JP2014236357A - Communication control method, communication control program, and communication control device - Google Patents

Abstract

An object of the present invention is to improve throughput. A communication control device 120 controls communication in a communication system 100 in which an access point 110 and a terminal 101 are connected to be communicable with each other. The communication control device 120 includes an acquisition unit 121 and a control unit 122. The acquisition unit 121 acquires the transmission rate from the access point 110 to the terminal 101 once or a plurality of times within a predetermined period. The control unit 122 disconnects the communication between the access point 110 and the terminal 101 according to the value calculated based on the transmission rate acquired by the acquisition unit 121. [Selection] Figure 1

Description

  The present invention relates to a communication control method, a communication control program, and a communication control apparatus.

  Conventionally, in a configuration in which broadcast information is transmitted from a master unit to a slave unit, a technology is known in which a slave unit with a poor response is disconnected from the broadcast transmission target and is retransmitted when the line quality of the disconnected slave unit becomes good. (For example, see Patent Document 1 below.) In addition, a technique for determining call disconnection based on communication quality based on RSSI (Received Signal Strength Indicator) is known (for example, see Patent Document 2 below).

  In recent years, the number of devices compatible with WLAN (Wireless Local Area Network) such as WiFi (Wireless Fidelity) is increasing. WiFi is a registered trademark. As the number of devices compatible with WLAN increases, radio interference and congestion increase, and there is an area where stable throughput cannot be obtained despite a strong electric field. In addition, transmission from the access point to the terminal arrives without any problem, but transmission from the terminal to the access point is difficult to reach, and there is a fringe area where stable throughput cannot be obtained.

JP-A-2-90831 JP 2000-174694 A

  However, in the conventional WLAN, the influence of radio wave interference and congestion cannot be grasped, and the connection between the access point and the terminal is maintained as much as possible. Therefore, it is difficult to eliminate the decrease in throughput.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a communication control method, a communication control program, and a communication control apparatus capable of improving throughput in order to solve the above-described problems caused by the prior art.

  In order to solve the above-described problems and achieve the object, according to one aspect of the present invention, when controlling communication in a communication system in which an access point and a terminal are connected to be able to communicate with each other, the access point Communication that acquires the transmission rate from the terminal to the terminal once or a plurality of times within a predetermined period, and disconnects communication between the access point and the terminal according to a value calculated based on the acquired transmission rate A control method, a communication control program, and a communication control device are proposed.

  According to another aspect of the present invention, in a communication control apparatus that performs connection control related to the wireless terminal in response to a connection request including reception strength from the wireless terminal, a transmission rate related to the wireless terminal satisfies a predetermined reference. When the communication connection is disconnected, the communication connection related to the wireless terminal is disconnected, the reception strength when the communication connection is disconnected is stored, and a new connection request transmitted from the wireless terminal after the communication connection is disconnected is stored. When it is detected that the reception intensity exceeding the received intensity is not indicated, a communication control method, a communication control program, and a communication control apparatus that do not permit connection for the new connection request are proposed.

  According to one aspect of the present invention, it is possible to improve the throughput.

FIG. 1 is a diagram illustrating an example of a communication system according to the first embodiment. FIG. 2 is a diagram of an example of an access point according to the second embodiment. FIG. 3 is a diagram illustrating an example of a hardware configuration of the access point. FIG. 4 is a diagram illustrating an example of the quality monitoring black list. FIG. 5 is a diagram illustrating an example of a message used for disconnecting a terminal. FIG. 6 is a flowchart illustrating an example of processing performed by the transmission failure rate monitoring unit. FIG. 7 is a flowchart illustrating an example of processing performed by the transmission rate management unit. FIG. 8 is a flowchart illustrating an example of processing by the average transmission rate monitoring control unit. FIG. 9 is a flowchart illustrating an example of processing by the connection frame reception availability control unit. FIG. 10 is a flowchart illustrating an example of processing performed by the blacklist management unit. FIG. 11 is a sequence diagram illustrating an example of disconnection of a connected terminal. FIG. 12 is a diagram illustrating an example of regular monitoring of the average transmission rate. FIG. 13 is a sequence diagram illustrating an operation example 1 of connection frame reception availability control. FIG. 14 is a sequence diagram illustrating an operation example 2 of connection frame reception availability control. FIG. 15 is a sequence diagram illustrating operation example 3 of connection frame reception availability control. FIG. 16 is a sequence diagram illustrating an operation example 4 of connection frame reception availability control. FIG. 17 is a sequence diagram illustrating an operation example 5 of connection frame reception availability control. FIG. 18 is a sequence diagram illustrating an operation example 6 of connection frame reception availability control.

  Exemplary embodiments of a communication control method, a communication control program, and a communication control device according to the present invention will be described below in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram illustrating an example of a communication system according to the first embodiment. As illustrated in FIG. 1, the communication system 100 according to the first embodiment includes an access point 110, a communication control device 120, and a terminal 101. In the communication system 100, an access point 110 and a terminal 101 are connected so that they can communicate with each other.

  The access point 110 is an access point such as a Hotspot gateway. The terminal 101 is a wireless terminal that performs wireless communication with the access point 110. A plurality of terminals 101 may exist. The communication system 100 can be applied to, for example, a WLAN.

  The communication control device 120 controls communication in the communication system 100. The communication control device 120 may be a device provided in the access point 110, or may be another device that can communicate with the access point 110. The communication control device 120 includes an acquisition unit 121 and a control unit 122.

  The acquisition unit 121 acquires the transmission rate from the access point 110 to the terminal 101 once or a plurality of times within a predetermined period. Then, the acquisition unit 121 notifies the control unit 122 of the acquired transmission rate. The transmission rate from the access point 110 to the terminal 101 is controlled by the access point 110, for example, according to the degree of signal arrival from the access point 110 to the terminal 101. The degree of signal arrival can be, for example, an arrival rate obtained by calculating a ratio of the number of signal arrivals to the number of signal transmissions.

  The control unit 122 disconnects the communication between the access point 110 and the terminal 101 according to the value calculated based on the transmission rate notified from the acquisition unit 121. When the acquisition unit 121 acquires the transmission rate once within a predetermined period, the value calculated based on the transmission rate can be, for example, the transmission rate acquired once. When the transmission rate is acquired by the acquisition unit 121 a plurality of times within a predetermined period, the value calculated based on the transmission rate can be, for example, an average value of the transmission rates acquired a plurality of times.

  For example, the control unit 122 maintains communication between the access point 110 and the terminal 101 when the value calculated based on the transmission rate notified from the acquisition unit 121 is a predetermined value or more. In addition, the control unit 122 disconnects communication between the access point 110 and the terminal 101 when the value calculated based on the transmission rate notified from the acquisition unit 121 is less than a predetermined value.

  When the communication with the access point 110 is disconnected, the terminal 101 connects to a line different from the access point 110, for example. As a line different from the access point 110, for example, a WLAN access point different from the access point 110, cellular such as 3G (3rd Generation: 3rd generation mobile communication system), LTE (Long Term Evolution), LTE-Advanced, etc. List the line.

  Thus, by disconnecting communication between the terminal 101 having a low downlink transmission rate and the access point 110, the terminal 101 having a low throughput can be prompted to switch to another line. For this reason, fringes in the communication system 100 can be reduced, and the throughput of another wireless terminal connected to the access point 110 can be improved. Also, the disconnected terminal 101 can improve throughput by connecting to a line different from the access point 110 having a low downlink transmission rate.

  Further, by disconnecting communication based on the downlink transmission rate controlled by the access point 110, communication between the terminal 101 and the access point 110 having low throughput can be performed without reporting the communication quality from the terminal 101. Can be cut. For this reason, it is possible to improve the throughput without adding a function to the terminal 101.

  Further, by using the downlink transmission rate, it is possible to disconnect the communication according to the actual arrival degree of the signal from the access point 110 to the terminal 101. Thereby, compared with the case where RSSI is used, for example, the actual degree of arrival of the signal from the access point 110 to the terminal 101 can be accurately grasped while suppressing the influence of ambient noise. For this reason, when the actual reach is low, the terminal 101 can be disconnected to improve the throughput.

<Guard processing based on reception strength>
Further, the acquisition unit 121 of the communication control apparatus 120 acquires the reception strength from the terminal 101 at the access point 110 when a request signal for connection to the access point 110 is transmitted from the terminal 101 to the access point 110. Also good. The reception strength from terminal 101 at access point 110 is, for example, the reception strength of a request signal transmitted from terminal 101 to access point 110. The reception strength is, for example, RSSI. The acquisition unit 121 notifies the control unit 122 of the acquired reception intensity.

  The control unit 122 causes the access point 110 to discard the request signal from the terminal 101 in accordance with the reception strength notified from the acquisition unit 121 so that the access point 110 does not respond to the request signal from the terminal 101. Control.

  For example, when the reception strength notified from the acquisition unit 121 is equal to or greater than a predetermined value, the control unit 122 causes the access point 110 to respond to the request signal from the terminal 101 and connects the access point 110 and the terminal 101. To do. In addition, when the reception strength notified from the acquisition unit 121 is less than a predetermined value, the control unit 122 causes the access point 110 to discard the request signal from the terminal 101, and to access the request signal from the terminal 101. 110 is not made to respond. If there is no response from the access point 110 to the request signal, the terminal 101 connects to a line different from the access point 110, for example.

  Thereby, it is possible to prevent the terminal 101 having a low reception intensity at the access point 110 from being connected to the access point 110. Therefore, the terminal 101 that cannot expect a high transmission rate can be prevented from being connected to the access point 110. For this reason, fringes in the communication system 100 can be reduced, and the throughput of another wireless terminal connected to the access point 110 can be improved. Even in the disconnected terminal 101, throughput can be improved by connecting to a line different from the access point 110 having low reception strength.

  Further, by discarding the request signal based on the reception strength measurable at the access point 110, the terminal 101 that cannot expect high throughput is not connected to the access point 110 without reporting the communication quality from the terminal 101. Can be. For this reason, it is possible to improve the throughput without adding a function to the terminal 101.

  Note that discarding the request signal is equivalent to the operation when the request signal does not reach the access point 110 when viewed from the terminal 101, and is not affected by the function of the terminal 101. Further, the same effect can be obtained by performing an operation of returning a rejection response instead of an operation of discarding the request signal.

<Reconnection of disconnected terminal>
In addition, when the communication control device 120 disconnects the communication between the access point 110 and the terminal 101 according to the value calculated based on the transmission rate, the communication from the terminal 101 and the terminal 101 at the access point 110 is performed. Correspondence information for associating reception intensity may be stored. The reception strength stored in the communication control device 120 is, for example, the reception strength from the terminal 101 at the access point 110 immediately before the terminal 101 is disconnected.

  The acquisition unit 121 acquires the reception strength from the terminal 101 at the access point 110 when a request signal for connection to the access point 110 is transmitted from the terminal 101 included in the stored correspondence information to the access point 110. To do. The acquisition unit 121 notifies the control unit 122 of the acquired reception intensity.

  Based on the difference between the reception strength notified from the acquisition unit 121 and the reception strength at the time of disconnection of the terminal 101 associated with the terminal 101 in the stored correspondence information, the control unit 122 sets the access point 110 to The request signal from the terminal 101 is discarded.

  For example, when the reception strength notified from the acquisition unit 121 is equal to or higher than a strength obtained by adding a predetermined amount to the reception strength when the terminal 101 is disconnected, the control unit 122 responds to the request signal from the terminal 101 with an access point. 110 is made to respond. Thereby, the access point 110 and the terminal 101 are connected. In this case, the control unit 122 may delete the correspondence information about the terminal 101.

  In addition, when the reception strength notified from the acquisition unit 121 is less than the strength obtained by adding a predetermined amount to the reception strength at the time of disconnection, the control unit 122 causes the access point 110 to discard the request signal from the terminal 101. In this case, the access point 110 does not respond to the request signal from the terminal 101. If there is no response from the access point 110 to the request signal, the terminal 101 connects to a line different from the access point 110, for example.

  As a result, even if the terminal 101 disconnected from the access point 110 transmits a request signal because the transmission rate is low, if the reception strength at the access point 110 is not improved from that at the time of disconnection, the terminal 101 is not connected to the access point 110. can do. For this reason, it is possible to prevent the terminal 101 that is expected to improve the transmission rate from that at the time of disconnection from being connected to the access point 110.

  For this reason, fringes in the communication system 100 can be reduced, and the throughput of another wireless terminal connected to the access point 110 can be improved. Even in the disconnected terminal 101, throughput can be improved by connecting to a line different from the access point 110 having low reception strength.

  In another aspect, the communication control device 120 is a communication control device that performs connection control regarding the terminal 101 in response to a connection request including the reception strength from the terminal 101 (the reception level at the terminal 101). The control unit 122 disconnects the communication connection related to the terminal 101 when the transmission rate related to the terminal 101 falls below a predetermined reference. The communication control device 120 includes a storage unit that stores the reception intensity included in the reception request received from the terminal 101 when the control unit 122 disconnects the communication connection. The control unit 122 detects that a new connection request transmitted from the terminal 101 after disconnection of the communication connection related to the terminal 101 does not indicate a reception strength exceeding the reception strength of the terminal 101 stored in the storage unit of the communication control device 120. Then, the connection is not permitted for a new connection request.

  As a result, even if the terminal 101 disconnected from the access point 110 transmits a connection request (request signal) because the transmission rate is low, if the reception strength at the access point 110 is not improved from that at the time of disconnection, the terminal 101 It can be prevented from connecting. For this reason, it is possible to prevent the terminal 101 that is expected to improve the transmission rate from that at the time of disconnection from being connected to the access point 110.

  For this reason, fringes in the communication system 100 can be reduced, and the throughput of another wireless terminal connected to the access point 110 can be improved. Even in the disconnected terminal 101, throughput can be improved by connecting to a line different from the access point 110 having low reception strength.

  Further, the transmission format (modulation method) of the radio signal from the access point 110 to the terminal 101 may be adaptively changed. As the adaptively controlled transmission format, various formats such as QPSK (Quadrature Phase Shift Keying) and 16QAM (Quadrature Amplitude Modulation) can be used.

  In this case, the predetermined criterion compared with the transmission rate may be a transmission rate higher than a transmission rate that can be achieved with the slowest transmission format among the adaptively controlled transmission formats. As a result, although the communicable rate (minimum rate) is available, it is possible to prevent the terminal 101 having the lowest rate from continuing communication.

  Also, the adaptively controlled transmission format is selected according to the acquisition status of the reception acknowledgment from the terminal 101 for the data transmitted from the access point 110 to the terminal 101, for example. For example, the terminal 101 transmits ACK to the access point 110 when the data transmitted from the access point 110 can be normally received, and NACK when the data cannot be normally received. For example, the access point 110 changes the transmission format to QPSK or the like when the reception status of the ACK is not good (when the rate at which the ACK can be received falls below a predetermined standard in the transmission data), and the maximum transmission rate is Control in the decreasing direction.

(Embodiment 2)
In the second embodiment, a case where the communication control device 120 is provided in the access point 110 will be described.

(Access point according to the second embodiment)
FIG. 2 is a diagram of an example of an access point according to the second embodiment. As shown in FIG. 2, the access point 110 according to the second embodiment includes a transmission antenna 211, a reception antenna 212, a transmission circuit 221, a reception circuit 222, wireless LAN control software 230, and a terminal information storage unit 240. And including.

  The transmission circuit 221 wirelessly transmits a signal to a wireless terminal such as the terminal 101 via the transmission antenna 211. The reception circuit 222 receives a signal wirelessly transmitted from a wireless terminal such as the terminal 101 via the reception antenna 212.

  The wireless LAN control software 230 includes a transmission failure rate monitoring unit 231, a transmission rate management unit 232, an average transmission rate monitoring control unit 233, a connection frame reception availability control unit 234, and a black list management unit 235. The acquisition unit 121 and the control unit 122 illustrated in FIG. 1 can be realized by the average transmission rate monitoring control unit 233, for example.

  The transmission failure rate monitoring unit 231 determines the frame from the access point 110 to the terminal 101 on the basis of the number of frame transmissions from the access point 110 to the terminal 101 and the number of frame transmission failures from the access point 110 to the terminal 101. Monitor the transmission failure rate. Further, the transmission failure rate monitoring unit 231 notifies the transmission rate management unit 232 of the failure rate obtained by monitoring. The processing by the transmission failure rate monitoring unit 231 will be described later (see, for example, FIG. 6).

  When the failure rate notified from the transmission failure rate monitoring unit 231 is high, the transmission rate management unit 232 decreases the transmission rate from the access point 110 to the terminal 101. The transmission rate management unit 232 increases the transmission rate from the access point 110 to the terminal 101 when the failure rate of the terminal 101 is low. Further, the transmission rate management unit 232 notifies the average transmission rate monitoring control unit 233 of the transmission rate of the terminal 101. The processing by the transmission rate management unit 232 will be described later (see, for example, FIG. 7).

  The average transmission rate monitoring control unit 233 monitors the average transmission rate of the terminal 101 based on the transmission rate of the terminal 101 notified from the transmission rate management unit 232. Further, when the average transmission rate of the terminal 101 becomes less than the threshold value, the average transmission rate monitoring control unit 233 disconnects the terminal 101 from the access point 110 and also connects to the unconnected information management table 242 (quality monitoring black) in the terminal information storage unit 240. The terminal 101 is registered in the list. The processing by the average transmission rate monitoring control unit 233 will be described later (see, for example, FIG. 8).

  The connection frame reception availability control unit 234 discards the frame from the terminal 101 when the access point 110 receives a frame for connection to the access point 110 from the terminal 101 and the RSSI of the received frame is lower than the reference RSSI. .

  In addition, when the terminal 101 is registered in the unconnected information management table 242 (quality monitoring blacklist), the connection frame reception availability control unit 234 determines whether the terminal 101 has a RSSI of the received frame that is equal to or higher than the reference RSSI. If the RSSI has not improved from the previous connection, the received frame is discarded. The processing by the connection frame reception availability control unit 234 will be described later (see, for example, FIG. 9).

  Note that discarding the request signal is equivalent to the operation when the request signal does not reach the access point 110 when viewed from the terminal 101, and is not affected by the function of the terminal 101. Further, the same effect can be obtained by performing an operation of returning a rejection response instead of an operation of discarding the request signal.

  The black list management unit 235 periodically checks the unconnected information management table 242 (quality monitoring black list) of the terminal information storage unit 240, and an entry for which a predetermined time has elapsed after predetermined registration is stored in the unconnected information management table. Delete from 242 (quality monitoring blacklist). The processing by the black list management unit 235 will be described later (see, for example, FIG. 10).

  The terminal information storage unit 240 stores a connected terminal information management table 241 and an unconnected information management table 242. The connected terminal information management table 241 is a table indicating information (for example, a MAC address) regarding a wireless terminal connected to the access point 110. The unconnected information management table 242 is a quality monitoring black list indicating wireless terminals disconnected from the access point 110 due to a decrease in downlink transmission rate. The unconnected information management table 242 (quality monitoring blacklist) will be described later (see, for example, FIG. 4).

(Access point hardware configuration)
FIG. 3 is a diagram illustrating an example of a hardware configuration of the access point. The access point 110 shown in FIG. 2 can be realized by the communication device 300 shown in FIG. 3, for example. The communication device 300 includes a CPU 301, a RAM 302, a nonvolatile memory 303, a wired communication interface 304, and a wireless communication interface 305. The CPU 301, RAM 302, nonvolatile memory 303, wired communication interface 304, and wireless communication interface 305 are connected by a bus 309.

  A CPU 301 (Central Processing Unit) governs overall control of the communication apparatus 300. A RAM 302 (Random Access Memory) is used as a work area for the CPU 301. The nonvolatile memory 303 is a nonvolatile memory such as a magnetic disk or a flash memory. The nonvolatile memory 303 stores various programs for operating the communication device 300. The program stored in the nonvolatile memory 303 is loaded into the RAM 302 and executed by the CPU 301.

  The wired communication interface 304 is a communication interface that performs wired communication with the outside of the communication device 300 (for example, the Internet). The wired communication interface 304 is controlled by the CPU 301. The wireless communication interface 305 is a communication interface that performs wireless communication with the outside of the communication device 300 (for example, the terminal 101). The wireless communication interface 305 is controlled by the CPU 301.

  The transmission antenna 211, reception antenna 212, transmission circuit 221 and reception circuit 222 shown in FIG. 2 can be realized by the CPU 301 and the wireless communication interface 305, for example. The wireless LAN control software 230 shown in FIG. 2 can be realized, for example, by loading a program stored in the nonvolatile memory 303 into the RAM 302 and executing it by the CPU 301. The terminal information storage unit 240 shown in FIG. 2 can be realized by the RAM 302, for example.

(Quality monitoring blacklist)
FIG. 4 is a diagram illustrating an example of the quality monitoring black list. The quality monitoring black list 400 shown in FIG. 4 is an unconnected information management table 242 stored in the terminal information storage unit 240 shown in FIG. 2, for example. Each entry of the quality monitoring blacklist 400 includes a terminal MAC address, an average transmission rate [Mbps], an RSSI [dB], and a registration time (disconnection time). The average transmission rate [Mbps] may be omitted from the quality monitoring blacklist 400.

  The MAC address of the terminal is the MAC address of the terminal (for example, the terminal 101) disconnected from the access point 110 because the downlink transmission rate is low. The average transmission rate is an average transmission rate before disconnection of a terminal disconnected from the access point 110 because the downlink transmission rate is low.

  RSSI is RSSI before disconnection at the access point 110 from a terminal disconnected from the access point 110 because the downlink transmission rate is low. The registration time (disconnection time) is the time when the terminal is disconnected from the access point 110 because the downlink transmission rate is low (that is, the registration time in the quality monitoring blacklist 400).

(Message used to disconnect the terminal)
FIG. 5 is a diagram illustrating an example of a message used for disconnecting a terminal. When the transmission rate of the terminal 101 is low, the access point 110 disconnects the terminal 101 by transmitting, for example, an association release message 500 shown in FIG. The association cancellation message 500 includes, as parameters, Reason Code (reason for canceling connection relationship) and, if necessary, Vender Specific (vendor-specific definition information).

  For example, the terminal 101 can be disconnected by transmitting to the terminal 101 an association release message 500 in which “1: UNSPECIFED” is set as the setting value of Reason Code.

(Processing by the transmission failure rate monitoring unit)
FIG. 6 is a flowchart illustrating an example of processing performed by the transmission failure rate monitoring unit. The transmission failure rate monitoring unit 231 executes, for example, each step shown in FIG. First, the transmission failure rate monitoring unit 231 determines whether or not frame transmission to the terminal 101 has occurred by the transmission circuit 221 (step S601), and waits until frame transmission to the terminal 101 occurs (step S601: No). Loop).

  In step S601, when frame transmission to the terminal 101 occurs (step S601: Yes), the transmission failure rate monitoring unit 231 increments the number of transmissions for the terminal 101 (step S602). Next, the transmission failure rate monitoring unit 231 determines whether the reception circuit 222 has received an arrival confirmation response from the terminal 101 for frame transmission to the terminal 101 (step S603).

  In step S603, when an arrival confirmation response is received (step S603: Yes), the transmission failure rate monitoring unit 231 proceeds to step S606. If the arrival confirmation response has not been received (step S603: No), the transmission failure rate monitoring unit 231 increments the number of failures for the terminal 101 (step S604).

  Next, the transmission failure rate monitoring unit 231 determines whether or not the number of failures (number of retransmissions) for the terminal 101 has reached a predetermined number (step S605). If the number of failures has not reached the predetermined number (step S605: No), the transmission failure rate monitoring unit 231 returns to step S601.

  In step S605, when the number of failures reaches a predetermined number (step S605: Yes), the transmission failure rate monitoring unit 231 calculates a failure rate for the terminal 101 (step S606), and the process returns to step S601. In step S606, the transmission failure rate monitoring unit 231 calculates the failure rate for the terminal 101 by dividing the number of failures for the terminal 101 by the number of transmissions for the terminal 101 and multiplying by 100. When returning to step S601, the transmission failure rate monitoring unit 231 may initialize the number of failures and the number of transmissions for the terminal 101.

  Through the above steps, the failure rate of frame transmission from the access point 110 to the terminal 101 can be monitored. The transmission failure rate monitoring unit 231 notifies the transmission rate management unit 232 of the frame transmission failure rate from the access point 110 to the terminal 101.

(Processing by the transmission rate management unit)
FIG. 7 is a flowchart illustrating an example of processing performed by the transmission rate management unit. The access point 110 selects the initial transmission rate for the terminal 101 from the support rates of the terminal 101 notified from the terminal 101. For example, when the terminal 101 performs communication based on IEEE802.11b, the support rates of the terminal 101 are, for example, 1, 2, 5.5, and 11 [Mbps]. When the terminal 101 performs communication based on IEEE802.11g, the support rate of the terminal 101 is, for example, 1, 2, 5.5, 6, 9, 11, 12, 18, 24, 36, 48, and 54 [Mbps]. .

  For example, when the terminal 101 performs communication based on IEEE802.11b, the access point 110 sets 11 [Mbps], which is the highest rate among the support rates, as the initial transmission rate for the terminal 101.

  Further, when the terminal 101 performs communication based on IEEE 802.11g, the access point 110 sets 36 [Mbps] as the initial transmission rate for the terminal 101 even if the support rate includes 48 [Mbps] or higher. To do.

  Next, transmission rate update processing for the terminal 101 will be described. The transmission rate management unit 232 executes, for example, each step shown in FIG. First, the transmission rate management unit 232 determines whether or not frame transmission to the terminal 101 has occurred by the transmission circuit 221 (step S701), and waits until frame transmission to the terminal 101 occurs (step S701: No). loop).

  In step S701, when frame transmission to the terminal 101 occurs (step S701: Yes), the transmission rate management unit 232 proceeds to step S702. That is, the transmission rate management unit 232 determines whether or not a predetermined transmission rate calculation interval has elapsed since the last frame transmission to the terminal 101 (step S702), and until the transmission rate calculation interval elapses from the last frame transmission. Wait (step S702: No loop). The transmission rate calculation interval is, for example, 500 [ms].

  In step S702, when the transmission rate calculation interval has elapsed since the last frame transmission (step S702: Yes), the transmission rate management unit 232 proceeds to step S703. That is, the transmission rate management unit 232 determines whether or not the failure rate for the terminal 101 notified from the transmission failure rate monitoring unit 231 is larger than the threshold (step S703). When the failure rate for the terminal 101 is larger than the threshold (step S703: Yes), the transmission rate management unit 232 determines whether or not the transmission rate of the terminal 101 is already the lower limit value (step S704). The threshold is 33 [%], for example.

  In step S704, when the transmission rate is not the lower limit value (step S704: No), the transmission rate management unit 232 decreases the transmission rate of the terminal 101 by 1 (step S705), and returns to step S701. If the transmission rate is already the lower limit (step S704: Yes), the transmission rate management unit 232 returns to step S701 without changing the transmission rate of the terminal 101.

  In step S703, when the failure rate for the terminal 101 is equal to or less than the threshold (step S703: No), the transmission rate management unit 232 determines whether or not the transmission rate of the terminal 101 is already the upper limit value (step S703). S706). The threshold is, for example, 10 [%].

  In step S706, when the transmission rate is not the upper limit value (step S706: No), the transmission rate management unit 232 increases the transmission rate of the terminal 101 by 1 (step S707), and returns to step S701. When the transmission rate is the upper limit value (step S706: Yes), the transmission rate management unit 232 returns to step S701 without changing the transmission rate of the terminal 101.

  Through the above steps, the transmission rate from the access point 110 to the terminal 101 can be controlled based on the failure rate of the terminal 101.

(Processing by average transmission rate monitoring controller)
FIG. 8 is a flowchart illustrating an example of processing by the average transmission rate monitoring control unit. The average transmission rate monitoring control unit 233 executes, for example, each step shown in FIG. The average transmission rate monitoring control unit 233 determines whether or not the terminal 101 is connected to the access point 110 (step S801), and waits until the terminal 101 is connected to the access point 110 (step S801: No loop).

  In step S801, when the terminal 101 is connected to the access point 110 (step S801: Yes), the average transmission rate monitoring control unit 233 proceeds to step S802. That is, the average transmission rate monitoring control unit 233 determines whether or not the average transmission rate calculation interval has elapsed since the terminal 101 connected to the access point 110 (step S802), and until the average transmission rate calculation interval has elapsed. Wait (step S802: No loop). The average transmission rate calculation interval is, for example, 3 [s].

  In step S802, when the average transmission rate calculation interval elapses (step S802: Yes), the average transmission rate monitoring control unit 233 calculates the average transmission rate of the terminal 101 based on the transmission rate notified from the transmission rate management unit 232. (Step S803).

  Next, the average transmission rate monitoring control unit 233 determines whether or not the average transmission rate calculated in step S803 is less than a threshold (step S804). If the calculated average transmission rate is equal to or greater than the threshold (step S804: No), the average transmission rate monitoring control unit 233 returns to step S802.

  If the calculated average transmission rate is less than the threshold value in step S804 (step S804: Yes), the average transmission rate monitoring control unit 233 disconnects the terminal 101 from the access point 110 (step S805). In addition, the average transmission rate monitoring control unit 233 registers the terminal 101 in the quality monitoring blacklist 400 (step S806) and returns to step S801. The order of steps S805 and S806 may be changed.

  Through the above steps, when the average transmission rate of the terminal 101 becomes less than the threshold, the terminal 101 can be disconnected from the access point 110 and the terminal 101 can be registered in the quality monitoring blacklist 400.

(Processing by the connection frame reception control unit)
FIG. 9 is a flowchart illustrating an example of processing by the connection frame reception availability control unit. The connection frame reception availability control unit 234 executes, for example, each step shown in FIG. First, the connection frame reception availability control unit 234 determines whether the reception circuit 222 has received a frame from the terminal 101 (step S901), and waits until a frame is received from the terminal 101 (step S901: No). loop).

  In step S901, when a frame from the terminal 101 is received (step S901: Yes), the connection frame reception availability control unit 234 determines whether or not the received frame is a frame for connecting to the access point 110 ( Step S902). The frames for connecting to the access point 110 are, for example, a probe request frame, an authentication request frame, an association request frame, a reassociation request frame, and a retransmission frame thereof. If it is not a frame for connecting to the access point 110 (step S902: No), the connection frame reception availability control unit 234 returns to step S901.

  If it is a frame for connecting to the access point 110 in step S902 (step S902: Yes), the connection frame reception availability control unit 234 proceeds to step S903. That is, the connection frame reception availability control unit 234 determines whether or not the terminal 101 that is the transmission source of the received frame is registered in the quality monitoring blacklist 400 (step S903).

  In step S903, when registered in the quality monitoring blacklist 400 (step S903: Yes), the connection frame reception availability control unit 234 acquires the RSSI of the received frame. Then, the connection frame reception availability control unit 234 determines whether or not the acquired RSSI is greater than or equal to the reference RSSI (step S904). When the RSSI is less than the reference RSSI (step S904: No), the connection frame reception availability control unit 234 discards the received frame (step S905) and returns to step S901.

  If the RSSI is greater than or equal to the reference RSSI in step S904 (step S904: Yes), the connection frame reception availability control unit 234 acquires the RSSI at the time of the previous connection of the terminal 101 registered in the quality monitoring blacklist 400. Then, the connection frame reception availability control unit 234 determines whether or not the RSSI of the received frame is equal to or greater than the RSSI obtained by adding a predetermined improvement offset to the RSSI at the previous connection (step S906).

  In step S906, when the RSSI of the received frame is less than the RSSI obtained by adding the improvement offset to the RSSI at the previous connection (step S906: No), the connection frame reception availability control unit 234 proceeds to step S905. When the RSSI of the received frame is equal to or greater than the RSSI obtained by adding the improvement offset to the RSSI at the previous connection (step S906: Yes), the connection frame reception availability control unit 234 does not discard the received frame. As a result, a response frame is transmitted from the access point 110 to the terminal 101, and the terminal 101 connects to the access point 110.

  Next, the connection frame reception availability control unit 234 deletes the terminal 101 that is the transmission source of the received frame from the quality monitoring blacklist 400 (step S907), and returns to step S901.

  In step S903, when not registered in the quality monitoring black list 400 (step S903: No), the connection frame reception availability control unit 234 acquires the RSSI of the received frame. Then, the connection frame reception availability control unit 234 determines whether or not the acquired RSSI is greater than or equal to the reference RSSI (step S908).

  In step S908, when the acquired RSSI is less than the reference RSSI (step S908: No), the connection frame reception availability control unit 234 proceeds to step S905. When the acquired RSSI is equal to or higher than the reference RSSI (step S908: Yes), the connection frame reception availability control unit 234 returns to step S901 without discarding the received frame. As a result, a response frame is transmitted from the access point 110 to the terminal 101, and the terminal 101 connects to the access point 110.

  Through the above steps, even if the access point 110 receives a frame for connection to the access point 110 from the terminal 101, the frame can be discarded if the received frame has an RSSI lower than the reference RSSI. Further, when the terminal 101 is registered in the quality monitoring blacklist 400, the received frame is discarded if the RSSI of the received frame is equal to or higher than the reference RSSI unless the RSSI at the previous connection of the terminal 101 is improved. be able to.

(Processing by the blacklist manager)
FIG. 10 is a flowchart illustrating an example of processing performed by the blacklist management unit. The blacklist management unit 235 executes, for example, each step shown in FIG. First, the blacklist management unit 235 determines whether or not there is an entry in the quality monitoring blacklist 400 that has passed a predetermined time after a predetermined registration (step S1001). The predetermined time is, for example, 5 minutes.

  In step S1001, when there is no entry for which a predetermined time has elapsed after registration (step S1001: No), the blacklist management unit 235 proceeds to step S1002. That is, the black list management unit 235 determines whether or not a predetermined list monitoring interval has elapsed from step S1001 (step S1002), and waits until the list monitoring interval has elapsed (step S1002: No loop). When the list monitoring interval elapses (step S1002: Yes), the black list management unit 235 returns to step S1001.

  In step S1001, when there is an entry for which a predetermined time has elapsed after registration (step S1001: Yes), the blacklist management unit 235 deletes the entry for which the predetermined time has elapsed after registration from the quality monitoring blacklist 400. (Step S1003), the process proceeds to step S1002.

  Through the above steps, the quality monitoring blacklist 400 can be periodically checked, and entries for which a predetermined time has elapsed since registration can be deleted from the quality monitoring blacklist 400.

(Disconnecting connected devices)
FIG. 11 is a sequence diagram illustrating an example of disconnection of a connected terminal. In FIG. 11, a case will be described in which terminal 101 connected to access point 110 is disconnected due to a decrease in downlink transmission rate. In the example illustrated in FIG. 11, the threshold of the average transmission rate is 1.5 [Mbps].

  First, a connection is established between the access point 110 and the terminal 101 (step S1101). As a result, the access point 110 and the terminal 101 shift to a data transfer phase in which the terminal 101 transmits uplink data (Data) to the access point 110 and the access point 110 transmits downlink data (Data) to the terminal 101.

  In step S1101, the access point 110 acquires an average transmission rate (Ave Rate) from the access point 110 to the terminal 101. In step S1101, it is assumed that the average transmission rate is 2 [Mbps] and is equal to or higher than the threshold value of 1.5 [Mbps] (OK).

  After 3 [s] has elapsed from step S1101, the access point 110 acquires an average transmission rate from the access point 110 to the terminal 101 (step S1102). In step S1102, it is assumed that the average transmission rate is 2 [Mbps] and is equal to or higher than the threshold value of 1.5 [Mbps] (OK).

  After 3 [s] has elapsed from step S1102, the access point 110 acquires an average transmission rate from the access point 110 to the terminal 101 (step S1103). In step S1103, it is assumed that the average transmission rate is 2 [Mbps] and is equal to or higher than the threshold value of 1.5 [Mbps] (OK).

  Further, after step S1103, it is assumed that the propagation environment of downlink data from the access point 110 to the terminal 101 deteriorates and the transmission rate from the access point 110 to the terminal 101 decreases.

  After 3 [s] has elapsed from step S1103, the access point 110 acquires the average transmission rate from the access point 110 to the terminal 101 (step S1104). In step S1104, since the transmission rate from the access point 110 to the terminal 101 has decreased after step S1103, the acquired average transmission rate is 1 [Mbps], which is less than the threshold value of 1.5 [Mbps]. (NG).

  For this reason, the access point 110 disconnects (disassociates) the terminal 101 by transmitting a Dissociation (for example, the disassociation message 500 in FIG. 5) to the terminal 101.

  Then, the access point 110 adds the terminal MAC address of the disconnected terminal 101 to the quality monitoring black list 400. In addition, the access point 110 adds the RSSI of the last frame received from the terminal 101 and the disconnection time to the quality monitoring blacklist 400 together with the terminal MAC address of the disconnected terminal 101.

  In this way, the access point 110 periodically acquires the uplink transmission rate from the connected terminal 101 (for example, every 3 [s]), and monitors the average value of the acquired transmission rates. Then, when the average value of the transmission rates becomes less than a threshold value (for example, 1.5 [Mbps]), the access point 110 disconnects (disassociates) the terminal 101.

(Periodic monitoring of average transmission rate)
FIG. 12 is a diagram illustrating an example of regular monitoring of the average transmission rate. In FIG. 12, the horizontal axis indicates time. In the example illustrated in FIG. 12, the access point 110 monitors the transmission rate of the terminals A to C connected to the access point 110 with a cycle of 500 [ms], using a timer with a cycle of 500 [ms], for example. Each of the terminals A to C is a wireless terminal similar to the terminal 101. Further, the access point 110 calculates an average transmission rate by averaging the latest six transmission rates every 3 [s]. The average transmission rate monitoring threshold is set to 1.5 [Mbps].

  While the transmission rate is monitored at a cycle of 500 [ms], the update of the transmission rate of the terminal 101 by the access point 110 is performed when there is a frame transmission and 500 [ms] or more has elapsed since the previous frame transmission. This is carried out when there is a failure (see FIG. 7, for example). For this reason, transmission rate monitoring and transmission rate update are asynchronous.

  The transmission rates 1211 to 1213 indicate the acquisition results in the cycle of 500 [ms] of the downlink transmission rate between the terminals A to C and the access point 110, respectively. Average transmission rates 1221 to 1223 indicate the calculation results of the average transmission rate between the terminals A to C and the access point 110 in a period of 3 [s], respectively.

  For example, the access point 110 calculates the first average transmission rate 1201 for the terminal A when 3 [s] has elapsed since the timer was started. Since the average transmission rate 1201 is 13.3 [Mbps] and is equal to or higher than the average transmission rate monitoring threshold of 1.5 [Mbps], the access point 110 does not disconnect the terminal A. In addition, for the terminals B and C, the access points 110 do not calculate the average transmission rate and do not perform the disconnection control because the transmission rates for 6 times are not acquired when 3 [s] has elapsed after the timer is started.

  Next, the access point 110 calculates a second average transmission rate 1202 for the terminal A when 6 [s] has elapsed since the timer was started. Since the average transmission rate 1202 is 1.9 [Mbps], which is equal to or higher than the average transmission rate monitoring threshold of 1.5 [Mbps], the access point 110 does not disconnect the terminal A.

  Further, the access point 110 calculates the first average transmission rate 1203 for the terminal B when 6 [s] has elapsed after the timer is started. The average transmission rate 1203 is 1.8 [Mbps], which is equal to or higher than the average transmission rate monitoring threshold of 1.5 [Mbps], so that the access point 110 does not disconnect the terminal B.

  Further, the access point 110 calculates the first average transmission rate 1204 for the terminal C when 6 [s] has elapsed after the timer is started. Since the average transmission rate 1204 is 1 [Mbps], which is less than the average transmission rate monitoring threshold of 1.5 [Mbps], the access point 110 disconnects the terminal C. Further, the access point 110 adds the terminal C to the quality monitoring black list 400.

(Operation example of connection frame reception availability control)
FIG. 13 is a sequence diagram illustrating an operation example 1 of connection frame reception availability control. In FIG. 13, a case (part 1) in which a connection request frame from the terminal 101 that has no connection history with the access point 110 is discarded will be described.

  First, the access point 110 periodically wirelessly transmits a beacon (step S1301). The terminal 101 receives a beacon wirelessly transmitted from the access point 110, and transmits a probe request frame (Probe request) to the access point 110 (step S1302).

  When the access point 110 receives a probe request frame from the terminal 101, the access point 110 calculates an RSSI based on the received probe request frame. In the example illustrated in FIG. 13, the calculated RSSI is 19 [dB], which is less than 20 [dB] of the reference RSSI. For this reason, the access point 110 discards the probe request frame from the terminal 101.

  FIG. 14 is a sequence diagram illustrating an operation example 2 of connection frame reception availability control. In FIG. 14, a case (part 2) in which a connection request frame from the terminal 101 having no connection history with the access point 110 is discarded will be described.

  First, the access point 110 periodically wirelessly transmits a beacon (step S1401). The terminal 101 receives a beacon wirelessly transmitted from the access point 110, and transmits a probe request frame (Probe request) to the access point 110 (step S1402). When the access point 110 receives a probe request frame from the terminal 101, the access point 110 calculates an RSSI based on the received probe request frame. In the example illustrated in FIG. 14, since the calculated RSSI is 20 [dB] and is 20 [dB] or more of the reference RSSI, the access point 110 responds to the probe request frame from the terminal 101 (Probe response). Is transmitted (step S1403).

  Next, the terminal 101 transmits an authentication request frame (Authentication request) to the access point 110 (step S1404). When receiving the authentication request frame from the terminal 101, the access point 110 calculates an RSSI based on the received authentication request frame. In the example illustrated in FIG. 14, since the calculated RSSI is 19 [dB] and less than the reference RSSI of 20 [dB], the access point 110 discards the authentication request frame from the terminal 101.

  FIG. 15 is a sequence diagram illustrating operation example 3 of connection frame reception availability control. In FIG. 15, a case (part 3) in which a connection request frame from the terminal 101 that has no connection history with the access point 110 is discarded will be described.

  First, the access point 110 periodically wirelessly transmits a beacon (step S1501). The terminal 101 receives a beacon wirelessly transmitted from the access point 110 and transmits a probe request frame (Probe request) to the access point 110 (step S1502). When the access point 110 receives a probe request frame from the terminal 101, the access point 110 calculates an RSSI based on the received probe request frame. In the example illustrated in FIG. 15, the calculated RSSI is 20 [dB], which is 20 [dB] or more of the reference RSSI. Therefore, the access point 110 responds to a probe request frame from the terminal 101 (Probe response). Is transmitted (step S1503).

  Next, the terminal 101 transmits an authentication request frame (Authentication request) to the access point 110 (step S1504). When receiving the authentication request frame from the terminal 101, the access point 110 calculates an RSSI based on the received authentication request frame. In the example illustrated in FIG. 15, the calculated RSSI is 20 [dB], which is 20 [dB] or more of the reference RSSI. Therefore, the access point 110 responds to the authentication request frame from the terminal 101 (Authentication). response) is transmitted (step S1505).

  Next, the terminal 101 transmits an association request frame (association request) to the access point 110 (step S1506). When the access point 110 receives the association request frame from the terminal 101, the access point 110 calculates an RSSI based on the received association request frame. In the example illustrated in FIG. 15, since the calculated RSSI is 19 [dB] and less than the reference RSSI of 20 [dB], the access point 110 discards the association request frame from the terminal 101.

  FIG. 16 is a sequence diagram illustrating an operation example 4 of connection frame reception availability control. In FIG. 16, a case (part 4) in which a connection request frame from the terminal 101 having no connection history with the access point 110 is discarded will be described.

  Steps S1601 to S1606 shown in FIG. 16 are the same as steps S1501 to S1506 shown in FIG. In the example illustrated in FIG. 16, the RSSI based on the association request frame transmitted in step S1606 is 20 [dB], which is 20 [dB] or more of the reference RSSI. For this reason, the access point 110 transmits a response frame (association response) to the association request frame from the terminal 101 (step S1607).

  Next, the terminal 101 transmits a reassociation request frame (ReAssociation request) to the access point 110 (step S1608). When receiving the reassociation request frame from the terminal 101, the access point 110 calculates an RSSI based on the received reassociation request frame. In the example illustrated in FIG. 16, since the calculated RSSI is 19 [dB] and less than the reference RSSI of 20 [dB], the access point 110 discards the reassociation request frame from the terminal 101.

  FIG. 17 is a sequence diagram illustrating an operation example 5 of connection frame reception availability control. In FIG. 17, a case will be described in which the connection request frame from the terminal 101 disconnected by the access point 110 is discarded.

  First, a connection is established between the access point 110 and the terminal 101 (step S1701). As a result, the access point 110 and the terminal 101 shift to a data transfer phase in which the terminal 101 transmits uplink data (Data) to the access point 110 and the access point 110 transmits downlink data (Data) to the terminal 101.

  In the data transfer phase, it is assumed that the downlink data propagation environment from the access point 110 to the terminal 101 is deteriorated and the transmission rate from the access point 110 to the terminal 101 is reduced. The average transmission rate (Ave Rate) calculated by the access point 110 is 1.2 [Mbps], which is less than the threshold value of 1.5 [Mbps].

  In this case, the access point 110 transmits a Dissociation to the terminal 101 (step S1702), and disconnects (disassociates) the terminal 101. Further, the access point 110 adds information on the terminal 101 including RSSI (Last RSSI) from the terminal 101 at the access point 110 to the quality monitoring blacklist 400. In the example illustrated in FIG. 17, it is assumed that the Last RSSI is 35 [dB].

  Next, it is assumed that the terminal 101 transmits an authentication request frame (Authentication request) to the access point 110 in order to reconnect to the access point 110 (step S1703). When receiving the authentication request frame from the terminal 101, the access point 110 calculates an RSSI based on the received authentication request frame.

  In the example illustrated in FIG. 17, it is assumed that the calculated RSSI is 35 [dB], which is 20 [dB] or more of the reference RSSI. However, since the calculated RSSI of 35 [dB] is less than 38 [dB] obtained by adding the improvement offset of 3 [dB] to 35 [dB] of the Last RSSI, the access point 110 is connected to the terminal 101. The authentication request frame from is discarded.

  FIG. 18 is a sequence diagram illustrating an operation example 6 of connection frame reception availability control. In FIG. 18, a case will be described in which the RSSI for the terminal 101 disconnected by the access point 110 is improved and the terminal 101 reconnects to the access point 110.

  Steps S1801 to S1803 shown in FIG. 18 are the same as steps S1701 to S1703 shown in FIG. In the example illustrated in FIG. 18, since the RSSI of the authentication request frame transmitted in step S1803 is 34 [dB] and less than 38 [dB], the access point 110 receives the authentication request from the terminal 101. Discard the frame.

  Next, it is assumed that the terminal 101 transmits an authentication request frame (Authentication request) to the access point 110 in order to reconnect to the access point 110 (step S1804). Since the RSSI of the authentication request frame transmitted in step S1804 is 35 [dB] and less than 38 [dB], the access point 110 discards the authentication request frame from the terminal 101.

  Next, it is assumed that the terminal 101 transmits an authentication request frame to the access point 110 in order to reconnect to the access point 110 (step S1805). Since the RSSI of the authentication request frame transmitted in step S1805 is 36 [dB] and less than 38 [dB], the access point 110 discards the authentication request frame from the terminal 101.

  Next, it is assumed that the terminal 101 transmits an authentication request frame to the access point 110 in order to reconnect to the access point 110 (step S1806). Since the RSSI of the authentication request frame transmitted in step S1806 is 37 [dB] and less than 38 [dB], the access point 110 discards the authentication request frame from the terminal 101.

  After step S1806, it is assumed that the propagation environment between the access point 110 and the terminal 101 has improved and the RSSI from the terminal 101 at the access point 110 has greatly improved.

  Next, it is assumed that the terminal 101 transmits an authentication request frame to the access point 110 in order to reconnect to the access point 110 (step S1807). Since the RSSI of the authentication request frame transmitted in step S1807 is 40 [dB] and is 38 [dB] or more, the access point 110 does not discard the authentication request frame from the terminal 101.

  In this case, the access point 110 transmits a response frame (Authentication response) to the authentication request frame from the terminal 101 (step S1808). Further, the access point 110 deletes the entry of the terminal 101 from the quality monitoring blacklist 400.

  Next, the terminal 101 transmits an association request frame (association request) to the access point 110 (step S1809). When the access point 110 receives the association request frame from the terminal 101, the access point 110 calculates an RSSI based on the received association request frame.

  The RSSI of the association request frame transmitted in step S1809 is 40 [dB], which is 20 [dB] or more of the reference RSSI. For this reason, the access point 110 transmits a response frame (association response) to the association request frame from the terminal 101 (step S1810). Thereby, the connection between the access point 110 and the terminal 101 is established again.

  As described above, according to the communication control method, communication control program, and communication control apparatus of the present invention, throughput can be improved.

  For example, in a conventional WLAN, once connected, the connection state is maintained as long as communication is possible (until out-of-service is detected). For this reason, even if the throughput deteriorates after connection, the line is used unless the user using the terminal switches the connection destination. However, with the recent increase in WiFi devices, radio wave interference and congestion increase, and there are areas where stable throughput cannot be obtained despite strong electric fields.

  In addition, transmission from the access point to the terminal arrives without any problem, but transmission from the terminal to the access point is difficult to reach, and there is a fringe area where stable throughput cannot be obtained. In such an area, since a fringe event occurs in which transmission is delivered but a response is difficult to reach, good throughput may not be obtained in two-way communication (such as TCP) frequently used on the Internet.

  As a conventional technique, for example, a method of stabilizing the throughput after connection by improving the retransmission method or increasing the number of retransmissions can be taken, but this can only deliver transmission from the access point to the terminal more reliably. . In particular, in a situation where a fringe problem occurs such that it is difficult to receive a response from the terminal to the access point, the effect is not obtained, and a fringe event may be promoted.

  On the other hand, according to the communication control device 120, if the wireless LAN terminal cannot obtain transmission / reception throughput due to a fringe problem or the like, the quality cannot be ensured by performing early disconnection and performing quality monitoring even at the time of reconnection. The terminal can be guarded against being connected. As a result, a user who cannot obtain communication quality even when connected to a wireless LAN can be disconnected instantly. Therefore, a process of switching to another access point or a mobile line is executed on the terminal side. Users can get better throughput.

  The communication control method described in this embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. This program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer.

  The following additional notes are disclosed with respect to the above-described embodiments.

(Supplementary Note 1) A communication control method for controlling communication in a communication system in which an access point and a terminal are connected to be able to communicate with each other,
Obtaining a transmission rate from the access point to the terminal once or a plurality of times within a predetermined period;
Disconnecting communication between the access point and the terminal according to a value calculated based on the acquired transmission rate,
A communication control method characterized by the above.

(Supplementary note 2) The communication control method according to supplementary note 1, wherein the transmission rate is controlled in accordance with a degree of arrival of a signal from the access point to the terminal.

(Supplementary Note 3) When a request signal for connecting to the access point is transmitted from the terminal to the access point, the reception strength from the terminal at the access point is acquired,
Depending on the received reception strength, the access point discards the request signal.
The communication control method according to appendix 1 or 2, characterized in that:

(Supplementary Note 4) Correspondence Correspondence between Disconnected Terminal Disconnecting Communication with Access Point According to Value Calculated Based on Transmission Rate, and Reception Strength from Disconnected Terminal at Access Point Remember information,
When the request signal is transmitted from the disconnected terminal included in the stored correspondence information to the access point, the reception strength from the disconnected terminal at the access point is acquired,
Causing the access point to discard the request signal according to the difference between the acquired reception strength and the reception strength associated with the disconnected terminal in the stored correspondence information;
The communication control method according to Supplementary Note 3, wherein

(Supplementary note 5) When the acquired reception strength is less than a strength obtained by adding a predetermined amount to the reception strength associated with the disconnected terminal, the access point is made to discard the request signal. 5. The communication control method according to 4.

(Supplementary note 6) The supplementary note 4 or 5, wherein the correspondence information is deleted when the acquired reception strength is equal to or greater than a strength obtained by adding a predetermined amount to the reception strength associated with the disconnected terminal. The communication control method described.

(Supplementary Note 7) A computer that controls communication in a communication system in which an access point and a terminal are connected to be able to communicate with each other,
Obtaining a transmission rate from the access point to the terminal once or a plurality of times within a predetermined period;
Disconnecting communication between the access point and the terminal according to a value calculated based on the acquired transmission rate,
A communication control program for executing a process.

(Supplementary note 8) A communication control apparatus for controlling communication in a communication system in which an access point and a terminal are connected to be able to communicate with each other,
An acquisition unit for acquiring a transmission rate from the access point to the terminal once or a plurality of times within a predetermined period;
A control unit that disconnects communication between the access point and the terminal according to a value calculated based on the transmission rate acquired by the acquisition unit;
A communication control apparatus comprising:

(Supplementary note 9) A communication control apparatus that performs connection control on the wireless terminal in response to a connection request including reception strength from the wireless terminal,
A control unit that disconnects a communication connection related to the wireless terminal when a transmission rate related to the wireless terminal falls below a predetermined reference;
A storage unit for storing the reception strength when disconnecting the communication connection,
When the control unit detects that a new connection request transmitted from the wireless terminal after disconnecting the communication connection does not indicate a reception strength exceeding the stored reception strength, the control unit connects to the new connection request. Do not allow,
A communication control device.

(Additional remark 10) The said predetermined reference | standard is a transmission rate higher than the transmission rate achievable with the slowest transmission format among the transmission formats controlled adaptively, The additional description 9 characterized by the above-mentioned. Communication control device.

(Supplementary Note 11) The adaptively controlled transmission format is selected according to the acquisition status of reception acknowledgment from the wireless terminal for data transmitted to the wireless terminal. The communication control device according to attachment 10.

DESCRIPTION OF SYMBOLS 100 Communication system 101 Terminal 110 Access point 120 Communication control apparatus 121 Acquisition part 122 Control part 211 Transmission antenna 212 Reception antenna 221 Transmission circuit 222 Reception circuit 230 Wireless LAN control software 231 Transmission failure rate monitoring part 232 Transmission rate management part 233 Average transmission rate Monitoring control unit 234 Connection frame reception availability control unit 235 Blacklist management unit 240 Terminal information storage unit 241 Connection terminal information management table 242 Unconnected information management table 300 Communication device 301 CPU
302 RAM
303 Nonvolatile memory 304 Wired communication interface 305 Wireless communication interface 309 Bus 400 Quality monitoring blacklist 500 Association release message 1201-1204, 1221-1223 Average transmission rate 1211-1213 Transmission rate

Claims (8)

A communication control method for controlling communication in a communication system in which an access point and a terminal are communicably connected to each other,
Obtaining a transmission rate from the access point to the terminal once or a plurality of times within a predetermined period;
Disconnecting communication between the access point and the terminal according to a value calculated based on the acquired transmission rate,
A communication control method characterized by the above. When a request signal for connecting to the access point is transmitted from the terminal to the access point, the reception strength from the terminal at the access point is acquired,
Depending on the received reception strength, the access point discards the request signal.
The communication control method according to claim 1. Correspondence information that associates a disconnected terminal that has disconnected communication with the access point according to a value calculated based on the transmission rate and a reception intensity from the disconnected terminal at the access point is stored. ,
When the request signal is transmitted from the disconnected terminal included in the stored correspondence information to the access point, the reception strength from the disconnected terminal at the access point is acquired,
Causing the access point to discard the request signal according to the difference between the acquired reception strength and the reception strength associated with the disconnected terminal in the stored correspondence information;
The communication control method according to claim 2. To a computer that controls communication in a communication system in which an access point and a terminal are connected to be able to communicate with each other,
Obtaining a transmission rate from the access point to the terminal once or a plurality of times within a predetermined period;
Disconnecting communication between the access point and the terminal according to a value calculated based on the acquired transmission rate,
A communication control program for executing a process. A communication control device for controlling communication in a communication system in which an access point and a terminal are connected to be able to communicate with each other,
An acquisition unit for acquiring a transmission rate from the access point to the terminal once or a plurality of times within a predetermined period;
A control unit that disconnects communication between the access point and the terminal according to a value calculated based on the transmission rate acquired by the acquisition unit;
A communication control apparatus comprising: A communication control device that performs connection control on the wireless terminal in response to a connection request including reception strength from the wireless terminal,
A control unit that disconnects a communication connection related to the wireless terminal when a transmission rate related to the wireless terminal falls below a predetermined reference;
A storage unit for storing the reception strength when disconnecting the communication connection,
When the control unit detects that a new connection request transmitted from the wireless terminal after disconnecting the communication connection does not indicate a reception strength exceeding the stored reception strength, the control unit connects to the new connection request. Do not allow,
A communication control device.   The communication control apparatus according to claim 6, wherein the predetermined criterion is a transmission rate higher than a transmission rate achievable with the slowest transmission format among adaptively controlled transmission formats. .   8. The adaptively controlled transmission format is selected according to an acquisition status of a reception acknowledgment from the wireless terminal for data transmitted to the wireless terminal. The communication control device described.

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