JP2020195121A - Base station, terminal, communication system, communication method, and program - Google Patents

Abstract

To continue data transmission properly in a communication band where transmission time is limited for each communication channel.SOLUTION: A base station A1 performing radiocommunication with a terminal by using a communication band where the time capable of transmitting a communication frame is limited for each communication channel includes a wireless IF11 performing radiocommunication, an acquisition part 12 for acquiring a first time, i.e., a cumulative time when the terminal transmitted a communication frame by radiocommunication within a prescribed period where the present time is the end, and a second time, i.e., a cumulative time when the wireless IF11 transmitted the communication frame within a prescribed period, a communication unit 13 for transmitting a notification indicating to change the communication channel of the wireless IF11 to the terminal by the wireless IF11, when a determination is made that at least one of the first and second times, acquired by the acquisition part 12, has exceeded a prescribed threshold level, and a control section 14 for changing the communication channel of the wireless IF11 when the communication unit 13 transmitted the notification.SELECTED DRAWING: Figure 1

Description

The present invention relates to base stations, terminals, communication systems, communication methods, and programs.

In recent years, LPWA (Low Power Wide Area) has become widespread as a wireless communication method using the 920 MHz band. One of the communication standards belonging to LPWA is the IEEE802.11ah standard.

Here, the 920 MHz band used in the IEEE802.11ah standard is different from the IEEE802.11a, b, g, n, ac standard, etc., which uses the 2.4 GHz or 5 GHz band, and depending on the conditions of frequency and carrier sense time. The total transmission time is regulated by the Radio Law. One of its purposes is the fair use of radio bands. Therefore, when the communication device continuously transmits data, transmits a large amount of data, or the like, it may be necessary to stop the transmission even during the data transmission.

In this way, communication standards with total transmission time restrictions such as the IEEE802.11ah standard are compared with communication standards without total transmission time restrictions such as the IEEE802.11a, b, g, n, and ac standards. Therefore, the use of communication is limited. For example, it can be said that the IEEE802.11ah standard is unsuitable for applications that require continuous maintenance of a relatively high amount of communication, such as transfer of surveillance camera images.

Patent Document 1 discloses a network system capable of efficiently transmitting data so as to satisfy the limitation of data transmission time in communication in the 920 MHz band.

Japanese Unexamined Patent Publication No. 2015-15703

When data is transmitted in a communication band such as the 920 MHz band in which the transmission time is limited for each communication channel, there is a problem that it is difficult to transmit data in an amount exceeding the limit value.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a base station or the like capable of appropriately continuing data transmission in a communication band in which a transmission time is limited for each communication channel.

In order to solve the above problems, the base station according to one aspect of the present invention is a base station that wirelessly communicates with a terminal using a communication band in which the time during which a communication frame can be transmitted is limited for each communication channel. , The communication interface for wireless communication, the first time which is the cumulative time when the terminal transmits the communication frame by wireless communication within the predetermined period ending at the present time, and the communication interface within the predetermined period. When it is determined that at least one of the acquisition unit that acquires the second time, which is the cumulative time transmitted, and the first time and the second time acquired by the acquisition unit exceeds a predetermined threshold value, the communication interface. It is provided with a notification unit that transmits a notification indicating that the communication channel of the communication interface is changed to the terminal by the communication interface, and a control unit that changes the communication channel of the communication interface when the notification unit transmits the notification. ..

According to this, when the cumulative transmission time of at least one of the terminal and the base station approaches the limit value for each communication channel, the base station both the terminal and the base station change the communication channel. At this time, since the notification for notifying the channel change is transmitted to the terminal, the terminal can change the communication channel more reliably. Further, since the terminal can know the communication channel of the change destination by the notification, the communication can be started on the communication channel of the change destination without requiring the terminal to scan the communication channel to search for the base station. In this way, the base station can appropriately continue data transmission in the communication band in which the transmission time is limited for each communication channel.

Further, the acquisition unit acquires the first time by receiving the communication frame including the first time calculated by the terminal, and transmits the communication frame performed by the communication interface within the predetermined period. It is acquired by calculating the second time based on the information regarding.

According to this, the base station uses the value calculated by the transmitting terminal itself for the cumulative transmission time (first time) of the terminal, and determines relatively accurately that the cumulative transmission time has approached the limit value. can do. Further, regarding the cumulative transmission time (second time) of the base station, it is possible to relatively accurately determine that the cumulative transmission time has approached the limit value by using the value calculated by the transmitting base station itself. Therefore, the base station can appropriately continue data transmission by making a determination based on a more accurate cumulative transmission time in a communication band in which the transmission time is limited for each communication channel.

Further, the acquisition unit acquires the first time by calculating the first time based on the information regarding the reception of the communication frame transmitted by the terminal by the communication interface within the predetermined period, and the communication interface is acquired within the predetermined period. It is acquired by calculating the second time based on the information regarding the transmission of the communication frame performed by.

According to this, the base station uses a value calculated by using the communication frame transmitted by the terminal and received by the base station for the cumulative transmission time (first time) of the terminal, and the cumulative transmission time is a limit value. Judge that you are approaching. If the cumulative transmission time is acquired from the terminal, dedicated communication for that purpose will be generated, the transmission time of the communication channel will be increased, and as a result, the cumulative transmission time will be close to the limit value. .. By calculating by the base station as described above, it is possible to avoid increasing the transmission time, and as a result, it is possible to leave room for the terminal to transmit another communication frame. Further, with respect to the cumulative transmission time (second time) of the base station, it is determined relatively accurately that the cumulative transmission time has approached the limit value by using the value calculated by the transmitting base station itself. Therefore, the base station can appropriately continue data transmission in the communication band in which the transmission time is limited for each communication channel, while leaving room for the terminal to transmit other communication frames on the communication channel.

Further, the control unit further transfers the management information used for communication between the communication interface and the terminal before changing the communication channel to the communication interface and the terminal after changing the communication channel. Controls used for communication.

According to this, since the base station takes over the management information before and after the channel change and uses it, it is not necessary to perform the management information generation process after the channel change, and the time required if the generation process is performed. Is no longer needed. Therefore, the base station can appropriately continue data transmission in a shorter time in the communication band in which the transmission time is limited for each communication channel.

Further, the terminal according to one aspect of the present invention is a terminal that wirelessly communicates with a base station using a communication band in which the time during which a communication frame can be transmitted is limited for each communication channel, and is a communication interface for wireless communication. And a providing unit that calculates the first time, which is the time when the communication interface transmits a communication frame within a predetermined period ending at the present time, and provides the calculated first time to the base station by the communication interface. , A notification transmitted from the base station based on the first time provided by the providing unit, indicating that the communication channel of wireless communication with the base station is changed is received by the communication interface. In this case, it includes a control unit that changes the communication channel of the communication interface to the communication channel included in the received notification.

According to this, the terminal transmits the cumulative transmission time calculated by the terminal itself that transmitted the frame to the base station, and the base station makes a determination for channel change. Therefore, the base station can relatively accurately determine that the cumulative transmission time has approached the limit value by using the value calculated by the transmitting terminal itself for the cumulative transmission time (first time) of the terminal. it can. Therefore, the terminal can appropriately continue data transmission in the communication band in which the transmission time is limited for each communication channel.

In addition, the communication system according to one aspect of the present invention includes the above base station and the above terminal that wirelessly communicates with the base station.

According to this, the same effect as that of the above base station is obtained.

Further, the communication method according to one aspect of the present invention is a communication method of a base station that wirelessly communicates with a terminal using a communication band in which a communication frame can be transmitted for a limited time for each communication channel. The first time, which is the cumulative time for the terminal to transmit the communication frame by wireless communication within the predetermined period as the final period, and the second, which is the cumulative time for the communication interface of the base station to transmit the communication frame within the predetermined period. When it is determined that at least one of the acquisition step for acquiring the time and the first time and the second time acquired in the acquisition step exceeds a predetermined threshold, the communication channel of the communication interface is changed. It includes a notification step of transmitting the indicated notification to the terminal by the communication interface, and a control step of changing the communication channel of the communication interface when the notification is transmitted in the notification step.

According to this, the same effect as that of the above base station is obtained.

Further, the communication method according to one aspect of the present invention is a communication method of a terminal that wirelessly communicates with a base station using a communication band in which a communication frame can be transmitted for a limited time for each communication channel. The provision step of calculating the first time, which is the time when the communication interface of the terminal transmits a communication frame within a predetermined period to be the final stage, and providing the calculated first time to the base station by the communication interface, and the above-mentioned When the notification transmitted from the base station based on the first time provided in the provision step and the notification indicating that the communication channel of the wireless communication with the base station is changed is received by the communication interface. , A control step of changing the communication channel of the communication interface to the communication channel included in the received notification.

According to this, the same effect as that of the above terminal is obtained.

Further, the program according to one aspect of the present invention is a program for causing a computer to execute the above communication method.

According to this, the same effect as that of the above base station is obtained.

Further, the program according to one aspect of the present invention is a program for causing a computer to execute the above communication method.

According to this, the same effect as that of the above terminal is obtained.

It should be noted that the present invention can be realized not only as a device, but also as a method in which the processing means constituting the device is used as a step, as a program for causing a computer to execute those steps, or as a computer reading in which the program is recorded. It can also be realized as a possible recording medium such as a CD-ROM, or as information, data or a signal indicating the program. Then, those programs, information, data and signals may be distributed via a communication network such as the Internet.

According to the present invention, the base station can appropriately continue data transmission in a communication band in which the transmission time is limited for each communication channel.

FIG. 1 is an explanatory diagram showing a configuration of a base station and a terminal according to an embodiment. FIG. 2 is an explanatory diagram of an example of a table for recording a transmission time. FIG. 3 is an explanatory diagram showing a configuration of a communication frame used for transmission of the cumulative transmission time according to the embodiment. FIG. 4 is a flow chart showing processing of the base station according to the embodiment. FIG. 5 is a flow chart showing a process of providing a transmission time of the terminal according to the embodiment. FIG. 6 is a flow chart showing a process of changing the communication channel of the terminal according to the embodiment. FIG. 7 is a sequence diagram showing processing of the communication system according to the embodiment. FIG. 8 is an explanatory diagram showing a configuration of a base station and a terminal according to a modified example of the embodiment. FIG. 9 is a sequence diagram showing processing of the communication system according to the modified example of the embodiment.

Hereinafter, embodiments will be specifically described with reference to the drawings.

Each of the embodiments described below shows a preferred specific example of the present invention. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. Further, among the constituent elements in the following embodiments, the constituent elements not described in the independent claims indicating the highest level concept of the present invention will be described as arbitrary constituent elements constituting the more preferable embodiment. The same components may be designated by the same reference numerals and description thereof may be omitted.

(Embodiment)
In the present embodiment, a base station and the like capable of appropriately continuing data transmission in a communication band in which the transmission time is limited for each communication channel will be described.

FIG. 1 is an explanatory diagram showing a configuration of a communication system 1 according to the present embodiment.

As shown in FIG. 1, the communication system 1 includes a base station A1 and a terminal S1.

The base station A1 is a base station for wireless communication. The base station A1 is a base station device that bidirectionally relays communication between the terminal S1 and another network (not shown). The base station A1 can wirelessly communicate with the terminal S1 and can also communicate with other networks by wire or wirelessly. Other networks may include local area networks such as offices or factories, the Internet, and the like.

The terminal S1 is a communication terminal that connects to the base station A1 by wireless communication. The terminal S1 can communicate with another network or communicate with the base station A1 by using the relay by the base station A1.

Although only the terminal S1 is shown as a terminal connected to the base station A1, the same description holds true even when a plurality of terminals exist.

Wireless communication between the base station A1 and the terminal S1 is performed in a communication band, for example, a 920 MHz band, in which the time during which a communication frame can be transmitted is limited for each communication channel (also simply referred to as a channel). More specifically, the wireless communication between the base station A1 and the terminal S1 is communication conforming to the IEEE802.11ah standard, and this case will be described as an example, but in addition to this, it conforms to the IEEE802.154g standard. It can also be applied to such communications. The time limit for transmitting a communication frame as described above is based on, for example, a regulation aimed at fair use of radio waves by a plurality of uses or a plurality of communication devices (for example, a regulation of the Radio Law). ..

Specifically, communication in the 920 MHz band is limited to the time limit (specifically, 360 seconds) or less that one communication device transmits per hour on one communication channel. In other words, if one communication device transmits one communication channel for 360 seconds in the last one hour period in the past, the communication device cannot transmit a communication frame within the period. In this case, the communication device can transmit a communication frame on a communication channel different from the communication channel transmitted for 360 seconds in the most recent hour in the past. Here, the "last hour in the past" means the time of one hour from the present time to the past, and may be simply "the most recent hour".

Hereinafter, the configuration of the base station A1 and the terminal S1 will be described in detail.

As shown in FIG. 1, the base station A1 includes a radio IF (interface) 11, an acquisition unit 12, a notification unit 13, and a control unit 14. The acquisition unit 12, the notification unit 13, and the control unit 14 can be realized by the processor executing a predetermined program using the memory.

The wireless IF 11 is a communication interface for wireless communication with the terminal S1. The communication standard of the wireless IF11 is, for example, the IEEE802.11ah standard. The time for the wireless IF 11 to transmit a communication frame has the above limitation. The control unit 14 controls the wireless IF 11 to prohibit the transmission of the amount of communication frames exceeding the limit value.

The wireless IF 11 is an interface for wireless communication. The wireless IF 11 includes an antenna, a transmission / reception circuit for wireless communication signals, and the like.

The wireless IF 11 communicates with the terminal S1 to establish wireless communication. More specifically, the wireless IF11 establishes wireless communication by performing communication for authentication (Authentication), communication for connection establishment (Association), communication of 4-way handshake, and the like. Generates information necessary for wireless communication such as generation of encryption key. Further, the wireless IF 11 changes the communication channel under the control of the control unit 14.

The acquisition unit 12 is a processing unit that acquires the cumulative transmission time of the terminal S1 and the base station A1. The acquisition unit 12 has the first time, which is the time when the terminal S1 transmits the communication frame by wireless communication within the predetermined period ending at the present time, and the time when the own unit (wireless IF11) transmits the communication frame within the predetermined period. To get the second time and.

Here, the time length of the predetermined period is a time that is a unit of communication restriction, and is one hour in the case of communication restriction of 360 seconds or less per hour in the 920 MHz band. That is, the predetermined period is the most recent hour from the present time to the past. The start of the predetermined period is one hour before the present time.

The first time is a cumulative transmission time which is a cumulative value of the time when the terminal S1 transmits a communication frame on a predetermined channel within a predetermined period. The acquisition unit 12 acquires the first time by receiving, for example, a communication frame including the first time calculated by the terminal S1.

The second time is a cumulative transmission time which is a cumulative value of the time when the base station A1 transmits a communication frame on a predetermined channel within a predetermined period. The acquisition unit 12 acquires by calculating the second time based on the information about the communication frame transmitted by the radio IF 11 within the predetermined period. In order to calculate the second time, as an example, a table (described later) for recording the transmission time for each time interval included in the predetermined period is used.

The acquisition unit 12 stores the acquired cumulative transmission time of the terminal S1 and the base station A1 in a memory or the like in association with the communication channel. In this way, the acquisition unit 12 manages the cumulative transmission time of the terminal S1 and the base station A1 for each communication channel that can be used by the base station A1 and the terminal S1 in the communication system 1. For example, in 24ch, the cumulative transmission time of the terminal S1 is managed in association with 45 msec.

Further, when a plurality of terminals are connected under the base station A1, the acquisition unit 12 acquires the cumulative transmission time for each terminal, associates it with the communication channel, and stores it in a memory or the like. In this way, the acquisition unit 12 can manage the cumulative transmission time corresponding to each of the plurality of terminals that perform wireless communication under the control of the own device (base station A1). For example, in 24ch, the cumulative transmission time of the terminal S1 is 45 msec, the cumulative transmission time of the terminal S2 (not shown) is 90 msec, and the cumulative transmission time of the terminal S3 (not shown) is 180 msec. to manage.

The notification unit 13 is a processing unit that transmits a channel change notification to the terminal S1. The notification unit 13 is a channel change notification indicating that the communication channel of wireless communication is changed when it is determined that at least one of the first time and the second time acquired by the acquisition unit 12 exceeds a predetermined threshold value. Is transmitted to the terminal S1 by the wireless IF11. Here, the predetermined threshold value can be set to 9.5% of the total time, for example, in the case of communication in the 920 MHz band. This corresponds to 342 seconds per hour.

In addition, the notification unit 13 determines the communication channel to be changed, which should be included in the channel change notification. As the communication channel to be changed, a communication channel having a smaller amount of communication in the most recent hour may be determined with higher priority. The communication channel with the smaller amount of communication in the most recent hour can be determined with reference to the above table (above) for recording the transmission time for each time interval included in the predetermined period. Further, the communication channel to be changed may be determined in a predetermined order by the user among the communicable channels, or may be set at the time of shipment from the factory.

It is desirable to determine the communication channel in which the communication volume in the latest hour does not exceed the limit value, but the channel in which the communication volume in the latest hour exceeds the limit value may be determined. In that case, communication by the wireless IF 11 becomes possible after waiting until the communication amount for the most recent hour does not exceed the limit value due to the passage of time.

The channel change notification may be a communication frame including at least the change destination channel. For the channel change notification, for example, a CSA (Channel Switch Announcement) frame conforming to the IEEE802.11h standard can be used.

The control unit 14 is a processing unit that controls to change the communication channel of the wireless IF 11 when the notification unit 13 transmits a channel change notification. The control unit 14 changes the communication channel of the wireless IF 11 to the communication channel of the change destination determined by the notification unit 13. After that, the wireless IF 11 establishes wireless communication with the wireless IF 21 of the terminal S1 on the changed communication channel, and the terminal S1 and the base station A1 communicate with each other.

When the communication channel is changed, the control unit 14 further changes the communication channel from the management information used for communication between the wireless IF 11 and the terminal S1 before changing the communication channel. Controls used for communication between the wireless IF 11 and the terminal S1 may be used. Here, the management information is information necessary for wireless communication connection, and is information related to authentication or encryption. In this way, the management information before changing the communication channel can be used in the communication after changing the communication channel, and the processing required if new management information is to be generated (for example, in wireless communication). There is an advantage that communication for establishment can be omitted.

Further, as shown in FIG. 1, the terminal S1 includes a wireless IF 21, a providing unit 22, and a control unit 23. The providing unit 22 and the control unit 23 can be realized by the processor executing a predetermined program using the memory.

The wireless IF 21 is an interface for wireless communication. The wireless IF 21 includes an antenna, a transmission / reception circuit for wireless communication signals, and the like.

The wireless IF 21 communicates with the base station A1 to establish wireless communication. More specifically, the wireless IF21 establishes wireless communication by performing communication for authentication, communication for establishing a connection, communication for 4-way handshake, etc., and for wireless communication such as generation of an encryption key. Generate the required information. Further, the wireless IF 21 changes the communication channel under the control of the control unit 23.

The providing unit 22 is a processing unit that provides the cumulative transmission time of the terminal S1 to the base station A1. The providing unit 22 calculates the first time, which is the time when the wireless IF 21 transmits the communication frame within a predetermined period ending at the present time, and provides the calculated first time to the base station A1 by the wireless IF 21. Here, the time length of the predetermined period is, for example, one hour for communication in the 920 MHz band as described above (see the description of the acquisition unit 12 of the base station A1).

The control unit 23 is a processing unit that controls the communication channel of the wireless IF 21. The control unit 23 is a notification transmitted from the base station A1 based on the first time provided by the providing unit 22, and is a notification indicating that the communication channel for wireless communication with the base station A1 is changed (change destination). When the wireless IF21 (including the communication channel) is received, the communication channel of the wireless IF21 is changed to the communication channel included in the received notification. After that, the wireless IF 21 establishes wireless communication with the wireless IF 11 of the base station A1 on the changed communication channel, and the terminal S1 and the base station A1 communicate with each other.

The control unit 23, like the control unit 14 of the base station A1, was used for communication between the wireless IF 11 and the terminal S1 when the communication channel was changed and before the communication channel was changed. The management information may be controlled to be used for communication between the wireless IF 11 and the terminal S1 after the communication channel is changed.

FIG. 2 is an explanatory diagram of a table 40 which is an example of a table for recording a transmission time. The table 40 is used, for example, by the acquisition unit 12 of the base station A1 to acquire the transmission time of the radio IF 11. The table 40 is an example of information for recording the transmission time, and information in another format may be used.

Table 40 divides one hour, that is, 3600 seconds into a time interval (also simply referred to as an interval) every 100 milliseconds, and records the transmission time of the radio IF 11 in each interval. There are 36000 sections. One entry in table 40 corresponds to one interval.

In table 40, each entry has a number 41 and a transmission time 42.

The number 41 is a serial number of each entry.

The transmission time 42 is the transmission time of the radio IF 11 in the section corresponding to each entry. The transmission time 42 is, for example, a transmission time expressed in milliseconds. It is zero if there is no transmission in the section corresponding to the entry, and 100 if the communication frame is transmitted at all times in the section corresponding to the entry.

As an example, it is shown that the radio IF11 did not transmit in the section corresponding to the entry with the number 1 in FIG. 2, and the radio IF11 was for 45 milliseconds in the section corresponding to the entry with the number 2. It is shown that the transmission was made.

The acquisition unit 12 monitors the transmission of the wireless IF 11 and acquires the transmission time of the wireless IF 11 for 100 milliseconds for each section of 100 milliseconds. Here, the transmission time also includes the time related to the retransmission of the communication frame.

Then, the acquisition unit 12 records the acquired transmission time in the transmission time 42 of the entry of the number corresponding to the section while increasing the number by 1 for each section. The transmission time is recorded in the entry with the number 36000 Next, the transmission time is recorded in the entry with the number 1. In this way, the transmission time in each section is cyclically recorded in the table 40. As a result, since the transmission time in each section for the latest one hour is always recorded in the table 40, the cumulative transmission time of the latest one hour can be obtained at any time by calculating the total of the transmission times 42. ..

The above-mentioned cumulative transmission time calculation method can also be used when the terminal S1 calculates the cumulative transmission time of the wireless IF 21. The transmission time 42 is the transmission time of the radio IF 21 in the section corresponding to each entry.

FIG. 3 is an explanatory diagram showing a configuration of a communication frame 50 used for transmission of the cumulative transmission time according to the present embodiment. The communication frame 50 shown in FIG. 3 can be used when the terminal S1 transmits the cumulative transmission time of the terminal S1 to the base station A1. The communication frame 50 is, for example, a communication frame having an action frame frame format in the IEEE802.11 series standard.

As shown in FIG. 3, the communication frame 50 includes a DA (Destination Address), an SA (Source Address), and an action field.

The DA is the destination address of the communication frame 50, and includes the MAC (Media Access Control) address of the base station A1.

The SA is the source address of the communication frame 50, and includes the MAC address of the terminal S1.

The action field is a field provided for additional functions in the IEEE 802.11 series standard. Action fields include categories, vendor IDs and vendor-specific information. For example, the category field is set to 126 or 127, which means vendor-specific information. In the field of vendor-specific information, the MAC address of the terminal S1, which is an identifier of the communication device related to the cumulative transmission time, is set as the device ID. In the cumulative transmission time, the cumulative transmission time of the terminal S1 expressed in milliseconds is set.

The processing of the base station A1 and the terminal S1 configured as described above will be described below.

FIG. 4 is a flow chart showing processing of the base station A1 according to the present embodiment.

In step S101, the acquisition unit 12 acquires the cumulative transmission time of the terminal S1. The acquisition of the cumulative transmission time of the terminal S1 is performed by receiving the cumulative transmission time of the terminal S1 calculated by the terminal S1. Further, the acquisition unit 12 stores the acquired terminal S1 together with the cumulative transmission time in a memory (not shown) or the like in association with the communication channel extracted from the communication frame 50.

In step S102, the acquisition unit 12 acquires the cumulative transmission time of the base station A1. The acquisition of the cumulative transmission time of the base station A1 is performed, for example, by a method using the table 40, more specifically, by calculating the total of the transmission times 42 recorded in the table 40. Further, the acquisition unit 12 associates the acquired cumulative transmission time of the base station A1 with the communication channel and stores it in a memory (not shown) or the like.

In step S103, the notification unit 13 determines whether or not either the cumulative transmission time of the terminal S1 acquired in step S101 or the cumulative transmission time of the base station A1 acquired in step S102 exceeds a predetermined threshold value. .. If it is determined that any of the cumulative transmission times exceeds a predetermined threshold value (Yes in step S103), the process proceeds to step S104, and if not (No in step S103), step S101 is executed again.

In step S104, the notification unit 13 determines the channel to be changed.

In step S105, the notification unit 13 transmits a channel change notification including the channel determined in step S104 to the terminal S1.

In step S106, the control unit 14 changes the communication channel of the wireless IF 11. After that, the wireless IF 11 makes a wireless communication connection with the wireless IF 21 of the terminal S1 on the changed communication channel, and communication becomes possible.

In parallel with the above processing, the base station A1 performs a transmission restriction process for observing the regulation of the communication band. Specifically, the base station A1 determines whether or not the transmission time does not exceed the limit value when the communication frame to be transmitted is transmitted before transmitting each of the communication frames to be transmitted. If the limit value is exceeded when the communication frame is transmitted, the process of canceling the transmission of the communication frame is performed. Also in this transmission restriction process, the transmission time within a predetermined period of the wireless IF 11 is used. Therefore, when acquiring the cumulative transmission time in step S102, the cumulative transmission time may be obtained from the table used in the transmission restriction process.

FIG. 5 is a flow chart showing a process of providing a transmission time of the terminal S1 according to the present embodiment.

In step S201, the providing unit 22 calculates the cumulative transmission time of the wireless IF 21. The cumulative transmission time can be calculated by calculating the total of the transmission times 42 for one hour included in the table 40. The process of step S201 is executed, for example, every 1 minute to 5 minutes, and more specifically, every 1 minute.

In step S202, the providing unit 22 provides the cumulative transmission time of the radio IF 21 calculated in step S201 to the base station A1 by the radio IF 21. After finishing step S202, step S201 is executed.

In parallel with the above processing, the terminal S1 performs a transmission restriction processing for observing the regulation of the communication band. The transmission restriction process is the same process as that performed by the base station A1. Therefore, when acquiring the cumulative transmission time in step S201, the cumulative transmission time may be obtained from the table used in the transmission restriction process.

FIG. 6 is a flow chart showing a process of changing the communication channel of the terminal S1 according to the present embodiment. The process shown in FIG. 6 can be performed in parallel with the process shown in FIG.

In step S211 the control unit 23 determines whether or not the channel change notification has been received from the base station A1 by the wireless IF 21. If it is determined that the channel change notification has been received (Yes in step S211), step S212 is executed, and if not (No in step S211), step S211 is executed again. That is, the control unit 23 waits in step S211 until it receives the channel change notification.

In step S212, the control unit 23 changes the communication channel of the wireless IF 21 to the communication channel included in the channel change notification received in step S211.

FIG. 7 is a sequence diagram showing the processing of the communication system 1 according to the present embodiment. In FIG. 7, in a state where the base station A1 and the terminal S1 are communicating, the base station A1 and the terminal S1 change the communication channel based on the cumulative transmission time of the terminal S1 exceeding a predetermined threshold value. A series of flow until the communication is continued is shown.

First, processing for connecting wireless communication is performed between the base station A1 and the terminal S1. The process for connection includes a process for authentication, a process for establishing a connection, and a 4-way handshake communication. When the communication for connection is completed, the base station A1 and the terminal S1 are in a communicable state.

After that, the terminal S1 transmits the cumulative transmission time to the base station A1 every minute (step S202), and the base station A1 receives the transmitted cumulative transmission time (step S101). The cumulative transmission times to be transmitted are shown as cumulative transmission times T11, T12, ..., T1N in FIG. Further, the base station A1 is acquired by calculating the cumulative transmission times T21, T22, ..., T2N of the base station A1 every minute (step S102).

When the base station A1 acquires the cumulative transmission times T11 and the like and T21 and the like, it determines whether or not the acquired cumulative transmission time exceeds a predetermined threshold value th (step S103). Here, it is assumed that the cumulative transmission times T11, T12, ... Do not exceed the threshold value th, and the cumulative transmission time T1N exceeds the threshold value th.

Then, the base station A1 determines that the cumulative transmission time T1N exceeds the threshold value th (Yes in step S103), determines the channel to be changed (step S104), and transmits the channel change notification to the terminal S1 (step S105). ), The communication channel is changed (step S106). The terminal S1 that has received the channel change notification also changes the communication channel according to the channel change notification (step S212).

After that, the base station A1 and the terminal S1 are in a state of being able to communicate with each other on the changed communication channel. At this time, since the information such as the encryption key generated at the time of the initial communication can be continuously used, it is not necessary to perform a new process for connection. Therefore, there is an advantage that communication is possible without newly requiring time for connection.

(Modified example of the embodiment)
In this modification, a technique for calculating the cumulative transmission time of a terminal in a base station or the like that can appropriately continue data transmission in a communication band in which the transmission time is limited for each communication channel will be described.

FIG. 8 is an explanatory diagram showing a configuration of a communication system 2 including a base station A2 and a terminal S2 according to a modified example of the present embodiment.

As shown in FIG. 8, the base station A2 according to this modification includes a radio IF 11, an acquisition unit 12A, a notification unit 13, and a control unit 14. Further, the terminal S2 according to this modification includes a wireless IF 21 and a control unit 23.

Here, the base station A2 is different from the base station A1 of the embodiment in that the acquisition unit 12A is provided. Further, the terminal S2 is different from the terminal S1 of the embodiment in that the providing unit 22 is not provided.

Hereinafter, the acquisition unit 12A will be mainly described.

The acquisition unit 12A acquires the cumulative transmission time of the terminal S2, that is, the first time, based on the information (time required for reception, etc.) regarding the reception of the communication frame transmitted by the terminal S2 by the wireless IF 11 within a predetermined period. Do. Specifically, the acquisition unit 12A calculates the cumulative transmission time of the most recent 1 hour of the terminal S2 by the method using the table 40 shown in FIG. 2 for the communication frame received by the wireless IF 11 from the terminal S2.

FIG. 9 is a sequence diagram showing the processing of the communication system 2 according to this modification.

FIG. 9 is a sequence diagram showing the processing of the communication system 2 according to the present embodiment. In FIG. 9, in a state where the base station A2 and the terminal S2 are communicating, the base station A2 and the terminal S2 change the communication channel based on the cumulative transmission time of the terminal S2 exceeding a predetermined threshold value. A series of flow until the communication is continued is shown. FIG. 9 is a sequence diagram corresponding to FIG. 7 of the embodiment.

First, processing for connecting wireless communication is performed between the base station A2 and the terminal S2. This process is the same as the process of the base station A1 and the terminal S1 in the embodiment.

After that, the base station A2 acquires by calculating the cumulative transmission times T11, T12, ..., T1N, and T21, T22, ..., T2N. At this time, the base station A2 does not need to receive information indicating the cumulative transmission time of the terminal S2 from the terminal S2 in calculating T21, T22, ..., T2N. That is, the base station A2 can calculate the cumulative transmission time of the most recent 1 hour of the terminal S2 in the acquisition unit 12A.

The base station A2 determines whether or not the acquired cumulative transmission time exceeds the threshold value th (step S103). Here, it is assumed that the cumulative transmission times T11, T12, ... Do not exceed the threshold value th, and the cumulative transmission time T1N exceeds the threshold value th.

Then, the base station A2 determines the channel to be changed (step S104), transmits the channel change notification to the terminal S2 (step S105), and changes the communication channel (step S106). The terminal S2 that has received the channel change notification also changes the communication channel according to the channel change notification (step S212).

After that, the base station A2 and the terminal S2 are in a state of being able to communicate with each other on the changed communication channel. At this time, since the information such as the management information generated at the time of the initial communication can be continuously used, the base station A2 and the terminal S2 do not need to perform the processing for a new connection. Therefore, the base station A2 and the terminal S2 have an advantage that they can communicate with each other without requiring time for a new connection.

Further, there is an advantage that it is not necessary to transmit the cumulative transmission time from the terminal S2 to the base station A2. When transmitting the cumulative transmission time described above, the terminal S2 will generate a dedicated communication for that purpose from the terminal S2 to the base station A2, which will increase the transmission time of the terminal S2 on the communication channel. Therefore, if the cumulative transmission time is not transmitted from the terminal S2 to the base station A2, it is possible to avoid increasing the transmission time and leave room for the terminal S2 to transmit another communication frame.

As described above, in the base station according to the embodiment and the modified example, when the cumulative transmission time of at least one of the terminal and the base station approaches the limit value for each communication channel, both the terminal and the base station communicate with each other. Change the channel. At this time, since the notification for notifying the channel change is transmitted to the terminal, the terminal can change the communication channel more reliably. Further, since the terminal can know the communication channel of the change destination by the notification, the communication can be started on the communication channel of the change destination without requiring the terminal to scan the communication channel to search for the base station. In this way, the base station can appropriately continue data transmission in the communication band in which the transmission time is limited for each communication channel.

In addition, the base station can relatively accurately determine that the cumulative transmission time has approached the limit value by using the value calculated by the transmitting terminal itself for the cumulative transmission time (first time) of the terminal. it can. Further, regarding the cumulative transmission time (second time) of the base station, it is possible to relatively accurately determine that the cumulative transmission time has approached the limit value by using the value calculated by the transmitting base station itself. Therefore, the base station can appropriately continue data transmission by making a determination based on a more accurate cumulative transmission time in a communication band in which the transmission time is limited for each communication channel.

Further, the base station uses a value calculated by using the communication frame transmitted by the terminal and received by the base station for the cumulative transmission time (first time) of the terminal, and the cumulative transmission time approaches the limit value. Judge that. If the cumulative transmission time is acquired from the terminal, dedicated communication for that purpose will be generated, the transmission time of the communication channel will be increased, and as a result, the cumulative transmission time will be close to the limit value. .. By calculating by the base station as described above, it is possible to avoid increasing the transmission time, and as a result, it is possible to leave room for the terminal to transmit another communication frame. Further, with respect to the cumulative transmission time (second time) of the base station, it is determined relatively accurately that the cumulative transmission time has approached the limit value by using the value calculated by the transmitting base station itself. Therefore, the base station can appropriately continue data transmission in the communication band in which the transmission time is limited for each communication channel, while leaving room for the terminal to transmit other communication frames on the communication channel.

In addition, since the base station takes over the management information before and after the channel change and uses it, it is not necessary to perform the management information generation process after the channel change, and if the generation process is performed, the time required is unnecessary. Become. Therefore, the base station can appropriately continue data transmission in a shorter time in the communication band in which the transmission time is limited for each communication channel.

Further, the terminal according to the embodiment transmits the cumulative transmission time calculated by the terminal itself that transmitted the frame to the base station, and the base station makes a determination for channel change. Therefore, the base station can relatively accurately determine that the cumulative transmission time has approached the limit value by using the value calculated by the transmitting terminal itself for the cumulative transmission time (first time) of the terminal. it can. Therefore, the terminal can appropriately continue data transmission in the communication band in which the transmission time is limited for each communication channel.

It should be noted that the present invention can be realized not only as a device, but also as a method in which the processing means constituting the device is used as a step, as a program for causing a computer to execute those steps, or as a computer reading in which the program is recorded. It can also be realized as a possible recording medium such as a CD-ROM, or as information, data or a signal indicating the program. Then, those programs, information, data and signals may be distributed via a communication network such as the Internet.

Although the base station, the terminal, and the like of the present invention have been described above based on the embodiments, the present invention is not limited to the embodiments. As long as the gist of the present invention is not deviated, various modifications that can be conceived by those skilled in the art are applied to the present embodiment, and a form constructed by combining components in different embodiments is also included in the scope of the present invention. ..

The present invention can be used for base stations (access points, etc.) and terminals (personal computers, smartphones, etc.) that perform wireless communication in a communication band with a limited transmission amount.

1, 2 Communication system 11, 21 Wireless IF
12, 12A Acquisition unit 13 Notification unit 14, 23 Control unit 22 Providing unit 40 Table 41 Number 42 Transmission time 50 Communication frame A1, A2 Base station S1, S2 Terminal

Claims (10)

A base station that wirelessly communicates with a terminal using a communication band in which the time that can transmit a communication frame is limited for each communication channel.
A communication interface for wireless communication and
The first time, which is the cumulative time for the terminal to transmit a communication frame by wireless communication within a predetermined period ending at the present time, and the second time, which is the cumulative time for the communication interface to transmit a communication frame within the predetermined period. And the acquisition department to acquire,
When it is determined that at least one of the first time and the second time acquired by the acquisition unit exceeds a predetermined threshold value, the terminal is notified by the communication interface that the communication channel of the communication interface is changed. Notification section to send to
A base station including a control unit that changes the communication channel of the communication interface when the notification unit transmits the notification. The acquisition unit
By receiving the communication frame including the first time calculated by the terminal, the first time is acquired.
The base station according to claim 1, which is acquired by calculating the second time based on the information regarding the transmission of the communication frame performed by the communication interface within the predetermined period. The acquisition unit
Obtained by calculating the first time based on the information regarding the reception of the communication frame transmitted by the terminal within the predetermined period by the communication interface.
The base station according to claim 1, which is acquired by calculating the second time based on the information regarding the transmission of the communication frame performed by the communication interface within the predetermined period. The control unit further
Claim to control the management information used for communication between the communication interface and the terminal before changing the communication channel to be used for communication between the communication interface and the terminal after changing the communication channel. The base station according to any one of 1 to 3. A terminal that wirelessly communicates with a base station using a communication band in which the time during which a communication frame can be transmitted is limited for each communication channel.
A communication interface for wireless communication and
A providing unit that calculates the first time, which is the time when the communication interface transmits a communication frame within a predetermined period ending at the present time, and provides the calculated first time to the base station by the communication interface.
When a notification transmitted from the base station based on the first time provided by the providing unit and indicating that the communication channel for wireless communication with the base station is changed is received by the communication interface. A terminal including a control unit that changes the communication channel of the communication interface to the communication channel included in the received notification. The base station according to any one of claims 1 to 4 and
A communication system including the terminal according to claim 5, which wirelessly communicates with the base station. It is a communication method of a base station that wirelessly communicates with a terminal using a communication band in which the time during which a communication frame can be transmitted is limited for each communication channel.
The first time, which is the cumulative time for the terminal to transmit a communication frame by wireless communication within a predetermined period ending at the present time, and the cumulative time for the communication interface of the base station to transmit a communication frame within the predetermined period. The acquisition step to get the second time and
When it is determined that at least one of the first time and the second time acquired in the acquisition step exceeds a predetermined threshold value, the terminal is notified by the communication interface indicating that the communication channel of the communication interface is changed. Notification steps to send to
A communication method including a control step for changing a communication channel of the communication interface when the notification is transmitted in the notification step. It is a communication method of a terminal that wirelessly communicates with a base station using a communication band in which the time during which a communication frame can be transmitted is limited for each communication channel.
A provision step of calculating the first time, which is the time when the communication interface of the terminal transmits a communication frame within a predetermined period ending at the present time, and providing the calculated first time to the base station by the communication interface. ,
When the notification transmitted from the base station based on the first time provided in the provision step and the notification indicating that the communication channel of the wireless communication with the base station is changed is received by the communication interface. A communication method including a control step of changing the communication channel of the communication interface to the communication channel included in the received notification. A program for causing a computer to execute the communication method according to claim 7. A program for causing a computer to execute the communication method according to claim 8.

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