JPWO2007026412A1 - Communication station apparatus and communication method - Google Patents

Abstract

An interrupt permission time (interruption time) for interrupting communication is provided during the communication of the reader / writer device 100b (communication station device). The reader / writer devices 100a and 100c start transmission when detecting a free channel again after a predetermined waiting time has elapsed after detecting a free channel. Since the waiting time of the reader / writer device 100a having a high priority is shorter than the interruption time of the reader / writer device 100b, it is possible to interrupt and communicate. However, since the waiting time of the reader / writer device 100c having a low priority is longer than the interruption time of the reader / writer device 100b, it cannot be interrupted. Thereby, when reader / writer devices belonging to different systems are installed close to each other, it is possible to suppress reading of a tag due to the inability to acquire a communication channel while suppressing radio wave interference.

Description

  The present invention relates to a technique for suppressing mutual interference between communication station apparatuses.

There is a reader / writer device that communicates with a wireless tag (also referred to as an RFID (Radio Frequency Identifier), an IC tag, etc., hereinafter simply referred to as a “tag”).
Since the reader / writer device communicates by capturing weak radio waves emitted by the wireless tag, the reader / writer device is likely to be interfered by radio waves emitted by other reader / writer devices installed in the vicinity.
2. Description of the Related Art Conventionally, for example, there is a technique for preventing a plurality of reader / writer devices from interfering with each other by the method described in Patent Document 1.
The method described in Patent Document 1 is a detection unit that detects a signal wirelessly transmitted from another reader / writer device to a reader / writer device using an antenna for each communication channel, and idle communication that is in a no-signal state by the detection unit. By providing communication means for starting communication with the tag on the communication channel when the channel is detected, radio wave interference between the reader / writer devices is prevented.
JP 2000-242742 A JP-A-11-102419 JP 2003-283367 A JP 2000-268140 A Japanese Patent Laid-Open No. 10-124633 JP 2004-266550 A JP 2002-057608 A JP 11-149532 A Japanese Patent Laid-Open No. 11-003407 JP 2005-167706 A

  In the method described in Patent Document 1, when a plurality of reader / writer devices detect the same free communication channel, each reader / writer device does not have a priority order for acquiring the communication channel, and therefore, a communication channel can be acquired as necessary. It may not be possible. In addition, after acquiring the communication channel, the continuous communication time with the tag by the communication channel is not taken into consideration, so the communication channel is monopolized by a specific reader / writer device, and once communication channel acquisition fails, the communication channel is acquired for a while It may not be possible. From the above, for example, when a tag attached to a mobile body (mobile body tag) is passing through the reading area of the reader / writer device, there is a problem that a communication channel cannot be acquired and the tag may be read out. .

  The present invention has been made, for example, in order to solve the above-described problems, and each reader / writer device has a communication channel for communicating with a tag at a frequency and interval required for its use. The goal is to be able to earn.

The communication station apparatus according to the present invention is
In a communication station device that communicates with an information device,
A communication unit that communicates with the information device using the communication device;
A communication discriminating unit that discriminates whether or not another communication station device is communicating with the information device;
A communication time storage unit that stores a time for communicating with the information device using a storage device as a communication time;
An interruption time storage unit for storing the time for interrupting communication with the information device using the storage device as the interruption time;
Communication that causes the communication unit to interrupt communication with the information device when the communication time measured after the communication unit has started communication with the information device and the communication time stored in the communication time storage unit has elapsed An interruption part;
The communication interruption unit measures the elapsed time from the interruption of communication with the information device, and when the interruption time stored in the interruption time storage unit has elapsed, another communication station device is communicating with the information device. Otherwise, when the communication determination unit determines, a communication resumption unit that causes the communication unit to resume communication with the information device,
It is characterized by having.

The communication station apparatus according to the present invention further includes:
A priority storage unit that stores priority information indicating the priority of the communication station device using a storage device;
Based on the priority information stored in the priority storage unit, a communication time is calculated and stored in the communication time storage unit;
It is characterized by having.

The communication station apparatus according to the present invention further includes:
When the communication interruption unit interrupts communication with the information device, the communication interruption unit has an interruption information storage unit that stores information about the communication with which the communication unit communicated with the information device using a storage device,
The communication resuming unit restarts communication with the information device based on the information stored in the interruption information storage unit.

Moreover, the communication station apparatus according to the present invention further includes:
The communication time calculation unit
The communication time is calculated such that the higher the priority based on the priority information stored in the priority storage unit is, the longer the communication time is.

Moreover, the communication station apparatus according to the present invention further includes:
An interrupt request acquisition unit for acquiring an interrupt request for interrupting communication with the information device at a predetermined interval, notified to the communication station device by another communication station device;
Based on the interrupt request acquired by the interrupt request acquisition unit, a communication time is calculated and stored in the communication time storage unit;
It is characterized by having.

Moreover, the communication station apparatus according to the present invention further includes:
An interrupt request for interrupting communication with the information device at a predetermined interval, notified by the other communication station device to the communication station device, and interrupt interval information indicating a predetermined interval at which communication should be interrupted. An interrupt request acquisition unit for acquiring
When the interrupt request acquisition unit acquires an interrupt request, based on the interrupt interval information acquired by the interrupt request acquisition unit, a communication time is calculated and stored in the communication time storage unit;
It is characterized by having.

Moreover, the communication station apparatus according to the present invention further includes:
A priority storage unit that stores priority information indicating the priority of the communication station device using a storage device;
Priority information indicating the priority of the other communication station device, and an interrupt request for interrupting communication with the information device at a predetermined interval, notified to the communication station device by the other communication station device. An interrupt request acquisition unit for acquiring
When the interrupt request acquisition unit acquires an interrupt request, the priority based on the priority information acquired by the interrupt request acquisition unit is compared with the priority based on the priority information stored in the priority storage unit. A communication time calculation unit that calculates a communication time when the priority based on the priority information acquired by the interrupt request acquisition unit is higher, and stores the communication time in the communication time storage unit;
It is characterized by having.

Moreover, the communication station apparatus according to the present invention further includes:
An interrupt request notifying unit for notifying the other communication station apparatus of an interrupt request for requesting the other communication station apparatus to interrupt communication with the information apparatus at a predetermined interval is provided.

Moreover, the communication station apparatus according to the present invention further includes:
Interrupt request notification for notifying other communication station devices of an interrupt request for interrupting communication with an information device at a predetermined interval and interrupt interval information indicating a predetermined interval at which communication should be interrupted It has the part.

Moreover, the communication station apparatus according to the present invention further includes:
A priority storage unit that stores priority information indicating the priority of the communication station device using a storage device;
Interrupt request for notifying other communication station apparatus of interrupt request for interrupting communication with information apparatus at predetermined intervals, and priority information indicating the priority of the other communication station apparatus A notification unit;
It is characterized by having.

Moreover, the communication station apparatus according to the present invention further includes:
A priority storage unit that stores priority information indicating the priority of the communication station device using a storage device;
Based on the priority information stored in the priority storage unit, a waiting time calculating unit that calculates a waiting time until communication with the information device is started,
Measures the elapsed time since the communication determining unit determines that another communication station device is not communicating with the information device, and when the waiting time calculated by the waiting time calculating unit has elapsed, the other communication station A communication start unit that causes the communication unit to start communication with the information device when the communication determination unit determines that the device is not communicating with the information device;
It is characterized by having.

The communication station apparatus according to the present invention further includes:
The waiting time calculation unit
The waiting time is calculated such that the higher the priority based on the priority information stored in the priority storage unit, the shorter the waiting time.

Moreover, the communication station apparatus according to the present invention further includes:
Based on the priority information stored by the priority storage unit, an occupable time calculating unit that calculates an occupable time that can occupy communication with the information device;
Measures the elapsed time since the communication unit started communication with the information device, and terminates communication with the information device in the communication unit when the occupable time calculated by the occupancy time calculation unit has elapsed. A communication end unit to be
It is characterized by having.

The communication station apparatus according to the present invention further includes:
The occupable time calculation unit
The occupable time is calculated such that the higher the priority based on the priority information stored in the priority storage unit, the shorter the occupable time.

Moreover, the communication station apparatus according to the present invention further includes:
After the communication unit starts communication with the information device, if the communication determination unit determines that another communication station device is communicating with the information device, the communication unit stops communication with the information device. It has the communication cancellation part to be made.

A communication method according to the present invention includes:
In a communication method for communicating with an information device,
A communication start step in which the communication unit starts communication with the information device using the communication device;
In the communication start step, the communication interruption unit measures an elapsed time since the communication unit started communication with the information device, and the communication unit communicates with the information device when a predetermined communication time has elapsed. A communication interruption process for interrupting,
In the communication interruption step, the communication resumption unit measures the elapsed time since the communication unit interrupted communication with the information device, and when a predetermined interruption time has elapsed, the other communication station device communicates with the information device. An interrupt communication determination step in which the communication determination unit determines whether or not communication is performed; and
In the interrupt communication determining step, when the communication determining unit determines that another communication station device is not communicating with the information device, the communication resuming step in which the communication unit restarts communication with the information device,
It is characterized by having.

A communication station apparatus system according to the present invention includes:
In a communication station apparatus system comprising a plurality of communication station apparatuses communicating with an information apparatus,
At least one communication station device among the plurality of communication station devices is:
A communication unit that communicates with the information device using the communication device;
A communication discriminating unit that discriminates whether or not another communication station device is communicating with the information device;
Measures the elapsed time after the communication determining unit determines that another communication station device is not communicating with the information device, and the other communication station device communicates with the information device when a predetermined waiting time has elapsed. A communication start unit that causes the communication unit to start communication with the information device when the communication determination unit determines that it is not,
Have
At least one communication station device of the plurality of communication station devices is
A communication unit that communicates with the information device using the communication device;
A communication discriminating unit that discriminates whether or not another communication station device is communicating with the information device;
A communication time storage unit that stores a time for communicating with the information device using a storage device as a communication time;
An interruption time storage unit for storing the time for interrupting communication with the information device using the storage device as the interruption time;
Communication that causes the communication unit to interrupt communication with the information device when the communication time measured after the communication unit has started communication with the information device and the communication time stored in the communication time storage unit has elapsed An interruption part;
The communication interruption unit measures the elapsed time from the interruption of communication with the information device, and when the interruption time stored in the interruption time storage unit has elapsed, another communication station device is communicating with the information device. Otherwise, when the communication determination unit determines, a communication resumption unit that causes the communication unit to resume communication with the information device,
It is characterized by having.

  According to the present invention, for example, an interruption time for temporarily interrupting communication is provided for each predetermined communication time, communication is resumed if there is no interruption in the meantime, and if there is an interruption in between, the communication channel is handed over to each other. There is an effect that communication with the information apparatus can be performed without interference.

  According to the present invention, for example, since the communication time is calculated based on the priority of the communication station device, the communication time according to the priority of the communication station device can be obtained.

  According to the present invention, for example, information about communication when communication is interrupted is stored and used when communication is resumed. Therefore, the overhead due to communication interruption can be reduced.

  According to the present invention, for example, the communication time is calculated such that the higher the priority of the communication station device is, the longer the communication time is. Therefore, when the possibility of occurrence of interrupt communication is low, the number of times communication is interrupted is reduced. This reduces the overhead due to the interruption of communication.

  According to the present invention, for example, the communication time is calculated on the basis of an interrupt request notified by another communication station apparatus, so that an interruption time can be provided according to the necessity of interrupt communication.

  According to the present invention, for example, the communication time is calculated based on the interrupt interval information notified by the other communication station device, so that an interruption time can be provided in accordance with the interval where interrupt communication is necessary. Play.

  According to the present invention, for example, the communication time is calculated based on the interrupt request notified by the other communication station device only when the priority of the other communication station device is high. There is an effect that no interruption time is generated by an interrupt request from.

  According to the present invention, for example, an interrupt request is notified to another communication station apparatus, so that there is an effect that interrupt communication can be performed as necessary.

  According to the present invention, for example, the interrupt interval information is notified to another communication station apparatus, and therefore, there is an effect that interrupt communication can be performed in accordance with an interval that requires interrupt communication.

  According to the present invention, for example, the priority of the communication station apparatus is notified to another communication station apparatus, and therefore, the interrupt communication cannot be performed when the priority is lower than the other communication station apparatus. Play.

  According to the present invention, for example, after confirming that the communication channel is free, and after waiting time elapses, it is confirmed again whether the communication channel is free.

  According to the present invention, for example, the waiting time is calculated so that the waiting time becomes shorter as the priority of the communication station device becomes higher. Therefore, there is an effect that the communication station device having a higher priority can surely acquire the communication channel. .

  According to the present invention, for example, since communication exceeding the occupable time according to the priority of the communication station device is limited, it is possible to prevent the communication station device having a high priority from monopolizing the communication channel. Play.

  According to the present invention, for example, the occupable time is calculated such that the higher the priority of the communication station device is, the shorter the occupable time is. Therefore, the user of the communication station device appropriately sets the priority of the communication station device. There is an effect that it comes to set to.

  According to the present invention, for example, after the communication station apparatus starts communication, it is confirmed once again whether the communication channel is free, so that it is possible to detect a communication collision.

  According to the present invention, for example, an interruption time for temporarily interrupting communication is provided for each predetermined communication time, communication is resumed if there is no interruption in the meantime, and if there is an interruption in between, the communication channel is handed over to each other. There is an effect that communication with the information apparatus can be performed without interference.

  According to the present invention, for example, there is provided a communication station apparatus that provides an interruption time for temporarily interrupting communication every predetermined communication time, resumes communication if there is no interruption in between, and transfers a communication channel if there is an interruption in between The communication station device that detects that the communication channel is free due to the communication interruption and performs the interrupt communication operates in cooperation with each other, and it is possible to communicate with the information device without interfering with each other. .

Best mode for carrying out

Embodiment 1 FIG.
The first embodiment will be described with reference to FIGS.
FIG. 1 is a block configuration diagram showing an example of a block configuration of a reader / writer device 100 (an example of a communication station device) according to this embodiment.
FIG. 2 is a hardware configuration diagram illustrating an example of a hardware configuration of the reader / writer device 100 according to this embodiment.

  The reader / writer device 100 includes a transmission unit 110 (an example of a communication unit), a reception unit 120 (an example of a communication unit), a carrier sense unit 130 (an example of a communication determination unit), a control unit 140, a communication device 170, and a storage device 180. Have.

The transmission unit 110 modulates a command to the tag 300 (an example of an information device) and transmits it from the antenna 200 using the communication device 170.
The receiving unit 120 demodulates the response from the tag 300 received by the communication device 170 via the antenna 200.
The carrier sense unit 130 measures the power of the signal received by the communication apparatus 170 via the antenna 200 and senses (detects) the availability of the communication channel (hereinafter referred to as “carrier sense”).

The control unit 140 controls the entire reader / writer device 100. For example, the control unit 140 is realized by a CPU 190 (Central Processing Unit) executing a program stored in the storage device 180.
The control unit 140 includes a host PC (computer) control unit 141, a timer 142, and a transmission / reception control unit 150.
The host PC control unit 141 controls an interface with the host PC 400 using the interface device 191.
The timer 142 is a timer built in the reader / writer device 100, and measures time or time using a clock device 192.

  The transmission / reception control unit 150 controls the transmission unit 110, the reception unit 120, and the carrier sense unit 130. The transmission / reception control unit 150 includes a priority setting unit 151, a priority holding unit 152 (an example of a priority storage unit), a communication channel acquisition priority control unit 153 (an example of a waiting time calculation unit and a communication start unit), and an interrupt permission period generation. Unit 154 (an example of a communication interruption unit and an interruption time storage unit), an interrupt return unit 155 (an example of an interruption information storage unit and a communication resumption unit), a communication channel release unit 156 (an example of an occupable time calculation unit and a communication end unit) , Communication channel collision detection unit 157 (an example of communication cancellation unit), interrupt permission generation interval setting unit 158 (communication time calculation unit), interrupt permission generation interval request unit 159, interrupt permission generation interval holding unit 160 (communication time storage unit) Example).

The priority setting unit 151 provides a means for setting a priority in acquiring a communication channel.
The priority holding unit 152 (priority storage unit) holds (stores) the priority set by the priority setting unit 151 using the storage device 180.

  The communication channel acquisition priority control unit 153 (waiting time calculation unit, communication start unit) determines the communication channel in the carrier sense unit 130 within the carrier sense time (waiting time) corresponding to the priority held by the priority holding unit 152. Senses the availability, and if it is available, acquires the communication channel and starts transmission.

  The interrupt permission period generation unit 154 (communication interruption unit, interruption time storage unit) performs transmission at regular intervals (communication time) during inter-tag communication in the reader / writer device with low priority held in the priority holding unit 152. An interrupt permission period (interruption time) for interrupting the communication channel use right interrupt by the reader / writer device having a high priority is generated.

  The interrupt return unit 155 (interruption information storage unit, communication resumption unit) does not interrupt the communication channel usage right by the reader / writer device with high priority in the interrupt permission period (interruption time) generated by the interrupt permission period generation unit 154. In the event of a failure, communication between tags is resumed.

  The communication channel release unit 156 (occupiable time calculation unit, communication end unit) determines the continuous communication time (occupiable time) with the tag based on the priority held by the priority holding unit 152 and ends the continuous communication time. Then, the communication between the tags is terminated and the communication channel is released.

  The communication channel collision detection unit 157 (communication cancellation unit) senses the use status of the communication channel at the carrier sense unit 130 at the timing when the communication channel acquisition priority control unit 153 acquires the communication channel and starts inter-tag communication. If the communication channel is used by another reader / writer device, the transmission is stopped (stopped), and the communication channel acquisition control by the communication channel acquisition priority control unit 153 is performed again.

The interrupt permission generation interval setting unit 158 (communication time calculation unit) generates an interrupt permission period (interruption time) generated by the interrupt permission period generation unit 154 in the reader / writer device held by the priority holding unit 152 and having a low priority. A means for setting an interval (communication time) is provided.
The interrupt permission generation interval request unit 159 is an interrupt permission period generated by the interrupt permission period generation unit necessary for reliably reading the mobile tag in the reader / writer device having a high priority held by the priority holding unit 152. (Interruption time) is requested to the reader / writer device having a low priority held in the priority holding unit 152.
The interrupt permission generation interval holding unit 160 (communication time storage unit) uses the value of the interrupt permission generation interval (communication time) set by the interrupt permission generation interval setting unit 158 or the interrupt permission generation interval request unit 159 using the storage device 180. Hold (remember).

  In this embodiment, an operation when acquiring a communication channel for starting communication with a tag will be described.

  FIG. 3 is a diagram showing an example of a warehouse 800 that performs security management and inventory management using a plurality of reader / writer devices 100 (100a, 100b, 100c) according to this embodiment.

For example, the reader / writer device 100a constitutes a system for identifying and recording the employee 700 entering and leaving the warehouse 800 by communicating with the tag 300a attached to the employee card via the antenna 200a.
On the other hand, the reader / writer devices 100b and 100c manage the items, quantities, and the like of the inventory 810 in the warehouse 800 by communicating with the tag 300b attached to the inventory 810 via the antennas 200b and 200c, respectively. The system is configured.

  The communicable ranges of the antennas 200a, 200b, and 200c with respect to the tag 300 (300a and 300b) are arranged so as not to overlap each other.

  However, since the signal transmitted from the antenna 200 (200a, 200b, 200c) to the tag 300 is very strong compared to the signal transmitted from the tag 300 to the antenna 200, the antenna 200 transmits to the tag 300. It is conceivable that the other antenna 200 arranged outside the communicable range of the antenna 200 receives the received signal and interferes with the communication with the tag 300.

  Further, when the communicable ranges of the antennas 200a, 200b, and 200c with respect to the tag 300 overlap each other, the tag 300 receives signals transmitted from the plurality of antennas 200 at the same time, and neither of them can receive correctly. Can be considered.

  Therefore, while one reader / writer device 100 is performing transmission / reception, it is necessary to perform control so that the other reader / writer device 100 does not perform transmission.

  At this time, when a plurality of reader / writer devices constitute one system, such as the reader / writer devices 100b and 100c, for example, the host PC 400 to which the reader / writer devices 100b and 100c are commonly connected. It is relatively easy to adjust the transmission timings based on the control signals from.

  However, when another system is configured like the reader / writer device 100a, there is no host PC 400 to which a plurality of reader / writer devices 100 are connected in common, so it is difficult to adjust the transmission timing with each other.

  In addition, in the case of a single office, it is possible to mutually adjust the transmission timing by integrating the systems. However, each reader / writer at a plurality of adjacent stores or the like by different companies. If a system using the device 100 is used, the system cannot be integrated.

  In this embodiment, even in such a case, the transmission timings of the plurality of reader / writer devices 100 can be adjusted to each other.

  In this embodiment, when a plurality of reader / writer devices want to transmit simultaneously, channel acquisition priority is assigned to the reader / writer device, and control is performed so that a reader / writer device with a high priority can easily acquire a channel. .

  Hereinafter, operations when channel acquisition priorities are different among a plurality of reader / writer apparatuses 100 within a range where they are subject to interference with each other will be described.

FIG. 4 is a diagram illustrating an example in the case where communication priorities in a plurality of reader / writer devices 100 are different in this embodiment.
For example, when the reader / writer device 100 (100a in FIG. 2) that communicates with the mobile tag (300a in FIG. 3) cannot communicate with the tag 300 for a long time, the tag 300 is connected to the antenna 200 ( It passes through the communicable range of the antenna 200a) in FIG. Therefore, such a reader / writer device 100 needs to frequently communicate with the tag 300 at intervals shorter than a predetermined interval. Therefore, such a reader / writer device 100 sets a high priority.
On the contrary, the reader / writer device 100 (100b, 100c in FIG. 3) that communicates with the static tag (300b in FIG. 3; means that the tag 300 moves relatively little) has a period during which the tag 300 cannot communicate. However, there are few concerns about overwriting. Therefore, such a reader / writer device 100 sets a low priority.

  In addition, for example, in the case of a system that performs security-related processing, reading over is absolutely not allowed, so it is conceivable to set a high priority.

  FIG. 4 briefly summarizes an example of operation contents of the reader / writer device 100 having different priorities in this embodiment.

  In this embodiment, in particular, an operation (communication start process) until the reader / writer device 100 in the communication waiting state starts communication will be described.

FIG. 5 shows an operation flow until the reader / writer device 100a having a high channel acquisition priority starts communication with the tag 300 when the two reader / writer devices 100a and 100b are in a communication waiting state in this embodiment. It is a timing diagram which shows an example.
In FIG. 5, the two reader / writer devices 100a and 100b detect the empty channel and then perform carrier sense, and the reader / writer device 100a with the higher channel acquisition priority acquires the communication channel and starts communication.
FIG. 6 is a flowchart showing an example of the operation flow of the reader / writer device 100a having a high channel acquisition priority during the operation of FIG.
FIG. 7 is a flowchart showing an example of the operation flow of the reader / writer device 100b having a low channel acquisition priority during the operation of FIG.

  First, a processing flow in the reader / writer device 100a having a high channel acquisition priority will be described with reference to FIGS.

In the channel acquisition priority setting step (S11), the channel acquisition priority (priority) is set.
In S11, the priority setting unit 151 sets the channel acquisition priority of the reader / writer device 100a. The priority holding unit 152 stores the channel acquisition priority value (priority information) set by the priority setting unit 151 using the storage device 180.
The setting of the channel acquisition priority in the priority setting unit 151 is performed, for example, by allowing the system user to input a numerical value indicating the priority using a keyboard 193 (an example of an input device).
Alternatively, from the display on the LCD 194 (Liquid Crystal Display: an example of a display device), the use of the reader / writer device 100a (whether it is communication with a mobile tag or security relationship) is selected by the system user The priority value corresponding to the usage selected by the user may be set.
In this case, it is preferable that the relationship between the usage and the standard value of the priority value corresponding thereto is standardized and determined in advance because the priority level is determined between reader / writer devices of different manufacturers.

  The channel acquisition priority setting step (S11) is an initial setting performed when the reader / writer device 100a is installed or when it is found that interference with another reader / writer device 100b or the like has occurred. Steps S12 and after are operations when the communication with the tag 300 is actually performed.

In the free channel detection step (S12, S13), the reader / writer device 100a detects a free channel (a communication channel not in use).
In S12, the carrier sense unit 130 of the reader / writer device 100a starts carrier sense for the communication channel.
As a specific method of the carrier sense, for example, the power of the signal received by the antenna 200a is measured for the frequency of the communication channel used by the reader / writer device 100a. The carrier sense unit 130 determines that the communication channel is in use when the measured power is larger than a predetermined threshold value set in advance.

  Normally, the reader / writer device 100 continues to radiate radio waves of the frequency of the communication channel during the period of communication with the tag 300 in order to supply power to the tag 300. Therefore, if the signal of the frequency of the communication channel is received and the power is measured, it is possible to determine whether another reader / writer device 100 is communicating with the tag 300.

  Note that the frequency of the radio wave for power supply may be different from the frequency of the radio wave for communication. In that case, if the signal transmitted by the tag 300 can be detected by setting the threshold value small, it can be determined whether or not the communication channel is in use.

  In addition, when there are a plurality of communication channels used for communication with the tag 300, carrier sense is performed for each communication channel.

  In the example of FIG. 5, while the reader / writer device 100c is communicating with the tag 300, both the reader / writer devices 100a and 100b receive the radio wave transmitted by the reader / writer device 100c and the communication channel is in use. Determine that there is.

  In S13, the carrier sense unit 130 of the reader / writer device 100a determines whether an empty channel has been detected. If an empty channel cannot be detected, the process returns to S12 and carrier sensing is continued. If even one empty channel is detected, the process proceeds to the next step (S14).

  In the example of FIG. 5, the reader / writer device 100 c ends communication with the tag 300 and stops transmitting radio waves. The reader / writer devices 100a and 100b determine that the communication channel is free when the carrier sense unit 130 no longer detects radio waves.

In the carrier sense step (S14, S15), the reader / writer device 100a performs carrier sense during the high priority carrier sense period.
In S14, the communication channel acquisition priority control unit 153 of the reader / writer device 100a performs carrier sense at a time determined randomly within the carrier sense period for high priority for the communication channel detected by the carrier sense unit 130 in S13. To implement.
That is, the communication channel acquisition priority control unit 153 calculates the waiting time until the second carrier sense is performed based on the priority information stored in the priority holding unit 152.
At this time, a value is calculated such that the higher the priority, the shorter the waiting time.

In this example, it is assumed that there are two types of priority, “high” and “low”. The high priority waiting time may be a value shorter than the low priority waiting time.
Furthermore, since there are only two types of priorities, the waiting time is not set to a constant value but is set to a randomly determined value within a certain range in preparation for the case where the reader / writer device 100 having the same priority exists. Yes. As a result, when the priorities are the same, it is determined at random which one acquires the transmission right.

When there are more types of priorities, for example, the waiting time may be obtained by multiplying the value indicating the priority (the smaller the priority is, the higher the priority is) by the unit time.
Also, if there are many types of priorities, the possibility that the reader / writer devices 100 of the same priority will interfere with each other becomes low. Therefore, it is possible to calculate a certain waiting time without adding random elements to the waiting time. Good.

Also, if the range that randomly determines the waiting time is set so that it does not overlap with the waiting time range of different priorities, the one with the higher priority always acquires the transmission right before the one with the lower priority Thus, only when the priorities are equal, the reader / writer device 100 that acquires the transmission right is determined stochastically.
On the other hand, if the range that randomly determines the waiting time is set to overlap with the waiting time range of different priorities, basically, those with higher priority can easily acquire the transmission right. This means that the lower one may acquire the transmission right.

Using the timer 142, the communication channel acquisition priority control unit 153 measures the elapsed time after the carrier sense unit 130 detects a free channel and compares it with the calculated waiting time.
To do.
Then, when the communication channel acquisition priority control unit 153 determines that the elapsed time after the carrier sense unit 130 detects an empty channel has become longer than the waiting time, the carrier sense unit 130 again uses the same communication channel. Carrier sense is performed to determine whether the communication channel is in use.

  In addition, it is good also as not performing carrier sense at the time when waiting time passed, but performing carrier sense continuously during waiting time. In that case, when the communication channel is in use, it can be determined that the communication channel is in use without waiting for the waiting time to elapse.

In S15, the communication channel acquisition priority control unit 153 determines whether the communication channel that was an empty channel in S13 is an empty channel even as a result of the carrier sense in S14.
If all of the communication channels that were vacant channels in S13 are in use instead of vacant channels as a result of the carrier sense in S14, the process returns to S12 and carrier sense is continued for all communication channels again. .
If at least one communication channel that is a vacant channel is found in the carrier sense of S14 among the communication channels that were vacant in S13, the process proceeds to the next step (S16).

In the example of FIG. 5, since the reader / writer device 100a has a higher priority than the reader / writer device 100b, the waiting time of the reader / writer device 100a (the carrier sense period for higher channel acquisition priority) is higher. Is shorter than the waiting time (carrier sense period for low channel acquisition priority). Therefore, when the waiting time of the reader / writer device 100a has elapsed, the waiting time of the reader / writer device 100b has not yet elapsed. Therefore, neither the reader / writer device 100a or 100b starts transmission to the tag 300.
Therefore, the communication channel acquisition priority control unit 153 of the reader / writer device 100a determines that the communication channel that was an empty channel in S13 is still an empty channel, and proceeds to the next step (S16).

In the communication channel acquisition step (S16), the reader / writer device 100a acquires a communication channel.
In S16, the communication channel acquisition priority control unit 153 of the reader / writer device 100a uses the empty channel detected by the communication channel acquisition priority control unit 153 in S15, and the transmission unit 110 starts communication with the tag 300.
That is, in order for the reader / writer device 100a to communicate with the tag 300, it is necessary to supply power to the tag 300. Therefore, the transmission unit 110 of the reader / writer device 100a transmits a radio wave for supplying power using the frequency of the communication channel to be used.

  Thus, the reader / writer device 100a acquires the transmission right and can communicate with the tag 300.

  Next, a processing flow in the reader / writer device 100b having a low channel acquisition priority will be described with reference to FIGS.

In the channel acquisition priority setting step (S11), the channel acquisition priority is set.
The operation of the reader / writer device 100b in the channel acquisition priority setting step is the same as the operation of the reader / writer device 100a in the channel acquisition priority setting step described with reference to FIG.

In the free channel detection step (S12, S13), the reader / writer device 100b detects a free channel (a communication channel that is not in use).
The operation of the reader / writer apparatus 100b in the empty channel detection step is the same as the operation of the reader / writer apparatus 100a in the empty channel detection step described with reference to FIG.

In the carrier sense step (S14, S15, S24, S25), the reader / writer device 100b executes carrier sense in the carrier sense period for low priority.
In S14, the communication channel acquisition priority control unit 153 of the reader / writer device 100a performs carrier sense on the communication channel detected by the carrier sense unit 130 in S13 at the time when the high-priority carrier sense period expires. .

In this embodiment, the waiting time when the priority is different is set so that there is no overlap in the randomly determined range, so that the waiting time calculated by the communication channel acquisition priority control unit 153 of the reader / writer device 100b with low priority is calculated. The time is always longer than the waiting time calculated by the communication channel acquisition priority control unit 153 of the reader / writer device 100a having a high priority.
Therefore, the carrier sense unit 130 of the reader / writer device 100b with a low priority performs carrier sense before the waiting time calculated by the communication channel acquisition priority control unit 153 elapses.
In particular, if carrier sense is performed at the time when the high-priority carrier sense period expires, when the reader / writer device 100a having higher priority than the reader / writer device 100b starts transmission, the communication channel is used at that time. Since it can be detected that there is no waiting time, there is no need to wait until the waiting time has elapsed.

In S15, the communication channel acquisition priority control unit 153 determines whether the communication channel that was an empty channel in S13 is an empty channel even as a result of the carrier sense in S14.
If all of the communication channels that were vacant channels in S13 are in use instead of vacant channels as a result of the carrier sense in S14, the process returns to S12 and carrier sense is continued for all communication channels again. .
If at least one communication channel that is a vacant channel is found in the carrier sense of S14 among the communication channels that were vacant in S13, the process proceeds to the next step (S24).

  In S24, the communication channel acquisition priority control unit 153 of the reader / writer device 100a determines the communication channel determined to be an empty channel continuously in S15 at a time determined randomly within the low-priority carrier sense period. , Carry out career sense.

In S25, the communication channel acquisition priority control unit 153 determines whether or not the communication channel that was an empty channel in S15 is an empty channel even as a result of the carrier sense in S24.
If all of the communication channels that were vacant channels in S15 are in use instead of vacant channels as a result of the carrier sense in S24, return to S12 and continue carrier sense for all communication channels again. .
If at least one communication channel that is a vacant channel is found in the carrier sense of S24 among the communication channels that were vacant in S15, the process proceeds to the next step (S16).

Note that S13 and S14 may be omitted, and carrier sense may be performed only once after the waiting time has elapsed.
Or it is good also as continuing a carrier sense until waiting time passes.
In this case, even if the priorities are different, the processing flow does not change, so that the control is simple and preferable.

In the example of FIG. 5, when the reader / writer device 100c stops transmission and a communication channel becomes available, the carrier sense unit 130 of the reader / writer device 100b detects an available channel.
In the communication channel acquisition priority control unit 153, after the channel acquisition priority low carrier sense period (waiting time) elapses, the carrier sense unit 130 performs carrier sense again.
However, since the reader / writer device 100a having a higher priority than the reader / writer device 100b started communication using the channel before that, the carrier sense unit 130 of the reader / writer device 100b is using the communication channel. It is determined that
Therefore, the reader / writer device 100b fails to acquire a channel, returns to S12, and continues carrier sense.

On the other hand, when the reader / writer device 100a stops transmission and the communication channel is free, the carrier sense unit 130 of the reader / writer device 100b detects the free channel.
In the communication channel acquisition priority control unit 153, after the channel acquisition priority low carrier sense period (waiting time) elapses, the carrier sense unit 130 performs carrier sense again.
Since there is no other reader / writer device waiting for communication this time, the carrier sense unit 130 of the reader / writer device 100b detects that the communication channel is free even in the second carrier sense. Accordingly, the process proceeds to the next step (S16).

In the communication channel acquisition step (S16), the reader / writer device 100b acquires a communication channel.
In S16, the communication channel acquisition priority control unit 153 of the reader / writer device 100b uses the empty channel detected by the communication channel acquisition priority control unit 153 in S25, and the transmission unit 110 starts communication with the tag 300.
That is, in order for the reader / writer device 100a to communicate with the tag 300, it is necessary to supply power to the tag 300. Therefore, the transmission unit 110 of the reader / writer device 100a transmits a radio wave for supplying power using the frequency of the communication channel to be used.

  In the example of FIG. 5, after the reader / writer device 100b succeeds in acquiring a channel, the transmission unit 110 starts transmission.

  As described above, different carrier sense times (waiting times) are given depending on channel acquisition priorities, and the carrier sense time of a reader / writer device with a high priority is shorter than the carrier sense time of a reader / writer device with a low priority. By doing so, there is an effect that the reader / writer device with high priority can easily acquire the communication channel.

Embodiment 2. FIG.
The second embodiment will be described with reference to FIGS.
Since the functional block configuration of the reader / writer device 100 (an example of a communication station device) in this embodiment is the same as that described with reference to FIG. 1 in the first embodiment, description thereof is omitted here.

  In this embodiment, an operation in a case where an interrupt by a reader / writer device having a channel acquisition priority higher than that of itself is permitted during communication with the tag 300 will be described.

FIG. 8 is a timing chart showing an example of the flow of an operation for generating an interrupt permission period at regular intervals when the reader / writer device 100b having a low channel acquisition priority is communicating with the tag 300 in this embodiment. FIG.
FIG. 9 is a flowchart showing an example of the operation flow of the reader / writer device 100b having a low channel acquisition priority during the operation of FIG.

In the interrupt permission generation interval setting step (S31, S32), an interrupt permission generation interval (communication time) that is an interval for generating an interrupt permission period is set in the reader / writer device 100b.
In S31, the interrupt permission generation interval setting unit 158 (communication time calculation unit) of the reader / writer device 100b sets the value of the interrupt permission generation interval.
For example, the user of the system is caused to input the value of the interrupt permission generation interval using an input device.
Alternatively, the interrupt permission generation interval may be calculated based on the priority information stored in the priority holding unit 152 (priority storage unit).
In that case, the interrupt permission generation interval (communication time) may be made longer as the priority is higher. Since the reader / writer device 100 with high priority has many opportunities to acquire a communication channel, the number of tags 300 that must be communicated in one communication is small, and therefore the time required for one communication is short. Therefore, since it is unlikely that an interrupt needs to be permitted, the interrupt permission generation interval may be long. Also, if the priority is high, the reader / writer device 100 having a higher priority than itself is few, so that there are few scenes that require interruption. Therefore, it is not necessary to permit interrupt frequently, and the interrupt permission generation interval may be long.
On the other hand, since the reader / writer device 100 with low priority has few opportunities to acquire a communication channel, the number of tags 300 that must be communicated in one communication may increase. Then, since the time required for one communication becomes longer, there is a high possibility that the reader / writer device 100 having a high priority needs to communicate with the tag 300 during that time. Therefore, it is necessary to shorten the interrupt permission generation interval.

  Accordingly, when there is a high possibility of receiving an interrupt from another reader / writer device, more interrupt permission periods are generated, which is preferable because communication need not be interrupted wastefully.

Further, in the case of the reader / writer device 100a that performs communication with the mobile tag, the mobile tag may pass through the communicable area while the interruption is permitted, and there is a possibility that reading over may occur. Therefore, it is not preferable to permit interrupts too frequently. Therefore, when the priority of the reader / writer device 100a that communicates with the mobile tag is set high, it is preferable that the interrupt permission generation interval is long.
On the other hand, in the case of the reader / writer devices 100b and 100c that perform communication with the static tag, there is little fear that the static tag will disappear from the communicable area while the interrupt is permitted, and reading may occur. There is not much sex. Therefore, interrupts may be permitted frequently. Therefore, when the priority of the reader / writer devices 100b and 100c that communicate with the static tag is set to be low, it is preferable that the interrupt permission generation interval is short.

  In S <b> 32, the interrupt permission generation interval holding unit 160 (communication time storage unit) stores the value of the interrupt permission generation interval set by the interrupt permission generation interval setting unit 158 using the storage device 180.

  Note that the interrupt permission generation interval setting step (S31, S32) may be performed as an initial setting when the reader / writer device 100 is installed or when it is found that the reader / writer device 100 is interfering with another reader / writer device 100. Or it is good also as calculating every time of communication with a tag.

In the inter-tag communication start step (S33), the reader / writer device 100b starts communication with the tag 300.
In the reader / writer device 100b, the communication channel acquisition priority control unit 153 (waiting time calculation unit, communication start unit) of the transmission / reception control unit 150 acquires a free communication channel by the operation described in the first embodiment, for example. The transmission unit 110 and the reception unit 120 (communication unit) start communication with the tag 300 using the acquired communication channel.
Further, the interrupt permission period generation unit 154 (communication interruption unit, interruption time storage unit) starts a timer 142 built in the reader / writer device 100b and measures the time during which the reader / writer device 100b is communicating with the tag 300.

  In the interrupt permission period generation step (S34 to S36), the reader / writer device 100b generates an interrupt permission period (interruption time) during communication with the tag 300.

  In S <b> 34, the timer 142 built in the reader / writer device 100 measures the elapsed time during which the reader / writer device 100 b communicates with the tag 300. The interrupt permission period generation unit 154 sets the interrupt permission generation interval (communication time) set by the interrupt permission generation interval setting unit 158 and held by the interrupt permission generation interval holding unit 160 in S31 and the elapsed time measured by the timer 142. Compare. If it is detected that the elapsed time has reached the interrupt permission generation interval, the process proceeds to the next step (S35).

In S <b> 35, the interrupt return unit 155 (interruption information storage unit, communication resumption unit) stores information regarding communication with the tag 300 being executed using the storage device 180.
Examples of the information related to communication with the tag 300 include a communication protocol and read tag ID (Identifier) information. That is, when there are a large number of tags 300 responding to the ID notification command from the reader / writer device 100 to the tags 300, it may not be possible to communicate with all the responding tags 300 within the interrupt permission generation interval. In that case, by storing the ID of the already communicated tag 300, it is possible to identify which of the uncommitted tags 300 after the communication is resumed. Or you may memorize | store ID of the tag which has not communicated.
The transmission unit 110 of the reader / writer device 100b stops the emission of power supply radio waves to the tag 300, and interrupts communication with the tag 300.
As a result, the tag 300 cannot receive power and stops communication with the reader / writer device 100b.
Further, the other reader / writer device 100a can determine that the communication on this communication channel is interrupted by detecting that the radio wave for power supply is not received.

  In the example of FIG. 8, the reader / writer device 100b measures the elapsed time after starting or resuming communication with the tag 300, and communicates with the tag when the interrupt permission generation interval (communication time) is reached. Interrupt.

In S36, the carrier sense unit 130 (communication determination unit) of the reader / writer device 100b performs carrier sense of the communication channel used and determines whether there is another reader / writer device that performs interrupt communication.
The interrupt permission period generation unit 154 performs carrier sense by the carrier sense unit 130 only for a time (interruption time) sufficient for another reader / writer device to start interrupt communication.

  The interrupt permission period generation unit 154 calculates the interruption time in advance and stores it using the storage device 180.

  Note that the carrier sense may not be performed continuously, but may be performed after the interruption time ends.

The sufficient time for another reader / writer device to start interrupt communication is, for example, the carrier sense time for high priority in the first embodiment.
Other reader / writer devices detect that the communication channel has been released by the carrier sense unit 130 performing carrier sense, but at that time, it is not possible to determine whether the communication has ended or has just been interrupted.
Therefore, the other reader / writer devices do not realize that they perform interrupt communication, and perform the same operation as the start of normal communication.

For example, in the case of a reader / writer device that performs the operation at the start of communication described in the first embodiment, after a predetermined waiting time elapses after the communication channel acquisition priority control unit 153 detects that a communication channel is free. The communication channel acquisition process is performed.
At this time, if the reader / writer device has a high priority, the waiting time is the carrier sense time for high priority. In the case of a reader / writer device with a low priority, the waiting time is a carrier sense time for low priority.
Therefore, if an interruption time for interruption is provided only for the high-priority carrier sense time, if a high-priority reader / writer device is waiting for communication, communication is started before that time elapses. Therefore, interrupt communication is possible.
On the other hand, the low-priority reader / writer device waits until the low-priority carrier sense time (longer than the high-priority carrier sense time) elapses. It is not interrupted by a low reader / writer device.

  In the example of FIG. 8, the reader / writer device 100a having a high channel acquisition priority can acquire a communication channel by interrupting within the interruption time, but the reader / writer device 100c having a low channel acquisition priority interrupts within the interruption time. Can not acquire the communication channel.

When there are more types of priorities, the priority setting unit 151 of the reader / writer device 100b sets, and the waiting is calculated by the communication channel acquisition priority control unit 153 based on the priority information held by the priority holding unit 152 If the interruption time is provided for the same time as the time, the reader / writer device having higher priority than the reader / writer device 100b is allowed to interrupt, and the reader / writer device having lower priority than the reader / writer device 100b is not interrupted. Can do.
Alternatively, by setting the interruption time in relation to the waiting time calculated by the communication channel acquisition priority control unit 153, an interrupt by the reader / writer device that has a higher priority than the reader / writer device 100b but does not have a large difference in priority. It is also possible not to allow this, or it is possible to permit an interrupt only to a reader / writer device having a higher priority than a certain value.
That is, the reader / writer devices that perform the operation at the start of communication described in the first embodiment can freely set the relationship between priority and interrupt permission.

  In the interrupt status confirmation step (S37 to S38), the reader / writer device 100b confirms the interrupt status.

In S37, the timer 142 of the reader / writer device 100b measures the elapsed time since the communication with the tag 300 was interrupted.
The interrupt permission period generation unit 154 determines whether the interruption time measured by the timer 142 has reached, for example, the carrier sense time for high priority, and proceeds to the next step (S38).

  In S38, the interrupt permission period generation unit 154 determines whether communication by another reader / writer device is detected as a result of the carrier sense by the carrier sense unit 130. If not detected (no interrupt), the process proceeds to S39. . If communication by another reader / writer device is detected (interrupt occurs), the process proceeds to S40.

  If communication by another reader / writer device is detected before the interruption time elapses, the process may proceed to S40 without waiting for the interruption time to elapse.

  In the inter-tag communication resuming step (S39), the reader / writer device 100b resumes communication with the tag 300.

In S39, the interrupt return unit 155 of the reader / writer device 100b uses the communication channel (the channel that was originally used for communication with the tag 300) in which communication by another reader / writer device was not detected in S38. The communication with the tag 300 is resumed based on the information related to the communication with the tag 300 stored using the storage device in S35.
For example, if the ID of the already communicated tag 300 is stored, after the communication is resumed, an ID notification command is transmitted to the tag 300, and only the response from the uncommitted tag 300 among the responses from the tag 300 Can be selected, and based on this, only the uncommitted tag 300 can communicate.
Or it is good also as transmitting ID notification instruction | command after transmitting the instruction | indication not to respond with respect to the tag 300 with which communication was completed. Then, only the non-communication tag 300 responds to the ID notification command. Therefore, if communication is performed with the responding tag 300, communication is automatically performed only with the non-communication tag 300.
Alternatively, when the ID of the non-communication tag 300 is stored, the ID notification command may not be transmitted, and communication with the tag 300 may be resumed based on the stored ID. By doing so, overhead due to communication interruption can be reduced.

  In addition, when communication is resumed, the communication channel originally communicated with the tag 300 is used, and the communication protocol and the like stored in S35 are used. Therefore, it is not necessary to reset the communication setting of the tag 300, and communication is interrupted. Overhead can be reduced.

  If the communication continues after the communication is resumed, the process returns to S34 to periodically generate an interrupt permission period.

In the communication channel release step (S40), the reader / writer device 100b releases the communication channel.
That is, since the communication channel originally used cannot be used due to an interruption of another reader / writer device, the communication resumption by the communication channel is abandoned. Then, in order to newly start communication with the tag 300, another communication channel that can be used is searched and acquired.

In S40, the carrier sense unit 130 of the reader / writer device 100b starts carrier sense for another communication channel. When a free channel is detected, the communication channel acquisition priority control unit 153 acquires a communication channel.
The acquisition of the communication channel is performed by the operation described in the first embodiment, for example.
Since there is a possibility that interrupt communication by another reader / writer device is terminated before acquiring another communication channel, carrier sense may be similarly performed for the communication channel originally used.
Further, the communication resuming operation after acquiring a new communication channel may be the same as that at the start of normal communication. Alternatively, communication may be resumed based on the information stored by the interrupt return unit 155 using the storage device 180 in S35. Or it is good also as restarting communication based on the information which the interruption return part 155 memorize | stored using the memory | storage device 180, only when it measured after the time taken to restart and it was able to restart without leaving an interval.

In the example of FIG. 8, after the transmission is interrupted, the sense of the same communication channel is carrier sensed after the interruption permission period (interruption time) has elapsed.
When the transmission is interrupted for the first time, no transmission has occurred and transmission is resumed.
When the transmission is interrupted for the second time, an interrupt has occurred. Therefore, the communication channel is handed over, another empty channel is obtained, and a transmission waiting state is entered.

  As described above, while the reader / writer device 100b having a low channel acquisition priority is communicating with the tag 300, the communication is interrupted at regular intervals, and another reader / writer device having a high priority has the right to use the communication channel. And a period for permitting interrupt communication can be provided to prevent the communication channel from being monopolized by a low-priority reader / writer device. In addition, it becomes possible for a reader / writer device with high priority to easily acquire a communication channel.

  Furthermore, by setting an interruption time for permitting an interrupt, an interrupt by a reader / writer device having a low priority can be prevented, and the priority range of the reader / writer device permitting an interrupt can be changed.

  In addition, by storing the communication state before the communication interruption, the communication can be resumed with a fewer procedure than when the normal communication is started, so that the overhead due to the communication interruption can be minimized.

Embodiment 3 FIG.
The third embodiment will be described with reference to FIG.
Since the functional block configuration of the reader / writer device 100 (an example of a communication station device) in this embodiment is the same as that described with reference to FIG. 1 in the first embodiment, description thereof is omitted here.

In this embodiment, an operation for preventing the reader / writer device 100 having a high priority from occupying a communication channel will be described.
According to the configuration of the first embodiment or the second embodiment, the reader / writer device 100 having a high priority can preferentially acquire a communication channel. Therefore, if the reader / writer device 100 with high priority continues to occupy the communication channel, the reader / writer device with low priority cannot acquire the communication channel and may not be able to communicate with the tag 300.

  Therefore, the reader / writer apparatus according to this embodiment operates so that the reader / writer apparatus 100 having a high priority does not continue to occupy the communication channel.

  FIG. 10 is a flowchart showing an example of the operation flow of the reader / writer device 100a having a high channel acquisition priority according to this embodiment.

In the inter-tag communication start step (S41), the reader / writer device 100a starts communication with the tag 300.
In S41, the reader / writer device 100a acquires a communication channel free by the communication channel acquisition priority control unit 153 (waiting time calculation unit, communication start unit) of the transmission / reception control unit 150, for example, by the operation described in the first embodiment. Then, the transmission unit 110 and the reception unit 120 start communication with the tag 300.
At the same time, the communication channel release unit 156 (occupiable time calculation unit, communication end unit) starts measuring the elapsed time of communication with the tag 300 using the timer 142 built in the reader / writer device 100. .

  In the inter-tag communication time confirmation step (S42 to S43), the elapsed time during which the reader / writer device 100a communicates with the tag 300 is confirmed.

In S42, the communication channel releasing unit 156 of the reader / writer device 100a calculates the continuous communication time (occupiable time) recognized by the reader / writer device 100a. In this embodiment, the communication channel releasing unit 156 confirms the priority held by the priority holding unit 152 (priority storage unit) and recognizes the continuous communication time according to the priority. That is, the continuous communication time is calculated based on the priority.
In this embodiment, the continuous communication time is calculated to be shorter as the priority is higher.
This is because a reader / writer device with a high priority frequently communicates with the tag 300, so the number of tags 300 that must be communicated at one time is relatively small, and therefore communication necessary for one communication is required. This is because the time is short. On the other hand, since the reader / writer device with low priority has few opportunities to communicate with the tag 300, it is assumed that it is necessary to communicate with a large number of tags 300 in one communication. This is because the necessary communication time becomes longer.

  In addition, when the priority is high, the opportunity for acquiring the communication channel is increased, but the time for one communication is shortened, so that the fairness of the communication channel distribution can be ensured. This prevents the reader / writer device manufacturer or user from setting the priority level unnecessarily, so that an appropriate priority level can be set.

  The continuous communication time may be calculated before communication with the tag 300 is started.

In S43, the communication channel releasing unit 156 compares the continuous communication time calculated in S42 with the actual communication time measured by the timer 142. If the continuous communication time has elapsed, the communication channel releasing unit 156 proceeds to the next step (S44). move on.
If the continuous communication time is not reached, the communication with the tag 300 is continued.
Although not explicitly shown in FIG. 10, the process proceeds to the next step (S44) also when the communication with the tag 300 ends before the continuous communication time elapses.

  In the inter-tag communication ending step (S44), the communication with the tag 300 is ended.

In S44, the transmission unit 110 and the reception unit 120 of the reader / writer device 100a end the communication with the tag 300. The transmission unit 110 stops the emission of electric power supply radio waves to the tag 300. As a result, the communication channel is released, and other reader / writer devices can use the communication channel.
Further, the communication channel opening unit 156 stops the measurement of the communication time by the timer 142 built in the reader / writer device 100a.

  The reader / writer device 100a does not immediately communicate when the communication is terminated due to the continuous communication time being exceeded. Specifically, the next communication is not started at least until the waiting time of all the reader / writer devices has elapsed. When the setting is made such that the waiting time becomes longer as the priority is lower as in the first embodiment, the waiting time is longer than the waiting time of the reader / writer device having the lowest priority. This gives all reader / writer devices an opportunity to acquire a communication channel.

  As described above, depending on the channel acquisition priority, each reader / writer is provided with different inter-tag communication time (the communication time between continuous tags with a high priority is shorter than the communication time between continuous tags with a low priority). It is possible to maintain fairness of communication channel usage in the apparatus.

As described above, if the priority is set so that the continuous communication time is shortened, even when the user inputs the priority, the priority is set unnecessarily, and other readers There is an effect that the communication of the writer device is not disturbed.
This is because if the priority is set high, instead of making it easier to acquire a communication channel, one communication time is shortened and the necessary communication time cannot be secured. This is because an appropriate priority is set so that it can be secured.

Embodiment 4 FIG.
Embodiment 4 will be described with reference to FIGS.
Since the functional block configuration of the reader / writer device 100 (an example of a communication station device) in this embodiment is the same as that described with reference to FIG. 1 in the first embodiment, description thereof is omitted here.

  In this embodiment, an operation will be described in which the reader / writer device 100 that has started communication with the tag 300 prevents communication channel collision caused by starting communication almost simultaneously with other reader / writer devices.

  FIG. 11 is a flowchart showing an example of the operation flow of the reader / writer device 100 in this embodiment.

  In the inter-tag communication start step (S51), the communication channel acquisition priority control unit 153 (waiting time calculation unit, communication start unit) of the transmission / reception control unit 150 selects a communication channel free by the operation described in the first embodiment, for example. The transmission unit 110 and the reception unit 120 start communication with the tag 300.

  In the carrier sense execution step (S52 to S53), the communication channel being used is carrier sensed.

In S52, the carrier sense unit 130 (communication determination unit) of the reader / writer device 100 performs carrier sense for the communication channel acquired by the reader / writer device 100 and starting communication.
The carrier sense unit 130 is configured not to detect the radio wave transmitted by itself. For example, if only the signal received by the antenna 200 is detected by the directional coupler, the signal transmitted by itself is not detected. Therefore, whether or not another reader / writer device is using the communication channel. Can be detected.
Alternatively, a sensor dedicated to carrier sense may be provided separately from the antenna 200. In this case, if the sensor is installed so as to be out of the directivity range of the antenna 200 (for example, next to the antenna 200), the sensor radiated from the antenna 200 can be prevented from detecting a signal transmitted by itself. .

  In S53, the communication channel collision detection unit 157 (communication cancellation unit) of the reader / writer device 100 has detected that the other channel reader / writer device is using the communication channel that the reader / writer device 100 should have acquired. If not detected (no collision), the process proceeds to S54. If it is detected (there is a collision), the process proceeds to S55.

  In the inter-tag communication continuation step (S54), the reader / writer device 100 continues communication with the tag 300.

In S54, the transmission unit 110 and the reception unit 120 of the reader / writer device 100 continue to communicate with the tag 300 started in S51.
At this time, depending on the priority of the reader / writer device 100, the communication interruption process described in the second embodiment or the continuous communication time restriction process described in the third embodiment may be performed.

  In the inter-tag communication ending step (S55 to S56), the reader / writer device 100 ends the communication with the tag 300.

  In S55, the transmission unit 110 and the reception unit 120 of the reader / writer device 100 end (stop) the communication with the tag 300, and stop using the communication channel in which the communication channel collision detection unit 157 has detected a communication channel collision. .

  In S56, the communication channel acquisition priority control unit 153 of the reader / writer device 100 determines whether or not the communication channel other than the communication channel in which the collision is detected is being used by the carrier sense unit 130 as a result of carrier sensing. Based on the determination (channel sense), if it is an empty channel, the communication channel is acquired.

Note that it is conceivable that the colliding partner's reader / writer device 100 stops the communication as a result of detecting the collision in the same manner. In this case, the communication channel in which the collision is detected becomes free. However, when trying to communicate again on the same communication channel, a collision may occur again. This is because the reader / writer devices 100 in which collisions occur have substantially the same waiting time.
Therefore, in this embodiment, if a communication channel other than the communication channel that detected the collision is available, it is used to prevent the collision from occurring again. In the different reader / writer devices 100, since other reader / writer devices that generate interference are different, the available empty channels are different. For one reader / writer device 100, even if it is a communication channel in use, the other reader / writer device 100 may be an empty channel. This is because there is a case where communication can be performed without doing so.
Then, only when there is no other empty channel, carrier sense may be performed for a communication channel in which a collision has occurred.

Alternatively, when a collision occurs, the collision may be avoided by causing the communication channel collision detection unit 157 to randomly change the waiting time calculated by the communication channel acquisition priority control unit 153. The collision occurs because the waiting times of both reader / writer devices 100 are substantially equal.
In this case, the communication channel in which the collision has occurred is not treated specially, and may be included in the carrier sense target as with other communication channels.

  Alternatively, by randomly changing the time from the start of communication to carrier sense, the reader / writer device that previously sensed the carrier detects a collision and stops transmission, so that the reader / writer device that later sensed the carrier does not collide. You may comprise so that transmission may be continued without detecting.

  FIG. 12 is a timing chart showing an example of an operation flow when a communication collision occurs in this embodiment.

Since both the reader / writer devices 100a and 100b are in a transmission waiting state and have substantially the same priority, it is assumed that the carrier sense times are also substantially equal.
When communication of the reader / writer device 100c is stopped and the communication channel is free, the carrier sense unit 130 of the reader / writer devices 100a and 100b detects that the communication channel is free.
Since both the communication channel acquisition priority control unit 153 of the reader / writer devices 100a and 100b re-detects an empty channel in the carrier sense after the carrier sense period (waiting time) has elapsed, the channel is acquired and the transmission unit 110 acquires the channel. Start sending.

  In this example, it is assumed that the time from the start of communication to carrier sense is changed randomly. This time, the reader / writer device 100a performs carrier sense earlier than the reader / writer device 100b.

The reader / writer device 100a detects a collision by carrier sense after starting transmission, and immediately stops transmission.
Since the reader / writer device 100b performs carrier sense after the reader / writer device 100a stops transmission, the reader / writer device 100b continues transmission without detecting a collision.
The reader / writer device 100a searches for another communication channel and returns to the communication waiting state.

  As described above, by performing carrier sense for the communication channel at the timing of starting communication between tags after acquiring the communication channel, communication channel collision is prevented, and tag read-out occurs due to radio wave interference due to communication channel collision Can be prevented.

Embodiment 5 FIG.
The fifth embodiment will be described with reference to FIGS.

  FIG. 13 is a block configuration diagram showing an example of a functional block configuration of the reader / writer device 100 (100a, 100b) in this embodiment.

The reader / writer device 100 includes a transmission unit 110 (an example of a communication unit), a reception unit 120 (an example of a communication unit), a carrier sense unit 130 (an example of a communication determination unit), a control unit 140, a communication device 170, and a storage device 180. Have.
Among these, the transmission unit 110, the reception unit 120, the carrier sense unit 130, the communication device 170, and the storage device 180 are the same as those described in Embodiment 1 with reference to FIG.
The control unit 140 controls the entire reader / writer device 100. The control unit 140 includes a host PC (computer) control unit 141, a timer 142, a transmission / reception control unit 150, and an inter-reader communication control unit 143 (an example of an interrupt request notification unit and an interrupt request acquisition unit).
Among them, the host PC control unit 141, the timer 142, and the transmission / reception control unit 150 are the same as those described in the first embodiment with reference to FIG.

The inter-reader communication control unit 143 controls communication between the reader / writer devices 100.
In this embodiment, the reader / writer devices 100a and 100b are reader / writer devices constituting different systems. Accordingly, there is no signal line for connecting the reader / writer devices 100a and 100b to exchange signals. It is also assumed that communication cannot be performed via the host PC 400.

  The inter-reader communication control unit 143 communicates with other reader / writer devices by the communication device 170 used for communication with the tag 300. As a result, no additional device is required, and the manufacturing cost of the reader / writer device can be kept low. Further, any reader / writer device within the range where the communication radio wave with the tag 300 interferes can receive a signal from the communication device 170 used for communication with the tag 300. The communication can be automatically secured.

However, a communication device dedicated to inter-reader communication may be provided in addition to the communication device 170 used for communication with the tag 300, and may be used to communicate with other reader / writer devices.
Or it is good also as communicating with another reader-writer apparatus via host PC400.

In this embodiment, a reader / writer device with a high channel acquisition priority requests an interrupt permission generation interval from a reader / writer device with a low channel acquisition priority, and a reader / writer device with a low channel acquisition priority An operation for setting an interrupt permission generation interval based on a request from a reader / writer device having a high acquisition priority will be described.
Since the interrupt permission generation interval has been described in the second embodiment, the description thereof is omitted here.

The inter-reader communication control unit 143 transmits (notifies) the interrupt permission generation request (interrupt request) generated by the interrupt permission generation interval request unit 159 to other reader / writer devices using the communication device 170. Further, the communication apparatus 170 receives (acquires) an interrupt permission generation request notified by another reader / writer device.
The interrupt permission generation request includes information on the value of the interrupt permission generation interval (interval for interrupting communication) (interrupt interval information), the priority of the reader / writer device 100 that has notified the interrupt permission generation request, and the like.

FIG. 14 is a flowchart showing an example of the operation flow of the reader / writer device 100a having a high priority in this embodiment.
FIG. 15 is a flowchart showing an example of the operation flow of the reader / writer device 100b having a low priority in this embodiment.

  First, a processing flow in the reader / writer device 100a having a high channel acquisition priority will be described.

In the channel acquisition priority setting step (S11), the reader / writer device 100a having a high channel acquisition priority sets the channel acquisition priority.
Since the operation in S11 is the same as the operation of the reader / writer device 100a described in Embodiment 1 with reference to FIG. 5, the description thereof is omitted here.

  In the interrupt permission generation interval transmission step (S61 to S62), the reader / writer device 100a having a high channel acquisition priority sets an interrupt permission generation interval.

In S61, the interrupt permission generation interval request unit 159 of the reader / writer device 100a sets an interrupt permission generation interval (communication time) that is an interval for requesting the reader / writer device with a low priority to generate interrupt permission.
The interrupt permission generation interval is set, for example, by allowing the user of the system to input using an input device. Alternatively, the user of the system may input information such as a necessary tag reading interval using an input device, and the interrupt permission generation interval request unit 159 may calculate from the input information. Alternatively, the interrupt permission generation interval request unit 159 may calculate based on the information about the priority set by the priority setting unit 151 and held by the priority holding unit 152 in S11.

  In S <b> 62, the inter-reader communication control unit 143 of the reader / writer apparatus 100 a transmits an interrupt permission generation request using the communication apparatus 170. The interrupt permission generation request includes the interrupt permission generation interval (communication time and interrupt interval information) set by the interrupt permission generation interval request unit 159 in S61 and the priority of the reader / writer device 100a held by the priority holding unit 152. Information is included.

  Note that the reader / writer device 100 may not be able to determine which one has higher priority than other interfering reader / writer devices. In this case, for example, the reader / writer device 100 may behave as a low-priority reader / writer device by selecting and inputting that the user does not request the interrupt permission generation interval in S61. Alternatively, even a reader / writer device with a low priority may request an interrupt permission generation interval from another reader / writer device.

  Each step of S11 to S62 is an initial setting performed when the reader / writer device 100a is installed or when it is found that interference with another reader / writer device 100b or the like has occurred. Steps S12 and after are operations when the communication with the tag 300 is actually performed.

  The operations in S12 to S16 are the same as the operations of the reader / writer device 100a described in Embodiment 1 with reference to FIG.

  Next, a processing flow in the reader / writer device 100b having a low channel acquisition priority will be described.

  In the interrupt permission generation interval reception step (S63 to S64), the reader / writer device 100b having a low channel acquisition priority receives the interrupt permission generation interval.

  In S63, the inter-reader communication control unit 143 receives the interrupt permission generation request transmitted by the reader / writer device having a high channel acquisition priority, and acquires the value of the interrupt permission generation interval.

  In S <b> 64, the interrupt permission generation interval holding unit 160 holds (stores) the value of the interrupt permission generation interval (communication time and interrupt interval information) acquired by the inter-reader communication control unit 143 using the storage device 180.

Note that the reader / writer device 100 may not be able to determine which one has higher priority than other interfering reader / writer devices. In this case, for example, information about the priority of the reader / writer device 100 that has transmitted the interrupt permission generation request is acquired from the interrupt permission generation request received by the inter-reader communication control unit 143. The inter-reader communication control unit 143 compares the acquired priority with the priority held by the priority holding unit 152 and determines which one is higher. If the priority of the transmitted reader / writer device is higher, S64 is executed. If the priority of the transmitted reader / writer device is lower, S64 is not executed and the request is ignored.
However, if the priority of the other reader / writer device can be determined by another method, the interrupt permission generation request may not include information on the priority.

  Each step of S63 to S64 is an operation performed when an interrupt permission generation request is received from another reader / writer device. Therefore, the initial setting is often performed before the communication with the tag 300 is started. However, the initial setting is not limited to this, and may be performed between the communication with the tag 300.

  In this embodiment, the communication device 170 used for communication with the tag 300 is used to perform communication between the reader / writer devices 100 via the communication channel used for communication with the tag 300. The transmission / reception is performed during a period when communication with the tag 300 is not performed. However, when other communication means are used, it may be performed in parallel with the communication with the tag 300.

  The operations in S33 to S40 are the same as the operations of the reader / writer device 100b described in Embodiment 2 with reference to FIG.

  As described above, the reader / writer device with the high channel acquisition priority notifies the reader / writer device with the low channel acquisition priority of the interrupt permission generation request including the value of the interrupt permission generation interval, and the channel acquisition priority A low reader / writer device obtains this and generates an interrupt permission period based on this value, so that a reader / writer device with a high channel acquisition priority can realize the tag reading interval necessary for the system. It becomes.

  That is, in the configuration described in the second embodiment, the low-priority reader / writer device sets the interrupt permission generation interval only according to its own conditions. Therefore, the interfering high-priority reader / writer device An interrupt permission period is not always generated at an interval that is really necessary. However, according to this embodiment, since the interrupt permission period is generated at an interval required by the reader / writer device with high priority, the efficiency is high.

  In this embodiment, an interrupt permission generation request is notified and acquired in advance. However, if communication between the reader / writer device 100 can be performed in parallel with communication with the tag 300, an interrupt is necessary. A configuration may be adopted in which an interrupt request is notified / acquired at the time of occurrence, and an interrupt is generated each time. In that case, the interrupt request need not include information about the value of the interrupt permission generation interval. Then, more flexible interrupt control can be performed.

  The reader / writer device (communication station device) described above has the following characteristics.

  In a reader / writer device that communicates wirelessly with a tag, a carrier sense unit that senses the usage status of a communication channel, a priority setting unit that sets channel acquisition priority, and priority information set by the priority setting unit A priority holding unit to hold, and a channel acquisition priority control unit that performs communication channel acquisition priority control based on the priority set by the priority setting unit and performs communication with the tag after acquiring the communication channel. Features.

  Further, in the reader / writer device in which a low priority is set by the priority setting unit, the communication is interrupted at regular intervals during communication with the tag, and the reader / writer device in which a high priority is set by the priority setting unit It has an interrupt permission period generating unit for generating a period in which the right of use of the communication channel can be interrupted.

  In addition, when the inter-tag communication is interrupted by the interrupt permission period generation unit, information on the communication state (communication protocol, read tag ID, etc.) is retained, and communication is performed based on the retained information when inter-tag communication is resumed. It has an interrupt return unit for restarting.

  According to the priority set by the priority setting unit, a channel opening unit for controlling a continuous communication time with the tag is provided.

  In addition, at the timing when the channel acquisition priority control unit acquires a communication channel and starts communication with a tag, the carrier sense unit monitors the use state of the communication channel, and other reader / writer devices use the communication channel. It has a channel collision detection unit that stops communication and performs channel acquisition processing again when use is detected.

  Also, an interrupt permission generated by the interrupt permission period generation unit from a reader device set with a high priority by the priority setting unit to a reader device set with a low priority by the priority setting unit. It has an interrupt permission interval requesting unit for requesting a period generation interval.

  As a result, the communication channel acquisition priority is given to each reader / writer device, for example, the communication channel acquisition priority of the reader / writer device that reads the mobile tag is increased, and the reader / writer device that is transmitting is set at regular intervals. Necessary to read the mobile tag while avoiding radio wave interference between the reader / writer devices by stopping the transmission and allowing the interruption of the right to use the communication channel by another reader / writer device with a higher priority. The tag can be read in real time depending on the situation.

2 is a block configuration diagram illustrating an example of a block configuration of a reader / writer device 100 (an example of a communication station device) according to Embodiment 1. FIG. 2 is a hardware configuration diagram illustrating an example of a hardware configuration of the reader / writer device 100 according to Embodiment 1. FIG. FIG. 3 is a diagram illustrating an example of a warehouse 800 that performs security management and inventory management using a plurality of reader / writer devices 100 (100a, 100b, 100c) according to the first embodiment. FIG. 5 is a diagram illustrating an example when communication priorities in a plurality of reader / writer devices 100 are different in the first embodiment. In the first embodiment, an example of an operation flow until the two reader / writer devices 100a and 100b are in a communication waiting state and the reader / writer device 100a having a high channel acquisition priority starts communication with the tag 300 is shown. Timing diagram. FIG. 5 is a flowchart showing an example of an operation flow of the reader / writer device 100a having a high channel acquisition priority during the operation of FIG. 4 in the first embodiment. FIG. 5 is a flowchart showing an example of an operation flow of the reader / writer device 100b having a low channel acquisition priority during the operation of FIG. 4 in the first embodiment. FIG. 11 is a timing chart showing an example of an operation flow for generating an interrupt permission period at regular intervals when the reader / writer device 100b having a low channel acquisition priority is communicating with a tag 300 in the second embodiment. FIG. 8 is a flowchart showing an example of an operation flow of the reader / writer device 100b having a low channel acquisition priority during the operation of FIG. 7 in the second embodiment. FIG. 10 is a flowchart showing an example of an operation flow of the reader / writer device 100a having a high channel acquisition priority according to the third embodiment. FIG. 10 is a flowchart showing an example of the operation flow of the reader / writer device 100 in the fourth embodiment. FIG. 9 is a timing diagram illustrating an example of an operation flow when a communication collision occurs in the fourth embodiment. FIG. 10 is a block configuration diagram illustrating an example of a functional block configuration of a reader / writer device 100 (100a, 100b) according to a fifth embodiment. FIG. 10 is a flowchart illustrating an example of an operation flow of the reader / writer device 100a with high priority in the fifth embodiment. FIG. 10 is a flowchart showing an example of an operation flow of the reader / writer device 100b having a low priority in the fifth embodiment.

Explanation of symbols

  100, 100a, 100b, 100c Reader / writer device, 110 Transmitter, 120 Receiver, 130 Carrier sense, 140 Controller, 141 Host PC controller, 142 Timer, 143 Inter-reader communication controller, 150 Transmission / reception controller, 151 Priority setting unit, 152 priority holding unit, 153 communication channel acquisition priority control unit, 154 interrupt permission period generation unit, 155 interrupt return unit, 156 communication channel release unit, 157 communication channel collision detection unit, 158 interrupt permission generation interval setting Unit, 159 interrupt permission generation interval request unit, 160 interrupt permission generation interval holding unit, 170 communication device, 180 storage device, 190 CPU, 191 interface device, 192 clock device, 193 keyboard, 194 LCD, 200, 200a, 200b, 20 0c antenna, 300, 300a, 300b tag, 400 host PC, 700 employees, 800 warehouse, 810 inventory.

Claims (17)

In a communication station device that communicates with an information device,
A communication unit that communicates with the information device using the communication device;
A communication discriminating unit that discriminates whether or not another communication station device is communicating with the information device;
A communication time storage unit that stores a time for communicating with the information device using a storage device as a communication time;
An interruption time storage unit for storing the time for interrupting communication with the information device using the storage device as the interruption time;
Communication that causes the communication unit to interrupt communication with the information device when the communication time measured after the communication unit has started communication with the information device and the communication time stored in the communication time storage unit has elapsed An interruption part;
The communication interruption unit measures the elapsed time from the interruption of communication with the information device, and when the interruption time stored in the interruption time storage unit has elapsed, another communication station device is communicating with the information device. Otherwise, when the communication determination unit determines, a communication resumption unit that causes the communication unit to resume communication with the information device,
A communication station apparatus comprising: The communication station device further includes:
A priority storage unit that stores priority information indicating the priority of the communication station device using a storage device;
Based on the priority information stored in the priority storage unit, a communication time is calculated and stored in the communication time storage unit;
The communication station apparatus according to claim 1, comprising: The communication station device further includes:
When the communication interruption unit interrupts communication with the information device, the communication interruption unit has an interruption information storage unit that stores information about the communication with which the communication unit communicated with the information device using a storage device,
The communication station apparatus according to claim 2, wherein the communication resuming unit resumes communication with the information device based on information stored in the interruption information storage unit. The communication time calculation unit
The communication station apparatus according to claim 2, wherein the communication time is calculated so that the communication time becomes longer as the priority based on the priority information stored in the priority storage unit is higher. The communication station device further includes:
An interrupt request acquisition unit for acquiring an interrupt request for interrupting communication with the information device at a predetermined interval, notified to the communication station device by another communication station device;
Based on the interrupt request acquired by the interrupt request acquisition unit, a communication time is calculated and stored in the communication time storage unit;
The communication station apparatus according to claim 1, comprising: The communication station device further includes:
An interrupt request for interrupting communication with the information device at a predetermined interval, notified by the other communication station device to the communication station device, and interrupt interval information indicating a predetermined interval at which communication should be interrupted. An interrupt request acquisition unit for acquiring
When the interrupt request acquisition unit acquires an interrupt request, based on the interrupt interval information acquired by the interrupt request acquisition unit, a communication time is calculated and stored in the communication time storage unit;
The communication station apparatus according to claim 1, comprising: The communication station device further includes:
A priority storage unit that stores priority information indicating the priority of the communication station device using a storage device;
Priority information indicating the priority of the other communication station device, and an interrupt request for interrupting communication with the information device at a predetermined interval, notified to the communication station device by the other communication station device. An interrupt request acquisition unit for acquiring
When the interrupt request acquisition unit acquires an interrupt request, the priority based on the priority information acquired by the interrupt request acquisition unit is compared with the priority based on the priority information stored in the priority storage unit. A communication time calculation unit that calculates a communication time when the priority based on the priority information acquired by the interrupt request acquisition unit is higher, and stores the communication time in the communication time storage unit;
The communication station apparatus according to claim 1, comprising: The communication station device further includes:
An interrupt request notifying unit for notifying the other communication station apparatus of an interrupt request for requesting the other communication station apparatus to interrupt communication with the information apparatus at a predetermined interval. Item 4. The communication station device according to Item 1. The communication station device further includes:
Interrupt request notification for notifying other communication station devices of an interrupt request for interrupting communication with an information device at a predetermined interval and interrupt interval information indicating a predetermined interval at which communication should be interrupted The communication station apparatus according to claim 1, further comprising a unit. The communication station device further includes:
A priority storage unit that stores priority information indicating the priority of the communication station device using a storage device;
Interrupt request for notifying other communication station apparatus of interrupt request for interrupting communication with information apparatus at predetermined intervals, and priority information indicating the priority of the other communication station apparatus A notification unit;
The communication station apparatus according to claim 1, comprising: The communication station device further includes:
A priority storage unit that stores priority information indicating the priority of the communication station device using a storage device;
Based on the priority information stored in the priority storage unit, a waiting time calculating unit that calculates a waiting time until communication with the information device is started,
Measures the elapsed time since the communication determining unit determines that another communication station device is not communicating with the information device, and when the waiting time calculated by the waiting time calculating unit has elapsed, the other communication station A communication start unit that causes the communication unit to start communication with the information device when the communication determination unit determines that the device is not communicating with the information device;
The communication station apparatus according to claim 1, comprising: The waiting time calculation unit
The communication station apparatus according to claim 11, wherein the waiting time is calculated so that the waiting time becomes shorter as the priority based on the priority information stored in the priority storage unit is higher. The communication station device further includes:
Based on the priority information stored by the priority storage unit, an occupable time calculating unit that calculates an occupable time that can occupy communication with the information device;
Measures the elapsed time since the communication unit started communication with the information device, and terminates communication with the information device in the communication unit when the occupable time calculated by the occupancy time calculation unit has elapsed. A communication end unit to be
The communication station apparatus according to claim 1, comprising: The occupable time calculation unit
The communication station apparatus according to claim 13, wherein the occupable time is calculated so that the occupable time becomes shorter as the priority based on the priority information stored in the priority storage unit is higher. The communication station device further includes:
After the communication unit starts communication with the information device, if the communication determination unit determines that another communication station device is communicating with the information device, the communication unit stops communication with the information device. The communication station apparatus according to claim 1, further comprising a communication canceling unit. In a communication method for communicating with an information device,
A communication start step in which the communication unit starts communication with the information device using the communication device;
In the communication start step, the communication interruption unit measures an elapsed time since the communication unit started communication with the information device, and the communication unit communicates with the information device when a predetermined communication time has elapsed. A communication interruption process for interrupting,
In the communication interruption step, the communication resumption unit measures the elapsed time since the communication unit interrupted communication with the information device, and when a predetermined interruption time has elapsed, the other communication station device communicates with the information device. An interrupt communication determination step in which the communication determination unit determines whether or not communication is performed; and
In the interrupt communication determining step, when the communication determining unit determines that another communication station device is not communicating with the information device, the communication resuming step in which the communication unit restarts communication with the information device,
A communication method characterized by comprising: In a communication station apparatus system comprising a plurality of communication station apparatuses communicating with an information apparatus,
At least one communication station device among the plurality of communication station devices is:
A communication unit that communicates with the information device using the communication device;
A communication discriminating unit that discriminates whether or not another communication station device is communicating with the information device;
Measures the elapsed time after the communication determining unit determines that another communication station device is not communicating with the information device, and the other communication station device communicates with the information device when a predetermined waiting time has elapsed. A communication start unit that causes the communication unit to start communication with the information device when the communication determination unit determines that it is not,
Have
At least one communication station device of the plurality of communication station devices is
A communication unit that communicates with the information device using the communication device;
A communication discriminating unit that discriminates whether or not another communication station device is communicating with the information device;
A communication time storage unit that stores a time for communicating with the information device using a storage device as a communication time;
An interruption time storage unit for storing the time for interrupting communication with the information device using the storage device as the interruption time;
Communication that causes the communication unit to interrupt communication with the information device when the communication time measured after the communication unit has started communication with the information device and the communication time stored in the communication time storage unit has elapsed An interruption part;
The communication interruption unit measures the elapsed time from the interruption of communication with the information device, and when the interruption time stored in the interruption time storage unit has elapsed, another communication station device is communicating with the information device. Otherwise, when the communication determination unit determines, a communication resumption unit that causes the communication unit to resume communication with the information device,
A communication station apparatus system comprising:

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