JP7735700B2 - Base radio device and communication method for base radio device - Google Patents

Description

The present invention relates to a base radio device that transmits and receives signals to and from at least one remote radio device in a transmission/reception cycle, and a communication method for the base radio device.

Patent Document 1, shown below, describes an industrial wireless communication system that includes a computer and multiple communication networks. The computer manages and controls multiple robots and the like. Each communication network includes one base wireless device and multiple remote wireless devices. The base wireless device is connected to the computer. Meanwhile, the remote wireless devices are connected to sensors and actuators. The sensors and actuators are provided on the robots and the like. For example, the base wireless device transmits signals to each remote wireless device to instruct the actuator to operate. Meanwhile, each remote wireless device transmits signals indicating the sensor detection results, etc., to the base wireless device.

In the wireless communication system of Patent Document 1, the base radio device and multiple remote radio devices hop frequencies at a predetermined cycle. This prevents radio wave interference between the base radio device and surrounding radio devices. Similarly, radio wave interference between the remote radio devices and surrounding radio devices is also prevented. In this specification, the frequency hopping cycle is referred to as the transmission/reception cycle.

Japanese Patent Application Laid-Open No. 2017-188868

While the base radio device is transmitting a signal to the remote radio device, it cannot receive the signal transmitted by the remote radio device. As a result, while the base radio device is transmitting a signal, the remote radio device's signal transmission fails. After the base radio device has finished transmitting the signal, the remote radio device's signal transmission is successful.

When the base radio device has a large amount of data to send, it continues to send signals until there is no more data to send. This can result in a long time being required for the signal transmission from the remote radio device to the base radio device to be completed. As a result, the communication speed of the wireless communication system decreases, and the processing power of the robot, etc. decreases.

The present invention aims to solve the above-mentioned problems.

A first aspect of the present invention is a base radio device that transmits and receives signals with at least one remote radio device in a transmission/reception cycle, and includes a selection unit that selects either signal transmission or transmission prohibition in the transmission/reception cycle, and a transmission processing unit that, if the selection unit selects signal transmission, performs transmission processing to transmit a signal to at least one of the remote radio devices in the transmission/reception cycle, and, if the selection unit selects transmission prohibition, waits without performing the transmission processing in the transmission/reception cycle, wherein the selection unit selects signal transmission M times and transmission prohibition N times during (M+N) consecutive transmission/reception cycles.

A second aspect of the present invention is a communication method for a base radio device that transmits and receives signals with at least one remote radio device in a transmission/reception cycle, wherein the base radio device performs a selection step of selecting either signal transmission or transmission prohibition in the transmission/reception cycle, and a transmission processing step of transmitting a signal to at least one of the remote radio devices in the transmission/reception cycle if signal transmission is selected in the selection step, and waiting without performing the transmission processing in the transmission/reception cycle if transmission prohibition is selected in the selection step, wherein the signal transmission is selected M times and transmission prohibition is selected N times during (M+N) consecutive transmission/reception cycles in the selection step.

The present invention can reduce the time it takes for a remote wireless device to successfully transmit a signal.

FIG. 1 is a diagram showing the configuration of a wireless communication system. FIG. 2 is a diagram showing functional blocks of the wireless communication system of the first embodiment. FIG. 3 is a flowchart showing the processing of the first embodiment. FIG. 4 is a diagram showing functional blocks of the counting unit of the second embodiment. FIG. 5 is a flowchart showing the process of the second embodiment.

[1 First Embodiment]
[1-1 Configuration of wireless communication system 10]
Fig. 1 is a diagram showing the configuration of a wireless communication system 10. Fig. 2 is a diagram showing functional blocks of the wireless communication system 10 according to the first embodiment. The industrial wireless communication system 10 includes one computer 12 and at least one communication network 14. The communication network 14 includes one base wireless device 16 and multiple remote wireless devices 18. The industrial facility is provided with one or more robots or the like (not shown).

The computer 12 monitors and controls one or more robots, etc. The computer 12 may include, for example, a PLC (programmable logic controller). The computer 12 is equipped with an interface (not shown) for wired or wireless transmission and reception. The computer 12 transmits signals to the base radio device 16 via the interface. The computer 12 also receives signals transmitted from the base radio device 16 via the interface.

One or more robots, etc., are equipped with actuators and sensors. The actuators operate according to instructions from the computer 12. The sensors detect the movement of the robots. In this specification, the sensors and actuators are collectively referred to as S/A 20. The actuators receive control signals sent from the computer 12 via the base radio device 16 and remote radio device 18. The sensors send sensor signals indicating the detection results to the computer 12 via the base radio device 16 and remote radio device 18.

[1-2 Configuration of base radio device 16]
As shown in FIG. 2, the base radio device 16 includes a base calculation unit 22, a base storage unit 24, a base communication unit 26, and a base interface 28.

The base calculation unit 22 has a processing circuit. The processing circuit may be a processor such as a CPU. The processing circuit may also be an integrated circuit such as an ASIC or FPGA. The processor executes programs stored in the base memory unit 24 to function as a frequency switching unit 32, a transmission/reception processing unit 34, a selection unit 36, a counting unit 38, and an input/output control unit 40.

The frequency switching unit 32 switches the frequency of the channel used by the base communication unit 26 based on the hopping information. The hopping information is stored in the base storage unit 24.

When the selection unit 36 selects signal transmission, the transmission/reception processing unit 34 performs processing to transmit a signal to the remote radio device 18 using the transmission circuit of the base communication unit 26. The processing to transmit a signal is simply referred to as the transmission processing. When the selection unit 36 selects transmission prohibition, the transmission/reception processing unit 34 waits without performing the transmission processing. While waiting, the transmission/reception processing unit 34 performs processing to receive the signal transmitted by the remote radio device 18 using the reception circuit of the base communication unit 26. The transmission/reception processing unit 34 transmits one packet of signal in one transmission/reception cycle. The transmission/reception processing unit 34 performs a series of processes when transmitting one packet of signal. In other words, the transmission processing includes processing to transmit a signal and processing to receive an acknowledgment response (ACK) transmitted from the remote radio device 18.

The selection unit 36 selects either signal transmission or transmission prohibition in each transmission/reception cycle. The selection unit 36 selects signal transmission M times and transmission prohibition N times during (M+N) consecutive transmission/reception cycles. The selection unit 36 makes the selection based on a predetermined rule. In the first embodiment, the predetermined rule is the selection order stored in the base storage unit 24.

The counting unit 38 has a counter 380. The counting unit 38 uses the counter 380 to count the number of processes performed by the transmission/reception processing unit 34 during (M+N) consecutive transmission/reception cycles. The processes performed by the transmission/reception processing unit 34 include transmission processes and standby. In other words, the counting unit 38 counts the total number of times the transmission/reception processing unit 34 performed transmission processes and the number of times the transmission/reception processing unit 34 standbyd during (M+N) consecutive transmission/reception cycles.

The input/output control unit 40 uses the base interface 28 to process sensor signals received from the remote wireless device 18 and transmit them to the computer 12. The input/output control unit 40 also uses the base interface 28 to process control signals transmitted by the computer 12.

The base memory unit 24 has volatile memory and non-volatile memory. Examples of volatile memory include RAM. Examples of non-volatile memory include ROM and flash memory. The volatile memory stores data acquired from the outside. The volatile memory also stores data calculated by the base calculation unit 22. The non-volatile memory stores, for example, specified programs and specified numerical values. The base memory unit 24 also stores hopping information. The hopping information includes information on hopping patterns and information on transmission and reception cycles. This hopping information is also stored in the remote radio device 18. At least a portion of the base memory unit 24 may be provided in a processor or integrated circuit such as those described above.

The base memory unit 24 stores a selection order according to a predetermined rule. This selection order specifies whether signal transmission or transmission prohibition is to be selected in each of the (M+N) consecutive transmission/reception cycles from the first transmission/reception cycle to the (M+N)th transmission/reception cycle. M and N are set according to the number of remote radio devices 18 included in one communication network 14. For example, if there are 15 remote radio devices 18, M is set to 10 and N is set to 3. For example, if there are 31 remote radio devices 18, M is set to 9 and N is set to 3. For example, if there are 63 remote radio devices 18, M is set to 8 and N is set to 3. For example, if there are 127 remote radio devices 18, M is set to 7 and N is set to 3. Note that M and N may be other numerical values. Note that the base memory unit 24 may store one pattern of selection order, or multiple patterns of selection orders.

The base communication unit 26 has a communication circuit. The communication circuit includes a transmitting circuit and a receiving circuit. The base communication unit 26 transmits signals to the remote radio device 18. The base communication unit 26 also receives signals transmitted by the remote radio device 18.

The base interface 28 has an input/output interface for wired communication with the computer 12.

[1-3 Configuration of the remote wireless device 18]
As shown in FIG. 2, the remote wireless device 18 includes a remote computing unit 42 , a remote storage unit 44 , a remote communication unit 46 , and a remote interface 48 .

The remote calculation unit 42 has a processing circuit. The processing circuit may be a processor such as a CPU. The processing circuit may also be an integrated circuit such as an ASIC or FPGA. The processor performs various processes by executing programs stored in the remote storage unit 44. For example, the processor uses the remote interface 48 to send control signals to the S/A 20. The processor also uses the remote interface 48 to receive sensor signals from the S/A 20. The processor uses the remote communication unit 46 to receive signals from the base radio device 16. The processor also uses the remote communication unit 46 to transmit signals to the base radio device 16. The processor also switches the frequency of the channel used for communication with the remote radio device 18 based on hopping information.

The remote memory unit 44 has volatile memory and non-volatile memory. Examples of volatile memory include RAM. Examples of non-volatile memory include ROM and flash memory. The volatile memory stores data acquired from the outside. The volatile memory stores data calculated by the remote calculation unit 42. The non-volatile memory stores, for example, specified programs and specified numerical values. The remote memory unit 44 stores hopping information. The hopping information includes hopping pattern information and transmission/reception cycle information. At least a portion of the remote memory unit 44 may be provided in a processor or integrated circuit such as those described above.

The remote communication unit 46 has a communication circuit. The communication circuit includes a transmitting circuit and a receiving circuit. The remote communication unit 46 transmits signals to the base radio device 16. The remote communication unit 46 also receives signals transmitted by the base radio device 16.

The remote interface 48 has an input/output interface for wired communication with the S/A 20. The remote interface 48 may also have a wireless interface for short-range wireless communication with the S/A 20.

[1-4 Processing performed by the base radio device 16]
The processing of the base radio device 16 related to transmission will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the processing of the first embodiment. The base calculation unit 22 executes the processing shown in Fig. 3 for each transmission/reception period. The counting unit 38 resets the count value C of the counter 380 to zero before all processing is started.

The process shown in FIG. 3 is an example of a process in which the selection unit 36 selects M signal transmissions and N transmission prohibitions based on a selection order. As an example of a selection order, signal transmissions may be assigned to all of the first M transmission/reception cycles of (M+N) transmission/reception cycles, and transmission prohibitions may be assigned to all of the remaining N transmission/reception cycles. In this case, the selection unit 36 selects M consecutive signal transmissions. Next, the selection unit 36 selects N consecutive transmission prohibitions. As another example of a selection order, M signal transmissions and N transmission prohibitions may be randomly assigned to (M+N) transmission/reception cycles. Note that if the base storage unit 24 stores multiple selection orders, the selection unit 36 may change the selection order used every (M+N) transmission/reception cycles.

In step S1, the frequency switching unit 32 switches the channel frequency according to the hopping pattern stored in the base memory unit 24. When step S1 is completed, processing proceeds to step S2.

In step S2, the transmission/reception processing unit 34 determines whether there is data to be transmitted to the S/A 20. For example, the data to be transmitted may be a control signal obtained from the computer 12. If there is data to be transmitted (step S2: YES), the process proceeds to step S4. On the other hand, if there is no data to be transmitted (step S2: NO), the process proceeds to step S3.

When processing moves from step S2 to step S3, the counting unit 38 sets the count value C of the counter 380 to zero. When step S3 ends, processing for this transmission/reception cycle ends. Note that if any one of the remote radio devices 18 transmits a signal to the base radio device 16 during this transmission/reception cycle, the transmission/reception processing unit 34 performs processing to receive the signal.

When processing moves from step S2 to step S4, the selection unit 36 determines whether the count value C is less than (M+N). The processing performed here is to determine whether M transmission processes and N waiting processes have both been completed at that point. If the count value C is less than (M+N) (step S4: YES), processing moves to step S6. On the other hand, if the count value C has reached (M+N) (step S4: NO), processing moves to step S5.

When processing moves from step S4 to step S5, both M transmission processes and N waiting processes have already been completed at that point. In this case, the counting unit 38 resets the count value C of the counter 380 to zero. In other words, the counting unit 38 restarts counting the number of processes performed by the transmission/reception processing unit 34 from zero. When step S5 is completed, processing moves to step S6.

When processing proceeds from step S4 or step S5 to step S6, the counting unit 38 increments the count value C of the counter 380 by 1. When step S6 is completed, processing proceeds to step S7.

In step S7, the selection unit 36 selects either signal transmission or transmission prohibition based on the selection order stored in the base memory unit 24. The selection unit 36 can determine which of the (M+N) transmission/reception cycles the current transmission/reception cycle corresponds to, based on the count value C. For example, if the count value C is X, the selection unit 36 determines that the current transmission/reception cycle is the Xth transmission/reception cycle out of the (M+N) transmission/reception cycles. In this case, the selection unit 36 selects the process assigned to the Xth order in the selection order. If signal transmission is assigned to the Xth order, the selection unit 36 selects signal transmission. If transmission prohibition is assigned to the Xth order, the selection unit 36 selects transmission prohibition.

If the selection unit 36 selects signal transmission in step S7 (step S8: signal transmission), processing proceeds to step S9. In step S9, the transmission/reception processing unit 34 performs transmission processing. The transmission/reception processing unit 34 transmits data using the base communication unit 26. When step S9 ends, processing for this transmission/reception cycle ends.

If the selection unit 36 selects transmission prohibition in step S7 (step S8: transmission prohibition), the transmission/reception processing unit 34 waits without performing transmission processing in the current transmission/reception cycle. In other words, the base radio device 16 creates an opportunity to receive signals transmitted by the remote radio devices 18. When any one of the remote radio devices 18 transmits a signal to the base radio device 16, the transmission/reception processing unit 34 performs processing to receive the signal.

In the first embodiment, the transmission/reception processing unit 34 is forced to wait for N of the (M+N) transmission/reception cycles, even if there is data to transmit. The transmission/reception processing unit 34 can perform reception processing during these N transmission/reception cycles. In other words, during these N transmission/reception cycles, any one of the remote radio devices 18 can transmit a signal to the base radio device 16. Therefore, according to the first embodiment, the time required for the remote radio device 18 to successfully transmit a signal can be shortened.

[2 Second Embodiment]
[2-1 Configuration]
The configuration of the wireless communication system 10 according to the second embodiment is the same as the configuration of the wireless communication system 10 according to the first embodiment. The configuration of the base wireless device 16 according to the second embodiment is generally the same as the configuration of the base wireless device 16 according to the first embodiment. The configuration of the remote wireless device 18 according to the second embodiment is the same as the configuration of the remote wireless device 18 according to the first embodiment.

Regarding the configuration of the base radio device 16 according to the second embodiment, differences from the configuration of the base radio device 16 according to the first embodiment will be described. Figure 4 is a diagram showing the functional blocks of the counting unit 38 according to the second embodiment. The counting unit 38 according to the second embodiment has a first counter 381 and a second counter 382. The counting unit 38 uses the first counter 381 to count the number of transmission processes performed by the transmission/reception processing unit 34. The counting unit 38 uses the second counter 382 to count the number of times the transmission/reception processing unit 34 has been on standby.

In the second embodiment, the base storage unit 24 stores an algorithm as the predetermined rule. This algorithm defines the method by which the selection unit 36 selects either signal transmission or transmission prohibition. An example of this algorithm is shown in Figure 5.

[2-2 Processing performed by the base radio device 16]
The processing of the base radio device 16 related to transmission will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the processing of the second embodiment. The base calculation unit 22 executes the processing shown in Fig. 5 for each transmission/reception period. Note that the counting unit 38 resets both the count value C1 of the first counter 381 and the count value C2 of the second counter 382 to zero before the start of all processing.

The process shown in FIG. 5 is an example of a process in which the selection unit 36 randomly selects M signal transmissions and N transmission prohibitions. However, if the number of times transmission prohibitions have been selected reaches N before the number of times signal transmissions have been selected reaches M, the selection unit 36 selects signal transmissions for all remaining transmission/reception cycles. Conversely, if the number of times signal transmissions have been selected reaches M before the number of times signal prohibitions have been selected N, the selection unit 36 selects signal prohibition for all remaining transmission/reception cycles.

In step S11, the frequency switching unit 32 switches the channel frequency according to the hopping pattern stored in the base memory unit 24. When step S11 is completed, processing proceeds to step S12.

In step S12, the transmission/reception processing unit 34 determines whether there is data to transmit to the S/A 20. If there is data to transmit (step S12: YES), the process proceeds to step S14. On the other hand, if there is no data to transmit (step S12: NO), the process proceeds to step S13.

When the process moves from step S12 to step S13, the counting unit 38 sets both the count value C1 of the first counter 381 and the count value C2 of the second counter 382 to zero. When step S13 ends, the process for this transmission/reception cycle ends. Note that if any one of the remote radio devices 18 transmits a signal to the base radio device 16 during this transmission/reception cycle, the transmission/reception processing unit 34 performs processing to receive the signal.

When processing proceeds from step S12 to step S14, the selection unit 36 determines whether the sum (C1 + C2) of count values C1 and C2 is less than (M + N). The processing performed here determines whether M transmission processes and N waiting processes have both been completed at that point. If the sum (C1 + C2) is less than (M + N) (step S14: YES), processing proceeds to step S16. On the other hand, if the sum (C1 + C2) has reached (M + N) (step S14: NO), processing proceeds to step S15.

When processing moves from step S14 to step S15, both M transmission processes and N waiting processes have already been completed. In this case, the counting unit 38 sets both the count value C1 of the first counter 381 and the count value C2 of the second counter 382 to zero. When step S15 is completed, processing moves to step S16.

In step S16, the selection unit 36 determines whether the count value C1 is less than M. The process performed here is to determine whether M transmission processes have already been completed at that point. If the count value C1 is less than M (step S16: YES), the process proceeds to step S18. On the other hand, if the count value C1 has reached M (step S16: NO), the process proceeds to step S17.

When the process moves from step S16 to step S17, the selection unit 36 selects transmission prohibition. When step S17 ends, the process moves to step S24. In this case, the transmission/reception processing unit 34 waits without performing transmission processing in the current transmission/reception cycle. In other words, the base radio device 16 creates an opportunity to receive a signal transmitted by a remote radio device 18. When any one of the remote radio devices 18 transmits a signal to the base radio device 16, the transmission/reception processing unit 34 performs processing to receive the signal.

When the process moves from step S16 to step S18, the selection unit 36 determines whether the count value C2 is less than N. The process performed here is to determine whether N transmission processes have already been completed at that point. If the count value C2 is less than N (step S18: YES), the process moves to step S20. On the other hand, if the count value C2 has reached N (step S18: NO), the process moves to step S19.

When processing proceeds from step S18 to step S19, the selection unit 36 selects signal transmission. When step S19 is completed, processing proceeds to step S22.

When processing proceeds from step S18 to step S20, the selection unit 36 randomly selects either signal transmission or transmission prohibition. The base storage unit 24 stores a known method for random selection, such as using random numbers. The selection unit 36 selects either signal transmission or transmission prohibition based on that method. When step S20 ends, processing proceeds to step S21.

If the selection unit 36 selects signal transmission in step S20 (step S21: signal transmission), processing proceeds to step S22. On the other hand, if the selection unit 36 selects transmission prohibition in step S20 (step S21: transmission prohibition), processing proceeds to step S24. In this case, the transmission/reception processing unit 34 waits without performing transmission processing in the current transmission/reception cycle. In other words, the base radio device 16 creates an opportunity to receive a signal transmitted by a remote radio device 18. When any one of the remote radio devices 18 transmits a signal to the base radio device 16, the transmission/reception processing unit 34 performs processing to receive the signal.

When proceeding from step S19 or step S21 to step S22, the transmission/reception processing unit 34 performs transmission processing. The transmission/reception processing unit 34 transmits data using the base communication unit 26. When step S22 ends, processing proceeds to step S23.

In step S23, the counting unit 38 increments the count value C1 of the first counter 381 by 1. When step S23 is completed, processing for this transmission/reception cycle ends.

When the process moves from step S17 or step S21 to step S24, the counting unit 38 increments the count value C2 of the second counter 382 by 1. When step S24 ends, processing for this transmission/reception cycle ends.

In the second embodiment, the transmission/reception processing unit 34 is forced to wait for N transmission/reception cycles out of (M+N) transmission/reception cycles, even if there is data to transmit. Therefore, as with the first embodiment, the second embodiment can shorten the time it takes for the remote radio device 18 to successfully transmit a signal.

[3 Inventions Obtained from the Embodiments]
The invention that can be understood from the above embodiment will be described below.

A first aspect of the present invention is a base radio device 16 that transmits and receives signals with at least one remote radio device 18 in a transmission/reception cycle, and includes a selection unit 36 that selects either signal transmission or transmission prohibition in the transmission/reception cycle, and a transmission processing unit (transmission/reception processing unit 34) that, if the selection unit 36 selects signal transmission, performs transmission processing to transmit a signal to at least one remote radio device 18 in the transmission/reception cycle, and, if the selection unit 36 selects transmission prohibition, waits without performing the transmission processing in the transmission/reception cycle, and the selection unit 36 selects signal transmission M times and transmission prohibition N times for each of (M+N) consecutive transmission/reception cycles.

With the above configuration, the transmission/reception processing unit 34 is forced to wait for N of the (M+N) transmission/reception cycles, even if there is data to transmit. The transmission/reception processing unit 34 can perform reception processing during these N transmission/reception cycles. In other words, during these N transmission/reception cycles, any one of the remote radio devices 18 can transmit a signal to the base radio device 16. Therefore, with the above configuration, the time required for the remote radio device 18 to successfully transmit a signal can be shortened.

In the first aspect, the base radio device 16 is provided with a memory unit (base memory unit 24) that stores predetermined rules for determining whether to select the signal transmission or the transmission prohibition, and the selection unit 36 may select either the signal transmission or the transmission prohibition in the transmission/reception cycle based on the predetermined rules.

In the first aspect, the selection unit 36 may select between signal transmission and transmission prohibition based on a selection order determined by the predetermined rule.

In the first aspect, the selection unit 36 may select the signal transmission M times in succession, and after selecting the signal transmission M times, may select the transmission prohibition N times in succession.

In the first aspect, the selection unit 36 may randomly select either the signal transmission or the transmission prohibition, and if the number of times the signal transmission is selected reaches M before the number of times the transmission prohibition is selected reaches N, select the transmission prohibition for the remaining transmission/reception cycle, or if the number of times the transmission prohibition is selected reaches N before the number of times the signal transmission is selected reaches M, select the signal transmission for the remaining transmission/reception cycle.

A second aspect of the present invention is a communication method for a base radio device 16 that transmits and receives signals with at least one remote radio device 18 in a transmission/reception cycle, in which the base radio device 16 performs a selection step of selecting either signal transmission or transmission prohibition in the transmission/reception cycle, and a transmission processing step of transmitting a signal to at least one of the remote radio devices in the transmission/reception cycle if signal transmission is selected in the selection step, and waiting without performing the transmission processing in the transmission/reception cycle if transmission prohibition is selected in the selection step, in which the base radio device 16 selects signal transmission M times and transmission prohibition N times for each of (M+N) consecutive transmission/reception cycles in the selection step.

16... base radio device 18... remote radio device 24... base storage unit (storage unit) 34... transmission/reception processing unit (transmission processing unit)
36...Selection section

Claims (2)

A base radio device that transmits and receives signals to and from at least one remote radio device in a transmission and reception cycle,
a selection unit that randomly selects either signal transmission or transmission prohibition in each of the transmission and reception periods;
a transmission processing unit that, when the selection unit selects the signal transmission, performs a transmission process of transmitting a signal to at least one of the remote radio devices in the transmission/reception cycle, and, when the selection unit selects the transmission prohibition, waits without performing the transmission process in the transmission/reception cycle;
Equipped with
The selection unit
Among the (M+N) consecutive transmission/reception cycles, the signal transmission is selected in M transmission/reception cycles and the transmission prohibition is selected in N transmission/reception cycles ;
If the number of times that the signal transmission has been selected reaches M before the number of times that the transmission prohibition has been selected reaches N, the transmission prohibition is selected without performing a process of randomly selecting either the signal transmission or the transmission prohibition in each of the remaining transmission and reception cycles among the consecutive (M+N) cycles;
If the number of times that the transmission prohibition is selected reaches N before the number of times that the signal transmission is selected reaches M, the base radio device selects the signal transmission without performing a process of randomly selecting either the signal transmission or the transmission prohibition in each of the remaining transmission and reception cycles among the consecutive (M+N) cycles . A communication method for a base radio device that transmits and receives signals to and from at least one remote radio device in a transmission and reception cycle, comprising:
The base radio equipment
a selection step of randomly selecting either signal transmission or transmission prohibition in each of the transmission and reception periods;
a transmission processing step of performing a transmission process of transmitting a signal to at least one of the remote radio devices in the transmission/reception cycle when the signal transmission is selected in the selection step, and waiting without performing the transmission process in the transmission/reception cycle when the transmission prohibition is selected in the selection step;
and
In the selecting step,
Among the (M+N) consecutive transmission/reception cycles, the signal transmission is selected in M transmission/reception cycles and the transmission prohibition is selected in N transmission/reception cycles ;
If the number of times that the signal transmission has been selected reaches M before the number of times that the transmission prohibition has been selected reaches N, the transmission prohibition is selected without performing a process of randomly selecting either the signal transmission or the transmission prohibition in each of the remaining transmission and reception cycles among the consecutive (M+N) cycles;
A communication method for a base radio device, in which, if the number of times that the transmission prohibition is selected reaches N before the number of times that the signal transmission is selected reaches M, the signal transmission is selected without performing a process of randomly selecting either the signal transmission or the transmission prohibition in each of the remaining transmission and reception cycles among consecutive (M+ N) cycles.