Wireless communication system, wireless communication method, relay device, and wireless communication program

Abstract

The present disclosure relates to a wireless communication system, a wireless communication method, a relay device, and a wireless communication program. This wireless communication system is provided with: a plurality of wireless devices; a relay device that has the plurality of wireless devices subordinate thereto; and a control device that controls the plurality of wireless devices via the relay device. The relay device executes: a process for transmitting, to the control device, an inquiry that includes a desired frequency and that is received from a target wireless device which is one of the plurality of wireless devices subordinate to the relay device; a process for receiving a response that is received from the control device and that includes usable frequency, usable power, and an allowable time limit of a wireless resource, with respect to the target wireless device; a restriction process for restricting a response to the target wireless device by shortening the allowable time limit of the wireless resource on the basis of another response which is a response targeting another wireless device; and a transfer process for transferring a corrected response based on the restriction to the target wireless device. The target wireless device is configured to carry out a process for performing wireless communication on the basis of the corrected response received from the relay device.

Description

Wireless communication system, wireless communication method, relay device, and wireless communication program

[0001] The present disclosure relates to a wireless communication system, a wireless communication method, a relay device, and a wireless communication program.

[0002] A method for controlling the total amount of interference to an interfered system is known as AFC (Automated Frequency Coordination) for wireless LANs. In AFC, each wireless device transmits an inquiry message about the wireless resources it uses to a control device. The control device responds with the range of wireless resources that each wireless device can use, taking into account the conditions of the interfered device.

[0003] In a wireless communication system using AFC, a relay device may be installed between the control device and the wireless device. The relay device can relay messages between the wireless devices and the control device under its control. The relay device can also concatenate and store the messages it relays, or modify and transmit them as response messages.

[0004] Wi-Fi Alliance, "Wi-Fi Alliance furthers Automated Frequency Coordination specification and compliance development to accelerate Wi-Fi 6E", June 30, 2021, <URL: https: / / www.wi-fi.org / news-events / newsroom / wi-fi-alliance-furthers-automated-frequency-coordination-specification-and>Wi-Fi Alliance, "DRAFT AFC System to AFC Device Interface Specification", v0.1.17, P9

[0005] However, systems such as AFC do not adjust frequency allocations between wireless devices individually because they respond to inquiries from each wireless device individually, which means that there is no adjustment to prevent interference between wireless devices, which can lead to mutual interference that reduces the throughput of wireless communications.

[0006] In order to solve the above-mentioned problems, a first object of the present disclosure is to provide a wireless communication system that can reduce the amount of interference to an interfered device and simultaneously avoid mutual interference between wireless devices.

[0007] A second object of the present disclosure is to provide a wireless communication method that can reduce the amount of interference to an interfered device and simultaneously avoid mutual interference between wireless devices.

[0008] A third object of the present disclosure is to provide a relay device that can reduce the amount of interference to an interfered device and simultaneously avoid mutual interference between wireless devices.

[0009] A fourth object of the present disclosure is to provide a wireless communication program that can reduce the amount of interference to an interfered device and simultaneously avoid mutual interference between wireless devices.

[0010] A first aspect of the present disclosure is a wireless communication system including a plurality of wireless devices, a relay device having the plurality of wireless devices under its control, and a control device that controls the plurality of wireless devices via the relay device, wherein the relay device is configured to perform the following processes: a process of transmitting to the control device a query including a desired frequency received from each of the plurality of wireless devices under its control, the query including a desired frequency; a process of receiving from the control device a response including an available frequency, available power, and an allowable period of wireless resources for the target wireless device; a restriction process of restricting the response to the target wireless device by shortening the allowable period of wireless resources based on an other response that is a response intended for another wireless device; and a forwarding process of forwarding a modified response based on the restriction to the target wireless device; and the target wireless device is preferably configured to perform a process of performing wireless communication based on the modified response received from the relay device.

[0011] A second aspect of the present disclosure is a wireless communication method including a plurality of wireless devices, a relay device having the plurality of wireless devices under its control, and a control device that controls the plurality of wireless devices via the relay device, wherein the relay device transmits to the control device a query including a desired frequency received from each of the plurality of wireless devices under its control, the query including a desired frequency, the query including a desired frequency, the available power, and an allowable period of wireless resources for the target wireless device, received from the control device; based on the other response that is a response intended for another wireless device, restricting the response to the target wireless device by shortening the allowable period of wireless resources; and forwarding a modified response based on the restriction to the target wireless device, and the target wireless device preferably performs wireless communication based on the modified response received from the relay device.

[0012] A third aspect of the present disclosure is preferably a relay device that has a plurality of wireless devices under its control and is mediated by a control device that controls the plurality of wireless devices, and is configured to perform the following processes: transmitting an inquiry including a desired frequency received from a target wireless device, which is one of the plurality of wireless devices under its control, to the control device; receiving a response received from the control device, which includes an available frequency, available power, and an allowable period for wireless resources for the target wireless device; restricting the response to the target wireless device by shortening the allowable period for wireless resources based on an other response that is a response intended for another wireless device; and forwarding a modified response based on the restriction to the target wireless device.

[0013] A fourth aspect of the present disclosure is preferably a wireless communication program to be executed by a relay device via a control device that has multiple wireless devices under its control and controls the multiple wireless devices, and includes a program for causing a computer to execute the following processes: a process of transmitting an inquiry including a desired frequency received from a target wireless device that is one of the multiple wireless devices under its control to the control device; a process of receiving a response including an available frequency, available power, and an allowable period for wireless resources for the target wireless device received from the control device; a process of restricting the response to the target wireless device by shortening the allowable period for wireless resources based on an other response that is a response intended for another wireless device; and a process of transferring a modified response based on the restriction to the target wireless device.

[0014] According to the first to fourth aspects of the present disclosure, it is possible to reduce the amount of interference to an interfered device and simultaneously avoid mutual interference between wireless devices.

[0015] FIG. 1 is a diagram illustrating an AFC system of a comparative example. FIG. 2 is a diagram illustrating an AFC system according to a first embodiment of the present disclosure. FIG. 3 is a diagram illustrating an inquiry and a response performed by the AFC system according to the first embodiment of the present disclosure. FIG. 4 is a diagram illustrating a period of wireless resources restricted by a relay device according to the first embodiment of the present disclosure. FIG. 5 is a diagram illustrating a hardware configuration of a relay device according to the first embodiment of the present disclosure. FIG. 6 is a flowchart illustrating processing by a relay device according to the first embodiment of the present disclosure. FIG. 7 is a diagram illustrating an inquiry and a response performed by an AFC system according to a second embodiment of the present disclosure. FIG. 8 is a diagram illustrating a period of wireless resources restricted by a relay device according to the second embodiment of the present disclosure. FIG. 9 is a diagram illustrating an inquiry and a response performed by an AFC system according to a third embodiment of the present disclosure. FIG. 10 is a diagram illustrating a period of wireless resources restricted by a relay device according to the third embodiment of the present disclosure.

[0016] First Embodiment [AFC System of Comparative Example] Prior to describing the first embodiment, an AFC system of a comparative example will be described. Fig. 1 is a diagram showing the AFC system of the comparative example. The AFC system 500 includes a control device 2. The control device 2 controls wireless devices 4a to 4e.

[0017] The AFC system 500 also includes a relay device 6. The relay device 6 relays and connects messages between the control device 2 and the wireless devices 4a to 4e.

[0018] The AFC system 500 also includes an interfered device 8. This disclosure deals with a situation in which the interfered device 8 and wireless devices 4a to 4e share the same frequency band. That is, there is a risk of interference 10a to 10e occurring between the wireless devices 4a to 4e and the interfered device 8. The AFC system 500 is a system that reduces this risk.

[0019] The following describes a method for controlling the amount of interference with an interfered system, which is implemented by the AFC system 500. First, the control device 2 receives in advance information related to wireless communication with the interfered device 8. Examples of the information received here include the location information, operating frequency, and allowable amount of interference of the interfered device 8.

[0020] Next, the wireless devices 4a to 4e issue an inquiry 12 to the control device 2. Examples of information included in the inquiry 12 include the location of the wireless device, the desired frequency, and the transmission power of each frequency. If the wireless devices are fixed, their location information may be registered in the control device in advance. In the AFC system 500, the information from the wireless devices 4a to 4c is relayed by the relay device 6.

[0021] The control device 2 receives the inquiry 12. Then, based on the information regarding the wireless communication of the interfered device 8 and the inquiry 12, the control device 2 derives the frequencies and transmission powers that can be used by each wireless device. The control device 2 then transmits the derived information to the wireless devices 4a to 4e as a response 14. Examples of information contained in the response 14 include whether the frequencies are usable, the usable frequencies, the usable transmission powers, and the time limits for which these can be used.

[0022] The wireless devices 4a to 4e receive the response 14 and perform wireless communication based on the response 14. This limits the frequency and power that each wireless device uses for wireless communication, making it possible to control the amount of interference to the interfered system.

[0023] However, in this method, each wireless device responds to an inquiry individually. Therefore, no adjustment is made to optimize frequency allocation between the wireless devices. Since no adjustment is made to prevent interference between the wireless devices, there is a problem that mutual interference may occur, leading to a decrease in wireless communication throughput. The present disclosure solves this problem.

[0024] 2 is a diagram illustrating an AFC system according to the first embodiment of the present disclosure. The AFC system 100 differs from the AFC system 500 of the comparative example in that the AFC system 100 does not include a wireless device that is not under the control of a relay device.

[0025] The AFC system 100 includes a control device 2. The control device 2 is connected to a relay device 6 via a public network 15. The relay device 6 is connected to wireless devices 4a to 4n. The AFC system 100 also includes interfered devices 8a and 8b.

[0026] In this embodiment, the relay device 6 limits the content of responses from the control device 2 to the wireless devices 4a to 4n. In this case, the limit is imposed by shortening the allowable period of wireless resources, thereby reducing interference between the wireless devices. In other words, it is possible to reduce the amount of interference to the interfered device and avoid mutual interference between the wireless devices at the same time.

[0027] 3 is a diagram showing inquiries and responses performed by the AFC system according to the first embodiment of the present disclosure, with time indicated on the vertical axis progressing downward.

[0028] First, processing is performed for wireless device 4a. At time T0, wireless device 4a transmits a query 12a addressed to the control device 2 to the relay device 6. Examples of information included in the query 12a include desired frequencies and transmission power for each frequency. In this example, f1, f2, and f3 are requested as desired frequencies. The relay device 6 relays the query 12a and transmits a query 12b with the same content to the control device 2.

[0029] The control device 2 receives the inquiry 12b. Then, based on the inquiry 12b, the control device 2 derives the frequencies and periods that the wireless device 4a can use. Then, the control device 2 transmits the derived information to the relay device 6 as a response 14. Examples of information included in the response 14 include the usable frequencies and powers as well as the allowable time limit for the wireless resources. In this example, the usable frequencies and powers are power 1 for frequency f1 and power 2 for frequency f2. Furthermore, the allowable time limit for the wireless resources is T2.

[0030] When the relay device 6 receives the response 14, it restricts its content. At this time, it estimates the wireless resources required by wireless devices other than the wireless device 4a based on past responses to those devices. Then, to avoid mutual interference with the estimated wireless resources, it restricts the allowable period of the wireless resources in the response 16. Here, the allowable period of the wireless resources is shortened by changing the wireless resource allowable time limit from time T2 to time T1. Then, it transmits the restricted response 16 to the wireless device 4a. The wireless device 4a performs wireless communication based on the response 16.

[0031] Next, processing is performed for wireless devices other than wireless device 4a. Here, processing for wireless device 4b will be described as an example. Wireless device 4b transmits a query 18a addressed to the control device 2 to the relay device 6 at time T1. Examples of information contained in the query 18a include the location information of the wireless device, desired frequencies, and transmission power for each frequency. In this example, f1, f2, and f3 are being queried as desired frequencies. The relay device 6 relays the query 18a and transmits a query 18b with the same content to the control device 2.

[0032] The control device 2 receives the inquiry 18b. Then, based on the inquiry 18b, the control device 2 derives the frequencies and periods that the wireless device 4b can use. Then, the control device 2 transmits the derived information to the relay device 6 as a response 20. Examples of information included in the response 20 include the usable frequencies and powers, as well as the allowable time limit for the wireless resources. In this example, the usable frequencies and powers are power 1 for frequency f1 and power 2 for frequency f2. Furthermore, the allowable time limit for the wireless resources is T3.

[0033] When the relay device 6 receives the response 20, it restricts its content. As described above, the response 16 for the wireless device 4a shortens the allowable period of wireless resources. As a result, even if the wireless device 4b performs wireless communication with the same content as the response 20, mutual interference between the wireless devices 4a and 4b does not occur. Therefore, the relay device 6 transmits a response 22 with the same content as the response 20 to the wireless device 4b. The wireless device 4b performs wireless communication based on the response 22.

[0034] 4 is a diagram illustrating a period of time for which a relay device according to the first embodiment of the present disclosure limits radio resources, with the time indicated on the horizontal axis progressing to the right.

[0035] A range 114 indicated by a dotted line, and ranges 116 and 122 indicated by solid lines indicate the ranges of wireless resources permitted in responses 14, 16, and 22, respectively. In response 14 from the control device 2, wireless device 4a is permitted wireless resources for the period from time T0 to time T2. Here, it is assumed that the relay device 6 estimates, based on past responses to other wireless devices, that wireless devices other than wireless device 4a will require wireless resources from time T1 onwards.

[0036] Therefore, in response 16, relay device 6 limits the allowable time limit for the wireless resources to be from time T0 to time T1. That is, the allowable range of wireless resources is limited to the range 114 to the range 116.

[0037] This makes it possible to prevent overlap between the range 116 and the range 122. That is, even if a wireless device other than the wireless device 4a actually requires wireless resources after time T1, it is possible to avoid mutual interference with the wireless device 4a.

[0038] [Hardware Configuration of Relay Device According to First Embodiment] Fig. 5 is a diagram showing the hardware configuration of a relay device according to the first embodiment of the present disclosure. The relay device 6 includes a CPU 118. The CPU 118 is connected to a bus line 121. Memory devices such as a ROM 122, a RAM 124, and a storage 126 are connected to the bus line 121. A communication program executed by the CPU 118 is stored in the memory device. The relay device 6 can realize functions specific to this embodiment by the CPU 118 executing the communication program.

[0039] A communication interface 128 is also connected to the bus line 121. The relay device 6 communicates with the network via the communication interface 128. An operation unit 130 and a display unit 132 are also connected to the bus line 121. The operation unit 130 and the display unit 132 function as a user interface for operating the relay device 6.

[0040] As described above, the relay device 6 can realize the functions specific to this embodiment by the CPU 118 executing the communication program. That is, the relay device 6 can also be realized by a computer and the program. The program can also be recorded on a recording medium or provided over a network.

[0041] 6 is a flowchart showing the process of the relay device according to the first embodiment of the present disclosure. First, in step 100, the initial state is set to a steady state.

[0042] Next, in step 102, it is confirmed whether there is a response from the control device 2. For example, it is confirmed whether the relay device 6 has received a response 14. If there is a response, the process proceeds to step 104. If there is no response, the process returns to step 100, and the current state is set as a new steady state.

[0043] Next, in step 104, it is confirmed whether the allowable period of the wireless resource included in the response is equal to or greater than a threshold. That is, it is confirmed whether the wireless resource included in the response will cause mutual interference with the estimated wireless resource of the other wireless device. If mutual interference occurs, the process proceeds to step 106. If mutual interference does not occur, the process returns to step 100, and the current state is set as a new steady state.

[0044] For example, if the allowable period of the wireless resources included in response 14 is from time T0 to time T2, and the allowable period of the wireless resources estimated to be required by another wireless device is from time T1 to time T3, mutual interference will occur during the period from time T1 to time T2.

[0045] Next, the allowed period is shortened in step 106. For example, the relay device 6 shortens the allowed period of the wireless resources by correcting the allowed time limit of the wireless resources included in the response 16 from time T2 to time T1.

[0046] Next, in step 108, a response including the shortened allowable period is transferred to the corresponding wireless device. For example, relay device 6 transfers response 16 including the content that the allowable period of the wireless resource has been revised to time T2 to wireless device 4a. Then, the process returns to step 100, and the current state is set as the new steady state.

[0047] As described above, in this embodiment, the content of a response from a control device to a wireless device is limited in a manner that avoids mutual interference with estimated wireless resources for wireless devices other than the wireless device in question. In particular, in this embodiment, the allowable period of wireless resources is limited. By performing such processing in an AFC system, it is possible to reduce the amount of interference with an interfered device and simultaneously avoid mutual interference between wireless devices.

[0048] 7 is a diagram showing inquiries and responses performed by an AFC system according to a second embodiment of the present disclosure. The time indicated on the vertical axis progresses downward. The configuration of the AFC system according to the second embodiment is the same as that of the first embodiment. However, the second embodiment differs from the first embodiment in that when a relay device 6 restricts the content of a response to a wireless device under its control, it not only shortens the allowable period of wireless resources but also imposes restrictions on frequency and power.

[0049] First, the process is carried out for the wireless device 4a. The inquiry 12a, inquiry 12b and response 14 are the same as those in the first embodiment, and therefore the description thereof will be omitted.

[0050] When the relay device 6 receives the response 14, it restricts its content. At this time, it estimates the wireless resources required by wireless devices other than the wireless device 4a based on past responses to those devices. Then, to avoid mutual interference with the estimated wireless resources, it imposes restrictions on the frequency and power as well as the allowable period of the wireless resources in the response 16. Here, the allowable period of the wireless resources is shortened by restricting the allowable period of the wireless resources from time T2 to time T1. Furthermore, it imposes a restriction on the frequency by deleting f2 from the allowable frequencies. Then, it transmits a response 16a with restricted content to the wireless device 4a. The wireless device 4a performs wireless communication based on the response 16a.

[0051] Next, processing is performed for wireless devices other than wireless device 4a. Here, processing for wireless device 4b will be described as an example. Since query 18a, query 18b, response 20, and response 22 are the same as those in the first embodiment, their explanations will be omitted.

[0052] As described above, in this embodiment, the content of a response from a control device to a wireless device is limited in a manner that avoids mutual interference with estimated wireless resources of wireless devices other than the wireless device in question. In particular, in this embodiment, the allowable period, frequency, and power of the wireless resources are limited. By performing such processing in an AFC system, it is possible to reduce the amount of interference with an interfered device and avoid mutual interference between wireless devices.

[0053] 8 is a diagram illustrating a period of time for which a relay device according to a second embodiment of the present disclosure restricts radio resources. The horizontal axis indicates time progressing to the right, and the vertical axis indicates frequency.

[0054] The range 114 indicated by the dotted line, and the ranges 116a and 122 indicated by the solid lines indicate the ranges of radio resources permitted in the responses 14, 16a, and 22, respectively. In the response 14 from the control device 2, the radio device 4a is permitted radio resources at frequencies f1 and f2 for the period from time T0 to time T2. Here, it is assumed that the relay device 6 estimates the radio resources required by radio devices other than the radio device 4a based on past responses to other radio devices. The estimated radio resources are, for example, the use of frequency f1 from time T1 onwards, or the use of frequency f2 from time T0 onwards.

[0055] Therefore, in response 16a, relay device 6 limits the allowable time limit for wireless resources at frequency f1 to time T0 to time T1. Furthermore, in response 16a, relay device 6 deletes frequency f2 from the allowable frequency range, i.e., limits the allowable wireless resource range from range 114 to range 116a.

[0056] This makes it possible to prevent overlap between range 116 and range 122. In other words, even if a wireless device other than wireless device 4a actually requires wireless resources of frequency f1 after time T1 or frequency f2 after time T0, it is possible to avoid mutual interference with wireless device 4a.

[0057] 9 is a diagram showing an inquiry and a response performed by an AFC system according to a third embodiment of the present disclosure. The time indicated on the vertical axis progresses downward. The configuration of the AFC system according to the third embodiment is the same as that of the first and second embodiments. However, the third embodiment differs from the first embodiment in that the relay device 6 transfers a response to a subordinate wireless device after the allowable time limit for a response previously received from another wireless device.

[0058] First, the process is carried out for the wireless device 4a. The inquiry 12a, inquiry 12b and response 14 are the same as those in the first embodiment, and therefore the description thereof will be omitted.

[0059] Upon receiving the response 14, the relay device 6 transmits a response 16 having the same content to the wireless device 4a. The wireless device 4a then performs wireless communication based on the response 16.

[0060] Next, processing is performed for wireless devices other than the wireless device 4a. Here, processing for the wireless device 4b will be described as an example. The inquiry 18a, inquiry 18b, and response 20 are the same as those in the first embodiment, so their explanation will be omitted.

[0061] The relay device 6 receives the response 20. As described above, the response 16 for the wireless device 4a does not shorten the allowable period of wireless resources. As a result, if the wireless device 4b performs wireless communication with the same content as the response 20, mutual interference between the wireless devices 4a and 4b may occur from time T1 to time T2. Therefore, the relay device 6 delays the transfer of the response 22a, which has the same content as the response 20, until after time T2. The wireless device 4b performs wireless communication based on the response 22a.

[0062] 10 is a diagram illustrating a period of time for which a relay device according to a third embodiment of the present disclosure limits radio resources, with the horizontal axis indicating time progressing to the right.

[0063] The range 120 indicated by the dotted line, and the range 114 and range 122a indicated by the solid line indicate the ranges of radio resources permitted in the responses 20, 14, and 22a, respectively. In the response 14 from the control device 2, the radio device 4a is permitted radio resources for the period from time T0 to time T2. In the third embodiment, since the query 18a is transmitted at time T2, the response 20 can be permitted radio resources for the period from time T1 to time T2. As a result, the range 114 and the range 120 may overlap. In other words, mutual interference between the radio devices 4a and 4b may occur in the period from time T1 to time T2.

[0064] Therefore, the relay device 6 transfers the response 22 after the time T2, which is the allowable time limit included in the response 16. That is, the allowable range of wireless resources is limited from the range 120 to the range 122a.

[0065] This makes it possible to prevent overlap between the range 114 and the range 120. In other words, when a wireless device other than the wireless device 4a uses the wireless resources, the wireless device 4a has already completed using the wireless resources. In other words, it is possible to prevent mutual interference between the wireless device 4a and the wireless devices other than the wireless device 4a.

[0066] As described above, in this embodiment, the relay device transfers a response to a wireless device after the allowable time limit for a response that was previously received from another wireless device has expired. By performing such processing in the AFC system, it is possible to reduce the amount of interference with the interfered device and avoid mutual interference between wireless devices.

[0067] 2 Control device 4a, 4b, 4n Wireless device 6 Relay device 10a, 10b, 10c, 10d, 10e Interference 12, 12a, 12b Inquiry 14 Response 16, 16a Response 18a, 18b Inquiry 20 Response 22, 22a Response

Claims

1. A wireless communication system comprising a plurality of wireless devices, a relay device having the plurality of wireless devices under its control, and a control device that controls the plurality of wireless devices via the relay device, wherein the relay device is configured to perform the following processes: a process of transmitting to the control device a query including a desired frequency received from a target wireless device which is one of the plurality of wireless devices under its control; a process of receiving from the control device a response including an available frequency, available power, and an allowable period of wireless resources for the target wireless device; a restriction process of restricting the response to the target wireless device by shortening the allowable period of wireless resources based on an other response which is a response intended for another wireless device; and a transfer process of transferring a modified response based on the restriction to the target wireless device, and the target wireless device is configured to perform a process of performing wireless communication based on the modified response received from the relay device.

2. The wireless communication system according to claim 1, wherein the relay device is further configured to perform a process of estimating wireless resources required by wireless devices other than the target wireless device based on the past other responses, and the restriction process is performed so as to avoid mutual interference with the estimated wireless resources.

3. The wireless communication system according to claim 2, wherein the restriction process is performed by restricting the available frequencies.

4. The wireless communication system according to claim 2, wherein the restriction process is performed by restricting the available power.

5. The wireless communication system according to claim 1, wherein the forwarding process is performed after the permissible time limit included in the previously received other response.

6. A wireless communication method comprising a plurality of wireless devices, a relay device having the plurality of wireless devices under its control, and a control device that controls the plurality of wireless devices via the relay device, wherein the relay device: transmits to the control device a query including a desired frequency received from a target wireless device which is one of the plurality of wireless devices under its control; receives from the control device a response including an available frequency, available power, and an allowable period of wireless resources for the target wireless device; restricts the response to the target wireless device by shortening the allowable period of wireless resources based on an other response which is a response intended for another wireless device; and transfers a modified response based on the restriction to the target wireless device; and the target wireless device performs wireless communication based on the modified response received from the relay device.

7. A relay device having a plurality of wireless devices under its control and connected via a control device that controls the plurality of wireless devices, the relay device being configured to perform the following processes: a process of transmitting an inquiry including a desired frequency received from a target wireless device, which is one of the plurality of wireless devices under its control, to the control device; a process of receiving a response including an available frequency, available power, and an allowable period of wireless resources for the target wireless device received from the control device; a process of restricting the response to the target wireless device by shortening the allowable period of wireless resources based on an other response that is a response intended for another wireless device; and a process of transferring a modified response based on the restriction to the target wireless device.

8. A wireless communication program to be executed by a relay device via a control device that has multiple wireless devices under its control and controls the multiple wireless devices, the wireless communication program including a program for causing a computer to execute the following processes: a process of transmitting an inquiry including a desired frequency received from a target wireless device that is one of the multiple wireless devices under its control to the control device; a process of receiving a response including an available frequency, available power, and an allowable period of wireless resources for the target wireless device received from the control device; a process of restricting the response to the target wireless device by shortening the allowable period of wireless resources based on an other response that is a response intended for another wireless device; and a process of transferring a modified response based on the restriction to the target wireless device.