JP7614812B2 - Channel determination device, channel determination system, channel determination method and program - Google Patents

Description

This disclosure relates to a channel determination device, a channel determination system, a channel determination method, and a program.

An access point has been proposed that communicates with a wireless terminal by selecting a communication channel different from the communication channel used by other access points in the wireless communication area of the access point itself, based on the communication channel and pseudo radio wave density used by other access points within the wireless communication area of the access point itself (see, for example, Patent Document 1). Here, the access point receives a beacon transmitted from another access point, and, based on information contained in the received beacon, identifies the number of access points that use the same communication channel as the access point itself among those that have wireless communication areas that overlap with the wireless communication area of the access point itself. The access point then calculates the pseudo radio wave density for each of a number of communication channels that have been set in advance, from the number of access points identified.

JP 2006-005603 A

However, in the case of the access point described in Patent Document 1, when it is used together with multiple other access points that overlap with the wireless communication area of the own device, it may not be possible to sufficiently equalize the usage rate of each of the multiple communication channels. In this case, there is a risk that a communication channel with an extremely high usage rate will be generated, causing a significant decrease in the communication speed between the access point and the wireless terminal using that communication channel.

The present disclosure has been made in consideration of the above-mentioned reasons, and aims to provide a channel determination device, a channel determination system, a channel determination method, and a program that can suppress a decrease in communication speed caused by an imbalance in the channels used.

In order to achieve the above object, a channel determination device according to the present disclosure comprises:
A channel determination device that determines a channel to be used by each of a plurality of access points from a plurality of preset channels,
an influence coefficient calculation unit that calculates, for each of the plurality of access points, an influence coefficient indicating a degree of influence of a communication state of each of the plurality of access points on a communication state of the other access points;
a channel usage rate calculation unit that calculates a channel usage rate of each of the plurality of channels for each combination of a plurality of types of channels that can be used by each of the plurality of access points, based on a self usage rate indicating a usage rate of each of the plurality of channels for each of the plurality of access points, a surrounding congestion degree that reflects a usage state of each of the plurality of channels by other access points at each of the plurality of access points, and the influence coefficient;
a maximum value calculation unit that calculates a maximum value of the channel usage rate for each combination of the plurality of types of channels;
and a selection unit that selects, from among the plurality of types of channel combinations, the channel combination that minimizes the maximum value.

According to the present disclosure, a channel usage rate calculation unit calculates the channel usage rate of each of multiple channels for each combination of multiple types of channels that can be used by each of multiple access points based on the self usage rate, surrounding congestion level, and influence coefficient of each of the multiple access points. Then, a maximum value calculation unit calculates the maximum value of the channel usage rate for each combination of multiple types of channels, and a selection unit selects, from the combinations of multiple types of channels, a channel combination that has the smallest maximum channel usage rate. This makes it possible to set the channel combinations used by each of the multiple access points so that the usage rate of each channel is uniform and low, thereby suppressing a decrease in communication speed caused by an imbalance in the channels used.

FIG. 1 is a diagram showing a state in which a channel determination system according to an embodiment of the present disclosure is used; FIG. 1 is a block diagram showing a hardware configuration of a channel determination system according to an embodiment. FIG. 2 is a block diagram showing a functional configuration of a control device according to an embodiment. FIG. 1 is a block diagram showing a functional configuration of a cloud server according to an embodiment. FIG. 1A is a diagram showing an example of information stored in an influence coefficient storage unit according to an embodiment; FIG. 1B is a diagram showing an example of information stored in a surrounding congestion degree storage unit according to an embodiment; FIG. 13 is a diagram showing an example of information stored in a self-utilization rate storage unit according to an embodiment; FIG. 1 is a diagram showing an example of information stored in a channel combination storage unit according to an embodiment; A sequence diagram showing the operation of the channel determination system according to the embodiment. A sequence diagram showing the operation of the channel determination system according to the embodiment. A flowchart showing an example of the flow of a channel determination process executed by a cloud server according to an embodiment. FIG. 1A is a diagram showing an example of an area in which a control device is installed, and FIG. 1B is a diagram illustrating the operation of a cloud server according to an embodiment. A flowchart showing an example of the flow of a channel determination process executed by a cloud server according to an embodiment. FIG. 1 is a diagram showing an example of information stored in a channel combination storage unit according to an embodiment; A flowchart showing an example of the flow of a channel selection process executed by a cloud server according to an embodiment. FIG. 13 is a block diagram showing a functional configuration of a cloud server according to a modified example.

The channel determination device and the channel determination system according to the embodiment of the present disclosure will be described below with reference to the attached drawings. The channel determination device according to the embodiment determines a channel to be used by each of a plurality of access points from among a plurality of channels set in advance. The channel determination device includes an influence coefficient calculation unit that calculates an influence coefficient indicating the degree of influence of the communication state of each of the plurality of access points on the communication state of each of the plurality of access points for each of the plurality of access points, a channel usage rate calculation unit that calculates the channel usage rate of each of the plurality of channels for each combination of a plurality of types of channels that can be used by each of the plurality of access points based on a self-usage rate indicating the usage rate of each of the plurality of channels for each of the plurality of access points, a surrounding congestion degree reflecting the usage status of each of the plurality of channels by other access points at each of the plurality of access points, and the influence coefficient, a maximum value calculation unit that calculates the maximum value of the channel usage rate for each combination of a plurality of types of channels, and a selection unit that selects a channel combination with the minimum maximum value from among the combinations of a plurality of types of channels.

As shown in FIG. 1, the channel determination system according to the present embodiment includes a control device 1 installed in each room S11, S12, ..., S33 of an apartment building, and a cloud server 2 capable of communicating with the control device 1 via a local network NW2 and a wide area network NW1. The control device 1 installed in each room S11, S12, ..., S33 can wirelessly communicate with devices 3 having wireless communication functions arranged in each room, and a wireless LAN (Local Area Network) is constructed in each room S11, S12, ..., S33. Here, the control device 1 and devices 3 installed in each room S11, S12, ..., S33 communicate using one channel. Radio waves transmitted from each control device 1 reach rooms other than the room in which it is installed (e.g., room S22) (e.g., rooms S11, S12, S13, S21, S23, S31, S32, S33). That is, the wireless communication area of each control device 1 extends to rooms other than the room in which it is installed. For this reason, for example, when the control devices 1A1, 1A2, 1A3, 1B1, 1B3, 1C1, 1C2, and 1C3 installed in the rooms S11, S12, S13, S21, S23, S31, S32, and S33 communicate with the devices 3 using the same channel as the control device 1B2 installed in the room S22, a busy state may occur and the communication speed may decrease. The local network NW2 is a wired LAN, and is connected to the wide area network NW1 via the router 8 and the line termination device 9. The wide area network NW1 is, for example, the Internet, and is connected to the cloud server 2 and the management server 4 that manages the arrangement of the rooms S11, S12, ..., S33 of the apartment building and the control devices 1. For example, when the management server 4 acquires various information for constructing room map information from a terminal device (not shown) owned by the manager of the apartment complex via the wide area network NW1, it generates room map information showing the layout of each room S11, S12, ..., S33 of the apartment complex based on the acquired information. Then, the management server 4 transmits the generated room map information to the cloud server 2. Also, when the management server 4 acquires SSID information of the control device 1 and room identification information of the room in which the control device 1 is installed via the wide area network NW1 from a terminal device (not shown) owned by a user who has installed the control device 1 in each room S11, S12, ..., S33 of the apartment complex, it generates access point position information (hereinafter referred to as "AP position information") including the SSID information and room identification information. Then, the management server 4 transmits the generated AP position information to the cloud server 2.

The devices 3 are personal computers, electrical devices that have the ability to communicate using a communication protocol that complies with the EchonetLite standard, etc., and each device is equipped with a wireless module (not shown) for wireless communication with the control device 1.

The control device 1 controls the devices 3 arranged in, for example, each of the rooms S11, S12, ..., S33, and functions as an access point that performs wireless communication with the devices 3. As shown in FIG. 2, the control device 1 includes a CPU (Central Processing Unit) 101, a main memory unit 102, an auxiliary memory unit 103, a wireless module 106, and a wired communication interface (hereinafter referred to as "wired communication I/F") 107. The main memory unit 102 is composed of a volatile memory and is used as a working area for the CPU 101. The auxiliary memory unit 103 has a non-volatile memory such as a ROM (Read Only Memory) and storage, and stores a control program for controlling the operation of the control device 1, content information, etc. The wireless module 106 establishes a communication link with the device 3 to perform wireless communication. The wireless module 106 has a signal generation circuit that generates a wireless signal, an antenna, and a demodulation circuit that demodulates the wireless signal received by the antenna, and communicates using a communication protocol such as IEEE802.11a, b, g, n, etc. The wired communication I/F 107 is connected to the local network NW2 and communicates using a communication protocol that conforms to the Ethernet (registered trademark) standard, for example.

In the control device 1, the CPU 101 loads the control program stored in the auxiliary memory unit 103 into the main memory unit 102 and executes it, so that, as shown in FIG. 3, it functions as a beacon information acquisition unit 111, an access point identification information extraction unit (hereinafter referred to as the "AP identification information extraction unit") 112, a radio wave intensity acquisition unit 113, a busy state detection unit 114, an occurrence rate calculation unit 115, a communication control unit 116, a utilization rate calculation unit 117, an access point information generation unit (hereinafter referred to as the "AP information generation unit") 118, an access point information transmission unit (hereinafter referred to as the "AP information transmission unit") 119, a channel information acquisition unit 120, a determination unit 121 and a channel update request unit 122. In addition, the auxiliary storage unit 103 shown in FIG. 2 includes a surrounding access point information storage unit (hereinafter referred to as the "surrounding AP information storage unit") 131 that stores information about the control devices 1 arranged around the device itself, an occurrence ratio storage unit 132, a usage rate storage unit 133, and a channel storage unit 134, as shown in FIG. 3.

The occurrence rate memory unit 132 stores busy occurrence rate information indicating the rate at which a busy state occurs within a preset reference time. The usage rate memory unit 133 stores self-usage rate information indicating the usage rate of the device itself for each of multiple channels. The channel memory unit 134 stores channel information indicating the channels assigned to the device itself.

When the wireless module 106 receives a beacon transmitted from another surrounding control device 1, the beacon information acquisition unit 111 acquires beacon information obtained by demodulating the received beacon from the wireless module 105. The AP identification information acquisition unit 112 extracts access point identification information (hereinafter referred to as "AP identification information") that identifies the control device 1 that transmitted the beacon, which is included in the beacon information. The AP identification information acquisition unit 112 then stores the extracted AP identification information in the surrounding AP information storage unit 131. The radio wave strength acquisition unit 113 acquires radio wave strength information indicating the radio wave strength in the own device of the radio wave transmitted from the control device 1 that transmitted the beacon, which is calculated based on the reception strength when the wireless module 105 receives the beacon. The radio wave strength acquisition unit 113 then stores the acquired radio wave strength information in the surrounding AP information storage unit 131.

The communication control unit 116 controls communication with the device 3 via the wireless module 106 using the CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) communication protocol. The communication control unit 116 controls the control device 1 to communicate with the device 3 using the channel stored in the channel storage unit 134. The communication control unit 116 also detects the length of the self-use period during which the device uses the channel stored in the channel storage unit 134 at every preset reference time, and notifies the usage rate calculation unit 117 of information indicating the length of the detected self-use period.

The busy state detection unit 114 detects the length of a busy state period during which another control device 1 uses the same channel as the own device for each reference time by performing carrier sense, and detects the SSID of the other control device 1 using the same channel as the own device. The busy state detection unit 114 then notifies the occurrence rate calculation unit 115 of information indicating the length of the detected busy state period. When a preset busy occurrence rate determination time arrives, the occurrence rate calculation unit 115 calculates the busy occurrence rate per the reference time based on the information indicating the length of the busy state period notified by the busy state detection unit 114. This busy occurrence rate determination time arrives at each reference time, and is a time to determine whether or not to request a channel update from the cloud server 2 based on the busy occurrence rate per the reference time. The occurrence rate calculation unit 115 then stores busy occurrence rate information indicating the calculated busy occurrence rate in the occurrence rate storage unit 132.

The usage rate calculation unit 117 calculates the usage rate of the channels stored in the channel storage unit 134 by the device itself per the aforementioned reference time based on information indicating the length of the self-use period notified from the communication control unit 116. Then, the usage rate calculation unit 117 stores the self-use rate information indicating the calculated usage rate in the usage rate storage unit 133. The AP information generation unit 118 acquires the SSID information and radio wave strength information of the other control devices 1 stored in the surrounding AP information storage unit 131 and the usage rate information stored in the usage rate storage unit 133, and generates AP information including the acquired SSID information, radio wave strength information, and usage rate information of the other control devices 1. Then, the AP information transmission unit 119 transmits the AP information generated by the AP information generation unit 118 to the cloud server 2. The channel information acquisition unit 120 acquires channel information indicating a combination of channels used by each of the multiple control devices 1 transmitted from the cloud server 2, identifies the channels used by the device itself based on the acquired channel information, and stores information indicating the identified channels in the channel storage unit 134.

The determination unit 121 determines whether the busy occurrence rate indicated by the busy occurrence rate information stored in the occurrence rate storage unit 132 is equal to or greater than a preset reference busy occurrence rate. When the determination unit 121 determines that the busy occurrence rate is equal to or greater than the reference busy occurrence rate, the channel update request unit 122 transmits channel update request information to the cloud server 2 requesting the cloud server 2 to update the channel used by the control device 1.

Returning to FIG. 2, the cloud server 2 functions as a channel determination device that determines which of a plurality of pre-set channels each of the plurality of control devices 1 will use, and includes a CPU 201, a main memory unit 202, an auxiliary memory unit 203, a clock unit 207, a wide area communication unit 208, and a bus 209 that connects the various units. The main memory unit 202 is a volatile memory that is used as a working area for the CPU 201. The auxiliary memory unit 203 has a non-volatile memory such as a magnetic disk or semiconductor memory, and stores programs for implementing various functions of the cloud server 2. The clock unit 207 is, for example, an RTC (Real Time Clock). The wide area communication unit 208 has a modem, a gateway, etc., and is connected to the wide area network NW1.

In the cloud server 2, the CPU 201 loads the program stored in the auxiliary memory unit 203 into the main memory unit 202 and executes it, thereby functioning as a room map acquisition unit 211, an access point position information acquisition unit (hereinafter referred to as the "AP position information acquisition unit") 212, an access point information acquisition unit (hereinafter referred to as the "AP information acquisition unit") 213, an AP identification information extraction unit 214, a radio wave intensity extraction unit 215, an influence coefficient calculation unit 216, an ambient congestion calculation unit 217, a self-utilization rate extraction unit 218, a channel utilization rate calculation unit 219, a maximum value calculation unit 220, an average value calculation unit 221, a standard deviation calculation unit 222, a selection unit 223, a channel information transmission unit 224 and a channel update request acquisition unit 225, as shown in FIG. 4. 2 includes an access point position information storage unit (hereinafter referred to as "AP position information storage unit") 231, an influence coefficient storage unit 232, a surrounding congestion level storage unit 233, a self-utilization rate storage unit 234, and a channel information storage unit 235, as shown in FIG. 4. Furthermore, the main storage unit 202 shown in FIG. 2 includes a channel combination storage unit 241, as shown in FIG. 4. The AP position information storage unit 231 stores the position of each room S11, S12, ..., S33 in the apartment building in association with the SSID information of the control device 1 installed in each room S11, S12, ..., S33.

The influence coefficient storage unit 232 stores an influence coefficient indicating the degree of influence of the communication state of the other control device 1 on the communication state of the control device 1 installed in one room, in association with a combination of room identification information identifying the room corresponding to the influence coefficient and room identification information identifying the room in which the other control device 1 is installed, and coefficient identification information identifying the influence coefficient, as shown in FIG. 5(A), for example. The surrounding congestion degree storage unit 233 stores surrounding congestion degree information corresponding to each of the multiple pre-set channels (four channels in FIG. 5(B)) for each of the multiple control devices 1, in association with the AP identification information of the control device 1. The self-utilization rate storage unit 234 stores, as shown in FIG. 6, channel usage information indicating the channels used by each of the multiple control devices 1, and self-utilization rate information indicating the utilization rate of the channels by the multiple control devices 1 themselves, in association with the AP identification information of each of the multiple control devices 1.

The channel combination storage unit 241 temporarily stores information indicating the channel usage rate, average channel usage rate, standard deviation of channel usage rate, and maximum channel usage rate corresponding to each combination of channels used by each of the multiple control devices 1, in association with the channel combination, as shown in FIG. 7, for example. Here, "channel combination" refers to the combination of channels used by the control devices 1 (1A1, 1A2, ..., 1C3) installed in each of the rooms S11, S12, ..., S33. Also, "channel usage rate" refers to the channel usage rate of each channel in the control devices 1 (1A1, 1A2, ..., 1C3) installed in each of the rooms S11, S12, ..., S33.

Returning to FIG. 4, when the room map acquisition unit 211 acquires room map information from the management server 4, it stores the acquired room map information in the AP position information storage unit 231. When the AP position information acquisition unit 212 acquires AP position information including the SSID information of the control device 1 and the room identification information of the rooms S11, S12, ..., S33 in which the control device 1 is installed from the management server 4, it stores the acquired AP position information in the AP position information storage unit 231.

The AP information acquisition unit 213 acquires AP information transmitted from the control device 1, and notifies the acquired AP information to the AP identification information extraction unit 214, the radio wave intensity extraction unit 215, and the self-utilization rate extraction unit 218. Here, when the AP information acquisition unit 213 determines that a preset channel update time has arrived based on the time measured by the clock unit 207, it acquires AP information from the multiple control devices 1 by transmitting AP information request information to the multiple control devices 1, which requests the multiple control devices 1 to transmit AP information. In addition, when the AP information acquisition unit 213 is notified by the channel update request acquisition unit 225 of channel update request information requesting an update of the combination of channels used by the multiple control devices 1, it acquires AP information by transmitting the above-mentioned AP information request information to the multiple control devices 1.

The AP identification information extraction unit 214 extracts the SSID information of the control device 1 included in the AP information and notifies the influence coefficient calculation unit 216 of the extracted SSID information. The radio wave strength extraction unit 215 extracts the radio wave strength information included in the AP information and notifies the influence coefficient calculation unit 216 of the extracted radio wave strength information. The influence coefficient calculation unit 216 calculates an influence coefficient indicating the degree of influence of the communication state of each of the multiple control devices 1 on the communication state of each of the multiple control devices 1 by the communication state of the other control devices 1 for each of the multiple control devices 1. Specifically, the influence coefficient calculation unit 216 calculates an influence coefficient for each of the multiple control devices 1 based on the radio wave strength of the radio waves arriving from each of the other control devices 1 indicated by the radio wave strength information. For example, for each of the multiple control devices 1, if the radio wave strength of the radio waves arriving from the other control devices 1 is equal to or greater than a preset reference radio wave strength, the influence coefficient is set to "1.0", and if it is less than the reference radio wave strength, the influence coefficient is set to "0".

The self-utilization rate extraction unit 218 extracts self-utilization rate information included in the AP information, and stores the extracted self-utilization rate information in the self-utilization rate storage unit 234. The surrounding congestion degree calculation unit 217 calculates a surrounding congestion degree that reflects the usage status of each of a plurality of pre-set channels by the other control devices 1. Specifically, the surrounding congestion degree calculation unit 217 calculates the product of the self-utilization rate of each of a plurality of channels and the influence coefficient for the other control devices 1, and calculates the sum of the calculated products as the surrounding congestion degree. The surrounding congestion degree calculation unit 217 stores surrounding congestion degree information indicating the calculated surrounding congestion degree in the surrounding congestion degree storage unit 233.

The channel usage rate calculation unit 219 calculates the channel usage rate of each of the multiple channels for each combination of multiple types of channels that can be used by each of the multiple access points based on the self usage rate of each of the multiple access points and the surrounding congestion degree at each of the multiple access points. Specifically, the channel usage rate calculation unit 219 refers to the surrounding congestion degree information stored in the surrounding congestion degree storage unit 233 and the self usage rate information stored in the self usage rate storage unit 234, and calculates a value equivalent to the sum of the surrounding congestion degree and the self usage rate as the channel usage rate for each of the multiple control devices 1. Then, the channel usage rate calculation unit 219 stores the channel usage rate information indicating the calculated channel usage rate in the channel combination storage unit 241 in association with the combination of multiple types of channels.

The maximum value calculation unit 220 refers to the channel usage rate information stored in the channel combination storage unit 241 and calculates the maximum value of the channel usage rate for each combination of multiple types of channels. The maximum value calculation unit 220 then stores the maximum value information indicating the calculated maximum value of the channel usage rate in the channel combination storage unit 241 in association with the combination of multiple types of channels. The average value calculation unit 221 refers to the channel usage rate information stored in the channel combination storage unit 241 and calculates the average value of the channel usage rate for each combination of multiple types of channels. The average value calculation unit 221 then stores the average value information indicating the calculated average value in the channel combination storage unit 241 in association with the combination of multiple types of channels. The standard deviation calculation unit 222 refers to the channel usage rate information stored in the channel combination storage unit 241 and calculates the standard deviation of the channel usage rate for each combination of multiple types of channels. The standard deviation calculation unit 222 then stores the standard deviation information indicating the calculated standard deviation in the channel combination storage unit 241 in association with the combination of multiple types of channels.

The selection unit 223 selects a channel combination with the smallest maximum channel usage rate from among the multiple channel combinations. Furthermore, when the selection unit 223 determines that there are multiple channel combinations with the smallest maximum channel usage rate among the multiple channel combinations, the selection unit 223 selects a channel combination with the smallest average channel usage rate from among the multiple channel combinations. Furthermore, when the selection unit 223 determines that there are multiple channel combinations with the smallest maximum channel usage rate and the smallest average channel usage rate among the multiple channel combinations, the selection unit 223 selects at least one channel combination with the smallest standard deviation of channel usage rate from among the multiple channel combinations, and selects one channel combination from the selected channel combinations. Then, the selection unit 223 stores channel information indicating the selected channel combination in the channel information storage unit 235.

The channel information transmission unit 224 transmits channel information indicating the combination of channels used by each of the multiple control devices 1 stored in the channel information storage unit 235 to the multiple control devices 1. When the channel update request acquisition unit 225 acquires the above-mentioned channel update request information from the control device 1, it notifies the AP information acquisition unit 213 of the acquired channel update request information.

Next, the operation of the channel determination system according to the present embodiment will be described with reference to FIG. 8 and FIG. 9. First, as shown in FIG. 8, for example, assume that the manager of an apartment complex performs an operation to register room map information of the apartment complex in the cloud server 2 via a terminal device owned by the manager. In this case, various information for constructing the room map information is transmitted from the terminal device owned by the manager to the management server 4. At this time, the management server 4 generates room map information indicating the arrangement of each room S11, S12, ..., S33 of the apartment complex based on the information acquired from the terminal device of the manager (step S1). Next, the generated room map information is transmitted from the management server 4 to the cloud server 2 (step S2). At this time, the cloud server 2 stores the room map information acquired from the management server 4 in the AP position information storage unit 231. Also, for example, suppose that a user who has installed control devices 1 in rooms S11, S12, ..., S33 performs an operation to register the location of the installed control device 1 via a terminal device owned by the user, that is, an operation to associate the SSID information of the installed control device 1 with the room identification information of the rooms S11, S12, ..., S33 in which the control device 1 is installed. In this case, the SSID information of the control device 1 and the room identification information of the room in which the control device 1 is installed are transmitted from the terminal device owned by the user to the management server 4. At this time, the management server 4 generates AP location information including the SSID information of the control device 1 acquired from the user's terminal device and the room identification information of the room in which the control device 1 is installed (step S3). Next, the generated AP location information is transmitted from the management server 4 to the cloud server 2 (step S4).

After that, when the preset channel update time arrives, the above-mentioned AP information request information is transmitted from the cloud server 2 to the multiple control devices 1 (step S5). On the other hand, when the control device 1 acquires the AP information request information, it acquires beacon information obtained by demodulating the beacons transmitted from the other surrounding control devices 1 (step S6). Next, the control device 1 extracts AP identification information that identifies the control device 1 that transmitted the beacon contained in the beacon information (step S7). Here, the control device 1 stores the extracted AP identification information in the surrounding AP information storage unit 131. Next, the control device 1 acquires radio wave strength information that indicates the radio wave strength in the control device itself of the radio waves transmitted from the control device 1 that transmitted the beacon (step S8). Here, the control device 1 stores the acquired radio wave strength information in the surrounding AP information storage unit 131.

Then, the control device 1 detects the length of the self-use period during which the device itself uses the channel for each of the aforementioned reference times, and calculates the self-use rate of the channel by the device itself per aforementioned reference time based on the detected length of the self-use period (step S9). Here, the control device 1 stores self-use rate information indicating the calculated self-use rate in the usage rate storage unit 133. Next, the control device 1 acquires the SSID information and radio wave strength information of the other control devices 1 stored in the surrounding AP information storage unit 131 and the usage rate information stored in the usage rate storage unit 133, and generates AP information including the acquired SSID information, radio wave strength information, and usage rate information of the other control devices 1 (step S10). Next, the generated AP information is transmitted from the control device 1 to the cloud server 2 (step S11).

Meanwhile, when the cloud server 2 acquires the AP information from the control device 1, it extracts the SSID information of the control device 1 included in the AP information (step S12). After that, the cloud server 2 extracts the radio wave intensity information included in the AP information (step S13). Next, the cloud server 2 extracts the self-utilization rate information included in the AP information (step S14). Here, the cloud server 2 stores the extracted self-utilization rate information in the self-utilization rate storage unit 234.

Next, the cloud server 2 calculates an influence coefficient for each of the multiple control devices 1 based on the radio wave strength of the radio waves arriving from each of the other control devices 1 indicated by the radio wave strength information (step S15). After that, the cloud server 2 calculates the product of the self-usage rate of each of the multiple channels and the influence coefficient for each of the other control devices 1, and calculates the sum of the calculated products as the surrounding congestion degree (step S16). Here, the cloud server 2 stores surrounding congestion degree information indicating the calculated surrounding congestion degree in the surrounding congestion degree storage unit 233. Next, the cloud server 2 calculates the channel usage rate of each of the multiple channels for each combination of multiple types of channels that can be used by each of the multiple access points based on the self-usage rate of each of the multiple access points and the surrounding congestion degree for each of the multiple control devices 1 (step S17).

Then, the cloud server 2 calculates the maximum channel usage rate for each combination of the multiple types of channels (step S18). Next, the cloud server 2 calculates the average channel usage rate for each combination of the multiple types of channels (step S19). Next, the cloud server 2 calculates the standard deviation of the channel usage rate for each combination of the multiple types of channels (step S20). Then, as shown in FIG. 9, the cloud server 2 determines that there are multiple channel combinations in which the maximum channel usage rate is the smallest among the combinations of the multiple types of channels (step S21), and determines that there are multiple channel combinations in which the average channel usage rate is the smallest among the combinations of the multiple channels (step S22). In this case, the cloud server 2 selects at least one channel combination in which the standard deviation of the channel usage rate is the smallest from the combinations of the multiple types of channels in which the maximum channel usage rate is the smallest and the average channel usage rate is the smallest. Then, the cloud server 2 selects one channel combination from the selected channel combinations (step S23). Here, the cloud server 2 stores channel information indicating the selected channel combination in the channel information storage unit 235. Next, the channel information stored in the channel information storage unit 235 is transmitted from the cloud server 2 to the control device 1 (step S24). Meanwhile, when the control device 1 acquires the channel information transmitted from the cloud server 2, it updates the channels used by its own device based on the acquired channel information (step S25).

When the preset busy occurrence rate determination time arrives, the control device 1 calculates the busy occurrence rate per the reference time (step S26). Here, the control device 1 detects the length of the busy state period for each reference time by performing carrier sense. Then, the control device 1 calculates the busy occurrence rate for the other control devices 1 based on the detected length of the busy state period. Here, the control device 1 stores busy occurrence rate information indicating the calculated busy occurrence rate in the occurrence rate storage unit 132. Then, the control device 1 determines that the busy occurrence rate R1 is equal to or greater than the preset reference busy occurrence rate (step S27). In this case, the channel update request information is transmitted from the control device 1 to the cloud server 2 (step S28). On the other hand, when the cloud server 2 acquires the channel update request information transmitted by the control device 1, the cloud server 2 transmits the AP information request information to the multiple control devices 1 (step S5). After that, a series of processes from step S6 onwards are executed.

Next, the channel determination process executed by the cloud server 2 according to the present embodiment will be described with reference to FIG. 10 to FIG. 13. This channel determination process is started, for example, when the cloud server 2 is powered on and a program for executing the channel determination process is started. First, the room map acquisition unit 211 determines whether or not it has acquired room map information from the management server 4 (step S101). If the room map acquisition unit 211 determines that it has not acquired room map information (step S101: No), it executes the process of step S103 described later. On the other hand, if the room map acquisition unit 211 determines that it has acquired room map information from the management server 4 (step S101: Yes), it stores the acquired room map information in the AP position information storage unit 231 (step S102). Next, the AP position information acquisition unit 212 determines whether or not it has acquired AP position information including the SSID information of the control device 1 and the room identification information of the rooms S11, S12, ..., S33 in which the control device 1 is installed from the management server 4 (step S103). If the AP position information acquisition unit 212 determines that the AP position information has not been acquired (step S103: No), the process of step S105 described below is executed. On the other hand, if the AP position information acquisition unit 212 determines that the AP position information has been acquired from the management server 4 (step S103: Yes), the AP position information acquisition unit 212 stores the acquired AP position information in the AP position information storage unit 231 (step S104).

Then, the AP information acquisition unit 213 determines whether or not a preset channel update time has arrived based on the time measured by the clock unit 207 (step S105). The AP information acquisition unit 213 determines whether or not a preset channel update time has arrived (step S105). If the AP information acquisition unit 213 determines that the channel update time has arrived (step S105: Yes), the process of step S107 described below is executed. On the other hand, if the AP information acquisition unit 213 determines that the channel update time has not yet arrived (step S105: No), the channel update request acquisition unit 225 determines whether or not it has acquired channel update request information transmitted from the control device 1 (step S106). If the channel update request acquisition unit 225 determines that it has not acquired channel update request information (step S106: No), the process of step S101 is executed again.

On the other hand, when the channel update request acquisition unit 225 determines that the channel update request information has been acquired (step S106: Yes), it notifies the AP information acquisition unit 213 of the acquired channel update request information. Then, the AP information acquisition unit 213 acquires AP information transmitted from the control device 1 by transmitting the above-mentioned AP information request information to a plurality of control devices 1 (step S107) (step S108). Here, the AP information acquisition unit 213 notifies the AP identification information extraction unit 214, the radio wave strength extraction unit 215, and the self-utilization rate extraction unit 218 of the acquired AP information. Then, the AP identification information extraction unit 214 extracts the SSID information of the control device 1 contained in the AP information (step S109). Here, the AP identification information extraction unit 214 notifies the impact coefficient calculation unit 216 of the extracted SSID information. Next, the radio wave strength extraction unit 215 extracts the radio wave strength information contained in the AP information (step S110). Here, the signal strength extraction unit 215 notifies the extracted signal strength information to the influence coefficient calculation unit 216. Next, the own utilization rate extraction unit 218 extracts the own utilization rate information included in the AP information (step S111). Here, the own utilization rate extraction unit 218 stores the extracted own utilization rate information in the own utilization rate storage unit 234.

Then, the influence coefficient calculation unit 216 calculates the influence coefficient for each of the multiple control devices 1 (step S112). Here, for example, as shown in FIG. 11 (A), control devices 1 with SSID11, SSID12, SSID21, and SSID22 are installed in four rooms S11, S12, S21, and S22, respectively. Then, in the control devices 1 installed in the rooms S11, S12, S21, and S22, the radio wave strength coming from the other control devices 1 is in a state as shown in FIG. 11 (B), for example. In FIG. 11 (B), "radio wave strength" represents the radio wave strength coming from the other control devices 1 with the SSID shown in the "SSID of surrounding AP" column in the control device 1 with the SSID shown in the "SSID" column. Here, the influence coefficient calculation unit 216 sets the influence coefficient to "1.0" if the radio wave strength of the radio wave arriving from another control device 1 is equal to or greater than the reference radio wave strength, and sets the influence coefficient to "0" if it is less than the reference radio wave strength, and also sets the reference radio wave strength to "-60 dBm." In this case, the influence coefficients corresponding to each combination of two control devices 1 are as shown in the "Influence coefficient" column of FIG. 11(B). Then, the influence coefficient calculation unit 216 assigns coefficient identification information, for example as shown in the "Coefficient identification information" column of FIG. 11(B), to each calculated influence coefficient.

12, the surrounding congestion degree calculation unit 217 calculates the product of the self-usage rate of each of the multiple channels and the influence coefficient for the other control devices 1, and calculates the sum of the calculated products as the surrounding congestion degree (step S113). The surrounding congestion degree calculation unit 217 stores surrounding congestion degree information indicating the calculated surrounding congestion degree in the surrounding congestion degree storage unit 233. Next, the channel usage rate calculation unit 219 calculates the channel usage rate of each of the multiple channels for each combination of multiple types of channels that can be used by each of the multiple access points based on the self-usage rate of each of the multiple access points, the surrounding congestion degree at each of the multiple access points, and the influence coefficient (step S114).

Then, the maximum value calculation unit 220 calculates the maximum value of the channel usage rate for each combination of the multiple types of channels (step S115). Here, the maximum value calculation unit 220 stores maximum value information indicating the calculated maximum value of the channel usage rate in the channel combination storage unit 241 in association with the combination of the multiple types of channels. Next, the average value calculation unit 221 calculates the average value of the channel usage rate for each combination of the multiple types of channels (step S116). Here, the average value calculation unit 221 stores average value information indicating the calculated average value in the channel combination storage unit 241 in association with the combination of the multiple types of channels. Next, the standard deviation calculation unit 222 calculates the standard deviation of the channel usage rate for each combination of the multiple channels (step S117). Here, the standard deviation calculation unit 222 stores standard deviation information indicating the calculated standard deviation in the channel combination storage unit 241 in association with the combination of the multiple types of channels. For example, as shown in FIG. 11A, control devices 1 with SSID11, SSID12, SSID13, and SSID14 are installed in four rooms S11, S12, S21, and S22, respectively, and the influence coefficients corresponding to each combination of two control devices 1 are set as shown in FIG. 11B. In this case, if the self-utilization rates of the control devices 1 installed in each room S11, S12, ..., S33 are all "10%, the channel utilization rates, their average values, their standard deviations, and their maximum values corresponding to each combination of channels used by the control devices 1 installed in each room S11, S12, ..., S33 will be the values shown in FIG. 13.

Then, the selection unit 223 executes a channel selection process to select one channel combination from among multiple types of channel combinations (step S118). Here, the details of the channel selection process will be described with reference to FIG. 14. First, the selection unit 223 selects a channel combination with the smallest maximum channel usage rate from among multiple types of channel combinations (step S201). For example, in the case of the example shown in FIG. 13, the selection unit 223 selects a combination in which the control devices 1 installed in the rooms S11, S12, S21, and S22 use channels CHa, CHb, CHb, and CHa, respectively, and a combination in which channels CHb, CHa, CHa, and CHb are used. Returning to FIG. 14, next, the selection unit 223 determines whether there are multiple channel combinations with the smallest maximum channel usage rate (step S202). Here, when the selection unit 223 determines that there is only one combination of channels with the smallest maximum value of the selected channel usage rate (step S202: No), it stores channel information indicating the combination of selected channels in the channel information storage unit 235. Then, the process of step S119 shown in FIG. 12 is performed. On the other hand, as shown in FIG. 14, when the selection unit 223 determines that there are multiple combinations of channels with the smallest maximum value of the selected channel usage rate (step S202: Yes), it selects a combination of channels with the smallest average value of the channel usage rate from the multiple types of channel combinations (step S203). Next, the selection unit 223 determines whether there are multiple combinations of channels with the smallest average value of the selected channel usage rate (step S204). Here, when the selection unit 223 determines that there is only one combination of channels with the smallest average value of the selected channel usage rate (step S204: No), it stores channel information indicating the combination of selected channels in the channel information storage unit 235. Then, the process of step S119 shown in FIG. 12 is performed. On the other hand, as shown in FIG. 14, when the selection unit 223 determines that there are a plurality of channel combinations with the smallest average value of the selected channel usage rates (step S204: Yes), the selection unit 223 selects at least one channel combination with the smallest standard deviation of the channel usage rates (step S205). After that, the selection unit 223 determines whether there are a plurality of channel combinations with the smallest standard deviation of the selected channel usage rates (step S206). Here, when the selection unit 223 determines that there is only one channel combination with the smallest standard deviation of the selected channel usage rates (step S206: No), the channel information indicating the selected channel combination is stored in the channel information storage unit 235. Then, the process of step S119 shown in FIG. 12 is performed. On the other hand, as shown in FIG. 14, when the selection unit 223 determines that there are multiple channel combinations that have the smallest standard deviation of the selected channel usage rates (step S206: Yes), the selection unit 223 selects one channel combination from the selected channel combinations (step S207). Then, the selection unit 223 stores channel information indicating the selected channel combination in the channel information storage unit 235.

Returning to FIG. 12, next, the channel information transmission unit 224 transmits to the multiple control devices 1 channel information stored in the channel information storage unit 235 indicating the combination of channels used by each of the multiple control devices 1 (step S119). Next, the process of step S101 is executed again.

As described above, according to the cloud server 2 of this embodiment, the channel usage rate calculation unit 219 calculates the channel usage rate of each of the multiple channels for each combination of multiple types of channels that can be used by each of the multiple control devices 1 based on the self usage rate, surrounding congestion degree, and influence coefficient of each of the multiple control devices 1. Then, the maximum value calculation unit 220 calculates the maximum value of the channel usage rate for each combination of multiple types of channels, and the selection unit 223 selects the channel combination with the smallest maximum channel usage rate from the combination of multiple types of channels. This makes it possible to set the channel combination used by each of the multiple control devices 1 so that the usage rate of each channel is uniform and low, thereby suppressing a decrease in communication speed caused by an imbalance in the channels used.

As shown in FIG. 1, when nine control devices 1 installed in nine rooms S11, S12, ..., S33 are arranged in such a way that their wireless communication areas interfere with each other, each of the multiple control devices 1 selects an optimal channel based on the busy occurrence rate. For example, when an access point adopts the communication protocol IEEE802.11b, it is common to use one of four channels that do not overlap in frequency bands among 14 channels whose center frequencies are set at intervals of about 5 MHz and whose frequency bandwidth is 22 MHz. In this case, when nine control devices 1 installed in such a way that their wireless communication areas interfere with each other as shown in FIG. 1 communicate using four channels, the number of control devices 1 is greater than the number of channels, so that the channels used by the multiple control devices 1 are concentrated on one of the four channels, and the communication speed of the control device 1 using that channel may decrease. In contrast, the cloud server 2 according to the present embodiment can set the combination of channels used by each of the multiple control devices 1 so that the usage rate of each channel is uniform and low, and can prevent the channels used by the nine control devices 1 from concentrating on one channel and distribute them among four channels. Therefore, the usage rate of each channel to one channel can be reduced, and the decrease in communication speed of each control device 1 can be reduced accordingly.

The cloud server 2 according to this embodiment also includes an average calculation unit 221 that calculates the average channel usage rate for each combination of multiple types of channels. If there are multiple channel combinations with the smallest maximum value among the combinations of multiple types of channels, the selection unit 223 selects the channel combination with the smallest maximum value and the smallest average value. This makes it possible to set the channel combinations used by each of the multiple control devices 1 so that the average usage rate of each channel is low, thereby suppressing the occurrence of busy states on each channel and suppressing a decrease in communication speed.

Furthermore, the cloud server 2 according to this embodiment includes a standard deviation calculation unit 222 that calculates the standard deviation of the channel usage rate for each combination of multiple types of channels. Then, when there are multiple channel combinations with the smallest maximum value and the smallest average value among the combinations of multiple types of channels, the selection unit 223 selects one channel combination from at least one channel combination with the smallest maximum value, the smallest average value, and the smallest standard deviation. This makes it possible to set the channel combinations used by each of the multiple control devices 1 so that the variation in the usage rate of each channel is small, and therefore the variation in the communication speed of each channel can be suppressed accordingly.

The influence coefficient calculation unit 216 according to this embodiment also calculates the influence coefficient for each of the multiple access points based on the radio wave strength of the radio waves transmitted from the other access points. This allows the influence coefficient to be calculated with high accuracy.

Furthermore, the control device 1 according to this embodiment includes a determination unit 121 that determines whether the busy occurrence rate is equal to or greater than the aforementioned reference busy occurrence rate, and a channel update request unit 122 that transmits the aforementioned channel update request information to the cloud server 2 when it is determined that the busy occurrence rate is equal to or greater than the reference busy occurrence rate. Then, when the channel update request acquisition unit 225 acquires the channel update request information, the AP information acquisition unit 213 acquires AP information from the multiple control devices 1, and the influence coefficient calculation unit 216 calculates the influence coefficient based on the SSID information and radio wave strength information included in the AP information. As a result, when the busy occurrence frequency increases in the control device 1 and the communication speed decreases, the busy occurrence frequency can be immediately updated to reduce the communication speed decrease, thereby preventing the communication speed from continuing to decrease.

Although the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-mentioned embodiment. For example, as in the cloud server 2002 shown in FIG. 15, the influence coefficient calculation unit 2216 may calculate the influence coefficient based on the arrangement of the rooms S11, S12, ..., S33 indicated by the room map information and the SSID information of the control device 1 installed in each room S11, S12, ..., S33. Here, the influence coefficient calculation unit 2216 may set the influence coefficient corresponding to the other control device 1 installed in the room adjacent to the above, below, left, and right to "1" for each of the multiple control devices 1, and set the influence coefficient of the other control device 1 installed in the room located diagonally to "0" since the radio wave intensity of the radio wave coming from there is sufficiently low and has little influence. Note that the influence coefficient calculation unit 2216 may set the influence coefficient corresponding to the other control device 1 installed in the room adjacent to the above, below, left, and right to a value greater than 0 and less than 1 based on information indicating the material or thickness of the wall between the room.

The influence coefficient calculation unit 2216 may set to "0" the influence coefficients corresponding to other control devices 1 that are located in the up, down, left, and right directions as viewed from the room in which the control device 1 for which the influence coefficient is to be calculated is installed, and that are located in a room with two or more rooms between them and the room in which the control device 1 for which the influence coefficient is to be calculated is installed. Furthermore, the influence coefficient calculation unit 2216 may set the influence coefficients corresponding to other control devices 1 that are located in the up, down, left, and right directions as viewed from the room in which the control device 1 for which the influence coefficient is to be calculated is installed, and that are located in a room with only one room between them and the room in which the control device 1 for which the influence coefficient is to be calculated is installed, to "1" if the distance between the two rooms is less than a preset reference distance based on the room map information, and to "0.5" if the distance is equal to or greater than the reference distance.

With this configuration, the influence coefficient calculation unit 2216 can calculate the influence coefficient without using radio wave intensity information, which makes the radio wave intensity extraction unit 215 described in the embodiment unnecessary, and has the advantage of reducing the processing load on the cloud server 2 accordingly.

In the embodiment, an example has been described in which the influence coefficient calculation unit 216 sets the influence coefficient to "1.0" if the radio wave strength of the radio wave arriving from another control device 1 is equal to or greater than the reference radio wave strength, and sets the influence coefficient to "0" if the radio wave strength is less than the reference radio wave strength. However, this is not limited to this, and the influence coefficient calculation unit 216 may calculate the influence coefficient by comparing the radio wave strength of the radio wave arriving from another control device 1 with multiple types of reference radio wave strengths. For example, the influence coefficient calculation unit 216 may set the influence coefficient to "1.0" if the radio wave strength of the radio wave arriving from another control device 1 is equal to or greater than a first reference radio wave strength set in advance, set the influence coefficient to "0.5" if the radio wave strength is less than the first reference radio wave strength and equal to or greater than a second reference radio wave strength that is smaller than the first reference radio wave strength, and set the influence coefficient to "0" if the radio wave strength is less than the second reference radio wave strength.

In the embodiment, as shown in FIG. 1, only one router 8 and one line termination device 9 are connected to the local network NW2 between each room S11, S12, ..., S33 and the wide area network NW1, i.e., one each is provided for the entire apartment building. However, this is not limited to this, and one router and one line termination device may be provided for each room S11, S12, ..., S33. In this case, each router may be provided independently in each room S11, S12, ..., S33, or may be provided in a control device 1 installed in each room S11, S12, ..., S33. Each router may be directly connected to the wide area network NW1.

The various functions of the control device 1 and cloud server 2 according to the present disclosure may be realized by software, firmware, or a combination of software and firmware. In this case, the software or firmware may be written as a program, and the program may be stored and distributed on a computer-readable recording medium such as a flexible disk, a CD-ROM (Compact Disc Read Only Memory), a DVD (Digital Versatile Disc), or an MO (Magneto-Optical Disc), and the program may be read and installed on a computer to configure a computer capable of realizing each of the above-mentioned functions. In addition, when each function is realized by sharing the work between an OS (Operating System) and an application, or by cooperation between an OS and an application, only the parts other than the OS may be stored on the recording medium.

Furthermore, each program can be superimposed on a carrier wave and distributed via a communication network. For example, the program can be posted on a bulletin board (BBS, Bulletin Board System) on the communication network and distributed via the network. These programs can then be started and run under the control of the OS in the same way as other application programs, thereby enabling the above-mentioned processing to be performed.

This disclosure is suitable as a system for optimizing the channels used by each access point installed in an apartment building.

1 Control device, 2, 2002 Cloud server, 3 Equipment, 4 Management server, 8 Router, 9 Line termination device, 101, 201 CPU, 102, 202 Main memory unit, 103, 203 Auxiliary memory unit, 106 Wireless module, 107 Wired communication interface, 109, 209 Bus, 111 Beacon information acquisition unit, 112 AP identification information storage unit, 113 Radio wave intensity acquisition unit, 114 Busy state detection unit, 115 Occurrence rate calculation unit, 116 Communication control unit, 117 Usage rate calculation unit, 118 AP information generation unit, 119 AP information transmission unit, 120 Channel information acquisition unit, 121 Determination unit, 122 Channel update request unit, 131 Surrounding AP information storage unit, 132 Occurrence rate storage unit, 133 Usage rate storage unit, 134 Channel storage unit, 207 Timer, 208 Wide area communication, 211 Room map acquisition, 212 AP position information acquisition, 213 AP information acquisition, 214 AP identification information extraction, 215 Radio wave intensity extraction, 216, 2216 Influence coefficient calculation, 217 Surrounding congestion calculation, 218 Self-utilization rate extraction, 219 Channel utilization rate calculation, 220 Maximum value calculation, 221 Average value calculation, 222 Standard deviation calculation, 223 Selection, 224 Channel information transmission, 225 Channel update request acquisition, 231 AP position information storage, 232 Influence coefficient storage, 233 Surrounding congestion storage, 234 Self-utilization rate storage, 235 Channel information storage, 241 Channel combination storage, NW1 Wide area network, NW2 Local network

Claims (8)

A channel determination device that determines a channel to be used by each of a plurality of access points from a plurality of preset channels,
an influence coefficient calculation unit that calculates, for each of the plurality of access points, an influence coefficient indicating a degree of influence of a communication state of each of the plurality of access points on a communication state of the other access points;
a channel usage rate calculation unit that calculates a channel usage rate of each of the plurality of channels for each combination of a plurality of types of channels that can be used by each of the plurality of access points, based on a self usage rate indicating a usage rate of each of the plurality of channels for each of the plurality of access points, a surrounding congestion degree that reflects a usage state of each of the plurality of channels by other access points at each of the plurality of access points, and the influence coefficient;
a maximum value calculation unit that calculates a maximum value of the channel usage rate for each combination of the plurality of types of channels;
a selection unit that selects the channel combination that minimizes the maximum value from among the plurality of types of channel combinations.
Channel determination device. an average value calculation unit that calculates an average value of the channel usage rate for each combination of the plurality of types of channels;
the selection unit, when there are a plurality of channel combinations with the smallest maximum value among the plurality of types of channel combinations, selects the channel combination with the smallest maximum value and the smallest average value.
2. The channel determination device according to claim 1. a standard deviation calculation unit that calculates a standard deviation of the channel usage rate for each combination of the plurality of types of channels,
the selection unit, when there are a plurality of channel combinations in which the maximum value and the average value are smallest among the plurality of types of channel combinations, selects one of the channel combinations in which the maximum value, the average value, and the standard deviation are smallest from at least one of the channel combinations in which the maximum value, the average value, and the standard deviation are smallest.
3. The channel determination device according to claim 2. the influence coefficient calculation unit calculates the influence coefficient for each of the plurality of access points based on the radio wave intensity of radio waves transmitted from each of the plurality of access points;
A channel determination device according to any one of claims 1 to 3. Multiple access points;
a channel determination device that determines a channel to be used by each of the plurality of access points from among a plurality of preset channels;
The channel determination device comprises:
an influence coefficient calculation unit that calculates, for each of the plurality of access points, an influence coefficient indicating a degree of influence of a communication state of each of the plurality of access points on a communication state of the other access points;
a channel usage rate calculation unit that calculates a channel usage rate of each of the plurality of channels for each combination of a plurality of types of channels that can be used by each of the plurality of access points, based on a self usage rate indicating a usage rate of each of the plurality of channels for each of the plurality of access points, a surrounding congestion degree that reflects a usage state of each of the plurality of channels by other access points at each of the plurality of access points, and the influence coefficient;
a maximum value calculation unit that calculates a maximum value of the channel usage rate for each combination of the plurality of types of channels;
a selection unit that selects, from among the plurality of types of channel combinations, the channel combination that minimizes the maximum value,
Channel determination system. At least one of the plurality of access points is
an occurrence rate calculation unit for calculating a busy occurrence rate, which is an occurrence rate of a busy state;
a determination unit that determines whether the busy occurrence rate is equal to or greater than a preset reference busy occurrence rate;
a channel update request unit that transmits, when it is determined that the busy occurrence rate is equal to or greater than the reference busy occurrence rate, channel update request information that requests the channel determination device to update the channels used by the plurality of access points, to the channel determination device;
The channel determination device comprises:
A channel update request acquisition unit that acquires the channel update request information,
When the channel update request acquisition unit acquires the channel update request information, the influence coefficient calculation unit calculates the influence coefficient, and the channel usage rate calculation unit calculates the channel usage rate.
6. The channel determination system according to claim 5. A channel determination method in which a channel determination device determines a channel to be used by each of a plurality of access points from a plurality of preset channels, the method comprising:
calculating an influence coefficient for each of the plurality of access points, the influence coefficient indicating a degree of influence of a communication state of each of the plurality of access points on a communication state of the other access points;
calculating a channel usage rate of each of the plurality of channels for each combination of a plurality of types of channels that can be used by each of the plurality of access points based on a self usage rate indicating a usage rate of each of the plurality of channels for each of the plurality of access points, a surrounding congestion degree reflecting a usage state of each of the plurality of channels by other access points at each of the plurality of access points, and the influence coefficient;
calculating a maximum value of the channel usage rate for each combination of the plurality of types of channels;
selecting, from among the plurality of types of channel combinations, the channel combination that minimizes the maximum value,
How to determine the channel. Computer,
an influence coefficient calculation unit that calculates, for each of a plurality of access points, an influence coefficient indicating a degree of influence of a communication state of each of the plurality of access points on a communication state of the other access points;
a channel usage rate calculation unit that calculates a channel usage rate of each of a plurality of channels for each combination of a plurality of types of channels that can be used by each of the plurality of access points, based on a self usage rate indicating a usage rate of each of a plurality of channels preset for each of the plurality of access points, a surrounding congestion degree that reflects a usage state of each of the plurality of channels by other access points at each of the plurality of access points, and the influence coefficient;
a maximum value calculation unit that calculates a maximum value of the channel usage rate for each combination of the plurality of types of channels;
a selection unit that selects, from among the plurality of types of channel combinations, the channel combination that minimizes the maximum value;
A program to function as a

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