JP6047792B2 - Wireless relay device, control method, and computer program - Google Patents

Description

  The present invention relates to a technique for performing wireless communication by selecting a channel to be used from a plurality of channels.

  Conventionally, wireless communication using a wireless local area network (LAN) has become widespread (see, for example, Patent Document 1). A specific example of the wireless LAN standard is IEEE 802.11b. In IEEE 802.11b, wireless communication is performed using one of 13 channels from 2.412 GHz (1ch) to 2.472 GHz (13ch).

If a plurality of different devices use the same channel at the same time, interference occurs and the speed of wireless communication decreases. In order to avoid such a problem, the access point of the wireless LAN measures the reception level of a beacon transmitted from another nearby access point, and uses a channel with a low reception level. By performing such an operation, the access point reduces the chance of occurrence of interference and suppresses the decrease in speed.
In Japan, 14 channels of 2.484 GHz can be used in IEEE802.11b wireless communication.

JP 2004-235976 A

  In recent years, the number of wireless LAN devices has increased, and the required communication speed has also increased. For this reason, there is a situation in which there is no empty channel and all channels are used by a plurality of access points. Such a problem is not limited to wireless communication using a wireless LAN, but is a problem common to techniques for performing wireless communication by selecting a channel from a plurality of channels.

  In view of the above circumstances, an object of the present invention is to provide a technique for suppressing a decrease in communication speed when wireless communication is performed by selecting a channel from a plurality of channels.

  One aspect of the present invention is based on an information collection unit that collects information about a time occupied by another communication device for each of a plurality of channels that can be used by the device, and information collected by the information collection unit. And a communication control unit that selects a channel with a low proportion of time occupied by other communication devices and controls to perform wireless communication using the selected channel.

  One aspect of the present invention is the above-described wireless communication apparatus, wherein the information collection unit measures a time occupancy ratio representing a ratio of time occupied by other communication apparatuses for each of the plurality of channels.

  One aspect of the present invention is the above-described wireless communication device, wherein the communication control unit calculates a statistical value of the time occupancy for each of the plurality of channels, and selects a channel based on the calculated statistical value. select.

  One aspect of the present invention is based on the information collection step of collecting information about the time occupied by other communication devices for each of a plurality of channels that can be used by the device, and the information collected in the information collection step And a communication control step of selecting a channel with a low proportion of time occupied by other communication devices and controlling to perform wireless communication using the selected channel.

  One aspect of the present invention is an information collection step for collecting information on a time occupied by another communication device for each of a plurality of channels that can be used by the device, and the information collection step. A communication control step of selecting a channel with a low percentage of time occupied by other communication devices based on the received information and controlling to perform wireless communication using the selected channel. It is a computer program.

  According to the present invention, it is possible to suppress a decrease in communication speed when performing wireless communication by selecting a channel from a plurality of channels.

It is a schematic block diagram showing the function structure of the radio | wireless communication apparatus which is one Embodiment of this invention. It is a figure which shows the specific example of the time occupation rate table which the time occupation rate memory | storage part 106 memorize | stores. 5 is a flowchart illustrating a specific example of a processing flow of the wireless relay device 100. It is a flowchart which shows the specific example of the flow of a process of the time occupation rate measurement part 105 at the time of operate | moving in a measurement mode. It is a flowchart which shows the specific example of the flow of the process which the communication control part 107 selects a channel. It is a graph showing the change of a throughput. The vertical axis represents the throughput. It is a figure which shows the specific example of the mail transmitted by the communication control part. It is a figure which shows the example of a display in the website for changing the setting of a channel.

  Hereinafter, a wireless communication apparatus according to an embodiment of the present invention will be described. FIG. 1 is a schematic block diagram showing a functional configuration of a wireless communication apparatus according to an embodiment of the present invention. Note that the wireless communication device in the following description is configured as the wireless relay device 100. However, the wireless communication device in the present invention is not necessarily implemented as a relay device, and may be configured as a wireless communication terminal.

  The wireless relay device 100 includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus. The wireless relay device 100 executes a wireless relay program, thereby performing a wireless communication unit 101, a wired communication unit 102, a communication information storage unit 103, a relay unit 104, a time occupancy measurement unit 105, a time occupancy storage unit 106, and a communication. It functions as a device including the control unit 107.

  The wireless communication unit 101 performs wireless communication with other communication devices by transmitting and receiving wireless signals. The wireless communication unit 101 performs wireless communication on one channel among a plurality of channels under the control of the communication control unit 107. For example, when the wireless relay device 100 is designed to operate according to the IEEE802.11b standard, the wireless communication unit 101 includes the 13 channels from 2.412 GHz (1ch) to 2.472 GHz (13ch). Wireless communication is performed using one channel.

The wired communication unit 102 performs wired communication by being connected to another communication device via a cable. For example, the wired communication unit 102 is connected to a communication facility provided in a main local network or the Internet.
The communication information storage unit 103 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The communication information storage unit 103 stores information (hereinafter referred to as “communication information”) related to one or more wireless communication terminals connected to the own device (wireless relay device 100). For example, information such as the MAC address, IP address, and SSID of each wireless communication terminal connected to the wireless relay device 100 is included in the communication information.

  The relay unit 104 relays data of signals received by the wireless communication unit 101 and the wired communication unit 102 toward a destination communication device. For example, the relay unit 104 receives a signal from a wireless communication terminal connected to its own device, and transfers the signal to the wired network via the wired communication unit 102 toward the destination communication device. For example, the relay unit 104 receives a signal from the wired network via the wired communication unit 102 and transfers the signal to the destination wireless communication terminal via the wireless communication unit 101.

  The time occupancy measurement unit 105 receives a radio signal existing around the own device through all the channels that can be used by the radio communication unit 101 via the radio communication unit 101. The time occupancy measuring unit 105 measures the ratio of other wireless communication devices occupying the channel (hereinafter referred to as “time occupancy”) for each channel according to the reception result. For example, the time occupancy rate measurement unit 105 determines a time during which a channel is occupied by another wireless communication device (hereinafter referred to as “occupation time”) during a predetermined time (hereinafter referred to as “measurement time”). Measurement may be performed, and the ratio between the occupation time and the measurement time may be calculated as the time occupation rate.

The time occupation rate storage unit 106 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The time occupancy storage unit 106 stores the results (time occupancy for each channel) measured by the time occupancy measurement unit 105 at each measurement time.
The communication control unit 107 controls the operation of the wireless relay device 100. For example, the communication control unit 107 controls the operation mode of the wireless relay device 100. The operation mode of the wireless relay device 100 includes a relay mode and a measurement mode. In the relay mode, the wireless relay device 100 performs a relay process as a normal relay device. That is, in the relay mode, the relay unit 104 mainly operates. On the other hand, in the measurement mode, the radio relay apparatus 100 receives a radio signal existing around the own apparatus and measures the time occupation rate. That is, in the measurement mode, the time occupancy measurement unit 105 mainly operates.

  Further, the communication control unit 107 calculates a statistical value of the time occupancy rate stored in the time occupancy rate storage unit 106, and determines a channel used by the own apparatus for wireless communication based on the statistical value. Then, the communication control unit 107 controls the wireless communication unit 101 to perform wireless communication using the determined channel.

  FIG. 2 is a diagram illustrating a specific example of the time occupancy rate table stored in the time occupancy rate storage unit 106. The time occupancy table is a table having a value of time occupancy for each channel for each measurement time. For example, in the measurement result at time t1, the time occupation ratio of channel 1 is 41%, and the time occupation ratio of channel 13 is 3%. For example, in the measurement result at time t2, the time occupation ratio of channel 1 is 56%, and the time occupation ratio of channel 13 is 7%.

  FIG. 3 is a flowchart illustrating a specific example of the processing flow of the wireless relay device 100. First, every time a predetermined timing arrives (step S101—YES), the communication control unit 107 has a terminal (hereinafter referred to as “connection terminal”) connected to the own apparatus (wireless relay apparatus 100). Whether or not (step S102). The communication control unit 107 determines the presence / absence of a connected terminal by referring to communication information stored in the communication information storage unit 103, for example.

  When there is no connection terminal (step S102-NO), the communication control unit 107 determines whether the wired communication unit 102 is connected to a session with another communication device (whether there is a wired communication being executed). (Step S103). When there is no wired communication being executed (step S104—NO), the communication control unit 107 controls the wireless relay device 100 to operate in the measurement mode (step S104).

  On the other hand, when it is not a predetermined timing (step S101-NO), when a connection terminal exists in the process of step S102 (step S102-YES), when wired communication exists in the process of step S103 (step S103-YES). In any case, the communication control unit 107 controls the wireless relay device 100 to operate in the relay mode (step S105).

  FIG. 4 is a flowchart showing a specific example of the processing flow of the time occupancy measuring unit 105 when operating in the measurement mode. When control is performed so that the communication control unit 107 operates in the measurement mode, the time occupancy measurement unit 105 first substitutes 1 for a variable i (step S201). Next, the time occupancy measuring unit 105 measures the time occupancy on the channel i (CHi) (step S202). Next, the time occupancy rate measuring unit 105 records the measurement result for channel i (CHi) in the time occupancy rate storage unit 106 (step S203).

  Next, the time occupancy measuring unit 105 determines whether or not the measurement of the time occupancy is completed for all the channels that can be used by the own device (step S204). Since the wireless relay device 100 according to the present embodiment operates based on IEEE 802.11b, the time occupancy measurement unit 105 determines whether the value of the variable i is smaller than 13. When there is an unmeasured channel, that is, when the value of the variable i is smaller than 13 (step S204—YES), the time occupancy measuring unit 105 increments the value of the variable i and returns to step S202. On the other hand, when there is no unmeasured channel, that is, when the value of the variable i is 13 or more (step S204—NO), the time occupancy measurement unit 105 ends the process.

  FIG. 5 is a flowchart illustrating a specific example of a flow of processing in which the communication control unit 107 selects a channel. The communication control unit 107 does not select a channel until a predetermined timing arrives (step S301—NO). The predetermined timing may be any timing as long as it is the same as or longer than the timing of step S101. For example, the timing at step S301 may be the timing at which the process proceeds to NO in the process at step S204 in FIG.

  When the predetermined timing arrives (step S301-YES), the communication control unit 107 calculates a statistical value of the time occupancy rate (step S302). The statistical value may be any statistical value as long as it is an effective value for detecting a channel having a large time occupation rate. For example, the statistical value may be an average value of time occupancy within a predetermined time, or may be a maximum value of time occupancy within a predetermined time, or each time occupancy within a predetermined time. It may be an average value obtained by multiplying the rate by a weight. As a specific example of the weighting, a larger value may be used as the measurement result is closer to the current time, and a smaller value may be used as the measurement result is farther from the current time.

  Next, the communication control unit 107 selects a channel to be used in the own device based on the calculated statistical value. For example, the communication control unit 107 selects a channel corresponding to the smallest statistical value among the calculated statistical values (step S303). The communication control unit 107 determines whether the currently used channel (hereinafter referred to as “used channel”) is different from the channel selected in the process of step S303 (hereinafter referred to as “selected channel”). (Step S304).

  When the in-use channel matches the selected channel (NO in step S304), the communication control unit 107 ends the process illustrated in FIG. 5 without performing any subsequent process. On the other hand, when the used channel and the selected channel are different (step S304—YES), the communication control unit 107 performs a channel change process (step S305). When the channel control process is started, the communication control unit 107 confirms whether there is a connected terminal, and changes the channel to the selected channel when there is no connected terminal. And the communication control part 107 complete | finishes the process shown by FIG.

  In the wireless relay device 100 configured as described above, the time occupancy is used as a determination criterion when a channel to be used is selected from a plurality of channels. Therefore, for example, it is possible to accurately avoid a channel that may cause a decrease in communication speed as compared with a case where the reception level of Beacon is used as a criterion.

  FIG. 6 is a graph showing changes in throughput. The vertical axis represents the throughput. The left bar graph represents a throughput value when wireless communication is performed in a state where there is no other communication device using the same channel. The center bar graph represents the value of the throughput when wireless communication is performed in a state where there is another communication device that transmits the Beacon using the same channel. In the state indicated by the central bar graph, other communication devices (AP) transmit Beacon, but do not wirelessly communicate data with subordinate wireless communication terminals (STAs). The bar graph on the right represents the throughput value when wireless communication is performed in a state where there is another communication device that performs wireless communication using the same channel. In the state indicated by the right bar graph, the other communication device (AP) performs wireless communication of data with the subordinate wireless communication terminal (STA).

  As is clear from FIG. 6, even if there is another communication device that performs wireless communication using the same channel, the other communication device simply transmits a Beacon. For example, the throughput hardly decreases. This is because the time occupied by Beacon transmission is much shorter than the time occupied when general data is transmitted.

  On the other hand, when other communication devices are performing wireless data communication, the throughput is greatly reduced. Therefore, when the reception level of Beacon is used as a criterion, there is a possibility that a channel on which data is communicated is selected rather than a channel on which only Beacon is transmitted. On the other hand, in the wireless relay device 100, as described above, the time occupancy is used as a determination criterion. Therefore, if only the Beacon is transmitted, it is selected as a channel that is actively used.

  In addition, it is possible to improve the system throughput from the viewpoint of system throughput in a radio communication system including a plurality of radio relay apparatuses 100. In other words, it is possible to improve the channel usage efficiency by effectively transmitting and receiving data in the channel where only Beacon is transmitted.

<Modification>
The communication control unit 107 of the wireless relay device 100 may operate as follows when the process proceeds to YES in the process of step S304.
First, the communication control unit 107 transmits an e-mail having a content prompting a channel setting change to a pre-set e-mail address. FIG. 7 is a diagram illustrating a specific example of mail transmitted by the communication control unit 107. The mail text may include a link to a website where channel settings can be changed. When the user who receives the mail clicks or taps a link on the communication terminal, the communication terminal accesses a website for changing channel settings.

  FIG. 8 is a diagram showing a display example on a website for changing channel settings. On the website screen, a button for instructing to change channel settings (“Yes” button) and a button for instructing not to change channel settings (“No” button) are displayed. Is done. When the user who has received the mail clicks or taps the “Yes” button on the communication terminal, the communication control unit 107 of the wireless relay device 100 executes the channel change process shown in step S305.

  The flowcharts shown in FIGS. 3-5 are merely examples. For example, the condition for starting the operation in the measurement mode (step S104) may be determined based only on the presence / absence of a connected terminal regardless of the presence / absence of wired communication. That is, when the process proceeds to NO in the process of step S102 in FIG. 3, the measurement mode operation may be executed. The channel change process may be performed in any way.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Wireless relay apparatus, 101 ... Wireless communication part, 102 ... Wired communication part, 103 ... Communication information storage part, 104 ... Relay part, 105 ... Time occupation rate measurement part (information collection part), 106 ... Time occupation rate storage part 107: Communication control unit

Claims (5)

An information collection unit that collects information about the time occupied by other communication devices for each of a plurality of channels that can be used by the device;
Based on the information collected by the information collection unit, the user as the percentage of time occupied selects a lower channel, performs wireless communication by changing the channel selected channel used by another communication device A communication control unit for sending an email prompting to a preset email address ;
Equipped with a,
The mail transmitted by the communication control unit is a wireless relay device including a link to a website capable of changing a setting of a use channel . The radio relay apparatus according to claim 1, wherein the information collection unit measures a time occupancy ratio representing a ratio of time occupied by another communication apparatus for each of the plurality of channels. The radio relay apparatus according to claim 2, wherein the communication control unit calculates a statistical value of the time occupancy rate for each of the plurality of channels, and selects a channel based on the calculated statistical value. An information collecting step in which the wireless relay device collects information on the time occupied by other communication devices for each of a plurality of channels that can be used by the device;
Based on the information collected in the information collecting step, the wireless relay device selects a channel with a low percentage of time occupied by other communication devices , changes the used channel to the selected channel, and performs wireless communication. A communication control step of transmitting an email prompting the user to perform to a preset email address ;
I have a,
The mail transmitted by the communication control unit includes a link to a website capable of changing a setting of a use channel . An information collection unit that collects information about the time occupied by other communication devices for each of a plurality of channels that can be used by the device;
Based on the information collected by the information collecting unit, the user selects a channel with a low percentage of time occupied by other communication devices, changes the used channel to the selected channel, and performs wireless communication. A communication control unit for sending an email prompting to a preset email address;
With
The mail transmitted by the communication control unit is a computer program for causing a computer to function as a wireless relay device including a link to a website capable of changing the setting of a use channel .

Images