Relay and communication system

The present invention relates to a relay device and a communication system, and more particularly to a relay device and a communication system capable of switching between two wireless communication methods.

[0002] Conventionally, in a wireless LAN access point, when the number of connectable clients is defined and access is performed to the wireless LAN access point from clients exceeding the number of clients, the wireless LAN access point is accessed. A technique for improving throughput by blocking connection requests from wireless LAN access points has been developed (see Patent Document 1).

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 11-55286 (1st page) [0004] [Problems to be Solved by the Invention] However, in the above-mentioned technology, a client that can access a wireless LAN access point Since access is restricted only by the number of access points, for example, clients that connect to the access point only browse the web, or clients that use only email, etc., have relatively low traffic. Access is restricted even when connected.

[0005] Since such clients have a small amount of communication, the throughput does not decrease even if the number of connections exceeds a predetermined number of clients. As a result, there is a problem that access is restricted even though the communication band has a margin, and the communication band cannot be effectively used.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a relay device and a communication system capable of effectively utilizing a band.

[Means for Solving the Problems] Therefore, in order to achieve the above object, according to the present invention,<u style="single">A communication unit capable of communicating by the first communication method, a means for detecting that the communication amount of the communication band used in the first communication method exceeds a predetermined communication amount, and the predetermined communication amount. When it is detected that the error has been exceeded, a means for rejecting the association request from the client device using the first communication method and limiting the communication amount of the communication band of the first communication method by the client device. When the association request is rejected, a means for transmitting an error message to the client device using the first communication method and an association request for responding to the error message from the client device as a second communication method are used. A relay device including means for receiving using and associating with the client device by the second communication method.</u>,.

[0008] Further, the present invention<u style="single">In the communication control method in the wireless relay device capable of communicating with the client device by the first communication method, it is detected that the communication amount of the communication band used in the first communication method exceeds a predetermined communication amount, and the above-mentioned When it is detected that the predetermined communication amount is exceeded, the client device requesting a wireless communication connection and the client device wirelessly communicate with each other according to a second communication method different from the first communication method. Communication control method,</u>Is.

[Embodiment of the Invention] &lt;First Embodiment&gt; Hereinafter, a wireless LAN system according to the first embodiment of the present invention will be described with reference to the drawings.

[0010] FIG. 1 is a diagram showing a wireless LAN system according to a first embodiment of the present invention.

As shown in the figure, the wireless LAN system according to the embodiment of the present invention includes an access point 1 and clients 2a to 2e that wirelessly access the access point.

[0012] The access point 1 includes a communication I / F unit 11, a relay unit 12, a control unit 13, a memory 14, and a LAN I / F unit 15.

[0013] The communication I / F unit 11 is an interface for communicating with the clients 2a to 2e.

[0014] The relay unit 12 performs relay processing between the wireless LAN configured by the clients 2a to 2e and the wired LAN 21 and also performs routing processing in the wireless LAN.

[0015] The control unit 13 controls the entire wireless LAN access point 1 and executes the operation of the wireless LAN system according to the embodiment of the present invention. This process will be described later.

[0016] The memory 14 is used by the processing in the relay unit 12 and the control unit 13, and stores the table used in the embodiment of the present invention.

[0017] The LAN I / F unit 15 is an interface for communicating between the access point 1 and the wired LAN 21.

FIG. 2 is a functional block diagram of the access point 1 according to the first embodiment of the present invention.

As shown in the figure, the access point 1 according to the embodiment of the present invention includes a communication unit 31, a communication volume detection unit 32, an association request rejection unit 33, a message transmission unit 34, and an association unit 35. ing.

[0020] The communication unit 31 performs wireless communication between the access point and the client, and includes two communication methods, the IEEE802.11a communication unit 31a and the IEEE802.11b communication unit 31b.

[0021] The IEEE802.11a communication unit 31a performs communication according to the communication method of IEEE802.11a.

[0022] The IEEE802.11b communication unit 31b performs communication according to the communication method of IEEE802.11b.

[0023] The communication volume detection unit 32 detects the communication volume by the IEEE 802.11a communication unit 31a and the IEEE 802.11b communication unit 31b. Specifically, the communication amount detection unit 32 detects that the usage amount of the communication band of the IEEE802.11a communication unit 31a exceeds a predetermined usage amount. In addition, it detects that the usage amount of the communication band of the IEEE802.11b communication unit 31b exceeds a predetermined usage amount. Here, the predetermined usage amount is arbitrarily determined, but is determined, for example, a data communication amount of 20 MB per minute.

[0024] The association request rejection unit 33 rejects the association request from the client when it is detected by the communication volume detection unit 32 that the usage amount exceeds a predetermined amount.

[0025] Specifically, when the association request rejection unit 33 detects by the communication volume detection unit 32 that the usage amount of the communication band of the IEEE802.11a communication unit 31a exceeds a predetermined usage amount, the association request rejection unit 33 , Rejects association requests from clients in the IEEE802.11a communication band. If it is detected that the usage of the communication band of the IEEE802.11b communication unit 31b exceeds the predetermined usage, the association request from the client in the communication band of IEEE802.11b is rejected.

[0026] When the association is rejected by the association request rejection unit 33, the message transmission unit 34 transmits a message to the effect that communication should be performed by another communication method. Specifically, when the message transmission unit 34 rejects the association request in the communication band of IEEE802.11a, the message transmission unit 34 transmits a message in the communication band of IEEE802.11a to the client that issued the association request. If the association request is rejected in the IEEE802.11b communication band, a message is sent to the client that issued the association request in the IEEE802.11b communication band.

[0027] The association unit 35 responds to the message transmitted by the message transmission unit 34 by a communication method different from the communication method in the first association request, and performs the association by the association request transmitted from the client.

Next, the operation of the wireless LAN access point according to the first embodiment of the present invention will be described with reference to the flowcharts of FIGS. 3 and 4.

[0029] First, it is determined whether or not the association request has been issued by the client by the method of IEEE802.11a (S1). If it is determined in S1 that it has not been issued, the process proceeds to S5, which will be described later.

[0030] On the other hand, when it is determined that the association request has been issued in S1, it is determined whether or not the communication amount in the band of IEEE802.11a is equal to or more than the predetermined communication amount (S2).

[0031] If it is determined in S2 that the amount of communication is not more than the predetermined amount, the association is started by the method of IEEE802.11a (S3). On the other hand, when it is determined that an association request has been issued in S2, it is determined that the traffic in the IEEE802.11a band is congested with a predetermined traffic or more. Reject association requests issued by the method (S4).

Then, an error message indicating that communication should be performed by another communication method in the band of IEEE802.11a is transmitted to the wireless LAN client that issued the association request (S5). The content of the error message here is a message prompting reconnection in the communication band of IEEE802.11a because the communication band of IEEE802.11a is congested.

Next, in response to the error message, it is determined whether or not the association request has been issued by the method of IEEE802.11b (S6). If it is determined in S6 that an association request has been issued using the IEEE802.11b method, then it is determined whether or not the amount of communication in the IEEE802.11b band is greater than or equal to the specified amount (S7). ), If it is detected that the amount of communication exceeds the specified amount, the association request issued by the method of IEEE802.11b is rejected (S9). On the other hand, in S6, when it is determined that the association request has not been issued, the process returns to the processing of S1.

[0034] In S9, after rejecting the association request, an error message is sent from the wireless LAN access point to the wireless LAN client that issued the association request (S10), and the process returns to S1.

By performing such an operation on the wireless LAN access point, when the communication volume exceeds a predetermined amount in a certain band, the association request in that band is not accepted and the association is performed in another band. By doing so, the communication band can be controlled.

Next, the operation of the wireless LAN client will be described with reference to the flowchart of FIG.

First, it is determined whether or not an error message has been received from the wireless LAN access point by the method of IEEE802.11a (S21). If it is determined that an error message has been received in S21, the wireless connection of IEEE802.11a is blocked and an association request is sent to the wireless LAN access point by the method of IEEE802.11b (S22). Then, after that, the association is started by the method of IEEE802.11b (S23).

[0038] On the other hand, when it is determined that the error message has not been received in S21, it is determined whether or not the error message has been received from the wireless LAN access point by the method of IEEE802.11b (S24).

[0039] When it is determined in S24 that an error message has been received, the wireless connection of IEEE802.11b is cut off, and an association request is transmitted to the wireless LAN access point by the method of IEEE802.11a (S25).

After that, the association is started by the method of IEEE802.11a (S26), and the process returns to the process of S21. On the other hand, if it is determined in S24 that the error message has not been received, the process proceeds to S21.

Therefore, according to the wireless LAN system according to the embodiment of the present invention, when the wireless LAN client receives the error message transmitted from the wireless LAN access point, the wireless LAN client associates with another communication method. , The wireless communication band can be controlled.

&lt;Second Embodiment&gt; Next, the wireless LAN system according to the second embodiment of the present invention will be described. The hardware configuration of the wireless LAN system according to the embodiment of the present invention is the same as that shown in FIG.

[0043] In the first embodiment described above, when the communication volume is equal to or greater than a predetermined value, the client does not allow the association of the client to be associated, and the client sends a message to cause the association to be performed in another communication method. The case of sending to is explained.

[0044] In the wireless LAN system according to the second embodiment of the present invention, a case where a client that has already been associated is disassociated from the access point side will be described.

FIG. 6 is a functional block diagram of an access point in a wireless LAN system according to a second embodiment of the present invention.

As shown in the figure, the access point 1 according to the embodiment of the present invention includes a communication unit 41, a communication amount detection unit 42, an electric field strength measurement unit 43, a communication time measurement unit 44, a table 45, and a client selection. The communication unit 41, which includes a unit 46, an association unit 47, a message transmission unit 48, and a wireless connection blocking unit 49, performs wireless communication between the access point and the client, and is two communication methods, IEEE802. It is equipped with a .11a communication unit 41a and an IEEE 802.11b communication unit 41b.

[0047] The IEEE802.11a communication unit 41a performs communication according to the communication method of IEEE802.11a.

[0048] The IEEE802.11b communication unit 41b performs communication according to the communication method of IEEE802.11b.

The communication volume detection unit 42 detects the communication volume by the IEEE 802.11a communication unit 41a and the IEEE 802.11b communication unit 41b. Specifically, the communication amount detection unit 42 detects that the usage amount of the communication band of the IEEE802.11a communication unit 41a exceeds a predetermined usage amount. It also detects that the usage of the communication band of the IEEE802.11b communication unit 41b exceeds the predetermined usage.

[0050] The electric field strength measuring unit 43 measures the electric field strength of the radio wave transmitted from the client.

[0051] The communication time measuring unit 44 measures the communication time with each of the plurality of associated wireless LAN clients.

[0052] Table 45 stores the priorities of a plurality of associated wireless LAN clients. For example, as shown in FIG. 6, the client numbers "1" and "2" have the priority "A", the client number "3" has the priority "C", and the client number "4" has the priority "B". Is set to.

[0053] In FIG. 6, the electric field strength measuring unit 43, the communication time measuring unit 44, and the table 45 are shown, and these have functions corresponding to the client selection method in the client selection unit 46. All you have to do is prepare.

That is, when the client selection unit 46 selects the client based on the electric field strength, it is sufficient to have only the electric field strength measurement unit 43, and when the client is selected based on the communication time, the client selection unit 46 needs to have only the electric field strength measurement unit 43. , It suffices to have only the communication time measuring unit 44.

[0055] The client selection unit 46 selects a wireless LAN client to be disassociated from a plurality of wireless LAN clients currently associated according to a predetermined selection method.

[0056] For example, when selecting a wireless LAN client to disassociate based on the electric field strength, the wireless LAN having the lowest electric field strength among the electric field strengths of the plurality of wireless LAN clients measured by the electric field strength measuring unit 43. Select a client.

[0057] Further, when selecting based on the communication time, the wireless LAN client having the shortest communication time is selected from the communication times of the plurality of wireless LAN clients measured by the communication time measuring unit 44.

[0058] Further, when selecting based on the priority, the wireless LAN client having the lowest priority is selected by referring to the table 45 in which the client number and the priority are associated with each other.

[0059] When the client is selected by the client selection unit 46, the message transmission unit 48 transmits a message prompting reconnection by the current communication method. The message prompting the reconnection may include information indicating which communication method is used for reconnection, information indicating the access point to be reconnected, and the like.

[0060] The wireless connection blocking unit 49 blocks communication with a client selected by the client selection unit 46 after transmitting a message by the message transmitting unit 48.

Next, the operation of the wireless LAN system according to the second embodiment of the present invention will be described with reference to the flowchart of FIG. 7.

[0062] It is determined whether or not the communication amount in the band of IEEE802.11a is equal to or more than the predetermined communication amount (S31). If it is determined in S31 that the amount of communication exceeds a predetermined amount, a client to disassociate is selected (S32).

[0063] This method of selecting a client is performed according to one of the following rules.

[0064] 1. Measure the electric field strength of radio waves transmitted from a plurality of associated wireless LAN clients, and select the wireless LAN client that transmitted the radio wave having the lowest electric field strength among the measured electric field strengths.

2. Measure the communication time with a plurality of associated wireless LAN clients, and select the wireless LAN client with the shortest communication time from the measured communication times.

3. Refer to the table that stores the priorities of the plurality of associated wireless LAN clients, and select the wireless LAN client with the lowest priority.

After that, an error message is sent to the selected client (S33). The content of the error message here is a message prompting reconnection in the communication band of IEEE802.11b because the communication band of IEEE802.11a is congested.

Then, the wireless connection with the selected client is cut off (S34), and in response to the error message, it is determined whether or not the association request has been issued by the communication method of IEEE802.11b (S35). ..

[0069] If it is determined in S35 that the association request has not been issued, the process returns to the process of S31. On the other hand, in S35, when it is determined that the association request has been issued, the association is started with the client by the communication method of IEEE802.11b (S36), and the process returns to the processing of S31.

[0070] On the other hand, in S31, when it is determined that the communication amount is not equal to or more than the predetermined communication amount, it is determined whether or not the communication amount in the band of IEEE802.11b is equal to or more than the predetermined communication amount (S37). If it is determined in S37 that the amount of communication exceeds a predetermined amount, a client to disassociate is selected (S38). The method of selecting this client is as described in S32.

After that, an error message is sent to the selected client (S39). The content of the error message here is a message prompting reconnection in the communication band of IEEE802.11a because the communication band of IEEE802.11b is congested.

Then, the wireless connection with the selected client is cut off (S40), and in response to the error message, it is determined whether or not the association request has been issued by the communication method of IEEE802.11a (S41). ..

[0073] If it is determined in S41 that the association request has not been issued, the process returns to the process of S31. On the other hand, in S41, when it is determined that the association request has been issued, the association is started with the client by the communication method of IEEE802.11b (S42), and the process returns to the processing of S31.

Therefore, according to the wireless LAN system according to the second embodiment of the present invention, when a certain communication band is congested, the access point reconnects to the client in another communication band. Since it is possible to send a message prompting the user and block the connection with the client that has already been associated, the communication band can be effectively used.

[0075] In the above-described embodiment, the access point determines the communication status, and the connection form is changed by the action of the access point. However, the client grasps the situation and sets the connection form by itself. You may want to make changes.

[0076] In wireless LAN communication, the access point operates as a bridge or dam hub (sending all packets by broadcasting) instead of a switching hub (sending packets only to the corresponding port by looking at the MAC address). Therefore, the packet received by the access point and the packet received by the client are the same.

[0077] However, this does not apply when the hidden station problem occurs. Therefore, it is sufficiently possible for the client side to make a judgment regarding the amount of communication. Rather, the client side may make settings according to their own use.

[0078] For example, if you are a user who wants to use IEEE802.11a if possible for printing or transferring large files, although you only need to read emails, from the crowded IEEE802.11a path. , You may decide that the IEEE802.11b path is better.

[0079] On the contrary, the client performing the video transfer which is meaningless without the band of IEEE802.11a is set so as to never shift to IEEE802.11b. In this case, the client determines the amount of communication, disassociates the connection with IEEE802.11a by itself, and shifts to IEEE802.11b.

[0080] FIG. 8 is a flowchart for explaining an operation in which a client determines a communication amount and cuts off a wireless connection.

As shown in the figure, first, it is determined whether or not the communication amount in the band of IEEE802.11a is a predetermined communication amount (S51). If it is determined in S51 that the amount of communication exceeds the predetermined amount, the wireless connection of IEEE802.11a with the access point is cut off (S52), and the process returns to S51.

On the other hand, when it is determined in S51 that the communication amount is not equal to or more than the predetermined communication amount, it is determined whether or not the communication amount in the band of IEEE802.11b is equal to or more than the predetermined communication amount (S53).

[0083] If it is determined in S53 that the amount of communication is not more than the predetermined amount, the process returns to the process of S51. On the other hand, if it is determined in S52 that the amount of communication exceeds a predetermined amount, the wireless connection of IEEE802.11b with the access point is cut off (S54), and the process returns to S51.

[0084] In the above-described embodiment, the case where the wireless LAN access point and the client switch between the two communication methods based on the amount of communication has been described, but the number of communication methods is not limited to two. Absent. That is, the communication method may be two or more, and in the case of two or more, a message prompting reconnection to the communication method that uses the least congested band is inserted in the error message. You may try to do so. By doing so, the client can connect to the access point by the most appropriate communication method.

[0085] Further, in the above-described embodiment, the case where one access point communicates by two communication methods has been described, but even if the access point has only a function of communicating by one communication method. Good. In this case, the access point sends an error message to the client to reconnect by another communication method when the communication volume exceeds the predetermined amount, and the client receiving the error message is prompted to reconnect. Associate with other access points using the communication method.

[0086] The present invention is not limited to each of the above embodiments, and can be variously modified at the implementation stage without departing from the gist thereof. In addition, each embodiment may be carried out in combination as appropriate as possible, in which case the combined effects can be obtained. Further, each of the above embodiments includes inventions at various stages, and various inventions can be extracted by an appropriate combination of a plurality of disclosed constituent requirements. For example, when an invention is extracted by omitting some constituent requirements from all the constituent requirements shown in the embodiment, the omitted portion is appropriately supplemented by a well-known conventional technique when the extracted invention is carried out. It is something that is said.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a relay device and a communication system capable of effectively utilizing the band.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a wireless LAN system according to a first embodiment of the present invention.

FIG. 2 is a functional block diagram of an access point 1 according to the first embodiment of the present invention.

FIG. 3 is a flowchart for explaining the operation of the wireless LAN access point according to the first embodiment of the present invention.

FIG. 4 is a flowchart for explaining the operation of the wireless LAN access point according to the first embodiment of the present invention.

FIG. 5 is a flowchart for explaining the operation of the wireless LAN client.

FIG. 6 is a functional block diagram of an access point in a wireless LAN system according to a second embodiment of the present invention.

FIG. 7 is a flowchart for explaining the operation of the wireless LAN system according to the second embodiment of the present invention.

FIG. 8 is a flowchart showing the operation of a client of the wireless LAN system of the present invention.

[Description of code] 1 ... Wireless LAN access point, 2a ~ 2e ... Client, 11 ... Communication interface, 12 ... Relay unit, 13 ... Control unit, 14 ... Memory, 15 ... LAN interface, 21 ... LAN, 31 ... Communication unit, 31a ... IEEE802.11a communication unit, 31b ... IEEE802.11b communication unit, 32 ... Traffic detection unit, 33. .. Association request rejection unit, 34 ... Message transmission unit, 35 ... Association unit, 41 ... Communication unit, 42 ... Traffic detection unit, 43 ... Electric field strength measurement unit, 44 .. .Communication time measurement unit, 45 ... table, 46 ... client selection unit, 47 ... association unit, 48 ... message transmission unit, 49 ... wireless connection blocking unit.