Pattern generation device, pattern generation method, and wireless communication system

Abstract

To provide a device that when many communication networks for communicating using a frequency hopping method exist in the same area, reduces possibility of collision between their radio waves.SOLUTION: An industrial radio communication system 10 comprises a communications network 14 including a pattern generation device 24 comprising: a random number generation unit that takes a unique number given to a base radio device 18 as a seed to generate a plurality of random numbers; an association unit for associating different random numbers with frequencies of respective channels; and a pattern generation unit that on the basis of numerical values represented by the respective random numbers, determines order of the plurality of random numbers and arranges frequencies corresponding to the random numbers in the same order as that of the random numbers to generate a change pattern.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pattern generation device that generates a frequency change pattern, a pattern generation method that generates a frequency change pattern, and a wireless communication system that performs two-way communication using a frequency hopping method. [Background technology]

[0002] Patent Document 1 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. The base wireless device and the remote wireless devices communicate bidirectionally using a frequency hopping method. Patent Document 1 discloses a specific calculation formula for generating a frequency change pattern. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-188868 Summary of the Invention [Problem to be solved by the invention]

[0004] When there are many communication networks that communicate using frequency hopping within the same area, it is preferable for each communication network to use a different hopping pattern to avoid collision of radio waves. However, the hopping patterns generated by the calculation formula in Patent Document 1 are only a few to several tens of patterns. When the number of communication networks is small, the possibility of radio wave collision is low even with a few to several tens of hopping patterns. However, when the number of communication networks increases, the possibility of radio wave collision increases.

[0005] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] A first aspect of the present invention is a pattern generation device that generates a frequency change pattern used in a wireless communication system in which a base radio device and at least one remote radio device communicate while changing frequencies, and includes a random number generation unit that generates a plurality of random numbers using a unique number assigned to the base radio device as a seed, a matching unit that matches different random numbers to the frequencies of each channel, and a pattern generation unit that determines the order of the plurality of random numbers based on the numerical value represented by each of the random numbers, and generates the change pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers.

[0007] A second aspect of the present invention is a pattern generation method for generating a frequency change pattern used in a wireless communication system in which a base radio device and at least one remote radio device communicate while changing frequencies, comprising: a random number generation step for generating a plurality of random numbers using a unique number assigned to the base radio device as a seed; an association step for associating different random numbers with the frequencies of each channel; and a pattern generation step for determining the order of the plurality of random numbers based on the numerical value represented by each of the random numbers, and generating the change pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers.

[0008] A third aspect of the present invention is a wireless communication system in which a base radio device and at least one remote radio device communicate while changing frequencies, comprising: a random number generation unit that generates a plurality of random numbers using a unique number assigned to the base radio device as a seed; a correspondence unit that associates different random numbers with the frequencies of each channel; a pattern generation unit that determines the order of the plurality of random numbers based on the numerical value represented by each of the random numbers and generates a frequency change pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers; a base frequency change unit that changes the frequency of radio waves used in communication from the base radio device to the remote radio device based on the change pattern; and a remote frequency change unit that changes the frequency of radio waves used in communication from the remote radio device to the base radio device based on the change pattern. [Effects of the Invention]

[0009] According to the present invention, collision of radio waves between a plurality of communication networks that communicate using frequency hopping is less likely to occur. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a wireless communication system. [Figure 2] FIG. 1 is a diagram illustrating functional blocks of a communication network. [Figure 3] 10 is a flowchart showing a change pattern generation process. [Figure 4] FIG. 10 is a diagram illustrating an example of a process for generating random numbers. [Figure 5] FIG. 4 is a diagram illustrating a process of frequency alignment processing in the first embodiment. [Figure 6] FIG. 10 is a diagram illustrating a process of frequency alignment processing in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] [1 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 a communication network 14. The industrial wireless communication system 10 includes one computer 12, at least one communication network 14, and a pattern generation device 24. One communication network 14 includes one base wireless device 18 and multiple remote wireless devices 20. The base wireless device 18 and the remote wireless devices 20 perform bidirectional communication while changing their frequencies. The industrial facility is equipped with one or more robots, etc. (not shown).

[0012] 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 a wire. The computer 12 transmits signals to the base radio device 18 via the interface. The computer 12 also receives signals transmitted from the base radio device 18 via the interface.

[0013] 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 22. The actuators receive control signals transmitted from the computer 12 via the base radio device 18 and the remote radio device 20. The sensors transmit sensor signals indicating the detection results to the computer 12 via the base radio device 18 and the remote radio device 20.

[0014] The pattern generation device 24 generates a frequency change pattern 88 (FIGS. 5 and 6) for changing frequencies in the base radio device 18 and the remote radio device 20. The change pattern 88 has a plurality of synchronization frequencies or a plurality of carrier frequencies (hopping frequencies). The synchronization frequency is a radio wave frequency used when the base radio device 18 and the remote radio device 20 perform synchronization processing. The carrier frequency is a radio wave frequency used when the base radio device 18 and the remote radio device 20 perform bidirectional communication using a frequency hopping method. In the wireless communication system 10, the base radio device 18 and the remote radio device 20 function as the pattern generation device 24. However, either the base radio device 18 or the remote radio device 20 may function as the pattern generation device 24. Alternatively, an independent device such as a personal computer may function as the pattern generation device 24. When the base radio device 18 does not function as the pattern generation device 24, the base radio device 18 acquires the change pattern 88 from the pattern generation device 24. Similarly, if the remote radio device 20 does not function as the pattern generator 24 , the remote radio device 20 obtains the modified pattern 88 from the pattern generator 24 .

[0015] [2 Base Radio Device 18 (Pattern Generator 24)] 2, the base radio device 18 includes a base calculation unit 30, a base storage unit 32, a base communication unit 34, and a base interface 36. As described above, the base radio device 18 functions as the pattern generation device 24.

[0016] The base calculation unit 30 has a processing circuit. The processing circuit has a processor such as a CPU. The processing circuit may also have an integrated circuit such as an ASIC or FPGA. For example, the processor has various functions by executing programs stored in the base storage unit 32. In this embodiment, the base calculation unit 30 functions as a base frequency changer 38, a base transmission / reception processor 40, a base input / output controller 42, a random number generator 44, an association unit 46, and a pattern generator 48.

[0017] The base frequency changer 38 switches the frequency of the channel used by the base communication unit 34 based on the change pattern 88 generated by the pattern generator 48 .

[0018] The base transmission / reception processing unit 40 uses the transmission circuit of the base communication unit 34 to perform processing for transmitting signals to the remote radio device 20. In addition, the base transmission / reception processing unit 40 uses the reception circuit of the base communication unit 34 to perform processing for receiving signals transmitted by the remote radio device 20.

[0019] The base input / output control unit 42 uses the base interface 36 to perform a process of transmitting signals to other devices. The base input / output control unit 42 also uses the base interface 36 to perform a process of receiving signals from other devices. The transmission / reception process performed by the base input / output control unit 42 differs from the transmission / reception process performed by the base transmission / reception processing unit 40. The base input / output control unit 42 may also use the base interface 36 to perform a process of writing data to a storage medium removable from the base radio device 18. The base input / output control unit 42 may also use the base interface 36 to perform a process of reading data from a storage medium removable from the base radio device 18.

[0020] The random number generation unit 44 obtains a unique number (PID) assigned to the base radio device 18 from the base storage unit 32 or an input device (not shown). The random number generation unit 44 generates a plurality of random numbers using the PID as a seed 70 (FIG. 4).

[0021] The association unit 46 associates different random numbers with the frequencies of available channels. The association unit 46 acquires information on available channels from the base storage unit 32 or an external device (not shown).

[0022] The pattern generating unit 48 determines the order of the random numbers based on the numerical values represented by the random numbers. The pattern generating unit 48 generates a change pattern 88 by arranging the frequencies corresponding to the random numbers in the same order as the random numbers.

[0023] The base storage unit 32 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, for example, data acquired from the outside and data calculated by the base calculation unit 30. The non-volatile memory stores, for example, predetermined programs and predetermined numerical values. The base storage unit 32 stores the change pattern 88 generated by the pattern generation unit 48. At least a part of the base storage unit 32 may be provided in the processor, integrated circuit, etc. described above.

[0024] The base communication unit 34 has a communication circuit. The communication circuit includes a transmitting circuit and a receiving circuit. The base communication unit 34 transmits signals to the remote radio device 20. The base communication unit 34 also receives signals transmitted by the remote radio device 20.

[0025] The base interface 36 has an interface that allows the base radio device 18 to input and output data from and to other devices. For example, the base interface 36 may have a wired interface that allows the base radio device 18 to communicate with other devices via wires. The base interface 36 may have a wireless interface that allows the base radio device 18 to communicate with other devices via short-range wireless communication. The base interface 36 may have an interface that allows data to be written to a storage medium that is detachable from the base radio device 18. The base interface 36 may also have an interface that allows data to be read from a storage medium that is detachable from the base radio device 18.

[0026] [3 Remote Radio Device 20 (Pattern Generator 24)] 2, the remote radio device 20 includes a remote computing unit 50, a remote storage unit 52, a remote communication unit 54, and a remote interface 56. As described above, the remote radio device 20 functions as the pattern generating device 24.

[0027] The remote calculation unit 50 has a processing circuit. The processing circuit has a processor such as a CPU. The processing circuit may also have an integrated circuit such as an ASIC or FPGA. For example, the processor has various functions by executing programs stored in the remote storage unit 52. In this embodiment, the remote calculation unit 50 functions as a remote frequency changer 58, a remote transmission / reception processor 60, a remote input / output controller 62, a random number generator 64, an association unit 66, and a pattern generator 68.

[0028] The remote frequency changer 58 switches the frequency of the channel used by the remote communication unit 54 based on the change pattern 88 generated by the pattern generator 68 .

[0029] The remote transmission / reception processing unit 60 uses the transmission circuit of the remote communication unit 54 to perform processing for transmitting signals to the base radio device 18. The remote transmission / reception processing unit 60 also uses the reception circuit of the remote communication unit 54 to perform processing for receiving signals transmitted by the base radio device 18.

[0030] The remote input / output control unit 62 performs a process of transmitting signals to other devices using the remote interface 56. The remote input / output control unit 62 also performs a process of receiving signals from other devices using the remote interface 56. The transmission / reception process performed by the remote input / output control unit 62 differs from the transmission / reception process performed by the remote transmission / reception processing unit 60. The remote input / output control unit 62 may also perform a process of writing data to a storage medium removable from the remote wireless device 20 using the remote interface 56. The remote input / output control unit 62 may also perform a process of reading data from a storage medium removable from the remote wireless device 20 using the remote interface 56.

[0031] The random number generation unit 64 obtains a unique number (PID) assigned to the base radio device 18 from the remote storage unit 52 or an input device (not shown). The random number generation unit 64 generates multiple random numbers using the PID as a seed 70. The random number generation unit 64 performs the same processing as the random number generation unit 44 of the base radio device 18. Therefore, the random number generation unit 64 generates the same random numbers as those generated by the random number generation unit 44.

[0032] The association unit 66 associates different random numbers with the frequencies of available channels. The association unit 66 obtains information on available channels from the remote storage unit 52 or an external device (not shown).

[0033] The pattern generation unit 68 determines the order of the multiple random numbers based on the numerical values represented by the random numbers. The pattern generation unit 68 generates a change pattern 88 by arranging the frequencies corresponding to the random numbers in the same order as the random numbers. The pattern generation unit 68 performs the same processing as the pattern generation unit 48 of the base radio device 18. Therefore, the pattern generation unit 68 generates a change pattern 88 that is the same as the change pattern 88 generated by the pattern generation unit 48.

[0034] The remote storage unit 52 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, for example, data acquired from the outside and data calculated by the remote calculation unit 50. The non-volatile memory stores, for example, predetermined programs and predetermined numerical values. The remote storage unit 52 stores the change pattern 88 generated by the pattern generation unit 68. At least a part of the remote storage unit 52 may be provided in the processor, integrated circuit, etc. as described above.

[0035] The remote communication unit 54 has a communication circuit. The communication circuit includes a transmitting circuit and a receiving circuit. The remote communication unit 54 transmits signals to the base radio device 18. The remote communication unit 54 also receives signals transmitted by the base radio device 18.

[0036] The remote interface 56 has an interface through which the remote wireless device 20 inputs and outputs data to and from other devices. For example, the remote interface 56 may have a wired interface through which the remote wireless device 20 performs wired communication with other devices. The remote interface 56 may have a wireless interface through which the remote wireless device 20 performs short-range wireless communication with other devices. The remote interface 56 may have an interface through which data is written to a storage medium detachable from the remote wireless device 20. The remote interface 56 may also have an interface through which data is read from a storage medium detachable from the remote wireless device 20.

[0037] [4. Change pattern generation process] The change pattern generation process executed by the pattern generation units 48, 68 will be described with reference to Figures 3 to 6. Figure 3 is a flowchart showing the change pattern generation process. The process shown in Figures 3 to 6 is performed by the base radio device 18 functioning as the pattern generation device 24. The process shown in Figures 3 to 6 is also performed by the remote radio device 20 functioning as the pattern generation device 24.

[0038] [4-1 First Embodiment] The change pattern generation process of the first embodiment will be described with reference to FIGS.

[0039] In step S1, the pattern generation device 24 performs a random number generation process. The random number generation process of the first embodiment is described below in [4-1-1]. In step S2, the pattern generation device 24 performs a frequency alignment process. The frequency alignment process of the first embodiment is described below in [4-1-2]. In step S2, a change pattern 88 is generated.

[0040] [4-1-1 Random number generation process] Fig. 4 is a diagram showing an example of the process of random number generation processing. The random number generation processing shown in Fig. 4 is performed by random number generation unit 44. Note that the random number generation processing shown in Fig. 4 is also performed by random number generation unit 64.

[0041] In step S1 of Fig. 3, the random number generation unit 44 generates pseudo-random numbers by executing a predetermined algorithm. In this specification, pseudo-random numbers are simply referred to as random numbers. For example, the random number generation unit 44 generates random numbers by Xorshift as shown in the following algorithm. X=SEED X 1 =X^(X<<13); X 2 =X 1 ^(X 1 >>17); X 3 =X 2 ^(X 2 <<15); ReturnX;

[0042] In the example shown in Fig. 4, the random number generation unit 44 sets a PID, which is an eight-digit number "12224001", as the seed 70. S11 to S20 shown in Fig. 4 correspond to the processes of steps S11 to S20 described below.

[0043] In step S11, the random number generation unit 44 divides the PID into four groups 72. Each group 72 includes a two-digit number.

[0044] In step S12, the random number generation unit 44 regards the two-digit numerical value included in each group 72 as a hexadecimal number. The random number generation unit 44 converts the hexadecimal number into an 8-bit binary number. The random number generation unit 44 generates a series of bit patterns by connecting the binary numbers of the four groups 72. This bit pattern is referred to as a first bit pattern 74. The first bit pattern 74 includes a 32-bit numerical value from bit 0 to bit 31.

[0045] In step S13, the random number generation unit 44 logically shifts the first bit pattern 74 to the left by 13 bits. As part of this process, the random number generation unit 44 discards the values in each of the 19th to 31st bit positions of the first bit pattern 74. The random number generation unit 44 also inserts 0 into each of the 0th to 12th bit positions. The bit pattern after the shift is referred to as a first shift pattern 76.

[0046] In step S14, the random number generation unit 44 adds the numerical values at multiple bit positions in the first bit pattern 74 to the numerical values at multiple bit positions in the first shift pattern 76. Specifically, the random number generation unit 44 adds the numerical values at the same bit position. The random number generation unit 44 discards the numerical value of the carried-over digit. The bit pattern after the addition is referred to as a second bit pattern 78.

[0047] In step S15, the random number generation unit 44 logically shifts the second bit pattern 78 to the right by 17 bits. As part of this process, the random number generation unit 44 discards the values that were in each of the bit positions 0 through 16 of the second bit pattern 78. The random number generation unit 44 also inserts 0 into each of the bit positions 15 through 31. The bit pattern after the shift is referred to as a second shift pattern 80.

[0048] In step S16, the random number generation unit 44 adds the numerical value at each bit position of the second bit pattern 78 to the numerical value at each bit position of the second shift pattern 80. Specifically, the random number generation unit 44 adds numerical values at the same bit position. The random number generation unit 44 discards the numerical value of the carried-over digit. The bit pattern after the addition is referred to as a third bit pattern 82.

[0049] In step S17, the random number generation unit 44 logically shifts the third bit pattern 82 to the left by 15 bits. As part of this process, the random number generation unit 44 discards the values that were in each of the 17th to 31st bit positions of the third bit pattern 82. The random number generation unit 44 also inserts 0 into each of the 0th to 14th bit positions. The bit pattern after the shift is referred to as a third shift pattern 84.

[0050] In step S18, the random number generation unit 44 adds the numerical value at each bit position of the third bit pattern 82 to the numerical value at each bit position of the third shift pattern 84. Specifically, the random number generation unit 44 adds numerical values at the same bit position. The random number generation unit 44 discards the numerical value of the carried-over digit. The bit pattern after the addition is referred to as a fourth bit pattern 86.

[0051] In step S19, the random number generation unit 44 divides the 32-bit fourth bit pattern 86 into four groups 72. Each group 72 includes an 8-bit binary number. Furthermore, the random number generation unit 44 converts the binary numbers of the four groups 72 into hexadecimal numbers.

[0052] In step S20, the random number generation unit 44 generates a random number by concatenating two-digit hexadecimal numbers of the four groups 72. In the example shown in Fig. 4, the random number is an eight-digit number "7CAA4D10".

[0053] As described above, the random number generation unit 44 can generate one random number by performing the processes from step S11 to step S20 once using the PID as the seed 70. The random number generation unit 44 can also generate a new random number by performing the processes from step S11 to step S20 once using the random number generated in step S20 as a new seed 70. In this way, the random number generation unit 44 can generate multiple random numbers by changing the number of times the processes from step S11 to step S20 are performed.

[0054] The above algorithm is an example, and the random number generation process performed by the random number generation unit 44 is not limited to this. The random number generation unit 44 may generate random numbers using other methods.

[0055] [4-1-2 Frequency Alignment Processing] The ISM band includes the band from 2403 to 2481 MHz. frequency Centered on the 2403 [MHz] channel frequency The frequency band includes 79 channels with frequencies from 1 to 2481 MHz. An interval of 1 MHz is set between the center frequency of each channel and the center frequency of an adjacent channel. The pattern generator 24 generates a modified pattern 88 by performing the following frequency alignment process. The modified pattern 88 has the center frequencies of each of the multiple channels.

[0056] Fig. 5 is a diagram showing the process of frequency alignment processing in the first embodiment. The frequency alignment processing shown in Fig. 5 is performed by the association unit 46 and the pattern generation unit 48. Note that the frequency alignment processing shown in Fig. 5 is also performed by the association unit 66 and the pattern generation unit 68.

[0057] 3, the association unit 46 and the pattern generation unit 48 execute the following algorithm to generate a change pattern 88. Steps S21 to S24 shown in FIG. 5 correspond to the processes of steps S21 to S24 described below.

[0058] In step S21, the association unit 46 divides the frequencies included in the band of 2403 to 2481 [MHz] into three groups. Group A includes frequencies from 2403 to 2429 [MHz]. Group B includes frequencies from 2430 to 2455 [MHz]. Group C includes frequencies from 2456 to 2481 [MHz]. Note that the association unit 46 may divide the frequencies into a number of groups other than three. The association unit 46 equalizes the number of frequencies included in each group. If the numbers of frequencies are not equal, the number of frequencies increases in the order of group A, group B.

[0059] Furthermore, the association unit 46 associates a different random number generated by the random number generation unit 44 with each frequency of the 79 channels. Note that each frequency shown in Fig. 5 is associated with the decimal value of a random number generated using "12224001" shown in Fig. 4 as the seed 70. Specifically, 2403+N (N=a natural number from 0 to 78) [MHz] is associated with the decimal value of a random number generated by performing the random number generation process 10+N times.

[0060] In step S22, the pattern generation unit 48 determines the order of the multiple random numbers in each of the three groups based on the numerical value represented by each random number. The pattern generation unit 48 regards a random number, which is a string of n numbers, as an n-digit numerical value. The pattern generation unit 48 determines the order of each random number when the numerical values represented by the multiple random numbers are arranged in ascending order in each of the three groups. Note that the pattern generation unit 48 may arrange the numerical values represented by the multiple random numbers in descending order instead of ascending order.

[0061] In step S23, the pattern generation unit 48 selects the smallest random number in each group. In group A shown in FIG. 5, "340240664" is the smallest. The pattern generation unit 48 selects 2422 [MHz] corresponding to "340240664" from group A. In group B shown in FIG. 5, "277256148" is the smallest. The pattern generation unit 48 selects 2431 [MHz] corresponding to "277256148" from group B. In group C shown in FIG. 5, "10933374" is the smallest. The pattern generation unit 48 selects 2466 [MHz] corresponding to "10933374" from group C. Note that the pattern generation unit 48 may select the largest random number in each group. Alternatively, the pattern generation unit 48 may select random numbers of other ranks.

[0062] In step S24, the pattern generation unit 48 arranges the selected random numbers in ascending order. Furthermore, the pattern generation unit 48 arranges the frequencies corresponding to the random numbers in the same order as the random numbers. The pattern generation unit 48 sets the arrangement of the frequencies as a change pattern 88.

[0063] [4-2 Second embodiment] The change pattern generation process of the second embodiment will be described using Figures 3, 4, and 6. As in the first embodiment, the change pattern generation process shown in Figure 3 is performed in the second embodiment. Also, the random number generation process shown in Figure 4 is performed in the second embodiment. Also, the frequency alignment process shown in Figure 6 is performed in the second embodiment. Of the processes in the second embodiment, descriptions of the same processes as in the first embodiment will be omitted.

[0064] Fig. 6 is a diagram showing the process of frequency alignment processing in the second embodiment. The frequency alignment processing shown in Fig. 6 is performed by the association unit 46 and the pattern generation unit 48. Note that the frequency alignment processing shown in Fig. 6 is also performed by the association unit 66 and the pattern generation unit 68.

[0065] 3, the association unit 46 and the pattern generation unit 48 execute the following algorithm to generate the change pattern 88. S31 to S33 shown in FIG. 6 correspond to the processes of steps S31 to S33 described below.

[0066] In step S31, the association unit 46 divides the frequencies included in the band of 2403 to 2481 [MHz] into two groups. Group A includes frequencies from 2403 to 2442 [MHz]. Group B includes frequencies from 2443 to 2481 [MHz]. The association unit 46 equalizes the number of frequencies included in each group. If the numbers of frequencies are not equal, the number of frequencies in group A is increased.

[0067] Furthermore, the association unit 46 associates a different random number generated by the random number generation unit 64 with each frequency of the 79 channels. Note that each frequency shown in Fig. 6 is associated with the decimal value of a random number generated using "12224001" shown in Fig. 4 as the seed 70. Specifically, 2403+N (N=a natural number from 0 to 78) [MHz] is associated with the decimal value of a random number generated by performing the random number generation process 10+N times.

[0068] In step S32, the pattern generation unit 48 determines the order of the multiple random numbers in each of the two groups based on the numerical value represented by each random number. The pattern generation unit 48 regards a random number, which is a string of n numbers, as an n-digit numerical value. The pattern generation unit 48 determines the order of each random number when the numerical values represented by the multiple random numbers are arranged in ascending order in each of the two groups. Note that the pattern generation unit 48 may also determine the order of each random number when the numerical values represented by the multiple random numbers are arranged in descending order.

[0069] In step S33, the pattern generation unit 48 alternately selects random numbers one by one from the two groups in the same order as the random numbers. Specifically, the pattern generation unit 48 alternately repeats the process of selecting the smallest random number from group A and the process of selecting the smallest random number from group B. Note that the pattern generation unit 48 may alternately repeat the process of selecting the largest random number from group A and the process of selecting the largest random number from group B. The pattern generation unit 48 arranges the random numbers in the order in which they were selected. Furthermore, the pattern generation unit 48 arranges the frequencies corresponding to the random numbers in the same order as the random numbers. The pattern generation unit 48 sets the arrangement of the frequencies as a change pattern 88.

[0070] In the first and second embodiments, the pattern generation units 48, 68 generate a change pattern 88 based on a random number using the PID of the base radio device 18 as a seed 70. The PID is a unique number assigned to each base radio device 18. In other words, the pattern generation units 48, 68 can generate a unique random number for each base radio device 18. Therefore, even if the number of communication networks 14 increases, each communication network 14 can perform two-way communication using its own unique change pattern 88. This reduces the possibility of radio waves from multiple communication networks 14 colliding.

[0071] The pattern generation device 24 may generate the change pattern 88 using a radio wave frequency that is not used in the area where the wireless communication system 10 is installed. In this case, a frequency measurement device (not shown) may measure the frequency of the radio wave in the area where the wireless communication system 10 is installed and provide the measurement result to the pattern generation device 24.

[0072] [5. Wireless Communication Between Base Radio Device 18 and Remote Radio Device 20] The base radio device 18 and the remote radio device 20 initially share the same change pattern 88. For example, when the base radio device 18 and the remote radio device 20 are paired, the base radio device 18 transmits a PID to the remote radio device 20. This allows the base radio device 18 and the remote radio device 20 to perform random number generation processing using the same PID as the seed 70. As a result, the base radio device 18 and the remote radio device 20 can generate the same change pattern 88. Note that the base radio device 18 may generate the change pattern 88 and transmit it to the remote radio device 20 at the time of pairing. Alternatively, a pattern generation device 24 independent of the base radio device 18 and the remote radio device 20 may generate the change pattern 88 and transmit it to the base radio device 18.

[0073] The base radio device 18 and the remote radio device 20 perform synchronization processing before performing two-way communication. As the synchronization processing, the base radio device 18 performs processing to transmit a synchronization signal to the multiple remote radio devices 20 by broadcasting. The synchronization signal includes information (time data, etc.) necessary for synchronization between the base radio device 18 and the remote radio device 20. As described above, the frequency of the radio waves used when transmitting the synchronization signal is called the synchronization frequency.

[0074] The base frequency changer 38 and the remote frequency changer 58 change the synchronization frequency based on the change pattern 88 generated in the first embodiment. The base frequency changer 38 switches the synchronization frequency at every first time interval T1. The remote frequency changer 58 switches the synchronization frequency at every second time interval T2. The base transmission / reception processor 40 performs processing to transmit a synchronization signal using radio waves at the synchronization frequency. On the other hand, the remote transmission / reception processor 60 performs processing to receive radio waves at the synchronization frequency. When the synchronization frequency of the base radio device 18 and the synchronization frequency of the remote radio device 20 match, the remote radio device 20 can receive the synchronization signal transmitted by the base radio device 18.

[0075] After the synchronization process, the base frequency changer 38 and the remote frequency changer 58 change the carrier frequency based on the change pattern 88 generated in the second embodiment. The base frequency changer 38 and the remote frequency changer 58 switch the carrier frequency at the same time interval T3. The base transmission / reception processor 40 performs processing to transmit and receive radio waves of the carrier frequency. Similarly, the remote transmission / reception processor 60 performs processing to transmit and receive radio waves of the carrier frequency. In this way, the base radio device 18 and the remote radio device 20 perform bidirectional communication using the frequency hopping method.

[0076] In the second embodiment, the association unit 46 divides a predetermined frequency band (ISM band) into two groups with an intermediate frequency as the boundary. Furthermore, the pattern generation unit 48 alternately selects frequencies from the two groups to generate the change pattern 88. According to this embodiment, when the base radio device 18 and the remote radio device 20 perform bidirectional communication, collision of radio waves with the change pattern 88 used by another network is less likely to occur.

[0077] [6 Technical ideas obtained from the embodiments] The technical ideas that can be understood from the above-described embodiments will be described below.

[0078] A first aspect of the present invention is a pattern generation device 24 that generates a frequency change pattern 88 used in a wireless communication system 10 in which a base radio device 18 and at least one remote radio device 20 communicate while changing frequencies, and includes a random number generation unit 44, 64 that generates a plurality of random numbers using a unique number assigned to the base radio device 18 as a seed 70, an association unit 46, 66 that associates different random numbers with the frequencies of each channel, and a pattern generation unit 48, 68 that determines the order of the plurality of random numbers based on the numerical value represented by each random number and generates the change pattern 88 by arranging the frequencies corresponding to the random numbers in the same order as the random numbers.

[0079] In a first aspect of the present invention, the association unit 46, 66 divides the multiple random numbers and the multiple frequencies into multiple groups, and the pattern generation unit 48, 68 determines the order of the multiple random numbers within each group based on the numerical value represented by each of the random numbers, selects random numbers of a predetermined order from each of the groups, determines the order of the selected multiple random numbers based on the numerical value represented by each of the selected random numbers, and generates the change pattern 88 by arranging the frequencies corresponding to the random numbers in the same order as the random numbers.

[0080] In a first aspect of the present invention, the association unit 46, 66 divides the multiple random numbers and the multiple frequencies into two groups, and the pattern generation unit 48, 68 determines the order of the multiple random numbers within the two groups based on the numerical value represented by each of the random numbers, alternately performs a process of selecting random numbers one by one from the two groups in the same order as the random numbers, and generates the change pattern 88 by arranging the random numbers in the selected order.

[0081] A second aspect of the present invention is a pattern generation method for generating a frequency change pattern 88 used in a wireless communication system 10 in which a base radio device 18 and at least one remote radio device 20 communicate while changing frequencies, and includes a random number generation step for generating a plurality of random numbers using a unique number assigned to the base radio device 18 as a seed 70, an association step for associating different random numbers with the frequencies of each channel, and a pattern generation step for determining the order of the plurality of random numbers based on the numerical value represented by each of the random numbers, and generating the change pattern 88 by arranging the frequencies corresponding to the random numbers in the same order as the random numbers.

[0082] A third aspect of the present invention is a wireless communication system 10 in which a base radio device 18 and at least one remote radio device 20 communicate while changing frequencies, and includes a random number generation unit 44, 64 that generates a plurality of random numbers using a unique number assigned to the base radio device 18 as a seed 70, an association unit 46, 66 that associates different random numbers with the frequencies of each channel, a pattern generation unit 48, 68 that determines the order of the plurality of random numbers based on the numerical value represented by each of the random numbers and generates a frequency change pattern 88 by arranging the frequencies corresponding to the random numbers in the same order as the random numbers, a base frequency change unit 38 that changes the frequency of radio waves used in communication from the base radio device 18 to the remote radio device 20 based on the change pattern 88, and a remote frequency change unit 58 that changes the frequency of radio waves used in communication from the remote radio device 20 to the base radio device 18 based on the change pattern 88. [Explanation of symbols]

[0083] 10... Wireless communication system 18... Base radio device 20...Remote radio device 24...Pattern generating device 38... Base frequency change unit 44, 64... Random number generation unit 46, 66... Corresponding section 48, 68... Pattern generating section 58...Remote frequency change section 70...Type 88...Change pattern

Claims

1. 1. A pattern generator for generating a frequency change pattern used in a wireless communication system in which a base wireless device and at least one remote wireless device communicate with each other while changing the frequency, comprising: a random number generator that generates a plurality of random numbers using a unique number assigned to the base radio device as a seed; an association unit that associates different random numbers with the frequencies of the respective channels; a pattern generating unit that determines the order of the random numbers based on the numerical value represented by each of the random numbers, and generates the change pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers; Equipped with The association unit Dividing the random numbers and the frequencies into a plurality of groups; The pattern generation unit determining an order of the random numbers within each of the groups based on the numerical value represented by each of the random numbers; selecting the random numbers in a predetermined order from each of the groups; A pattern generating device that determines the order of the selected random numbers based on the numerical value represented by each selected random number, and generates the modified pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers.

2. A pattern generating device for generating a frequency change pattern used in a wireless communication system in which a base wireless device and at least one remote wireless device communicate while changing the frequency, comprising: a random number generator that generates a plurality of random numbers using a unique number assigned to the base radio device as a seed; an association unit that associates different random numbers with the frequencies of the respective channels; a pattern generating unit that determines the order of the random numbers based on the numerical value represented by each of the random numbers, and generates the change pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers; Equipped with The association unit Dividing the plurality of random numbers and the plurality of frequencies into two groups; The pattern generation unit determining an order of the random numbers within the two groups based on the numerical value represented by each of the random numbers; A pattern generating device that alternately selects random numbers one by one from the two groups in the same order as the random numbers, and generates the change pattern by arranging the random numbers in the selected order.

3. 1. A pattern generation method for generating a frequency change pattern used in a wireless communication system in which a base wireless device and at least one remote wireless device communicate while changing the frequency, comprising: a random number generation step of generating a plurality of random numbers using a unique number assigned to the base radio device as a seed; a correspondence step of associating different random numbers with the frequencies of the respective channels; a pattern generating step of determining the order of the random numbers based on the numerical value represented by each of the random numbers, and generating the modified pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers; Equipped with In the association step, Dividing the random numbers and the frequencies into a plurality of groups; In the pattern generating step, determining an order of the random numbers within each of the groups based on the numerical value represented by each of the random numbers; selecting the random numbers in a predetermined order from each of the groups; A pattern generation method that determines the order of multiple selected random numbers based on the numerical value represented by each selected random number, and generates the modified pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers.

4. A pattern generation method for generating a frequency change pattern used in a wireless communication system in which a base wireless device and at least one remote wireless device communicate while changing the frequency, comprising: a random number generation step of generating a plurality of random numbers using a unique number assigned to the base radio device as a seed; a correspondence step of associating different random numbers with the frequencies of the respective channels; a pattern generating step of determining the order of the random numbers based on the numerical value represented by each of the random numbers, and generating the modified pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers; Equipped with In the association step, Dividing the plurality of random numbers and the plurality of frequencies into two groups; In the pattern generating step, determining an order of the random numbers within the two groups based on the numerical value represented by each of the random numbers; A pattern generation method that alternately selects random numbers one by one from the two groups in the same order as the random numbers, and generates the change pattern by arranging the random numbers in the selected order.

5. A wireless communication system in which a base wireless device and at least one remote wireless device communicate with each other while changing frequencies, a random number generator that generates a plurality of random numbers using a unique number assigned to the base radio device as a seed; an association unit that associates different random numbers with the frequencies of the respective channels; a pattern generating unit that determines the order of the random numbers based on the numerical value represented by each of the random numbers, and generates a frequency change pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers; a base frequency changing unit that changes the frequency of radio waves used in communication from the base radio device to the remote radio device based on the change pattern; a remote frequency change unit that changes the frequency of radio waves used in communication from the remote radio device to the base radio device based on the change pattern; Equipped with The association unit Dividing the random numbers and the frequencies into a plurality of groups; The pattern generation unit determining an order of the random numbers within each of the groups based on the numerical value represented by each of the random numbers; selecting the random numbers in a predetermined order from each of the groups; A wireless communication system that determines the order of multiple selected random numbers based on the numerical value represented by each selected random number, and generates the change pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers.

6. A wireless communication system in which a base wireless device and at least one remote wireless device communicate with each other while changing frequencies, a random number generator that generates a plurality of random numbers using a unique number assigned to the base radio device as a seed; an association unit that associates different random numbers with the frequencies of the respective channels; a pattern generating unit that determines the order of the random numbers based on the numerical value represented by each of the random numbers, and generates a frequency change pattern by arranging the frequencies corresponding to the random numbers in the same order as the random numbers; a base frequency changing unit that changes the frequency of radio waves used in communication from the base radio device to the remote radio device based on the change pattern; a remote frequency change unit that changes the frequency of radio waves used in communication from the remote radio device to the base radio device based on the change pattern; Equipped with The association unit Dividing the plurality of random numbers and the plurality of frequencies into two groups; The pattern generation unit determining an order of the random numbers within the two groups based on the numerical value represented by each of the random numbers; A wireless communication system that generates the change pattern by alternately selecting the random numbers one by one from the two groups in the same order as the random numbers, and arranging the random numbers in the selected order.

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