 is a sequence diagram showing transmission of a trigger signal and a beacon signal.

First, in the receiving device 20, the trigger transmitting unit 21 generates a trigger signal TR in the trigger transmitting unit 21 according to the arrival of the confirmation timing of the terminal position consisting of a preset constant cycle T (step 100), and the device side. Transmission from the antenna 23 in a certain direction (step 101).

In the beacon terminal 10, the trigger receiving unit 11 generates electricity in the tank circuit TUN based on the trigger signal TR received by the terminal antenna 13, and obtains the generated voltage Vp. At this time, when the trigger signal TR is a signal transmitted from the receiving device 20 located in a certain direction of the terminal antenna 13, the radio wave reception intensity of the trigger signal TR is increased. Therefore, when the generated voltage Vp rises significantly and the generated voltage Vp reaches the reference voltage Vref, the trigger detection signal DET is output from the comparison circuit CMP (step 102).

The beacon transmitting unit 12 generates a beacon signal BC including a preset terminal ID in response to the trigger detection signal DET from the trigger receiving unit 11, and transmits it from the device-side antenna 23 in a certain direction (step 103). ..

In the receiving device 20, the beacon receiving unit 22 processes the beacon signal BC received by the device-side antenna 23, and acquires the radio wave reception intensity related to the beacon signal BC and the terminal ID included in the beacon signal BC. At this time, when the beacon signal BC is a signal transmitted from the beacon terminal 10 located in a certain direction of the device-side antenna 23, the radio wave reception intensity of the beacon signal BC is increased. Therefore, as the beacon information required for specifying the terminal position from the beacon signal BC, it is possible to obtain a sufficiently large radio wave reception intensity and an accurate terminal ID for identifying the bin marriage terminal.

After that, the receiving device 20 stops the transmission of the trigger signal TR until a new confirmation timing based on the fixed cycle T arrives, and transmits the trigger signal TR in response to the arrival of the new confirmation timing (step 110) (step 111). ). After that, steps 112 to 114 similar to steps 102 to 104 described above are repeatedly executed, and new beacon information is acquired based on the new beacon signal BC transmitted from the beacon terminal 10.

[Effect of the first embodiment]
As described above, in the present embodiment, in the receiving device 20, the trigger transmitting unit 21 transmits a trigger signal TR for activating the beacon terminal 10 from the device side antenna 23 in response to the arrival of the position specifying timing. The beacon receiving unit 22 acquires beacon information based on the beacon signal BC from the beacon terminal 10 received by the device side antenna 23, and the trigger receiving unit 11 receives the beacon information by the terminal side antenna 13 in the beacon terminal 10. Power is generated based on the trigger signal TR from 20, and the trigger detection signal DET is output according to the increase in the obtained generated voltage Vp. The beacon transmission unit 12 is a beacon signal including the terminal ID based on the trigger detection signal DET. The BC is transmitted from the terminal side antenna 13 by ultra-low power UWB wireless communication.

As a result, the beacon signal BC is returned from the beacon terminal 10 only when the trigger signal TR from the receiving device 20 is detected. Therefore, it is possible to avoid the transmission of unnecessary beacon signals that occur when the beacon signals are transmitted at regular intervals as in the conventional case, and it is possible to reduce the power consumption of the beacon terminal 10. At this time, power is generated based on the received trigger signal TR, and the beacon signal BC is transmitted according to the increase in the obtained generated voltage Vp. Therefore, the power consumption of the battery or the like is used to detect the trigger signal TR. No need. Therefore, it is possible to transmit the beacon signal BC at an arbitrary timing without increasing the power consumption of the beacon terminal 10.

Further, in the present embodiment, the device-side antenna 23 may be provided with a directional antenna having a certain directivity, and the terminal-side antenna 13 may be provided with a directional antenna having a certain directivity.
As a result, the exchange of the trigger signal TR and the beacon signal BC between the receiving device 20 and the beacon terminal 10 can be limited to a certain direction. As a result, it is possible to improve the accuracy of identifying the position of the beacon terminal 10 as compared with the case of using an omnidirectional antenna, and it is possible to limit the beacon terminal 10 activated by the trigger signal TR, and the beacon terminal can be limited. It is possible to further reduce the power consumption at 10.

[Second Embodiment]
Next, the beacon tracking system 1 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing a configuration of the beacon tracking system according to the second embodiment.

In the first embodiment, when the beacon terminal 10 receives the trigger signal TR and transmits the beacon signal BC, one terminal side antenna 13 is shared, and the receiving device 20 transmits the trigger signal TR and the beacon signal. A case where one device-side antenna 23 is shared at the time of BC reception has been described as an example. According to this configuration, when one terminal side antenna 13 is shared and one device side antenna 23 is shared, it is necessary to make the signal frequencies of the trigger signal TR and the beacon signal BC uniform.

In the present embodiment, as shown in FIG. 3, in the beacon terminal 10, the terminal side receiving antenna 13R used for receiving the trigger signal TR and the terminal side transmitting antenna 13T used for transmitting the beacon signal BC are separately provided. In the receiving device 20, the device-side transmitting antenna 23T used for transmitting the trigger signal TR and the device-side receiving antenna 23R used for receiving the beacon signal BC are separately provided.

As a result, the transmitting antennas 13T and 23T and the receiving antennas 13R and 23R are separate, so that different signal frequencies can be used for the trigger signal TR and the beacon signal BC. Therefore, a higher signal frequency can be used as the trigger signal TR as compared with the beacon signal BC. As a result, the reachable range of the trigger signal TR can be expanded, and the position specifying range of the beacon terminal 10 can be expanded. Further, the antenna size used for transmitting and receiving the trigger signal TR can be reduced, and in particular, the increase in the terminal size of the beacon terminal 10 can be suppressed. As in the first embodiment, directional antennas may be used as the transmitting antennas 13T and 23T and the receiving antennas 13R and 23R.

[Third Embodiment]
Next, the beacon tracking system 1 according to the present embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a block diagram showing a configuration of a beacon terminal according to a third embodiment. FIG. 5 is a block diagram showing a configuration of the receiving device according to the third embodiment.

In the first embodiment, the direction in which the trigger signal TR and the beacon signal BC are transmitted / received is restricted by using a directional antenna as the terminal side antenna 13 of the beacon terminal 10 and the device side antenna 23 of the receiving device 20. explained.
In the present embodiment, a case of switching the direction of transmitting and receiving the trigger signal TR and the beacon signal BC will be described. In the following, a case of switching to any of the three directions will be described as an example, but the number of directions is not limited to the three directions, and may be two directions or four or more directions.

As shown in FIG. 4, the beacon terminal 10 according to the present embodiment includes a plurality of terminal-side individual antennas 13A, 13B, 13C arranged in different directions as terminal-side antennas, and these terminal-side individual antennas 13A. , 13B, 13C are each provided with beacon units 10A, 10B, 10C including a trigger receiving unit 11 and a beacon transmitting unit 12, respectively, and a beacon that selectively activates any one of these beacon units 10A, 10B, 10C. A control unit 14 is further provided.

As a result, in the direction in which the corresponding terminal-side individual antenna among the terminal-side individual antennas 13A, 13B, 13C is arranged by any one of the beacon units 10A, 10B, 10C selected by the beacon control unit 14. The trigger signal TR is received and the beacon signal BC is transmitted. The method of selecting the beacon units 10A, 10B, and 10C in the beacon control unit 14 may be selected based on, for example, a preset schedule, or may be randomly selected.

As shown in FIG. 5, the receiving device 20 according to the present embodiment includes a plurality of device-side individual antennas 23A, 23B, and 23C arranged in different directions as device-side antennas, and these device-side individual antennas 23A. , 23B, 23C, and a reception control unit 24 for switching between the trigger transmission unit 21 and the beacon reception unit 22.

As a result, the trigger signal TR is transmitted and the beacon signal BC is received in the direction in which one of the device-side individual antennas 23A, 23B, and 23C selected by the reception control unit 24 is arranged. The method of selecting the device-side individual antennas 23A, 23B, and 23C in the reception control unit 24 may be selected based on, for example, a preset schedule, or may be randomly selected.

Therefore, the exchange of the trigger signal TR and the beacon signal BC between the receiving device 20 and the beacon terminal 10 can be selected from one of a plurality of directions. Compared with the case where the trigger signal TR and the beacon signal BC are exchanged only in one direction, it is possible to expand the position specifying range without lowering the accuracy of specifying the position of the beacon terminal 10.

[Extension of Embodiment]
Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the structure and details of the present invention within the scope of the present invention. In addition, each embodiment can be implemented in any combination within a consistent range.

1 ... Beacon tracking system, 10 ... Beacon terminal, 10A, 10B, 10C ... Beacon unit, 11 ... Trigger receiving unit, 12 ... Beacon transmitting unit, 13 ... Terminal side antenna, 13A, 13B, 13C ... Terminal side individual antenna, 14 ... terminal control unit, 20 ... receiver, 21 ... trigger transmitter, 22 ... beacon receiver, 23 ... device side antenna, 23A, 23B, 23C ... device side individual antenna, TUN ... tank circuit, CMP ... comparison circuit, C ... Capacitive element, L ... Induction element, Vp ... Power generation voltage, Vref ... Reference voltage, DET ... Trigger detection signal, TR ... Trigger signal, BC ... Beacon signal.

Claims (6)

A beacon terminal that is attached to the tracking target and wirelessly transmits a beacon signal including a terminal ID unique to itself, and a receiving device that acquires beacon information for identifying the existence position of the target based on the received beacon signal. It is a beacon tracking system equipped with
The receiving device is
A trigger transmitter that transmits a trigger signal for activating the beacon terminal from the device-side antenna in response to the arrival of the position identification timing, and
A beacon receiving unit that acquires the beacon information based on the beacon signal from the beacon terminal received by the device-side antenna is provided.
The beacon terminal is
A trigger receiving unit that generates electricity based on the trigger signal from the receiving device received by the terminal antenna and outputs a trigger detection signal according to an increase in the obtained generated voltage.
A beacon transmission unit that transmits a beacon signal including the terminal ID based on the trigger detection signal from the terminal side antenna by ultra-low power UWB (Ultra Wide Band) wireless communication is provided .
The receiving device is
As the device-side antenna, a plurality of device-side individual antennas arranged in different directions are provided, and a reception control unit for switching between these device-side individual antennas, the trigger transmission unit, and the beacon reception unit is further provided.
The beacon terminal is
As the terminal-side antenna, a plurality of terminal-side individual antennas arranged in different directions are provided, and each terminal-side individual antenna is provided with a beacon unit including the trigger receiving unit and the beacon transmitting unit, and these beacon units are provided. A beacon tracking system characterized by further including a beacon control unit that selectively activates any one of the above . In the beacon tracking system according to claim 1,
The device-side antenna is composed of a directional antenna having a certain directivity.
The terminal-side antenna is a beacon tracking system characterized in that it is composed of a directional antenna having a certain directivity. In the beacon tracking system according to claim 2.
The device-side antenna includes a device-side transmitting antenna having a directivity to transmit the trigger signal in the first fixed direction, and a device-side receiving antenna having a directivity to receive the beacon signal from the first fixed direction. Consists of
The terminal-side antenna includes a terminal-side transmitting antenna having a directivity of receiving the trigger signal from the second fixed direction, and a terminal-side receiving antenna having a directivity of transmitting the beacon signal in the second fixed direction. Beacon tracking system characterized by consisting of. A beacon terminal used in the beacon tracking system according to any one of claims 1 to 3 . The receiving device used in the beacon tracking system according to any one of claims 1 to 3 . A beacon terminal that is attached to the tracking target and wirelessly transmits a beacon signal including a terminal ID unique to itself, and a receiving device that acquires beacon information for identifying the existence position of the target based on the received beacon signal. It is a beacon tracking method used in a beacon tracking system including
A trigger transmission step in which the trigger transmission unit of the receiving device transmits a trigger signal for activating the beacon terminal from the device side antenna in response to the arrival of the position identification timing.
Trigger reception in which the trigger receiving unit of the beacon terminal generates power based on the trigger signal from the receiving device received by the terminal antenna, and outputs a trigger detection signal when the obtained generated voltage reaches the reference voltage. Steps and
A beacon transmission step in which the beacon transmission unit of the beacon terminal transmits a beacon signal including the terminal ID based on the trigger detection signal from the terminal side antenna by ultra-low power UWB (Ultra Wide Band) wireless communication.
A beacon receiving step in which the beacon receiving unit of the receiving device acquires the beacon information based on the beacon signal from the beacon terminal received by the device-side antenna .
A reception control step in which the reception control unit of the reception device switches between a plurality of individual device-side antennas provided as the device-side antenna and arranged in different directions, the trigger transmission unit and the beacon reception unit.
Which of the beacon units including the trigger receiving unit and the beacon transmitting unit is provided for each of a plurality of terminal-side individual antennas arranged in different directions and provided with the beacon control unit of the beacon terminal as the terminal-side antenna. A beacon tracking method comprising: a beacon control step for selectively activating one of them.

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