JP2011234285A - Wireless access point having ad hoc communication function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relay a packet data to other wireless access point by ad hoc communication means in case abnormality of a communication state on the cable LAN side is detected.SOLUTION: In case abnormality of a communication state on the side of cable LAN 5 is detected by an abnormality detecting part 17, an ad-hoc mode communication control part 14 relays a packet data received from a wireless LAN terminal belonging to an own wireless access point 1, to other wireless access point by ad hoc communication means with no intervention of the cable LAN 5; and a packet data received from other wireless access point and addressed to the wireless LAN terminal belonging to the own wireless access point, to the wireless LAN terminal.

Description

  The present invention relates to a wireless LAN terminal connected to a wired LAN (Local Area Network) and belonging to the wireless access point, and a wireless access point that relays data between the wired LAN and the wireless LAN terminal.

  In a wireless LAN system, a wireless LAN terminal generally uses a communication method based on an infrastructure mode (hereinafter, abbreviated as an infrastructure mode) conforming to IEEE802.11 that is connected to a wired LAN via a wireless access point.

  In the case of a communication method using this infrastructure mode, even when communicating between wireless LAN terminals, data is exchanged via a wireless access point and a wired LAN, so if there is an abnormality on the wired LAN side, or traffic on the wired LAN side However, there is a drawback that communication cannot be performed or throughput is reduced.

  As a technique for improving this drawback, an ad hoc mode in which direct communication is performed between wireless LAN terminals without intervention of a wireless access point in the wireless LAN standard defined in IEEE 802.11 according to the traffic situation on the wired LAN side. There is a technology that utilizes wireless communication (for example, Patent Document 1).

  However, in the technique described in Patent Document 1, each wireless LAN terminal is compatible with both the infrastructure mode and the ad hoc mode communication method, and it is necessary to switch between both modes as appropriate. For this reason, wireless LAN terminals are limited to high-function terminals that support both infrastructure mode and ad-hoc mode communication methods, and there is a problem that there is no effect on general wireless LAN terminals that have only infrastructure mode. It was.

JP 2008-277919 A

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to perform wireless communication in an infrastructure mode with a wireless LAN terminal and perform wireless communication in an ad hoc mode with another wireless access point when an abnormality or traffic congestion occurs on the wired LAN side. It is to provide a wireless access point that can execute the above.

  In order to solve the above-mentioned problem, the first invention detects an abnormality in the communication state on the wired LAN side in a wireless access point connected to the wired LAN and relaying data between the wired LAN and a wireless LAN terminal. And an ad hoc communication means for executing wireless communication in an ad hoc mode not via the wired LAN, and the abnormality detection means detects an abnormality in the communication state on the wired LAN side. The packet data received from the wireless LAN terminal belonging to the own wireless access point is relayed to the other wireless access point by the ad hoc communication means, and the packet data received from the other wireless access point is transferred to the own wireless access point. If it belongs to the wireless LAN terminal to which it belongs, If the packet data received from another wireless access point is not addressed to the wireless LAN terminal belonging to the own wireless access point, the packet data is transferred to another wireless access point other than the packet data transmission source. It is characterized by relaying.

  Further, the second invention is the wireless access point of the first invention, wherein an IP address registration means for registering a source or destination IP address related to VoIP communication in association with an extension number, and a call related to VoIP communication. Call control means for executing control, and in a state in which the abnormality detection means detects an abnormality in the communication state on the wired LAN side, a wireless LAN terminal belonging to the own wireless access point performs VoIP communication. When packet data related to call control is received, the call control means executes call control related to VoIP communication with the wireless LAN terminal, and refers to the IP address registration means to set the extension number of the communication partner. An ad hoc communication function is provided which notifies the corresponding IP address to the wireless LAN terminal.

  Furthermore, a third invention is the wireless access point according to the second invention, wherein the abnormality detection means detects a communication state abnormality on the wired LAN side and belongs to the own wireless access point. When packet data related to call control of VoIP communication is received from a LAN terminal, packet data related to a transmission source or a transmission destination registered in the IP address registration unit is preferentially relayed.

  Further, according to a fourth aspect of the present invention, in the wireless access point according to any one of the first to third aspects, the abnormality detection unit periodically sends a keep alive command requesting a response to a predetermined device connected to the wired LAN. When a response to the keep alive command is not received from the device within a certain time, it is determined that there is an abnormality.

  According to the present invention, when an abnormality or traffic tightness occurs on the wired LAN side, even a general wireless LAN terminal having only an infrastructure mode can establish a wireless access point that can bypass and relay the wired LAN. Can be provided.

... Overall configuration diagram ... Internal block configuration diagram of wireless access point according to the present invention ... Operation flowchart of wireless access point according to the present invention

DESCRIPTION OF SYMBOLS 1 ... Wireless access point by this invention 2 ... Wireless LAN telephone terminal 3 ... Radio | wireless access range of a wireless access point 4 ... Radio wave between a wireless LAN telephone terminal and a wireless access point 5 ... Wired LAN
6 ... Gateway / Router 7 ... WAN
DESCRIPTION OF SYMBOLS 8 ... SIP server 9 ... Radio wave between wireless access points 11 ... Relay control unit 12 ... Wired LAN communication unit 13 ... Infrastructure mode communication control unit 14 ... Ad hoc Mode communication control unit 15 ... wireless communication unit 16 ... antenna 17 ... abnormality detection unit 18 ... SIP call control unit 19 ... IP address registration unit

  Hereinafter, as an embodiment of the present invention, a wireless access point that accommodates a SIP (Session Initiation Protocol) -compatible wireless LAN telephone terminal related to VoIP (Voice over IP) communication will be described as an example with reference to the drawings.

  FIG. 1 is an overall configuration diagram of the present apparatus, wherein 1 is a wireless access point (hereinafter abbreviated as “this apparatus”) according to the present invention, 2 is a wireless LAN telephone terminal, 3 is a radio wave reach range of the wireless access point 1, 4 Is a wireless radio wave between the wireless LAN telephone terminal 2 and the wireless access point 1, 5 is a wired LAN, 6 is a gateway / router, 7 is a WAN (Wide Area Network), 8 is a SIP server, 9 is a wireless access with the wireless access point 1a. It is a radio wave between points 1b.

  The apparatus 1a accommodates a wireless LAN telephone terminal 2a and is connected to a wired LAN 5. Similarly, the apparatus 1b accommodates a wireless LAN telephone terminal 2b and is connected to the wired LAN 5. Here, the wireless communication using the wireless radio wave 4 complies with a wireless communication standard based on an infrastructure mode in which a wireless access point is interposed among wireless LAN standards defined by, for example, IEEE 802.11.

  For example, when making a call from the wireless LAN telephone terminal 2a to the wireless LAN telephone terminal 2b, or making a call to the WAN side via the gateway / router 6, the present apparatus 1a is connected to the wireless LAN via the radio wave 4a and the wired LAN 5. The device 1b relays call control data between the telephone terminal 2a and the SIP server 8, and the apparatus 1b transmits call control data between the wireless LAN telephone terminal 2b and the SIP server 8 via the wireless radio wave 4b and the wired LAN 5. Relay. When SIP call control is established and a call is in progress, the apparatus 1a and the apparatus 1b transmit voice data between the wireless LAN telephone terminal 2a and the wireless LAN telephone terminal 2b or the WAN 7 via the wired LAN 5 to the RTP ( Relay to each other with a Real-time Transport Protocol) packet.

  In other words, the present apparatus 1 is a wireless LAN telephone that uses a wireless communication in an infrastructure mode as a general wireless access point as a general wireless access point in a normal state where an abnormality or a situation in which the throughput is extremely reduced does not occur on the wired LAN 5 side. Data is relayed between the terminal 2 and the wired LAN 5.

  However, LAN control that monitors and controls the communication status of the entire LAN, such as when there is an abnormality or traffic congestion on the wired LAN 5 side, or when communication via the wired LAN 5 cannot be performed or the throughput is extremely reduced. When there is an instruction to bypass the wired LAN 5 from a device (not shown), the device 1 stops data relay via the wired LAN 5.

  And this apparatus 1a and this apparatus 1b relay the data from each wireless LAN telephone terminal 2 mutually by the radio | wireless communication by the radio wave 9 directly. Here, the wireless communication using the wireless radio wave 9 conforms to a wireless communication standard based on an ad hoc mode in which direct communication is performed between wireless LAN terminals without the intervention of a wireless access point, for example, among wireless LAN standards defined by IEEE 802.11. ing.

  In addition, this apparatus 1a and this apparatus 1b have an IP address, exist in each other's radio wave reachable range 3, and when communicating with each other, an ad hoc mode in which a destination is directly specified by an IP address It operates as a wireless LAN terminal that performs wireless communication according to.

  FIG. 2 is an internal block configuration diagram of the apparatus 1, in which 11 is a relay control unit, 12 is a wired LAN communication unit, 13 is an infrastructure mode communication control unit, 14 is an ad hoc mode communication control unit, and 15 is a wireless communication unit. , 16 is an antenna, 17 is an abnormality detection unit, 18 is a SIP call control unit, and 19 is an IP address registration unit.

  The relay control unit 11 exchanges data with the wired LAN 5 via the wired LAN communication unit 12, and selects either the infrastructure mode communication control unit 13 or the ad hoc mode communication control unit 14 to transmit the data to the wireless communication unit 15 and the data. Give and receive. Then, data exchanged between the wired LAN communication unit 12 and the wireless communication unit 15 is relayed to each other.

  The infrastructure mode communication control unit 13 is a control unit that causes the wireless communication unit 15 to perform communication in the infrastructure mode with the wireless LAN telephone terminal 2, and communication in the infrastructure mode is normally operating.

  The ad hoc mode communication control unit 14 is a control unit that causes the radio communication unit 15 to perform communication in an ad hoc mode with another wireless access point, and is activated by the relay control unit 11 when an abnormality occurs on the wired LAN 5 side. Is done.

  The wireless communication unit 15 is a wireless communication unit using the infrastructure mode or the ad hoc mode, and converts the data from the relay control unit 11 into a wireless signal and transmits it via the infrastructure mode communication control unit 13 or the ad hoc mode communication control unit 14. The received radio signal is restored to the original data and sent to the relay control unit 11.

  The abnormality detection unit 17 is means for monitoring an abnormality on the wired LAN 5 side and notifying the relay control unit 11 of an abnormality when an abnormality is detected. The specific means for the abnormality detection unit 17 to monitor the abnormality on the wired LAN 5 side, for example, periodically transmits a keep alive command requesting a response to the SIP server 8 connected to the wired LAN 5, and transmits it from the SIP server 8. The reception of the response signal to the kept alive command is monitored, and it is monitored whether the response signal is received within a predetermined time. If no response signal is received within a certain time, it may be determined that an abnormality has occurred in the SIP server 8 or the wired LAN 5.

  The SIP call control unit 18 is means for executing call control according to the SIP protocol with the wireless LAN telephone terminal 2, operates when the ad hoc mode is activated, and performs processing to be executed by the SIP server 8. Act on behalf.

  The IP address registration unit 19 is a means for registering the IP address of the apparatus 1 and the IP address of the communication partner, and the registered IP address is stored between the SIP call control unit 18 and the wireless LAN telephone terminal 2. This is necessary when executing call control according to the SIP protocol. Specifically, as with the SIP server 8, when the extension number is converted into an IP address and the IP address corresponding to the extension number of the communication partner is notified to the wireless LAN telephone terminal 2, the SIP call control unit 18 The IP address registration unit 19 is referred to.

  In addition, the IP address registration unit 19 may not be able to communicate via the wired LAN 5, or may experience a situation in which the throughput is extremely reduced. The wireless communication in the ad hoc mode using the radio wave 9 having a narrower band than the wired LAN 5 is used. When relaying packet data by communication, it is also means for registering the IP address of the transmission source or transmission destination of the packet data to be relayed with priority. That is, when the transmission source or transmission destination of the received packet data is registered as a transmission source or transmission destination that should be prioritized in the IP address registration unit 19, the relay processing unit 11 relays the packet data with priority. .

  In the case where priority information (bits or flags) indicating that the IP address registration unit 19 does not give priority to all the IP addresses and that the source or destination to be given priority is registered, You may make it relay in priority.

  FIG. 3 is an operation flowchart of the apparatus 1. Hereinafter, the operation of the present apparatus 1 will be described in detail using a flowchart.

  First, an operation flow of the apparatus 1 in a normal state in which communication via the wired LAN 5 cannot be performed or a situation in which the throughput is extremely reduced has not occurred will be described.

  This flow starts with the power turned on (S300). The relay control unit 11 activates the wireless communication in the infrastructure mode when the power is turned on, and whether or not the abnormality detection unit 17 has detected an abnormality on the LAN side, or shifts to the ad hoc mode from the LAN control device or the like. If there is no abnormality on the LAN side (S310, NO), or if no command for instructing the transition to the ad hoc mode is received (S311, NO), YES in S320, S321 The process proceeds to S340 via NO in S322, NO in S322, and NO in S323 and S330.

  Then, in order to execute normal data relay via the wired LAN 5, reception of packet data from the wireless LAN telephone terminal 2 and the wired LAN 5 belonging to the apparatus 1 is monitored (S340, S350).

  If packet data is received from the wireless LAN telephone terminal 2 by wireless communication in the infrastructure mode (S340, YES), the process skips S341 to the NO side and proceeds to S342, relays the received data to the wired LAN 5 (S342), and S310. Return to. In S342, the received data can be returned and relayed between the other wireless LAN telephone terminals 2 belonging to the device 1, but is not shown in the figure because it is not the main point of the present invention.

  When packet data is received from the wired LAN 5 (S350, YES) and the received data is addressed to the wireless LAN telephone terminal 2 belonging to the apparatus 1 (S351, YES), the received packet data is determined by the infrastructure mode. Relay to the wireless LAN telephone terminal 2 by wireless communication (S352), and return to S310. If NO in S350, do nothing and return to S310.

  Next, an operation flow of the apparatus 1 in a state where an abnormal situation in which communication via the wired LAN 5 cannot be performed or the throughput is extremely reduced will be described.

  When the abnormality detection unit 17 detects an abnormality on the LAN side (S310, YES) or when a command instructing the transition to the ad hoc mode is received from a LAN control device or the like (S311, YES), the relay control unit 11 The relay of the packet data via the LAN 5 is stopped, and the ad hoc mode communication control unit 14 that controls the wireless communication in the ad hoc mode is activated (S312).

  When wireless communication in the ad hoc mode is activated, the wireless communication unit 15 performs wireless communication in the ad hoc mode with other wireless access points while continuing wireless communication in the infrastructure mode with the wireless LAN telephone terminal 2. Execute.

  While the abnormal state continues (S320, NO), whether or not packet data is received by wireless communication in the ad hoc mode from another wireless access point (S330), wireless communication in the infrastructure mode from the wireless LAN telephone terminal 2 Whether or not packet data has been received (S340), packet data has not been received from another wireless access point (S330, NO), and packet data has not been received from the wireless LAN telephone terminal 2 (S340, NO), the process returns to NO in S350, and returns to S310 without doing anything.

  When packet data is received from another wireless access point by wireless communication in the ad hoc mode (S330, YES), it is determined whether the received packet data is priority data or not (S331, NO). Is rejected (S332), and the process returns to S310.

  Here, whether or not the data is priority data is determined based on whether or not the transmission source or transmission destination of the packet data is a destination registered in the IP address registration unit 19. In S332, when relaying is rejected, a reason for refusal may be added to notify the transmission source of the packet data that relaying is impossible.

  If the received packet data is priority data (S331, YES), it is determined whether or not the data is addressed to the wireless LAN telephone terminal 2 belonging to the apparatus 1 (S333), and the wireless LAN telephone belonging to the apparatus 1 is determined. If it is not addressed to the terminal 2 (S333, NO), the data is directly relayed to another wireless access point by wireless communication in the ad hoc mode (S334), and the process returns to S310. By the data relay in S334, communication between remote wireless LAN telephone terminals 2 via a plurality of the apparatuses 1 becomes possible.

  If it is addressed to the wireless LAN telephone terminal 2 belonging to the present apparatus 1 (S333, YES), it is determined whether or not the received packet data is data (for example, Invite) related to SIP call control, and SIP call control is performed. If the data is not relevant (S335, NO), the process proceeds to S337. If the data is related to SIP call control (S335, YES), the process related to SIP call control is executed (S336), and the process proceeds to S337.

  Here, in the process related to SIP call control (S336), the extension numbers of the caller and callee are converted into IP addresses, and the converted IP address is used as the IP address of the communication partner as the caller and callee. Both sides are notified. Then, the source and destination wireless LAN terminals 2 communicate the call voice data with each other by using the RTP packet between the two terminals using the notified IP address of the communication partner. Note that other processes related to SIP call control are not the main points of the present invention, and thus detailed description thereof is omitted.

  In S337, the SIP response message processed in S336 (for example, 200 OK) or the received packet data not related to the SIP call control (for example, RTP packet of voice data) for the received SIP call control data (also referred to as a message). Then, it relays to the wireless LAN telephone terminal 2 belonging to the apparatus 1 and returns to S310.

  When the ad hoc mode is activated and packet data is received from the wireless LAN telephone terminal 2 by wireless communication in the infrastructure mode (S340, YES), S341 is returned to the YES side and the process proceeds to S343. It is determined whether the received packet data is priority data (S343). If it is not priority data (S343, NO), the relay is rejected (S344), and the process returns to S310.

  Here, the contents of the determination of whether or not the data is priority data (S343) and the relay rejection (S344) are the same as the contents described in S331 and S332, and the description will not be repeated.

  If the received packet data is priority data (S343, YES) and is not data related to SIP call control (S345, NO), the process proceeds to S347 as it is and is data related to SIP call control (for example, Invite) (S345). , YES), processing related to SIP call control is executed, a SIP response message is generated (S346), and the process proceeds to S347.

  In S347, the SIP response message generated by processing in S346 (for example, 200 OK) or the received packet data (for example, the RTP voice packet of the voice data), and other radio waves within the radio wave reachable range 3 of the apparatus 1 The data is relayed to the wireless access point (for example, the present apparatus 1b for the present apparatus 1a) by the wireless communication in the ad hoc mode, and the process returns to S310.

  As described above, between the predetermined wireless LAN telephone terminal 2 belonging to another wireless access point and the wireless LAN telephone terminal 2 belonging to the present apparatus 1 by the flow of S330 to S337 and S340 to S347. Are relayed to each other without using the wired LAN 5.

  As a result, even if an abnormality or traffic congestion occurs on the wired LAN side, wireless communication between the wireless access points (this device 1) using the ad hoc mode is utilized, and wireless LAN terminals belonging to this device 1 are connected to each other. Calls and calls can be made.

  Note that the SIP call control processing in S336 and S346 is performed by the SIP call control unit 18 of the present apparatus 1 on behalf of the processing to be executed by the SIP server 8, and the wireless LAN telephone terminal 2 and the present apparatus in S337. Data relay with 1 remains in wireless communication in the infrastructure mode. Therefore, the wireless LAN telephone terminal 2 may be a general wireless LAN telephone terminal that does not have a wireless communication function in the ad hoc mode.

  Next, a flow for resuming communication via the wired LAN 5 from the ad hoc mode and returning to the normal infrastructure mode will be described. After starting the ad hoc mode in S312, the relay control unit 11 monitors the normality on the LAN side detected by the abnormality detection unit 17 (S320).

  Detected that the LAN side is in a normal state (S320, YES), received a command for canceling the command from the LAN control device or the like that instructed the transition to the ad hoc mode in YES of S311 and returning to the infrastructure mode In the case (S321, YES), or when the ad hoc mode is not forcibly activated (S322, NO), the ad hoc mode is stopped (S323).

  Thereby, the data relay in the infrastructure mode via the wired LAN 5 by S342 and S352 described above is resumed.

  Note that the state in which the ad hoc mode is forcibly activated in S322 is a case where the command instructed to shift to the ad hoc mode received from the LAN control device or the like in S311 is still valid.

  As described above, according to the present invention, when an abnormality or traffic congestion occurs on the wired LAN side, even a general wireless LAN terminal having only an infrastructure mode bypasses the wired LAN and performs data A wireless access point that can be relayed can be provided.

  In addition, since the registration means for the source or destination IP address required for wireless communication in the ad hoc mode can be used for preferential relay processing of packet data in the event of an abnormality, the bandwidth is narrower than usual or the throughput is lower. Wireless communication by mode can be used effectively.

  Further, in response to an instruction from the LAN control device or the like to bypass the wired LAN 5, the present apparatus 1 stops the data relay via the wired LAN 5 and switches to the relay in the ad hoc mode. In addition, communication between wireless LAN terminals is possible, which is convenient.

  In the above embodiment, the apparatus 1 has been described by taking the wireless access point that accommodates the SIP-compliant wireless LAN telephone terminal as an example, but the present invention is not limited to this. For example, the call control protocol of the wireless LAN telephone terminal may be other than SIP (for example, H323), and the wireless LAN terminal may be a general data terminal other than the telephone terminal (for example, Portable personal computers).

Claims (4)

In a wireless access point connected to a wired LAN and relaying data between the wired LAN and a wireless LAN terminal,
An abnormality detection means for detecting an abnormality in the communication state on the wired LAN side, and an ad hoc communication means for executing wireless communication in an ad hoc mode not via the wired LAN with another wireless access point,
When the abnormality detection unit detects an abnormality in the communication state on the wired LAN side,
The packet data received from the wireless LAN terminal belonging to the own wireless access point is relayed to the other wireless access point by the ad hoc communication means, and the packet data received from the other wireless access point belongs to the own wireless access point. If the packet data is addressed to the wireless LAN terminal, the packet data is relayed to the wireless LAN terminal. If the packet data received from another wireless access point is not addressed to the wireless LAN terminal belonging to the own wireless access point, the packet data A wireless access point having an ad hoc communication function, characterized in that the packet data is relayed to a wireless access point other than the transmission source. The wireless access point according to claim 1,
IP address registration means for registering an IP address of a transmission source or transmission destination related to VoIP communication in association with an extension number, and call control means for executing call control related to VoIP communication,
In a state where the abnormality detection means is detecting an abnormality in the communication state on the wired LAN side, when packet data related to call control of VoIP communication is received from a wireless LAN terminal belonging to the own wireless access point,
The call control means executes call control related to VoIP communication with the wireless LAN terminal, and refers to the IP address registration means to notify the wireless LAN terminal of an IP address corresponding to the extension number of the communication partner. A wireless access point having an ad hoc communication function. The wireless access point according to claim 2,
In a state where the abnormality detection means is detecting an abnormality in the communication state on the wired LAN side, when packet data related to call control of VoIP communication is received from a wireless LAN terminal belonging to the own wireless access point,
A wireless access point having an ad hoc communication function, wherein packet data related to a transmission source or a transmission destination registered in the IP address registration means is preferentially relayed. The wireless access point according to any one of claims 1 to 3,
The abnormality detection means periodically transmits a keep alive command requesting a response to a predetermined device connected to the wired LAN, and an abnormality occurs when a response to the keep alive command is not received from the device within a predetermined time. A wireless access point having an ad hoc communication function.

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