JP2016019021A - Access point, information delivery method and access point control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To share, among all access points (hereafter referred to as AP) in a wireless LAN system, radio information generated by each AP, with a reduced network load.SOLUTION: Each AP in a wireless LAN system 10, when shifting to a client AP, transmits radio information (PMK and beacon information) generated by the self-AP to a server AP 31. Also, on receiving the PMK and the beacon information from a client AP (for example, client AP 33) after shifting to the server AP 31, the AP multicast transmits the received PMK to all client APs. This enables, differently from before, all APs in the wireless LAN system to share the PMK generated by each client AP without mutually casting a multicast packet. Therefore, the network load can be reduced.SELECTED DRAWING: Figure 12

Description

  The present invention relates to an access point in a wireless LAN system, an information distribution method between access points, and a control program for each access point in the wireless LAN system.

  2. Description of the Related Art Conventionally, a wireless LAN system that includes a plurality of access points and shares information related to wireless LAN communication (hereinafter referred to as “wireless information”) between these access points is known. For example, a wireless LAN that prevents a delay in processing due to re-authentication at the time of roaming by sharing a PMK (Pairwise Master Key), which is part of wireless information used at the time of IEEE 802.1x authentication, between access points. The system is known.

  Also, in the field of this type of network system, the parent access point sends its own connection control information (MAC address information of the wireless LAN client to which the own device should allow connection) to the child access point, and the child access point A network system is known in which a point stores connection control information of a parent access point as its own connection control information (see, for example, Patent Document 1).

JP 2006-60464 A

  However, in the wireless LAN system of the type that shares the wireless information among the plurality of conventional access points, the wireless information generated by the own device is thrown in multicast packets between all the access points in the system, Since information was synchronized between these access points, the load on the network was large.

  In the second embodiment of Patent Document 1, the parent access point broadcasts its own connection control information to all the child access points in the area at predetermined notification intervals. The child access point stores the connection control information of the parent access point as its own connection control information. Therefore, according to the network system described in Patent Document 1, it is possible to reduce the load on the network when the parent access point shares the information (connection control information) held by itself with the child access point. Is possible. However, in the network system described in Patent Document 1, information generated by access points (each child access point) other than the parent access point cannot be shared among all access points in the system.

  The present invention solves the above-described problems, and can share wireless information generated by each access point among all access points in the wireless LAN system, and can reduce the load on the network. An object is to provide a possible access point, an information distribution method, and an access point control program.

  The access point according to the first aspect of the present invention is an access in a wireless LAN system including a server access point that is an information aggregation side access point and a client access point that is an information provision side access point. A priority detection unit for detecting whether or not an access point having a higher priority than the own device exists in the wireless LAN system, and an access having a higher priority than the own device by the priority detection unit When it is detected that there is a point, the server transits to the client access point, and when the priority detection unit cannot detect the presence of an access point having a higher priority than its own device, A transition control unit that controls to transition to an access point, and the client access point. An information providing unit that transmits wireless information, which is information related to wireless LAN communication, generated by itself when it transits to the server access point, and after the transition to the server access point, the information Multicast information for multicast transmission of at least part of the received wireless information to all client access points in the wireless LAN system when wireless information transmitted from the providing unit is received from the client access point And a distribution unit.

  In this access point, after the own device transits to the server access point, when another access point in the wireless LAN system transits to the client access point, with respect to the client access point, It is desirable to further include a unicast information distribution unit that unicasts at least a part of the wireless information held by the own device.

  In this access point, the wireless information multicast-transmitted by the multicast information distribution unit may include a PMK.

  In this access point, when the own device is the client access point, after transmitting the wireless information to the server access point by the information providing unit, the wireless device connected to the own device every predetermined time It is desirable to transmit the PMK for the LAN slave unit to the server access point.

  In this access point, even if the wireless information transmitted by the information providing unit includes beacon information transmitted by an access point existing in a range where wireless communication can be performed with a client access point that transmits the wireless information. Good.

  In this access point, the multicast information distribution unit performs multicast transmission of the wireless information by a UDP (User Datagram Protocol) multicast packet. When the wireless information does not fit in one UDP multicast packet at the time of this multicast transmission, The wireless information is divided into a plurality of UDP multicast packets and multicast transmitted to all client access points in the wireless LAN system, and each client access point is divided by the multicast information distribution unit. When the transmitted wireless information is received, it is desirable to combine the received wireless information and store it in its own memory.

  In this access point, when the own device is the server access point, the transition control unit, when an access point having a higher priority than the own device is connected to the wireless LAN system, the priority detection unit It is desirable to detect that there is an access point having a higher priority than the own device and to control the own device to transition to the client access point.

  In this access point, when the connection of the server access point to the wireless LAN system is released, the transition control unit of each existing client access point in the wireless LAN system It is desirable to select a new server access point from these client access points based on the new detection result by the priority detection unit.

  In this access point, the priority detection unit may determine the priority of these access points based on the version of the program possessed by each access point in the wireless LAN system.

  In this access point, the priority detection unit may determine the priority of these access points based on the value of the MAC address of each access point in the wireless LAN system.

  In this access point, each access point in the wireless LAN system shares a setting value between other access points in which a part of product identification information and at least one of the program versions are the same as the own device. It is desirable to do.

  In this access point, any one of the access points that share the setting value is set as a representative device of these access points, and this representative device includes a part of the product identification information and a program version. In response to a setting value acquisition request from another access point at least one of which is the same as the own device, the setting value of the own device may be transmitted to the other access point.

  The information distribution method according to the second aspect of the present invention provides information related to wireless LAN communication from a client access point that is an access point on the information providing side to a server access point that is an access point on the information aggregation side. Is an information distribution method for aggregating radio information and delivering the aggregated radio information from the server access point to the client access point, wherein the client access point is a radio generated by itself Transmitting information to the server access point; and when the server access point receives wireless information from the client access point, at least a part of the received wireless information is connected to the own device. All client access within a wireless LAN system Those comprising a step of multicast transmission to Into.

  The access point control program according to the third aspect of the present invention includes a server access point that is an information aggregation side access point and a client access point that is an information provision side access point. Is a program for controlling each access point in the wireless LAN system, and detects whether each access point in the wireless LAN system has an access point having a higher priority than its own device in the wireless LAN system. When the priority detection unit detects that an access point with a higher priority than the own device exists by the priority detection unit, the priority detection unit makes a transition to the client access point, and the priority detection unit determines the priority from the own device. If the server cannot detect the presence of a high access point, the server A transition control unit that controls to transition to an access point, and transmits wireless information, which is information related to wireless LAN communication, generated by itself when it transitions to the client access point to the server access point After the transition to the information providing unit and the server access point, when receiving the wireless information from the client access point transmitted by the information providing unit, at least part of the received wireless information, This is to function as a multicast information distribution unit for multicast transmission to all the client access points in the wireless LAN system.

  According to the present invention, each access point in the wireless LAN system transmits the wireless information generated by the own device to the server access point when the own device transits to the client access point. When wireless information from a client access point is received after transitioning to a server access point, at least a part of the received wireless information is multicast transmitted to all client access points in the wireless LAN system did. As a result, the wireless information generated by each client access point in the wireless LAN system is aggregated in the server access point, and the server access point receives all the client access points in the wireless LAN system. Can be distributed to points by multicast transmission. Accordingly, the wireless information generated by each client access point can be shared among all access points in the wireless LAN system. In addition, unlike the conventional wireless LAN system in which wireless information is sent in multicast packets between all the access points described above, only the server / access point transmits multicast packets, thereby reducing the load on the network. it can.

1 is a schematic network configuration diagram of a wireless LAN system including an access point according to an embodiment of the present invention. FIG. 2 is a schematic electrical block diagram of an access point in FIG. 1. The state transition diagram of the said access point. The flowchart of the state transition process performed by the said access point. The flowchart of the information transmission process by the information provision part of a client access point. The flowchart of the PMK multicast transmission process by the multicast information delivery part of a server access point. The flowchart of distribution processing of PMK etc. by the unicast information delivery part of a server access point. Explanatory drawing of the aggregation process and delivery process of wireless information performed when a new client access point is added to the said wireless LAN system. Explanatory drawing of the aggregation process and delivery process of wireless information performed when a new client access point is added to the said wireless LAN system. Explanatory drawing of the aggregation process and delivery process of wireless information performed when a new client access point is added to the said wireless LAN system. Explanatory drawing of the aggregation process and delivery process of wireless information performed when a new client access point is added to the said wireless LAN system. The sequence diagram which shows the sharing process of the access point setting value performed between each access point of the said wireless LAN system. A list of commands used between access points of the wireless LAN system. The figure which shows the payload format of the packet of the priority detection command in FIG.

  Hereinafter, an access point in a wireless LAN (Local Area Network) system according to an embodiment of the present invention will be described with reference to the drawings.

A. Embodiment A-1. Network Configuration FIG. 1 is a schematic configuration diagram of a wireless LAN system including an access point according to an embodiment of the present invention. The wireless LAN system 10 includes three wireless LAN access points (hereinafter referred to as “AP”) (AP1, AP2, AP3), which are wireless LAN base units, and a wireless terminal 4 that wirelessly connects to the AP and performs wireless LAN communication. To 6 ("wireless LAN slave" in claims). APs 1 to 3 are APs having the same network segment (synonymous with “network address”) (belonging to the same subnet). In the following description, the above network segment is abbreviated as “segment”.

  In this wireless LAN system 10, firmware (corresponding to the control program 18 in FIG. 2) possessed by each AP 1-3 operates on the CPU of these APs 1-3, so that the server AP Are autonomously selected based on the server priority (the priority for selecting the server AP, which corresponds to “priority” in the claims), which will be described in detail later. The selected AP transitions to the server AP, and the other APs in the wireless LAN system 10 transition to the client / AP. For example, as shown in FIG. 1, when AP1 becomes a server AP (transitions), the other APs 2-3 become client APs (transitions). Therefore, the wireless LAN system 10 includes a server AP and a client AP.

  Here, the client AP transmits (provides) information related to wireless LAN communication generated by itself (hereinafter referred to as “wireless information”) to the server AP, and the server AP is provided by the client AP. Collects wireless information. That is, the client AP is an information providing AP, and the server AP is an information aggregating AP. The server AP distributes information such as wireless information to the client AP, and the client AP receives information such as wireless information distributed from the server AP. The server AP also has a function as a client AP.

  The network shown in FIG. 1 includes a wired LAN in which APs 1 to 3 are connected by a hub 7 in addition to three wireless LANs composed of APs 1 to 3 and wireless terminals 4 to 6. The APs 1 to 3 are connected to the Internet INT via the wired LAN and the router 8. Note that the communication between the APs 1 to 3 is not a mode in which the hub 7 is used to connect via a wired LAN as described above, but a method that enables mutual communication between wireless LAN access points such as WDS (Wireless Distribution System). It may be used and performed wirelessly.

A-2. FIG. 2 shows a schematic electrical block configuration of the above AP1 to AP3. Each of the APs 1 to 3 has a function that can be a server AP. For this reason, since all of AP1 to AP3 have the same electrical block configuration, only the electrical block configuration of AP1 will be described here.

  The AP 1 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a wireless LAN interface (wireless LAN I / F) 14, and a wired LAN interface (wired LAN I / F) 15, a bus 16, and an antenna 17 connected to the wireless LAN interface 14. The CPU 11, ROM 12, RAM 13, wireless LAN interface 14, and wired LAN interface 15 are connected to each other via a bus 16. The ROM 12 stores a control program 18 (corresponding to “program” in claims) and initial setting data, which are programs for controlling the entire apparatus of the AP 1. The control program 18 includes a program for communication control when communicating with an AP in the same segment as the own device. The control program 18 has various function modules, and holds information regarding not only the version of the entire firmware, but also the version of the protocol used by the firmware and the version of the specific function module included in the firmware. The version of the whole firmware, the version of the protocol used by the firmware, and the version of the specific function module included in the firmware correspond to the “program version” in the claims.

  The CPU 11 includes a priority detection unit 21, a transition control unit 22, an information providing unit 23, a multicast information distribution unit 24, and a unicast information distribution unit 25. The CPU 11 controls the overall operation of the AP 1 by expanding and executing the control program 18 stored in the ROM 12 on the RAM 13. Further, the CPU 11 expands and executes the control program 18 stored in the ROM 12 in the RAM 13, thereby executing the priority detection unit 21, the transition control unit 22, the information providing unit 23, the multicast information distribution unit 24, and the unit. It functions as the cast information distribution unit 25.

  The priority detection unit 21 detects whether an AP having a server priority higher than that of the own device is present in the wireless LAN system 10 (in the same segment). When the priority detection unit 21 detects that there is an AP having a higher server priority than the own device (AP1), the transition control unit 22 transitions to the client AP, and the priority detection unit 21 detects When it is not detected that there is an AP having a higher server priority than the machine, control is performed so that the own machine changes to the server AP. The information providing unit 23 transmits, to the server AP, wireless information (PMK (Pairwise Master Key) and beacon information described later) generated by the own device when the own device transits to the client AP. Here, the PMK is a master key used for generating an encryption key used for authentication when a wireless LAN terminal or AP connects to the AP. When performing WPA (Wi-F-Protected Access) -PSK (Pre-Shared Key) authentication, the PSK generated from the passphrase is used as the PMK, and when performing WPA-IEEE802.1x authentication, WPA- The session key distributed after successful IEEE 802.1x authentication is used as the PMK. In addition, when the AP caches the PMK shared between the wireless LAN terminal and the AP that can be connected after successful authentication, the connection destination of the wireless LAN terminal or the like can be determined by roaming or the like. Even when the AP changes, the authentication process can be omitted.

  In addition, the multicast information distribution unit 24 described above receives a part of the received wireless information when the device itself receives the wireless information from the client AP transmitted by the information providing unit 23 after transitioning to the server AP. Is transmitted to all client APs in the wireless LAN system 10 (in the same segment) by multicast transmission. This is to enable the roaming by the wireless terminals 4-6. The unicast information distribution unit 25, when another AP in the wireless LAN system 10 changes to the client AP after the own device changes to the server AP, the PMK that the own device holds to this client AP. (PMK received from the client AP other than the above-mentioned (transitioned) client AP in the wireless LAN system 10 and the PMK generated by itself) are unicast transmitted. This is also to enable the above roaming.

  The wireless LAN interface 14 is a communication control circuit for performing wireless communication conforming to the wireless LAN standard (IEEE802.11), and is a wireless base unit interface (wireless) that operates as an AP in the IEEE802.11 infrastructure mode. A master unit I / F) 14a and a wireless slave unit interface (wireless slave unit I / F) 14b operating as a station in the infrastructure mode of IEEE 802.11. The wireless master device interface 14a functions as a wireless master device, and is used when the AP 1 performs wireless communication with other wireless slave devices (such as the wireless terminal 4) in the wireless LAN to which the own device belongs. . The wireless slave unit interface 14b functions as a wireless slave unit. This wireless slave unit interface 14b is used for receiving beacons (signals) from APs around AP1. When communication between AP1 to AP3 is performed by WDS, wireless base unit interface 14a having a WDS function is used. The wireless master unit interface 14a and the wireless slave unit interface 14b may be configured by one module or may be configured by another module.

  The wired LAN interface 15 is a communication control circuit for performing communication conforming to the standard of the wired LAN. The AP 1 communicates with other APs 2 to 3 and the router 8 via the LAN cable and the hub 7. Used when exchanging information.

A-3. Server AP Selection Processing Next, server AP selection processing performed between the APs 1 to 3 of the wireless LAN system 10 will be described. FIG. 3 is a state (mode) transition diagram of the APs 1 to 3 in the wireless LAN system 10. The server mode in the figure is a mode corresponding to the server AP. The client mode is a mode corresponding to the client AP.

  In the following AP state transition processing (server AP selection processing), a priority detection command that is a command for detecting (notifying) the server priority of the transmission source AP is used. Although details will be described later, this priority detection command packet (hereinafter referred to as a priority detection packet) includes server priority information regarding the transmission source AP of this packet.

  Here, the case where the AP undergoing state transition is AP1 will be described as an example. AP1 operates in the client mode immediately after startup. Then, AP1 does not receive a priority detection packet from an AP having a higher server priority than its own device within a predetermined time x seconds during operation in the client mode (server priority of its own device). Is the highest), transition to the server mode as shown in (2) in the figure. On the other hand, when a priority detection packet is received from an AP having a higher server priority than the own device within x seconds during operation in the client mode, AP1 is indicated by (1). So that the client mode state is maintained.

  In addition, AP1 maintains the server mode state as shown in (4) until it receives a priority detection packet from an AP having a higher server priority than its own when in the server mode. To do. On the other hand, when AP1 receives a priority detection packet from an AP having a higher server priority than its own device in the server mode, it transits to the client mode as shown in (3). .

  Next, with reference to FIG. 4, the state transition process performed in AP1-3 according to said state transition diagram is demonstrated. Here again, the case where the AP undergoing state transition is AP1 will be described as an example. The CPU 11 of the AP 1 stores the last transmission time, which is a work area (on the program) for storing the transmission time of the previous priority detection packet, and the reception time of the previous priority detection packet immediately after activation. Initialize the last reception time, which is a work area to do, and shift to the client mode (S1). Note that the initialization of the last transmission time and the last reception time specifically means that the current time is stored in the last transmission time and the last reception time. Then, the CPU 11 (priority detection unit 21) of AP1 determines whether or not priority detection packets from other APs 2 to 3 have been received (S2).

  As a result of the above determination, when a priority detection packet is received (YES in S2), the CPU 11 (priority detection unit 21) of AP1 determines the priority of the transmission source AP (partner) of the received priority detection packet. Based on the information on the server priority for the transmission source AP included in the received priority detection packet and the information on the server priority of the own device held by the own device, Determine (S3). As a result, if the server priority of the transmission source AP of the received priority detection packet is higher than that of the own device (YES in S3), the CPU 11 of AP1 sets the content of the last reception time as the current time. Update (S4). On the other hand, when the above priority detection packet is not received (NO in S2), or when the server priority of the transmission source AP of the received priority detection packet is lower than the own device (S3) NO), the CPU 11 of AP1 does not update the content of the last reception time.

  Next, the CPU 11 (the transition control unit 22) of the AP 1 determines whether or not a predetermined time x seconds has elapsed from the last reception time (stored time). If x seconds have passed since the last reception time (YES in S5), the CPU 11 of the AP 1 (the transition control unit 22) does not have an AP with a higher server priority than the own device. It is determined that the machine is the server AP (should be selected (selected)) (S6), and transitions to the server mode (if the machine is in the client mode). On the other hand, if x seconds have not elapsed since the last reception time (NO in S5), the CPU 11 (the transition control unit 22) of the AP 1 has an AP having a higher server priority than the own device. Therefore, it is determined that the own device should be the client AP (S7), and transitions to the client mode (if the own device is in the server mode).

  When it is determined that the own device is the server AP in S6, the CPU 11 of AP1 determines the predetermined time y from the last transmission time (the time stored in), that is, the transmission time of the previous priority detection packet. It is determined whether or not more than a second has elapsed (S8). If more than y seconds have elapsed since the last transmission time (YES in S8), the CPU 11 of AP1 transmits a priority detection packet (S9), and the contents of the last transmission time are set to the current time. (S10). When this last transmission time update process or the process of S7 is completed, the CPU 11 of AP1 returns to the process of S2. Further, even when y seconds or more have not elapsed in S8 (NO in S8), the CPU 11 of AP1 returns to the process of S2. Then, the CPU 11 of AP1 repeats the processes of S2 to S10 during operation. When all the APs 1 to 3 execute the processing shown in FIG. 4, the AP having the highest server priority is selected from the APs 1 to 3 as the server AP.

A-3-1. Specific Example of Server AP Selection Process Next, a specific example of the server AP selection process according to the state transition diagram shown in FIG. 3 and the state transition process shown in FIG. 4 will be described.

A-3-1-1. Specific example 1 of server AP selection processing (during independent operation)
If there is only one AP in the same segment, that AP is selected as the server AP. Specifically, when only AP1 exists in the same segment, this AP1 is in the client mode at the time of activation, as shown in S1 of FIGS. Then, the CPU 11 (priority detection unit 21) of AP1 observes whether or not a priority detection packet from an AP having a server priority higher than that of the own device has arrived, so that the server priority of the own device becomes higher. It is detected whether a high AP exists in the wireless LAN system 10 (in the same segment).

  As described above, when only AP1 exists in the same segment, the CPU 11 of AP1 does not receive a priority detection packet from an AP having a server priority higher than that of its own device. For this reason, the CPU 11 (the transition control unit 22) of the AP 1 has no server with higher server priority than the own device when x seconds or more have elapsed from the last reception time (YES in S5). It is determined that the own device should be elected as the server AP (S6), and control is performed so that the own device transitions to the server AP. Further, the CPU 11 of the AP 1 transmits a priority detection packet every y seconds after the own device transitions to the server AP (S8 to S10).

A-3-1-2. Specific example 2 of server AP selection processing (when AP with high server priority is added)
Next, server AP selection processing when AP2 having a higher server priority than AP1 is connected to the wireless LAN system 10 when AP1 is an AP operating in the server mode (server AP) will be described. . The added AP 2 operates in the client mode at the beginning of connection (activation), as indicated by S1. The CPU 11 (priority detection unit 21) of the AP 2 that has entered the client mode receives the priority detection packet from the AP 1 operating in the server mode, and includes the transmission source included in the priority detection packet. Based on the server priority information of AP1, it is determined that the own device has a higher server priority (NO in S3), and the last reception time is not updated. For this reason, when x seconds have elapsed from the last reception time (when AP2 is connected (started up)) (YES in S5), the CPU 11 (transition control unit 22) of AP2 has an AP with a higher server priority than its own device. Since it does not exist, it is determined that the own device should be selected as the server AP (S6), and control is performed so that the own device transits to the server AP. The CPU 11 of the AP 1 transmits a priority detection packet every y seconds after the own device transitions to the server AP (S8 to S10).

  As described above, when AP1 starts transmission of the priority detection packet, the CPU 11 of AP1 operating in the server mode when AP2 is connected transmits the transmission included in the priority detection packet transmitted from AP2. Since the server priority of the original AP2 is higher than that of the own device (YES in S3), the content of the last reception time is updated to the current time (S4). For this reason, in the determination process of S5, since x seconds have not elapsed since the last reception time (NO in S5), the CPU 11 (transition control unit 22) of AP1 has a server priority over its own device. Since there is a high AP, it is determined that the own device should be a client AP (S7), and a transition is made to the client mode.

  As described above, the transition control unit 22 of the CPU 11 of the AP 1 that was operating in the server mode is automatically detected by the priority detection unit 21 when the AP 2 having a higher priority than the own device is connected to the wireless LAN system 10. It detects that AP2 having a higher priority than the device exists, and controls the own device to transition to the client AP.

A-3-1-3. Specific example 3 of server AP selection processing (when server AP leaves)
Next, a server AP selection process when the AP 3 operating in the server mode has left the segment (when the connection of the AP 3 to the wireless LAN system 10 is released) will be described. The withdrawal from the AP3 segment (release of the connection of the AP3 to the wireless LAN system 10) includes a case where the power supply to the AP3 is interrupted. Now, it is assumed that AP1 and AP2 exist in the same segment as the segment where AP3 existed, and the server priority of AP1 is higher than the server priority of AP2. When AP1 and AP2 are disconnected from AP3's wireless LAN system 10 and do not receive a priority detection packet from AP3, which has a higher server priority than their own, for more than x seconds (S5), their own It is determined that the server AP should be elected (S6), the mode is changed to the server mode, and transmission of the priority detection packet is started (S9).

  AP1 and AP2 that have transitioned to the server mode determine which server priority is higher based on the server priority information of the transmission source AP included in the priority detection packet transmitted by each other. Specifically, the priority detection unit 21 of the CPU 11 of the AP 1 determines that the own device has a higher server priority than the AP 2 based on the server priority information included in the priority detection packet transmitted by the AP 2. judge. Further, the priority detection unit 21 of the CPU 11 of the AP 2 determines that the own device has a lower server priority than the AP 1 based on the server priority information included in the priority detection packet transmitted by the AP 1. As a result of these determinations, the CPU 11 (priority detection unit 21) of the AP 1 determined to have a high server priority does not receive a priority detection packet from an AP having a higher server priority than the own device. Therefore (NO in S3), the last reception time is not updated in S4. For this reason, since the state where x seconds or more have elapsed from the last reception time (of the priority detection packet from the AP having higher server priority than the own device) is maintained (YES in S5), the server mode state is changed. maintain. On the other hand, the CPU 11 (priority detection unit 21) of the AP 2 determined to have a low server priority receives a priority detection packet from the AP 1 having a higher server priority than the own device (in S3). YES), the last reception time is updated in S4. For this reason, in the determination process of S5, since x seconds or more have not elapsed since the last reception time (NO in S5), the CPU 11 (transition control unit 22) of AP2 is the client AP. It is determined that it should be (S7), the mode is changed to the client mode, and transmission of the priority detection packet is also stopped.

Through the processing between AP1 and AP2 as described above, AP1 is elected as the server AP, and AP2 transitions to the client AP. That is, when the connection of the AP 3 operating in the server mode to the wireless LAN system 10 is released, the transition control unit 22 of each existing client AP (AP1, AP2) in the wireless LAN system 10 A new server AP is selected from these AP1 and AP2 based on the new detection result by the priority detection unit 21 of AP1 and AP2.

A-3-1-4. Specific example 4 of server AP selection processing (when AP with low server priority is added)
Next, server AP selection processing when AP2 having a lower server priority than AP1 is added to the segment in which AP1 operates in the server mode will be described. When the priority detection unit 21 of the CPU 11 of the added AP 2 receives the priority detection packet from the AP 1 operating in the server mode (S2), the server of the transmission source AP included in the priority detection packet Based on the priority information, AP1 (the other party) determines that the server priority is higher (YES in S3), and updates the last reception time (S4). For this reason, in the determination process of S5, since x seconds or more have not elapsed since the last reception time (NO in S5), the CPU 11 (transition control unit 22) of AP2 is the client AP. It is determined that it should be (S7), and the mode is changed to the client mode. By the processing between AP1 and AP2 as described above, the added AP2 transitions to the client AP, and the state where AP1 is the server AP is maintained.

A-4. Wireless Information Aggregation Processing and Distribution Processing Next, wireless information aggregation processing and distribution processing performed between the server AP and the client AP of the wireless LAN system 10 will be described with reference to FIGS. In this wireless information aggregation process, the wireless information aggregated from the client AP to the server AP includes the beacon information of the APs around the client AP that transmits the wireless information, and the client AP generated (the wireless AP under the control of the client AP). PMK shared with the terminal). Here, the above-mentioned beacon information is information included in the beacon received by each client AP from its surrounding APs, and the BSSID, in-use channel, and beacon (signal) of the beacon transmission source AP. This is information including an RSSI (Received Signal Strength Indicator) value that is a reception strength. The wireless information distributed from the server AP to the client AP includes PMK.

A-4-1. Wireless information aggregation processing and distribution processing performed after transition to the client mode First, wireless information aggregation processing and distribution processing performed when any AP in the wireless LAN system 10 transitions to the client mode This will be described with reference to FIGS. Here, an example will be described in which the AP that has transitioned to the client mode is the client AP 33 in FIG. 9, and the server mode AP is the server AP 31 in FIG. When the client AP 33 transitions to the client mode, the CPU 11 (information providing unit 23) of the client AP 33 has not yet transmitted its own device information to the server AP 31 and needs to transmit its own device information. Is determined (YES in S11), and the own device information is transmitted to the server AP 31 using the own device information transmission command (S12). The self-device information includes a MAC address, an IP address, a BSSID (Basic Service Set Identifier) list (a list of BSSIDs that the client AP 33 has), settable channel information, frequency bandwidth setting information, The setting value information possessed by the AP setting representative device, which will be described later, and the hash value used in the AP setting value sharing process described later are included. The settable channel information is information related to a communication channel that can be used by the client AP 33, and the frequency bandwidth setting information is any frequency bandwidth of 20 MHz, 40 MHz, 80 MHz, and 160 MHz that the client AP 33 uses. It is information that. The server AP 31 registers the own device information in the client information database of the own device.

  Next, the CPU 11 (information providing unit 23) of the client AP 33 determines whether or not there is a PMK that has not been transmitted to the server AP 31 among the PMKs generated by itself and stored in the memory. (S13). As a result, when there is an untransmitted PMK (YES in S13), the untransmitted PMK (generated by the own device) is unicast transmitted to the server AP31 using the untransmitted PMK transmission command. (S14). In addition, although a RADIUS server may be involved in PMK generation, APs (server AP 31 and client APs 32 and 33) are involved in PMK generation. Is used.

  Next, when the CPU 11 (information providing unit 23) of the client AP 33 is permitted to transmit the beacon information (YES in S15), the beacon information is transmitted to the server AP 31 using a beacon information transmission command. Transmit (S16). When “transmission of beacon information is permitted” in S15, the server AP31 requests the client AP33 to transmit beacon information, or the client AP33 periodically transmits beacon information to the server AP31. Is also included. Note that the CPU 11 of the client AP 33 performs channel scan by passive scan using the wireless slave unit interface 14b before the determination processing of S15, and an AP present in a range where wireless communication with the own device can be performed is transmitted. A beacon is received, based on information included in the beacon, beacon information about an AP existing in a range where wireless communication with the own device is possible is generated and stored in the RAM 13 of the own device.

  As shown in FIG. 6, when the CPU 11 (the multicast information distribution unit 24) of the server AP31 receives the new PMK transmitted from the client AP33 in S14 (S21), the received PMK is transmitted to the untransmitted PMK transmission command. Are transmitted to all the client APs (including the client AP 33) in the wireless LAN system 10 by a UDP (User Datagram Protocol) multicast packet (S22).

  Further, as shown in FIG. 7, the CPU 11 (the unicast information distribution unit 25) of the server AP 31 receives the own device information described in FIG. 5 from the client AP 33 that has transitioned to the (new) client mode. When information such as PMK and beacon information is acquired (YES in S31), PMKs generated by all APs belonging to the same RADIUS group as the client AP 33 (managed by the same RADIUS server) among the PMKs owned by the own device are generated. Then, unicast transmission is performed to the client AP 33 using the untransmitted PMK transmission command (S32). Thereafter, the CPU 11 of the server AP 31 uses the information (particularly beacon information) aggregated from the client AP such as the client AP 33 and the information generated by the own device (such as beacon information) to each AP in the wireless LAN system 10. And the transmission output of these APs are calculated (S33), and the channel value and transmission output to be used by these APs are transmitted to each client AP by a channel / transmission output distribution command (S34). ). Each client AP that receives these calculation results changes its own communication channel and transmission output to the communication channel and transmission output received from the server AP31. The calculation of the transmission output in S33 may be performed periodically or based on a request from the client AP.

  Next, referring to FIG. 8 to FIG. 11, wireless information aggregation processing and distribution processing performed when a new client AP 33 is added to the wireless LAN system 10 including the server AP 31 and one client AP 32. Will be described.

  Here, when the client AP 33 in FIG. 8 joins the wireless LAN system 10 (when the client AP 33 transitions to the client mode), the PMK and beacon generated by the server AP 31 are stored in the memory (RAM 13) of the server AP 31. It is assumed that the information and the PMK and beacon information generated by the client AP 32 are stored. At this time, the memory (RAM 13) of the client AP 32 stores the PMK and beacon information generated by the client AP 32 and the PMK and beacon information generated by the server AP 31 as shown in FIG. And Further, the client AP 33 has completed the authentication of the wireless LAN slave device under its control by at least the processing of S13 in FIG. 5 is started, and as shown in FIG. 8, the generated PMK Is stored in the RAM 13 of the own device. Furthermore, as described above, the client AP 33 completes generation of beacon information for an AP existing in a range in which wireless communication with the own device can be performed before the determination process of S15 in FIG. 5 is started, As shown in FIG. 8, it is assumed that it is stored in the RAM 13 of the own device.

  When the own device transitions to the client AP, the information providing unit 23 of the CPU 11 of the client AP 33 converts the information including the PMK and beacon information generated by the own device (client AP 33) into the TCP protocol as shown in FIG. And unicast to server AP31. When the server AP 31 receives the information including the PMK and beacon information transmitted from the client AP 33, the server AP 31 stores the received PMK and beacon information (generated by the client AP 33) in its own RAM 13.

  In addition, the unicast information distribution unit 25 of the CPU 11 of the server AP31 proceeds almost simultaneously with the processing shown in FIG. 9, and the own device (server AP31) generates the client AP33 as shown in FIG. The unicast transmission of the PMK received (collected) from all the client APs (client AP 32 in the example in the figure) other than the client AP 33 in the wireless LAN system 10 using the TCP protocol To do. When the client AP 33 receives the PMK transmitted from the server AP 31, the client AP 33 stores the received PMK (generated by the server AP 31 and the client AP 32) in its own RAM 13.

  Further, when the CPU 11 of the server AP 31 (the multicast information distribution unit 24) completes the reception of the PMK transmitted from the client AP 33 in FIG. 9, it is received (generated by the client AP 33) as shown in FIG. PMK is multicast-transmitted to all client APs (in the example of the figure, client AP 32 and client AP 33 in the figure) by the UDP multicast packet. When the client AP 32 receives the PMK transmitted from the server AP 31, the client AP 32 stores the received PMK (generated by the client AP 33) in its own RAM 13. On the other hand, even if the client AP 33 receives the PMK transmitted from the server AP 31, the received PMK is the PMK already held by the own device (generated by the own device). Discard without storing in RAM 13 of the machine.

  With the PMK multicast transmission process shown in FIG. 11, the PMK aggregated in the server AP 31 can be shared among APs belonging to the same RADIUS group (managed by the same RADIUS server). Thereby, it is possible to prevent a delay in processing due to re-authentication of the wireless LAN client (wireless LAN slave device) during roaming. If each client AP (for example, client AP 32) includes a PMK of a RADIUS group different from its own in the multicast packet transmitted in FIG. 11, the PMK is stored in its own RAM 13. Discard without memorizing.

  In the UDP packet used in the processing of FIG. 11, only data of up to 65 kbytes can be transmitted, so many wireless LAN slave units are connected to the added client AP (client AP33 in the example in the figure). In this case, all PMKs received from the added client AP may not be contained in one UDP (multicast) packet. When the multicast transmission shown in FIG. 11 (and S22 in FIG. 6) shows that the PMK data does not fit in one UDP multicast packet, the CPU 11 (the multicast information distribution unit 24) of the server AP31 sends the PMK data. The data is divided into a plurality of UDP multicast packets and multicast transmitted to all client APs in the wireless LAN system 10.

  On the other hand, each client AP that has received the above-described divided and transmitted UDP multicast packet divides and receives the PMK transmitted from the server AP 31, and combines the divided and received PMK together with its own RAM 13. To store. Thereby, as described above, even when the server AP 31 cannot store the PMK data in one UDP multicast packet and transmits the PMK data divided into a plurality of UDP multicast packets, the client AP All PMKs transmitted from the server AP 31 can be stored in the RAM 13 of the own device.

A-4-2. Wireless information aggregation processing and distribution processing performed after the transition to the client mode In the wireless LAN system 10, not only immediately after any of the above APs transitions to the client mode, but also after this, at a predetermined timing. The wireless information aggregation processing and distribution processing are performed. Of the wireless information aggregation processing and distribution processing after the transition to the client mode, the PMK aggregation processing and distribution processing will be described first. In the wireless LAN system 10, each client AP transmits wireless information (PMK and beacon information) to the server AP31 by the information providing unit 23 immediately after the transition to the client mode, as shown in FIG. After that, when a wireless LAN slave unit is additionally connected at predetermined time intervals or when a wireless LAN slave unit is additionally connected, the PMK for the wireless LAN slave unit connected to the own unit is transmitted to the server AP 31 using the TCP protocol. The PMK transmitted to the server AP server AP31 includes the PMK for the wireless LAN slave device additionally connected to each client AP. The PMK for the additionally connected wireless LAN slave unit is generated when a new wireless LAN slave unit is connected to each client AP.

  On the other hand, when receiving the PMK from each client AP, the server AP 31 multicasts the received PMK to all the client APs in the wireless LAN system 10 by the UDP multicast packet as in FIG. However, the server AP 31 does not perform multicast distribution immediately after receiving the PMK from each client AP, but generates a large number of multicast packets by collectively transmitting undelivered PMKs at predetermined time intervals. Avoid that. As in the case of FIG. 11 described above, when there are many undelivered PMKs and not all PMK data can be sent in one packet, the PMK data is divided into a plurality of UDP multicast packets and The plurality of multicast packets are continuously transmitted without waiting for the predetermined time.

  The PMK transmitted from each client AP to the server AP 31 has a lifetime (lifetime). The CPU 11 of the server AP 31 checks the lifetime for all entries (PMK) periodically (for example, every 5 minutes) for the PMK that the device itself aggregates and stores in the RAM 13. The elapsed entry (PMK) is deleted from the RAM 13 of the own device. For this reason, each client AP connects to its own device every predetermined time after transmitting the wireless information (PMK and beacon information) to the server AP 31 by the information providing unit 23 immediately after the transition to the client mode. The PMKs for all the wireless LAN slave devices that have been sent are transmitted to the server AP 31 using the TCP protocol. As a result, the server AP 31 can always hold the PMKs for all the wireless LAN slaves connected to the client APs even though each PMK has a lifetime.

  Next, of the wireless information aggregation processing after the transition to the client mode, the aggregation processing of beacon information from each client AP will be described. Each client AP unicasts beacon information to the server AP 31 using a beacon information transmission command, not only immediately after the transition to the client mode, but also after this, as in S16 of FIG.

  The reason why each client AP transmits all the generated beacon information not only immediately after transitioning to the client mode as described above but also after that is changed depending on the scanning time. Since the parameter (RSSI value) is included, even when no entry is added (a new BSSID beacon is not received), the beacon stored in the memory (RAM 13) of the server AP 31 at every predetermined time. This is because the information needs to be updated.

A-4-3. Use of Aggregated Beacon Information The beacon information aggregated in the server AP 31 as described above is used when the channel value and the transmission output described in FIG. 7 are calculated.

  In the description of FIG. 7 above, the server AP 31 aggregates beacon information from each client AP, and uses the aggregated beacon information to calculate the communication channel to be used by each AP and to transmit the transmission output of each AP. An example of performing calculations and distributing these calculation results is shown. However, instead of the method as described above, each client AP inquires the server AP 31 about the beacon information necessary for calculating the communication channel to be used by the own device and calculating the transmission output of the own device (transmission request). Each client AP may calculate the communication channel to be used by the own device or the transmission output of the own device based on the beacon information transmitted from the server AP31.

A-5. AP setting value sharing between devices having part of product identification information or the same program version Next, with reference to FIG. 12, AP setting value sharing processing performed between client APs of the wireless LAN system 10 ,explain. This AP setting value sharing is performed between an AP (hereinafter referred to as “the same kind of AP”) in which at least one of a part of product identification information and a version of the program (corresponding to the control program 18 in FIG. 2) is the same. Done. Here, “a part of product identification information is the same” means that part of information such as a series name, a product name, a model number, a MAC address, and a serial number matches. For example, when the product identification information is “abcde-fgh”, the “abcde” part is common, the “abc” part is common, and the “fgh” part is common, It is determined that “a part of the product identification information is the same”.

  In the wireless LAN system 10, any one of the above-mentioned APs of the same type is set as an AP setting representative device that is a representative device of these APs. In the example shown in FIG. 12, the server AP 31 itself does not correspond to the same type of AP, and does not hold an AP setting value that is a common setting value between the same types of APs. Instead, the server AP31 is obtained by performing a calculation using a predetermined hash function for the AP setting value of the AP setting representative device (corresponding to the client AP32 in the figure). (Fixed-length pseudo-random number) and the AP address representative device MAC address and the hash value (of the AP setting value) possessed by each AP of the same type as the AP setting representative device (for example, the client AP 33). doing. Then, if the hash value of the AP setting representative device (client AP 32) is different from the hash value of the same type AP (client AP 33) as the AP setting representative device, the server AP 31 has the same type (other than the AP setting representative device). The AP (client AP 33) is notified of the change of the AP setting value. Here, the hash value is used because it is not necessary to collate the entire data in order to know the change in the AP setting value, and the change in the AP setting value can be detected by the change in the hash value. The AP setting representative device in the above may be set autonomously based on unique information such as a MAC address, or may be set by a user or a device that can communicate with the wireless LAN system 10. May be.

  Specifically, as shown in FIG. 12, when the AP setting value of its own device is changed, the client AP 32, which is the AP setting representative device, uses its own device information transmission command to the server AP 31. A change of the machine status (change of AP setting value) is notified (S61). Upon receiving this notification, the server AP 31 uses the client AP 32 that has transmitted the above setting value change notification as the AP setting representative device among the client APs managed (held) in the client information database. To determine that the client AP 33 is the corresponding client AP (S62). Then, the server AP 31 includes the hash value (of the AP setting value) of the client AP 33 managed (held) by the client device in the client information database in the own device information transmission command transmitted from the client AP 32 in S 61. If it is different from the hash value (of the AP setting value) of the client AP 32, the change of the AP setting value in the AP setting representative device (client AP 32) is notified to the client AP 33 using the AP setting value change notification command. (S63).

  The client AP 33 that has received the change notification checks the hash value (of the AP setting value) included in the change notification, and if this hash value is different from the hash value of the AP setting value of the own device, the AP An AP setting value acquisition request is sent to the set representative device (client AP 32) using an AP setting value request command (S64).

  Upon receiving the acquisition request, the AP setting representative device (client AP 32) sends a response (acquisition response) to the acquisition request using the AP setting value response command to the client AP 33 that has transmitted the acquisition request. Perform (S65). That is, the AP setting representative device (client AP 32) is the same type as the own device (at least one of the product identification information and the program version is the same as the own device) AP setting value from another AP (client AP 33). In response to the acquisition request, the setting value of the own device is transmitted to the client AP 33.

  Note that examples of AP setting values shared between the above-mentioned APs of the same type include setting values for ESSID (ESSID itself, encryption type, password, etc.), RADIUS server setting values (RADIUS server host name, Authentication method, etc.), and an NTP (Network Time Protocol) server setting value (IP address of the NTP server). By sharing these pieces of information between the same types of APs, it is possible to roam between the same types of APs when the user moves with a portable wireless LAN client (wireless LAN slave device).

  In the example shown in FIG. 12, the server AP 31 is not the same kind of AP as the client APs 32 and 33. However, the server AP 31 may be the same kind of AP as the client APs 32 and 33. . When the server AP 31 is the same type of AP as the client APs 32 and 33, the server AP 31 may be a representative device (AP setting representative device) of the same type of AP.

A-6. Commands Used Between APs of the Wireless LAN System Next, commands used between APs in the wireless LAN system 10 will be described with reference to FIG.

A-6-1. Own Device Information Send Command The own device information send command is used when notifying the server AP 31 of own device information of the client AP. This command is unicasted using the TCP protocol. The client AP is connected to the server AP 31 for the first time after its own device transitions to the client mode, when the state of its own device (client AP) changes (when its own device information changes), or for a certain period of time, When the device information transmission command is not transmitted, the device information transmission command is transmitted to the server AP31. When there is a client AP that has not transmitted its own device information transmission command for a certain period of time, the server AP 31 determines that this client AP is not alive (not connected), and client information Information about the corresponding client AP in the database can be deleted.

A-6-2. Unsent PMK Send Command The unsent PMK send command is used to distribute PMKs (particularly, unsent PMKs). This command may be transmitted unicast using the TCP protocol or multicast transmitted using the UDP protocol. As for the case of unicast transmission using the TCP protocol, as shown in S13 in FIG. 5, the client AP notifies the server AP of the PMK, or as shown in S32 in FIG. In some cases, the server AP unicasts the PMK held by the server AP to the new client AP when the new client AP is connected. As a case where multicast transmission is performed using the UDP protocol, there is a case where a new PMK transmitted from the client AP is multicast transmitted to all the client APs, as indicated by S22 in FIG.

A-6-3. Beacon information transmission command The beacon information transmission command is used to distribute beacon information. This command is unicasted using the TCP protocol. Specifically, the beacon information transmission command is used when the client AP transmits the beacon information generated by itself to the server AP as shown in S16 of FIG.

A-6-4. AP setting value change notification command The AP setting value change notification command is used to notify the AP of the same type as the AP setting representative device of the AP setting value change in the AP setting representative device, as shown in S63 of FIG. used. This command is unicasted using the TCP protocol.

A-6-5. AP Setting Value Request Command The AP setting value request command is used when requesting the AP setting representative device to acquire the AP setting value, as indicated by S64 in FIG. This command is also unicasted using the TCP protocol.

A-6-6. AP Setting Value Response Command The AP setting value response command is used when the AP setting representative device responds to the AP setting value acquisition request (command) as shown in S65 in FIG. This command is also unicasted using the TCP protocol.

A-6-7. Channel / transmission output distribution command The channel / transmission output distribution command is used for the server AP to calculate the communication channel to be used by each client AP for each client AP in the same segment, and the transmission of these client APs. Used to distribute (notify) output calculation results. This command is also unicasted using the TCP protocol.

A-6-8. Priority detection command The priority detection command is used by each AP of the wireless LAN system 10 to notify its own server priority. As described with reference to FIGS. 3 and 4 above, each AP in the wireless LAN system 10 determines whether or not the server AP is based on the server priority information included in the priority detection command packet (priority detection packet). To elect. This command is sent in multicast using the UDP protocol.

  FIG. 14 shows the format of the payload of the priority detection packet. The payload of the priority detection packet includes a transmission source IP address 41, a device specific priority 42, and a transmission source MAC address 43.

  The transmission source IP address 41 is the IP address of the transmission source of this priority detection packet. The device specific priority 42 is information on the priority set for each AP model and each version of the program of the AP. In the case of a product of the same type (a product to which the same type of firmware is applied), the device-specific priority 42 is higher for a product loaded with a newer version of the program. This “same type of product” has the same meaning as the above-mentioned “part of the product identification information is the same” product. It is a matching product. The version of this program (corresponding to the “program version” in the claims) includes not only the version of the entire firmware but also the version of the protocol used by the firmware and the version of the specific function module included in the firmware. It is. Accordingly, when (1) the protocol version is changed or (2) the version of a specific functional module is changed, the device specific priority 42 is updated (new). The case (1) includes a case where transmission / reception information between the server AP and the client AP is changed. The case (2) includes a case where the channel calculation algorithm or the (radio wave) transmission output calculation algorithm is changed. The source MAC address 43 is the MAC address of the AP that is the source of this priority detection packet.

A-6-4-1. Server priority determination rule using device-specific priority The server AP 31 is selected based on the following server priority determination rule.
(A) When priority detection packets are transmitted from a plurality of APs within the same segment, the server priority is higher for an AP having a higher device-specific priority value 42 included in the priority detection packet. .
(A) When the device-specific priority 42 included in the priority detection packets transmitted from a plurality of APs has the same value, the AP having the smaller source MAC address 43 included in the priority detection packet shown in FIG. However, the server priority is high.

  The priority detection unit 21 of each AP in the wireless LAN system 10 determines the above rule (a) when a plurality of APs in the system are the same type of product (a product to which the same type of firmware is applied). Used to determine the server priority of these APs based on the version of the program (such as firmware) that these APs have. In addition, the priority detection unit 21 of each AP is configured so that when a plurality of APs in the wireless LAN system 10 are the same type of products as described above and the device-specific priority 42 has the same value (the APs have (such as firmware) ) When the program versions are the same), the server priority of these APs is determined based on the MAC address values of these APs using the above rule (A). In the following description, “version of a program such as firmware” includes not only the version of the entire firmware but also the version of the protocol used by the firmware and the version of a specific functional module included in the firmware.

A-6-4-2. Specific Example of Server Priority Determination Next, a specific example of the server priority determination will be described. For example, assume that the following four APs exist in the same segment as follows. Note that all APs in the following (A) to (D) are products of the same model.
(A) AP with a version 3.0.2 of a program such as firmware and a source MAC address of 00: 00: 00: 00: 00: 03
(B) AP with version 3.0.2 of the program such as firmware and the source MAC address of 00: 00: 00: 00: 00: 04
(C) AP with version 3.0.1 of the program such as firmware and the source MAC address of 00: 00: 00: 00: 00: 01
(D) AP having a version 3.0.1 of a program such as firmware and a source MAC address of 00: 00: 00: 00: 00: 02

  Based on (a) of the above server priority determination rule, the priority detection unit 21 of each AP in the wireless LAN system 10 uses a new (3.0.2) AP ( Since the value of the device specific priority 42 is larger in A) and (B) than in AP (C) and (D) (3.0.1), it is determined that the server priority is high. Also, based on (i) of the server priority determination rule, the priority detection unit 21 of each AP in the wireless LAN system 10 uses the same version of the program such as firmware (A), (B) Among them, the numerical values when the hexadecimal values constituting the source MAC address are connected are compared, and the smaller AP (A) is determined to have higher server priority. For the same reason, the priority detection unit 21 of each AP in the wireless LAN system 10 has the same version of the program such as firmware, AP (C), (D), whichever has the smaller source MAC address. AP (C) is determined to have higher server priority. Therefore, the server priorities of the APs (A) to (D) are (A)> (B)> (C)> (D).

  In the above example, when the device-specific priority value 42 of each AP in the wireless LAN system 10 is the same (when the version of the program such as firmware is the same), these are based on the MAC address value of each AP. However, the server priority of these APs may be determined based only on the value of the MAC address of each AP in the wireless LAN system 10.

A-7. Summary of the present embodiment As described above, according to the AP in the wireless LAN system 10 of the present embodiment, when the own device transitions to the client AP, the PMK and beacon information generated by the own device is transmitted to the server AP 31. In addition, when the PMK and the beacon information are received from the client AP after the own device transitions to the server AP 31, the received PMK is multicast transmitted to all the client APs in the wireless LAN system 10. As a result, the PMK and beacon information generated by each client AP in the wireless LAN system 10 is aggregated in the server AP, and among the aggregated information, the PMK is assigned to all the client APs in the wireless LAN system 10. Can be distributed by multicast transmission. Therefore, the PMK generated by each client AP can be shared among all APs in the wireless LAN system 10.

  Moreover, according to the AP in the wireless LAN system 10 of the present embodiment, unlike the AP in the wireless LAN system in which wireless information is sent between all the conventional APs in a multicast packet, only the server AP 31 transmits the multicast packet. Since transmission is performed, it is possible to reduce the load on the network.

  Further, according to the AP in the wireless LAN system 10 of the present embodiment, after the own device transitions to the server AP 31, another AP in the wireless LAN system 10 (for example, the client AP 33 in FIG. 9) When the transition is made, the PMK received by the own device from the client AP other than the client AP (for example, the client AP 32 in FIG. 9) in the wireless LAN system 10 The PMK generated by itself is unicasted. Thereby, the PMK generated by each AP can be shared among all APs including the server AP 31 in the wireless LAN system 10.

  Further, according to the AP in the wireless LAN system 10 of the present embodiment, PMK is included in the wireless information that is multicast-transmitted by the multicast information distribution unit 24 of the server AP31. As a result, the PMK aggregated in the server AP 31 can be shared among the APs in the system, so that it is possible to prevent a delay in processing due to re-authentication of the wireless LAN client during roaming.

  Further, according to the AP in the wireless LAN system 10 of the present embodiment, when the own device is a client AP, the PMK and beacon information generated by the own device is transmitted to the server AP 31 when the own device transits to the client AP. After that, when a wireless LAN slave unit is additionally connected at a predetermined time or when a wireless LAN slave unit is additionally connected, the PMK for the wireless LAN slave unit connected to the own unit is transmitted to the server AP31. As a result, the server AP 31 can always hold the PMK for all the wireless LAN slave devices connected to each client AP.

  Further, according to the AP in the wireless LAN system 10 of the present embodiment, the wireless information transmitted from the client AP to the server AP 31 includes an AP that exists in a range where wireless communication can be performed with the client AP that transmits the wireless information. The beacon information to be transmitted is included. As a result, the server AP 31 can calculate the communication channel to be used by each client AP and the transmission output of each client AP using the received beacon information.

  In addition, according to the AP in the wireless LAN system 10 of the present embodiment, the multicast information distribution unit 24 of the server AP 31 performs PMK data transmission when PMK data does not fit in one UDP multicast packet during PMK multicast transmission. Is divided into a plurality of UDP multicast packets, and multicast transmission is performed to all client APs in the wireless LAN system 10. When each client AP receives the wireless information transmitted in a divided manner, each client AP combines the received PMK and stores it in its own memory (RAM 13). Thereby, as described above, even when the server AP 31 cannot store the PMK data in one UDP multicast packet and transmits the PMK data divided into a plurality of UDP multicast packets, the client AP All PMKs transmitted from the server AP 31 can be stored in the RAM 13 of the own device.

  Further, according to the APs in the wireless LAN system 10 of the present embodiment, the priority detection unit 21 determines the server priority of these APs based on the MAC address value of each AP in the wireless LAN system 10. I tried to do it. Thereby, since the server priority of each AP can be reliably distinguished, the server AP 31 can be easily selected.

B. Variation:
In addition, this invention is not restricted to the structure of said embodiment, A various deformation | transformation is possible in the range which does not change the meaning of invention. Next, a modified example of the present invention will be described.

B-1. Modification 1:
In the above embodiment, as shown in S39 and S42 of FIG. 7, when the information providing unit 23 of the client AP transmits PMK and beacon information to the server AP 31, these information are stored in separate commands (unrepresented). Using a transmission PMK transmission command and a beacon information transmission command), transmission was performed separately. However, the client AP (the information providing unit 23) may transmit the PMK and the beacon information collectively using one command.

B-2. Modification 2:
In the above embodiment, the server AP 31 uses the beacon information aggregated from each client AP to calculate a communication channel to be used by each client AP and to calculate the transmission output of each client AP. An example in which the result is distributed to each client AP is shown. However, instead of the method described above, after the server AP 31 aggregates the beacon information from each client AP, each client AP calculates the communication channel to be used by itself and calculates its own transmission output. The server AP31 is inquired about the necessary beacon information (requested for transmission), and each client AP should use its own device based on the beacon information sent from the server AP31 (transmitted in the form of a response). The communication channel may be calculated or the transmission output of the own device may be calculated.

B-3. Modification 3:
In the above embodiment, when the server AP 31 receives wireless information (PMK and beacon information) from the AP that has newly transitioned to the client AP, only the PMK of the received wireless information is wirelessly transmitted by the UDP multicast packet. Multicast transmission to all client APs in the LAN system 10 was performed. However, when the server AP 31 receives the wireless information (PMK and beacon information) from the AP that has newly transitioned to the client AP, all of the received wireless information (both PMK and beacon information) is received by the UDP multicast packet. Multicast transmission may be performed to all client APs in the wireless LAN system 10.

B-4. Modification 4:
In the above embodiment, the priority detection unit 21 of each AP includes the transmission level included in the priority detection packet when the device-specific priority values 42 included in the priority detection packets transmitted from a plurality of APs are the same. The AP with the smaller original MAC address 43 is determined to have a higher server priority. However, the priority detection unit 21 of each AP, when the device-specific priority values included in the priority detection packets transmitted from a plurality of APs are the same, the AP having the larger transmission source MAC address has the server priority. May be determined to be high.

B-5. Modification 5:
In the above embodiment, the client AP performs channel scan by passive scan, and generates beacon information of the AP that exists in a range where wireless communication with the own device can be performed. However, by performing channel scan by active scan, Information corresponding to beacon information may be generated. That is, the client AP uses the wireless slave unit interface 14b to transmit a probe request using each channel in the usable range, and based on the probe response transmitted from the surrounding AP that has received the probe request. , Information similar to the beacon information (information including the BSSID, the channel being used, and the RSSI value that is the reception intensity of the probe response (signal) for the AP that is the probe response transmission source) may be generated. .

B-6. Modification 6:
In the above embodiment, an example in which the storage medium for each AP to store PMK and beacon information is a RAM, but a nonvolatile memory such as a flash ROM may be used instead of the RAM. Good. This makes it possible to quickly perform a retry when a power interruption occurs in the middle of PMK and beacon information aggregation processing or PMK distribution processing.

B-7. Modification 7:
The present invention can be realized in various forms, for example, in the form of an information distribution method, an AP control program, a recording medium on which the AP control program is recorded, and the like.

4-6 Wireless terminal (wireless LAN handset)
10 Wireless LAN system 13 RAM (memory)
18 Control program (program, firmware)
21 Priority detection unit 22 Transition control unit 23 Information providing unit 24 Multicast information distribution unit 25 Unicast information distribution unit 31 Server AP (server access point)
32 Client AP (client access point, representative device)
33 Client AP (Client Access Point)
43 Source MAC address (MAC address)
AP 1-3 access point

Claims (14)

An access point in a wireless LAN system comprising a server access point that is an access point on the information aggregating side and a client access point that is an access point on the information providing side,
A priority detection unit for detecting whether or not an access point having a higher priority than the own device exists in the wireless LAN system;
When the priority detection unit detects that there is an access point with a higher priority than the own device, the priority detection unit makes a transition to the client access point, and the priority detection unit detects an access point with a higher priority than the own device. A transition control unit that controls to transition to the server access point when it cannot be detected.
An information providing unit that transmits wireless information to the server access point, which is information related to wireless LAN communication, generated by the own device when transitioning to the client access point;
After the transition to the server access point, when receiving the wireless information from the client access point transmitted by the information providing unit, at least a part of the received wireless information is stored in the wireless LAN system. An access point comprising a multicast information distribution unit for multicast transmission to all client access points.   After the own device transits to the server access point, when another access point in the wireless LAN system transits to the client access point, the own device possesses this client access point. The access point according to claim 1, further comprising a unicast information distribution unit configured to unicast transmit at least a part of the wireless information.   The access point according to claim 1 or 2, wherein the wireless information multicast-transmitted by the multicast information distribution unit includes a PMK (Pairwise Master Key).   When the own device is the client access point, after transmitting the wireless information to the server access point by the information providing unit, the wireless LAN slave device connected to the own device every predetermined time The access point according to claim 3, wherein PMK is transmitted to the server access point.   2. The wireless information transmitted by the information providing unit includes beacon information transmitted by an access point existing in a range where wireless communication can be performed with a client access point that transmits the wireless information. The access point according to claim 4. The multicast information distribution unit multicasts the wireless information by a UDP (User Datagram Protocol) multicast packet. When the wireless information does not fit in one UDP multicast packet at the time of multicast transmission, the multicast information distribution unit transmits the wireless information. , Dividing into a plurality of UDP multicast packets, and multicasting to all client access points in the wireless LAN system,
Each of the client access points, when receiving the wireless information divided and transmitted by the multicast information distribution unit, stores the wireless information divided and received together in its own memory, The access point according to any one of claims 1 to 5.   When the own device is the server access point, the transition control unit prioritizes the own device by the priority detection unit when an access point having a higher priority than the own device is connected to the wireless LAN system. The access point according to any one of claims 1 to 6, wherein the access point is detected so that an access point having a high degree of presence exists, and is controlled so as to transition to a client access point. .   When the connection of the server access point to the wireless LAN system is released, the transition control unit of each existing client access point in the wireless LAN system uses the priority detection unit of these client access points. The access point according to any one of claims 1 to 7, wherein a new server access point is selected from these client access points based on a new detection result obtained by.   9. The priority detection unit according to claim 1, wherein the priority detection unit determines the priority of each access point based on a program version of each access point in the wireless LAN system. The access point according to one item.   The priority detection unit determines the priority of each access point based on the MAC address value of each access point in the wireless LAN system. The access point according to one item.   Each access point in the wireless LAN system shares a setting value with another access point in which at least one of a part of product identification information and a program version is the same as its own device. The access point according to any one of claims 1 to 10.   One of the access points that share the setting value is set as a representative device of these access points, and this representative device has at least one of the product identification information and at least one of the program versions. 12. The access point according to claim 11, wherein the setting value of its own device is transmitted to the other access point in response to a setting value acquisition request from another access point that is the same as the device. From the client access point that is the information providing side access point to the server access point that is the information aggregating side access point, the wireless information that is information related to wireless LAN communication is aggregated, and the aggregated wireless information is An information delivery method for delivering from a server access point to the client access point,
The client access point transmits the wireless information generated by itself to the server access point;
When the server access point receives wireless information from the client access point, at least part of the received wireless information is transferred to all client access points in the wireless LAN system to which the own device is connected. And multicast transmission to the information distribution method. A program for controlling each access point in a wireless LAN system, including a server access point that is an access point on the information aggregating side and a client access point that is an access point on the information providing side,
Each access point in the wireless LAN system is
A priority detection unit for detecting whether or not an access point having a higher priority than the own device exists in the wireless LAN system;
When the priority detection unit detects that there is an access point with a higher priority than the own device, the priority detection unit makes a transition to the client access point, and the priority detection unit detects an access point with a higher priority than the own device. A transition control unit that controls to transition to the server access point when it cannot be detected.
When the transition is made to the client access point, the information providing unit for transmitting to the server access point wireless information, which is information related to wireless LAN communication generated by the own device, and the server access point has been transitioned to Later, when wireless information transmitted from the information providing unit is received from the client access point, at least part of the received wireless information is multicast to all the client access points in the wireless LAN system. An access point control program for functioning as a multicast information distribution unit for transmission.

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