JP2009118076A - Radio communication apparatus, radio communication system, radio communication method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide radio communication apparatus that strikes a balance between the reduction of interference and the improvement of communication efficiency, by taking into consideration a communication load between a radio tag and communication parts. <P>SOLUTION: The radio communication apparatus 2A includes: a registration means 25 for registering the communication content between the radio tag 1 and a plurality of communication parts 21; a calculation means 26 for calculating the communication load of the communication content to a communication part for a channel assignment object by analyzing the communication content registered in the registration means 25; a decision means 27 for deciding whether the communication load to an object channel satisfies a predetermined communication load condition when the communication load calculated by the calculation means 26 is set to the object channel; and an assignment means 28 for assigning the one and same object channel to at least two communication parts for channel assignment objects when it is decided that the communication load to the object channel satisfies the predetermined communication load condition by the decision means 27. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless communication device that performs wireless communication with a wireless tag, a wireless communication system in which a plurality of wireless communication devices are arranged, a wireless communication method for wireless communication with a wireless tag, and wireless communication with a wireless tag. The present invention relates to a program for causing a computer to execute a process for the purpose.

  In a wireless system using a wireless tag such as an HF band (13.56 MHz band), the communication distance is as short as about 30 to 50 cm, and it is desired to increase the communication distance. Therefore, a wireless communication system using a UHF band (950 MHz band) and a microwave band (2.45 GHz band) having a long communication distance of 2 to 5 m with a target wireless tag performing wireless communication has been proposed. In Conventional Example 1, all the wireless communication devices are obtained by changing the wireless communication device to which the channels obtained by dividing the usable frequency band (for example, 9 channels in the high-power type UHF band) are assigned every specified time. An RFID (Radio Frequency IDentification) system that repeats the process of sequentially assigning channels to the network has been proposed (see, for example, Patent Document 1).

  In the RFID system disclosed in Patent Document 1, a channel is assigned to each radio signal transmitted from a certain radio communication device to a target radio tag in a time division manner. In the same time zone, one channel is assigned to the same channel. Only communication can take place. Therefore, reading information from a target wireless tag of another wireless communication device within a wide interference area (for example, a distance range of about 100 m to about 500 m when the UHF band is used as a radio frequency) and target wireless It is possible to increase the number of wireless communication devices beyond the number of allowed channels without adversely affecting (writing) information writing to the tag.

 Further, as a modification of the conventional example 1, the antenna includes a plurality of antennas and one control unit connected to the plurality of antennas, and the one control unit switches the plurality of antennas in a time-sharing manner and communicates with the wireless tag. A wireless communication device that performs the above has been known.

  In this conventional wireless communication apparatus, one control unit is shared by a plurality of antennas, and wireless radio waves are not simultaneously transmitted from the plurality of antennas. Therefore, there is an advantage that there is no interference between the antennas.

  Next, as a conventional example 2, a wireless tag reader / writer is proposed in which a group of instructions indicating the execution contents continuously performed in wireless communication is registered in advance and the group of instructions is called to execute wireless communication when necessary. (For example, refer to Patent Document 2).

  In the wireless tag reader / writer disclosed in Patent Document 2, it is not necessary for the wireless tag reader / writer to communicate with a higher-level control device for each process to exchange data, check the processing result, and the like. It is possible to simplify the contents of instructions from the device and execute a series of processing at high speed.

By the way, the radio wave used for radio communication between the radio communication device and the radio tag generally has an irregular pattern consisting of a communicable area and an incommunicable area, and in particular, the UHF band having a long communication distance. When used for wireless communication, the pattern of the communicable area and the incommunicable area becomes more irregular than when the HF band with a short communication distance is used for wireless communication. In this case, for example, in a factory production line, when a wireless tag that is attached to a pallet transported by a conveyor and moves relative to the wireless communication device approaches the wireless communication device, communication is temporarily performed from a communication disabled state. After entering the possible state, the communication temporarily becomes impossible again, and then the communication becomes possible again. Further, depending on the conditions, there may be areas where communication is impossible in the communication area. This phenomenon is particularly noticeable in the frequency band above the UHF band.
JP 2006-148258 A JP 2007-094889 A

  However, in the above-described conventional example 1, the wireless communication device to which channels are assigned in a one-to-one relationship is merely changed every predetermined time to perform channel assignment, and the communication data amount (communication load) for the wireless tag of the wireless communication device Therefore, when a channel is similarly assigned to a wireless communication device with a large amount of communication data and a wireless communication device with a small amount of communication data, the communication efficiency of the entire system may be reduced.

  Also in the conventional example 2, the wireless tag reader / writer (or antenna) set to transmit and receive a large amount of communication data and the wireless tag reader / writer (or antenna) set to transmit and receive a small amount of communication data. There is no proposal for automatically distinguishing the above and deriving an optimal interference reduction setting, and there is a problem that interference cannot be sufficiently reduced.

  Furthermore, there is no consideration of the phenomenon that the irregularity of the pattern of the communicable area and the incommunicable area becomes remarkable above the UHF band as described above. Even if it enters, there is a problem that the communication will stop until the RFID tag enters the communicable area again just by stacking the execution of the instruction group, so it takes time to complete the necessary access. There is a problem that the total processing time becomes long and the speeding up of access cannot be achieved.

  The present invention has been made in view of the above problems, and by considering the communication load of wireless communication with a wireless tag, a wireless communication device that achieves both reduction of interference and improvement of communication efficiency, and the wireless communication device It is a first object to provide a wireless communication system in which a plurality of communication devices are arranged, a wireless communication method for wirelessly communicating with a wireless tag, and a program for causing a computer to execute processing for wirelessly communicating with the wireless tag. To do.

  In addition to the purpose of deriving an optimal interference reduction setting, the present invention shortens the overall processing time of wireless communication and speeds up access even when a radio signal of the UHF band or higher is used. A second object of the present invention is to provide a wireless communication device that can be realized.

  In order to achieve the first object, a wireless communication device according to a first aspect of the present invention includes a communication unit that transmits / receives communication data to / from a wireless tag using radio waves in a specific frequency band, and is allowed in a specific frequency band. A controller unit to which a larger number of communication units than the number of channels being connected can be connected, the controller unit registering transmission data of the communication unit to the wireless tag corresponding to each communication unit; Calculating means for obtaining the amount of received data received by the communication unit from the wireless tag based on the transmission data registered by the registration unit and calculating the communication load for each communication unit from the amount of transmission data and the amount of received data And a storage means for storing a communication load condition for setting a communication load assigned to each channel, and a communication load for each channel is stored based on the communication load for each communication unit calculated by the calculation means. Allocating means for allocating channels for each communication unit so as to satisfy the communication load condition stored in the stage, and when the number of communication units larger than the number of allowed channels is used, By assigning the same channel to two or more communication units so that the communication load satisfies the communication load condition stored in the storage means, the number of channels assigned to the communication unit is made equal to or less than the allowed number of channels. And

  With this configuration, the allocating unit allocates the same channel to two or more communication units so that the communication load for each channel satisfies the communication load condition stored in the storage unit, so that the number of channels allocated to the communication unit is allowed. The number of channels can be less than or equal to. As described above, by considering the communication load of wireless communication with the wireless tag, it is possible to provide a wireless communication device that achieves both reduction of interference and improvement of communication efficiency. In this specification, “transmission / reception” means reception of communication data, and “interference” refers to communication data in the case where a plurality of communications are simultaneously performed in the frequency band of the same channel. This means that there is some influence on transmission / reception, and specifically means that reception data cannot be received.

  According to a second aspect of the present invention, there is provided the wireless communication device according to the first aspect, wherein the wireless communication device is a total amount of communication data transmitted or received between the wireless tag and the communication unit or a required communication time.

  With such a configuration, by using the total amount of communication data or the required communication time as the communication load, different channels are allocated to communication units having a large communication data amount or a long communication required time, and the communication data amount is small or The same channel can be allocated to communication units having a short communication time in a time division manner, and efficient access can be made in consideration of the balance between the number of channels and the time division processing amount.

  In the wireless communication device according to the third invention, in the second invention, the communication load condition is that a difference between a maximum communication load and a minimum communication load is within a predetermined range among communication loads for each channel. It is the conditions to become.

  With such a configuration, since the communication load of each channel falls within a certain variation range, wireless communication with high communication efficiency is possible with the number of channels equal to or less than the allowable number of channels.

  According to a fourth aspect of the present invention, in the second aspect of the invention, the communication load condition is a means for allocating a plurality of communication units more than the plurality of channels to a plurality of channels equal to or less than the permitted number of channels. When allocating according to the above, in all combinations of allocation between a plurality of channels and a plurality of communication units, the maximum communication load among the communication loads for each channel in each combination is obtained, and the maximum communication load of each combination is determined. Among them, a condition that a maximum communication load is minimum is extracted, and a condition is that a plurality of communication units are allocated to a plurality of channels by the combination.

  With such a configuration, all combinations are brute-forced, and a communication load is most uniform among them, and a plurality of communication units can be assigned to a plurality of channels, thereby enabling more efficient wireless communication. .

According to a fifth aspect of the present invention, in the first to fourth aspects, the controller unit further assigns the communication load condition if the communication load condition is not satisfied when assigning the channel to each communication unit by the assigning means. An informing means for informing that it is not satisfied is provided.

  With such a configuration, it is possible to notify the user that there is a communication unit that has a large communication load and does not satisfy the communication load condition set by the user.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the wireless communication device further notifies which channel does not satisfy the communication load condition.

  With such a configuration, the user can be notified of which communication unit does not satisfy the predetermined communication load condition set by the user.

  According to a seventh aspect of the present invention, in the sixth aspect of the invention, the notifying unit notifies which of the transmission data of the communication unit, the communication load condition, and the number of communication units to be used should be changed. It is characterized by being.

  With such a configuration, the user can know items to be changed to satisfy the communication load condition.

  According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the specific frequency band is a UHF band.

  With such a configuration, a channel with a limited number of UHF bands having a long communication distance can be effectively allocated to a communication unit having a larger number of channels.

  In order to achieve the second object, according to a ninth aspect of the present invention, in the wireless communication device according to any one of the first to eighth aspects, the controller unit further moves relative to the communication unit. Detecting means for detecting whether or not the communication unit is in a communicable area where communication data can be transmitted / received to / from the communication unit, and the communication part can communicate with the wireless tag by the detection unit When it is detected that it exists in the area, transmission of transmission data to the wireless tag is started, and the wireless tag is detected by the detecting means during transmission of transmission data or reception of reception data from the wireless tag for transmission data. When it is detected that the communication area has been entered, transmission control means for interrupting transmission of transmission data to the wireless tag and transmission data transmission to the wireless tag by the transmission control means. If the detection means detects that another wireless tag exists in the communicable area of the other communication unit assigned to the same channel as the communication unit, the other communication unit And start control means for starting transmission of other transmission data to another wireless tag.

  With such a configuration, when a detecting unit detects that a wireless tag that moves relatively enters a communication impossible area while a certain communication unit is transmitting transmission data, the wireless tag is placed in a communication enabled area. Rather than waiting for retransmission of transmission data until it moves, another communication unit starts transmitting transmission data to another wireless tag that exists in the communicable area, so the time division processing is made more efficient Can be planned.

  According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the transmission control means further detects that the wireless tag whose transmission data has been interrupted by the detection means has reentered the communicable area of the communication unit. The reception of reception data from another wireless tag for other transmission data detected and started by the start control means is completed, or another wireless tag has entered a communication impossible area of another communication unit When this is detected by the detecting means, the transmission of transmission data is resumed with respect to the communication unit in which transmission of transmission data has been interrupted.

  With such a configuration, it is possible to shorten the processing time of the entire wireless communication apparatus while reliably transmitting the transmission data registered in advance, thereby achieving high-speed access.

  In a tenth aspect of the wireless communication apparatus according to the eleventh aspect of the invention, the transmission data registered in the registration means is a group of instructions consisting of a plurality of read commands or write commands for the wireless tag, or a combination of read commands and write commands. The transmission control means further receives the received data from the wireless tag in the command group of the transmission data when resuming transmission of the transmission data to the communication unit for which transmission of the transmission data has been interrupted. Restarts transmission from an incomplete instruction.

  With such a configuration, when transmission of transmission data is resumed, transmission of transmission data is resumed because transmission is resumed from an instruction in which reception of reception data from the wireless tag is not completed in the transmission data instruction group. It is possible to increase the communication efficiency as a whole.

A wireless communication method according to a twelfth aspect of the invention is more than a wireless communication device that transmits / receives communication data to / from a wireless tag using radio waves in a specific frequency band and the number of channels allowed in the specific frequency band. A wireless communication system having a computing device connectable to a plurality of wireless communication devices, the computing device registering transmission data of the wireless communication device to the wireless tag in association with each wireless communication device; Based on the transmission data registered by the registration means, the amount of reception data received by the wireless communication device from the wireless tag is obtained, and the communication load for each wireless communication device is calculated from the amount of transmission data and the amount of reception data Based on a calculation means, a storage means for storing a communication load condition for setting a communication load assigned to each channel, and a communication load for each wireless communication device calculated by the calculation means , And a assigning means for communicating the load for each channel to allocate channels to the respective wireless communication devices to satisfy the stored communication load condition in the storage means,
When a larger number of wireless communication devices than the allowed number of channels are used, the allocating unit assigns the two or more wireless communication devices such that the communication load for each channel satisfies the communication load condition stored in the storage unit. By assigning the same channel, the number of channels assigned to the wireless communication apparatus is made equal to or less than the allowed number of channels.

  With such a configuration, the assigning means assigns the same channel to two or more wireless communication apparatuses so that the communication load for each channel satisfies the communication load condition stored in the storage means. Therefore, the number of channels assigned to the wireless communication apparatus Can be less than or equal to the number of allowed channels. Thus, by considering the communication load with the wireless tag, it is possible to provide a wireless communication system that achieves both reduction of interference and improvement of communication efficiency.

  The wireless communication method according to the thirteenth aspect of the invention is a communication unit that transmits / receives communication data to / from a wireless tag using radio waves in a specific frequency band, and a number that is larger than the number of channels allowed in the specific frequency band. A wireless communication method used in a wireless communication apparatus comprising a controller unit having a storage unit for storing a communication load condition for setting a communication load to be assigned for each channel. Based on the registration process for registering the transmission data of the communication unit to each communication unit and the transmission data registered by the registration step, the amount of received data received from the wireless tag to the communication unit is obtained and transmitted Calculation process for calculating the communication load for each communication unit from the amount of data and the amount of received data, and calculation when more communication units than the allowed number of channels are used Based on the communication load for each communication unit calculated as described above, the same channel is allocated to two or more communication units so that the communication load for each channel satisfies the communication load condition stored in the storage unit. And an allocating step of setting the number of channels to be less than or equal to the allowed number of channels.

  With such a configuration, since the assigning step assigns the same channel to two or more wireless communication devices so that the communication load for each channel satisfies the communication load condition stored in the storage unit, the number of channels assigned to the wireless communication device Can be less than or equal to the number of allowed channels. Thus, by considering the communication load with the wireless tag, it is possible to provide a wireless communication system that achieves both reduction of interference and improvement of communication efficiency. Note that the storage of the communication load condition by the storage unit may be performed any time before the allocation step.

  According to a fourteenth aspect of the present invention, there is provided a communication unit that transmits / receives communication data to / from a wireless tag using radio waves in a specific frequency band, and a communication whose number is larger than the number of channels permitted in the specific frequency band. A program that causes a computer mounted on a controller unit to execute processing in a wireless communication device including a controller unit having a storage unit that stores a communication load condition for setting a communication load assigned to each channel. The registration processing for registering the transmission data of the communication unit to the wireless tag corresponding to each communication unit, and the transmission data registered by the registration processing, the received data received by the communication unit from the wireless tag Calculation processing to calculate the communication load for each communication unit from the amount of transmitted data and the amount of received data, and the number of allowed channels When a greater number of communication units are used, two or more communication loads for each channel satisfy the communication load condition stored in the controller unit based on the communication load for each communication unit calculated by the calculation process. By allocating the same channel to the communication unit, the computer is caused to execute an assignment process for setting the number of channels assigned to the communication unit to be equal to or less than the allowable number of channels.

  With such a configuration, since the assignment process assigns the same channel to two or more wireless communication devices so that the communication load for each channel satisfies the communication load condition stored in the storage unit, the number of channels assigned to the wireless communication device Can be less than or equal to the number of allowed channels. In this way, by considering the communication load with the wireless tag, it is possible to provide a program for a wireless communication apparatus that achieves both reduction of interference and improvement of communication efficiency. Note that the storage of the communication load condition by the storage unit may be performed any time before the allocation process.

  According to the present invention, by considering the communication load of wireless communication with a wireless tag, a wireless communication device that achieves both reduction of interference and improvement of communication efficiency, and wireless communication in which a plurality of the wireless communication devices are arranged A system, a wireless communication method for wirelessly communicating with a wireless tag, and a program for causing a computer to execute processing for wirelessly communicating with the wireless tag can be provided.

  Further, according to the present invention, in addition to the above-described effects, even when a radio signal other than the UHF band is used, the radio communication time can be shortened and the access speed can be increased. A communication device can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. Note that elements having the same or similar configuration or function are denoted by the same or similar reference numerals throughout the drawings referred to in the description of each embodiment, and detailed description thereof is omitted.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration example of a wireless communication device 2A according to Embodiment 1 of the present invention. In FIG. 1, a wireless communication device 2A is applied to a production line in a factory, for example, and a plurality of wireless tags 1a and 1b attached in advance to an article conveyed on a conveyance path of the production line or a pallet holding the article. ,..., 1n (collectively indicated by reference numeral 1), transmission / reception of radio signals of each channel (9 channels in total) obtained by frequency-dividing, for example, a UHF band (950 MHz band) as a specific frequency band Perform non-contact communication by. In addition, since an interference phenomenon occurs even at a frequency lower than the UHF band, a similar configuration can be used. The same applies to the following embodiments.

  FIG. 2 is a block diagram illustrating a configuration example of the wireless tag 1. In FIG. 2, the wireless tag 1 includes an IC chip 11 and an antenna 12 obtained by molding a metal film having both ends connected to the IC chip 11. FIG. 3 is a plan view illustrating one structural example of the wireless tag 1 for illustrating one structural example of the antenna 12. In FIG. 3, a resonance circuit 121 in which a resonance frequency is set to be in the UHF band is formed on a flat dielectric substrate 122 in a part of the antenna 12.

  Referring again to FIG. 2, IC chip 11 includes a CPU 13, a power supply circuit 14, a transmission / reception circuit 15, and a memory 16. The CPU 13 executes processing for reading communication data including tag identification information unique to the wireless tag 1 stored in the memory 16 from the memory 16 and writes the communication data transmitted from the transmission / reception circuit 15 to the memory 16. Execute the process. The power supply circuit 14 is connected to the antenna 12, generates power using radio waves received by the antenna 12, and supplies the generated power to the CPU 13 and the transmission / reception circuit 15. The transmission / reception circuit 15 is composed of a high-frequency circuit element, and under the control of the CPU 13, transmits a radio signal obtained by modulating communication data read from the memory 16 to the antenna 12 and receives the radio signal received by the antenna 12. Communication data obtained by demodulating the signal is sent to the CPU 13. The communication data referred to in the present invention is a general term for data transmitted and received between the wireless tag 1 and the wireless communication device 2A. Communication data sent from the wireless communication device 2A to the wireless tag 1 is called transmission data. Communication data sent from the wireless tag 1 to the wireless communication device 2A is referred to as reception data.

  Referring again to FIG. 1, the wireless communication device 2A includes a plurality of communication units 21a, 21b,..., 21n (collectively indicated by reference numeral 21) and a controller unit 40. The controller unit 40 includes switching means 22. A transmission / reception circuit 23, a control means 24A, and a registration means 25. The control unit 24A includes a calculation unit 26, a determination unit 27, and an allocation unit 28.

  The plurality of communication units 21 function as an antenna, transmit a wireless signal to the wireless tag 1, and receive a wireless signal from the wireless tag 1. The plurality of communication units 21 has a larger number than the number of channels in the UHF band (9), and an area (UHF band) in which radio waves transmitted from one communication unit can be received by other communication units. Then, it is arranged within a communication distance range of about 100 m to about 500 m (so-called interference region). FIG. 4 is a plan view showing one structural example of one of the plurality of communication units 21. As shown in FIG. 4, each of the plurality of communication units 21 includes a disk-shaped conductor 211 and one end 212 a connected to the conductor 211 to form a feeding point, and the other end (not shown) electrically to the switching unit 22. And a coaxial cable 212 connected thereto.

  The switching means 22 functions as a high-frequency switch, and is controlled in operation by the control means 24A. The radio signal from the transmission / reception circuit 23 is switched in a time-sharing manner and sent to the plurality of communication units 21a, 21b,. The radio signals from the units 21a, 21b,..., 21n are switched to time division and sent to the transmission / reception circuit 23.

  The transmission / reception circuit 23 is composed of a high-frequency circuit element, sends a radio signal obtained by modulating communication data to the switching means 22, and demodulates the radio signal sent from the switching means 22. This is sent to the control means 24A.

The control unit 24A includes a CPU and an external I / F, and controls operations of the registration unit 25, the calculation unit 26, the determination unit 27, and the allocation unit 28 in consideration of the communication load on the plurality of communication units 21. Then, channel assignment processing for assigning each channel to the plurality of communication units 21 is executed. Here, the communication content is the content of communication data transmitted / received between the communication unit 21 and the wireless tag, and the communication load is the total amount of communication data transmitted / received between the wireless tag and the communication unit or It is the time required for communication. By using the communication data amount or the required communication time as a communication load, different channels are allocated to communication units having a large communication data amount or a long communication time, and further a communication unit having a small communication data amount or a short communication time. By assigning the same channel to each other in a time division manner, efficient access is possible in consideration of the balance between the number of channels and the time division processing amount. The channel assignment process will be described later in detail.

  In addition, the control unit 24A receives transmission data to the plurality of wireless tags 1 from an external device (not shown), and registers the received transmission data in the registration unit 25. The control unit 24A switches the switching unit 22 to time division, reads out the instruction included in the transmission data of the communication unit 21 after switching registered in the registration unit 25 at the same timing as the switching timing of the switching unit 22, Processing contents in accordance with the read command are sent to the transmission / reception circuit 23 in a time division manner, and received data is received from the transmission / reception circuit 23 in a time division manner and registered in the registration means 25, and the received reception data is received from an external device (not shown). Send to.

The control unit 24 </ b> A receives a communication load condition from an external device (not shown) and stores it in a storage unit included in the registration unit 25. Here, the communication load condition may be a predetermined threshold for the total communication load in the allocation target channel, or a predetermined range of variation between the channels of the total communication load in the allocation target channel. When a predetermined threshold value is used as the communication load condition, the predetermined threshold value can be freely set by the user, so that the communication efficiency allowed by the user can be ensured. Further, when a predetermined variation range is used as the predetermined communication load condition, the communication units can be equally allocated to the channels according to the communication load, so that the efficiency of communication as the entire apparatus can be achieved.
Still further, the communication load condition is that when assigning a plurality of communication units having a number larger than the plurality of channels to a plurality of channels equal to or less than the number of allowed channels,
In all combinations of assignments between a plurality of channels and a plurality of communication units, the maximum communication load in the communication load for each channel in each combination is obtained, and the maximum communication load in each combination is determined. A condition that extracts a combination that minimizes the communication load and allocates a plurality of communication units to a plurality of channels by the combination may be used. In this case, the communication load is most uniformed among all the combinations and assigned to the channels, so that more efficient wireless communication is possible.

  The registration unit 25 also functions as a storage unit, registers communication contents of wireless communication sent from an external device (not shown) under operation control by the control unit 24A, and stores predetermined communication load conditions. The communication data to be sent to an external device (not shown) is stored.

  The calculation unit 26 reads the transmission data registered in the registration unit 25 under the operation control by the control unit 24A, and obtains the amount of reception data received by the communication unit from the wireless tag from the read transmission data. The communication content is analyzed by the above, and the communication load on the communication unit 21 to be assigned a channel is calculated.

  The determination unit 27 determines whether or not the total communication load for the target channel satisfies a predetermined communication load condition when the communication load calculated by the calculation unit 26 is set as the target channel. The communication load condition is read from the registration unit 25 and set in the determination unit 27 under the operation control by the control unit 24A.

  The allocation unit 28 allocates the same target channel to at least two communication units 21 to be allocated to a channel when the determination unit 27 determines that the total communication load for the target channel satisfies a predetermined communication load condition. . The identification information of the assigned target channel (for example, jth channel, j = 1, 2,..., 9) is the identification information of the communication unit 21 to which the target channel is assigned (for example, the i th communication unit, i = 1, 2,..., N) and registered in the registration means 25 under the operation control by the control means 24A.

  Next, channel assignment processing will be described.

  FIG. 5 is a flowchart showing each processing step of channel assignment processing by control means 24A of radio communication apparatus 2A according to Embodiment 1 of the present invention. In FIG. 5, first, the control unit 24A sets 1 to a variable i indicating what number communication unit and a variable j indicating what number channel (i ← 1, j ← 1: Step S501). Next, the control unit 24A causes the calculation unit 26 to calculate a communication load of communication contents from transmission data or the like for the i-th communication unit registered in the registration unit 25 (step S502).

  Next, when the communication load calculated in step S502 is set to the j-th channel, the control unit 24A determines whether or not the total communication load for the j-th channel satisfies a predetermined communication load condition. 27 (step S503). When the determination unit 27 determines that the total communication load for the j-th channel satisfies the predetermined communication load condition (step S503: Yes), the control unit 24A branches the process to step S504 to assign the allocation unit. 28, the i-th communication unit is assigned to the j-th channel, the value of the variable i is incremented (i ← i + 1: step S505), and the process proceeds to step S507.

  Next, the control unit 24A determines whether or not the value of the variable i is larger than the number of communication units (step S507). When it is determined that the value of the variable i is larger than the number of communication units (step S507: Yes), the process is terminated. On the other hand, when the control unit 24A determines that the value of the variable i is equal to or less than the number of communication units (step S507: No), the process proceeds to step S508, and whether or not the value of the variable j is larger than the number of channels. Determine whether. When the control unit 24A determines that the value of the variable j is larger than the number of channels (step S508: Yes), the control unit 24A ends the process. On the other hand, when the control unit 24A determines that the value of the variable j is equal to or less than the number of channels (step S508: No), the process returns to step S502.

  When the control unit 24A determines that the total communication load for the j-th channel does not satisfy the predetermined communication load condition (step S503: No), the control unit 24A increments the value of the variable j (j ← j + 1: step S506). Then, the process proceeds to step S507. Since the processing contents in steps S507 and S508 have already been described, description thereof will be omitted. As described above, the channel assignment process is executed by the control means 24A.

  As described above, according to the first embodiment of the present invention, when the determining unit 27 determines that the total communication load for the target channel satisfies the predetermined communication load condition, the allocating unit 28 Since the same target channel is allocated to at least two target communication units, the number of channels allocated to the plurality of communication units 21 can be made equal to or less than the number of channels in a specific frequency band. By considering the communication load of wireless communication with the wireless communication device 1, it is possible to provide the wireless communication device 2 </ b> A that achieves both reduction in interference and improvement in communication efficiency. The predetermined communication load condition here refers to the above-described threshold value, condition for variation, and the like. The registration means described in the means for solving the problem is realized as the registration means 25, the calculation means is realized as the calculation means 26, the storage means is realized while being included in the registration means 25, and the assignment means is the determination means 27. And the assigning means 28.

  In the first embodiment, the case where the registration unit 25 is provided outside the control unit 24A has been illustrated and described. However, the present invention is not limited to this configuration, and the registration unit 25 is provided inside the control unit 24A. May be.

  In the first embodiment, the switching unit 22 switches the radio signal to the plurality of communication units 21 assigned to the same channel in a time-sharing manner so as to perform radio communication with the radio tag 1. Although configured, it is also possible to configure so that radio signals are transmitted simultaneously only to communication units assigned to different channels.

  For example, FIG. 6 is a time chart showing the channel assignment status assigned to satisfy the communication load condition. In FIG. 6, the communication load is indicated by the communication time for the communication unit 21. “Antenna No.” is used as information for identifying the communication unit 21. As shown in FIG. 6, the channel assignment process is executed so that the total communication time in each channel does not exceed the reference time 61 set by the user. Even when the priorities are assigned in descending order, channel assignment is performed so that the reference time 61 is not exceeded, so that interference can be reduced while improving communication efficiency.

(Embodiment 2)
FIG. 7 is a block diagram showing a configuration example of the wireless communication device 2B according to Embodiment 2 of the present invention. The second embodiment includes a control unit 24B to which a notification unit 29 is added instead of the control unit 24A of the first embodiment. Since other configurations are the same as those of the first embodiment, description thereof will be omitted, and the function of the notification unit 29 and the channel assignment process when the notification unit 29 is added will be mainly described below.

  In FIG. 7, the determination unit 27 determines that the total communication load for the target channel does not satisfy the predetermined communication load condition, and the control unit 24B determines that there is a communication unit to which no channel is assigned. In this case, the notification unit 29 notifies the user that there is a communication unit to which no channel is assigned. In addition, the identification information (for example, name or number) of the corresponding communication unit that is not assigned, and the fact that the communication load of the communication content for the communication unit that has not been assigned is large and does not satisfy the predetermined communication load condition set by the user You may notify a user.

  In addition, the notification unit 29 notifies that at least one of the communication contents of the communication unit to be allocated to a channel, a predetermined communication load condition, and the number of communication units to be used is required. Thereby, in order to assign a channel to all the communication parts 21, it can notify a user that the conditions set by the user need to be changed.

  Further, the notification unit 29 notifies the communication content of the communication unit to be allocated to the channel, the predetermined communication load condition, and the change content of the number of communication units used for wireless communication. Thus, in order to assign channels to all the communication units, the user is informed of which conditions should be changed to what extent, and the user can perform tuning again by simply resetting the conditions.

  Next, channel assignment processing will be described.

  FIG. 8 is a flowchart showing each processing step of the channel assignment processing by the control unit 24B of the wireless communication apparatus 2B according to Embodiment 2 of the present invention. In FIG. 8, the same processing steps as those in FIG. 5 referred to in the description of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 8, when the control unit 24B determines that the value of the variable i is larger than the number of communication units (step S507: Yes), the process is terminated. When the control unit 24B determines that the value of the variable i is equal to or less than the number of communication units (step S507: No), and determines that the value of the variable j is greater than the number of channels (step S508: Yes), step S801. Proceed with the process.

  The control unit 24B is used as notification information for identification information of a communication unit that has not been assigned, communication content (transmission data or corresponding reception data) of a communication unit that is a channel assignment target, a predetermined communication load condition, and wireless communication. The notification means 29 is notified of the fact that at least one condition change is necessary among the number of communication units to be performed and the content of the condition change (step S801), and the process is terminated.

  As described above, the channel assignment process is executed by the control means 24B.

  As described above, according to the second embodiment of the present invention, in addition to the advantages of the first embodiment, which communication unit has failed in channel allocation, which condition should be changed, The user can be notified of how much the condition is changed and how much the channel can be assigned to all the communication units.

  In the second embodiment, the channel assignment process is not executed when the predetermined communication load condition is not satisfied. However, the channel assignment process may be executed even when the communication load condition is not satisfied. good. Thereby, the channel which does not satisfy | fill communication load conditions can be confirmed, and the alerting | reporting means 29 can alert | report which channel is not satisfy | filling communication load conditions.

  For example, FIG. 9 is a time chart showing a channel assignment situation when the communication load condition is not satisfied. In FIG. 9, as in FIG. 6, the communication load is indicated by the communication time with respect to the communication unit 21. “Antenna No.” is used as information for identifying the communication unit 21. As shown in FIG. 9, the channel allocation process is executed so that the total communication time in the channel 9 exceeds the reference time 61 set by the user. Therefore, it is possible to reliably detect and notify that channel 9 has failed in channel 9, that is, antenna 9-1, which condition should be changed, and how much should be changed, It is possible to inform the user whether channels can be assigned to all the communication units 21.

  If the predetermined communication load condition is not satisfied, the channel is assigned under the second communication load condition close to the user's communication load condition, and as a result, the channel that does not satisfy the initial communication load condition is clearly indicated. Also good.

  In this case, for example, by setting two thresholds for communication load conditions, normal use and emergency use, and even if the normal threshold value is exceeded, the channel assignment process is executed when the emergency threshold value is not exceeded, It is possible to improve the efficiency of the assignment work without re-performing the channel assignment process.

  For example, FIG. 10 is a time chart showing a channel assignment situation when two threshold values of communication load conditions are provided. In FIG. 10, similarly to FIG. 6, the communication load is indicated by the communication time for the communication unit 21. “Antenna No.” is used as information for identifying the communication unit 21. As shown in FIG. 10, the channel allocation process is executed so that the total communication time in the channel 9 exceeds the reference time 61 set by the user. However, the channel allocation process is executed so as not to exceed the emergency reference time 62 set by the user, and it is reliably detected that the channel allocation has failed in the channel 9, that is, the antenna 9-1. In addition, it is possible to make a notification, and it is also possible to communicate by using the executed channel assignment as it is.

(Embodiment 3)
FIG. 11 is a block diagram showing a configuration example of a wireless communication apparatus 2C according to Embodiment 3 of the present invention. The third embodiment includes a control unit 24C in which a detection unit 30 and an instruction execution control unit 31 are added instead of the control unit 24B of the second embodiment. Since the other configuration is the same as that of the second embodiment, the description thereof will be omitted. In the following, the functions of the detection unit 30 and the instruction execution control unit 31 and the detection unit 30 and the instruction execution control unit 31 are mainly added. The instruction execution process will be described.

  In FIG. 11, the communication content (transmission data) registered in the registration means 25 can be a plurality of read commands or write commands for the wireless tag, or a command group consisting of a combination of read commands and write commands. As a result, if a series of processing contents for each communication unit 21a, 21b,..., 21n is registered in advance in the registration means 25 as an instruction group, the instruction group is immediately called when necessary to execute transmission / reception of a series of communication data. can do.

  The detection unit 30 determines whether the wireless tag 1 that moves relative to the communication unit 21 exists in a communicable region where wireless communication with the communication unit 21 is possible or is impossible. To detect. The detecting unit 30 receives the wireless signal transmitted from the communication unit 21 to the wireless tag 1, and the transmission / reception circuit 23 determines whether the wireless unit 1 has received the wireless signal transmitted from the wireless tag 1. Whether or not the wireless tag 1 exists in the communicable area or in the incommunicable area is detected based on whether or not communication data has been sent from.

The command execution means 31 includes a transmission control means (not shown) and a start control means. The transmission control unit transmits to the wireless tag 1a when the detection unit detects that the wireless tag 1 (for example, the wireless tag 1a) exists in the communicable area of the communication unit 21 (for example, the communication unit 21a). When transmission of data is started and the detection unit detects that the wireless tag 1a has entered a non-communication area during transmission of transmission data or reception of data received from the wireless tag 1a for transmission data The transmission of transmission data to the wireless tag 1a is interrupted. When transmission of transmission data to the wireless tag 1a is interrupted by the above-described transmission control means, the start control means is connected to another communication unit 21 (for example, the communication unit 21b) assigned to the same channel as the communication unit 21a. When the detection unit detects that another wireless tag (for example, wireless tag 1b) exists in the communicable area, transmission of other transmission data from the other communication unit 21b to the other wireless tag 1b is started. To do.

  The command execution control means 31, when the communication unit 21 a is executing transmission data transmission, detects that the wireless tag 1 a moving by the detection means 30 has entered the non-communication area, the wireless tag 1 a Rather than waiting for transmission of transmission data until it moves to the communicable area, control is performed to start radio communication by another communication unit 21b for another radio tag 1b existing in the communicable area. The efficiency of the time division process can be improved.

  Further, the transmission control means of the instruction execution control means 31 detects by the detection means 30 that the communication part 21a for which transmission of transmission data has been interrupted and the wireless tag 1a that was the object of communication have reentered the communicable area. The reception of the received data from the other wireless tag 1b with respect to the other transmission data started by the start control means is completed, or the other wireless tag 1b cannot communicate with the other communication unit 21b. When the detection means 30 detects that it has entered the area and the transmission of the transmission data of the other communication unit 21b is interrupted, the transmission of the transmission data was interrupted with respect to the communication unit 21a. Control to resume transmission of transmission data. In particular, when the transmission data is an instruction group including a plurality of read commands or write commands, or a combination of a read command and a write command, transmission is performed from a command that has not been received from the wireless tag 1a. Resume. As a result, the processing time of the entire wireless communication apparatus can be shortened while reliably executing a pre-registered command group, so that high-speed access can be achieved.

  Next, transmission data transmission processing will be described by taking as an example a case where an instruction group is registered in the communication unit 21 in particular. Here, reception of transmission data that is a write command or a read command and reception data corresponding to the transmission data is collectively referred to as “command execution”.

  FIG. 12 shows, in the command execution process by the control unit 24C of the wireless communication device 2C according to the third embodiment of the present invention, the transmission process to the other communication unit 21b with a focus on the transmission process of the specific communication unit 21a. It is a flowchart which shows a process. In FIG. 12, first, the control unit 24C determines whether or not an instruction group is registered in the registration unit 25 (step S1201). When the control unit 24C determines that the instruction group is not registered in the registration unit 25 (step S1201: No), the control unit 24C ends the process.

  On the other hand, when the control unit 24C determines that the instruction group is registered in the registration unit 25 (step S1201: Yes), the wireless tag 1a that performs wireless communication with the communication unit 21a in which the instruction group is registered is in communication. It is determined whether or not it exists in the possible area (step S1202). When the control unit 24C determines that the corresponding wireless tag 1a exists in the communicable area (step S1202: Yes), the control unit 24C permits execution of the registered instruction group (step S1203).

  Next, the control unit 24C determines whether or not the execution of all instruction groups has been completed (step S1204), and determines that the execution of all instruction groups has not ended (step S1204: No). Then, it is determined whether or not the wireless tag 1a has moved and entered the communication impossible area (step S1205). When it is determined that the wireless tag 1a has entered the communication impossible area (step S1205: Yes), the instruction group is executed. Is interrupted (step S1206).

  Next, the control unit 24C determines whether or not another wireless tag 1b exists in the communicable area of the other communication unit 21b (S1207), and the other wireless tag 1b can communicate with the other communication unit 21b. If it is determined that it exists in the area (S1207: Yes), execution of another instruction group is permitted (S1208). If it does not exist (S1207: No), the process proceeds to the next process without permitting execution. Further, it is determined whether or not the wireless tag 1a in which the execution of the instruction group has been suspended has moved and reentered the communicable area of the communication unit 21a (step S1209), and the wireless tag 1a has reentered the communicable area. If it is determined (step S1209: Yes), it is determined whether or not another wireless tag 1b has entered a non-communication area of another communication unit 21b, or execution of another command group has ended ( In step S1210), if the determination is true, execution of instructions for which reception data reception has not been completed is resumed from the interrupted instruction group (step 1211), and the process returns to step S1204. The above processing is repeated. In each determination step of S1209 and S1210, the determination is repeated until the determination becomes true. When the control unit 24C determines that the execution of all the instruction groups has been completed (step S1204: Yes), the process is ended.

  As described above, the instruction execution process is executed by the control means 24C.

  As described above, according to the third embodiment of the present invention, in addition to the advantages of the second embodiment, a plurality of read commands or write commands among the transmission data for each communication unit 21a, 21b,. Alternatively, if a combination of a read command and a write command is registered in advance in the registration means 25 as a command group, the command group can be immediately called when necessary to execute continuous transmission, and a moving wireless tag When it is detected that 1a has entered the non-communicable area, it does not wait for the execution of the instruction group until the wireless tag 1a comes to the communicable area, but another wireless tag 1b existing in the communicable area Since another communication unit 21b starts executing the instruction group, it is possible to improve the efficiency of the time division processing. Furthermore, since the processing time of the entire wireless communication apparatus can be shortened while reliably executing a pre-registered instruction group, high-speed access can be achieved.

  In the third embodiment, the case where the instruction group is registered in the communication units 21a and 21b in FIG. 12 has been described. However, the present invention is not limited to this, and even if the transmission data is a single instruction. Needless to say, the control method described above can be applied. Further, although the configuration in which the notification unit 29 is provided in the control unit 24C is illustrated and described, the present invention is not limited to this configuration, and a configuration in which the notification unit 29 is not provided is also within the scope of the present invention.

(Embodiment 4)
FIG. 13 is a block diagram showing an example of the overall configuration of a radio communication system according to Embodiment 4 of the present invention. In FIG. 13, the wireless communication system according to the fourth embodiment is applied to, for example, production lines 1001a, 1001b, and 1001c in a factory, and a plurality of wireless communication devices 2D and operations connected to the plurality of wireless communication devices 2D. Device 1002. In the fourth embodiment, the arithmetic device 1002 functions as a higher-level external device and executes channel assignment processing for a plurality of wireless communication devices 2D.

  FIG. 14 is a block diagram illustrating a configuration example of one wireless communication device 2D and arithmetic device 1002 in FIG. In FIG. 14, the control unit 24D of the wireless communication apparatus 2D according to the fourth embodiment does not include the registration unit 25, the calculation unit 26, the determination unit 27, and the allocation unit 28 illustrated and described in the first embodiment. The registration unit 25, the calculation unit 26, the determination unit 27, and the allocation unit 28 are included in the arithmetic device 1002. The calculation means 26, the determination means 27, and the assignment means 28 constitute a main control means 1003. The main control unit 1003 includes a CPU, an external I / F, and the like.

  Note that the configurations and functions of the registration unit 25, the calculation unit 26, the determination unit 27, and the allocation unit 28 are the same as those of the first embodiment, and a description thereof will be omitted.

  The channel assignment processing executed by the arithmetic device 1002 only needs to execute the same processing as in Embodiments 1 to 3 described above using all channels as serial numbers, and thus detailed description thereof is omitted.

  As described above, according to the fourth embodiment of the present invention, when it is determined by the determination process that the communication load for the target channel satisfies the predetermined communication load condition, the assignment process performs at least two radios to be allocated to the channel. Since the same target channel is assigned to the communication device 2D, the number of channels assigned to the wireless communication device 2D can be made equal to or less than the number of channels in a specific frequency band. Thus, wireless communication with the wireless tag is performed. Is provided with a wireless communication system, a wireless communication method, and a program for causing the main control means 1003 to execute the processing steps of the wireless communication method in which both reduction of interference and improvement of communication efficiency are considered. It becomes possible.

  As a modification of the fourth embodiment, the notification unit 29 of the second embodiment is provided in the arithmetic device 1002, and the detection unit 30 and the instruction execution control unit 31 of the third embodiment are a plurality of wireless communication devices. It may be provided in the 2D control means 24D.

(Modification of the embodiment)
As a modification of each of the above embodiments, the wireless communication apparatus includes a noise measurement unit that measures communication noise for each channel, and the allocating unit 28 uses a measurement result obtained by the noise measurement unit (for example, carrier sense) and a predetermined value. The channel assignment process may be performed in consideration of the communication load condition. Thereby, the noise situation for each channel can be reflected in the channel assignment. In this case, a priority may be set in advance for each communication unit, and the assigning unit 28 may assign a channel with less noise measured by the noise measuring unit to a communication unit having a high priority. Thereby, the channel allocation which considered the noise condition for every channel and the priority for every communication part is realizable.

  In addition, as a modification of each of the above embodiments, the wireless communication device performs a wireless communication with the wireless tag 1 existing in the measurement region for each channel, thereby measuring a margin for measuring a margin of a radio wave transmission output. You may have a measurement means and the output adjustment means which adjusts a transmission output for every communication part according to the margin of the transmission output measured by this margin measurement means. As a result, for communication units with a large margin of transmission output, even if the transmission output is lowered, the transmission output is reduced by the output adjustment means within the range where access is sufficiently possible, so that the radio wave is transmitted to each communication unit. Interference can be optimally reduced.

  In this case, by performing wireless communication a plurality of times with the wireless tag 1 existing in the measurement region, the margin measuring means measures a plurality of margins of the transmission output, and a plurality of margins of the measured transmission output. You may calculate the average of. Thereby, the measurement accuracy of the margin of the transmission output can be improved, and further interference reduction can be achieved.

  In this case, the margin measuring unit may measure the access margin based on the number of times that the wireless tag 1 existing in the measurement area performs wireless communication a plurality of times and the wireless tag 1 is successfully accessed. As a result, for communication units with a large access margin, even if the transmission output is lowered, the transmission output is lowered by the output adjustment means within a range where access is sufficiently possible, so that radio wave interference is caused for each communication unit. It can be reduced optimally.

  As a modification of the fourth embodiment, the wireless communication system transmits a radio wave from the communication unit of one radio communication device, receives the radio wave from the communication unit of another radio communication device, and receives the received radio wave. And assigning means 28 corresponds to the calculated radio wave interference intensity according to the calculated radio wave interference intensity. Channel assignment may be performed. Thus, by assigning different channels to communication units having high radio wave interference strength, channel assignment can be performed in consideration of the radio wave interference strength.

  As a modification of each of the embodiments described above, in the wireless communication device, a plurality of communication units (for example, 21a and 21b) are arranged for one wireless tag (for example, 1a), and the communication unit 21a and the wireless tag are arranged. If the wireless communication with the wireless tag 1 fails and the wireless communication between the communication unit 21b and the wireless tag 1 is successful, the communication unit 21b may be used for wireless communication with the wireless tag 1a. Thereby, according to the magnitude | size of the workpiece | work to which the wireless tag 1a is attached, either of the some communication parts 21a and 21b can be selected automatically.

  As a modification of the first, second, and third embodiments, the wireless communication device knows information about channel assignment processing, registered command contents, and the like between the wireless communication devices. A synchronization I / F may be provided in order for the communication units assigned to the same channel to communicate with the wireless tag 1 at different timings in synchronization. In this case, the communication unit for the next process refers to the access result information of the communication unit for the previous process via the synchronous I / F, and the communication unit for the next process is the same as the communication unit for the previous process. By not performing wireless communication for the command, the burden of command setting by the user for each communication unit is reduced.

  In this case, the factory has a main production line and a sub-production line, and when the assembly of the module to be assembled to the main production line is performed on the sub-production line, it is arranged corresponding to the module completion process of the sub-production line. The control unit of the wireless communication apparatus reads the manufacturing information of the corresponding wireless tag in a lump, and the read manufacturing information of the wireless tag corresponds to the assembly initial process of the main manufacturing line via the synchronous I / F. It is also possible to transfer to the arranged wireless communication apparatus, and the control means of the wireless communication apparatus can collectively write the transferred wireless tag manufacturing information to the corresponding wireless tag. Thereby, the processing load by the external device can be reduced.

  As a modification of the third embodiment, when the control unit 24C determines that the contents of the instruction group registered in the registration unit 25 are the same between the communication units and only the address to be referred to is different, May be copied as it is, and the variable portion may be copied by incrementing the address.

  The wireless communication apparatus according to the present invention can be applied to a wireless tag reader / writer that reads information recorded on a wireless tag in a contactless manner. For example, as an individual object recognition system called a data carrier system or the like, a wireless tag is attached to an article to identify the article. Examples of this application include machine tool tools in the FA (Factory Automation) field, parts in factories, product management, article identification systems used in logistics systems, etc., railway ticket and supermarket price reading, and the like.

1 is a block diagram showing a configuration example of a wireless communication apparatus according to Embodiment 1 of the present invention. The block diagram which shows the example of 1 structure of the radio | wireless tag used in each embodiment of this invention The top view which shows one structural example of the wireless tag used in each embodiment of this invention The top view which shows one structural example of the communication part of the radio | wireless communication apparatus which concerns on each embodiment of this invention The flowchart which shows each process process of the channel allocation process by the control means of the radio | wireless communication apparatus which concerns on Embodiment 1 of this invention. Time chart showing channel assignment status assigned to meet communication load conditions FIG. 3 is a block diagram showing a configuration example of a wireless communication apparatus according to Embodiment 2 of the present invention. The flowchart which shows each process process of the channel allocation process by the control means of the radio | wireless communication apparatus which concerns on Embodiment 2 of this invention. Time chart showing channel assignment status when communication load conditions are not met Time chart showing channel assignment status when two thresholds for communication load conditions are provided FIG. 3 is a block diagram showing a configuration example of a wireless communication apparatus according to Embodiment 3 of the present invention. The flowchart which shows the process process in a specific communication part among the command execution processes by the control means of the radio | wireless communication apparatus which concerns on Embodiment 3 of this invention. Block diagram showing an example of the overall configuration of a wireless communication system according to a fourth embodiment of the present invention FIG. 13 is a block diagram showing a configuration example of one wireless communication device and arithmetic device in FIG.

Explanation of symbols

1, 1a, 1b,..., 1n wireless tags 2A, 2B, 2C, 2D wireless communication devices 21, 21a, 21b,..., 21n communication unit 22 switching means 23 transmission / reception circuits 24A, 24B, 24C, 24D control means 25 registration means 26 Calculation means 27 Judgment means 28 Assignment means 29 Notification means 30 Detection means 31 Instruction execution control means 1001a, 1001b, 1001c Production line 1002 Computing device 1003 Main control means

Claims (14)

A communication unit that transmits and receives communication data to and from a wireless tag using radio waves in a specific frequency band;
A wireless communication device having a controller unit to which a greater number of communication units than the number of channels allowed in the specific frequency band can be connected,
The controller unit is
Registration means for registering transmission data of the communication unit to the wireless tag in correspondence with each communication unit;
Based on the transmission data registered by the registration means, the amount of reception data received by the communication unit from the wireless tag is obtained, and communication for each communication unit is determined from the amount of transmission data and the amount of reception data. A calculation means for calculating a load;
Storage means for storing a communication load condition for setting a communication load assigned to each channel;
An allocating unit that allocates the channel to each communication unit based on the communication load for each communication unit calculated by the calculation unit so that the communication load for each channel satisfies the communication load stored in the storage unit. And
When the number of the communication units larger than the permitted number of channels is used, the allocating unit has two or more such that the communication load for each channel satisfies the communication load condition stored in the storage unit A radio communication apparatus characterized in that the same number of channels is allocated to the communication unit so that the number of channels allocated to the communication unit is less than or equal to the allowed number of channels.   The wireless communication apparatus according to claim 1, wherein the communication load is a total amount of communication data transmitted or received between the wireless tag and the communication unit or a communication required time.   The communication load condition is a condition in which a difference between a maximum communication load and a minimum communication load among communication loads for each channel is within a predetermined range. The wireless communication device described. The communication load condition is
When assigning a plurality of the communication units more than the plurality of channels to the plurality of channels equal to or less than the allowed number of channels by the assigning unit,
In all combinations of allocation of the plurality of channels and the plurality of communication units,
Find the maximum communication load among the communication loads for each channel in each of the combinations,
Among the maximum communication loads of each combination, a condition that extracts the combination with the minimum maximum communication load and assigns the plurality of communication units to the plurality of channels by the combination is a condition. The wireless communication apparatus according to claim 2. The controller unit further includes:
2. When assigning the channel for each communication unit by the assigning means, if the communication load condition is not satisfied, a notification means for notifying that the communication load condition is not satisfied is provided. The wireless communication device according to any one of claims 1 to 4.   6. The wireless communication apparatus according to claim 5, wherein the notification unit further notifies which channel the communication load condition is not satisfied.   6. The notification unit according to claim 5, wherein the notification unit notifies which of the transmission data of the communication unit, the communication load condition, and the number of the communication units to be used should be changed. The wireless communication device according to claim 6.   The wireless communication apparatus according to claim 1, wherein the specific frequency band is a UHF band. The controller unit further includes:
Detecting whether the wireless tag moving relative to the communication unit is present in a communicable region where the communication data can be transmitted and received with the communication unit or present in an impossible communication region Detection means;
When the detection unit detects that the wireless tag is present in the communicable area of the communication unit, the transmission of the transmission data to the wireless tag is started, and the transmission of the transmission data or the transmission data is started. If the detection means detects that the wireless tag has entered the non-communication area during the reception of the received data from the wireless tag, the transmission of the transmission data to the wireless tag is performed. Transmission control means for interrupting,
When transmission of the transmission data to the wireless tag is interrupted by the transmission control means, another wireless tag exists in the communicable area of the other communication unit assigned to the same channel as the communication unit If it is detected by the detection means, a start control means for starting transmission of the other transmission data from the other communication unit to the other wireless tag;
The wireless communication apparatus according to claim 1, further comprising: The transmission control means further includes:
The detection means detects that the wireless tag for which transmission of the transmission data has been interrupted has reentered the communicable area of the communication unit, and
Reception of reception data from the other wireless tag for the other transmission data started by the start control means is completed, or the other wireless tag has entered a communication impossible area of the other communication unit Is detected by the detection means,
The wireless communication apparatus according to claim 9, wherein transmission of the transmission data is resumed with respect to the communication unit in which transmission of the transmission data is interrupted. The transmission data registered in the registration means is a plurality of read commands or write commands for the wireless tag, or a command group including a combination of read commands and write commands,
The transmission control means further includes:
When resuming transmission of the transmission data to the communication unit where transmission of the transmission data has been interrupted, reception of reception data from the wireless tag has not been received in the command group of the transmission data. The wireless communication apparatus according to claim 10, wherein transmission is resumed from a completion command. A wireless communication device that transmits and receives communication data to and from a wireless tag using radio waves in a specific frequency band;
A wireless communication system having a computing device to which a greater number of the wireless communication devices than the number of channels allowed in the specific frequency band can be connected,
The arithmetic unit is
Registration means for registering transmission data of the wireless communication device to the wireless tag in correspondence with each wireless communication device;
Based on the transmission data registered by the registration means, an amount of reception data received by the wireless communication device from the wireless tag is obtained, and each wireless communication device is determined from the amount of transmission data and the amount of reception data. Calculating means for calculating the communication load of
Storage means for storing a communication load condition for setting a communication load assigned to each channel;
Based on the communication load for each wireless communication device calculated by the calculation means, the channel is assigned to each wireless communication device so that the communication load for each channel satisfies the communication load stored in the storage means. Allocation means,
When the number of the wireless communication devices larger than the allowed number of channels is used, the allocating unit has two or more so that the communication load for each channel satisfies the communication load condition stored in the storage unit A wireless communication system, wherein the same channel is assigned to the wireless communication device so that the number of channels assigned to the wireless communication device is less than or equal to the allowed number of channels. A communication unit that transmits and receives communication data to and from a wireless tag using radio waves in a specific frequency band;
A controller unit having a storage unit for storing a communication load condition for setting a communication load to be assigned to each channel, in which a larger number of the communication units than the number of channels allowed in the specific frequency band can be connected. When,
A wireless communication method used in a wireless communication device comprising:
A registration step of registering transmission data of the communication unit to the wireless tag in correspondence with each communication unit;
Based on the transmission data registered in the registration step, the amount of reception data received by the communication unit from the wireless tag is obtained, and the communication load for each communication unit is determined from the amount of transmission data and the amount of reception data. A calculation step of calculating
When a larger number of communication units than the allowed number of channels are used, the communication load for each channel is stored in the storage unit based on the communication load for each communication unit calculated by the calculation step. And assigning the same number of channels to two or more of the communication units so as to satisfy the communication load condition, so that the number of channels assigned to the communication unit is less than or equal to the allowed number of channels. A wireless communication method. A communication unit that transmits and receives communication data to and from a wireless tag using radio waves in a specific frequency band;
A controller unit having a storage unit for storing a communication load condition for setting a communication load to be assigned to each channel, in which a larger number of the communication units than the number of channels allowed in the specific frequency band can be connected. When,
A program for causing a computer mounted on the controller unit to execute processing in a wireless communication device comprising:
Registration processing for registering the transmission data of the communication unit to the wireless tag in correspondence with each communication unit;
From the transmission data registered by the registration process, the amount of reception data received by the communication unit from the wireless tag is obtained, and the communication load for each communication unit is determined from the amount of transmission data and the amount of reception data. A calculation process to calculate,
When the number of the communication units larger than the permitted number of channels is used, the communication load for each channel is stored in the controller unit based on the communication load for each communication unit calculated by the calculation process. Assigning the same number of channels to two or more of the communication units so as to satisfy a determined communication load condition, thereby reducing the number of channels assigned to the communication unit to be less than or equal to the allowed number of channels. A program characterized by being executed.

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