JP7311757B2 - Wireless relay device, wireless LAN system using the same, and wireless relay method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wireless relay device, a wireless LAN system using the same, and a wireless relay method. The present invention relates to a wireless LAN system comprising one or more wireless relay slave units wirelessly connected to a wireless relay master unit, and a large number of wired or wireless communication terminals connected to the wireless relay slave units.

In addition to the original 2.4 GHz band, the frequency used in the wireless LAN system now uses a 5 GHz band in order to avoid congestion and enable faster data transfer. . However, the 5 GHz band is already used conventionally for other applications such as weather radar.

Therefore, for example, in the IEEE 802.11a standard for wireless LAN, when using a frequency band (channel) called W53 or W56, DFS (Dynamic Frequency Selection) is used to prevent interference with other applications such as the weather radar. A control called The DFS control, when detecting the radio wave for the other use, avoids interference by shifting the channel. A CAC (Channel Availability Check), which is monitored for a predetermined period of time and determined, is also performed. Therefore, wireless LAN communication cannot be performed during these periods. Also, when the CAC is performed, if radio waves for other purposes are detected again, the work of searching for another channel will be repeated, and communication will continue to be impossible during that time.

Therefore, in Patent Document 1, a wireless LAN access point is provided with a plurality of wireless interfaces each having a different SSID. , proposes a wireless LAN access point that provides the SSID of a wireless interface that has become unusable through a multi-SSID function that can handle multiple SSIDs on a single wireless interface so that the sessions of communication terminals under its control will not be interrupted. It is

Also, instead of installing a plurality of wireless interfaces in one wireless LAN access point as described above, it is conceivable to arrange a plurality of wireless LAN access points via a switching hub.

In these cases, the wireless LAN access point and wireless communication terminal can recognize that the connection destination has changed, but the switching hub cannot detect that the connection destination of the wireless communication terminal has changed, and sends packets to the wrong port. I keep doing it. In order to address such a problem, in Patent Documents 2 and 3, when a communication terminal switches wireless LAN access points to be connected (when roaming), it broadcasts a predetermined frame so that a switching hub can be used. It describes rewriting the address table so that appropriate frames can be delivered quickly even after roaming.

Japanese Patent Application Laid-Open No. 2009-100210 JP-A-2003-152740 JP 2018-107726 A

There are various wireless LAN system configurations, and as described above, a communication terminal not only performs wireless communication with a wireless relay device such as an access point directly connected to a switching hub, but also has a wireless communication terminal connected directly to the switching hub. In some cases, the wireless relay device is used as a wireless relay parent device, and a wireless relay slave device serving as a wireless relay device is connected wirelessly or by wire. In such a case, even if the wireless relay slave unit to which the communication terminal belongs switches the connection destination to another wireless relay master unit (even if roaming), the communication terminal does not know that. Therefore, the methods of Patent Documents 2 and 3 cannot be used. There is also a wireless LAN system configured with a plurality of switching hubs to which wireless relay devices are connected.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless relay device connected to each port of a switching hub as a wireless relay base unit, and a communication terminal connected to the wireless relay base unit via the wireless relay slave unit. To provide a wireless relay device, a wireless LAN system using the same, and a wireless relay method, which enable communication of a communication terminal even when connection is switched.

A wireless relay device of the present invention includes a switching hub having a filtering function , a wireless relay base unit connected to each port of the switching hub, a wireless relay slave unit wirelessly connected to the wireless relay base unit, and the wireless A wireless repeater connected to itself according to a predetermined transition condition in a wireless relay device used as the wireless relay master device in a wireless LAN system comprising a communication terminal connected to the relay slave device. determining whether or not the connection destination should be transferred to the device, and if it is determined that the transfer is to be made, the wireless relay device is provided with pre-stored information on another wireless relay device to connect the wireless relay device. a transition condition determination unit for switching a destination; a storage unit for storing information of a communication terminal connected to the wireless repeater; a terminal calling unit that broadcasts or multicasts a signal requesting a response from the communication terminal through the switching hub based on the information of the communication terminal stored in the storage unit. .

Further, the wireless relay method of the present invention includes a switching hub having a filtering function , a wireless relay base unit connected to each port of the switching hub, a wireless relay slave unit wirelessly connected to the wireless relay base unit, In a wireless relay method in a wireless relay device used as a wireless relay master device in a wireless LAN system comprising a communication terminal connected to the wireless relay slave device, communication connected to the wireless relay slave device. a storage step of storing terminal information; and determining whether or not to transfer a connection destination to a wireless relay slave device connected to the own device according to a predetermined transition condition; a transition condition determining step for giving prestored information on another wireless relay master unit to a device to switch the connection destination of the wireless relay slave unit; and a terminal calling step of transmitting, through the switching hub , a signal requesting a response from the communication terminal based on the information of the communication terminal stored in the storing step, when switching is performed. characterized by comprising

According to the above configuration, in the wireless relay device that is connected to each port of the switching hub and serves as a wireless relay base unit and the wireless relay method thereof, for example, the frequency band (channel ) and perform DFS (Dynamic Frequency Selection) control to prevent interference with weather radar. A communication terminal connected to the radio relay master unit via the radio becomes incapable of communication during CAC (Channel Availability Check) to determine whether or not radio waves for other purposes are detected in the channel. Also, when radio waves for other purposes are detected again when CAC is performed, the work of searching for another channel is repeated, and communication becomes impossible during that time. Therefore, in the present invention, in the shift condition determination step, the shift condition determination unit determines whether or not the channel should be shifted according to a predetermined shift condition. Information is given to the wireless relay slave unit, that is, an introduction is made, and the wireless relay master unit to which the wireless relay slave unit is connected is switched (the connection destination is changed). As a result, the communication terminals under the wireless repeater can be continuously (without a break) connected to the network.

Preferably, the transition condition determination unit is a radio wave condition detection unit that determines whether or not to change the channel according to the radio wave condition.

However, as it is, in the switching hub, the port corresponding to the wireless relay master unit of the migration destination and the information of the communication terminal are not associated. On the other hand, the switching hub learns a list of communication terminals belonging to each port from the source MAC address of the packet, and has a filtering function that forwards the packet only to the required port based on the destination MAC address. If not, packets to the communication terminal cannot be transferred.

Therefore, in the present invention, information such as the IP address of the communication terminal connected to the wireless relay slave is stored in the storage unit in advance in the storage step, and the radio wave condition detection unit detects the connection of the wireless relay slave. When the destination is switched to another wireless relay master unit, in the terminal calling step, the terminal calling unit broadcasts or multicasts an ARP (Address Resolution Protocol) Probe or the like. Then, the corresponding communication terminal returns ARP Reply or the like by unicast. As a result, the source can obtain the MAC address and the like, and the switching hub can learn which port the wireless relay base unit is connected to the corresponding communication terminal.

Therefore, when a communication terminal is connected to a wireless relay master unit via a wireless relay slave unit, even when the wireless relay master unit changes channels according to the radio wave conditions, communication is possible via another wireless relay master unit. Terminal communication becomes possible (Ethernet (registered trademark) frames can be transferred).

Furthermore, the wireless relay device of the present invention includes a switching hub having a filtering function , a wireless relay base unit connected to each port of the switching hub, and a wireless relay slave unit wirelessly connected to the wireless relay base unit. and a communication terminal connected to the wireless relay slave device, in a wireless relay device used as the wireless relay master device in a wireless LAN system, wherein the wireless relay slave device switches a connection destination from its own device. a child device shift determination unit that determines that the wireless relay slave device is connected to a child device shift determination unit; a storage unit that stores information on a communication terminal connected to the wireless relay device; A terminal calling unit that broadcasts or multicasts a signal requesting a response from the communication terminal through the switching hub when it is determined that the switching has been made, based on the information of the communication terminal stored in the storage unit. and

Further, the wireless relay method of the present invention includes a switching hub having a filtering function , a wireless relay base unit connected to each port of the switching hub, a wireless relay slave unit wirelessly connected to the wireless relay base unit, A communication terminal connected to a wireless relay slave device, in a wireless relay method in a wireless relay device used as the wireless relay master device in a wireless LAN system comprising a communication terminal connected to the wireless relay slave device. a storage step for storing the information of; a child device shift determination step for determining that the wireless relay slave device has switched the connection destination from its own device; When it is determined that the switching has been made, a terminal calling step of broadcasting or multicasting a signal requesting a response from the communication terminal via the switching hub based on the information of the communication terminal stored in the storing step. and

The above-mentioned radio wave condition detection step describes the operation at the time of channel shift for DFS control due to weather radar wave detection by the radio wave condition detection unit of the radio relay base unit. In the determination step, the wireless relay slave device judges the radio wave condition and the like to determine switching of the wireless relay master device to which it is connected, and similarly suppresses communication cutoff even when shifting. can be done.

Preferably, one or more of the wireless relay slave units are wireless relay master units to which wireless connections are made.

According to the above configuration, when the DFS or the like becomes unable to use a channel in one (for example, regular) wireless relay master unit, the wireless relay slave unit immediately activates another (emergency) wireless relay unit. Can be connected to the network via the base unit.

This makes it possible to realize a redundant configuration of the wireless relay master unit.

Furthermore, in the wireless relay device of the present invention, the wireless relay slave unit and the inter-building communication unit are configured.

According to the above configuration, since the inter-building communication unit constitutes an in-house network or the like, it is effective and preferable to prevent failures in connection.

A wireless LAN system according to the present invention is characterized by using the above-described wireless relay device.

According to the above configuration, in a wireless LAN system configured by adding a switching hub, one or a plurality of wireless relay slave units, and a large number of communication terminals to the above wireless relay device as a wireless relay base unit, DFS, etc. It is possible to realize a system capable of seamlessly transferring packets to a communication terminal even when the connection destination of the wireless relay slave unit is switched due to the channel switching of the wireless relay master unit by .

As described above, the wireless relay device, the wireless LAN system and the wireless relay method using the wireless relay device of the present invention are connected to each port of a switching hub and used as a wireless relay master device. When the wireless relay slave unit switches the connection destination according to the radio wave condition, etc., the wireless terminal connected to the prestored wireless relay slave unit is called by broadcasting or multicasting ARP Probe or the like.

Therefore, when the called communication terminal responds by ARP Reply or the like, the transmission source can obtain the MAC address, etc. can be learned, and subsequent communication becomes possible.

1 is a block diagram showing the configuration of a wireless LAN system using a wireless relay base unit, which is a wireless relay device according to an embodiment of the present invention; FIG. FIG. 2 is a diagram for explaining the flow of packets when a wireless relay base unit causes a wireless relay slave unit to switch connection destinations in the wireless LAN system of FIG. 1 ; FIG. 3 is a diagram showing a communication terminal list in the switching hub and the radio relay base station in FIG. 2; FIG. 10 is a block diagram showing the configuration of a wireless LAN system using a wireless relay base unit, which is a wireless relay device according to another embodiment of the present invention; FIG. 5 is a diagram for explaining the flow of packets when a wireless relay slave device switches a connection (roaming) destination wireless relay master device in the wireless LAN system of FIG. 4 ;

(Embodiment 1)
FIG. 1 is a block diagram of a wireless LAN system 10 using a wireless relay master unit 1, which is a wireless relay device according to one embodiment of the present invention. The wireless LAN system 10 comprises the wireless relay master unit 1, the switching hub 5, the wireless relay slave unit 3, the communication terminal 4 operated by the user, and another wireless relay master unit 2. be done.

The wireless relay base units 1 and 2 are installed so that their wireless communication areas overlap each other to form a redundant configuration, and three or more units may be installed in the same area. Although omitted in FIG. 1 for simplification of the drawing, there are one or a plurality of wireless relay slave units 3 under the wireless relay base unit 1, and communication under the wireless relay slave units 3 is performed. Terminals 4 are numerous. A plurality of switching hubs 5 may intervene in a communication path, which will be described later. Of course, communication from the switching hub 5 via the wireless relay base units 1 and 2 can be performed without passing through the wireless relay slave unit 3 from other communication terminals. It is sometimes done. The wireless relay master unit 2 has the same configuration as the wireless relay master unit 1, and they are connected to the ports P2 and P1 of the switching hub 2, respectively. Also, the wireless relay slave device 3 may have the same configuration as the wireless relay master devices 1 and 2. In this case, it is possible to switch between the master device and the slave device depending on the setting.

Normally, the communication terminal 4 is connected to the network from the wireless relay slave unit 3 via the wireless relay base unit 1 and the switching hub 5, and is capable of transmitting and receiving packets. The wireless relay slave device 3 and the wireless relay master device 1 are connected by a wireless LAN such as the IEEE802.11 standard. Further, the connection between the communication terminal 4 and the wireless relay slave device 3 may be a wireless LAN connection such as the IEEE802.11 standard or a wired LAN connection. In the wireless relay master unit 1, the communication control unit 14 for controlling transmission and reception is established between the hub-side communication unit 12 on the switching hub 5 side and the slave unit-side communication unit 13 on the wireless relay slave unit 3 side. Bidirectional transmission and reception of packets is possible.

Then, the 2.4 GHz band and the 5 GHz band may be used for communication of the child device side communication unit 13, and the radio wave condition of the frequency (channel) used by the child device side communication unit 13 is a transition condition It is monitored by the radio wave condition detection unit 15, which is a determination unit. When the radio wave condition detection unit 15 detects a weather radar wave when using the W53 or W56 frequency band (channel) in the IEEE802.11a standard, the radio wave condition detection unit 15 performs DFS control to prevent interference. The channel used by the unit 13 is shifted. In the transition, CAC to determine whether weather radar waves are not detected on the transition destination channel must be performed for a predetermined time, for example, one minute, and if radar waves are detected again during CAC , the radio wave condition detection unit 15 and the handset side communication unit 13 repeat the operation of searching for another channel. Therefore, the wireless relay slave device 3, that is, the communication terminal 4 cannot communicate during that time.

Therefore, it should be noted that the radio relay base unit 1 of the present embodiment detects a radar wave, which is a predetermined transition condition, by the radio wave condition detection unit 15 in the radio wave condition detection step, which is the transition condition determination step. The connection destination of the wireless repeater slave unit 3 is switched during the grace period, for example, 10 seconds, until the communication is stopped by the DFS control. The switching is performed by giving (introducing) pre-stored information (MAC address and used channel) of the other wireless relay master unit 2 from the slave unit side communication unit 13 to the wireless relay slave unit 3, This can be realized by switching the connection destination of the relay slave unit 3 as indicated by reference numerals 31 to 32 . This allows the communication terminal 4 to connect to the network continuously (without a break).

However, in the switching hub 5 as it is, the port P2 corresponding to the wireless relay base unit 2 of the migration destination and the information of the communication terminal 4 are not associated (associated with the port P1). On the other hand, the switching hub 5 learns a list of communication terminals 4 belonging to each port from the source MAC address of the packet, stores it in a table 51 for a predetermined period of time, for example, two minutes, and based on the destination MAC address. , has a filtering function that forwards packets only to the required ports. Therefore, if the switching hub 5 is not able to learn, that is, if the communication terminal 4 is not correctly registered in the table 51, the switching hub 5 receives the packet from the communication terminal 4 or the predetermined time elapses. Until the MAC address of the communication terminal 4 is discarded from the table 51, the packet to the communication terminal 4 cannot be transferred (continuous transfer to the wrong port P1).

Therefore, in the wireless relay base unit 1 of the present embodiment, the traffic information including the IP address of the communication terminal 4 connected to the wireless relay slave unit 3 is obtained in advance from the slave unit side communication unit 13 and stored in the storage step. A storage unit 17 is provided, and the radio wave condition detection unit 15 causes the wireless relay slave unit 3 to switch the connection destination, and a predetermined appropriate time when the switching is performed and the communication of the wireless relay slave unit 3 can be resumed. A terminal calling unit 18 is provided for broadcasting an ARP Probe with the IP address of the communication terminal 4 as a target IP address from the hub side communication unit 12 in the terminal calling step after the elapse.

When the wireless relay slave device 3 is enabled to communicate with the wireless relay master device 2 indicated by reference numeral 32 , the communication terminal 4 can receive the ARP Probe sent by the wireless relay master device 1 . When the target IP address of the ARP Probe matches the IP address of the communication terminal 4, the communication terminal 4 returns ARP Reply by unicast. As a result, the switching hub 5 learns which port (P2 in this case) the wireless relay master unit (wireless relay master unit 2 in this case) is connected to which port (P2 in this case) the corresponding communication terminal 4 is connected to, and stores in the table 51 can be stored. In other words, using an IP address collision avoidance mechanism (RFC 5227) for checking whether a predetermined IP address is in use, the communication terminal 4 under the wireless relay slave device 3 that has changed the channel and the original wireless relay master device 1 and MAC address information in the table 51 of all switching hubs 5 between 1 and 1 so that packets are forwarded to the correct port P2.

Therefore, when the communication terminal 4 is connected to the wireless relay master unit 1 via the wireless relay slave unit 3, even while the wireless relay master unit 1 shifts the channel according to the radio wave condition, another wireless relay can be performed. Communication of the communication terminal 4 becomes possible via the base unit 2 (Ethernet (registered trademark) frames can be transferred). Further, the wireless LAN system 10 of the present embodiment uses the wireless relay devices serving as the wireless relay master devices 1 and 2 as described above, so that the wireless relay slave device 3 can be used when the channel of the wireless relay device is switched by DFS or the like. It is possible to realize a system capable of seamlessly transferring packets to the communication terminal 4 even when the connection destination is switched.

2 and 3, changes in the table 51 of the switching hub 5 due to switching of the connection destination of the wireless relay slave device 3 from the wireless relay master device 1 to the wireless relay master device 2 as described above will be described. . FIG. 2 shows a packet flow, and FIG. 3 shows a communication terminal list in the switching hub 5 and the radio relay master unit 1. FIG. 2, the wireless relay master device 1 is the master device 1, the wireless relay master device 2 is the master device 2, the wireless relay slave device 3 is the slave device, and the communication terminal 4 is the terminal 1. In FIG. In FIG. 2, another communication terminal (not limited to wireless communication, but may be wired connection) 4a is added as terminal X. In FIG.

As shown in FIG. 2, two wireless relay masters 1 and 2 and a terminal 4 a are connected to a switching hub 5 , and a communication terminal 4 is connected to the wireless relay master 1 via a wireless relay slave 3 . The MAC address of the wireless relay base unit 1 is 00:22:44:66:88:00, the MAC address of the communication terminal 4 is 00:11:22:33:44:55, and the IP address is 192.168. .0.10, and the MAC address of the communication terminal 4a is 00:55:44:33:22:11.

In that state, when the communication terminal 4 starts normal communication as shown in FIG. :11:22:33:44:55 are newly registered in association with the port P1, and the IP address 192.168.0.10 of the communication terminal 4 is newly registered in the wireless relay base unit 1 .

Then, communication with the communication terminal 4 becomes possible, and when the communication terminal 4a starts transferring packets to the communication terminal 4 as shown in FIG. 5, the MAC address 00:55:44:33:22:11 of the communication terminal 4a is newly additionally registered in association with the port P3, and the IP address 192. 168.0.10 continues to be registered.

After that, according to the DFS control, the wireless relay base unit 1 sends a connection destination to the wireless relay slave unit 3 as shown in FIG. 2(c). Transfer to base unit 2. However, at this time, the switching hub 5 does not know the transition, so as shown in FIG. :33:44:55 becomes obsolete, and only the MAC address 00:55:44:33:22:11 of the communication terminal 4a for port P3 in FIG. 3(b) remains as valid information. In wireless relay base unit 1, IP address 192.168.0.10 of communication terminal 4 remains.

In this state, as in FIG. 2(b), as shown in FIG. 2(d), when communication terminal 4a attempts to transfer a packet to communication terminal 4, switching hub 5 uses From the communication list shown in d), wireless relay base unit 1, ie, port P1 is used, but transfer is disabled.

However, in the switching hub 5, it is possible to communicate with the wireless relay base unit 1 as the terminal using the port P1, and after a predetermined time considering the transition (roaming) period of the wireless relay slave unit 3, As shown in 2(e), the wireless relay master device 1 broadcasts the stored IP address 192.168.0.10 of the communication terminal 4 as an ARP Probe. At this time, if the wireless relay slave device 3 can communicate with the wireless relay master device 2 indicated by reference numeral 32, the communication terminal 4 can receive the ARP Probe because it is a broadcast transmission. . As a result of the transmission from the wireless relay master unit 1, the MAC address 00:22:44:66:88:00 of the wireless relay master unit 1 at the port P1 is additionally registered in the table 51 of the switching hub 5, and the wireless relay master unit 1 is registered. 1, the IP address 192.168.0.10 of the communication terminal 4 remains.

If the ARP Probe contains the IP address 192.168.0.10 of its own device, the communication terminal 4 unicasts an ARP Reply to the wireless relay master device 1 as shown in FIG. Reply with As a result, the switching hub 5 recognizes that the communication terminal 4 is connected to the wireless relay device 2 of the port P2, and as shown in FIG. Update address 00:11:22:33:44:55 with correct information for port P2. As a result, the wireless relay master device 1 confirms that the communication terminal 4 is no longer under its control, and discards the stored IP address 192.168.0.10.

Thereafter, as shown in FIG. 2G, the communication terminal 4a becomes capable of transferring packets to the communication terminal 4. FIG. At this time, the table 51 of the switching hub 5 and the terminal list of the wireless relay master unit 1 shown in FIG. 3(g) are the same as those shown in FIG. 3(f). When the channel shift of the wireless relay master device 1 is completed and the connection destination of the wireless relay slave device 3 is returned to the wireless relay master device 1, the same operation can be performed.

In this way, the wireless LAN system 10 of the present embodiment uses the wireless relay master units 1 and 2 as described above as wireless relay devices, and uses the wireless relay master units 1 and 2 according to the DFS or the like to switch channels. Packets to the communication terminal 4 can be transferred without a break even when the connection destination of the relay slave device 3 is switched.

Since the above-described wireless LAN system 10 operates with two wireless relay base units 1 and 2, it is preferable to always distribute the load (communication terminal 4) as described above. As a result, it is possible to realize a system in which communication is not interrupted in an emergency while coping with an increase in load (communication terminal 4). In the case of this load distribution, there may be three or more radio relay base units 1 and 2. FIG. In the above description, the condition for switching the connection destination of the wireless relay slave unit 3 is the radio wave condition due to radar wave detection. How to join (unevenness) may be a condition.

Therefore, in the wireless relay master units 1 and 2 of the present embodiment, a load detection unit 16 is provided for detecting the amount of load due to the wireless relay slave unit 3 as a predetermined shift condition for determining whether or not channel shift should be performed. The load detection unit 16 constitutes another transition condition determination unit, and in the load detection step, which is another transition condition determination step, the load, for example, the number of connected wireless repeaters 3 and the amount of data (packets) If there is a large bias in the number of connections, the appropriate radio relay slave unit 3 is designated and the connection destination is switched according to the instruction from the slave unit side communication unit 13 as described above. In this way, a high transfer rate can be given to each wireless repeater 3 and communication terminal 4 by load distribution at all times.

The wireless relay devices 1 and 2 may be wireless relay devices installed indoors like wireless LAN access points, or may be wireless relay devices installed outdoors for communication between buildings. In particular, since the inter-building communication unit constitutes an in-house network, etc., it is effective to prevent failures in connection. This embodiment of learning is suitable.
(Embodiment 2)
FIG. 4 is a block diagram of a wireless LAN system 10a using a wireless relay master unit 1a, which is a wireless relay device according to another embodiment of the present invention. This wireless LAN system 10a is similar to the wireless LAN system 10 described above, but differs in the configuration of the wireless relay base units 1a and 2a. The radio relay master unit 1a is similar to the above-described radio relay master unit 1, and the corresponding parts are denoted by the same reference numerals, and the description thereof is omitted.

It should be noted that the wireless relay base unit 1a of the present embodiment is provided with a handset shift determination unit 19 and a base unit notification unit 11. FIG. Here, between the wireless relay master device 1a and the wireless relay slave device 3, the wireless relay slave device 3 transmits a connection request to the wireless relay master device 1a. It becomes possible, and if it refuses, it becomes impossible to connect. Further, in this embodiment, as described above, the wireless relay master device 1a judges the radio wave condition and introduces the connection destination to the wireless relay slave device 3. It judges the situation, and when the radio wave condition of the current connection destination falls below a certain level, it transmits a disconnection signal to cancel the connection, searches for a master unit with good conditions, and transmits a connection request. Therefore, it is possible to recognize whether or not the wireless relay base unit 1a and the wireless relay slave unit 3 are connected to each other.

Therefore, in the wireless relay master device 1a of the present embodiment, the slave device transition determination unit 19 receives the status of communication with the wireless relay slave device 3 from the slave device side communication unit 13, and in the slave device transition determination step, When it is determined that the wireless relay slave device 3 has voluntarily disconnected from itself, when a predetermined appropriate time elapses from the disconnection and the wireless relay slave device 3 can resume communication, the above-mentioned In the terminal calling step, the terminal calling unit 18 is made to broadcast ARP Probe with the IP address of the communication terminal 4 as the target IP address.

The change of the connection destination from this wireless relay slave unit 3 can be caused by, for example, placing a shield near the connected wireless relay master unit or using the same channel by a completely different communication device. Occurs when radio waves do not reach the wireless repeater. After scanning, it may connect to the same wireless relay base unit again.

By configuring in this way, when the wireless relay slave device 3 that has canceled the connection occurs, the communication terminal 4 under the wireless relay slave device 3 is called and the ARP Reply is sent back to the switching hub 5. , the relationship between the port (P2) of the new connection destination wireless relay base unit (for example, 2a) and its communication terminal 4 can be learned, and similarly, the interruption of communication can be suppressed.

Further, in this embodiment, the parent device notification section 11 is provided in relation to the child device transfer determination section 19 . In the above description, the handset migration determination unit 19 detects disconnection of the wireless relay handset 3 from its own device. . Using this function, when the child device shift determination unit 19 determines that the wireless relay slave device 3 is connected to the own device in the child device shift determination step, the master device notification unit 11 3, and broadcast-transmits a packet whose transmission source is the MAC address of the wireless relay slave device 3 from the hub-side communication unit 12 in the parent device notification step.

This is because when the wireless relay slave unit 3 voluntarily switches the wireless relay master unit to which it is connected due to the radio wave conditions (for example, 1a→2a), the disconnection signal is returned to the original signal due to the deterioration of the radio wave conditions. This is because there is a case where the wireless relay parent device (1a) is not reached and the child device transition determination unit 19 cannot detect disconnection. Therefore, the base unit notification unit 11 of the new connection destination wireless relay base unit (2a) masquerades as the connected wireless relay base unit 3, and broadcasts a packet whose transmission source is the MAC address of the wireless relay base unit 3. By doing so, it is possible to inform the surroundings that the wireless relay slave unit 3 is under the control of the own unit.

As a result, the original wireless relay master device (1a) can be made to recognize that the connection of the wireless relay slave device 3 has been canceled. After that, the original wireless relay master unit (1a) causes the terminal calling unit 18 to perform the above-described terminal calling step using the IP address of the communication terminal 4 stored in the storage unit 17, transmits ARP Probe, and performs communication. By returning the ARP Reply from the terminal 4, the switching hub 5 can be made to recognize which port (P2) the communication terminal 4 is connected to.

Here, if the wireless relay slave device 3 knows the IP address of the communication terminal 4, it is conceivable that the wireless relay slave device 3 transmits the ARP Probe. However, it only reaches the wireless repeater 3 (exchange ends there), and the switching hub 5 cannot recognize the corresponding port of the communication terminal 4 . Also, it is conceivable that the wireless repeater 3 pretends to be the communication terminal 4 and transmits a signal to the switching hub 5 that "the communication terminal 4 is connected here". has traffic information. Therefore, for example, when the wireless relay slave device 3 holds the communication information of the communication terminal 4 for 2 minutes, the communication terminal 4 immediately after the communication via the wireless relay slave device 3 is completed, the single unit to another port of the switching hub 5 , and the wireless relay slave unit 3 moves from the wireless relay master unit (1a) within the above two minutes, the wireless relay slave unit 3 holds the data of the communication terminal 4 at that time, and is actually subordinate to it. If the signal "Communication terminal 4 is connected here" is transmitted even though the communication terminal 4 is not in the network, the response from the actual communication terminal 4 will collide.

Using FIG. 5, which is similar to FIG. 2, the operation of switching the connection destination from the wireless repeater slave unit 3 will be described. When the wireless relay slave unit 3 determines that the connection destination should be switched, it transmits a disconnection signal to the wireless relay master unit (1a) as shown in FIG. 5(a). However, when it is determined to switch the connection destination, the signal from the wireless relay slave unit 3 may not reach the wireless relay master unit (1a) because the radio wave conditions are often poor.

Next, as shown in FIG. 5(b), the wireless relay slave device 3 connects to the new wireless relay master device (2a), completes the aforementioned connection processing for determining whether or not communication is possible, and establishes mutual connection. Upon recognition, the wireless relay master device (2a) masquerades as the wireless relay slave device 3 and broadcasts a packet having the MAC address of the wireless relay slave device 3 as the source. However, since this is a broadcast signal and not the information of the communication terminal 4, the information of the switching hub 5 is not updated. Further, when the connection process is completed, the wireless relay slave device 3 itself may broadcast a packet whose transmission source is the MAC address of the wireless relay slave device 3, as is usually considered, but the connection process is completed. Then, the wireless relay master unit (2a) knows that the wireless relay slave unit 3 is under its control, and has information on the wireless relay slave unit 3. Therefore, as described above, the wireless relay master unit (2a) Since the device (2a) transmits the information as it is by pretending to be the wireless relay slave device 3, the communication processing from the slave device to the master device can be eliminated.

After that, in the case of FIG. 5(a), if the disconnection signal from the wireless relay slave unit 3 has not reached the wireless relay master unit (1a), the wireless relay master unit (1a) is ) receives a broadcast signal from the wireless relay master device (2a) (a signal sent by pretending to be the wireless relay slave device 3), and the wireless relay master device (1a) determines that the wireless relay slave device 3 is the connection destination. Recognizing the change, the process of calling communication terminal 4 of FIG. 2(e) can be continued as shown in FIG. 5(c).

On the other hand, in the case of FIG. 5(a), when the disconnection signal from the wireless relay slave unit 3 has reached the wireless relay master unit (1a), the wireless relay master unit (1a) returns to the diagram after a predetermined time. As shown in 5(c), call processing of the communication terminal 4 in FIG. 2(e) is performed. It should be noted that the method for determining the switching of the connection destination of the wireless relay slave device 3 by the wireless relay master device (1a) is not limited to performing both of the above two methods, but only one of them may be performed. If both of the above two methods are carried out, the ARP Probe from the radio relay base station (1a) may be transmitted twice.

In the present specification, a connection switching technique for avoiding waiting time due to DFS and CAC due to detection of weather radar waves has been described, but the present invention is not limited to such embodiments, and the gist thereof is It can be embodied in various forms without departing from the scope. For example, the present invention can be applied to a case where the wireless relay base units 1 and 2 are installed apart from each other so as to expand the communication area, and the connection destination is switched by moving the wireless relay slave unit 3. Then, the (address) table 51 of the switching hub 5 can be rewritten.

Further, in this specification, the communication terminal 4 connected to the wireless relay slave device 3 is called by broadcasting ARP Probe, but the present invention is not limited to this. 6 (IPv6) environment, the Neighbor Solicitation message may be multicast instead of broadcasting the ARP Probe.

Further, in this specification, for the sake of convenience, the wireless relay device (1, 1a; 2, 2a) connected to the switching hub 5 side is described as a parent device, and the wireless relay device (3) connected to the communication terminal 4 is described as a child device. However, it does not necessarily have to be a system in which the parent device sets the channel and the child device scans to find the parent device to establish a connection. The connection may be performed by a so-called peer-to-peer communication in which the channels to be used by each other are set in advance (multiple channels may be set), and data is transmitted if the other party is found, and not transmitted if the other party is not found.

1, 2 Wireless relay base unit (wireless relay device)
10 wireless LAN system 12 hub side communication unit 13 handset side communication unit 14 communication control unit 15 radio wave condition detection unit 16 load detection unit 17 storage unit 18 terminal call unit 19 handset shift determination unit 3 wireless relay handset 4, 4a communication terminal 5 switching hub 51 table

Claims (8)

has a filtering function A switching hub, a wireless relay base unit connected to each port of the switching hub, a wireless relay base unit wirelessly connected to the wireless relay base unit, and a communication terminal connected to the wireless relay base unit. In a wireless relay device used as the wireless relay master unit in a wireless LAN system configured by
According to a predetermined transition condition, it is determined whether or not the connection destination should be shifted to the wireless relay slave device connected to the self device. a transition condition determination unit that provides information on a wireless relay master unit and switches the connection destination of the wireless relay slave unit;
a storage unit for storing information of a communication terminal connected to the wireless relay slave device;
When the transition condition determination unit causes the wireless relay slave device to switch the connection destination, the communication terminal based on the information of the communication terminal stored in the storage unitrequest a response froma signal thatVia the switching hub,1. A wireless relay device, comprising: a terminal calling unit that performs broadcast or multicast transmission. 2. The radio relay apparatus according to claim 1, wherein said transition condition determination unit is a radio wave condition detection unit which determines whether or not to change the channel according to radio wave conditions. has a filtering function A switching hub, a wireless relay base unit connected to each port of the switching hub, a wireless relay base unit wirelessly connected to the wireless relay base unit, and a communication terminal connected to the wireless relay base unit. In a wireless relay device used as the wireless relay master unit in a wireless LAN system configured by
a slave device shift determination unit that determines that the wireless relay slave device has switched a connection destination from its own device;
a storage unit that stores information about a communication terminal connected to the wireless relay slave device;
When the handset shift determination unit determines that the wireless relay handset has switched the connection destination, the communication terminal based on the information of the communication terminal stored in the storage unit.request a response froma signal thatVia the switching hub,1. A wireless relay device, comprising: a terminal calling unit that performs broadcast or multicast transmission. 4. The wireless relay device according to any one of claims 1 to 3, wherein one or more of the wireless relay slave devices are wireless relay master devices to which the wireless relay slave devices are wirelessly connected. 5. The radio repeater device according to claim 3, wherein said radio repeater slave unit constitutes an inter-building communication unit. A wireless LAN system using the wireless relay device according to any one of claims 1 to 5. has a filtering function A switching hub, a wireless relay base unit connected to each port of the switching hub, a wireless relay base unit wirelessly connected to the wireless relay base unit, and a communication terminal connected to the wireless relay base unit. In a wireless relay method in a wireless relay device used as the wireless relay master unit in a wireless LAN system configured by
a storage step of storing information of a communication terminal connected to the wireless repeater;
In accordance with a predetermined transition condition, it is determined whether or not the connection destination should be shifted to the wireless relay slave unit connected to the own device. a transition condition determination step of giving information on a wireless relay master device and switching a connection destination of the wireless relay slave device;
When the wireless relay slave unit is caused to switch the connection destination in the transition condition determination step, the communication terminal is based on the information of the communication terminal stored in the storage step.request a response froma signal thatVia the switching hub,and a terminal calling step for broadcast or multicast transmission. has a filtering function A switching hub, a wireless relay base unit connected to each port of the switching hub, a wireless relay base unit wirelessly connected to the wireless relay base unit, and a communication terminal connected to the wireless relay base unit. In a wireless relay method in a wireless relay device used as the wireless relay master unit in a wireless LAN system configured by
a storage step of storing information of a communication terminal connected to the wireless repeater;
a slave device shift determination step for determining that the wireless relay slave device has switched a connection destination from its own device;
When it is determined in the handset shift determination step that the wireless relay handset has switched the connection destination, the communication terminal is determined based on the information of the communication terminal stored in the storage step.request a response froma signal thatVia the switching hub,and a step of calling a terminal for broadcast or multicast transmission.

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