JP7632620B2 - Wireless communication system, wireless communication method, access point device and program - Google Patents

Description

Embodiments of the present invention relate to a wireless communication system, a wireless communication method, an access point device and a program.

2. Description of the Related Art A wireless communication system including a base station and a terminal is known.
A representative example of a wireless communication system is a public wireless local area network (LAN). In a public wireless LAN, a use case is assumed in which data is transmitted from a base station to a public computer terminal and a public smartphone terminal.
Furthermore, with the recent spread of Internet of Things (IoT) terminals, the number of use cases in which data is transmitted from the terminal side is increasing.

As wireless communication for this IoT, wireless communication systems that use the Sub-1 GHz band, a frequency band that does not require a radio station license (unlicensed frequency band), have been institutionalized in various countries around the world. In Japan, the 920 MHz band has been allocated as a frequency band for electronic tag systems. Among these, so-called LPWA (Low Power Wide Area) wireless communication systems, such as LoRa (Long Range) or WiSUN (Wireless Smart Utility Network), are used as active electronic tag systems. The use of IEEE 802.11ah, a wireless LAN standard, is also being considered.

In this way, in order to allow different wireless communication systems to share the same frequency band and coexist with each other, several constraints are specified for the transmitting terminal. One of these constraints is the limit on the total transmission time (total transmission time limit).

This total transmission time limit stipulates the upper limit of the time during an hour that a data signal can be transmitted. For example, in the 920 MHz band, which is the frequency band used in Japan, the total transmission time limit is 360 seconds per hour. This limit is converted into a time rate, that is, the ratio of transmittable time to the total time, and is 10%.

Furthermore, this total transmission time restriction is stipulated to be relaxed to 720 seconds per hour only when a transmitting device switches between multiple different, i.e. non-overlapping, radio channels (sometimes called radio frequency channels, or simply channels), provided that the total transmission time, which is the sum of the transmission times on each channel, is kept within 360 seconds per hour.
This relaxation of the total transmission time limit is a measure to address the increased communication load on the parent station and on terminals relaying the communication network, which occurs when the number of terminals that are communication destinations increases.

IEEE 802.11ah, a wireless LAN standard for IoT, was developed by improving wireless LAN originally intended for large-volume data communication for IoT, and is expected to be used in use cases with high traffic loads even when the number of terminals is small. With the above-mentioned IEEE 802.11ah, technology that can relax the total transmission time limit is also expected from the perspective of increasing communication capacity.

ARIB STD-T108 1.3 edition, "920MHz-BAND TELEMETER, TELECONTROLAND DATA TRANSMISSION RADIO EQUIPMENT ARIB STANDARD", April 12, 2019 IEEE Std 802.11ah TM-2016 (IEEE Standard for Information technology - Telecommunications and information exchange between systems Local and metropolitan area networks - Specific requirements, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, Amendment 2: Sub 1 GHz License Exempt Operation, IEEE Computer Society, 7 December 2016

If the time percentage of the total transmission time limit mentioned above is set to 20%, control is required to switch between different channels while limiting the time percentage of each channel's total transmission time limit to 10%.

This invention has been made in light of the above-mentioned circumstances, and its object is to provide a wireless communication system device, a wireless communication method, an access point device and a program that make it possible to maximize the total transmission time of wireless signals and increase communication capacity.

A wireless communication system according to one embodiment of the present invention is a wireless communication system in which an access point device and a plurality of station devices perform wireless communication under an upper limit of communication speed based on a predetermined upper limit value of the transmission time between the access point device and each of the plurality of station devices on a wireless communication channel currently used between the access point device and the plurality of station devices, and the wireless communication system has a wireless communication control device that controls the wireless communication, the wireless communication control device including a monitoring unit that monitors the transmission time between the access point device and each of the plurality of station devices on the wireless communication channel currently used between the access point device and each of the plurality of station devices, and a transition processing unit that performs switching processing to a wireless communication channel to which the currently used wireless communication channel is to be transitioned when there is a device among the plurality of station devices whose transmission time monitored by the monitoring unit is predicted to reach the predetermined upper limit value.

A wireless communication method according to one embodiment of the present invention is a wireless communication method in which an access point device and a plurality of station devices perform wireless communication under an upper limit of communication speed based on a predetermined upper limit value of the transmission time between the access point device and each of the plurality of station devices in a wireless communication channel currently used between the access point device and the plurality of station devices, and the wireless communication is controlled by a wireless communication control device, the method comprising: a monitoring unit of the wireless communication control device monitors the transmission time between the access point device and each of the plurality of station devices in the wireless communication channel currently used between the access point device and the plurality of station devices; and a transition processing unit of the wireless communication control device performs switching processing to a wireless communication channel to which the currently used wireless communication channel is to be transitioned when there is a device among the plurality of station devices whose monitored transmission time is predicted to reach the predetermined upper limit value.

An access point device according to one embodiment of the present invention is an access point device of a wireless communication system that performs wireless communication with a plurality of station devices, wherein the wireless communication is performed under an upper limit of communication speed based on a predetermined upper limit value of the transmission time between the access point device and each of the plurality of station devices in a wireless communication channel currently used between the access point device and each of the plurality of station devices, and the access point device is equipped with a monitoring unit that monitors the transmission time between each of the plurality of station devices in the wireless communication channel currently used between the access point device and each of the plurality of station devices, and a transition processing unit that performs switching processing to a wireless communication channel to which the currently used wireless communication channel is to be transitioned when there is a device among the plurality of station devices whose transmission time monitored by the monitoring unit is predicted to reach the predetermined upper limit value.

According to the present invention, it is possible to maximize the total transmission time of radio signals and increase communication capacity.

FIG. 1 is a block diagram showing an example of the overall configuration of a wireless communication system according to an embodiment of the present invention. FIG. 2 is a block diagram showing an example of the hardware configuration of the wireless communication control device 10 in the wireless communication system. FIG. 3 is a diagram showing an example of the total transmission time of a radio frame depending on a channel transition in a wireless communication system. FIG. 4 is a block diagram showing a first example of a control function according to a wireless communication control program of the wireless communication control device. FIG. 5 is a flow chart showing a first example of a procedure of a control process by the wireless communication control device of the wireless communication system. FIG. 6 is a block diagram showing a second example of the control function according to the wireless communication control program of the wireless communication control device. FIG. 7 is a flowchart showing a second example of the procedure of the control process by the wireless communication control device of the wireless communication system. FIG. 8 is a flowchart showing a third example of a procedure of a control process by the wireless communication control device of the wireless communication system. FIG. 9 is a flowchart illustrating a fourth example of a procedure of a control process by a wireless communication control device in a wireless communication system.

Hereinafter, a wireless communication system, a wireless communication method, an access point device, and a program according to the embodiments will be described with reference to the drawings.
FIG. 1 is a block diagram showing an example of the overall configuration of a wireless communication system according to an embodiment of the present invention.
The wireless communication system of the embodiment has an AP (access point device) 1, which is a parent device of a wireless LAN, and multiple STAs (station devices) 2-1, 2-2, ..., 2-N, and one or multiple STAs 2-1, 2-2, ..., 2-N are connected to the AP 1 and communicate with each other. Hereinafter, STAs 2-1, 2-2, ..., 2-N may be collectively referred to simply as STA2.
Here, a cell consisting of AP1 and STAs 2-1, 2-2, . . . , 2-N is called a Basic Service Set (BSS).

In this embodiment, the total transmission time limit is relaxed by this BBS channel transition, i.e., the process of switching from the currently used wireless communication channel to another wireless communication channel to which it is to be transitioned.

The AP1 and the STAs 2-1, 2-2, ..., 2-N are connected to wireless communication control devices 20-1, 20-2, ..., 20-N, respectively, via a wired or wireless communication network. Hereinafter, the wireless communication control devices 20-1, 20-2, ..., 20-N may be collectively referred to simply as the wireless communication control devices 20. The wireless communication control devices 10, 20-1, 20-2, ..., 20-N each have a function of exchanging wireless environment information and control commands.
It should be noted that the wireless communication control apparatus 10 connected to the AP 1 does not need to be connected to the AP 1 as an external device of the AP 1 when the wireless communication control program is installed in the AP or STA.
Furthermore, if the STA is a relatively sophisticated device and has relatively ample computing capabilities, a wireless communication control device and its wireless communication control program may be installed in the STA rather than in the AP.

The control that determines the timing of channel transition also includes monitoring of the total transmission time. When monitoring of the total transmission time and control of the channel transition timing are performed together, the wireless communication control programs corresponding to the AP1 and each STA2-1, 2-2, ..., 2-N may operate independently while synchronizing between the wireless communication control devices 10, 20-1, 20-2, ..., 20-N, or when the wireless communication control programs are loaded into the AP1 and each STA2-1, 2-2, ..., 2-N, they may operate independently while synchronizing between the AP1 and each STA2-1, 2-2, ..., 2-N.

Also, the wireless communication control apparatus 10 connected to the AP 1 may operate to collectively manage and control even the total transmission time of each of the STAs 2-1, 2-2, . . . , 2-N.
In addition, when the wireless communication control device 10 connected to AP1 performs centralized monitoring of the wireless communication system and judges and determines the timing of channel transition (change), it controls the judgement and decision taking into account the transmission status of STAs and APs of other BBSs.

FIG. 2 is a block diagram showing an example of a hardware configuration of the wireless communication control device 10 in the wireless communication system.
The wireless communication control device 10 includes a control circuit (processor) 11 .
Connected to the control circuit 11 via a system and a data bus are a memory 12 such as a flash ROM, a hard disk drive 13 including a storage medium 13a such as a magnetic disk, a user interface 14 including keys, switches, and an external input terminal for a user to operate from the outside, a wired communication module 15 and/or a wireless communication module 16 for communicating with the outside, and a timer 17 that manages the time for which a channel is scanned, i.e., the channel transition time.

The control circuit 11 controls the operation of each part of the wireless communication control device 10 in accordance with the wireless communication control program stored in the control program area 12a of the memory 12, and based on the management information stored in or read from the management information area 12b of the memory 12.

The wireless communication control devices 20-1, 20-2, ..., 20-N that are paired with STA2-1, 2-2, ..., 2-N can also be configured with hardware similar to the wireless communication control device 10 of AP1 shown in Figure 2.

In addition, AP1, STA2-1, 2-2, ..., 2-N can basically be configured with hardware including a control circuit, memory, a user interface, a wired communication module and/or a wireless communication module, similar to the wireless communication control device 10 of AP1 shown in Figure 2.

And, when the wireless communication control program of the wireless communication control device 10 of AP1 is loaded in AP1, the wireless communication control program may be stored, for example, together with an AP control program for executing a predetermined operation of the AP (access point device) 1, which is stored in advance in a control program area of the memory in the AP1. In this case, the AP1 will have the function of the wireless communication control device 10 by itself.

In addition, when the wireless communication control program possessed by the wireless communication control devices 20-1, 20-2, ..., 20-N that correspond one-to-one to the STAs 2-1, 2-2, ..., 2-N is loaded into the STA, the wireless communication control program may be stored, for example, together with a STA control program for executing a predetermined operation as the STA (station device) 2 that is pre-stored in the control program area of the memory in the STA 2. In this case, the STA 2 will independently have the functions of the wireless communication control device 20.

FIG. 3 is a diagram illustrating an example of a total transmission time of wireless frames depending on a channel transition in a wireless communication system.
Channel transitions are necessary to avoid channels that are heavily used, to avoid interference with other radio signals, and to satisfy hourly total transmission time limitations imposed by radio wave-related laws and regulations.

Here, we assume that there are channels "1" and "2" as different non-overlapping channels, and that AP1 and STA2 perform a channel transition to switch the currently used channel to channel "1" or "2."

First, AP1 and STA2 communicate by exchanging wireless frames using channel "1." During this time, each wireless communication terminal transmits so that the total transmission time per hour does not exceed the limit value stipulated for one channel.
However, if transmission above the limit is required and a channel transition is required, it is decided to use channel "2" for transmission, and communication on channel "1" is stopped and communication is transitioned to channel "2" for communication.
After that, communication must be performed on channel "2" so as not to exceed the limit value stipulated for channel "1." Furthermore, control must be performed so that the total transmission time per hour transmitted on the two channels for each wireless communication terminal does not exceed the limit value.

This reduces the total transmission time per hour that the channel is used, but there is a period of time during which communication is not possible from the start of the channel transition (switching) until STA2 completes its connection to AP1 (channel transition time Tc).

FIG. 4 is a block diagram showing a first example of a control function according to a wireless communication control program of the wireless communication control apparatus 10. As shown in FIG.
As shown in FIG. 4, the wireless communication control device 10 includes a setting unit 10a, a determining unit 10b, a channel transition processing unit 10c, and a communication control unit 10d as functions executed by a control circuit 11 according to the wireless communication control program.

The setting unit 10a, for example, in cooperation with AP1, performs processing to set management information necessary for determining a channel transition schedule, such as available channels, timing for determining whether or not a channel transition is necessary (e.g., time and communication state), a reference value for determining whether or not a channel transition is necessary, and timing for starting channel switching (e.g., time), in response to operations from the user interface 14. This setting includes a default.

The determining unit 10b performs a determination process including determining whether a channel transition is necessary, determining the timing of channel switching, and determining the connection state with the STA2, based on the management information set by the setting unit 10a, for example.
The channel transition processing unit 10c performs channel transition processing in cooperation with the processing in the setting unit 10a and the determination unit 10b, for example. The operation of the communication control unit 10d will be described later.

In the wireless communication system configured in this manner, the control circuit of the wireless communication control device 10 controls the operation of each part in cooperation with AP1 and STA2 in accordance with the instructions written in the wireless communication control program, and the software and hardware operate in cooperation to realize the channel switching function as described in the operation explanation below.

Next, the operation of the wireless communication system according to the embodiment will be described, which is related to the determination of the channel switching timing.
FIG. 5 is a flowchart showing a first example of a procedure of a control process by the wireless communication control device 10 in the wireless communication system.
Here, a control process for determining the timing of periodic channel transition control will be described. In the following, the control will be described as being performed by each unit of the wireless communication control device 10, but when the functions of each unit of the wireless communication control device 10 are incorporated into the AP1, the control may be performed by the AP1.

First, the setting unit 10a of the wireless communication control device 10 sets the channel to be used in the BSS and the timing of the next channel transition, which is a transition to a predetermined channel, in the control program for use in scheduling subsequent channel transitions, and starts counting by the timer 17 (s11).

Next, the setting unit 10a sets an upper limit traffic rate between each terminal, i.e., STA2, and then the communication control unit 10d starts communication between each terminal (s12). This upper limit traffic rate is the upper limit of the data rate of transmission data, and the wireless communication control device 10 restricts transmission or sets the data rate so that packets are not transmitted at a data rate higher than this. At this time, the upper limit traffic rate is set in accordance with the laws and regulations of the frequency band to be used.
For example, if the total transmission time rate on a plurality of channels is 20%, this 20% is set as the upper limit traffic rate.
However, taking into consideration that a certain amount of time is required for a BSS channel transition, the above time rate may be set to less than 20% in order to reduce the frequency of channel transitions.

In this state, communication continues until the timer 17 notifies the user of the set timing for the next channel transition (s13).
Then, when the determination unit 10b determines that the timer 17 has notified the next channel transition timing (Yes in s14), the channel transition processing unit 10c starts the above channel transition processing (s15). When the transition to the new channel is completed by this processing, the process returns to s11, and the timer 17 starts counting again.

The channel transition timing must be set so that the total transmission time on one channel does not exceed a limit.
For example, if the limit on the total transmission time on one channel is 360 seconds per hour, i.e., if the time rate of the total transmission time on one channel is 10%, and the time rate of the total transmission time is raised to 20% by switching between two channels with a fixed upper traffic rate, the time that one channel can be used continuously will be limited to 30 minutes.

FIG. 6 is a block diagram showing a second example of the control function according to the wireless communication control program of the wireless communication control apparatus 10. In FIG.
In the example shown in FIG. 6, the wireless communication control device 10 includes a setting unit 10a, a judgment unit 10b, a channel transition processing unit 10c, a communication control unit 10d, and a channel monitoring unit 10e as functions executed by the control circuit 11 in accordance with the wireless communication control program.

FIG. 7 is a flowchart showing a second example of the procedure of the control process by the wireless communication control device 10 in the wireless communication system.
Here, a control process will be described in which the timing of channel transition control is determined while channels are monitored.

First, the setting unit 10a of the wireless communication control device 10 sets the channel to be used in the BBS and the timing of the next channel transition in the control program for use in the schedule of the subsequent channel transition, and starts counting by the timer 17 (s21). In this setting, a plurality of channels to be used for the channel transition are registered.
The count value of the timer 17 is used by the channel monitoring unit 10e to determine the monitoring period.
The monitoring period is a unit of time for monitoring whether the total transmission time of a transmitting terminal complies with laws and regulations.
For example, if the total transmission time is stipulated by law as "per hour," then this one hour will be the monitoring period.

Next, the setting unit 10a sets the upper limit traffic rate between each terminal, i.e., STA2, and the communication control unit 10d starts communication (s22). At this time, the upper limit traffic rate is set in accordance with the laws and regulations of the frequency band to be used. For example, if the time rate of the total transmission time on multiple channels is 20%, the upper limit traffic rate is set based on this 20%.

Next, the channel monitoring unit 10e resets the monitoring information, that is, the count value of the timer 17 and the record of past transmission times, and starts monitoring the transmission times of the transmitting terminals (s23).
During this monitoring, communication continues until the count value of the timer 17 from the start of monitoring reaches a value indicating the end of the monitoring period (s24).
However, if the judgment unit 10b judges that there is a transmitting terminal STA2 whose transmission time on the current channel is expected to exceed the legally stipulated upper limit of total transmission time per channel, i.e., the duty ratio (Yes in s25), the channel transition processing unit 10c starts the above-mentioned channel transition (s26).
When the transition to the new channel is completed by this process, the process returns to s21 and the timer 17 starts counting again.

On the other hand, when the transmission time on the current channel does not exceed the upper limit of the total transmission time, and the count value of the timer 17 reaches the value indicating the end of the monitoring period (Yes in s27), the process returns to s23, the channel monitoring unit 10e resets the monitoring information, and monitoring of the transmission time is restarted. If the determination in s27 is No, the process returns to s24.

FIG. 8 is a flowchart showing a third example of a procedure of a control process by the wireless communication control device of the wireless communication system.
Here, a control process will be described in which no upper limit on steady traffic is set, and the timing of channel transition control is determined while channels are monitored.
In this example, the upper limit traffic rate that is set during communication in the first example shown in FIG. 5 and the second example shown in FIG. 7 is not set.

Therefore, the maximum traffic that can be transmitted can be handled momentarily. On the other hand, if this state continues, the total transmission time will exceed the limit if communication continues, so transmission is temporarily stopped and controlled to wait until the next available time to transmit.

First, the setting unit 10a of the wireless communication control device 10 sets the channel to be used in the BBS and the timing of the next channel transition in the control program for use in the schedule of the subsequent channel transition, as in s21, and starts counting by the timer 17 (s31). In this setting, as in s21, a plurality of channels to be used for the channel transition are registered.
The count value of the timer 17 is used by the channel monitoring unit 10e to determine the monitoring period.

Next, the channel monitoring unit 10e resets the monitoring information in the same manner as in s24, and starts monitoring the transmission time of the transmitting terminal (s32).
During this monitoring, similarly to s24, communication continues until the count value of the timer 17 reaches a value indicating the end of the monitoring period (s33).
However, similarly to s25, if the judgment unit 10b judges that there is a transmitting terminal STA2 whose transmission time on the current channel is expected to exceed the legal upper limit of the total transmission time per channel, i.e., the duty ratio (Yes in s34), the judgment unit 10b further judges whether or not the transmitting terminal is a transmitting terminal whose transmission time on the current channel is expected to exceed the duty ratio, which is the legal upper limit of the total transmission time per two channels (s35).

If the answer is Yes in s35, the communication control unit 10d stops communication between AP1 and the corresponding expected transmitting terminal and continues communication between AP1 and other terminals until counting for the next monitoring period begins (s36).

Furthermore, if the judgment unit 10b judges that, in addition to the terminal for which communication has been stopped as described above, there is a transmitting terminal STA2 whose transmission time on the current channel is expected to exceed the duty ratio, which is the upper limit of the total transmission time per channel set by law (Yes in s37), then rather than stopping transmission as described above, it is determined that the channel being used should be transitioned, and the channel transition processing unit 10c initiates the above channel transition (s38), as in s26.

In addition, after s35 is judged as Yes, when the judgment unit 10b judges that, in addition to the transmitting terminal whose transmission time is expected to exceed the duty ratio, which is the upper limit of the total transmission time per two channels established in accordance with laws and regulations, there is another transmitting terminal whose transmission time is expected to exceed the duty ratio, which is the upper limit of the total transmission time per two channels established in accordance with laws and regulations, a channel transition may be performed in s38 without stopping communication in s36.

The transition in s38 is performed, for example, when the judgment unit 10b compares the "risk of a temporary interruption of communication due to a channel transition" with the "risk of stopping transmission of a terminal whose transmission time on the current channel is expected to exceed the upper limit of the total transmission time per channel so that the terminal is not allowed to communicate until the next monitoring period," and judges that the channel should be transitioned rather than stopping transmission by the terminal whose transmission time on the current channel is expected to exceed the upper limit of the total transmission time per channel.
When the transition to the new channel is completed in s38, the process returns to s31 and the timer 17 starts counting again.

On the other hand, as in s27, if the transmission time on the current channel does not exceed the upper limit of the total transmission time and the count value of timer 17 reaches the value that is the end timing of the monitoring period (Yes in s39), the process returns to s33, the channel monitoring unit 10e resets the monitoring information, and monitoring of the transmission time is restarted. If the determination in s39 is No, the process returns to s33.

Figure 9 is a flowchart showing a fourth example of the procedure of the control process by the wireless communication control device of the wireless communication system. Here, we explain the control process in which no upper limit on steady-state traffic is set for some channels, and the timing of channel transition control is determined while the channels are monitored.

In the third example shown in FIG. 8, there is a risk of transmission stopping after a burst of transmission has been performed.
In order to avoid this transmission stop, in this fourth example, as in the third example, after a burst-like transmission is performed with no upper limit traffic rate set, the traffic is limited so that the transmission time in the transition destination channel does not exceed the upper limit of the total transmission time, and when the monitoring period ends, the traffic limit is removed again and transmission is performed.

In the fourth example, first, the setting unit 10a of the wireless communication control device 10 sets the channel to be used in the BBS and the timing of the next channel transition in the control program for use in the schedule of the subsequent channel transition, similar to s31, and starts counting by the timer 17 (s41). In this setting, similar to s31, a plurality of channels to be used for the channel transition are registered.
As in the third example, the count value of the timer 17 is used by the channel monitoring unit 10e to determine the monitoring period.
Next, the channel monitoring unit 10e resets the monitoring information in the same manner as in s32, and starts monitoring the transmission time of the transmitting terminal (s42).

Next, the decision unit 10b decides whether or not the current channel is a channel for which the setting of an upper limit traffic rate is required (s43).
The criterion for the judgment in s43 is, for example, whether the current channel is the channel after a previous transition after a short transmission time, e.g., 30 minutes or less, on another channel has reached the upper limit of the total transmission time per hour.

When the determination unit 10b determines that the current channel is a channel for which the setting of an upper limit traffic rate is required (Yes in s43), the setting unit 10a sets the upper limit traffic rate for each terminal, and the communication control unit 10d starts communication (s44).
At this time, the upper limit traffic rate is set in accordance with the laws and regulations of the frequency band being used so that transmission is not interrupted.

For example, if a transmission equivalent to 10% of the total transmission time has already been performed on another channel for 10 minutes, the upper limit traffic rate on the current channel is set so that the time percentage of the total transmission time is 10% for 50 minutes.

During the monitoring started in s42, communication continues until the count value of timer 17 reaches the end of the monitoring period (s45), as in s33. However, a terminal for which a communication stop process (described later) has been performed will continue to stop communication until the next monitoring period.

However, as in s25, if the judgment unit 10b judges that there is a transmitting terminal STA2 whose transmission time on the current channel is expected to exceed the upper limit of the total transmission time per channel set by law, i.e., the duty ratio (Yes in s46), the judgment unit 10b judges whether or not the terminal is capable of stopping communication until the next monitoring period, for example, based on whether or not the terminal is currently communicating or the priority of the content of the communication by the terminal (s47).

When the determination in s47 is made based on the priority of the communication content, for example, if the communication content by the terminal is a video transmission that is inappropriate for interruption, it is determined that the communication stop process is not possible. Also, in s47, if the communication content by the terminal is a file transmission that is permitted to be temporarily interrupted, it is determined that the communication stop process is possible.

If s47 is judged as Yes, the communication control unit 10d performs a process of stopping communication between the AP1 and the terminal until the counting for the next monitoring period starts, and continues communication between the AP1 and the other terminal (s48).If s47 is judged as No, that is, if the communication stopping process until the next monitoring period is not possible, the channel transition processing unit 10c starts the above channel transition (s49).
When the transition to the new channel is completed in s49, the process returns to s41 and the timer 17 starts counting again.

On the other hand, when the transmission time on the current channel does not exceed the upper limit of the total transmission time, and the count value by timer 17 reaches the value indicating the end of the monitoring period (Yes in s50), the process returns to s42, where channel monitoring unit 10e resets the monitoring information and restarts monitoring of the transmission time. Also, in this return to s42, communication control unit 10d resumes communication of the transmitting terminal for which communication stop processing has been performed. If the determination in s50 is No, the process returns to s45.

As described above, in a wireless communication system according to one embodiment of the present invention, an access point device and multiple station devices perform wireless communication, and the system has a wireless communication control device that controls the wireless communication, and monitors the transmission time between the access point device and each of the multiple station devices on a wireless communication channel currently used between the access point device and the multiple station devices, and when there is a device among the multiple station devices whose monitored transmission time is predicted to reach a predetermined upper limit value, a switching process is performed to switch from the currently used wireless communication channel to a wireless communication channel to which it is to be transitioned, thereby making maximum use of the total transmission time of wireless signals and increasing communication capacity.

The methods described in each embodiment can be stored as a program (software means) that can be executed by a computer on a recording medium such as a magnetic disk (floppy disk, hard disk, etc.), optical disk (CD-ROM, DVD, MO, etc.), semiconductor memory (ROM, RAM, flash memory, etc.), and can be distributed by transmission via a communication medium. The programs stored on the medium also include a setting program that configures the software means (including not only execution programs but also tables and data structures) that the computer executes. The computer that realizes this device reads the program recorded on the recording medium, and in some cases, constructs the software means using the setting program, and executes the above-mentioned processing by controlling the operation of the software means. The recording medium referred to in this specification is not limited to a recording medium for distribution, but also includes a storage medium such as a magnetic disk or semiconductor memory provided inside the computer or in a device connected via a network.

Note that the present invention is not limited to the above-described embodiments, and can be modified in various ways in the implementation stage without departing from the gist of the invention. The embodiments may also be implemented in appropriate combination, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combinations selected from the multiple constituent elements disclosed. For example, if the problem can be solved and an effect can be obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiments, the configuration from which these constituent elements are deleted can be extracted as an invention.

1...AP (Access Point Device)
2-1 to 2-N...STA (Station equipment)
Reference Signs List 10, 20-1 to 20N... Wireless communication control device 11... Control circuit 12... Memory 12a... Control program area 12b... Management information area 13... Disk drive 13a... Storage medium 14... User interface 15... Wired communication module 16... Wireless communication module 17... Timer

Claims (8)

1. A wireless communication system comprising an access point device and a plurality of station devices, performing wireless communication under an upper limit of communication speed based on a preset upper limit value of a transmission time between the access point device and each of the plurality of station devices in a wireless communication channel currently used between the access point device and the plurality of station devices , and a wireless communication control device for controlling the wireless communication,
The wireless communication control device includes:
a monitoring unit that monitors a transmission time between the access point device and each of the plurality of station devices in a wireless communication channel currently used between the access point device and each of the plurality of station devices;
a transition processing unit that performs a switching process of the currently used wireless communication channel to a wireless communication channel to be a transition destination when there is a device among the plurality of station devices whose transmission time monitored by the monitoring unit is predicted to reach the preset upper limit value;
A wireless communication system comprising: The wireless communication control device includes:
a communication control unit that, when there is a device among the plurality of station devices whose transmission time monitored by the monitoring unit within a predetermined time is predicted to reach a preset upper limit value per one wireless communication channel and when the device is a device whose transmission time monitored by the monitoring unit is predicted to reach preset upper limit values per two wireless communication channels, stops communication with the device.
2. The wireless communication system according to claim 1. The transition processing unit:
performing a switching process to a wireless communication channel to which the currently used wireless communication channel is to be transitioned when there is a device among the plurality of station devices, the transmission time monitored by the monitoring unit of which is predicted to reach a preset upper limit value per wireless communication channel, the device being a device whose transmission time monitored by the monitoring unit of which is predicted to reach a preset upper limit value per two wireless communication channels, and when there is a device among the station devices other than the device among which there is a device whose transmission time monitored by the monitoring unit of which is predicted to reach a preset upper limit value per wireless communication channel;
3. The wireless communication system according to claim 2. The wireless communication control device includes:
a determination unit that determines whether or not a currently used wireless communication channel should be a wireless communication channel for which an upper limit of communication speed is set based on the transmission time monitored by the monitoring unit;
a setting unit that sets an upper limit of a communication speed for a wireless communication channel when the determining unit determines that the currently used wireless communication channel should be a wireless communication channel for which an upper limit of a communication speed is to be set;
a communication control unit that stops communication with a device when the transmission time monitored by the monitoring unit is predicted to reach a preset upper limit value among the plurality of station devices and communication with the device can be stopped;
Further equipped with
The transition processing unit:
performing a switching process for switching the currently used wireless communication channel to a wireless communication channel to be a transition destination when there is a device among the plurality of station devices whose transmission time monitored by the monitoring unit is predicted to reach a preset upper limit value and when it is not possible to stop communication with the device;
2. The wireless communication system according to claim 1. 1. A wireless communication method in which an access point device and a plurality of station devices perform wireless communication under an upper limit of communication speed based on a preset upper limit value of a transmission time between the access point device and each of the plurality of station devices in a wireless communication channel currently used between the access point device and the plurality of station devices , and the wireless communication is controlled by a wireless communication control device,
monitoring, by a monitoring unit of the wireless communication control device, a transmission time between the access point device and each of the plurality of station devices in a wireless communication channel currently used between the access point device and each of the plurality of station devices;
a transition processing unit of the wireless communication control device, when there is a device among the plurality of station devices whose monitored transmission time is predicted to reach the preset upper limit value, performing a switching process to a wireless communication channel which is a transition destination of the currently used wireless communication channel;
A wireless communication method comprising: An access point device of a wireless communication system that performs wireless communication with a plurality of station devices,
the wireless communication is performed under an upper limit of communication speed based on a preset upper limit value of a transmission time between the access point device and each of the plurality of station devices in a wireless communication channel currently used between the access point device and each of the plurality of station devices,
a monitoring unit that monitors a transmission time between each of the plurality of station devices in a wireless communication channel currently used between the plurality of station devices;
a transition processing unit that performs a switching process of the currently used wireless communication channel to a wireless communication channel to be a transition destination when there is a device among the plurality of station devices whose transmission time monitored by the monitoring unit is predicted to reach the preset upper limit value;
An access point device comprising: a communication control unit that, when there is a device among the plurality of station devices whose transmission time monitored by the monitoring unit within a predetermined time is predicted to reach a preset upper limit value per one wireless communication channel and when the device is a device whose transmission time monitored by the monitoring unit is predicted to reach preset upper limit values per two wireless communication channels, stops communication with the device.
The access point device according to claim 6 . A program that causes a processor to function as each unit of the access point device according to claim 6 or 7.

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