Communication method

Abstract

A communication method includes: a carrier sensing step (S10) performing carrier sensing at each predetermined period; a transmission step (S11) transmitting first data including the ID information of its own wireless electronic tag to the wireless access point when no signal transmitted from another wireless electronic tag to the wireless access point is detected during the carrier sensing and the transmission is not in a stopped state; an instruction interpretation step (S12) detecting a signal during the carrier sensing and, if the signal is not transmitted from another wireless electronic tag to the wireless access point, interpreting the detected signal as a signal transmitted from the wireless access point and including an instruction in the signal; and a frequency changing step (S13) changing the radio frequency of a signal transmitted by its own wireless electronic tag when the signal is interpreted as including an instruction for indicating a frequency change.

Description

Technical Field

[0001] This disclosure relates to communication methods and wireless electronic tags, and more particularly to communication methods for active wireless electronic tags, communication methods for wireless access points that receive radio waves from active wireless electronic tags, and active wireless electronic tags themselves. Background Technology

[0002] There are wireless electronic tags attached to goods to track their location. These tags are also known as electronic tags, IC (Integrated Circuit) tags, wireless IC tags, contactless IC tags, and RFID (Radio Frequency Identification) tags. Furthermore, wireless electronic tags can be passive or active. Passive tags use electricity from an external device to emit radio waves, while active tags are powered by an internal battery and emit radio waves autonomously.

[0003] For example, Patent Document 1 discloses a system capable of tracking containers using active wireless electronic tags. Accordingly, Patent Document 1 discloses a system capable of real-time wireless tracking within a defined, restricted area.

[0004] (Existing technical literature)

[0005] (Patent Documents)

[0006] Patent Document 1: Japanese Patent Application Publication No. 2004-529049

[0007] However, the frequencies available for active wireless electronic tags vary by region. For example, in Japan, the available frequency is 920MHz. In China, the available frequency is, for example, 830MHz, and in Europe, it is 868MHz. Furthermore, in the United States, the available frequency is 915MHz.

[0008] In other words, when tracking across regions with different available frequencies in wireless electronic tags, the frequency needs to be changed.

[0009] Furthermore, since wireless electronic tags used for tracking and other purposes are mostly expensive, cheaper wireless electronic tags that lack data reception capabilities are used. In other words, cheaper wireless electronic tags have the problem of not being able to change their initially set frequency. Summary of the Invention

[0010] In view of the above circumstances, the present disclosure aims to provide a communication method and a wireless electronic tag capable of frequency changing for an active wireless electronic tag that does not have a unit for receiving data.

[0011] One aspect of the communication method disclosed herein is a communication method performed by one of the multiple wireless electronic tags in a communication system comprising a wireless access point and multiple wireless electronic tags. The communication method includes: a carrier sensing step, performing carrier sensing at each predetermined period; a transmission step, in which, during the execution of the carrier sensing, no signal is detected being transmitted to the wireless access point from a wireless electronic tag different from the one wireless electronic tag, and the transmission is not in a stopped state, transmitting first data to the wireless access point, the first data including information for uniquely identifying the one wireless electronic tag, i.e., ID information; an instruction interpretation step, in which, during the execution of the carrier sensing, a signal is detected, and if the signal is not transmitted to the wireless access point from a wireless electronic tag different from the one wireless electronic tag, the detected signal is interpreted as a signal transmitted from the wireless access point, and an instruction included in the signal transmitted from the wireless access point is interpreted; and a frequency changing step, in which, when the instruction interpretation step interprets the signal as including an instruction for indicating a frequency change, the radio frequency of the signal transmitted by the one wireless electronic tag is changed.

[0012] Accordingly, by utilizing carrier sensing functionality in an active wireless electronic tag that does not have a unit for receiving data, it is possible to interpret instructions sent by a wireless access point, thereby enabling the change of the frequency used by the wireless electronic tag.

[0013] Here, for example, in the transmission step, if the instruction interpretation step interprets the signal as including an instruction to stop transmission and change the frequency, and no signal transmitted from the different wireless electronic tags to the wireless access point is detected during the carrier sensing, second data is transmitted to the wireless access point, the second data being data added to the first data indicating that the instruction has been received. In the frequency changing step, if the instruction interpretation step interprets the signal as including an instruction to stop transmission and change the frequency, after the second data is transmitted, the radio frequency of the signal transmitted by the one wireless electronic tag is changed. The communication method further includes a control step in which, after the second data is transmitted in the transmission step, the execution of the transmission step is stopped only until the instruction interpretation step interprets the signal transmitted from the wireless access point detected during the carrier sensing as including an instruction to resume transmission.

[0014] Therefore, since the carrier sensing function can be used in the wireless electronic tag to interpret the instructions sent by the wireless access point, it is possible to change the frequency used by the wireless electronic tag and stop the transmission of signals.

[0015] Furthermore, for example, in the transmission step, if the instruction interpretation step interprets the signal as including an instruction to stop transmission, and no signal transmitted from the different wireless electronic tags to the wireless access point is detected during the execution of the carrier sensing, second data is transmitted to the wireless access point, the second data being data added to the first data indicating that the instruction has been received. The communication method further includes a control step in which, after the second data is transmitted in the transmission step, only the execution of the transmission step is stopped.

[0016] Therefore, since the wireless electronic tag can interpret the instructions sent by the wireless access point using the carrier sensing function, it is possible to stop the signal transmission of the wireless electronic tag.

[0017] Furthermore, for example, in the frequency change step, if the instruction interpretation step interprets the signal as including an instruction to indicate a frequency change, the radio frequency of the signal transmitted by the one wireless electronic tag is changed; and in the control step, when the radio frequency of the signal transmitted by the one wireless electronic tag is changed in the frequency change step, the execution of the transmission step is restarted.

[0018] Therefore, since the wireless electronic tag can use carrier sensing to interpret the instructions sent by the wireless access point, it is possible to change the frequency used by the wireless electronic tag and restart the signal transmission that has stopped.

[0019] Furthermore, for example, the information indicating that the instruction has been received is an ACK message, i.e., an Acknowledgement message.

[0020] Furthermore, for example, the carrier sensing step may include the following steps: a strength calculation step, which calculates the strength of the signal received during the execution of the carrier sensing; a first detection step, which determines that a signal transmitted to the wireless access point by a wireless electronic tag different from the wireless electronic tag is detected during a period when the first averaged strength exceeds a first threshold, wherein the first averaged strength is obtained by dividing and averaging the strength calculated in the strength calculation step by a first period; and a second detection step, which determines that the detected signal is not a signal transmitted to the wireless access point by a wireless electronic tag different from the wireless electronic tag by judging a pattern consisting of the number of times the second averaged strength exceeds a second threshold and the number of times it falls below the second threshold, wherein the second averaged strength is obtained by dividing and averaging the strength calculated in the strength calculation step by a second period shorter than the first period.

[0021] Accordingly, wireless electronic tags can utilize carrier sensing capabilities to enable simultaneous carrier sensing of normal data and carrier sensing of data used to interpret instructions sent by the wireless access point.

[0022] Furthermore, for example, in the carrier sensing step, the first carrier sensing step and the second carrier sensing step may be executed alternately. The first carrier sensing step includes the following steps: a strength calculation step, which calculates the strength of the signal received during the execution of the carrier sensing; and a first detection step, which determines that a signal transmitted to the wireless access point by a wireless electronic tag different from the first wireless electronic tag is detected during a period when the first averaged strength exceeds a first threshold. The first averaged strength is obtained by dividing the strength calculated in the strength calculation step into a first period and averaging it. The second carrier sensing step includes the following steps: a strength calculation step, which calculates the strength of the signal received during the carrier sensing; and a second detection step, which determines that the detected signal is not a signal sent to the wireless access point by a wireless electronic tag different from the first wireless electronic tag by judging the pattern consisting of the number of times the second averaged strength exceeds a second threshold and the number of times the second averaged strength is below the second threshold. The second averaged strength is obtained by dividing and averaging the strength calculated in the strength calculation step by a second period shorter than the first period.

[0023] Accordingly, wireless electronic tags can utilize carrier sensing capabilities to alternate between normal carrier sensing and carrier sensing used to interpret instructions sent by the wireless access point.

[0024] Furthermore, for example, in the instruction interpretation step, the instructions included in the signal sent from the wireless access point can be interpreted by a combination of the number of times the second average intensity of the pattern determined in the second detection step exceeds the second threshold and the number of times it falls below the second threshold.

[0025] Furthermore, one embodiment of the communication method disclosed herein is a communication method performed by a wireless access point in a communication system comprising a wireless access point and a plurality of wireless electronic tags. The communication method includes: an ID information collection step, collecting ID information, which is information that uniquely identifies each of the plurality of wireless electronic tags; a signal transmission step, broadcasting, for each of the plurality of wireless electronic tags, a signal including an instruction to change a first frequency currently used by the plurality of wireless electronic tags to a second frequency at each predetermined interval; and a signal stopping step, stopping the broadcasting of the signal including the instruction upon confirming that information indicating receipt of the instruction has been received from each of the plurality of wireless electronic tags.

[0026] Accordingly, the wireless access point can issue instructions to multiple wireless electronic tags under its management, that is, it can issue instructions to multiple active wireless electronic tags that do not have a unit for receiving data, thereby enabling the change of the frequency used by the wireless electronic tag.

[0027] Here, for example, the communication method may further include: an identification step, which identifies the movement of the plurality of wireless electronic tags toward an area where the second frequency is required, thereby identifying that the plurality of wireless electronic tags have begun to move toward the area, wherein the second frequency is a frequency different from the first frequency currently used by the plurality of wireless electronic tags; and a confirmation step, which confirms that the plurality of wireless electronic tags have entered the area. In the signal transmission step, when the identification step identifies that the plurality of wireless electronic tags have begun to move toward the area, an instruction is given to the plurality of wireless electronic tags to change the first frequency currently used by the plurality of wireless electronic tags to the second frequency, and a signal including an instruction to stop transmission is broadcast to the plurality of wireless electronic tags at each predetermined interval. Furthermore, when the confirmation step confirms that the plurality of wireless electronic tags have entered the area, a signal including an instruction to resume transmission is broadcast to the plurality of wireless electronic tags at each predetermined interval.

[0028] Furthermore, for example, the communication method may further include: an identification step, identifying that the plurality of wireless electronic tags have begun to move toward an area requiring the use of the second frequency, the second frequency being a frequency different from the first frequency currently used by the plurality of wireless electronic tags; and a confirmation step, confirming that the plurality of wireless electronic tags have entered the area. In the signal transmission step, when it is identified in the identification step that the plurality of wireless electronic tags have begun to move toward the area, a signal including an instruction to stop transmission is broadcast to the plurality of wireless electronic tags at each predetermined interval; and when it is confirmed in the confirmation step that the plurality of wireless electronic tags have entered the area, a signal including an instruction to change the first frequency currently used by the plurality of wireless electronic tags to the second frequency is broadcast to the plurality of wireless electronic tags at each predetermined interval.

[0029] Furthermore, in one embodiment of this disclosure, the wireless electronic tag is one of the multiple wireless electronic tags in a communication system consisting of a wireless access point and multiple wireless electronic tags. The wireless electronic tag includes: a carrier sensing unit that performs carrier sensing at each predetermined interval; an output control unit that, during the execution of carrier sensing, if no signal is detected being transmitted to the wireless access point from a wireless electronic tag different from the wireless electronic tag, and if the transmission is not in a stopped state, sends first data to the wireless access point, the first data including ID information for uniquely identifying the wireless electronic tag; an interpretation unit that, during the execution of carrier sensing, detects the signal and, if the signal is not transmitted to the wireless access point from a wireless electronic tag different from the wireless electronic tag, interprets the detected signal as a signal transmitted from the wireless access point and interprets any instructions included in the signal transmitted from the wireless access point; and a frequency control unit that, if the interpretation unit interprets the signal as including an instruction to indicate a frequency change, changes the radio frequency of the signal transmitted by the wireless electronic tag.

[0030] Furthermore, these general or specific forms can be realized by systems, methods, integrated circuits, computer programs, or computer-readable recording media such as CD-ROMs, or by any combination of systems, methods, integrated circuits, computer programs, and recording media.

[0031] The communication method disclosed herein allows for the modification of the frequency of active wireless electronic tags that do not have a unit for receiving data. Attached Figure Description

[0032] Figure 1 An example of the configuration of the communication system involved in the implementation is shown.

[0033] Figure 2 This is a block diagram illustrating the functional configuration of the AP involved in the implementation.

[0034] Figure 3 An example of the hardware configuration of a computer that implements the functions of an AP by software, as described in the implementation method, is shown.

[0035] Figure 4 This conceptually illustrates an example of a signal that includes instructions broadcast by a signal transmitting unit, as per the implementation method.

[0036] Figure 5 This is a block diagram illustrating the functional configuration of the wireless electronic tag according to the embodiment.

[0037] Figure 6 This diagram is used to conceptually illustrate the execution of the first carrier sensing involved in the implementation method.

[0038] Figure 7 This diagram is used to conceptually illustrate the execution of second carrier sensing in the implementation method.

[0039] Figure 8A This diagram is used to illustrate an implementation example of first carrier sensing according to the implementation method.

[0040] Figure 8B This diagram is used to illustrate an implementation example of second carrier sensing according to the implementation method.

[0041] Figure 9 It shows Figure 5 This is an example of a detailed functional block of the control circuit included in the LSI section.

[0042] Figure 10A An example of the first data involved in the implementation is shown.

[0043] Figure 10B An example of the second data involved in the implementation is shown.

[0044] Figure 11A An example of the working sequence of the communication system involved in the comparative example is shown.

[0045] Figure 11B An example of the working sequence of the communication system involved in the implementation is shown.

[0046] Figure 12A This is a diagram used to illustrate the operation of the AP and multiple wireless electronic tags involved in CASE1.

[0047] Figure 12B This is a diagram used to illustrate the operation of the AP and multiple wireless electronic tags involved in CASE1.

[0048] Figure 12C This is a diagram used to illustrate the operation of the AP and multiple wireless electronic tags involved in CASE1.

[0049] Figure 12D This is a diagram used to illustrate the operation of the AP and multiple wireless electronic tags involved in CASE1.

[0050] Figure 12E This is a diagram used to illustrate the operation of the AP and multiple wireless electronic tags involved in CASE1.

[0051] Figure 12F This is a diagram used to illustrate the operation of the AP and multiple wireless electronic tags involved in CASE1.

[0052] Figure 13A This is a diagram used to illustrate the operation of the AP and multiple wireless electronic tags involved in CASE3.

[0053] Figure 13B This is a diagram used to illustrate the operation of the AP and multiple wireless electronic tags involved in CASE3.

[0054] Figure 14 This is a flowchart illustrating the operational overview of the wireless electronic tag involved in the implementation method.

[0055] Figure 15 This is a flowchart illustrating an example of the detailed operation of a wireless electronic tag involved in an implementation.

[0056] Figure 16 This is a flowchart illustrating the working principle of the AP involved in the implementation method.

[0057] Figure 17 This is a flowchart illustrating an example of the detailed operation of the AP involved in the implementation.

[0058] Figure 18 This is a flowchart illustrating an example of the detailed operation of the AP involved in the implementation. Detailed Implementation

[0059] The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. Furthermore, the embodiments described below are all specific examples of this disclosure. The numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection methods, usage order, communication order, etc., shown in the following embodiments are all examples and are not intended to limit this disclosure. Moreover, constituent elements not described in the technical solution illustrating the highest-level concept of this disclosure are described as arbitrary constituent elements. Furthermore, the figures are not strictly illustrative. In the figures, substantially identical components are given the same symbols, and repeated descriptions are omitted or simplified.

[0060] (Implementation Method)

[0061] The following description, with reference to the accompanying drawings, explains the wireless electronic tag and AP (wireless access point) involved in the implementation.

[0062] [1 Communication System]

[0063] Figure 1 An example of the configuration of the communication system 1 according to the embodiment is shown. For example... Figure 1As shown, the communication system 1 includes: multiple wireless electronic tags 10, and an AP 20 capable of changing the frequencies used by the multiple wireless electronic tags 10 under its management. For example, the communication system 1 can be used to identify, manage, or track the location of items assigned with wireless electronic tags 10. The wireless electronic tags 10 will be described in detail later; they are active wireless electronic tags that only have carrier sensing capabilities and no data receiving capabilities. Details about the AP 20 will also be described later; here, the AP 20 can be considered as being able to utilize GPS (Global Positioning System).

[0064] The following is a description of each device.

[0065] [1.2AP20]

[0066] The following describes the configuration of AP20 as described in this embodiment. Figure 2 This is a block diagram illustrating the functional configuration of AP20 according to the embodiment.

[0067] The AP20, implemented by a computer or similar device, is a wireless base station that manages multiple wireless electronic tags 10. Furthermore, the AP20 can function as a terminal in a communication network, connecting wirelessly to the network. While the following explanation describes the AP20's ability to utilize GPS, this is not the sole purpose; the goal is simply to enable the AP20's location to be identified via the communication network.

[0068] In this embodiment, as Figure 2 As shown, AP20 includes: an information collection unit 201, an identification unit 202, a confirmation unit 203, a signal output control unit 204, and a memory 205.

[0069] Before explaining the functional configuration of AP20 in this embodiment, we will first utilize... Figure 3 An example of the hardware configuration of the AP20 involved in this embodiment will be described.

[0070] [1.2.1 Hardware Configuration]

[0071] Figure 3 An example of the hardware configuration of a computer 1000 that implements the functions of the AP20 involved in the implementation method by software is shown.

[0072] like Figure 3As shown, computer 1000 is a computer equipped with input device 1001, output device 1002, CPU 1003, internal storage 1004, RAM 1005, reading device 1007, transceiver device 1008, and bus 1009. Input device 1001, output device 1002, CPU 1003, internal storage 1004, RAM 1005, reading device 1007, and transceiver device 1008 are connected via bus 1009.

[0073] The input device 1001 is a device that serves as a user interface, such as an input key, touchpad, or touchscreen display, and accepts user operations. In addition to accepting user touch operations, the input device 1001 can also be configured to accept operations via voice or remote operation via a remote control.

[0074] The output device 1002 consists of a touchpad or touch screen display that is compatible with the input device 1001, and notifies the user of information that should be given to the user.

[0075] Internal storage 1004 may be flash memory or the like. Furthermore, at least one of the program for implementing the functions of AP20 and the application program that utilizes the functions of AP20 may also be pre-stored in internal storage 1004.

[0076] RAM1005 is Random Access Memory, which is used to store data and other information during the execution of programs or applications.

[0077] The reading device 1007 reads information from a recording medium such as a USB (Universal Serial Bus) memory. The reading device 1007 reads these programs or applications from a recording medium that records them, and stores them in the internal storage 1004.

[0078] The transceiver 1008 is a communication circuit used for communication via wireless or wired means. For example, the transceiver 1008 can communicate with a server device or cloud connected to a network, and can download the aforementioned programs and applications from the server device or cloud and store them in its internal storage 1004.

[0079] CPU 1003 is the Central Processing Unit. It copies programs and application programs stored in internal memory 1004 to RAM 1005, and then reads and executes the instructions contained in these programs or application programs sequentially from RAM 1005. Alternatively, it can execute directly from internal memory 1004.

[0080] Next, the functional configurations of AP20 as described in this embodiment will be explained.

[0081] [1.2.2 Information Collection Department 201]

[0082] The information collection unit 201 collects ID information, which is used to uniquely identify each of the plurality of wireless electronic tags 10. In this embodiment, the information collection unit 201 collects the ID information of all wireless electronic tags managed by the AP 20 via a communication network and stores it in the memory 205. Here, the communication network is, for example, a cellular wireless communication network.

[0083] [1.2.3 Identification Unit 202]

[0084] The identification unit 202 identifies that the multiple wireless electronic tags 10 have begun moving towards an area requiring the use of a second frequency, which is a frequency different from the first frequency currently being used by the multiple wireless electronic tags 10. In this embodiment, the identification unit 202 may also identify that the wireless electronic tags 10 have begun moving based on location information of the multiple wireless electronic tags 10 managed by the AP 20. Furthermore, the identification unit 202 may also obtain departure-related information, such as departure time, obtained from the ID information of the multiple wireless electronic tags 10, via a communication network to identify that the multiple wireless electronic tags 10 have begun moving.

[0085] The identification unit 202 can also identify the movement of multiple wireless electronic tags 10 towards areas requiring the use of a second frequency, which is a frequency different from the first frequency currently used by the multiple wireless electronic tags 10. In this embodiment, the identification unit 202 can, for example, obtain the area information of the mobile destination of the wireless electronic tags 10 via a communication network based on the ID information of the wireless electronic tags 10 managed by the AP 20. Accordingly, the identification unit 202 is able to identify the movement of multiple wireless electronic tags 10 towards areas using frequencies different from the frequencies currently in use.

[0086] [1.2.4 Confirmation Section 203]

[0087] The verification unit 203 verifies (identifies) whether the multiple wireless electronic tags 10 are under the management of the AP 20. Furthermore, the verification unit 203 uses GPS or the like to verify (identify) the area where the AP 20 is located. In this embodiment, the description focuses on the AP 20 and the multiple wireless electronic tags 10 moving together. For this purpose, the verification unit 203 uses GPS to verify the location of the AP 20, and by verifying that the AP 20 has entered the area, it can verify that the multiple wireless electronic tags 10 have entered the area. If the AP 20 identifies its location via a communication network without using GPS, the verification unit 203 performs the same operation, so the description is omitted.

[0088] Furthermore, AP20 is not limited to traveling alongside multiple wireless electronic tags 10; it may also choose not to travel alongside multiple wireless electronic tags 10. In this case, the wireless electronic tags 10 can be managed separately by AP20s located in the area before and at the destination of the multiple wireless electronic tags 10.

[0089] [1.2.5 Signal Output Control Unit 204]

[0090] The signal output control unit 204 controls the output of a signal (a radio wave of a specific frequency). For example... Figure 2 As shown, the signal output control unit 204 includes a signal transmitting unit 2041 and a signal stopping unit 2042.

[0091] [1.2.5.1 Signal Transmission Unit 2041]

[0092] The signal transmitting unit 2041 broadcasts signals to the plurality of wireless electronic tags 10 at each specified period, including instructions to change the first frequency currently used by the plurality of wireless electronic tags 10 to a second frequency.

[0093] For example, suppose the identification unit 202 detects that multiple wireless electronic tags 10 have begun to move toward the area. In this case, the signal transmitting unit 2041, at each predetermined interval, issues an instruction to the multiple wireless electronic tags 10 to change the first frequency currently used by the multiple wireless electronic tags 10 to a second frequency, and broadcasts a signal including an instruction to stop transmitting.

[0094] Therefore, when the confirmation unit 203 confirms that multiple wireless electronic tags 10 have entered the area, the signal transmitting unit 2041 broadcasts signals including instructions to start transmission to the multiple wireless electronic tags 10 at each predetermined interval.

[0095] In this way, the signal transmitting unit 2041 can change the frequency (radio frequency) used by the multiple wireless electronic tags 10 at the moment when the multiple wireless electronic tags 10 begin to move (depart) to the area, and can stop the transmission.

[0096] Furthermore, if the identification unit 202 detects that multiple wireless electronic tags 10 have begun moving into the area, the signal transmitting unit 2041 may not broadcast a signal to the multiple wireless electronic tags 10 including an instruction to change the currently used first frequency to the second frequency. In other words, the signal transmitting unit 2041 may broadcast a signal to the multiple wireless electronic tags 10 at predetermined intervals, including an instruction to stop transmitting. Therefore, if the confirmation unit 203 confirms that multiple wireless electronic tags 10 have entered the area, the signal transmitting unit 2041 may broadcast a signal to the multiple wireless electronic tags 10 at predetermined intervals, including an instruction to change the currently used first frequency to the second frequency.

[0097] In this way, the signal transmitting unit 2041 can stop transmitting signals to the multiple wireless electronic tags 10 only when the multiple wireless electronic tags 10 begin to move (depart) to the area, and change the frequency (wireless frequency) currently in use after the multiple wireless electronic tags 10 have entered the area.

[0098] Figure 4 Conceptually, an example of a signal including instructions broadcast by the signal transmitting unit 2041 according to the embodiment is shown. The signal including the instructions is broadcast via the antenna of AP20.

[0099] For example Figure 4 As shown, instructions to indicate frequency changes, instructions to stop transmission, or instructions to resume transmission can be broadcast in the signal by using an on-off-keying (OOK) control that periodically changes the signal strength.

[0100] However, the method of including these instructions in the signal is not subject to Figure 4 The example shown is limited. Alternatively, a signal can be generated by on / off keying, in a manner that corresponds to a specific instruction, causing the signal strength to change to below a threshold value at regular intervals and a predetermined number of times.

[0101] [1.2.5.2 Signal stop part 2042]

[0102] The signal stopping unit 2042 stops broadcasting signals including instructions after confirming that information indicating that an instruction has been received has been received from each of the plurality of wireless electronic tags 10.

[0103] [1.2.6 Memory 205]

[0104] Memory 205 is an example of a storage medium, such as a rewritable, non-volatile memory like a hard disk drive or solid-state drive. Storage media equivalent to memory 205 can also exist in the cloud.

[0105] [1.3 Wireless Electronic Tag 10]

[0106] Next, the configuration of the wireless electronic tag 10 involved in this embodiment will be described. Figure 5 This is a block diagram illustrating the functional configuration of the wireless electronic tag 10 according to the embodiment.

[0107] The wireless electronic tag 10 is an active wireless electronic tag that is powered by an internal battery and emits its own radio waves. It does not have data reception capabilities but only carrier sensing capabilities. The wireless electronic tag 10 is assigned (attached) or distributed to items such as goods. In this embodiment, the wireless electronic tag 10 can use the carrier sensing function to receive signals indicating frequency (radio frequency) changes, etc. (to interpret instructions). Figure 5 As shown, the wireless electronic tag 10 includes: a battery 11, a sensor 12 for sensing the state of an item, and an LSI (Large Scale Integration) unit 13.

[0108] Battery 11 is embedded in wireless electronic tag 10 and provides power to LSI unit 13.

[0109] Sensor 12 senses the state of an item that has been fitted with or given a wireless electronic tag 10, and transmits the sensing results to LSI unit 13. However, sensor 12 is not strictly necessary.

[0110] LSI section 13 will be discussed later.

[0111] [1.3.1LSI Section 13]

[0112] The LSI unit 13 is composed of an IC chip powered by the battery 11. The LSI unit 13 is connected to an antenna and can transmit radio waves (signals) to the AP20 when no other wireless electronic tags 10 (hereinafter referred to as other wireless electronic tags 10) are emitting radio waves (signals). The LSI unit 13 is implemented by a CPU, a memory 134, etc.

[0113] In this embodiment, the LSI unit 13 includes: an RF (Radio Frequency) unit 130, a radio wave intensity measurement unit 131, a carrier sensing unit 132, a control circuit 133, a memory 134, and a data modulation unit 135.

[0114] [1.3.1.1 RF Section 130]

[0115] The RF unit 130 includes TX1301 and RX1302, which transmit and receive signals (radio waves) via an antenna. TX1301 is a transmitting circuit that converts the signal modulated by the data modulation unit 135 into radio waves in the frequency band used by the wireless electronic tag 10, and transmits the signal as radio waves via the antenna. RX1302 is a receiving circuit that converts the radio waves in the frequency band used by the wireless electronic tag 10 received by the antenna into a signal (received signal), and transmits it to the radio wave intensity measurement unit 131.

[0116] [1.3.1.2 Radio Wave Intensity Measurement Unit 131]

[0117] The radio wave strength measurement unit 131 calculates the strength of the signal received during carrier sensing. In this embodiment, the radio wave strength measurement unit 131 measures the strength of the radio waves received by the RF unit 130 by calculating the strength of the received signal in the frequency band used by the wireless electronic tag 10 transmitted by the RF unit 130 during carrier sensing. Furthermore, the radio wave strength measurement unit 131 calculates the received signal strength using RSSI (Received Signal Strength Indication).

[0118] [1.3.1.3 Carrier Sensing Unit 132]

[0119] The carrier sensing unit 132 performs carrier sensing at predetermined intervals. More specifically, the carrier sensing unit 132 monitors the radio wave strength measured by the radio wave strength measurement unit 131 during carrier sensing to confirm whether the frequency band used by itself (the wireless electronic tag 10) is occupied by radio waves emitted by other wireless electronic tags, etc. The carrier sensing unit 132 transmits the confirmation result to the control circuit 133.

[0120] In this embodiment, the carrier sensing unit 132 monitors the strength of the received signal calculated by the radio wave strength measurement unit 131 during carrier sensing to detect whether other wireless electronic tags 10 are transmitting signals and whether the AP 20 is transmitting signals. Hereinafter, the general carrier sensing used to detect whether other wireless electronic tags 10 are transmitting radio waves will be referred to as first carrier sensing, and the pattern recognition carrier sensing used to detect whether the AP 20 is transmitting signals will be referred to as second carrier sensing. The carrier sensing unit 132 may perform first carrier sensing and second carrier sensing simultaneously during each predetermined period of carrier sensing, or it may alternate between performing first carrier sensing and second carrier sensing during each predetermined period. An example of the case where first carrier sensing and second carrier sensing are performed alternately will be described below.

[0121] Figure 6 This diagram illustrates the conceptual implementation of first carrier sensing in the proposed method. (As shown...) Figure 6 As shown in (a), in the case where other wireless electronic tags 10 are transmitting radio waves, Figure 6 The electromagnetic wave intensity shown in (b) is measured by the electromagnetic wave intensity measuring unit 131. Therefore, as... Figure 6 As shown in (b), the carrier sensing unit 132 detects a busy state in which other wireless electronic tags 10 are transmitting signals during the period when the measured radio wave intensity exceeds the first threshold.

[0122] In addition, Figure 6 During the period shown in (b) when the radio wave intensity is not measured, that is, during the period when the radio wave intensity measured by the radio wave intensity measuring unit 131 is below the threshold, the carrier sensing unit 132 detects that it is an idle state where no other wireless electronic tag 10 is transmitting a signal. Therefore, in the idle state, radio waves can be transmitted by the control circuit 133 described later in the frequency band used by the wireless electronic tag 10. In other words, by performing the first carrier sensing, the wireless electronic tag 10 is able to avoid radio wave collisions with other wireless electronic tags 10 to transmit radio waves.

[0123] Figure 7 This diagram illustrates the conceptual implementation of second carrier sensing in the proposed method. (As shown...) Figure 7 As shown in (a), when AP20 broadcasts a signal including instructions, the radio wave intensity measurement unit 131 measures the radio wave intensity (not shown). Therefore, when the carrier sensing unit 132 detects a period in which the radio wave intensity measured by the radio wave intensity measurement unit 131 exceeds a second threshold, as... Figure 7 As shown in (b), the repetitive pattern (received intensity pattern) in the radio wave intensity is detected. Additionally, as... Figure 7 As shown in (b), the repetition pattern can be defined by the number of periods in each certain cycle, and the number of periods is the number of periods where the radio wave intensity measured by the radio wave intensity measuring unit 131 is below a second threshold. The second threshold may be different from or the same as the first threshold.

[0124] Next, using Figure 8A A specific example of the execution of carrier sensing is explained.

[0125] Figure 8A This is a diagram used to illustrate an implementation example of first carrier sensing according to the implementation method.

[0126] In the execution of carrier sensing, for example Figure 8AThe received signal shown in (a) is transmitted from RX1302 to the radio wave intensity measurement unit 131, and the radio wave intensity measurement unit 131... Figure 8A The strength of the received signal (signal strength) shown in (b) is calculated. Therefore, the carrier sensing unit 132... Figure 8A As shown in (c), the calculated strength of the received signal is divided into the first period and averaged. Periods in which the averaged first strength exceeds the first threshold are judged as busy states, and periods in which the strength does not exceed the first threshold are judged as idle states. Then, the carrier sensing unit 132 transmits the judgment result as the first carrier sensing result to the control circuit 133.

[0127] Next, using Figure 8B A specific example of the execution of second carrier sensing is explained.

[0128] Figure 8B This is a diagram illustrating an implementation example of second carrier sensing as described in the embodiment.

[0129] In the execution of carrier sensing, for example Figure 8B The received signal shown in (a) is transmitted from RX1302 to the radio wave intensity measurement unit 131, and the radio wave intensity measurement unit 131... Figure 8B The strength of the received signal (signal strength) shown in (b) is calculated. Therefore, the carrier sensing unit 132... Figure 8B As shown in (c), the calculated received signal strength is divided into two periods, each shorter than the first period, and averaged. A pattern (received strength pattern) consisting of the number of averaged second-averaged strengths exceeding a second threshold and the number falling below the second threshold is determined. The carrier sensing unit 132 then transmits the determination result as a second carrier sensing result to the control circuit 133.

[0130] [1.3.1.4 Control Circuit 133]

[0131] When the control circuit 133 receives the first carrier sensing result from the carrier sensing unit 132, it transmits its own (wireless electronic tag 10) ID information stored in the memory 134 to the data modulation unit 135. Furthermore, when the control circuit 133 receives the second carrier sensing result from the carrier sensing unit 132, it stores the pattern (received strength pattern) included in the second carrier sensing result into a portion of the memory 134 (pattern buffer 134a). If the control circuit 133 interprets the instruction using the transmitted second carrier sensing result, it adds information indicating that an ACK message (Acknowledgement message) or similar instruction has been received to its own (wireless electronic tag 10) ID information stored in the memory 134 and transmits this information to the data modulation unit 135. The control circuit 133 then performs operations corresponding to the interpreted instruction.

[0132] Figure 9 It shows Figure 5 An example of the detailed functional blocks of the control circuit 133 included in the LSI section 13 shown.

[0133] like Figure 9 As shown, the control circuit 133 includes a pattern matching determination unit 1331, an interpretation unit 1332, an RF frequency control unit 1333, and an RF output control unit 1334. Furthermore, the control circuit 133 executes the functions of the pattern matching determination unit 1331, the interpretation unit 1332, the RF frequency control unit 1333, and the RF output control unit 1334 using a control program stored in the memory 134. Moreover, the pattern matching determination unit 1331, the interpretation unit 1332, the RF frequency control unit 1333, and the RF output control unit 1334 can also be executed by hardware.

[0134] [1.3.1.4.1 Style Matching Decision Unit 1331]

[0135] The pattern matching determination unit 1331 performs a matching determination on the recurring patterns (received strength patterns) included in the second carrier listening results transmitted from the carrier listening unit 132 and stored in a portion of the memory 134, namely the pattern buffer 134a. More specifically, the pattern matching determination unit 1331 determines whether the recurring patterns (received strength patterns) included in the second carrier listening results match one of a plurality of pre-set patterns.

[0136] [1.3.1.4.2 Explanation Section 1332]

[0137] During carrier sensing, the interpretation unit 1332 detects the signal and, if the signal is not a signal sent to AP20 by other wireless electronic tags, interprets the detected signal as a signal sent from AP20 and includes the instructions contained in the signal sent from AP20. More specifically, the interpretation unit 1332 interprets the instructions contained in the signal sent from AP20 by combining the number of times the second averaging intensity of the repeating pattern included in the second carrier sensing result exceeds a second threshold with the number of times it falls below the second threshold. For example, the interpretation unit 1332 may interpret the instructions contained in the signal as instructions to stop transmission and change frequency, or as instructions to resume transmission. Furthermore, the interpretation unit 1332 may interpret the instructions contained in the signal as instructions to stop transmission or instructions to change frequency.

[0138] In this embodiment, if the repeating pattern (received strength pattern) included in the second carrier sensing result matches one of a plurality of preset patterns, the interpretation unit 1332 interprets the instruction corresponding to the matching pattern as an instruction included in the signal sent from AP20.

[0139] [1.3.1.4.3 RF Frequency Control Unit 1333]

[0140] When the RF frequency control unit 1333 is interpreted by the interpretation unit 1332 as including the instruction for indicating frequency change in the signal transmitted from the AP20, it changes the radio frequency of the signal transmitted by itself (the wireless electronic tag 10).

[0141] In addition, when the interpretation unit 1332 interprets the instruction for indicating transmission stop and frequency change as being included in the signal sent from AP20, the RF frequency control unit 1333 changes the radio frequency of the signal it transmits after the second data with ACK added to the ID information is sent.

[0142] Additionally, ACK, as described above, is an example of a message indicating that an instruction has been received.

[0143] [1.3.1.4.4 RF Output Control Unit 1334]

[0144] The RF output control unit 1334 can control the output of signals sent to AP20, as well as control the stopping or restarting of signal transmission to AP20 (start transmission).

[0145] For example, if the RF output control unit 1334 does not detect any signals sent to the AP20 by other wireless electronic tags 10 during carrier sensing, and without being instructed to stop transmitting, it sends the first data, including its own (wireless electronic tag 10) ID information, to the AP20.

[0146] Figure 10A An example of the first data involved in the implementation is shown. For example... Figure 10A As shown, the first data involved in this embodiment is the ID information of the wireless electronic tag 10 included in the data field.

[0147] Furthermore, for example, if the RF output control unit 1334 interprets the instruction to stop transmission and change frequency as included in the signal transmitted from AP20, and no other signals transmitted to AP20 by wireless electronic tags 10 are detected during carrier sensing, then the RF output control unit 1334 may send the second data, obtained by adding an ACK message to the first data, to AP20. In this case, after the second data is transmitted, the RF output control unit 1334 stops transmitting signals to AP20 until the interpretation unit 1332 interprets the instruction to resume transmission as included in the signal transmitted from AP20 detected during carrier sensing. Thus, when the radio frequency of the signal transmitted by the RF frequency control unit 1333 itself (wireless electronic tag 10) is changed, the RF output control unit 1334 can resume transmitting signals to AP20.

[0148] Figure 10B An example of the second data involved in the implementation is shown. For example... Figure 10B As shown, the second data involved in this embodiment is the data after adding an ACK message to the ID information (first data) of the wireless electronic tag 10 included in the data field. The ACK message can be added to an empty area of ​​the data field.

[0149] Alternatively, for example, if the RF output control unit 1334 interprets the instruction to stop transmission as being included in the signal transmitted from AP20 by the interpretation unit 1332, and no other signals transmitted to AP20 by the wireless electronic tag 10 are detected during carrier sensing, then the second data, which is data with an ACK message added to the first data, can be transmitted to AP20. In this case, the RF output control unit 1334 stops transmitting signals to AP20 after the second data is transmitted.

[0150] [1.3.1.5 Memory 134]

[0151] Memory 134 is an example of a storage medium such as flash memory. Memory 134 is not subject to settings. Figure 5 Due to limitations in the control circuit 133 shown, it can also be located outside the control circuit 133 and inside or outside the LSI section 13.

[0152] In this embodiment, the memory 134 stores control programs for the LSI unit 13 to operate the radio wave intensity measurement unit 131, the carrier sensing unit 132, and the data modulation unit 135. Furthermore, the memory 134 stores control programs for the control circuit 133 to operate the pattern matching determination unit 1331, the interpretation unit 1332, the RF frequency control unit 1333, and the RF output control unit 1334. Additionally, a portion of the memory 134 is also used as a buffer (pattern buffer 134a) by the control circuit 133.

[0153] [1.3.1.6 Data Modulation Unit 135]

[0154] The data modulation unit 135 performs modulation for transmitting data onto radio waves. More specifically, the data modulation unit 135 performs modulation for transmitting radio waves onto its own wireless electronic tag 10's ID information transmitted from the control circuit 133.

[0155] [2. Operation of Communication System 1, etc.]

[0156] Next, the operation of the communication system 1, which consists of multiple wireless electronic tags 10 and AP 20 as described above, will be explained.

[0157] [2.1 Working Sequence of Communication System 1]

[0158] First, before describing the working sequence of the communication system 1 according to this embodiment, as a comparative example, the working sequence of the communication system according to the comparative example having wireless electronic tags 90A and 90B that are generally only capable of carrier sensing (first carrier sensing) will be described.

[0159] Figure 11A An example of the working sequence of the communication system involved in the comparative example is shown.

[0160] like Figure 11AAs shown, in the communication system involved in the comparative example, wireless electronic tag 90A and wireless electronic tag 90B each perform carrier sensing (carrier sensing) according to each predetermined period. More specifically, wireless electronic tag 90A performs normal carrier sensing (corresponding to the first carrier sensing) according to each predetermined period. If it detects that other wireless electronic tags 90B are in an idle state and not transmitting radio waves, it sends the ID information of wireless electronic tag 90A (corresponding to the first data) to AP91. Similarly, wireless electronic tag 90B performs normal carrier sensing (corresponding to the first carrier sensing) according to each predetermined period. If it detects that other wireless electronic tags 90A are in an idle state and not transmitting radio waves, it sends the ID information of wireless electronic tag 90B (corresponding to the first data) to AP91.

[0161] Figure 11B An example of the working sequence of the communication system 1 involved in the implementation is shown.

[0162] like Figure 11B As shown, in the communication system 1 according to this embodiment, wireless electronic tags 10A and 10B perform normal carrier sensing and pattern identification carrier sensing respectively according to each predetermined period. More specifically, wireless electronic tags 10A and 10B alternately perform first carrier sensing (normal carrier sensing) and second carrier sensing (pattern identification carrier sensing) according to each predetermined period. Here, it is regarded that AP20 broadcasts signals including instructions to stop transmission and change frequency for a certain period of time according to each predetermined period.

[0163] When wireless electronic tag 10A performs first carrier sensing and detects that it is in an idle state where other wireless electronic tags 10B are not transmitting radio waves, it sends the ID information (first data) of wireless electronic tag 10A to AP20. Similarly, when wireless electronic tag 10B performs first carrier sensing and detects that it is in an idle state where other wireless electronic tags 10A are not transmitting radio waves, it sends the ID information (first data) of wireless electronic tag 10B to AP20.

[0164] Furthermore, when the wireless electronic tag 10A performs second carrier sensing and detects a recurring pattern (received strength pattern) in the received signal, it interprets the instructions included in the signal from the detected recurring pattern (received strength pattern). Upon interpreting the instructions included in the signal, the wireless electronic tag 10A, during the next transmission timing (i.e., performing first carrier sensing and detecting an idle state), sends second data to the AP20. This second data is obtained by adding an ACK message to the ID information of the wireless electronic tag 10A.

[0165] Similarly, when the wireless electronic tag 10B performs second carrier sensing and detects a recurring pattern (received strength pattern) in the received signal, it interprets the instructions included in the signal from the detected recurring pattern. Upon interpreting the instructions included in the signal, the wireless electronic tag 10B, during the next timing period (i.e., performing first carrier sensing and detecting an idle state), sends second data to the AP20. This second data is obtained by adding an ACK message to the ID information of the wireless electronic tag 10B.

[0166] [2.2 Application Scenarios of Communication System 1]

[0167] Next, the application scenario of communication system 1 in logistics will be described. The application scenario where AP20 moves alongside multiple wireless electronic tags 10 under its management, i.e., moves alongside wireless electronic tags 10 attached to goods, is referred to as CASE 1. Figures 12A to 12F To illustrate.

[0168] <case1>

[0169] Figures 12A-12B This is a diagram used to illustrate the operation of AP20 and multiple wireless electronic tags 10 involved in CASE1.

[0170] Figure 12A An example of the operation of the communication system 1 according to the embodiment for the logistics scene in region A, including the AP20 and multiple wireless electronic tags 10, is shown.

[0171] like Figure 12A As shown, each of the plurality of wireless electronic tags 10 alternately performs listening to the first carrier and the second carrier, transmitting first data including ID information at regular intervals (each specified period). Here, since each of the plurality of wireless electronic tags 10 is used for logistics within region A, it transmits a signal on a radio frequency (the first frequency) used in region A.

[0172] In addition, AP20 collects and stores ID information of multiple wireless electronic tags 10 under its management. Furthermore, AP20 is connected to the wireless communication network of the cellular network in region A. Although AP20 stores ID information, in cases where this ID information would be lost when power is cut off, the stored ID information can be loaded onto a specific server or the cloud.

[0173] Figure 12B as well as Figure 12C The illustration shows an example of the operation of an AP20 and multiple wireless electronic tags 10 in a scenario where the communication system 1 according to the embodiment starts from region A and travels to other regions B.

[0174] exist Figure 12B In this process, AP20 obtains departure-related information from the ID information of multiple wireless electronic tags 10 through the location information or wireless communication network managed by the multiple wireless electronic tags 10, and identifies that the multiple wireless electronic tags 10 have begun to move. Here, AP20, for example, accesses a specific server or cloud via a wireless communication network to obtain the region information (region B) that is the mobile destination of the wireless electronic tags 10 from the ID information of the managed wireless electronic tags 10. Thus, as... Figure 12B As shown, AP20 issues instructions to multiple wireless electronic tags 10 to change the first frequency to the second frequency, and broadcasts signals including instructions to stop transmission.

[0175] Furthermore, each of the plurality of wireless electronic tags 10 alternates between listening to the first carrier and listening to the second carrier, transmitting first data including ID information at regular intervals (each predetermined period). The plurality of wireless electronic tags 10 perform second carrier listening, interpreting the instructions included in the signal and operating according to the interpreted instructions. For example... Figure 12B As shown, the multiple wireless electronic tags 10, following the explained instructions, send an ACK at the next transmission time and stop transmitting signals thereafter. Furthermore, after sending the ACK, the multiple wireless electronic tags 10, following the explained instructions, change the used radio frequency from frequency 1 to frequency 2.

[0176] Therefore, in Figure 12C In the example shown, the radio frequencies of all multiple wireless electronic tags 10 are changed from frequency 1 to frequency 2, and the state where signal transmission is stopped and broadcasting stops because AP 20 has received ACKs from multiple wireless electronic tags 10 are also shown. Furthermore, even if AP 20 fails to receive ACKs from multiple wireless electronic tags 10, broadcasting can also be stopped if, after a certain period has elapsed since the last ACK received from any of the multiple wireless electronic tags 10, no signals from other wireless electronic tags 10 are received.

[0177] Figure 12D An example of the operation of the communication system 1 according to the embodiment entering the scene of region B, including the AP20 and multiple wireless electronic tags 10, is shown.

[0178] like Figure 12D As shown, each of the multiple wireless electronic tags 10 alternates between first carrier listening and second carrier listening on the radio frequency (second frequency) used in area B. Furthermore, when the AP 20 confirms that it has entered area B using GPS or the like, it broadcasts a signal including instructions to begin transmission to the multiple wireless electronic tags 10 on the second frequency. Additionally, if the AP 20 loses the ID information stored at the time of departure due to power loss after leaving area A, it can retrieve the ID information by accessing a specific server or the cloud.

[0179] Figure 12E as well as Figure 12F The following is an example of the operation of the communication system 1 involved in the embodiment in region B, up to the point that all of the multiple wireless electronic tags 10 under the management of AP20 have started transmitting.

[0180] exist Figure 12E The example shows how each of the multiple wireless electronic tags 10 performs second carrier sensing and, according to the interpreted instructions, begins (or restarts) transmitting the signal of the first data. It also shows how broadcasting continues until AP20 has received the first data from all the multiple wireless electronic tags 10. Furthermore, in... Figure 12F The example shown illustrates how the broadcasting stopped because AP20 received the first data from multiple wireless electronic tags 10.

[0181] <case2>

[0182] While CASE 1 states that upon departure, AP 20 identifies the destination of the multiple wireless electronic tags 10 under its management as region B, this is not a limitation. AP 20 may also fail to identify the destination of the multiple wireless electronic tags 10 under its management as region B. The following explanation of the inability to identify the destination as region B is presented as CASE 2. In other words, CASE 2 describes a scenario where AP 20 is traveling alongside multiple wireless electronic tags 10 under its management, but cannot identify their destination as region B. See below for further details. Figures 12A to 12F The following explanation will focus on the differences. For work identical to CASE1, the explanation will be omitted; only the differences will be explained below.

[0183] In CASE2 Figure 12B In this scenario, AP20 obtains departure-related information from the ID information of multiple wireless electronic tags 10 through the location information or wireless communication network under its management, thereby identifying that the multiple wireless electronic tags 10 have begun to move. However, in CASE2, AP20 cannot obtain the area information (area B) that is the destination of the wireless electronic tags 10. Therefore, AP20 broadcasts a signal to the multiple wireless electronic tags 10 including an instruction to stop transmitting. Thus, in CASE2, AP20 does not broadcast a signal including an instruction to change the first frequency to the second frequency.

[0184] Furthermore, each of the multiple wireless electronic tags 10 alternates between listening to the first carrier and listening to the second carrier, transmitting first data including ID information at regular intervals. In CASE2... Figure 12B In this process, multiple wireless electronic tags 10, following the interpreted instructions, send an ACK at the next transmission time and stop transmitting signals thereafter.

[0185] In CASE2 Figure 12D In this scenario, each of the multiple wireless electronic tags 10 not only performs carrier sensing at the first frequency, but can also alternately perform carrier sensing at the first and second carrier frequencies used in other areas such as B. Furthermore, when AP 20 confirms that it has entered area B using GPS or the like, it broadcasts a signal to the multiple wireless electronic tags 10 at the second frequency, including an instruction to change the first frequency to the second frequency. Thus, in CASE 2, AP 20 does not broadcast a signal including an instruction to begin transmission.

[0186] In CASE2 Figure 12E In this scenario, each of the multiple wireless electronic tags 10 performs second carrier sensing and, according to the interpreted instructions, changes its radio frequency from the first frequency to the second frequency, and begins (restarts) the transmission of the first data signal at the second frequency. However, AP 20 continues broadcasting until the first data has been obtained from all the multiple wireless electronic tags 10. Since this is the same as in CASE 1, further explanation is omitted.

[0187] <case3>

[0188] While CASE 1 and CASE 2 describe the movement of AP 20 alongside multiple wireless electronic tags 10 under its management, this is not a limitation. AP 20 managing multiple wireless electronic tags 10 can also be changed according to region. The following scenario, referred to as CASE 3, involves a scenario where AP 20 does not move alongside multiple wireless electronic tags 10 under its management, the destination of the multiple wireless electronic tags 10 cannot be identified as region B, and AP 20 in the region of origin is used. CASE 3 will be described below.

[0189] Figure 13A as well as Figure 13B This diagram illustrates the operation of AP20 and the multiple wireless electronic tags 10 involved in CASE3. Figure 13A The diagram illustrates an example of the operation of the communication system 1 according to the embodiment, used for the AP20 and multiple wireless electronic tags 10 in a logistics scene within region A. Furthermore, due to... Figure 13A The working example shown is Figure 12A The explanation is the same as that in the previous section, so the explanation is omitted.

[0190] exist Figure 13B The diagram illustrates an example of the operation of the communication system 1 according to the embodiment, which prepares an AP20 and multiple wireless electronic tags 10 in a scene originating from region A.

[0191] exist Figure 13B In this case, AP20, upon receiving indication that multiple wireless electronic tags 10 have originated from region A, broadcasts a signal including an instruction to stop transmission. Thus, in CASE3, AP20 does not broadcast a signal including an instruction to change the first frequency to the second frequency. Furthermore, each of the multiple wireless electronic tags 10 alternates between listening to the first carrier and listening to the second carrier, transmitting first data including ID information at regular intervals. Figure 13B In this process, multiple wireless electronic tags 10, following the interpreted instructions, send an ACK at the next transmission timer and stop subsequent signal transmission. The following is due to the fact that, except for CASE2... Figure 12D The same work is performed outside of this scene, therefore the explanation is omitted.

[0192] Additionally, in CASE3 Figure 12D In this scenario, each of the multiple wireless electronic tags 10 not only performs carrier sensing at the first frequency, but also alternates between carrier sensing and carrier sensing at other radio frequencies used in other areas. Furthermore, when the AP 20 in area B receives a signal indicating that the multiple wireless electronic tags 10 have entered area B, it accesses a specific server or cloud to obtain their ID information. Then, the AP 20 in area B broadcasts a signal at the second frequency for the multiple wireless electronic tags 10, including an instruction to change the first frequency to the second frequency. Thus, the AP 20 in area B in CASE 3 does not broadcast a signal including an instruction to begin transmission.

[0193] [2.3 Operation of Wireless Electronic Tag 10]

[0194] Next, the operation of the wireless electronic tag 10 according to this embodiment will be described.

[0195] Figure 14 This is a flowchart illustrating the operational overview of the wireless electronic tag 10 involved in the implementation.

[0196] First, the wireless electronic tag 10 performs carrier sensing (S10) at each specified period.

[0197] Next, when wireless electronic tag 10 does not detect any other wireless electronic tag 10 signaling to AP20 during carrier sensing and is not in a transmission stop state, it sends the first data including its own (wireless electronic tag 10) ID information to AP20 (S11).

[0198] Next, when the wireless electronic tag 10 detects a signal during carrier sensing and the signal is not a signal sent to the AP20 by other wireless electronic tags 10, the detected signal is treated as a signal sent from the AP20, and the instructions included in the signal sent from the AP20 are interpreted (S12).

[0199] Next, when the wireless electronic tag 10 interprets the signal as containing an instruction to indicate a frequency change, it changes the radio frequency of the signal transmitted by itself (the wireless electronic tag 10) (S13).

[0200] Figure 15 This is a flowchart illustrating an example of the detailed operation of the wireless electronic tag 10 involved in the embodiment.

[0201] First, the wireless electronic tag 10 periodically (at each specified interval) performs carrier sensing (S101). For example, although the wireless electronic tag 10 periodically alternates between performing carrier sensing on the first carrier and carrier sensing on the second carrier, it may also perform carrier sensing on the first carrier and carrier sensing on the second carrier simultaneously.

[0202] Next, during carrier sensing, the wireless electronic tag 10 confirms whether no other wireless electronic tag 10 signals are detected and whether no transmission stop indication is received (S102).

[0203] In step S102, if a signal from another wireless electronic tag 10 is detected, or a stop signal is received (No in step S102), the wireless electronic tag 10 confirms whether the detected signal has been correctly received (S103).

[0204] In step S103, if the wireless electronic tag 10 detects that the signal can be correctly received (No in step S103), it checks whether signals from other wireless electronic tags 10 have been detected (S104). Furthermore, a wireless electronic tag 10 failing to correctly receive a detected signal (Yes in step S103) occurs when it overlaps with signals from other wireless electronic tags 10, or when other wireless electronic tags 10 overlap with signals from AP20.

[0205] In step S104, if no signal from another wireless electronic tag 10 is detected by the wireless electronic tag 10 ("No" in step S104), and a signal from AP 20 is detected ("Yes" in S105), the instruction included in the signal from AP 20 is interpreted (S106). If the wireless electronic tag 10 interprets the signal from AP 20 as an instruction, it can change a state such as an instruction reception state (ACK) held in its internal memory (memory 134) to indicate that an instruction from the AP has been received. Instructions included in the signal from AP 20 may include, for example, instructions to stop (disallow transmission) signal transmission from itself (wireless electronic tag 10), instructions to change the radio frequency used by itself (wireless electronic tag 10) to a specific radio frequency, etc.

[0206] Alternatively, step S105 can be skipped. If step S103 is "yes", step S104 is "yes", and step S105 is "no", return to step S101.

[0207] In step S102, if no other wireless electronic tag 10 signal is detected and no stop signal is received ("Yes" in step S102), the wireless electronic tag 10 confirms whether the instruction was interpreted during the execution of the last carrier listening (second carrier listening) (S107).

[0208] In step S107, if no instruction was interpreted during the previous second carrier listening (No in step S107), the wireless electronic tag 10 sends the ID information to AP20 (S108).

[0209] In step S107, if the instruction was interpreted during the previous second carrier listening ("Yes" in step S107), the wireless electronic tag 10 adds the ACK to the ID information and sends it to AP20 (S109).

[0210] Next, the wireless electronic tag 10 performs the operation corresponding to the instructions interpreted in the previous second carrier sniffing (S110). After execution, the wireless electronic tag 10 returns to step S101.

[0211] In step S110, if the wireless electronic tag 10 sends an ACK to AP20 after receiving an instruction in the signal from AP20 that indicates to stop (disallow transmission) signal transmission from itself (wireless electronic tag 10), it stops subsequent signal transmission. Thus, the wireless electronic tag 10 only needs to change the state (e.g., transmit permission status (TxStop)) held in its internal memory (memory 134) to a state indicating that signal transmission from itself (wireless electronic tag 10) has stopped.

[0212] Furthermore, in step S110, for example, if the signal from AP20 includes an instruction to change the radio frequency used by itself (wireless electronic tag 10) to a specific radio frequency, then after sending an ACK to AP20, wireless electronic tag 10 will change the radio frequency it uses to the specific radio frequency. Thus, wireless electronic tag 10 only needs to change the frequency selection state (Freq) held in its internal memory (memory 134) to indicate that a specific radio frequency has been selected.

[0213] [2.4AP20 Operation]

[0214] Next, the operation of AP20 as described in this embodiment will be explained.

[0215] Figure 16 This is a flowchart illustrating the working principle of AP20 according to the implementation method.

[0216] First, AP20 collects the ID information of each of the multiple wireless electronic tags 10 (S20). More specifically, AP20 collects information as ID information for each of the multiple wireless electronic tags 10 under management, which is used to uniquely identify them.

[0217] Next, AP20 broadcasts, at each specified interval, a signal including an instruction to change the first frequency currently used by the multiple wireless electronic tags 10 to a second frequency (S21).

[0218] Next, AP20 stops broadcasting the signal including the instruction after confirming that the instruction has been received from each of the plurality of wireless electronic tags 10 (S22).

[0219] Figure 17 as well as Figure 18 This is a flowchart illustrating an example of the detailed operation of AP20 as described in the implementation. Figure 17 as well as Figure 18 It should be noted that AP20 and the multiple wireless electronic tags 10 under its management are used for logistics, and the wireless electronic tags 10 can use radio frequencies to move from different regions A to region B. Figure 17 The operation of AP20 in region A is shown. Figure 18 The operation of AP20 in region B is shown.

[0220] Firstly, as Figure 17 As shown, AP20 uses GPS and other methods to identify (confirm) the location in region A (S201).

[0221] Next, AP20 collects the ID information of all wireless electronic tags 10 under its management (S202). For example, AP20 collects and stores the ID information of multiple wireless electronic tags 10 under its management by connecting to the wireless communication network of the cellular network of region A.

[0222] Next, while located in region A, AP20 identifies movement to region B that uses a different frequency (wireless frequency) when transmitting signals to wireless electronic tag 10 (S203). For example, AP20 accesses a specific server or cloud via a wireless communication network and identifies movement of the managed wireless electronic tag 10 to region B by obtaining the region B that is the destination of the wireless electronic tag 10 from the ID information of the managed wireless electronic tag 10.

[0223] Next, AP20 transmits a signal including instructions for frequency change and transmission stop to the managed wireless electronic tags 10 (S204). In this embodiment, AP20 issues an instruction to change the first frequency to the second frequency to a plurality of wireless electronic tags 10, and broadcasts a signal including instructions for transmission stop, transmitting the signal including these instructions to the managed wireless electronic tags 10. Alternatively, AP20 may also transmit a signal including instructions for transmission stop but excluding instructions for frequency change.

[0224] Next, AP20 stops sending instructions to the managed wireless electronic tags after confirming that all instructions from the wireless electronic tags 10 have been received (S205 "Yes") (S206). In this embodiment, AP20 stops broadcasting when it receives an ACK from each of the managed wireless electronic tags 10, thereby stopping the sending of instructions to the managed wireless electronic tags. Additionally, in step S205, if it is not confirmed that all instructions from the wireless electronic tags 10 have been received (S205 "No"), step S205 is executed again to confirm whether all instructions from the wireless electronic tags 10 have been received.

[0225] Then use Figure 18 The operation of AP20 will be explained.

[0226] like Figure 18 As shown, AP20 first uses GPS or the like to identify (confirm) the location in area B (S301). When AP20 moves from area A to area B along with the managed wireless electronic tag 10, AP20 identifies its location in area B using GPS or the like, thus enabling it to recognize its entry into area B. Alternatively, when AP20 does not move with the managed wireless electronic tag 10, it can accept instructions from the user of AP20 to identify (confirm) the managed wireless electronic tag 10 entering area B. Furthermore, AP20 can obtain the ID information of the managed wireless electronic tag 10 from a specific server or cloud server loaded by AP20 in area A via a wireless communication network.

[0227] Next, AP20 transmits a signal including an instruction to resume transmission to the managed wireless electronic tags 10 (S302). In this embodiment, AP20 broadcasts the signal including the instruction to resume transmission to the multiple managed wireless electronic tags 10 at the frequency of region B. Additionally... Figure 17 In the case where AP20 transmits a signal that includes a command to indicate a frequency change but does not include a command to indicate a frequency change, a signal that includes a command to indicate a frequency change can be transmitted instead of a signal that includes a command to indicate a frequency change.

[0228] Next, AP20 stops sending instructions to the managed wireless electronic tags after confirming that all instructions from the wireless electronic tags 10 have been received (S303 "Yes") (S304). In this embodiment, AP20 stops broadcasting when it receives an ACK from each of the managed wireless electronic tags 10, thereby stopping the sending of instructions to the managed wireless electronic tags. Furthermore, in step S303, if it is not confirmed that all instructions from the wireless electronic tags 10 have been received (S303 "No"), step S303 is executed again to confirm whether all instructions from the wireless electronic tags 10 have been received.

[0229] [3 Effects, etc.]

[0230] As described above, before moving to an area with a different frequency, the wireless electronic tag 10 in this embodiment receives instructions from a wireless access point using a carrier sensing function to change the frequency setting, and then stops transmitting to the wireless access point. Instruction reception continues on the new frequency, and an instruction to resume transmission is received from the wireless access point, thereby resuming transmission to the wireless access point.

[0231] Thus, through this embodiment, even an active wireless electronic tag lacking a data receiving unit can have its frequency changed by modifying the control program stored in its memory, utilizing the carrier sensing function of the wireless electronic tag. Furthermore, through this embodiment, the wireless electronic tag can simultaneously or alternately perform normal carrier sensing and carrier sensing for interpreting instructions sent by the wireless access point using its carrier sensing function.

[0232] More specifically, the wireless access point in this embodiment manages active wireless electronic tags that lack units for receiving data, identifies the current location of the wireless electronic tag, and can then issue instructions to the wireless electronic tag to change the frequency used by the wireless electronic tag. Furthermore, although the wireless electronic tag in this embodiment is an active wireless electronic tag that lacks units for receiving data, it can change the frequency used by the wireless electronic tag because it can interpret the instructions sent by the wireless access point using carrier sensing functionality.

[0233] While the wireless electronic tags and APs described above are based on embodiments, this disclosure is not limited to these embodiments. For example, the constituent elements described in this specification can be combined arbitrarily, and other embodiments implemented by removing some of the constituent elements can also be considered embodiments of this disclosure. Furthermore, variations that can be conceived by those skilled in the art by performing various modifications to the above embodiments without departing from the spirit of this disclosure, i.e., the meaning expressed by the statements in the claims, are also included in this disclosure.

[0234] Furthermore, the forms shown below may also be included within the scope of one or more forms disclosed herein.

[0235] (1) A portion of the constituent elements of the aforementioned AP can be a computer system consisting of a microprocessor, ROM, RAM, hard disk unit, display unit, keyboard, mouse, etc. The computer program is stored in the RAM or hard disk unit. The microprocessor performs its functions according to the computer program. The computer program here, in order to achieve the specified function, is composed of multiple combinations of instruction codes that show instructions for the computer.

[0236] (2) A portion of the components constituting the aforementioned AP can also be comprised of a single system LSI (Large Scale Integration). A system LSI is a multifunctional LSI manufactured by integrating multiple components onto a single chip; specifically, it is a computer system comprising a microprocessor, ROM, RAM, etc. The computer program is stored in the RAM. The microprocessor operates according to the computer program, thereby enabling the system LSI to perform its functions.

[0237] (3) A portion of the components constituting the AP described above can also be composed of an IC card or a single module that can be installed and removed from various devices. The IC card or module is a computer system composed of a microprocessor, ROM, RAM, etc. The IC card or module may also include the aforementioned multi-functional LSI. The IC card or module performs its functions by operating according to a computer program via a microprocessor. The IC card or module may also be tamper-proof.

[0238] (4) Furthermore, a component of the AP described above can also be implemented as a computer-readable recording medium on which the computer program or digital signal is recorded, such as a floppy disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, BD (Blu-ray Disc), semiconductor memory, etc. And it can also be the digital signal recorded in these recording media.

[0239] Furthermore, as part of the components of the aforementioned AP, the computer program or the digital signal can also be transmitted via electrical communication lines, wireless or wired communication lines, networks such as the Internet, data playback, etc.

[0240] (5) This disclosure may also be the method shown above. Furthermore, these methods may be implemented as a computer program or as a digital signal composed of said computer program.

[0241] (6) Furthermore, this disclosure may be a computer system having a microprocessor and a memory, wherein the memory stores the computer program described above, and the microprocessor operates according to the computer program.

[0242] (7) Furthermore, the program or the digital signal can be executed by an independent other computer system by recording it on the recording medium and transferring it, or by transferring the program or the digital signal via the network, etc.

[0243] (8) The above-described embodiments and the above-described variations can also be combined separately.

[0244] This disclosure can be used in active wireless electronic tags that do not have a unit for receiving data and wireless access points that manage the active wireless electronic tag.

[0245] Symbol Explanation

[0246] 1. Communication System

[0247] 10 Wireless electronic tags

[0248] 11 batteries

[0249] 12 sensors

[0250] 13 LSI Department

[0251] 20 AP

[0252] 130 RF Division

[0253] 131 Radio Wave Intensity Measurement Department

[0254] 132 Carrier Detection Unit

[0255] 133 Control Circuit

[0256] 134, 205 Memory

[0257] 134a Style Buffer

[0258] 135 Data Modulation Section

[0259] 201 Information Collection Department

[0260] 202 Identification Department

[0261] 203 Confirmation Department

[0262] 204 Signal Output Control Unit

[0263] 205 Memory

[0264] 1301 TX

[0265] 1302 RX

[0266] 1331 Style Matching Decision Unit

[0267] 1332 Explanation Department

[0268] 1333 RF Frequency Control Unit

[0269] 1334 RF Output Control Unit

[0270] 2041 Signal Transmission Unit

[0271] 2042 Signal stop part

Claims

1. A communication method, comprising a wireless access point and a communication system consisting of a plurality of wireless electronic tags, wherein the communication is conducted by one of the plurality of wireless electronic tags. The communication method includes: The carrier sensing procedure is performed in each specified period; In the transmission step, if no signal is detected during the carrier sensing process from a wireless electronic tag different from the wireless electronic tag to the wireless access point, and if the transmission is not in a stopped state, first data is transmitted to the wireless access point, the first data including information for uniquely identifying the wireless electronic tag, i.e., ID information; The instruction interpretation step involves detecting a signal during the execution of the carrier sensing, and if the signal is not a signal sent to the wireless access point by a wireless electronic tag different from the wireless electronic tag, interpreting the detected signal as a signal sent from the wireless access point, and interpreting the instructions included in the signal sent from the wireless access point. as well as The frequency change step involves changing the radio frequency of the signal transmitted by the one wireless electronic tag when the instruction interpretation step interprets the signal as containing an instruction to indicate a frequency change. In the sending step, If, during the instruction interpretation step, the signal is interpreted to include instructions to stop transmission and change the frequency, and no signal transmitted to the wireless access point by the different wireless electronic tags is detected during the carrier sensing, then second data is sent to the wireless access point. This second data is the first data supplemented with data indicating that the instruction has been received. In the frequency change step, If the instruction interpretation step interprets the signal as including instructions to stop transmission and change the frequency, then after the second data is transmitted, the radio frequency of the signal transmitted by the one wireless electronic tag is changed. The communication method further includes a control step in which, after the second data is transmitted in the transmission step, the execution of the transmission step is stopped only until the instruction interpretation step interprets that the signal transmitted from the wireless access point detected during the execution of the carrier sensing includes an instruction to indicate that transmission should be resumed.

2. A communication method, comprising a wireless access point and a communication system consisting of multiple wireless electronic tags, wherein the communication is conducted by one of the multiple wireless electronic tags. The communication method includes: The carrier sensing procedure is performed in each specified period; In the transmission step, if no signal is detected during the carrier sensing process from a wireless electronic tag different from the wireless electronic tag to the wireless access point, and if the transmission is not in a stopped state, first data is transmitted to the wireless access point, the first data including information for uniquely identifying the wireless electronic tag, i.e., ID information; The instruction interpretation step involves detecting a signal during the execution of the carrier sensing, and if the signal is not a signal sent to the wireless access point by a wireless electronic tag different from the wireless electronic tag, interpreting the detected signal as a signal sent from the wireless access point, and interpreting the instructions included in the signal sent from the wireless access point. as well as The frequency change step involves changing the radio frequency of the signal transmitted by the one wireless electronic tag when the instruction interpretation step interprets the signal as containing an instruction to indicate a frequency change. In the sending step, If, during the instruction interpretation step, the signal is interpreted to include an instruction to stop transmission, and no signal transmitted from the different wireless electronic tags to the wireless access point is detected during the carrier sensing, second data is sent to the wireless access point, wherein the second data is the first data supplemented with data indicating that the instruction has been received. The communication method further includes a control step in which, after the second data is sent in the sending step, the execution of the sending step is stopped only.

3. The communication method as described in claim 2, In the frequency change step, When the instruction interpretation step interprets the signal as containing an instruction to indicate a frequency change, the radio frequency of the signal transmitted by the one wireless electronic tag is changed. In the control step, when the radio frequency of the signal transmitted by the one wireless electronic tag is changed in the frequency change step, the execution of the transmission step is restarted.

4. The communication method as described in claim 1 or 2, The information indicating that the instruction was received is an ACK message, i.e., Acknowledgement.

5. A communication method, comprising a wireless access point and a communication system consisting of a plurality of wireless electronic tags, wherein the communication is conducted by one of the plurality of wireless electronic tags. The communication method includes: The carrier sensing procedure is performed in each specified period; In the transmission step, if no signal is detected during the carrier sensing process from a wireless electronic tag different from the wireless electronic tag to the wireless access point, and if the transmission is not in a stopped state, first data is transmitted to the wireless access point, the first data including information for uniquely identifying the wireless electronic tag, i.e., ID information; The instruction interpretation step involves detecting a signal during the execution of the carrier sensing, and if the signal is not a signal sent to the wireless access point by a wireless electronic tag different from the wireless electronic tag, interpreting the detected signal as a signal sent from the wireless access point, and interpreting the instructions included in the signal sent from the wireless access point. as well as The frequency change step involves changing the radio frequency of the signal transmitted by the one wireless electronic tag when the instruction interpretation step interprets the signal as containing an instruction to indicate a frequency change. The carrier sensing step includes the following steps: The strength calculation step calculates the strength of the signal received during the carrier sensing process. In the first detection step, during the period when the first averaged intensity exceeds the first threshold, it is determined that a signal sent to the wireless access point by a wireless electronic tag different from the wireless electronic tag is detected. The first averaged intensity is obtained by dividing the intensity calculated in the intensity calculation step into a first period and averaging it. as well as The second detection step determines that the detected signal is not a signal sent to the wireless access point by a wireless electronic tag different from the first wireless electronic tag by judging the pattern consisting of the number of the second averaged intensity exceeding the second threshold and the number below the second threshold. The second averaged intensity is obtained by dividing the intensity calculated in the intensity calculation step into a second period shorter than the first period and averaging it.

6. The communication method as described in claim 5, In the instruction interpretation step, The instructions included in the signal sent from the wireless access point are interpreted by combining the number of times the second average intensity of the pattern determined in the second detection step exceeds the second threshold and the number of times it falls below the second threshold.

7. A communication method, comprising a wireless access point and a communication system consisting of a plurality of wireless electronic tags, wherein the communication is conducted by one of the plurality of wireless electronic tags. The communication method includes: The carrier sensing procedure is performed in each specified period; In the transmission step, if no signal is detected during the carrier sensing process from a wireless electronic tag different from the wireless electronic tag to the wireless access point, and if the transmission is not in a stopped state, first data is transmitted to the wireless access point, the first data including information for uniquely identifying the wireless electronic tag, i.e., ID information; The instruction interpretation step involves detecting a signal during the execution of the carrier sensing, and if the signal is not a signal sent to the wireless access point by a wireless electronic tag different from the wireless electronic tag, interpreting the detected signal as a signal sent from the wireless access point, and interpreting the instructions included in the signal sent from the wireless access point. as well as The frequency change step involves changing the radio frequency of the signal transmitted by the one wireless electronic tag when the instruction interpretation step interprets the signal as containing an instruction to indicate a frequency change. In the carrier sensing step, the first carrier sensing step and the second carrier sensing step are executed alternately. The first carrier sensing step includes the following steps: The strength calculation step involves calculating the strength of the signal received during the carrier sensing process; and In the first detection step, during the period when the first averaged intensity exceeds a first threshold, it is determined that a signal transmitted to the wireless access point by a wireless electronic tag different from the stated wireless electronic tag is detected. The first averaged intensity is obtained by dividing the intensity calculated in the intensity calculation step into a first period and averaging it. The second carrier sensing step includes the following steps: The strength calculation step involves calculating the strength of the signal received during the carrier sensing process; and The second detection step determines that the detected signal is not a signal sent to the wireless access point by a wireless electronic tag different from the first wireless electronic tag by judging the pattern consisting of the number of the second averaged intensity exceeding the second threshold and the number below the second threshold. The second averaged intensity is obtained by dividing the intensity calculated in the intensity calculation step into a second period shorter than the first period and averaging it.

8. A communication method, which is a communication method conducted by a wireless access point in a communication system consisting of a wireless access point and multiple wireless electronic tags. The communication method includes: The ID information collection step involves collecting ID information, which is information used to uniquely identify each of the plurality of wireless electronic tags. The signal transmission step involves broadcasting, at each predetermined interval, a signal including an instruction to change the first frequency currently used by the plurality of wireless electronic tags to a second frequency for the plurality of wireless electronic tags; as well as The signal stopping step involves stopping the broadcast of the signal including the instruction upon confirming that information indicating the instruction has been received has been received from each of the plurality of wireless electronic tags. The communication method further includes: The identification step involves identifying the movement of the plurality of wireless electronic tags toward an area where the second frequency is required, thereby identifying that the plurality of wireless electronic tags have begun to move toward the area, wherein the second frequency is a frequency different from the first frequency currently used by the plurality of wireless electronic tags; as well as The confirmation step verifies that the multiple wireless electronic tags have entered the area. In the signal transmission step, When the identification step detects that the plurality of wireless electronic tags have begun to move toward the area, a signal is broadcast to the plurality of wireless electronic tags at predetermined intervals. This signal includes an instruction to change the first frequency currently used by the plurality of wireless electronic tags to the second frequency and an instruction to cease transmission. Furthermore, when the confirmation step confirms that the plurality of wireless electronic tags have entered the area, a signal including an instruction to resume transmission is broadcast to the plurality of wireless electronic tags at each specified interval.

9. A communication method, which is a communication method conducted by a wireless access point in a communication system consisting of a wireless access point and multiple wireless electronic tags. The communication method includes: The ID information collection step involves collecting ID information, which is information used to uniquely identify each of the plurality of wireless electronic tags. The signal transmission step involves broadcasting, at each predetermined interval, a signal including an instruction to change the first frequency currently used by the plurality of wireless electronic tags to a second frequency for the plurality of wireless electronic tags; as well as The signal stopping step involves stopping the broadcast of the signal including the instruction upon confirming that information indicating the instruction has been received has been received from each of the plurality of wireless electronic tags. The communication method further includes: The identification step involves identifying that the plurality of wireless electronic tags have begun to move toward an area where the second frequency is required, the second frequency being a frequency different from the first frequency currently being used by the plurality of wireless electronic tags; as well as The confirmation step verifies that the multiple wireless electronic tags have entered the area. Further in the signal transmission step, When it is detected in the identification step that the plurality of wireless electronic tags have begun to move toward the area, a signal including an instruction to stop transmitting is broadcast to the plurality of wireless electronic tags at each predetermined interval. When the confirmation step confirms that the plurality of wireless electronic tags have entered the area, a signal including an instruction to change the first frequency currently used by the plurality of wireless electronic tags to the second frequency is broadcast to the plurality of wireless electronic tags at each specified interval.

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