JP5211968B2 - Access point, wireless connection method, and wireless communication system - Google Patents

Description

  The present invention reduces unevenness in the number of connected wireless terminals (hereinafter also simply referred to as “terminals”) for each access point in a wireless communication system having a plurality of access points, and equalizes the load on each access point. Regarding technology.

In general, in an environment of a wireless communication system (such as a wireless LAN (Local Area Network) system), a terminal selects an access point to perform connection. At this time, the terminal, for example, selects an access point with good communication quality among peripheral access points, that is, an access point with the strongest radio wave intensity to establish a connection (see Patent Document 1).
JP 2000-101596 A

  However, in the prior art including Patent Document 1, it is the terminal side that determines the connection pair of the terminal and the access point, and only the radio wave intensity from the access point determines the connection destination. When viewed from the whole, there is often a bias in the number of terminals connected to the access point.

  FIG. 8 is an explanatory diagram of an example in which the number of terminals connected to the access point is biased. In this example, access points 11, 12, and 13 (collectively referred to as “access point 10”) are connected to the network 30 by a wired LAN. In areas 41, 42 and 43 (collectively referred to as “area 40”), each access point 10 accesses from wireless LAN terminals 21, 22 and 23 (collectively referred to as “wireless LAN terminal 20”). This is an area (wireless communicable area) that can accept.

Connection from the wireless LAN terminal 20 to the access point 10 is performed according to the following procedure.
(1) The wireless LAN terminal 20 transmits a Probe request command to the surroundings as a broadcast in order to search for connectable access points 10.
(2) Upon receiving this Probe request command, the access point 10 transmits a Probe response to the wireless LAN terminal 20.
(3) Upon receiving this Probe response, the wireless LAN terminal 20 selects the access point 10 having the strongest reception strength and performs connection processing.

  In the example of FIG. 8, when the reception strength of the Probe response response from the access point 11 is the strongest, the wireless LAN terminal 21 performs a connection process to the access point 11. Similarly, the wireless LAN terminal 22 and the wireless LAN terminal 23 also perform connection processing to the access point 11 when the reception strength of the Probe response response from the access point 11 is the strongest. That is, connections are concentrated on the access point 11. As described above, when connections from many wireless LAN terminals 20 are concentrated on a specific access point 10, the processing load on the access point 10 increases, causing problems such as a decrease in data transfer throughput.

  Therefore, the present invention has been made to solve the above-described problem, and it is an object of the present invention to reduce the uneven number of connected wireless terminals for each access point and to level the load on each access point.

In order to solve the above-described problems, the present invention provides an access point that is communicably connected to another access point having a partially overlapping wireless communication area, and to which a wireless terminal is wirelessly connected. A storage unit that stores a first number that is the number of wireless terminals to which an access point is wirelessly connected, a wireless communication area of the other access point, and a wireless communication area of the other access point When a connection request having the address information of the other access point is received from the new wireless terminal existing inside the wireless terminal, the wireless device communicates with the other access point and wirelessly connects to the other access point. get the second number is the number of terminals, compared with the second number related to the other access point, and the first number, the A processing unit that, when the number of 1 is larger, determines that the connection with the new wireless terminal is rejected, and transmits a response signal of the rejection to the new wireless terminal, To do.

In other words, when a connection request is received from a wireless terminal, the access point compares the number of wireless terminals connected to the other access point and the wireless access area that partially overlaps the wireless communication coverage area. If so, refuse the connection. As a result, it is possible to reduce the bias in the number of connected wireless terminals for each access point, and to level the load on each access point.
Other means will be described later.

  ADVANTAGE OF THE INVENTION According to this invention, the bias | inclination of the number of connection of the radio | wireless terminal for every access point can be reduced, and the load of each access point can be equalized.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described with reference to the drawings (refer to drawings other than the referenced drawings as appropriate). FIG. 1 is an overall configuration diagram showing a wireless LAN system of this embodiment. In the present embodiment, a case where handover control is performed on a wireless LAN terminal will be described.

  As shown in FIG. 1, a wireless LAN system (wireless communication system) S is configured to include access points 11, 12, and 13 (collectively referred to as "access point 10"). Each access point 10 is connected to the network 30 by wire. Areas 41, 42, and 43 (collectively referred to as "area 40") are referred to as wireless LAN terminals (wireless terminals) 21, 22, and 23 (collectively referred to as "wireless LAN terminals 20"). ) Is an area that can accept access from. Each area 40 partially overlaps. Each wireless LAN terminal 20 is assumed to exist in the overlapping portion of the area 40. Further, hereinafter, the network 30 is also referred to as “wired LAN”, and the area 40 capable of wireless communication is also referred to as “wireless LAN”.

  FIG. 2 is a configuration diagram of the access point. The access point 10 is a communication device configured to include a wired LAN transmission / reception control unit 101, a wireless LAN transmission / reception control unit 102, an access point connection processing unit 103, and a connection rejection terminal table 104.

The wired LAN transmission / reception control unit 101 controls the wired LAN, transmits data on the wired LAN, and receives data flowing on the wired LAN.
The wireless LAN transmission / reception control unit 102 controls the wireless LAN, transmits data on the wireless LAN, and receives data flowing on the wireless LAN. The wireless LAN transmission / reception control unit 102 can perform wireless transmission / reception of signals using a wireless standard such as IEEE (The Institute of Electrical and Electronics Engineers) 802.11, for example.

When the access point connection processing unit 103 receives a connection request (signal) from the wireless LAN terminal 20 via the wireless LAN transmission / reception control unit 102, the access point connection processing unit 103 communicates with the handover source access point 10 via the wired LAN transmission / reception control unit 101. Communication is performed, and permission / denial of connection of the wireless LAN terminal 20 is determined. The access point connection processing unit 103 is realized by, for example, a CPU (Central Processing Unit) and a RAM (Random Access Memory).
The connection rejection terminal table 104 is a table for storing a list of wireless LAN terminals 20 whose connection is rejected. The connection rejection terminal table 104 is stored, for example, in a storage unit (not shown) such as an HDD (Hard Disk Drive) or a RAM (Random Access Memory).

  The access point 10 includes a beacon signal transmission function for controlling the wireless LAN terminal 20 in addition to the above, but illustration and description of those that are not directly related to the features of the present invention are omitted. To do.

  Next, the operation of each device in the wireless LAN system S will be described. As a major flow, first, the wireless LAN terminal 20 transmits a Probe request command (a type of connection request) as a broadcast to search for a connectable access point 10 (operation 1). Next, the access point 10 that has received the Probe request command transmits a Probe response to the wireless LAN terminal 20 (Operation 2). After that, the wireless LAN terminal 20 that has received the Probe response response from one or more access points 10 selects the access point 10 having the strongest reception strength and transmits a connection request (Resociation) to the access point 10 (operation) 3). In the following, for convenience of explanation, first, the operation 3 will be described with reference to FIG. 3, and then the operation 1 and the operation 2 will be described with reference to FIG.

FIG. 3 is a flowchart when the access point receives a connection request (Reassociation) from the wireless LAN terminal.
The access point connection processing unit 103 of the access point 10 that has received the connection request (Resociation) from the wireless LAN terminal 20 transmits the wireless LAN terminal 20 to the handover source access point 10 stored in the connection request (Resociation) packet. The number of connected devices (hereinafter also simply referred to as “number of connected devices”) is inquired (step S31).

  Here, FIG. 5 shows a format of a connection request (Reassociation) packet defined by IEEE 802.11. “Current AP address” in this format is the address of the access point 10 that is the handover source. By using this address, it is possible to make an inquiry about the number of connections to the access point 10 that is the handover source. The abbreviations in this format will be described. “DA” represents “Destination Address (destination address)”, “SA” represents “Source Address (source address)”, and “BSS ID” represents “Basic Service”. “Set Identifiers”, and “SSID” represents “Service Set Identifiers”. Explanations other than abbreviations are omitted.

Returning to FIG. 3 and continuing the description, after step S31, the access point connection processing unit 103 determines that the number of connected access points 10 (second number) that is the source of handover (HO) is the current number of the access point 10 itself. It is determined whether the number is greater than the number of connected devices (first number) (step S32).
In the case of Yes in step S32, the access point connection processing unit 103 transmits a connection request permission response to the wireless LAN terminal 20 (step S33).

  If No in step S32, the access point connection processing unit 103 records the MAC (Media Access Control) address of the wireless LAN terminal 20 and the current time (rejection time) in the connection rejection terminal table 104 (step S34). . Here, FIG. 6 is a diagram illustrating an example of a format of the connection rejection terminal table. As shown in FIG. 6, the connection rejection terminal table 104 can store the MAC address 601 of the wireless LAN terminal and the corresponding rejection time 602 information.

  Returning to FIG. 3 and continuing the description, after step S34, the access point connection processing unit 103 transmits a connection rejection response (response signal) to the wireless LAN terminal 20 (step S35).

  With this process, when there is a connection request from the wireless LAN terminal 20, the access point 10 has a larger number of connected access points 10 than the adjacent (handover source) access point 10 (the load is increased). When it is high), you can refuse the connection. That is, it is possible to reduce the unevenness in the number of connected wireless LAN terminals 20 for each access point 10 and to level the load on each access point 10.

  When the access point 10 transmits a connection rejection response to the wireless LAN terminal 20, the wireless LAN terminal 20 again transmits a Probe request command to the surrounding area to attempt connection. In this case, it is efficient in terms of information processing that the access point 10 ignores the Probe request command for a predetermined time from the rejection of the connection. Processing in that case will be described with reference to FIG.

FIG. 4 is a flowchart when the access point receives a Probe request command from the wireless LAN terminal.
The access point connection processing unit 103 of the access point 10 that has received the Probe request command from the wireless LAN terminal 20 searches whether the MAC address of the wireless LAN terminal 20 exists in the connection rejection terminal table 104 (step S41).

  If there is no MAC address of the wireless LAN terminal 20 in the connection rejection terminal table 104 (No in step S41), the access point connection processing unit 103 transmits a Probe response response to the wireless LAN terminal 20 (step S42). .

  When the MAC address of the wireless LAN terminal 20 is present in the connection rejection terminal table 104 (Yes in step S41), the access point connection processing unit 103 refers to the rejection time 602 in the connection rejection terminal table 104 and starts from the recording time. It is determined whether or not the time length up to the current time is equal to or longer than the set time (step S43). This set time indicates the duration when the access point 10 refuses connection, and an appropriate value (several seconds to several minutes) is set in advance by the user.

  In the case of Yes in step S43, the access point connection processing unit 103 deletes the MAC address and rejection time (time) of the wireless LAN terminal 20 from the connection rejection terminal table 104 (step S44), and the wireless LAN terminal 20 A Probe response is transmitted (step S45).

  In the case of No in step S43, the access point connection processing unit 103 does not transmit a Probe response response because it can be determined that this Probe request is a retry once it has been disconnected (Step S46). In other words, the access point 10 ignores the Probe request within the set time from the rejection time, so that the wireless LAN terminal 20 cannot recognize the access point 10. Thereby, useless processing of the access point 10 and the wireless LAN terminal 20 can be avoided.

  As described above, according to the access point 10 in the wireless LAN system S of the present embodiment, the access at the handover source is performed at the timing when the wireless LAN terminal 20 performs handover (timing when the access point 10 receives a connection request (Resociation)). The number of connections between the point 10 and its own access point 10 is compared. If the number of connections of the own access point 10 is larger, the connection of the wireless LAN terminal 20 is rejected. As a result, it is possible to reduce the unevenness of the number of connected wireless LAN terminals 20 for each access point 10 and to level the load on each access point 10.

  FIG. 7 is an overall configuration diagram showing a wireless LAN system when the load of each access point is leveled. Unlike the case of FIG. 8 where the load is concentrated on the access point 11, in the wireless LAN system S of FIG. 7, the wireless LAN terminal 21 is connected to the access point 11, the wireless LAN terminal 22 is connected to the access point 12, By connecting the wireless LAN terminal 23 to the access point 13, the load on each access point 10 is leveled.

  Further, according to the access point 10 in the wireless LAN system S of the present embodiment, when the wireless LAN terminal 20 is handed over, it is more appropriate to compare the number of connection between the access point 10 that is the handover source and its own access point 10 It is possible to make a determination regarding connection refusal of the wireless LAN terminal 20 at an appropriate timing.

  Further, the access point 10 and the wireless LAN terminal are ignored by ignoring the probe request of the same wireless LAN terminal 20 within a predetermined setting time after the access point 10 determines that the connection with the wireless LAN terminal 20 is rejected. Twenty unnecessary processes can be avoided.

Although description of this embodiment is finished above, the aspect of the present invention is not limited to these.
For example, the timing for comparing the number of connected access points 10 is not limited to when the wireless LAN terminal 20 is handed over, but issues a connection request when the wireless LAN terminal 20 can communicate with the plurality of access points 10. Any time.
In addition, specific configurations such as hardware and flowcharts can be appropriately changed without departing from the spirit of the present invention.

1 is an overall configuration diagram showing a wireless LAN system of an embodiment. It is a block diagram of an access point. 6 is a flowchart when an access point receives a connection request from a wireless LAN terminal. 10 is a flowchart when the access point receives a Probe request command from a wireless LAN terminal. This is a format of a connection request packet defined by IEEE 802.11. It is a figure which shows an example of a format of a connection rejection terminal table. It is a whole block diagram which shows the wireless LAN system at the time of equalizing the load of each access point. It is explanatory drawing of the example in which the deviation has generate | occur | produced in the number of terminals connected to the access point.

Explanation of symbols

10, 11, 12, 13 Access point 20, 21, 22, 23 Wireless LAN terminal 30 Network 40, 41, 42, 43 Area 101 Wired LAN transmission / reception control unit 102 Wireless LAN transmission / reception control unit 103 Access point connection processing unit 104 Connection rejection Terminal table S Wireless LAN system

Claims (7)

An access point that is communicably connected to another access point with a partially overlapping wireless communication area, and to which a wireless terminal is wirelessly connected,
A storage unit that stores a first number that is the number of the wireless terminals to which the access point is wirelessly connected;
A connection request having address information of the other access point is received from a new wireless terminal that exists in the wireless communication area of the own access point and in the wireless communication area of the other access point. A second number that is the number of the wireless terminals that communicate with the other access point and wirelessly connect to the other access point, and the second number related to the other access point; The first number is compared, and when the first number is larger, it is determined that the connection with the new wireless terminal is rejected, and the rejection response signal is sent to the new wireless terminal. A processing unit to transmit;
An access point comprising:   The processing unit receives the connection request when the new wireless terminal is handed over from the other access point to its own access point, and compares the second number with the first number. The access point according to claim 1. The storage unit stores a predetermined set time,
The processing unit does not return a response signal even if a connection request is received from the new wireless terminal within the predetermined set time after determining that the connection with the new wireless terminal is rejected. The access point according to claim 1 or claim 2. A wireless connection method using an access point that is wirelessly connected to a wireless terminal and that is communicably connected to another access point with a partially overlapping wireless communication area ,
The access point includes a storage unit that stores a first number that is the number of the wireless terminals to which the access point is wirelessly connected, and a processing unit.
The processing unit has the address information of the other access point from the new wireless terminal that exists in the wireless communication area of its own access point and in the wireless communication area of the other access point. When the connection request is received, the second access number is obtained by communicating with the other access point and the other access point is wirelessly connected to the other access point , and the second number related to the other access point is obtained . 2 is compared with the first number. When the first number is larger, it is determined that the connection with the new wireless terminal is rejected, and the rejection response signal is A wireless connection method comprising: transmitting to the wireless terminal.   The processing unit receives the connection request when the new wireless terminal is handed over from the other access point to its own access point, and compares the second number with the first number. The wireless connection method according to claim 4. The storage unit stores a predetermined set time,
The processing unit does not return a response signal even if a connection request is received from the new wireless terminal within the predetermined set time after determining that the connection with the new wireless terminal is rejected. The wireless connection method according to claim 4 or 5. A wireless communication system comprising a plurality of access points to which wireless terminals are wirelessly connected so as to be able to communicate with each other,
The access point is
The wireless communication area of your own access point partially overlaps with the wireless communication area of other access points.
A storage unit that stores a first number that is the number of the wireless terminals to which the access point is wirelessly connected;
A connection request having address information of the other access point is received from a new wireless terminal that exists in the wireless communication area of the own access point and in the wireless communication area of the other access point. A second number that is the number of the wireless terminals that communicate with the other access point and wirelessly connect to the other access point, and the second number related to the other access point; The first number is compared, and when the first number is larger, it is determined that the connection with the new wireless terminal is rejected, and the rejection response signal is sent to the new wireless terminal. A processing unit to transmit;
A wireless communication system comprising:

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