JP2004201006A - Multiple access point control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, when access points have been already connected by the stipulated number of stations in the conventional wireless communication systems, connections of the stations connectable to the access points cannot be established and at the same time redundant electric power consumption is generated in superfluous occupation of frequency channels and APs. <P>SOLUTION: There is provided a control method for controlling multiple access points connectable to multiple stations. In the control method, the multiple access points are initiated according to predetermined initiation priority to connect sequentially the stations to the initiated access points. Consequently, improvement in functions of communication systems, efficient use of communication media, and electric power saving can be realized. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to controlling a plurality of access points in a wireless communication system.
[0002]
[Prior art]
In a wireless LAN system, a technique for limiting the number of stations connected to an access point has been proposed.
[0003]
FIG. 1 shows a configuration example of a wireless LAN system including a plurality of access points (hereinafter abbreviated as AP) connected to a wired LAN and a plurality of stations (hereinafter abbreviated as STAs).
[0004]
In FIG. 1, reference numeral 100 denotes a wired LAN, A101 to D101 connected to the wired LAN 100 are AP1 to AP4, respectively, and A103 to G103 communicating with AP1 to AP4 are STA1 to STA7, respectively. Further, circles indicated by A102 to D102 indicate communication ranges of AP1 (A101) to AP4 (D104), respectively (for example, A102 is a communication range of AP1 (A101)).
[0005]
Further, each AP has a storage unit for storing its own identifier, and each STA has a storage unit for storing the identifier of the AP to which it is connected. Here, it is assumed that the AP stores “ID-1” as its own identifier and the STA stores “ID-2” as the identifier of the AP to be connected.
[0006]
When the STA enters a range in which it can communicate with the AP due to movement or power-on, the STA transitions between authentication (authentication) and association (association) states and connects to the AP.
[0007]
As an example, FIG. 2 shows a sequence until the STA1 and the AP1 transition to the communication state according to the IEEE802.11b standard. In the following, with reference to FIG. 2, a procedure until STA1 and AP1 are connected in the wireless LAN system will be described, and a technique for limiting the number of STAs connected to AP1 will be described.
[0008]
First, when STA1 receives the broadcast signal transmitted by AP1 (201), STA1 compares the stored identifier ID-2 of AP1 to be connected and the identifier ID-1 of AP1 included in the received broadcast signal. Compare. If "ID-1" and "ID-2" are the same, STA1 transmits an authentication permission request signal to AP1 (202) and performs authentication processing (203).
[0009]
The authentication process (203) includes two types of authentication methods, open authentication and shared key authentication. In particular, shared key authentication is performed only under the condition that STA1 and AP1 hold the same shared key. success.
[0010]
When the authentication is successful, AP1 transmits an authentication request permission response (= success) to STA1 (204). If the authentication request permission response received by STA1 is “success”, STA1 and AP1 transition to an authentication state (205).
[0011]
Subsequently, STA1 issues an association request to AP1 (206), and AP1 transmits an association request response (= success) to STA1 (207). If the association request response is “success”, the STA1 and the AP1 transition to the association state (208) and enter the connection state.
[0012]
The procedure up to the connection between the STA and the AP in the conventional wireless LAN has been described above.
[0013]
In addition, in the above-described conventional wireless LAN system, there is a technique for limiting the number of STAs connected to an AP (see Patent Document 1). This is because, in a wireless LAN system having a plurality of APs, when a STA in a service area managed by an arbitrary AP issues a connection request to the AP in excess of a predetermined number, the connection of the STA is performed. Is limited.
[0014]
[Patent Document 1]
JP-A-11-55286
[Problems to be solved by the invention]
However, when controlling the number of STAs connected to an AP in a wireless LAN system in which communication ranges of a plurality of APs overlap each other as shown in FIG. Although the authenticated STA in the authentication state (209) is within the communication range of the plurality of APs, and the total number of connectable STAs of the plurality of APs as a whole is equal to or less than the specified value, Since the number of STAs connected to the AP in the authentication state with the STA exceeds a prescribed value, there is a problem that the AP cannot be connected to the AP.
[0016]
That is, even if an STA can communicate with a plurality of APs, the number of APs that can be authenticated is limited, so even if other APs have free space, the connection is rejected and the number of STAs connected to the APs that can be authenticated is defined. Unless the value falls below, a connection with the AP cannot be established. This will be described more specifically below.
[0017]
In FIG. 1, STA1 (A103) changes STA3 (C103) to AP1 (A101), STA4 (D103) changes to AP2 (B101), STA5 (E103) changes to AP3 (C101), and STA6 (F103) changes to AP4 (D101). ). Here, the specified value of the STA that can be connected to each AP is 3.
[0018]
Here, it is assumed that the STA 7 (G103) having the identifier of the AP1 as an identifier required for connection to the AP newly requests the AP1 (A101) to connect to the AP1 (A101) in accordance with the sequence of FIG. I do.
[0019]
Even if the STA 7 (G103) succeeds in the authentication process (203) (204) and enters the authentication state (205), the number of STAs connected to the AP1 (A101) has reached the specified value 3. , AP1 (A101) rejects the STA7 (103) with a request to start communication.
[0020]
As a result, STA7 (G103) is an authenticated STA in the authentication state (209), within the communication range from AP1 (A101) to AP4 (D101), and from AP1 (A101) to AP4 (D101). Despite the fact that the number of STAs connected to the whole “6” is equal to or less than the specified value “12 (3 × 4)” of the total number of STAs connectable from AP1 (A101) to AP4 (D101), connection with other APs AP2 (B101) cannot be connected to AP4 (D101) because there is no identifier for the connection.
[0021]
In addition, if the STAs limit the APs that can be connected as described above, since a plurality of STAs are connected to each AP at random and perform communication, occupation of an extra frequency channel and extra power in the AP Consumption is occurring. Specifically, in FIG. 1, the total number of STAs connected to the AP is six. Since the prescribed value of the number of STAs connected to each AP is three, four APs need to be processed by two APs (three in consideration of the connection of STA7 (G103)). It is up and occupying extra frequency channels and extra power consumption at the AP.
[0022]
[Means for Solving the Problems]
The present invention for solving the above problems is a control method for controlling a plurality of access points to which a plurality of stations can be connected, wherein the plurality of stations can connect to the plurality of access points. Assigning determination information for determination to the plurality of access points, activating the plurality of access points according to a predetermined activation order, and the activated access point transmits a signal including the determination information to at least one of the plurality of stations. Transmitting to any of the activated stations from the plurality of stations until the number of stations connected to the activated access point matches the number of stations connectable to the activated access point. A connection request according to the transmission to the access point, Characterized in that letting accepted dynamic access point.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention relates to control processing of a plurality of access points to which a plurality of stations can be connected, and in particular, determination information for determining that a plurality of stations can connect to a plurality of access points is provided for each of a plurality of access points. Assigned, the plurality of access points are activated in accordance with a predetermined activation order, the activated access point transmits a signal including determination information to at least one of the plurality of stations, and is connected to the activated access point. Until the number of stations matches the number of stations that can be connected to the activated access point, the activated access point accepts a connection request in response to transmission to the activated access point from any of the plurality of stations. It is characterized by the following.
[0024]
The present invention can be realized as an apparatus, a method, a program, or a storage medium for storing the program in the configuration and processing shown in the drawings attached to the application, corresponding to the following embodiments.
[0025]
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0026]
[First Embodiment]
First, FIGS. 4A to 4D are diagrams showing configuration examples of a wireless LAN system capable of implementing the present invention. 4A to 4D, reference numeral 400 denotes a multi-function access point (hereinafter, abbreviated as MFAP), which integrally includes four APs, AP1 (A401) to AP4 (D401). Circles from A402 to D402 indicate communication ranges from AP1 (A401) to AP4 (D401), respectively. STA1 (A403) to STA7 (G403) (hereinafter, these STAs are abbreviated as STA403) are located in a portion where the communication ranges from A402 to D402 overlap.
[0027]
FIG. 5 is a diagram illustrating an example of the configuration of the MFAP 400. The MFAP 400 is connected to the MFAP control unit 501, similarly to the MFAP control unit 501, the APs AP1 (A503) to AP4 (D503) connected to the MFAP control unit 501, and similarly connected to the MFAP control unit 501. And an AP information storage table 502 for managing information on the AP. An example of the AP information stored in the AP information storage table 502 is as shown in FIGS.
[0028]
In FIG. 7, reference numeral 701 denotes an activation order of AP1 (A404) to AP4 (D404), 702 denotes an AP identifier provided for identifying each AP, and 703 denotes an STA of an STA connectable to each AP. 704 indicates the number of STAs actually connected to each AP (the number of connected STAs), and 705 indicates the current state of each AP (that is, whether the AP is stopped, Or has been activated).
[0029]
Next, an example of the configuration of the STA 403 in the present invention will be described with reference to FIG. In the present invention, the STA 403 includes a wireless unit 601 for communicating with the AP, a control unit 602 for controlling the operation of the STA 403, and an AP identifier storage table 603 for managing information about the AP to which the STA 403 connects. .
[0030]
The AP identifier storage table 603 is a table that stores identifiers of a plurality of APs provided in the MFAP 400. In the embodiment of the present invention, the AP identifier storage table 603 stores identifiers of AP1 (A503) to AP4 (D503) in FIG. I have. Further, in the AP identifier storage table 603, the identifier does not have information relating to the priority such as the connection order.
[0031]
Next, the contents of the processing in the MFAP 400 in the present embodiment will be described. The MFAP 400 controls the APs to which the STA 403 can connect by controlling the operation states of AP1 (A503) to AP4 (D503) as shown in FIGS. 4A to 4D.
[0032]
Based on the control in the MFAP 400, the operation in the present invention from the STA1 (A403) to the STA7 (G403) connecting to a predetermined AP will be described with reference to FIGS. 2, 3, 4, 8, and 9. explain. FIG. 3 is a flowchart of the process in the STA 403 in the present embodiment. FIG. 8 is a diagram showing a processing sequence in the present embodiment. FIG. 9 is a flowchart of a process in the MFAP control unit 501 in the present embodiment.
[0033]
First, FIG. 4A is a diagram illustrating an initial state of the wireless LAN system according to the present embodiment. Here, all the APs 1 to 4 in the MFAP 400 are in a stopped state. The contents of the AP information storage table 502 of the MFAP 400 corresponding to this state are as shown in FIG.
[0034]
Referring to FIG. 7A, the starting order 701 in which the MFAP control unit 501 starts the AP is in the order of AP1 (A401), AP2 (B401), AP3 (C401), AP4 (D401), and AP1 (A401). , AP2 (B401), AP3 (C401), and AP4 (D401) have AP identifiers 702 of AP1, AP2, AP3, and AP4, respectively. The specified value 703 of the STA connected to each AP is 3, and the number of connected STAs 704 is 0, that is, STA1 (A403) to STA7 (G403) are not connected to any AP, and State 705 is in a stopped state.
[0035]
When the MFAP (400) starts operating from such an initial state, the MFAP control unit 501 first turns on the power to the AP1 (A401) according to the start order 701 of the AP information storage table 502 (801, S901). This activates AP1, and AP1 (A401) transmits a broadcast signal.
[0036]
When the STA1 (A403) receives the broadcast signal transmitted by the AP1 (A401) (802, S301), the identifier of the AP1 included in the broadcast signal and the plurality of APs stored in the STA1 AP identifier storage table 603. The identifiers (AP1 to AP4 in this embodiment) are compared (S302), and if the identifier of AP1 included in the broadcast signal received from AP1 is stored in the AP identifier storage table 603, the broadcast signal An authentication permission request signal is transmitted to the source AP (202, S303). The AP identifiers stored in the AP identifier storage table 603 according to the present embodiment do not have a priority such as a connection order, and sequentially issue an authentication permission request to the transmission source APs of the broadcast signals received in 201 and S301. .
[0037]
The AP 1 performs an authentication process (203). As described above, this authentication processing (203) includes two types of authentication methods, open authentication and shared key authentication. In particular, shared key authentication is based on the condition that STA1 and AP1 hold the same shared key. Authentication succeeds only below. When the authentication is successful, AP1 transmits an authentication request permission response (= success) to STA1 (204). If the authentication request permission response received by STA1 is “success”, STA1 and AP1 transition to an authentication state (205, S304).
[0038]
STA1 further issues an association request to AP1 (206, S305), and AP1 transmits an association request response (= success) to STA1 (207). If the association request response is “success”, the STA1 and the AP1 transition to the association state (208) and enter the connection state.
[0039]
Based on the above sequence, the STA1 connects to the AP1 (803), and the AP1 (A401) transmits the STA connection information, which is information for notifying the MFAP control unit 501 that the connection with the STA has been established, to the MFAP. It is transmitted to the control unit 501. Upon acquiring the STA connection information (804), the MFAP control unit 501 updates the AP information storage table 502 (S903), and stores the specified number of connected STAs (703) and the number of connected STAs (704) in the AP information storage table 502. A comparison is made (S904).
[0040]
The MFAP control unit 501 repeats the processing from S902 to S904 based on the comparison result in S904 until the number of connected STAs reaches a specified value.
[0041]
STA2 (B403) and STA3 (C403) are also connected to AP1 (A401) in the same manner as STA1 (A403). The contents of the AP information storage table 502 immediately after the STA2 (B403) and the STA3 (C403) are connected to the AP1 (A401) are as shown in FIG. 7B.
[0042]
Referring to FIG. 7B, since the number of connected STAs (704) of AP1 (A401) has reached the specified number of connected STAs (703), the MFAP control unit 501 sets the STA connection rejection setting to AP1 (A401). Performing (804, S905), if there is an AP in the stopped state in all the APs (S906), the power is turned on to the AP having the highest start order 701 among the APs in the stopped state, in this case, AP2 (B401) ( 806, S907). FIG. 4B shows the state of the wireless LAN system of the present invention immediately after the power is turned on to AP2 (B401). As described above, in the present embodiment, activation of a plurality of access points is performed by activating the next access point based on the activation order after the number of connected stations matches the number of connectable stations in the already activated access points. It is done by doing.
[0043]
As shown in FIG. 4B, since AP1 (A401) and AP2 (B401) are activated, STA4 (D401) can receive broadcast signals from two APs, AP1 (A401) and AP2 (B401). . In this embodiment, it is assumed that a broadcast signal is received in the order of AP1 (A401) and AP2 (B401).
[0044]
Upon receiving the broadcast signal of AP1 (A401) (807), STA4 (D403) transits to the authentication state based on FIG. 2 (202 to 206) and FIG. 3 (S301 to S305) (808). , An association request is made (809). However, since STA connection request rejection setting is made for AP1 (A401) by MFAP control section 501 (805), AP1 responds to STA4 (D403) with an association request response (= request rejection). ) Is transmitted (810). This sequence is an AP-STA connection failure sequence indicated by a broken line 815.
[0045]
Therefore, upon receiving the broadcast signal transmitted by AP2 (B401) (811), STA4 (D403) connects to AP2 (B401) based on FIG. 2 (202 to 208) (812), and MFAP control section 501 STA connection information is acquired from AP2 (B401) (813). This sequence is the AP-STA connection success sequence shown in the broken line of 814.
[0046]
STA5 (E403) and STA6 (F403) can receive broadcast signals from AP1 (A401) and AP2 (B401) in the same manner as STA4 (D403), and receive the broadcast signals from AP1 (A401). It operates based on the AP-STA connection failure sequence (815), and upon receiving a broadcast signal from AP2 (B401), operates based on the AP-STA connection success sequence (814).
[0047]
FIG. 7C shows the contents of the AP information storage table 502 of the MFAP (400) immediately after the STA6 (F403) has connected to the AP2 (B401).
[0048]
Referring to FIG. 7C, since the number of connected STAs 704 of AP2 (B401) has reached the specified number of connected STAs 703, the MFAP control unit 501 performs STA connection rejection setting for AP2 (B401) (S905). If there is any stopped AP among all the APs (S906), the power is turned on to the AP having the highest startup order 701 among the stopped APs, in this case, AP3 (C401) (S907). FIG. 4C shows a state of the wireless LAN system of the present invention immediately after power is supplied to AP3 (C401).
[0049]
As shown in FIG. 4C, since AP3 (C401) is activated from AP1 (A401), STA7 can receive three broadcast signals transmitted from AP1 (A401) to AP3 (C401).
[0050]
First, upon receiving the broadcast signals from AP1 (A401) and AP2 (B401), the STA 7 operates based on the AP-STA connection failure sequence (815). On the other hand, upon receiving the broadcast signal from the AP3 (C401), it operates based on the AP-STA connection success sequence (814), and connects to the AP3 (C401).
[0051]
FIG. 7D shows the contents of the AP information storage table 502 of the MFAP 400 immediately after the connection between the STA 7 (F403) and the AP 3 (C401), and FIG. 4D shows the state of the wireless LAN system of the present invention in the same state.
[0052]
As can be understood by comparing FIG. 1 with FIG. 4d, the implementation of the present invention enables the STA 7 (G403) to connect to the AP, and one of the four activated APs in FIG. By bringing the stand into a stopped state, effective use of the wireless medium and power saving can be realized.
[0053]
In the present embodiment described above, the means for starting the AP is powered on to the AP. However, it may be possible to supply a clock signal to the AP.
[0054]
In the above-described embodiment, AP1 to AP4 are provided as identifiers for identifying each AP from AP1 (A401) to AP4 (D401), and the identifiers are stored in the AP identifier storage table 603 of the STA. . That is, the identifiers of all connectable APs are stored as the determination information for determining the connectable APs by the STA 403. The determination information for determining a connectable AP is not limited to this, and may be, for example, information common to all the APs to which the STA 403 can connect and the STA 403.
[0055]
For example, AP1 (A401) to AP4 (D401) can store “0101” as determination information in addition to the contents of the AP information storage table 502 shown in FIG. Information “0101” can be stored. The broadcast signal transmitted from AP1 (A401) to AP4 (D401) includes, in addition to the identifier for identifying the AP, determination information (identifier, password or code) common to APs to which the STA can connect. STA 403 that stores the determination information, upon receiving the broadcast signal, determines whether or not the received broadcast signal includes the determination information stored therein, When the determination information is included, an authentication permission request can be made to the AP.
[0056]
As a result, as long as the STA has the predetermined determination information, even if a new AP is added, the new AP can be provided with the determination information without changing the STA setting. Connection can be established.
[0057]
As described above, according to the present embodiment, in a wireless LAN system in which the communication ranges of a plurality of APs overlap each other, as long as the total number of STAs connectable as a plurality of APs is equal to or less than a specified value, the plurality of If the STA can connect to any one of the plurality of APs, the STA can connect to any of the plurality of APs.
[0058]
In the present embodiment, a plurality of APs to which a plurality of STAs can be connected are sequentially activated based on a predetermined activation order, whereby a number of APs corresponding to the number of connected STAs can be operated. As a result, it is possible to suppress occupation of an extra frequency channel and extra power consumption in the AP.
[0059]
[Second embodiment]
In the first embodiment, the AP, the MFAP control unit 501, and the AP information storage table 502 are integrally configured, but in the present embodiment, the control device 1000 including the MFAP control unit 501 and the AP information storage table 502 However, a configuration as shown in FIG. 10 on the same communication medium as each AP (for example, a network such as a LAN) can be adopted.
[0060]
Reference numeral 1000 in FIG. 10 denotes a control device. AP1 (A1001) to AP4 (D1001) correspond to AP1 (A401) to AP4 (D401), A1002 to D1002 defining the communication range correspond to A402 to D402, and STA1. (A1003) to STA7 (G1003) correspond to STA1 (A403) to STA7 (G403).
[0061]
FIG. 11 shows the configuration of the control device 1000 according to the present embodiment. Reference numeral 1100 denotes a wired LAN, the control unit 1101 corresponds to the MFAP control unit 501, and the AP information storage table 1102 corresponds to the AP information storage table 502.
[0062]
In the above configuration, the same effects as those of the first embodiment can be obtained by replacing the MFAP control unit 501 in the sequence of FIG. 8 with the control unit 1101 and replacing the MFAP control unit 501 in the flow of FIG. 9 with the control unit 1101. Can be obtained.
[0063]
[Other embodiments]
Note that the present invention is applicable to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but is not limited to a single device (for example, a personal computer, a portable information terminal). , Mobile phones, etc.).
[0064]
Further, an object of the present invention is to supply a storage medium (or a recording medium) in which a program code of software for realizing the functions of the above-described embodiments is recorded to a system or an apparatus, and a computer (or a CPU or a CPU) of the system or the apparatus. Needless to say, the present invention can also be achieved by an MPU) reading and executing a program code stored in a storage medium. In this case, the program code itself read from the storage medium realizes the function of the above-described embodiment, and the storage medium storing the program code constitutes the present invention. When the computer executes the readout program code, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
[0065]
Further, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function of the program is performed based on the instruction of the program code. It goes without saying that the CPU included in the expansion card or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.
[0066]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the improvement of the function of a radio | wireless communications system, the efficient use of a radio | wireless medium, and realization of power saving become possible.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration example of a conventional wireless LAN system.
FIG. 2 is a diagram showing a connection sequence between an AP and a STA according to the present invention.
FIG. 3 is a flowchart of a process in an STA corresponding to the embodiment of the present invention.
FIG. 4a is a diagram showing a wireless LAN system according to the first embodiment of the present invention.
FIG. 4b is a diagram showing a wireless LAN system according to the first embodiment of the present invention.
FIG. 4c is a diagram showing a wireless LAN system according to the first embodiment of the present invention.
FIG. 4D is a diagram showing a wireless LAN system according to the first embodiment of the present invention.
FIG. 5 is a diagram illustrating an example of a configuration of an MFAP according to the first embodiment of the present invention.
FIG. 6 is a diagram illustrating an example of a configuration of an STA corresponding to the embodiment of the present invention.
FIG. 7 is a diagram showing an example of an AP information storage table corresponding to the embodiment of the present invention.
FIG. 8 is a diagram showing a connection sequence between the STA and the AP according to the embodiment of the present invention.
FIG. 9 is a flowchart of a process in MFAP according to the embodiment of the present invention.
FIG. 10 is a diagram illustrating an example of a configuration of a wireless LAN system according to a second embodiment of the present invention.
FIG. 11 is a diagram illustrating an example of a configuration of a control device according to a second embodiment of the present invention.

Claims (1)

A control method for controlling a plurality of access points to which a plurality of stations can be connected,
Assigning determination information for determining that the plurality of stations can connect to the plurality of access points to the plurality of access points,
Activating the plurality of access points according to a predetermined activation order, the activated access point transmits a signal including the determination information to at least one of the plurality of stations,
The transmission from any of the plurality of stations to the activated access point until the number of stations connected to the activated access point matches the number of stations connectable to the activated access point. A control method characterized by causing the activated access point to accept a connection request in response to the request.

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