Remote wireless device and communication method of remote wireless device

Abstract

A remote wireless device and a communication method of a remote wireless device are provided. A remote wireless device (18) which transmits and receives signals with a base wireless device (16) in a transmission and reception cycle, includes a transmission and reception processing section (44) which performs transmission processing of signals in each of a plurality of consecutive transmission and reception cycles until transmission to the base wireless device (16) is successful, a counting section (46) which counts the number of times the transmission processing is performed, a transmission selection section (48) which selects whether to perform the transmission processing or to stand by in the next transmission and reception cycle according to a predetermined rule if the count value (N) of the counting section is a predetermined number of times or more, and a transmission prohibition section (50) which prohibits the transmission processing by the transmission and reception processing section (44) if the stand by is selected by the transmission selection section (48).

Description

Technical Field

[0001] This invention relates to a remote wireless device that transmits and receives signals with a basic wireless device in a transmit-receive cycle, and a communication method for the remote wireless device. Background Technology

[0002] Japanese Patent Application Publication No. 2017-188868 discloses an industrial wireless communication system equipped with a computer and multiple communication networks. The computer manages and controls multiple robots, etc. Each communication network has a basic wireless device and multiple remote wireless devices. The basic wireless device is connected to the computer. On the other hand, the remote wireless devices are connected to sensors and actuators. The sensors and actuators are installed on robots, etc. For example, the basic wireless device sends signals to each remote wireless device to instruct the actuators to operate. On the other hand, each remote wireless device sends signals to the basic wireless device indicating the detection results of the sensors, etc. In the wireless communication system of Japanese Patent Application Publication No. 2017-188868, the basic wireless device and the multiple remote wireless devices hop frequencies at a predetermined period. This prevents radio wave interference between the basic wireless device and surrounding wireless devices. Similarly, when the frequency changes, radio wave interference between the remote wireless devices and surrounding wireless devices is prevented. The period of frequency hopping is called the transmit / receive period.

[0003] In the communication network described in Japanese Patent Application Publication No. 2017-188868, multiple remote wireless devices perform frequency hopping using the same frequency hopping mode and the same transmit / receive cycle. Therefore, signal collisions between the transmitted signals of these remote wireless devices are prone to occur. When signal collisions occur, each remote wireless device retransmits its signal. In this situation, when each remote wireless device continuously retransmits signals of the same frequency with the same cycle, signal collisions repeatedly occur. Consequently, a longer time is spent until each remote wireless device completes its transmission. As a result, the communication speed of the wireless communication system decreases, and the processing power of robots, etc., is reduced. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems.

[0005] One aspect of the present invention is a remote wireless device that transmits and receives signals with a basic wireless device in a transmit-receive cycle. The remote wireless device comprises: a transmit-receive processing unit that performs signal transmission processing in each of a plurality of consecutive transmit-receive cycles until successful transmission to the basic wireless device; a counting unit that counts the number of times the transmission processing is performed; a transmission selection unit that, if the count value of the counting unit exceeds a predetermined number, selects, according to a predetermined rule, whether to perform the transmission processing or remain in standby mode in the next transmit-receive cycle; and a transmission prohibition unit that, if the transmission selection unit selects standby mode, prohibits the transmission processing performed by the transmit-receive processing unit.

[0006] Another aspect of the present invention is a communication method for a remote wireless device, wherein the remote wireless device transmits and receives signals with a base wireless device in a transmit-receive cycle. The communication method for the remote wireless device comprises: a transmit-receive processing step, wherein signal transmission processing is performed in each of a plurality of consecutive transmit-receive cycles until transmission to the base wireless device is successful; a counting step, wherein the number of times the transmission processing is performed is counted; a transmission selection step, wherein if the count value in the counting step exceeds a predetermined number, a selection is made according to a predetermined rule to perform the transmission processing or to remain in standby mode in the next transmit-receive cycle; and a transmission prohibition step, wherein the transmission processing is prohibited if standby mode is selected in the transmission selection step.

[0007] According to the present invention, the number of collisions in signals transmitted to basic wireless devices can be reduced.

[0008] The aforementioned objectives, features, and advantages will be readily understood from the following description of the embodiments with reference to the accompanying drawings. Attached Figure Description

[0009] Figure 1 It is a diagram showing the structure of a wireless communication system.

[0010] Figure 2 This is a diagram showing the functional blocks of the wireless communication system according to the first embodiment.

[0011] Figure 3 This is a flowchart illustrating the main processing of the first embodiment.

[0012] Figure 4 This is a flowchart representing the sending process.

[0013] Figure 5 This diagram illustrates an example of the transmission method in the first embodiment.

[0014] Figure 6This is a diagram showing the functional blocks of the wireless communication system according to the second embodiment.

[0015] Figure 7 This is a flowchart that uses one transmit / receive cycle to represent the transmission time slot.

[0016] Figure 8 This is a flowchart illustrating the main processing of the second embodiment.

[0017] Figure 9 This diagram illustrates an example of the transmission method in the second embodiment. Detailed Implementation

[0018] [1 First Implementation Method]

[0019] [1-1 Wireless Communication System 10]

[0020] Figure 1 This is a diagram showing the structure of the wireless communication system 10. Figure 2 This is a diagram showing the functional blocks of the wireless communication system 10 according to the first embodiment. The industrial wireless communication system 10 includes a computer 12 and at least one communication network 14. The communication network 14 includes a basic wireless device 16 and multiple remote wireless devices 18. One or more robots (not shown) are installed in the industrial equipment.

[0021] Computer 12 monitors and controls one or more robots, etc. Computer 12 may have, for example, a PLC (Programmable Logic Controller). Computer 12 has an interface (not shown) for wired or wireless transmission and reception. Computer 12 transmits signals to basic wireless device 16 via the interface. Additionally, computer 12 receives signals transmitted from basic wireless device 16 via the interface.

[0022] One or more robots, etc., are equipped with actuators and sensors. The actuators perform actions according to instructions from computer 12. The sensors detect the robot's actions. In this specification, the sensors and actuators are also collectively referred to as S / A20. The actuators receive control signals sent from computer 12 via basic wireless device 16 and remote wireless device 18. The sensors send sensor signals indicating detection results to computer 12 via basic wireless device 16 and remote wireless device 18.

[0023] [1-2 Basic Wireless Devices 16]

[0024] like Figure 2 As shown, the basic wireless device 16 includes a basic computing unit 22, a basic storage unit 24, a basic communication unit 26, and a basic interface 28.

[0025] The basic arithmetic unit 22 has processing circuitry. This processing circuitry can be a processor such as a CPU, or an integrated circuit such as an ASIC or FPGA. The processor performs various functions by executing programs stored in the basic storage unit 24. For example, the basic arithmetic unit 22 uses the basic interface 28 to process signals received from the computer 12. Additionally, the basic arithmetic unit 22 uses the basic interface 28 to process signals sent to the computer 12. Furthermore, the basic arithmetic unit 22 uses the basic communication unit 26 to process signals received from multiple remote wireless devices 18. Additionally, the basic arithmetic unit 22 uses the basic communication unit 26 to process signals sent to multiple remote wireless devices 18. Furthermore, the basic arithmetic unit 22 switches the frequency of the channel used in communication with the remote wireless devices 18 based on frequency hopping information.

[0026] The basic storage unit 24 includes 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 external sources and data processed by the basic arithmetic unit 22. The non-volatile memory stores a specified program and specified values. Furthermore, the basic storage unit 24 stores frequency hopping information shared with the remote wireless device 18. The frequency hopping information includes information about the frequency hopping mode and the transmission / reception cycle. At least a portion of the basic storage unit 24 can be housed in a processor, integrated circuit, or similar device as described above.

[0027] The basic communication unit 26 has a communication circuit. The communication circuit includes a transmitting circuit and a receiving circuit. The basic communication unit 26 transmits signals to the remote wireless device 18. In addition, the basic communication unit 26 receives signals transmitted by the remote wireless device 18.

[0028] The basic interface 28 has input / output interfaces for wired communication with the computer 12.

[0029] [1-3 Remote Wireless Device 18]

[0030] like Figure 2 As shown, the remote wireless device 18 includes a remote computing unit 32, a remote storage unit 34, a remote communication unit 36, and a remote interface 38.

[0031] The remote computing unit 32 has processing circuitry. This processing circuitry can be a processor such as a CPU, or an integrated circuit such as an ASIC or FPGA. The remote computing unit 32 performs various functions by executing programs stored in the basic storage unit 24. For example, the remote computing unit 32 functions as a frequency switching unit 42, a transceiver processing unit 44, a counting unit 46, a transmission selection unit 48, a transmission inhibit unit 50, and an input / output control unit 52.

[0032] The frequency switching unit 42 switches the frequency of the channel used by the remote communication unit 36 ​​based on frequency hopping information. The frequency hopping information is pre-stored in the remote storage unit 34.

[0033] The transceiver processing unit 44 uses the transmitting circuit of the remote communication unit 36 ​​to process the transmission of signals to the basic wireless device 16. Additionally, the transceiver processing unit 44 uses the receiving circuit of the remote communication unit 36 ​​to process the reception of signals transmitted by the basic wireless device 16. The transceiver processing unit 44 transmits a data packet signal in one transceiver cycle. The transceiver processing unit 44 performs a series of transmission processes when transmitting a data packet signal. Figure 4 The transmission process includes Clear Channel Assessment (CCA), processing of transmitted signals, and processing of receiving acknowledgment responses (ACKs) sent from the basic radio device 16.

[0034] The counting unit 46 counts the number of transmission processes performed from the start of sending a signal for a data packet until the transmission is successful.

[0035] The transmission selection unit 48 selects whether to perform transmission processing or standby in the next transmission cycle if the count value N of the counting unit 46 has exceeded a predetermined number of times. The transmission selection unit 48 makes the selection according to a predetermined rule. The predetermined rule is stored in the remote storage unit 34. The predetermined rule may be information that determines the selection order of transmission and standby. Alternatively, the predetermined rule may be an algorithm for random selection, such as an algorithm for generating pseudo-random number sequences.

[0036] The transmission prohibition unit 50 prohibits the transmission processing of the transceiver processing unit 44 when the transmission selection unit 48 selects standby mode.

[0037] The input / output control unit 52 uses the remote interface 38 to process control signals sent from the S / A20. Additionally, the input / output control unit 52 uses the remote interface 38 to process sensor signals sent from the S / A20.

[0038] The remote storage unit 34 includes 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 external sources and data processed by the remote processing unit 32. The non-volatile memory stores a specified program and specified values. Furthermore, the remote storage unit 34 stores frequency hopping information shared with the basic wireless device 16. The frequency hopping information includes information about the frequency hopping mode and the transmission / reception cycle. At least a portion of the remote storage unit 34 can be housed in a processor, integrated circuit, or similar device as described above.

[0039] The remote communication unit 36 ​​has a communication circuit. The communication circuit includes a transmitting circuit and a receiving circuit. The remote communication unit 36 ​​transmits signals to the basic wireless device 16. In addition, the remote communication unit 36 ​​receives signals transmitted by the basic wireless device 16.

[0040] The remote interface 38 has input / output interfaces for wired communication with the S / A20. The remote interface 38 may also have a wireless interface for short-range wireless communication with the S / A20.

[0041] [1-4 Processing performed in the remote wireless device 18]

[0042] [A Main Processor]

[0043] The main processing performed when the remote wireless device 18 transmits signals is described. Figure 3 This is a flowchart illustrating the main processing in the first embodiment. The remote computing unit 32 executes in each transmit / receive cycle. Figure 3 The main processing is shown. Furthermore, before executing the first main processing step, the counter unit 46 sets the count value N to zero. The count value N represents the number of transmission processes performed from the start of sending a signal for one data packet until successful transmission.

[0044] In step S1, the frequency switching unit 42 switches the channel frequency according to the frequency hopping pattern stored in the remote storage unit 34. When step S1 ends, the process proceeds to step S2.

[0045] In step S2, the transceiver processing unit 44 determines whether there is information to be transmitted to the computer 12 (transmission information). Transmission information may be, for example, a sensor signal obtained from the S / A20. If transmission information exists (step S2: Yes), processing proceeds to step S3. Conversely, if no transmission information exists (step S2: No), processing in this transceiver cycle ends.

[0046] In step S3, the counting unit 46 compares the count value N with a predetermined number of times (in this case, 5 times). The predetermined number of times is an upper limit on the number of consecutive transmission processes. The predetermined number of times is pre-stored in the remote storage unit 34. If the count value N is less than the predetermined number of times (step S3: Yes), the process proceeds to step S4. On the other hand, if the count value N is greater than or equal to the predetermined number of times (step S3: No), the process proceeds to step S7.

[0047] In the case of processing a transition from step S3 or step S8 (described later) to step S4, the transceiver processing unit 44 performs... Figure 4 The transmission process is shown. The transceiver processing unit 44 performs a series of processes in the transmission process to transmit a signal indicating the transmission of information to the basic wireless device 16. When step S4 ends, the process proceeds to step S5.

[0048] In step S5, the transceiver processing unit 44 determines whether the signal transmission was successful in the transmission process executed in step S4. If the signal transmission was successful (step S5: Yes), the process proceeds to step S6. On the other hand, if the signal transmission failed (step S5: No), the process proceeds to step S9.

[0049] In step S6, the counting unit 46 clears the count value N. At the end of step S6, the processing of the signal for the remote wireless device 18 to send a data packet ends.

[0050] When the process transitions from step S3 to step S7, the transmission selection unit 48 selects either to perform the transmission process or to remain in standby mode without performing the transmission process. The transmission selection unit 48 makes the selection according to a predetermined rule. When step S7 ends, the process transitions to step S8.

[0051] If the transmit selection unit 48 selects transmit (step S8: transmit), the process proceeds to step S4. In this case, the transmit / receive processing unit 44 executes... Figure 4 The transmission process is shown. On the other hand, if the transmission selection unit 48 selects standby (step S8: standby), the transmission prohibition unit 50 prohibits the transmission process in this transmission cycle. Furthermore, the transceiver processing unit 44 does not perform transmission processing and remains in standby mode. That is, the remote wireless device 18 relinquishes the opportunity to transmit signals to the base wireless device 16 to other remote wireless devices 18. At this time, if a remote wireless device 18 performs transmission processing, the signal transmission from that remote wireless device 18 to the base wireless device 16 is successful.

[0052] When the process transitions from step S5 to step S9, the counting unit 46 increments the count value N by 1. After step S9, the processing in this transmit / receive cycle ends.

[0053] [B Send Processing]

[0054] Figure 4 This is a flowchart illustrating the sending process. Figure 3 In step S4 of the main processing shown, steps S11 to S17, which are described below, are performed. The transmission process described below includes CCA, signal transmission, and reception and acknowledgment of ACK transmitted from the basic wireless device 16.

[0055] In step S11, the transceiver processing unit 44 performs CCA. The transceiver processing unit 44 detects radio waves using the same frequency as the channel selected at that time. When step S11 ends, the processing proceeds to step S12.

[0056] In step S12, the transceiver processing unit 44 determines whether the frequency of the channel is being used based on the execution result of CCA. If the frequency of the channel is not being used (step S12: No), the process proceeds to step S13. On the other hand, if the frequency of the channel is being used (step S12: Yes), the process proceeds to step S17.

[0057] In step S13, the transceiver processing unit 44 uses the remote communication unit 36 ​​to send a signal indicating the transmission of information to the basic wireless device 16. When step S13 ends, the processing proceeds to step S14.

[0058] In step S14, the transceiver processing unit 44 waits for an ACK sent from the basic wireless device 16 for a specified upper limit time. When the remote communication unit 36 ​​receives the ACK, the transceiver processing unit 44 detects the ACK. At this time, the transceiver processing unit 44 acknowledges that the ACK has been received. Furthermore, the upper limit time is determined by the transceiver cycle, i.e., the frequency hopping cycle. The transceiver processing unit 44 uses the remaining time until the moment of switching to the next frequency as the upper limit time. When step S14 ends, the process proceeds to step S15.

[0059] In step S15, the transceiver processing unit 44 determines whether an ACK has been detected. If the transceiver processing unit 44 detects an ACK (step S15: Yes), the process proceeds to step S16. On the other hand, if the transceiver processing unit 44 does not detect an ACK (step S15: No), the process proceeds to step S17.

[0060] In step S16, the transceiver processing unit 44 determines that the transmission was successful. When step S16 ends, processing is transferred to... Figure 3 Step S5 is shown.

[0061] On the other hand, when processing transitions from step S12 or S15 to step S17, the transceiver processing unit 44 determines that transmission has failed. When step S17 ends, processing is transferred to... Figure 3 Step S5 is shown.

[0062] [An example of sending methods 1-5]

[0063] Figure 5 This diagram illustrates an example of the transmission method in the first embodiment. Figure 5 express Figure 1 The simultaneous transmission processing of the four remote wireless devices 18 to the basic wireless device 16 resulted in a signal collision. Here, the four remote wireless devices 18 are referred to as remote wireless devices 18(A) to remote wireless devices 18(D).

[0064] Figure 5(A) to (D) represent remote wireless devices 18(A) to 18(D). Figure 5 The 1st, 2nd, ..., 10th represent the first, second, ..., tenth transmit / receive cycle after information transmission is generated in each of the remote wireless devices 18. The first to tenth transmit / receive cycles are consecutive. A blacked-out quadrilateral indicates that the transceiver processing unit 44 has performed transmission processing. A whiteed-out quadrilateral indicates that the transceiver processing unit 44 is in standby mode and is not performing transmission processing.

[0065] The transceiver processing unit 44 of remote wireless devices 18(A) to 18(D) performs transmission processing in each transmission cycle until the count value N is 5 or higher. Until the end of the fifth transmission cycle, a signal collision occurs, and the signal transmission by remote wireless devices 18(A) to 18(D) fails. After the count value N becomes 5 or higher, the transceiver processing unit 44 of remote wireless devices 18(A) to 18(D) either performs transmission processing or remains in standby mode. Figure 5 In the transmission method shown, only remote wireless device 18(C) performs the transmission process during the sixth transmit / receive cycle. Meanwhile, remote wireless devices 18(A), 18(B), and 18(D) are in standby mode. At this time, no signal collision occurs. Therefore, the signal transmission performed by remote wireless device 18(C) is successful. Similarly, thereafter, when only one remote wireless device 18 performs the transmission process, that remote wireless device 18's transmission is successful.

[0066] Furthermore, in the presence of a remote wireless device 18 connected to a frequently used S / A20, the transmission selection unit 48 of the remote wireless device 18 can use predetermined rules that facilitate transmission selection. According to this configuration, transmission information from the frequently used S / A20 can be easily transmitted to the base wireless device 16.

[0067] Thus, according to the first embodiment, each remote wireless device 18 yields its transmission opportunity to the other, thereby reducing the number of signal collisions transmitted to the base wireless device 16. Therefore, signal transmissions performed by each remote wireless device 18 are more likely to succeed at an earlier stage. As a result, the reduction in communication speed of the communication network 14 caused by signal collisions is suppressed.

[0068] [2. Second Implementation]

[0069] Similar to the first embodiment, the communication network 14 of the second embodiment is also provided in the industrial wireless communication system 10. In addition to the functions of the remote wireless device 18 of the first embodiment, the remote wireless device 18 of the second embodiment also has a selective transmission time slot 56 (…).Figure 7 () function.

[0070] [2-1 Remote Wireless Device 18]

[0071] Figure 6 This is a diagram showing the functional blocks of the wireless communication system 10 according to the second embodiment. The remote wireless device 18 of the second embodiment has all the structures of the remote wireless device 18 of the first embodiment. The symbols used for the structures of the remote wireless device 18 of the second embodiment that are common to the remote wireless device 18 of the first embodiment are the same as those used in the first embodiment. In the second embodiment, the remote computing unit 32 also functions as a time slot selection unit 54.

[0072] like Figure 7 As shown, a single transmit / receive cycle includes a transmission time t1, a reception time t2, and other times not shown (such as the handover time between transmit and receive). The transmission time t1 is the time frame used by the transceiver processing unit 44 when transmitting signals. For example, the transmission time t1 is 2100 [μsec]. The reception time t2 is the time frame used by the transceiver processing unit 44 when receiving an ACK transmitted from the basic wireless device 16. For example, the reception time t2 is 1300 [μsec]. The transmission time t1 is set to be longer than the time it takes for the transceiver processing unit 44 to perform CCA and transmit a data packet.

[0073] The time slot selection unit 54 sets multiple transmission time slots 56 with different start times for the transmission process during the transmission time t1. For example, such as... Figure 7 As shown, the time slot selection unit 54 sets multiple transmission time slots 56 whose start times differ by exactly the time of the Common Application (CCA). When the transmission time t1 is 2100 μsec, the time required for CCA is 200 μsec, and the signal time for transmitting a data packet is 1300 μsec, the time slot selection unit 54 can set four transmission time slots 56 during the transmission time t1. Furthermore, the time slot selection unit 54 can change the number of transmission time slots 56 set during the transmission time t1 based on the time required for CCA and the signal time for transmitting a data packet. The number of transmission time slots 56 and their start times are pre-stored in the remote storage unit 34.

[0074] Furthermore, before transmission processing, the time slot selection unit 54 selects one transmission time slot 56 from a plurality of transmission time slots 56 using any method. For example, the time slot selection unit 54 can select the transmission time slot 56 according to a predetermined rule. The predetermined rule may be information that determines the selection order of the transmission time slots 56. Alternatively, the predetermined rule may be an algorithm for random selection, such as an algorithm for generating a pseudo-random number sequence. As another method, the time slot selection unit 54 may select the transmission time slot 56 according to a first rule when the count value N is less than a predetermined number of determinations, and select the transmission time slot 56 according to a second rule when the count value N is greater than or equal to the number of determinations. In this case, the first rule may be information that determines the selection order of the transmission time slots 56, and the second rule may be an algorithm for random selection, such as an algorithm for generating a pseudo-random number sequence. The predetermined rule, the first rule, and the second rule are pre-stored in the remote storage unit 34.

[0075] [2-2 Processing performed by remote wireless device 18]

[0076] Figure 8 This is a flowchart illustrating the main processing in the second embodiment. The remote computing unit 32 executes in each transmit / receive cycle. Figure 8 The main processing shown. Figure 8 The main process shown is identical to the one shown, except for the addition of step S24. Figure 3 The main processing shown is essentially the same. In step S24, the time slot selection unit 54 selects the transmission time slot 56. In step S25, the transceiver processing unit 44 performs transmission processing using the selected transmission time slot 56.

[0077] [An example of sending method 2-3]

[0078] Figure 9 This diagram illustrates an example of the transmission method in the second embodiment. Figure 9 express Figure 1 The simultaneous transmission processing of the four remote wireless devices 18 to the basic wireless device 16 resulted in a signal collision. Here, the four remote wireless devices 18 are referred to as remote wireless devices 18(A) to remote wireless devices 18(D).

[0079] and Figure 5 Similarly, Figure 9 (A) to (D) represent remote wireless devices 18(A) to 18(D). Figure 9The 1st, 2nd, ..., 6th represent the first, second, ..., sixth transmit / receive cycles that occur after information transmission is generated in each of the remote wireless devices 18. The first to sixth transmit / receive cycles are consecutive. The four quadrilaterals present in each cycle represent four transmission time slots 56. The transmission time slots 56 are delayed from left to right. The blacked-out quadrilaterals represent transmission time slots 56 selected by the time slot selection unit 54 and used by the transceiver processing unit 44. Quadrilaterals marked with an X represent transmission time slots 56 not selected by the time slot selection unit 54. Additionally, the area with four white-out quadrilaterals indicates that the transceiver processing unit 44 is not performing transmission processing and is in standby mode.

[0080] In the first transmit / receive cycle, the transmit / receive processing unit 44 of remote wireless devices 18(A) to 18(D) performs transmit processing using the first transmit time slot 56. In this case, a signal collision occurs, and the transmission of signals by remote wireless devices 18(A) to 18(D) fails.

[0081] In the second transmit / receive cycle, the transceiver processing unit 44 of remote wireless device 18(A) performs transmission processing using the first transmit time slot 56. The transceiver processing units 44 of remote wireless devices 18(B) to 18(D) perform transmission processing using the second transmit time slot 56. The transceiver processing units 44 of remote wireless devices 18(B) to 18(D) detect the signal of remote wireless device 18(A) via CCA. Therefore, the transceiver processing units 44 of remote wireless devices 18(B) to 18(D) do not transmit signals. At this time, no signal collision occurs. Therefore, the signal transmission of remote wireless device 18(A) is successful.

[0082] In addition, similar to the first embodiment, the transceiver processing unit 44 of the remote wireless device 18(A) to the remote wireless device 18(D) performs transmission processing or stands up without performing transmission processing after the count value N becomes 5 or more.

[0083] Furthermore, in the presence of a remote wireless device 18 connected to a high-frequency S / A20, the time slot selection unit 54 of the remote wireless device 18 can easily select the first transmission time slot 56. In this case, the time slot selection unit 54 can use rules that facilitate the selection of the first transmission time slot 56. According to this structure, the transmission information from the high-frequency S / A20 can be easily transmitted to the base wireless device 16.

[0084] Thus, according to the second embodiment, the transmission times of each remote wireless device 18 are staggered, thereby reducing the number of signal collisions transmitted to the base wireless device 16. Therefore, signal transmission performed by each remote wireless device 18 is more likely to succeed at an earlier stage. As a result, the reduction in communication speed of the communication network 14 caused by signal collisions is suppressed.

[0085] [3 Technical Ideas Obtained from Implementation Methods]

[0086] The technical ideas that can be grasped from the above embodiments are described below.

[0087] The first aspect of the present invention is a remote wireless device 18 that transmits and receives signals with a basic wireless device 16 in a transmit-receive cycle. The remote wireless device includes: a transmit-receive processing unit 44 that performs signal transmission processing in each of a plurality of consecutive transmit-receive cycles until transmission to the basic wireless device 16 is successful; a counting unit 46 that counts the number of times the transmission processing is performed; a transmission selection unit 48 that, when the count value N of the counting unit is greater than or equal to a predetermined number, selects whether to perform the transmission processing or to standby in the next transmit-receive cycle according to a predetermined rule; and a transmission prohibition unit 50 that, when the transmission selection unit 48 selects standby, prohibits the transmission processing performed by the transmit-receive processing unit 44.

[0088] In a first embodiment of the present invention, a time slot selection unit 54 may be provided, which selects one of a plurality of transmission time slots 56 that are set in each of the transmission and reception cycles and have different start times for the transmission process, and the transmission and reception processing unit 44 uses the transmission time slot 56 selected by the time slot selection unit 54 to perform the transmission process.

[0089] In the first aspect of the present invention, the transceiver processing unit 44 may perform idle channel assessment, signal transmission, and reception of acknowledgment responses sent from the basic wireless device 16 as part of the transmission process. If the channel is detected to be in use by performing the idle channel assessment, or if the acknowledgment response is not received, the transmission is determined to have failed.

[0090] In the first aspect of the present invention, if the count value N is less than a predetermined number of determinations, the time slot selection unit 54 selects the transmission time slot 56 according to a first rule; if the count value N is greater than or equal to the number of determinations, the time slot selection unit 54 selects the transmission time slot 56 according to a second rule.

[0091] The second aspect of the present invention is a communication method for a remote wireless device 18, which transmits and receives signals with a base wireless device 16 in a transmit-receive cycle. The communication method of the remote wireless device includes: a transmit-receive processing step, which performs signal transmission processing in each of a plurality of consecutive transmit-receive cycles until transmission to the base wireless device 16 is successful; a counting step, which counts the number of times the transmission processing is performed; a transmission selection step, which, if the count value N in the counting step is greater than or equal to a predetermined number of times, selects whether to perform the transmission processing or to standby in the next transmit-receive cycle according to a predetermined rule; and a transmission prohibition step, which prohibits the transmission processing if standby is selected in the transmission selection step.

[0092] In a second aspect of the present invention, a time slot selection step may be included, in which a transmission time slot 56 is selected from a plurality of transmission time slots 56 that are set in each of the transmission and reception cycles and have different start times for the transmission process, and the transmission process is performed in the transmission and reception process using the transmission time slot 56 selected in the time slot selection step.

[0093] In a second aspect of the present invention, the transmitting and receiving process may include, as part of the transmitting process, idle channel assessment, signal transmission, and reception of acknowledgment responses sent from the basic wireless device 16. If the channel is detected to be in use through the idle channel assessment, or if the acknowledgment response is not received, the transmission is determined to have failed.

[0094] In a second aspect of the present invention, in the time slot selection step, if the count value N is less than a predetermined number of determinations, the transmission time slot 56 is selected according to a first rule; if the count value N is greater than or equal to the number of determinations, the transmission time slot 56 is selected according to a second rule.

Claims

1. A remote wireless device, which transmits and receives signals with a basic wireless device at a transmit-receive cycle, characterized in that, have: A transceiver processing unit performs signal transmission processing in each of the multiple consecutive transceiver cycles until the transmission to the basic wireless device is successful. A counting unit that counts the number of retries performed on the transmission process across multiple consecutive transmit / receive cycles; The transmission selection unit compares the count value of the number of retries performed by the counting unit with a predetermined number. If it is determined that the count value is greater than the predetermined number, the transmission selection unit selects whether to perform the transmission process or standby in the next transmission cycle according to a predetermined rule. as well as The transmission inhibit unit, when it selects to put the transmission process into standby mode in the next transmit / receive cycle, prohibits the transmission process. If the transmission selection unit selects to perform the transmission process in the next transmission cycle, the transmission processing unit performs the transmission process.

2. The remote wireless device according to claim 1, characterized in that, The device includes a time slot selection unit that selects one of multiple transmission time slots that are set in each of the transmit / receive cycles and have different start times for the transmission process. The transceiver processing unit uses the transmission time slot selected by the time slot selection unit to perform the transmission processing.

3. The remote wireless device according to claim 2, characterized in that, As part of the transmission process, the transceiver processing unit performs idle channel assessment, transmits signals, and receives acknowledgment responses sent from the basic wireless device. If the idle channel assessment detects that the channel is in use, or if no acknowledgment response is received, the transmission is deemed to have failed.

4. The remote wireless device according to claim 2, characterized in that, If the count value is less than the predetermined number of determinations, the time slot selection unit selects the transmission time slot according to a first rule; if the count value is greater than the predetermined number of determinations, the time slot selection unit selects the transmission time slot according to a second rule.

5. A communication method for a remote wireless device, wherein the remote wireless device transmits and receives signals with a basic wireless device at a transmit-receive cycle, the communication method of the remote wireless device being characterized by comprising: The transmit / receive processing step performs signal transmission processing in each of the multiple consecutive transmit / receive cycles until the transmission to the basic wireless device is successful. The counting step counts the number of retries performed on the transmission process across multiple consecutive transmission and reception cycles. In the sending selection step, the count value of the number of retries in the counting step is compared with a predetermined number. If it is determined that the count value is greater than the predetermined number, a selection is made according to the predetermined rules to whether to perform the sending process or standby in the next sending and receiving cycle. as well as The transmit prohibition step prohibits the transmit processing if the transmit processing is selected to be put into standby mode in the next transmit / receive cycle. If, in the transmission selection step, the transmission process is selected to be performed in the next transmission cycle, then the transmission process is performed in the transmission process step.

6. The communication method of the remote wireless device according to claim 5, characterized in that, The system includes a time slot selection step, which selects one of multiple transmission time slots that are set within each of the said transmit / receive cycles and have different start times for the transmission process. In the transmit / receive processing step, the transmit processing is performed using the transmit time slot selected in the time slot selection step.

7. The communication method of the remote wireless device according to claim 6, characterized in that, In the transmit / receive processing steps, as part of the transmit processing, idle channel assessment, signal transmission, and reception of acknowledgment responses sent from the basic wireless device are performed. If the channel is detected to be in use through the idle channel assessment, or if the acknowledgment response is not received, the transmit is determined to have failed.

8. The communication method of the remote wireless device according to claim 6, characterized in that, In the time slot selection step, if the count value is less than the predetermined number of determinations, the transmission time slot is selected according to the first rule; if the count value is greater than the predetermined number of determinations, the transmission time slot is selected according to the second rule.

Images