JP2016111591A - Radio communication device and method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication device or the like for suppressing an interruption (standby) time of radio communication in a communication band having a priority radio wave, such as a radar wave.SOLUTION: The radio communication device includes a first reception part and a second reception part which can receive radio waves, a detection control part for surveying a prescribed radio wave through the first reception part in each channel in a prescribed communication band, and recording detection result information representing each channel in which the prescribed radio wave is detected, a channel monitoring control part for selecting any one of non-detection channels in which the prescribed radio wave is not detected as a monitoring channel on the basis of the detection result information, and monitoring the existence/absence of the prescribed radio wave to be transmitted to the monitoring channel through the second reception part, a communication part which can transmit/receive data, and a communication control part for starting data communication to the monitoring channel through the communication part in the case that radio waves are not detected for a prescribed period or more in the monitoring channel when starting the data communication to a new channel.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a communication efficiency improvement technique in a wireless communication device.

  In a wireless communication network, a general radio wave such as data communication and a priority radio wave obliged to be given priority may share the same frequency band (communication band). At this time, a wireless communication apparatus that performs general data communication is required to avoid interference with a priority radio wave.

  For example, in a 5 GHz band called W53 and W56 used by a wireless LAN (local area network) access point, radars for weather, aircraft, military use, etc. use the same band. Radar waves transmitted and received by these radars are one of the priority radio waves. When the wireless LAN and radar share the 5 GHz band, the wireless LAN access point must be equipped with a dynamic frequency selection function called DFS (Dynamic Frequency Selection) to avoid radio wave interference with various radar waves. .

  The DFS includes functions such as CAC (Channel Availability Check) and ISM (In Service Monitoring). According to CAC, a wireless LAN access point must first monitor a radar wave for one minute on a channel to be used before starting communication. The wireless LAN access point can start communication on the channel when no radar is detected during that time. In ISM, a wireless LAN access point is required to constantly monitor radar waves on the channel during communication. When a radar wave is detected during communication, the wireless LAN access point must stop using the channel within 10 seconds. After stopping using the channel, the wireless LAN access point monitors another channel for 1 minute, and if no radar wave is detected during that time, it can move to that channel (avoid radar wave).

  As described above, when a wireless LAN access point detects a radar wave during communication, there is a problem that communication cannot be performed (interrupted) for at least one minute. In addition, when a radar wave is detected on another newly monitored channel, the wireless LAN access point performs CAC on yet another channel, which causes a problem that the communication interruption time increases to 1 minute or more. . This also appears as a problem that even when the wireless LAN access point newly starts communication, it cannot start communication for at least one minute.

  To deal with such a problem, for example, Patent Document 1 discloses a wireless communication device that changes a channel without interrupting data communication when changing the channel to a frequency at which a specific priority radio wave exists. The wireless communication device described in Patent Document 1 includes two transmission / reception circuits, and normally performs data communication using the two transmission / reception circuits. When this wireless LAN access point detects a radar wave, the wireless LAN access point performs CAC with another transmission / reception circuit while continuing data communication with the one transmission / reception circuit.

Patent Document 2 discloses a wireless communication device having a monitor (CAC) system separately from a communication system. The wireless communication device described in Patent Document 2 monitors another channel capable of communication by the monitoring system while the communication system performs data communication.
And when this radio communication device detects radar radio waves in the channel being communicated, if it does not detect radar radio waves for one minute in the channel being monitored, it communicates in the channel being monitored. Can be resumed promptly. If a radar wave is detected within one minute on the monitored channel (there is no channel that has been CACed), this wireless communication device performs CAC on the new channel in the communication system. The communication is resumed using the communicable channel found by (1).

  Patent Document 3 discloses a wireless LAN device that performs the same method as Patent Document 2 without providing a dedicated monitor circuit. The wireless LAN device described in Patent Document 3 can realize the same function as Patent Document 2 by temporarily using one of the four wireless transmission / reception circuits for radar wave detection. .

  Further, Patent Document 4 discloses an in-vehicle wireless communication apparatus that determines a switching destination channel using information on collected clear channels (channels that do not interfere with each other). The communication means in the wireless communication apparatus described in Patent Document 4 collects information on other systems that detect radio waves and detects a clear channel by monitoring performed while the wireless communication apparatus is not communicating. Then, the channel switching control means registers the collected information and clear channel information in the system data. After that, when channel switching becomes necessary, the communication means selects a channel that is highly unlikely to cause interference based on the system data, and resumes communication after performing CAC on the channel. Can do.

JP2011-146945A JP 2010-278825 A JP 2012-120033 A International Publication No. 2013/17997

  However, the wireless communication device described in Patent Document 1 has a problem that communication is always interrupted for a certain time or more when the channel is switched after the radar wave is detected. The reason is that, according to regulations, communication must be stopped within 10 seconds after the detection of the radar wave, so that the wireless communication device must be at least 50 seconds or more during the 1-minute monitoring that starts after the detection of the radar wave. This is because communication must be interrupted.

In addition, in the wireless communication device and the wireless LAN device described in Patent Documents 2 and 3, when the monitoring destination is changed because a radar wave is detected in the channel being monitored, the next available channel is set. It may take a long time to prepare. The reason for this is that when changing the monitoring destination, a new channel is selected without any knowledge, and there is a possibility that a channel that cannot be used may be used as the monitoring destination. As a result, in these apparatuses, there is a problem that the possibility of switching the communication channel for performing normal communication increases while the channel that has been monitored for one minute has not been prepared. That is, these devices have a problem that the communication channel is switched while a monitored channel is not prepared, and then the communication is interrupted to monitor again for one minute. is there.
Further, in the wireless communication device described in Patent Document 4, since the CAC for one minute is started when the communication unit performs channel switching, the problem that communication is interrupted is not solved.

  One object of the present invention is to provide a wireless communication apparatus and the like that can suppress the interruption (standby) time of wireless communication in a communication band in which there is priority radio waves such as radar waves.

  In order to achieve the above object, a wireless communication apparatus according to one embodiment of the present invention includes the following configuration.

That is, a wireless communication device according to one embodiment of the present invention is provided.
First receiving means capable of receiving radio waves;
Detection control means for searching for a predetermined radio wave via the first receiving means for each channel in a predetermined communication band, and recording detection result information representing each channel in which the predetermined radio wave is detected;
A second receiving means capable of receiving radio waves;
Based on the detection result information, select one of the non-detection channels that is a channel in which the predetermined radio wave has not been detected as a monitoring channel, Channel monitoring control means for monitoring the presence or absence of a predetermined radio wave transmitted,
A communication means capable of transmitting and receiving data;
When data communication is started for a new channel, if the radio wave is not detected for a predetermined period or longer in the monitoring channel, the data communication is started for the monitoring channel via the communication means. Communication control means.

In order to achieve the above object, a wireless communication method according to an aspect of the present invention is performed by a computer.
Search for a predetermined radio wave for each channel in a predetermined communication band via the first receiving means,
Recording detection result information representing each channel in which the predetermined radio wave is detected,
Based on the detection result information, select any one of the non-detection channels that are channels in which the predetermined radio wave is not detected as a monitoring channel,
Monitoring the presence or absence of a predetermined radio wave transmitted to the monitoring channel via the second receiving means;
When starting data communication for a new channel,
If the radio wave has not been detected for a predetermined period or longer in the monitoring channel, the data communication is started to the monitoring channel via a communication means capable of transmitting and receiving.

  The object is also achieved by a wireless communication device having each of the above-described configurations and a corresponding method by a computer program realized by a computer, and a computer-readable storage medium storing the computer program. Is done.

  The present invention has an effect that the interruption (standby) time of wireless communication can be suppressed in a communication band having a priority radio wave such as a radar wave.

It is a block diagram which shows the structure of the radio | wireless communication apparatus 1 which concerns on the 1st Embodiment of this invention. It is a block diagram which shows an example of the communication environment in the radio | wireless communications system which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the wireless LAN access point (wireless communication apparatus) 100 which concerns on 2nd Embodiment. It is a flowchart which shows the electromagnetic wave detection operation | movement which the electromagnetic wave detection control part 112 controls in 2nd Embodiment. It is a flowchart which shows the channel monitoring operation | movement which the channel monitoring control part 113 controls in 2nd Embodiment. It is a flowchart which shows the data communication operation | movement which the communication control part 111 controls in 2nd Embodiment. It is a figure which shows an example of the electromagnetic wave detection table 171 in 2nd Embodiment. It is a figure which shows an example of the electromagnetic wave detection table 171 in 2nd Embodiment. It is a figure which illustrates the structure of the computer (information processing apparatus) applicable to each embodiment of this invention and the radio | wireless communication apparatus which concerns on the modification, and a radio | wireless communications system.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
FIG. 1 is a block diagram showing a configuration of a wireless communication apparatus 1 according to the first embodiment of the present invention. Referring to FIG. 1, a wireless communication device 1 according to the present embodiment includes a first receiving unit 2, a radio wave detection control unit 3, a second receiving unit 4, a channel monitoring control unit 5, a communication unit 6, and a communication control unit. 7 and a storage device 8.

  Each unit of the wireless communication device 1 may be configured by a dedicated hardware device or a logic circuit. Alternatively, the wireless communication device 1 is configured by a general information processing device (computer) that operates under the control of a computer program (software program) executed using a CPU (Central Processing Unit: not shown). Also good. A hardware configuration example in which the wireless communication device 1 is realized by a computer will be described later with reference to FIG.

  The wireless communication device 1 can wirelessly communicate with an external device (not shown) via the wireless network 1001.

  The first receiving unit 2 can receive a radio wave having a frequency specified by the radio wave detection control unit 3.

  The radio wave detection control unit 3 searches for a predetermined radio wave via the first reception unit 2 for each channel in a predetermined communication band. Then, the radio wave detection control unit 3 records detection result information 9 representing each channel in which a predetermined radio wave is detected in the storage device 8. For example, the radio wave detection control unit 3 may sequentially search for channels in the communication band (W53 and W56) of 5 GHz where the radar wave needs to be prioritized via the first reception unit 2. When a radar wave is detected in a certain channel, the radio wave detection control unit 3 records that a predetermined radio wave is detected in that channel as detection result information 9 and then searches for the next channel.

  The storage device 8 can store the detection result information 9. The storage device 8 is realized by, for example, a semiconductor memory device or a disk device.

  The second receiving unit 4 can receive a radio wave having a frequency specified by the channel monitoring control unit 5.

  Based on the detection result information 9, the channel monitoring control unit 5 selects any one of the non-detection channels that are channels in which a predetermined radio wave has not been detected as a monitoring channel. Then, the channel monitoring control unit 5 monitors the presence / absence of a predetermined radio wave transmitted to the selected monitoring channel via the second receiving unit 4. For example, the channel monitoring control unit 5 can select any channel as a monitoring channel excluding the channel in which the radar wave is detected based on the detection result information 9 recorded by the radio wave detection control unit 3. Then, the channel monitoring control unit 5 monitors the selected monitoring channel via the second receiving unit 4. When a radar wave is detected in the monitoring channel, the channel monitoring control unit 5 can select a new monitoring channel and perform monitoring in the new monitoring channel.

  The communication unit 6 can transmit and receive data designated by the communication control unit 7.

  When the communication control unit 7 starts data communication for a new channel, if the predetermined radio wave is not detected for a predetermined period or longer in the monitoring channel monitored by the channel monitoring control unit 5, the communication control unit 7 Data communication is started to the channel via the communication unit 6. That is, the communication control unit 7 can perform the above-described operation when newly starting data communication or when stopping the use of the channel performing data communication and changing to a new channel. . For example, the communication control unit 7 first detects a radar wave for a predetermined period (for example, 1 minute) or longer in the monitored channel by inquiring the channel monitoring control unit 5 or the like. Make sure. Then, the communication control unit 7 starts data communication via the communication unit 6 for the monitoring channel. At this time, since it has already been confirmed that the radar channel has not detected a radar wave for one minute or longer, the communication control unit 7 can immediately start data communication in the monitoring channel.

  As described above, the present embodiment has an effect that wireless communication interruption (standby) time can be suppressed in a communication band in which priority radio waves such as radar waves are present. Note that, in the case of newly starting wireless communication, this embodiment has an effect that the waiting time until the start of wireless communication can be suppressed.

  The reason is that the radio wave detection control unit 3 records the detection result information 9 that a predetermined radio wave is detected in the search for each channel of the communication band. This is because the channel monitoring control unit 5 can monitor a channel with a low possibility of detecting a radio wave by avoiding a channel in which the radio wave is detected based on the detection result information 9.

  That is, when the communication control unit 7 needs a new channel, it is highly likely that the channel monitoring control unit 5 has secured a channel that has been confirmed that no radio wave has been detected for a predetermined period of time. I can say that. Accordingly, when the communication control unit 7 starts data communication with respect to a new channel, there is a possibility that the communication control unit 7 can quickly start communication using the channel monitored by the channel monitoring control unit 5 for a predetermined period or more. Can be expected to increase.

<Second Embodiment>
Next, a second embodiment based on the above-described first embodiment will be described. The following description will focus on the characteristic parts according to the second embodiment, and a detailed description overlapping with the components of the second embodiment having the same configuration as that of the first embodiment will be omitted.

  FIG. 2 is a block diagram showing the configuration of the wireless LAN system according to the first embodiment of the present invention. Referring to FIG. 2, the wireless LAN system according to the present embodiment includes a wireless LAN access point (wireless communication apparatus) 100, a wireless LAN slave device 200, a broadband modem 300, and a radar 500.

  The wireless LAN access point 100 is based on the wireless communication device 1 according to the first embodiment. In the present embodiment, a case where the present invention is applied to a dual-band wireless LAN access point 100 of 5 GHz band and 2.4 GHz band will be described as an example.

  In addition, the wireless LAN access point 100, the wireless LAN slave device 200, and the radar 500 have communication bands in a 5 GHz band called W53 and W56 (hereinafter, W53 and W56 are collectively referred to as “5 GHz band”). Sharing. Accordingly, the wireless LAN access point 100 and the wireless LAN slave device 200 are required to give priority to the radar wave transmitted and received by the radar 500 by the DFS function as described above in the background art section. That is, the wireless LAN access point 100 according to the present embodiment has a configuration in which the “predetermined communication band” that is the operation target of the wireless communication apparatus 1 according to the first embodiment is set to the “5 GHz band” as an example. In addition, the wireless LAN access point 100 in the present embodiment is a form in which “predetermined radio waves” that are to be operated by each unit of the wireless communication device 1 in the first embodiment are “radar waves” as an example. . Note that the wireless LAN access point 100 does not apply the present invention because DFS is not required for communication in the 2.4 GHz band.

  The wireless LAN slave device 200 can be connected to the Internet 1002 via the wireless LAN access point 100 and the broadband modem 300. The wireless LAN access point 100 and the wireless LAN slave device 200 can perform wireless communication in communication bands (frequency bands) of 2.4 GHz and 5 GHz. The wireless LAN access point 100 and the broadband modem 300 can communicate via a wired communication network such as a local area LAN.

  Each unit of the wireless LAN access point 100, the wireless LAN slave device 200, the broadband modem 300, and the radar 500 may be configured by a dedicated hardware device or a logic circuit. Alternatively, the wireless LAN access point 100, the wireless LAN slave unit 200, the broadband modem 300, and the radar 500 are controlled by a computer program (software program) that is executed using a CPU (Central Processing Unit: not shown). You may comprise by the general information processing apparatus (computer) which operate | moves. A hardware configuration example in which the wireless LAN access point 100 is realized by a computer will be described later with reference to FIG.

  The wireless LAN access point 100 can operate as a dual-band wireless LAN access point of 5 GHz and 2.4 GHz. The configuration of the wireless LAN access point 100 according to the present embodiment will be described below with reference to FIG. FIG. 3 is a block diagram illustrating a configuration of a wireless LAN access point (wireless communication apparatus) 100 according to the second embodiment. Referring to FIG. 3, the wireless LAN access point 100 includes a communication control unit 111, a radio wave detection control unit 112, a channel monitoring control unit 113, a communication unit (5 GHz) 120, a communication unit (2.4 GHz) 130, and a first reception. Unit 140, second receiving unit 150, wired WAN (Wide Area Network) / LAN control unit 160, and storage device 170. The storage device 170 can store a radio wave detection table 171.

  The storage device 170 is based on the storage device 8 in the first embodiment. The storage device 170 is realized by, for example, a semiconductor memory device or a disk device.

  The radio wave detection table 171 is based on the detection result information 9 according to the first embodiment. In the present embodiment, as an example, the radio wave detection table 171 includes, for each channel in the 5 GHz band, in addition to a “channel” column and a “radio wave detection” column corresponding to the detection result information 9, a “used channel” column, And a “monitoring channel” column.

  The “channel” column can store channel information representing a channel. The “radio wave detection” column can store information indicating the detection state of radio waves (radar waves) in the channel corresponding to the “channel” column. The “used channel” column can store information indicating a channel used by the communication control unit 111 for data communication. The “monitoring channel” column can store information indicating that the CAC by the channel monitoring controller 113 is completed and the channel corresponding to the “channel” column is available. As described above in the background art section, the CAC is an operation for confirming that a preferred radio wave (radar wave) is not detected for 1 minute or more by monitoring a channel used for data communication before performing data communication. It is. In this specification, a channel that has been subjected to CAC is also referred to as an “available channel”.

  The first receiving unit 140 corresponds to the first receiving unit 2 in the first embodiment. The second receiving unit 150 corresponds to the second receiving unit 4 in the first embodiment. In this embodiment, the 1st receiving part 140 and the 2nd receiving part 150 can receive the electromagnetic wave in all the channels of 5 GHz band as an example. Each of the first receiving unit 140 and the second receiving unit 150 includes a pair of 5 GHz antennas 142 (152) and a receiving circuit 141 (151).

  Each of the 5 GHz antennas 142 and 152 can individually receive a 5 GHz band radio wave. The receiving circuits 141 and 151 are general receiving circuits that can receive 5 GHz band radio waves. The receiving circuits 141 and 151 have various functional circuits called MAC (Medium Access Control), BB (Baseband), RF (Radio Frequency), LNA (Low Noise Amplifier), and the like. Since the reception circuits 141 and 151 can employ a well-known general technique, detailed description in this embodiment will be omitted.

A communication unit (5 GHz) 120 (hereinafter simply referred to as “communication unit 120”) corresponds to the communication unit 6 in the first embodiment. In this embodiment, the communication part 120 can transmit / receive in all the channels of 5 GHz band as an example. The communication unit 120 includes a 5 GHz antenna 122 and a transmission / reception circuit 121.
The 5 GHz antenna 122 can transmit and receive 5 GHz band radio waves. The transmission / reception circuit 121 is a general transmission / reception circuit capable of transmitting / receiving 5 GHz band radio waves. The transmission / reception circuit 121 includes, for example, a PA (Power Amplifier) and a transmission / reception changeover switch in addition to a circuit similar to the reception circuit 141 or 151. Since the transmission / reception circuit 121 can employ a well-known general technique, a detailed description in this embodiment is omitted.

  A communication unit (2.4 GHz) 130 (hereinafter simply referred to as “communication unit 130”) realizes transmission / reception in the 2.4 GHz band in addition to the 5 GHz band as a dual-band wireless LAN access point. The communication unit 130 is an element that is not included in the first embodiment. The communication unit 130 includes a 2.4 GHz antenna 132 and a transmission / reception circuit 131. Since the configuration of the communication unit 130 is the same as the configuration of the communication unit 120 except that the communication band is different, detailed description thereof is omitted.

  The communication control unit 111 can perform data communication of 5 GHz and 2.4 GHz via the communication unit 120 and the communication unit 130, respectively. The communication control unit 111 performs an operation based on the communication control unit 7 in the first embodiment when performing data communication in the 5 GHz band. As described above, the communication control unit 111 can perform data communication by a general method when performing data communication of 2.4 GHz.

  In this embodiment, the communication control unit 111 records a channel used for data communication in the “used channel” column of the radio wave detection table 171 when performing data communication in the 5 GHz band. Furthermore, in this embodiment, the communication control unit 111 can perform ISM that constantly monitors radar waves in a channel during data communication. Further, the communication control unit 111 can avoid the radar wave when the radar wave is detected in the ISM. Details of the operation of the ISM and the subsequent radar wave avoidance are as described above in the Background section.

  The radio wave detection control unit 112 is based on the radio wave detection control unit 3 in the first embodiment. As an example, the radio wave detection control unit 112 searches for radar waves via the first reception unit 140 for every channel in the 5 GHz band. The radio wave detection control unit 112 records detection result information 9 representing each channel in which radio waves are detected in the “radio wave detection” column of the radio wave detection table 171.

  The channel monitoring control unit 113 is based on the channel monitoring control unit 5 in the first embodiment. In this embodiment, the channel monitoring control unit 113 records that the CAC has been completed in the “monitoring channel” column of the radio wave detection table 171 when no radar wave is detected in the monitoring channel for 1 minute. The communication control unit 111 can know that the monitoring channel is available by reading the “monitoring channel” field.

  The wired WAN / LAN control unit 160 includes a layer 2 switch (L2SW) 161, a WAN port (WAN) 162, and a LAN port (LAN) 163. The WAN port 162 and the LAN port 163 are ports for wired LAN connection. The layer 2 switch 161 is a general switching hub. In the present embodiment, the wireless LAN access point 100 is connected to the broadband modem 300 via the WAN port 162.

As described above, the first receiving unit 140, the second receiving unit 150, the communication unit 120 in the present embodiment,
The structures and contents of the communication control unit 111, the radio wave detection control unit 112, and the channel monitoring control unit 113 are the same as the corresponding units in the first embodiment except for the points described above. Omitted.

  Next, the operation of the present embodiment having the above-described configuration will be described in detail. In the present embodiment, the three operations of the radio wave detection operation controlled by the radio wave detection control unit 112, the channel monitoring operation controlled by the channel monitoring control unit 113, and the data communication operation controlled by the communication control unit 111 are simultaneously performed in parallel. Done. Hereinafter, the three operations will be described in the order described above.

  First, the radio wave detection operation will be described with reference to FIG. FIG. 4 is a flowchart showing a radio wave detection operation controlled by the radio wave detection control unit 112 in the second embodiment. In this embodiment, it is assumed that the radio wave detection control unit 112 searches for radar waves for each channel from the W53 band channel 52 to 64 channel, and then for the entire range from the W56 band channel 100 to 140 channel. .

  When the wireless LAN access point 100 is activated, the radio wave detection control unit 112 initializes the radio wave detection table 171 (step S10). Specifically, the radio wave detection control unit 112 clears “0” in each column except the “channel” column in the radio wave detection table 171 shown in FIGS. 7 and 8. 7 and 8 are diagrams illustrating an example of the radio wave detection table 171 according to the second embodiment. FIG. 7 is an example of the radio wave detection table 171 for all channels (channels 52 to 64) in the W53 band. FIG. 8 is an example of a radio wave detection table 171 for all channels (channels 100 to 140) in the W56 band.

  Next, the radio wave detection control unit 112 sets a detection target channel (step S11). Specifically, the radio wave detection control unit 112 sets 52 channels as detection target channels in the first operation. The radio wave detection control unit 112 may set the detection target channel by avoiding the channel used by the communication control unit 111 for data communication. That is, the radio wave detection control unit 112 may set 52 channels as detection target channels after confirming that the used channel column corresponding to “52” is “0”. If the used channel column of 52 channels is “1”, the radio wave detection control unit 112 determines that the 52 channels are used for data communication, and checks the next 56 channels.

  Next, the radio wave detection control unit 112 monitors the radar wave for 1 minute or until a radar wave is detected in the detection target channel (step S12). Specifically, the radio wave detection control unit 112 monitors radar waves for one minute for 52 channels via the first reception unit 140. When a radar wave is detected on the way, the radio wave detection control unit 112 may stop monitoring and proceed to the next step before one minute has passed.

  When a radar wave is detected in step S12 (YES in step S13), the radio wave detection control unit 112 records that a radio wave (radar wave) is detected in the radio wave detection table 171 (step S14). That is, the radio wave detection control unit 112 records the detection result information 9 in the first embodiment in the storage device 170 as the radio wave detection table 171. Specifically, when a radar wave is detected in 52 channels, the radio wave detection control unit 112 writes “1” in the radio wave detection column corresponding to “52” in the channel column of the radio wave detection table 171.

  After step S14 or when no radar wave is detected for one minute in step S12, the radio wave detection control unit 112 repeats the operation from step S11 on for the next detection target channel. Specifically, the radio wave detection control unit 112 sets 56 channels, which are the next channels after 52 channels, as detection target channels. For example, when the detection target channel is 64 channels, which is the last channel in the W53 band, the radio wave detection control unit 112 may set 100 channels, which is the first channel in the W56 band, as detection target channels. For example, when the detection target channel is 140 channel which is the last channel of the W56 band, the radio wave detection control unit 112 may return to the first channel of the W53 band and set 52 channels as the detection target channels.

  In this way, information included in the radio wave detection column of the radio wave detection table 171 as shown in FIGS. 7 and 8 is generated in the storage device 170. That is, the record information (detection result information 9) of the channel used by the radar in the 5 GHz band is accumulated in the radio wave detection table 171 by the radio wave detection operation. Note that the radio wave detection control unit 112 or a control unit (not shown) may initialize the radio wave detection table 171 (step S10), for example, after one day has elapsed based on a predetermined timer or the like.

  The above is the radio wave detection operation.

  Next, the channel monitoring operation will be described with reference to FIG. FIG. 5 is a flowchart showing a channel monitoring operation controlled by the channel monitoring controller 113 in the second embodiment. It is assumed that the radio wave detection column of the radio wave detection table 171 is as shown in FIGS. 7 and 8 at the time when the following operation is started. Further, it is assumed that the monitoring channel column of the radio wave detection table 171 does not change from the initialized state and is all “0”.

  First, when the wireless LAN access point 100 is activated, the channel monitoring control unit 113 sets, as a monitoring channel, one of channels (non-detection channels) in which no radio wave is detected based on the radio wave detection table 171 ( Step S20). At this time, the channel monitoring control unit 113 sets a monitoring channel by avoiding the channel used by the communication control unit 111 for data communication. Specifically, the channel monitoring control unit 113 can arbitrarily select one channel from the channels whose radio wave detection column and used channel column are “0” in FIGS. 7 and 8. Here, as an example, the channel monitoring control unit 113 sets 112 channels as monitoring channels.

  Next, the channel monitoring controller 113 monitors the radar wave for 1 minute or until a radar wave is detected in the monitoring channel (step S21). Specifically, the channel monitoring control unit 113 monitors radar waves for 1 minute with respect to the 112 channels via the second receiving unit 150. If a radar wave is detected on the way, the channel monitoring control unit 113 may stop monitoring and proceed to the next step before one minute has passed.

  In step S21, when a radar wave is not detected for 1 minute (NO in step S22), the channel monitoring control unit 113 records in the radio wave detection table 171 that the monitoring channel is available (step S23). Specifically, the channel monitoring control unit 113 writes “1” in the monitoring channel column corresponding to “112” in the channel column of the radio wave detection table 171. At this time, the 112 channels being monitored can be regarded as channels that can transmit and receive radio waves as CAC-completed channels because no radar wave is detected for one minute.

  When the radar wave is not detected, the channel monitoring control unit 113 determines whether the radar wave is detected in the monitoring channel or the communication control unit 111 uses the monitoring channel as a data communication channel. Monitoring of the monitoring channel is continued after step S23. Note that operations of the communication control unit 111 and the channel monitoring control unit 113 when the monitoring channel is used as a data communication channel will be described later in the description of the data communication operation.

  On the other hand, when a radar wave is detected in step S21 (YES in step S22), the channel monitoring controller 113 records that a radio wave (radar wave) is detected in the radio wave detection table 171 (step S30). The operation of the channel monitoring controller 113 in step S30 is the same as the operation of the radio wave detection controller 112 in step S14.

  Next, the channel monitoring controller 113 records in the radio wave detection table 171 that the monitoring channel cannot be used (step S31). Specifically, the channel monitoring control unit 113 writes “0” in the monitoring channel column corresponding to the channel (monitoring channel) in which the radar wave is detected. Thereafter, the channel monitoring control unit 113 performs the operations after step S20 on the newly selected monitoring channel.

  In this way, the channel monitoring control unit 113 constantly monitors radar waves for channels in which radar waves are not detected and are not used for data communication. In addition, it is recorded in the monitoring channel column of the radio wave detection table 171 that there is an available channel for which no radar wave is detected for 1 minute or longer.

  The above is the channel monitoring operation.

  As a final description of the operation, the data communication operation will be described with reference to FIG. FIG. 6 is a flowchart showing a data communication operation controlled by the communication control unit 111 in the second embodiment. It is assumed that the radio wave detection column and the monitoring channel column of the radio wave detection table 171 are as shown in FIGS. 7 and 8 when the following operation is started. Further, it is assumed that the used channel column of the radio wave detection table 171 is not changed from the initialized state and is all “0”.

  When the wireless LAN access point 100 starts data communication with the wireless LAN slave device 200 in the 5 GHz band, the communication control unit 111 records a data communication channel (used channel) used for data communication in the radio wave detection table 171. (Step S40). As an example, the channel used for data communication is 100 channels. That is, the communication control unit 111 writes “1” in the used channel column corresponding to “100” in the channel column of the radio wave detection table 171.

  Next, the communication control unit 111 performs data communication via the communication unit 120 in the data communication channel (used channel). The communication control unit 111 performs radar wave monitoring (ISM) in the data communication channel in parallel with the data communication (step S41). If the radar wave is not detected (NO in step S42), the communication control unit 111 continues the data communication and the ISM as it is until the data communication is completed. That is, the communication control unit 111 ends the operation when the data communication ends.

  When a radar wave is detected by ISM (YES in step S42), the communication control unit 111 stops data communication with the wireless LAN slave device 200 within 10 seconds and switches the data communication channel according to the following procedure.

  First, the communication control unit 111 records that a radio wave (radar wave) is detected in the radio wave detection table 171 (step S43). The operation of the channel monitoring controller 113 in step S43 is the same as the operation of the radio wave detection controller 112 in step S14.

  Next, the communication control unit 111 deletes the record of the channel used in the radio wave detection table 171 (step S44). Specifically, the communication control unit 111 rewrites the used channel column corresponding to 100 channels recorded in step S40 to “0”.

  Next, the communication control unit 111 checks whether there is an available monitoring channel (step S45). That is, the communication control unit 111 confirms whether or not radio waves have been detected for one minute or longer in the monitoring channel monitored by the channel monitoring control unit 113. In the present embodiment, the communication control unit 111 searches for a channel whose monitoring channel column in the radio wave detection table 171 is “1”. In the case of this specific example, the communication control unit 111 finds that the monitoring channel column of the 112 channel is “1”.

  If there is an available monitoring channel, the communication control unit 111 changes the data communication channel to a monitoring channel (step S47). Specifically, the communication control unit 111 changes the channel used for data communication to the discovered 112 channel. Note that the operation of the communication control unit 111 performed after the data communication channel is changed may be performed in parallel with the data communication.

  Next, the communication control unit 111 clears the record of the monitoring channel in the radio wave detection table 171 (step S46). Specifically, the communication control unit 111 rewrites the monitoring channel column of the 112 channel to “0”. Furthermore, the communication control unit 111 notifies the channel monitoring control unit 113 that the monitoring channel is used as a data communication channel. Receiving the notification, the channel monitoring control unit 113 restarts the operation from step S20 which is the first operation in FIG.

  In step S45, when there is no available monitoring channel (NO in step S45), the communication control unit 111 waits for completion of CAC (1 minute monitoring) executed by the channel monitoring control unit 113. That is, the communication control unit 111 stands by until any one monitoring channel column in the radio wave detection table 171 becomes “1”.

  In this way, the communication control unit 111 can immediately return to step S40 after changing the data communication channel and perform the subsequent operation (resumption of data communication). That is, since the changed data communication channel is a channel in which the radar wave has not been detected for one minute or longer by the channel monitoring control unit 113, the data communication can be resumed immediately.

In the specific example described above, the communication control unit 111 may select an available monitoring channel as a data communication channel when data communication is first started (step S40).
That is, the communication control unit 111 may perform the same operations as those in steps S45 to S47 when newly starting data communication. As a result, the communication control unit 111 can immediately start data communication even when newly starting data communication.

  The above is the data communication operation.

  As described above, in the present embodiment, similarly to the first embodiment described above, it is possible to suppress the wireless communication interruption (standby) time in a communication band in which priority radio waves such as radar waves are present. There is an effect. Further, similarly to the first embodiment, even when a new wireless communication is started, the present embodiment has an effect that the waiting time until the start of the wireless communication can be suppressed.

  In addition, the following can be considered as a modification of this embodiment.

  For example, the radio wave detection control unit 112 and the channel monitoring control unit 113 may detect a carrier (carrier signal) transmitted by another wireless LAN communication device in addition to the radar wave. In this modification, the radio wave detection control unit 112 and the channel monitoring control unit 113 handle radar waves and carriers in the same manner. For example, the radio wave detection control unit 112 sets the carrier to be monitored, and sets the radio wave detection column of the radio wave detection table 171 to “1” even when the carrier is detected (steps S12 to S14 in FIG. 4). Further, the channel monitoring control unit 113 also monitors the carrier in step S21 in FIG. 4, and when the carrier is detected, the same operation as when the radar wave is detected (steps S30 and S31 in FIG. 5). Execute.

  In this way, the communication control unit 111 can use a monitoring channel free from radio wave interference with other wireless LAN communications in addition to the radar wave as a switching destination of the data communication channel.

  As described above, this modification has an effect of avoiding radio wave interference with other wireless LAN communications.

  This is because the radio wave detection control unit 112 and the channel monitoring control unit 113 monitor (detect) the carrier in addition to the radar wave.

  As another modification of the present embodiment, the communication control unit 111 not only waits for CAC completion by the channel monitoring control unit 113 when there is no available monitoring channel (NO in step S45 in FIG. 6). The communication control unit 111 itself may try CAC. That is, the communication control unit 111 waits for the monitoring channel column of the radio wave detection table 171 to be “1”, and performs radar for 1 minute for any one of the channels whose radio wave detection column is “0”. Waves may be monitored. The communication control unit 111 then detects whether a radar wave is detected for one minute for the channel being monitored, or one of the monitoring channel fields in the radio wave detection table 171 is “1”. The earlier one can obtain an available monitoring channel.

  In order to prevent the communication control unit 111 from attempting CAC for the same channel as the channel monitoring control unit 113, the channel monitoring control unit 113 sets the monitoring channel before one minute has elapsed from the start of monitoring as the radio wave detection table 171, etc. The communication control unit 111 may be notified via

  As described above, in this modification, when a radar wave is detected in the channel monitored by the channel monitoring control unit 113 and the CAC for the next monitoring channel is not completed, the communication control unit 111 becomes a new channel. On the other hand, there is an effect of reducing the waiting time when starting communication.

  The reason for this is that the channel monitoring control unit 113 and the communication control unit 111 try to perform CAC on two channels, so that the possibility of preparing a CAC available channel earlier is increased.

  In each embodiment described above, each unit shown in FIGS. 1 to 3 may be configured by an independent hardware circuit, or may be regarded as a function (processing) unit (software module) of a software program. it can. However, the division of each part shown in these drawings is a configuration for convenience of explanation, and various configurations can be assumed for mounting. An example of the hardware environment in such a case will be described with reference to FIG.

  FIG. 9 is a diagram illustrating a configuration of a computer (information processing apparatus) applicable to each embodiment of the present invention and a wireless communication apparatus and a wireless communication system according to a modification thereof. That is, FIG. 9 shows a configuration of a computer capable of realizing at least one of the wireless communication device 1, the wireless LAN access point 100, the wireless LAN slave device 200, and the broadband modem 300 in each of the above-described embodiments. The hardware environment which can implement | achieve each function in each embodiment is shown.

  9 includes a CPU (Central Processing Unit) 901, a ROM (Read Only Memory) 902, a RAM (Random Access Memory) 903, a communication interface (I / F) 904, a display 905, and a hard disk device (HDD). ) 906, and these are connected via a bus 907. Note that when the computer shown in FIG. 9 functions as the wireless communication device 1, the wireless LAN access point 100, the wireless LAN slave device 200, and the broadband modem 300, the display 905 need not always be provided.

  The communication interface 904 is a general communication unit that realizes communication between the computers in each of the above-described embodiments. The wireless communication device 1, the wireless LAN access point 100, the wireless LAN slave device 200, and the broadband modem 300 can have a plurality of communication interfaces 904. The hard disk device 906 stores a program group 906A and various storage information 906B. The program group 906A is, for example, a computer program for realizing a function corresponding to each block (each unit) shown in FIGS. 1 to 3 described above. The various storage information 906B is, for example, the detection result information 9 and the radio wave detection table 171 shown in FIGS. In such a hardware configuration, the CPU 901 governs the overall operation of the computer 900.

  The present invention described by taking each of the above embodiments as an example is a computer capable of realizing the functions of the block configuration diagrams (FIGS. 1 to 3) or the flowcharts (FIGS. 4 to 6) referred to in the description of the embodiments. After the program is supplied, the computer program is read out and executed by the CPU 901 of the hardware. The computer program supplied to the computer may be stored in a non-volatile storage device (storage medium) such as a readable / writable temporary storage memory 903 or a hard disk device 906.

  In the above-described case, the computer program can be supplied to each device by a method of installing in the device via various recording media such as a floppy disk (registered trademark) and CD-ROM, the Internet, etc. Currently, a general procedure can be employed, such as a method of downloading from the outside via the communication network 1000. In such a case, the present invention can be understood to be configured by a computer-readable storage medium in which the code constituting the computer program or the code is recorded.

  Note that a part or all of the above-described embodiment can be described as the following supplementary notes, but is not limited to the following supplementary notes.

(Appendix 1)
First receiving means capable of receiving radio waves;
Detection control means for searching for a predetermined radio wave via the first receiving means for each channel in a predetermined communication band, and recording detection result information representing each channel in which the predetermined radio wave is detected;
A second receiving means capable of receiving radio waves;
Based on the detection result information, select one of the non-detection channels that is a channel in which the predetermined radio wave has not been detected as a monitoring channel, Channel monitoring control means for monitoring the presence or absence of a predetermined radio wave transmitted,
A communication means capable of transmitting and receiving data;
When data communication is started for a new channel, if the radio wave is not detected for a predetermined period or longer in the monitoring channel, the data communication is started for the monitoring channel via the communication means. And a communication control means.

(Appendix 2)
When the predetermined radio wave is detected in the monitoring channel, the channel monitoring control unit selects another non-detection channel as a new monitoring channel from the detection result information, and monitors the new monitoring channel. The wireless communication device described.

(Appendix 3)
The wireless communication apparatus according to appendix 1 or 2, wherein the detection result information includes at least channel information indicating a channel and detection information indicating that the predetermined radio wave is detected for each channel information.

(Appendix 4)
The predetermined radio wave to be detected and detected by the detection unit and the predetermined radio wave transmitted to the monitoring channel monitored by the channel monitoring unit are radar waves. The wireless communication device according to one.

(Appendix 5)
The detection means performs search and detection as the predetermined radio wave including a carrier signal in wireless communication,
The wireless communication apparatus according to claim 4, wherein the channel monitoring means monitors the radio wave transmitted to the monitoring channel including a carrier signal in wireless communication.

(Appendix 6)
Search for a predetermined radio wave for each channel in a predetermined communication band via the first receiving means,
Recording detection result information representing each channel in which the predetermined radio wave is detected,
Based on the detection result information, select any one of the non-detection channels that are channels in which the predetermined radio wave is not detected as a monitoring channel,
Monitoring the presence or absence of a predetermined radio wave transmitted to the monitoring channel via the second receiving means;
When starting data communication for a new channel,
A wireless communication method for starting the data communication with respect to the monitoring channel via a communication means capable of transmitting and receiving when the radio wave has not been detected for a predetermined period or longer in the monitoring channel.

(Appendix 7)
When the predetermined radio wave is detected while monitoring the monitoring channel, another non-detection channel is selected as a new monitoring channel from the detection result information,
The wireless communication method according to appendix 6, wherein the new monitoring channel is monitored.

(Appendix 8)
The wireless communication method according to appendix 6 or 7, wherein the detection result information includes at least channel information indicating a channel and detection information indicating that the predetermined radio wave is detected for each channel information.

(Appendix 9)
The predetermined radio wave to be searched, the predetermined radio wave to be detected in each channel recorded as detection result information, and the predetermined radio wave to be monitored for the monitoring channel are radar waves. The wireless communication method according to any one of appendices 6 to 8.

(Appendix 10)
Further, the search is performed by including a carrier signal in wireless communication in the predetermined radio wave,
It further records detection result information representing each channel from which the carrier signal was detected,
The wireless communication method according to claim 9, further monitoring whether or not there is a carrier signal in wireless communication transmitted to the monitoring channel.

(Appendix 11)
A detection control process for searching for a predetermined radio wave for each channel in a predetermined communication band and recording detection result information representing each channel in which the predetermined radio wave is detected, via the first receiving means;
Based on the detection result information, select any one of the non-detection channels, which is a channel in which the predetermined radio wave is not detected, as a monitoring channel, and via a second receiving unit, A channel monitoring control process for monitoring the presence or absence of a predetermined radio wave to be transmitted;
When data communication is started for a new channel, if the radio wave is not detected for a predetermined period or longer in the monitoring channel, the data communication is performed with respect to the monitoring channel via a communication means capable of transmission / reception. A computer program that causes a computer to execute a communication control process that starts the process.

(Appendix 12)
In the channel monitoring control process, when the predetermined radio wave is detected in the monitoring channel, another non-detection channel is selected as a new monitoring channel from the detection result information, and the new monitoring channel is monitored. The computer program described.

(Appendix 13)
13. The computer program according to appendix 11 or 12, wherein the detection result information includes at least channel information indicating a channel and detection information indicating that the predetermined radio wave is detected for each channel information.

(Appendix 14)
In the detection process, the predetermined radio wave to be searched and detected, and the predetermined radio wave transmitted to the monitoring channel to be monitored in the channel monitoring process are radar waves. The computer program as described in any one.

(Appendix 15)
In the detection process, as the predetermined radio wave, further search and detection including a carrier signal in wireless communication,
The computer program according to claim 14, wherein, in the channel monitoring process, the radio wave transmitted to the monitoring channel is further monitored including a carrier signal in wireless communication.

DESCRIPTION OF SYMBOLS 1 Wireless communication apparatus 2,140 1st receiving part 3,112 Radio wave detection control part 4,150 2nd receiving part 5,113 Channel monitoring control part 6,120,130 Communication part 7,111 Communication control part 8,170 Storage device 9 Detection result information 100 Wireless LAN access point (wireless communication device)
121, 131 Transmission / reception circuit 122, 142, 152 5 GHz antenna 132 2.4 GHz antenna 141, 151 Reception circuit 160 Wired WAN / LAN control unit 161 Layer 2 switch (L2SW)
162 WAN port (WAN)
163 LAN port (LAN)
171 Radio wave detection table 200 Wireless LAN handset 300 Broadband modem 500 Radar 1000 Communication network 1001 Wireless network 1002 Internet

Claims (10)

First receiving means capable of receiving radio waves;
Detection control means for searching for a predetermined radio wave via the first receiving means for each channel in a predetermined communication band, and recording detection result information representing each channel in which the predetermined radio wave is detected;
A second receiving means capable of receiving radio waves;
Based on the detection result information, select one of the non-detection channels that is a channel in which the predetermined radio wave has not been detected as a monitoring channel, Channel monitoring control means for monitoring the presence or absence of a predetermined radio wave transmitted,
A communication means capable of transmitting and receiving data;
When data communication is started for a new channel, if the radio wave is not detected for a predetermined period or longer in the monitoring channel, the data communication is started for the monitoring channel via the communication means. And a communication control means. The channel monitoring control means, when the predetermined radio wave is detected in the monitoring channel, selects another non-detection channel as a new monitoring channel from the detection result information, and monitors the new monitoring channel. The wireless communication device according to 1. The wireless communication apparatus according to claim 1, wherein the detection result information includes at least channel information indicating a channel and detection information indicating that the predetermined radio wave is detected for each channel information. The predetermined radio wave transmitted to the monitoring channel monitored by the channel monitoring unit and the predetermined radio wave to be detected and detected by the detection unit is a radar wave. The wireless communication apparatus according to one. The detection means performs search and detection as the predetermined radio wave including a carrier signal in wireless communication,
The wireless communication apparatus according to claim 4, wherein the channel monitoring unit monitors the radio wave transmitted to the monitoring channel including a carrier signal in wireless communication. Search for a predetermined radio wave for each channel in a predetermined communication band via the first receiving means,
Recording detection result information representing each channel in which the predetermined radio wave is detected,
Based on the detection result information, select any one of the non-detection channels that are channels in which the predetermined radio wave is not detected as a monitoring channel,
Monitoring the presence or absence of a predetermined radio wave transmitted to the monitoring channel via the second receiving means;
When starting data communication for a new channel,
A wireless communication method for starting the data communication with respect to the monitoring channel via a communication means capable of transmitting and receiving when the radio wave has not been detected for a predetermined period or longer in the monitoring channel. When the predetermined radio wave is detected while monitoring the monitoring channel, another non-detection channel is selected as a new monitoring channel from the detection result information,
The wireless communication method according to claim 6, wherein the new monitoring channel is monitored. The wireless communication method according to claim 6, wherein the detection result information includes at least channel information indicating a channel and detection information indicating that the predetermined radio wave is detected for each channel information. A detection control process for searching for a predetermined radio wave for each channel in a predetermined communication band and recording detection result information representing each channel in which the predetermined radio wave is detected, via the first receiving means;
Based on the detection result information, select any one of the non-detection channels, which is a channel in which the predetermined radio wave is not detected, as a monitoring channel, and via a second receiving unit, A channel monitoring control process for monitoring the presence or absence of a predetermined radio wave to be transmitted;
When data communication is started for a new channel, if the radio wave is not detected for a predetermined period or longer in the monitoring channel, the data communication is performed with respect to the monitoring channel via a communication means capable of transmission / reception. A computer program that causes a computer to execute a communication control process that starts the process. In the channel monitoring control process, when the predetermined radio wave is detected in the monitoring channel, another non-detection channel is selected as a new monitoring channel from the detection result information, and the new monitoring channel is monitored. 9. The computer program according to 9.

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