JP2007006069A - Access point - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an access point 20 capable of quickly starting communication based on wireless LAN using an appropriate wireless channel. <P>SOLUTION: The access point 20 makes a first relay 24 perform wireless communication using a wireless channel that is not used if operating a first relay 24 having a function that relays the communication data which are transmitted/received by way of a cable LAN11 by wireless communication. It measures reception quality of beacon transmitted to each wireless channel and uses the wireless channel on which a beacon of predetermined reception quality or higher is transmitted to make a second relay 21 perform wireless communication, if it operates the second relay 21 that relays communication frames that are transmitted/received by a wireless LAN terminal 12 or other access point 20 to other wireless LAN terminal 12 and other access points by wireless communication. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an access point that performs communication based on a wireless LAN standard.

  There are known access points used in wireless LAN systems based on standards such as IEEE802.11a and IEEE802.11b. An access point having a function of relaying between a wireless LAN and a wired LAN is configured so that communication with a wireless LAN terminal under its control does not collide with communication with a wireless LAN terminal under the control of another access point. It is preferable to use a radio channel different from the access point. Conventionally, when installing an access point, a radio channel different from the radio channel used by another access point is manually set. However, when the number of access points increases, setting of access points may take time.

  In order to avoid this, Patent Literature 1 discloses that one of a plurality of access points connected to a wired LAN serves as a master access point, and the master access point is connected to the wired LAN via the wired LAN. In addition, a technique for appropriately setting wireless channels of a plurality of access points connected to a wired LAN by instructing predetermined processing to other access points is disclosed.

JP 2004-96148 A

  However, in the technique described in Patent Document 1, the wireless LAN system is not connected to a wired LAN and includes an access point that only relays communication data by wireless communication between devices in the wireless LAN. Not considered. Since such an access point is not connected to a wired LAN, the method described in Patent Document 1 cannot automatically set the wireless channel of each access point.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to enable an appropriate radio channel to be quickly set in a plurality of installed access points.

  In order to solve the above-described problem, an access point according to the present invention transmits communication data transmitted / received by another communication device connected to a wired LAN to a wireless LAN terminal or another access point by wireless communication based on the wireless LAN. A first function having a relay function and a function of relaying communication data transmitted / received by a wireless LAN terminal or another access point to another wireless LAN terminal or another access point by wireless communication based on the wireless LAN. When the relay means is operated, the first relay means performs wireless communication using an unused radio channel, and is transmitted / received by a wireless LAN terminal or other access point by wireless communication based on the wireless LAN. Communication data to other wireless LAN terminals or other access points When operating the second relay means having the function to perform the measurement, the reception quality of the beacon transmitted to each wireless channel is measured, and the wireless channel in which a beacon equal to or higher than the predetermined reception quality is transmitted is used. Thus, the second relay means performs wireless communication.

  For example, the present invention is based on a wireless LAN and a function for relaying communication data transmitted and received by other communication devices connected to a wired LAN to a wireless LAN terminal or other access point by wireless communication based on the wireless LAN. A first relay unit having a function of relaying communication data transmitted / received by a wireless LAN terminal or another access point to another wireless LAN terminal or another access point by wireless communication; and based on the wireless LAN An access point comprising second relay means having a function of relaying communication data transmitted and received by a wireless LAN terminal or other access point by wireless communication to another wireless LAN terminal or further another access point, Based on a predetermined condition, the first relay means and the second relay means A relay mode determining unit that determines which one of the relay units is to be operated, and when the relay mode determining unit determines to operate the first relay unit, by performing a channel search, an unused radio channel is determined. When the first channel allocating means for detecting and using the detected wireless channel to cause the first relay means to perform wireless communication and the relay mode determining means determine to operate the second relay means, A second channel that measures the reception quality of a beacon transmitted to a wireless channel and causes the second relay means to perform wireless communication using a wireless channel in which a beacon equal to or higher than a predetermined reception quality is transmitted An access point comprising an assigning unit is provided.

  According to the present invention, a plurality of installed access points can quickly start communication based on a wireless LAN using an appropriate wireless channel.

  Embodiments of the present invention will be described below.

  FIG. 1 is a system configuration diagram showing an example of a configuration of a wireless LAN system 10 according to an embodiment of the present invention. The wireless LAN system 10 includes a plurality of wireless LAN terminals 12 and a plurality of access points 20.

  Each of the plurality of wireless LAN terminals 12 performs wireless communication with the nearest access point 20 based on a wireless LAN standard such as IEEE802.11a or IEEE802.11b. Communication is performed with the wireless LAN terminal 12 and other communication devices 13 connected to the wired LAN 11.

  When each access point 20 is connected to the wired LAN 11, a function of relaying a communication frame transmitted / received by the communication device 13 to the wireless LAN terminal 12 or another access point 20 by wireless communication based on the wireless LAN; And a first function of relaying a communication frame transmitted / received by the wireless LAN terminal 12 or another access point 20 to another wireless LAN terminal 12 or another access point 20 by wireless communication based on the wireless LAN. Operates in relay mode.

  On the other hand, when each access point 20 is not connected to the wired LAN 11, a communication frame transmitted / received by the wireless LAN terminal 12 or another access point 20 is transmitted to another wireless LAN by wireless communication based on the wireless LAN. It operates in the second relay mode having a function of relaying to the terminal 12 or still another access point 20.

  When operating in the first relay mode, each access point 20 searches for a wireless channel used for the wireless LAN after activation, detects a free channel, and uses the detected free channel to establish a wireless LAN terminal. 12 and other access points 20 are wirelessly communicated.

In the example shown in FIG. 1, the access point 20-1 and the access point 20-2 operate as the first relay mode. The access point 20-1 determines whether it is connected to the wired LAN 11 after activation. Then, the access point 20-1 determines that it is connected to the wired LAN 11, and performs a channel search to detect an empty channel. Then, the access point 201 uses the radio channel _{f 1} detected as idle channel performs wireless LAN terminal 121 and the wireless communication.

Similarly the access point 20-2, determined to be connected to a wired LAN11 after startup, to detect a free channel, by using the radio channel f ₂ is detected idle channel, the wireless LAN terminal 12-3 and the radio Communicate. Each access point 20 waits for a random time after activation, thereby detecting the same free channel and preventing wireless communication using the same wireless channel.

  When operating in the second relay mode, each access point 20 transmits a communication frame transmitted / received by the wireless LAN terminal 12 or another access point 20 to another wireless LAN terminal 12 or another access by wireless communication. Relay to point 20.

  Further, when operating in the second relay mode, each access point 20 measures the reception quality of a beacon transmitted on each wireless channel after activation. The access point 20 performs wireless communication with the wireless LAN terminal 12 and other access points 20 using a wireless channel in which a beacon having a predetermined reception quality or higher is transmitted. Here, the predetermined reception quality of a beacon means reception quality sufficient for performing communication, for example. When measuring the received electric field strength of a beacon as the received quality of the beacon, the predetermined received quality of the beacon is, for example, −80 dBm.

In the example shown in FIG. 1, the access points 20-3, 20-4, and 20-5 are operating in the second relay mode. The access point 20-3 determines whether it is connected to the wired LAN 11 after activation. Then, the access point 20-3 determines that the access point 20-3 is not connected to the wired LAN 11, and measures the reception quality of the beacon transmitted in each wireless channel. Then, the access point 20-3, using the same radio channel _{f 1} and the radio channel _{f 1} of predetermined reception quality or more beacons are transmitted, the access point 201 and the wireless LAN terminal 12-2 And wireless communication.

Similarly to the access point 20-3, the access point 20-4 determines that it is not connected to the wired LAN 11 after activation, and measures the reception quality of the beacon transmitted in each wireless channel. Then, the access point 20-4, using the same radio channel _{f 2} and the radio channel _{f 2} that predetermined reception quality or more beacons are transmitted, the access point 20-2 and the wireless LAN terminal 12-4 And wireless communication. Similarly to the access point 20-4, the access point 20-5 determines that it is not connected to the wired LAN 11 after activation, and measures the reception quality of the beacon transmitted in each wireless channel. Then, the access point 20-5, using the same radio channel _{f 2} and the radio channel _{f 2} that predetermined reception quality or more beacons are transmitted, the access point 20-4 and the wireless LAN terminal 12-5 And wireless communication.

  FIG. 2 is a block diagram illustrating an example of a detailed configuration of the access point 20. The access point 20 includes a second relay unit 21, a second channel allocation unit 22, a first channel allocation unit 23, a first relay unit 24, a wired LAN communication determination unit 25, and a relay mode determination unit 26.

  The wired LAN communication determination unit 25 determines whether communication is possible via the wired LAN 11, for example, at the time of activation, and notifies the relay mode determination unit 26 to that effect. For example, the wired LAN communication determination unit 25 detects a connection of the communication cable by a hardware method such as a relay switch that is turned on when the communication cable is connected, and a link pulse flowing on the wired LAN 11. A method of detecting that communication is possible via the wired LAN 11 by detecting, a method of detecting that communication is possible via the wired LAN 11 when a communication frame is detected via the wired LAN 11, etc. It is used to determine whether or not communication via the wired LAN 11 is possible.

  For example, when the wired LAN communication determination unit 25 cannot detect that communication via the wired LAN 11 is possible within a predetermined period after activation, the relay mode determination unit 26 indicates that communication via the wired LAN 11 is not possible. Notify

  When the determination result received from the wired LAN communication determination unit 25 indicates that communication via the wired LAN 11 is possible, the relay mode determination unit 26 instructs the first channel allocation unit 23 to detect an empty channel. On the other hand, if the determination result of the wired LAN communication determination unit 25 is that communication via the wired LAN 11 is not possible, the relay mode determination unit 26 is transmitted to the second channel allocation unit 22 on each wireless channel. Instructs the measurement of the received quality of the beacon.

  The first channel allocation unit 23 searches for a wireless channel used for the wireless LAN and detects a free channel. Then, the first channel allocation unit 23 notifies the first relay unit 24 of the radio channel detected as an empty channel.

  The first relay unit 24 transmits a communication frame transmitted / received by another communication device 13 connected to the wired LAN 11 by wireless communication using an empty channel notified from the first channel allocation unit 23 or the wireless LAN terminal 12 or Relay to another access point 20. In addition, the first relay unit 24 transmits a communication frame transmitted / received by the wireless LAN terminal 12 or another access point 20 to another wireless LAN by wireless communication using the empty channel notified from the first channel assignment unit 23. Relay to terminal 12 or another access point 20.

  The first relay unit 24 has a MAC address learning function, and uses an address table 30 as shown in FIG. 3 to determine a communication port to which the received communication frame is transferred, and to determine the received communication frame. To the communication port.

  The process of using the address table 30 by the first relay unit 24 will be described in more detail. When the first relay unit 24 receives a communication frame, the first relay unit 24 transfers the type of the port that has received the communication frame to the address table 30. Store in the destination port 32. Then, the first relay unit 24 stores the transmission source MAC address of the communication frame in the destination MAC address 31 of the address table 30. Further, the first relay unit 24 refers to the header of the communication frame (MAC frame), and whether the communication frame is directly transmitted from the wireless LAN terminal 12 or via another access point 20. Determine if it was sent.

  Here, the header of the MAC frame used in the wireless LAN includes the MAC address of the access point 20 that relayed the frame body immediately before, in addition to the destination of the frame body and the MAC address of the transmission source communication device. The first relay unit 24 determines whether the MAC address of the access point 20 relayed immediately before is included in the header of the MAC frame, so that the communication frame is directly transmitted from the wireless LAN terminal 12. It is determined whether the data is transmitted or transmitted via another access point 20.

  Then, when directly transmitted from the wireless LAN terminal 12, the first relay unit 24 stores the fact that it is directly transmitted to the transfer destination 33, and when transmitted via the other access point 20, In the transfer destination 33, the MAC address of the other access point 20 that has passed through last is stored. In this way, each time the first relay unit 24 receives a communication frame, the first relay unit 24 adds a set of the destination MAC address 31, the transfer destination port 32, and the transfer destination 33 to the address table 30.

  As a result, when the first relay unit 24 receives a communication frame via a wireless LAN port or a wired LAN port, the first relay unit 24 receives the communication frame based on the destination MAC address of the received communication frame by referring to the address table 30. It is possible to determine where to transfer the transmitted communication frame. Therefore, the access point 20 can reduce the opportunity to transmit a broadcast frame to transfer a communication frame, and can suppress an increase in traffic on the wired LAN and the wireless LAN.

  The second channel allocation unit 22 measures the reception quality of the beacon transmitted on each radio channel. Then, the second channel allocation unit 22 notifies the second relay unit 21 of the radio channel on which a beacon having a predetermined reception quality or higher is transmitted. When there are a plurality of radio channels that transmit beacons of a predetermined reception quality or higher, the second relay unit 21 is notified of the radio channel with the best reception quality.

  In this example, the 2nd channel allocation part 22 measures the reception electric field strength of the beacon currently transmitted in each radio channel as reception quality of a beacon. As another example, the second channel allocation unit 22 may measure the frame error rate of a beacon transmitted on each wireless channel as the reception quality of the beacon.

  The second relay unit 21 transmits a communication frame transmitted / received by the wireless LAN terminal 12 or another access point 20 using the wireless channel notified from the second channel assignment unit 22 to another wireless LAN terminal by wireless communication. 12 or even another access point 20.

  The second relay unit 21 has a MAC address learning function, uses the address table 40 shown in FIG. 4 to determine the transfer destination of the communication frame received via the wireless LAN port, and receives the received communication. The frame is transmitted to the determined transfer destination. In the address table 40, a destination MAC address 41 is stored in association with the transfer destination 42.

  FIG. 5 is a flowchart showing an example of the operation of the access point 20. At a predetermined timing such as when the power is turned on, the access point 20 starts the processing shown in this flowchart.

  First, the wired LAN communication determination unit 25 determines whether communication is possible via the wired LAN 11 (S100). When communication via the wired LAN 11 is possible (S100: Yes), the relay mode determination unit 26 waits for a predetermined time (S101), and instructs the first channel allocation unit 23 to detect a free channel.

  The time for which the relay mode determination unit 26 waits in step 101 is set at random, for example. It is preferable that the standby time set here is a different value for each access point 20. This prevents the plurality of access points 20 from recognizing the same wireless channel as an empty channel even when the plurality of access points 20 connected to the wired LAN 11 are simultaneously turned on. it can.

  Next, the first channel allocation unit 23 searches for a wireless channel used for the wireless LAN (S102), and determines whether or not an empty channel has been detected (S103). When an empty channel cannot be detected (S103: No), the wired LAN communication determination unit 25 performs the process shown in step 100 again. When an empty channel can be detected (S103: Yes), the first channel allocation unit 23 notifies the first relay unit 24 of the wireless channel detected as an empty channel.

  And the 1st relay part 24 is a wireless LAN terminal by the radio | wireless communication using the empty channel notified from the 1st channel allocation part 23 for the communication frame transmitted / received by the other communication apparatus 13 connected to wired LAN11. 12 or other access points 20 and other communication frames transmitted / received by the wireless LAN terminal 12 or other access points 20 by other wireless communication using the empty channel notified from the first channel allocating unit 23. To the other wireless LAN terminal 12 or another access point 20 (S104).

  When the access point 20 is powered off (S105: Yes), the access point 20 ends the processing shown in this flowchart. When the power of the access point 20 is not turned off (S105: No), the first relay unit 24 performs the process shown in Step 104 again.

  In step 100, when communication via the wired LAN 11 is not possible (S100: No), the relay mode determination unit 26 measures the reception quality of the beacon transmitted in each wireless channel, and the second channel allocation unit 22 To instruct. And the 2nd channel allocation part 22 measures the reception quality of the beacon currently transmitted to each radio channel (S106).

  Next, the second channel allocating unit 22 determines whether or not a radio channel transmitting a beacon of a predetermined reception quality or higher has been detected (S107). When a radio channel transmitting a beacon of a predetermined reception quality or higher can be detected (S107: Yes), the second channel allocating unit 22 sets the radio channel transmitting the beacon to the second relay unit 21. Notify The second relay unit 21 transmits a communication frame transmitted / received by the wireless LAN terminal 12 or another access point 20 using the wireless channel notified from the second channel assignment unit 22 to another wireless LAN terminal by wireless communication. 12 or further to another access point 20 (S108).

  When the access point 20 is powered off (S109: Yes), the access point 20 ends the processing shown in this flowchart. When the power of the access point 20 is not turned off (S109: No), the second relay unit 21 performs the process shown in step 108 again.

  The embodiment of the present invention has been described above.

  As is clear from the above description, according to the access point 20 of the present embodiment, communication based on the wireless LAN can be quickly started in an appropriate operation mode after installation.

  In addition, this invention is not limited to said embodiment, Many deformation | transformation are possible within the range of the summary.

  For example, in the present embodiment, the second channel allocating unit 22 detects a predetermined radio channel at the time of activation and causes the second relay unit 21 to use it, but as another example, after detecting the predetermined radio channel at the time of activation In addition, for example, the reception quality of the beacon transmitted to each wireless channel at a predetermined timing such as every hour is measured, and the wireless channel in which the beacon having the better reception quality than the currently used wireless channel is transmitted. May be detected, the detected radio channel may be used by the second relay unit 21.

  Thereby, when the access point 20 connected to the wired LAN 11 is newly introduced, the reception quality of the beacon from the newly introduced access point 20 is the same as that of the beacon from the access point 20 to which it currently belongs. When the reception quality is better, the second relay unit 21 can automatically change the affiliation to the access point 20 with the better beacon reception quality.

  In this example, the access point 20 performs wireless communication with the wireless LAN terminal 12 or another access point 20 using one wireless channel. As another example, the access point 20 includes a plurality of wireless channels. May be used to perform wireless communication with the wireless LAN terminal 12 or another access point 20.

  In this case, when the access point 20 can communicate via the wired LAN 11, the access point 20 performs wireless communication with the wireless LAN terminal 12 or another access point 20 using a plurality of different wireless channels that are empty channels. On the other hand, when communication via the wired LAN 11 is not possible, the access point 20 performs wireless communication with another access point 20 using a wireless channel on which a beacon having a predetermined reception quality or higher is transmitted, and an empty channel. Is used to perform wireless communication with the wireless LAN terminal 12.

1 is a system configuration diagram showing an example of a configuration of a wireless LAN system 10 according to an embodiment of the present invention. 2 is a block diagram illustrating an example of a detailed configuration of an access point 20. FIG. 3 is a diagram illustrating an example of a configuration of an address table 30. FIG. 3 is a diagram illustrating an example of a configuration of an address table 40. FIG. 4 is a flowchart showing an example of the operation of the access point 20.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Wireless LAN system, 11 ... Wired LAN, 12 ... Wireless LAN terminal, 13 ... Communication apparatus, 20 ... Access point, 21 ... 2nd relay part, 22 ... Second channel allocating unit, 23 ... first channel allocating unit, 24 ... first relay unit, 25 ... wired LAN communication determining unit, 26 ... relay mode determining unit, 30, 40 ... Address table, 31, 41 ... Destination MAC address, 32 ... Transfer destination port, 33, 42 ... Transfer destination

Claims (2)

A function of relaying communication data transmitted / received by other communication devices connected to the wired LAN to a wireless LAN terminal or other access point by wireless communication based on the wireless LAN, and wireless communication based on the wireless LAN. A first relay means having a function of relaying communication data transmitted / received by a terminal or another access point to another wireless LAN terminal or further another access point, and wireless communication based on the wireless LAN, thereby enabling wireless LAN An access point comprising second relay means having a function of relaying communication data transmitted / received by a terminal or another access point to another wireless LAN terminal or further another access point,
Relay mode determining means for determining which of the first relay means and the second relay means is to be operated based on a predetermined condition;
When the relay mode determining unit determines to operate the first relay unit, a channel search is performed to detect an unused radio channel, and the detected radio channel is used to detect the first channel. First channel assignment means for causing the relay means to perform wireless communication;
When the relay mode determining unit determines to operate the second relay unit, the reception quality of the beacon transmitted to each wireless channel is measured, and a beacon having a predetermined reception quality or higher is transmitted. An access point comprising: second channel allocating means for causing the second relay means to perform wireless communication using a wireless channel. The access point according to claim 1,
A wired LAN communication determining means for determining whether or not communication is possible via the wired LAN;
The relay mode determining means includes
When the wired LAN communication determination means determines that communication is possible via the wired LAN, it is determined to operate the first relay means;
An access point, wherein when the wired LAN communication determination means does not determine that communication is possible via a wired LAN, the access point determines to operate the second relay means.

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