Base radio device and communication method for base radio device

Abstract

SOLUTION: A base wireless device 16 comprises: a selection unit 36 that selects either signal transmission or transmission prohibition in a transmission reception period; and a transmission processing unit (transmission reception processing unit 34) that performs transmission processing of transmitting a signal to at least one remote wireless device 18 in a transmission reception period when the selection unit 36 selects the signal transmission, and stands by without performing the transmission processing in the transmission reception period when the selection unit 36 selects the transmission prohibition. During continuous (M+N) transmission reception periods, the selection unit 36 selects the signal transmission M times and selects the transmission prohibition N times.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] 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. [Background technology]

[0002] Patent Document 1 listed below discloses an industrial wireless communication system including 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 and the like to the base wireless device.

[0003] 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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-188868 Summary of the Invention [Problem to be solved by the invention]

[0005] 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. Therefore, while the base radio device is transmitting a signal, the signal transmission performed by the remote radio device fails. After the base radio device has finished transmitting the signal, the signal transmission performed by the remote radio device is successful.

[0006] When the base radio device has a large amount of data to transmit, it continues transmitting signals until there is no more data to transmit. As a result, it may take a long time 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 or the like decreases.

[0007] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0008] 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 a transmission process 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 process in the transmission / reception cycle, wherein the selection unit selects signal transmission M times and selects transmission prohibition N times during (M+N) consecutive transmission / reception cycles.

[0009] A second aspect of the present invention is a communication method of 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, if signal transmission is selected in the selection step, performing a transmission process of transmitting a signal to at least one of the remote radio devices in the transmission / reception cycle, and, if transmission prohibition is selected in the selection step, waiting without performing the transmission process in the transmission / reception cycle, wherein, in the selection step, signal transmission is selected M times and transmission prohibition is selected N times during (M+N) consecutive transmission / reception cycles. [Effects of the Invention]

[0010] The present invention reduces the time it takes for a remote wireless device to successfully transmit a signal. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of a wireless communication system. [Figure 2] FIG. 2 is a diagram showing functional blocks of the wireless communication system of the first embodiment. [Figure 3] FIG. 3 is a flowchart showing the processing of the first embodiment. [Figure 4] FIG. 4 is a diagram showing functional blocks of the counting unit of the second embodiment. [Figure 5] FIG. 5 is a flowchart showing the processing of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] [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 of the first embodiment. The industrial wireless communication system 10 includes one computer 12 and at least one communication network 14. One 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, etc. (not shown).

[0013] 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 includes an interface (not shown) for transmitting and receiving data via wire or wirelessly. 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.

[0014] One or more robots or the like are equipped with actuators and sensors. The actuators operate according to instructions from the computer 12. The sensors detect the operation of the robots. In this specification, the sensors and actuators are collectively referred to as S / A 20. The actuators receive control signals transmitted from the computer 12 via the base radio device 16 and the remote radio device 18. The sensors transmit sensor signals indicating the detection results to the computer 12 via the base radio device 16 and the remote radio device 18.

[0015] [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 .

[0016] The base calculation unit 22 has a processing circuit. The processing circuit may be a processor such as a CPU. The processing circuit may be an integrated circuit such as an ASIC or FPGA. The processor executes a program stored in the base storage 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.

[0017] Based on the hopping information, the frequency switching unit 32 switches the frequency of the channel used by the base communication unit 26. The hopping information is stored in the base storage unit 24.

[0018] 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 transmission processing. When the selection unit 36 ​​selects transmission prohibition, the transmission / reception processing unit 34 waits without performing transmission processing. While waiting, the transmission / reception processing unit 34 performs processing to receive a 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 (ACK) transmitted from the remote radio device 18.

[0019] 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.

[0020] 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 and reception processing unit 34 during (M+N) consecutive transmission and reception cycles. The processes performed by the transmission and reception processing unit 34 are transmission processes and standby processes. In other words, the counting unit 38 counts the total number of times the transmission and reception processing unit 34 performed transmission processes and the number of times the transmission and reception processing unit 34 standby processes during (M+N) consecutive transmission and reception cycles.

[0021] The input / output control unit 40 uses the base interface 28 to perform a process of transmitting a sensor signal received from the remote wireless device 18 to the computer 12. The input / output control unit 40 also uses the base interface 28 to perform a process of receiving a control signal transmitted by the computer 12.

[0022] The base storage unit 24 has a volatile memory and a non-volatile memory. Examples of the volatile memory include RAM. Examples of the 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, predetermined programs and predetermined numerical values. The base storage unit 24 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 part of the base storage unit 24 may be provided in a processor or integrated circuit as described above.

[0023] The base storage unit 24 stores a selection order as a predetermined rule. This selection order specifies whether to select signal transmission or transmission prohibition in each of the first to (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 the number of remote radio devices 18 is 15, M is set to 10 and N is set to 3. For example, if the number of remote radio devices 18 is 31, M is set to 9 and N is set to 3. For example, if the number of remote radio devices 18 is 63, M is set to 8 and N is set to 3. For example, if the number of remote radio devices 18 is 127, 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 storage unit 24 may store one pattern of selection order or multiple patterns of selection orders.

[0024] 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.

[0025] The base interface 28 has an input / output interface for wired communication with the computer 12 .

[0026] [1-3 Configuration of remote radio 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.

[0027] The remote calculation unit 42 has a processing circuit. The processing circuit may be a processor such as a CPU. The processing circuit may 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 performs a process of transmitting a control signal to the S / A 20 using the remote interface 48. The processor also performs a process of receiving a sensor signal from the S / A 20 using the remote interface 48. The processor also performs a process of receiving a signal from the base radio device 16 using the remote communication unit 46. The processor also performs a process of transmitting a signal to the base radio device 16 using the remote communication unit 46. The processor also switches the frequency of the channel used for communication with the remote radio device 18 based on the hopping information.

[0028] The remote storage unit 44 has a volatile memory and a non-volatile memory. Examples of the volatile memory include RAM. Examples of the 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, predetermined programs and predetermined numerical values. The remote storage unit 44 stores hopping information. The hopping information includes information on hopping patterns and information on transmission and reception cycles. At least a part of the remote storage unit 44 may be provided in a processor or integrated circuit such as those described above.

[0029] 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.

[0030] The remote interface 48 has an input / output interface for performing wired communication with the S / A 20. The remote interface 48 may also have a wireless interface for performing short-range wireless communication with the S / A 20.

[0031] [1-4 Processing performed by the base radio device 16] The processing of the base radio device 16 related to transmission will be described using 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 starts.

[0032] 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 the selection order, signal transmissions may be assigned to all of the first M transmission / reception cycles among (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 signal transmissions in succession. Next, the selection unit 36 ​​selects N transmission prohibitions in succession. As another example of the 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.

[0033] In step S1, the frequency switching unit 32 switches the channel frequency in accordance with the hopping pattern stored in the base storage unit 24. When step S1 ends, the process proceeds to step S2.

[0034] 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.

[0035] When the process 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, 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.

[0036] When the process moves from step S2 to step S4, the selection unit 36 ​​determines whether the count value C is less than (M+N). The process 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), the process moves to step S6. On the other hand, if the count value C has reached (M+N) (step S4: NO), the process moves to step S5.

[0037] When the process moves from step S4 to step S5, both M transmission processes and N waiting processes have already been completed. In this case, the counting unit 38 resets the count value C of the counter 380 to zero. That is, 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, the process moves to step S6.

[0038] When the process proceeds from step S4 or step S5 to step S6, the counting unit 38 adds 1 to the count value C of the counter 380. When step S6 ends, the process proceeds to step S7.

[0039] In step S7, the selection unit 36 ​​selects either signal transmission or transmission prohibition based on the selection order stored in the base storage unit 24. The selection unit 36 ​​can determine which of the (M+N) transmission and reception cycles the current transmission and reception cycle corresponds to, based on the count value C. For example, when the count value C is X, the selection unit 36 ​​determines that the current transmission and reception cycle is the Xth transmission and reception cycle out of the (M+N) transmission and reception cycles. In this case, the selection unit 36 ​​selects the process assigned to the Xth order in the selection order. When signal transmission is assigned to the Xth order, the selection unit 36 ​​selects signal transmission. When transmission prohibition is assigned to the Xth order, the selection unit 36 ​​selects transmission prohibition.

[0040] If the selection unit 36 ​​selects signal transmission in step S7 (step S8: signal transmission), the process 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, the process for this transmission / reception cycle ends.

[0041] If the selector 36 selects transmission prohibition in step S7 (step S8: transmission prohibition), the transmission / reception processor 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 processor 34 performs processing to receive the signal.

[0042] In the first embodiment, the transmission and reception processing unit 34 is forced to wait for N transmission and reception cycles out of (M+N) transmission and reception cycles, even if there is data to transmit. The transmission and reception processing unit 34 can perform reception processing during these N transmission and reception cycles. In other words, during these N transmission and 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, it is possible to shorten the time it takes for the remote radio device 18 to successfully transmit a signal.

[0043] [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 radio device 16 according to the second embodiment is generally the same as the configuration of the base radio device 16 according to the first embodiment. The configuration of the remote radio device 18 according to the second embodiment is the same as the configuration of the remote radio device 18 according to the first embodiment.

[0044] 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 below. Fig. 4 is a diagram showing functional blocks of a 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 and reception processing unit 34. The counting unit 38 uses the second counter 382 to count the number of times the transmission and reception processing unit 34 has been on standby.

[0045] The base storage unit 24 of the second embodiment stores an algorithm as the predetermined rule. This algorithm defines a method for the selection unit 36 ​​to select either signal transmission or transmission prohibition. An example of this algorithm is shown in FIG. 5.

[0046] [2-2 Processing performed by the base radio device 16] The processing of the base radio device 16 related to transmission will be described using 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 entire processing starts.

[0047] 5 is an example of a process in which the selector 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 selector 36 selects signal transmissions in 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 reaches N, the selector 36 selects signal prohibition in all remaining transmission / reception cycles.

[0048] In step S11, the frequency switching unit 32 switches the channel frequency in accordance with the hopping pattern stored in the base storage unit 24. When step S11 ends, the process proceeds to step S12.

[0049] In step S12, the transmission / reception processing unit 34 determines whether there is data to be transmitted to the S / A 20. If there is data to be transmitted (step S12: YES), the process proceeds to step S14. On the other hand, if there is no data to be transmitted (step S12: NO), the process proceeds to step S13.

[0050] 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.

[0051] When the process proceeds from step S12 to step S14, the selection unit 36 ​​determines whether the sum (C1+C2) of the count values ​​C1 and C2 is less than (M+N). The process performed here is to determine 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), the process proceeds to step S16. On the other hand, if the sum (C1+C2) has reached (M+N) (step S14: NO), the process proceeds to step S15.

[0052] When the process 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, the process moves to step S16.

[0053] 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.

[0054] When the process moves from step S16 to step S17, the selector 36 selects transmission prohibition. When step S17 ends, the process moves to step S24. In this case, the transmission / reception processor 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 processor 34 performs processing to receive the signal.

[0055] When the process proceeds 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 proceeds to step S20. On the other hand, if the count value C2 has reached N (step S18: NO), the process proceeds to step S19.

[0056] When the process proceeds from step S18 to step S19, the selector 36 selects signal transmission. When step S19 ends, the process proceeds to step S22.

[0057] When the process 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, the process proceeds to step S21.

[0058] If the selection unit 36 ​​selects signal transmission in step S20 (step S21: transmit signal), the process proceeds to step S22. On the other hand, if the selection unit 36 ​​selects transmission prohibition in step S20 (step S21: transmit transmission), the process 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.

[0059] When the process proceeds 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, the process proceeds to step S23.

[0060] In step S23, the counting unit 38 adds 1 to the count value C1 of the first counter 381. When step S23 ends, the processing in this transmission / reception cycle ends.

[0061] When the process moves from step S17 or step S21 to step S24, the counting unit 38 adds 1 to the count value C2 of the second counter 382. When step S24 ends, the process for this transmission / reception cycle ends.

[0062] 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, similar to the first embodiment, according to the second embodiment, it is possible to shorten the time it takes for the remote radio device 18 to successfully transmit a signal.

[0063] [3 Inventions Obtained from the Embodiments] The invention that can be understood from the above embodiment will be described below.

[0064] 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 selects transmission prohibition N times for each of (M+N) consecutive transmission / reception cycles.

[0065] According to 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, according to the above configuration, it is possible to shorten the time it takes for the remote radio device 18 to successfully transmit a signal.

[0066] 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.

[0067] In the first aspect, the selection unit 36 ​​may select between the signal transmission and the transmission prohibition based on a selection order determined by the predetermined rule.

[0068] In the first aspect, the selector 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.

[0069] 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, and if the number of times the signal transmission is selected when the number of times the transmission prohibition is selected reaches N before the number of times the signal transmission is selected M, select the signal transmission for the remaining transmission / reception cycle.

[0070] A second aspect of the present invention is a communication method of a base radio device 16 that transmits and receives signals with at least one remote radio device 18 in a transmission / reception cycle, wherein 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 performing a transmission process 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 process in the transmission / reception cycle if transmission prohibition is selected in the selection step, and in the selection step, the signal transmission is selected M times and the transmission prohibition is selected N times for each of (M+N) consecutive transmission / reception cycles. [Explanation of symbols]

[0071] 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

1. 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 selecting the signal transmission in M ​​transmission / reception cycles and the transmission prohibition in N transmission / reception cycles among the consecutive (M+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.

2. 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, selecting the signal transmission in M ​​transmission / reception cycles and the transmission prohibition in N transmission / reception cycles among the consecutive (M+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.

Images