Access point, wireless terminal control method, and program

Abstract

To provide an access point capable of assisting a wireless terminal in switching access points.SOLUTION: An access point includes an acquisition unit that acquires, from a wireless terminal connected to the access point, first quality data representing communication quality between the access point and the wireless terminal, and second quality data representing communication quality between another access point different from the access point and the wireless terminal, a determination unit that determines whether the wireless terminal should connect to the other access point rather than the access point based on the first quality data and the second quality data, and an output unit that outputs a switching command to prompt the wireless terminal to connect to the other access point when it is determined that the wireless terminal should connect to the other access point.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an access point, a control method for a wireless terminal, and a program. [Background technology]

[0002] Patent document 1 discloses a technology in which a client receives probe responses from multiple access points, and based on the communication quality during communication of each probe response, identifies the access point with the best communication quality for the client, and sends an authentication request. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4685923 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, many wireless terminals do not have the above-mentioned functions, but it would be convenient for such wireless terminals to be able to support switching of access points from the outside.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its main objective is to provide an access point, a control method for a wireless terminal, and a program capable of assisting a wireless terminal in switching access points. [Means for solving the problem]

[0006] In order to solve the above problem, an access point according to one aspect of the present invention includes an acquisition unit that acquires, from a wireless terminal connected to the access point, first quality data representing a communication quality between the access point and the wireless terminal and second quality data representing a communication quality between an access point other than the access point and the wireless terminal, a determination unit that determines whether the wireless terminal should be connected to the other access point rather than the access point based on the first quality data and the second quality data, and an output unit that outputs a switching command to the wireless terminal to prompt the wireless terminal to connect to the other access point when it is determined that the wireless terminal should be connected to the other access point. This makes it possible to support the wireless terminal in switching access points.

[0007] In the above aspect, the acquisition unit may further acquire at least one of first status data representing a communication congestion state of the access point and second status data representing a communication congestion state of the other access point, and the determination unit may determine whether or not to connect to the other access point based on at least one of the first status data and the second status data. This makes it possible to make a determination taking into account the communication congestion state.

[0008] In the above aspect, the first status data may include a channel usage rate in the access point, and the second status data may include a channel usage rate in the other access point. This makes it possible to make a decision taking into account the channel usage rate.

[0009] In the above aspect, the first status data may include the number of wireless terminals connected to the access point, and the second status data may include the number of wireless terminals connected to the other access point, which makes it possible to make a determination taking into account the number of connected wireless terminals.

[0010] In the above aspect, the determination unit may determine that a connection should be made to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a predetermined value to the value representing the communication quality between the access point and the wireless terminal. This makes it possible to prompt switching when the communication quality is good enough to a certain level.

[0011] In the above aspect, the determination unit may determine that a connection should be made to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a value corresponding to at least one of a channel usage rate of the access point and a channel usage rate of the other access point to the value representing the communication quality between the access point and the wireless terminal. This makes it possible to perform a determination taking into account the channel usage rate.

[0012] In the above aspect, the determination unit may determine that a connection should be made to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a value corresponding to at least one of the number of wireless terminals connected to the access point and the number of wireless terminals connected to the other access point to the value representing the communication quality between the access point and the wireless terminal. This makes it possible to perform a determination taking into account the number of connected wireless terminals.

[0013] In the above aspect, the determination unit may determine that a connection should be made to the other access point when a value representing a communication quality between the access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a value corresponding to at least one of a channel usage rate at the access point, a number of wireless terminals connected to the access point, and a channel usage rate at the other access point and a number of wireless terminals connected to the other access point to the value representing the communication quality between the access point and the wireless terminal. This makes it possible to perform a determination taking into account the channel usage rate and the number of wireless terminals.

[0014] In the above aspect, the access point may use one of a plurality of determination patterns for determining whether or not to connect to the other access point, and the other access point may use the same determination pattern as the one determination pattern. This makes it possible to prevent the access point from immediately reconnecting to the original access point after connecting to the other access point.

[0015] In the above aspect, the communication quality may be a received signal strength indicator (RSSI), which makes it possible to perform a determination based on the RSSI.

[0016] In the above aspect, the acquisition unit may acquire a plurality of the second quality data representing communication quality between the plurality of the other access points and the wireless terminal, and the determination unit may select one of the other access points to which the wireless terminal should connect based on the plurality of the second quality data. This makes it possible to select an access point suitable for connection.

[0017] In another aspect of the present invention, a method for controlling a wireless terminal includes obtaining, from a wireless terminal connected to a first access point, first quality data representing a communication quality between the first access point and the wireless terminal, and second quality data representing a communication quality between the wireless terminal and a second access point different from the first access point, determining whether the wireless terminal should connect to the second access point rather than the first access point based on the first quality data and the second quality data, and outputting a switching command to the wireless terminal to prompt the wireless terminal to connect to the second access point when it is determined that the wireless terminal should connect to the second access point. This makes it possible to support the wireless terminal in switching access points.

[0018] In addition, a program according to another aspect of the present invention causes a computer to execute the following steps: acquire first quality data indicating a communication quality between the first access point and the wireless terminal, acquired by the first access point from a wireless terminal connected to the first access point, and second quality data indicating a communication quality between the wireless terminal and a second access point other than the first access point, and determine whether the wireless terminal should be connected to the second access point rather than the first access point based on the first quality data and the second quality data. This makes it possible to support the wireless terminal in switching access points. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 illustrates an example of an access point control system. [Diagram 2] FIG. 2 illustrates an example of the configuration of an access point. [Diagram 3] FIG. 4 illustrates an example of the configuration of a control unit. [Figure 4] FIG. 11 is a diagram illustrating an example of a switching determination pattern. [Diagram 5] FIG. 13 is a diagram illustrating an example of an evaluation formula. [Figure 6] FIG. 11 is a diagram for explaining an example of switching of an access point. [Figure 7] FIG. 11 is a diagram for explaining an example of switching of an access point; [Figure 8] FIG. 11 is a diagram for explaining an example of switching of an access point; [Figure 9] FIG. 11 is a diagram for explaining an example of switching of an access point; [Figure 10] FIG. 11 is a diagram for explaining an example of switching of an access point. [Figure 11] FIG. 11 is a diagram for explaining an example of switching of an access point. [Figure 12] FIG. 11 is a diagram illustrating an example of a procedure of a control method for a wireless terminal. [Figure 13] FIG. 11 is a diagram illustrating an example of a procedure of a control method for a wireless terminal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given the same reference numerals, and detailed description thereof may be omitted as appropriate.

[0021] 1 is a diagram showing an example of an access point control system 100. The access point control system 100 includes a plurality of access points 1A to 1C. The access points 1A to 1C are installed in each room of a building, such as a school, a company, or a research facility.

[0022] The access points 1A to 1C are connected to a communication network N such as a wired LAN, and are capable of network communication with each other via the communication network N.

[0023] The access points 1A to 1C are wireless LAN access points, and the wireless terminal T is a wireless LAN client. The access points 1A to 1C provide the wireless terminal T with a connection to a communication network N.

[0024] The circles drawn with dashed lines in the figure represent radio wave coverage areas WA to WC that are reached by radio waves from the access points 1A to 1C. The access points 1A to 1C are placed at predetermined intervals so that the peripheral portions of the radio wave coverage areas WA to WC overlap with each other.

[0025] The access points 1A to 1C use different channels in the same frequency band (for example, the 5 GHz band) and use the same ESSID (Service Set Identifier).

[0026] The wireless terminal T is a portable wireless terminal such as a smartphone, a tablet computer, or a laptop computer, and is carried by a user.

[0027] The wireless terminal T stores in a memory setting data required for connecting to the access points 1A to 1C, such as the ESSID, MAC address, channel, encryption mode, and encryption key of the access points 1A to 1C.

[0028] The access point control system 100 may further include a network switch 7 connected to the communication network N, a router 8 provided at a higher level than the network switch, and a server 9 for controlling the access points 1A to 1C.

[0029] The specific configurations and operations of the access points 1A to 1C will be described below. In the following description, the access points 1A to 1C will also be collectively referred to as "access point 1."

[0030] 2 is a diagram showing an example of the configuration of the access point 1. The access point 1 includes a control unit 10, a wireless communication unit 11, and a wired communication unit 12.

[0031] The control unit 10 includes a computer including a CPU, RAM, ROM, non-volatile memory, an input / output interface, etc. The CPU of the control unit 10 executes information processing according to a program loaded from the ROM or non-volatile memory to the RAM.

[0032] The wireless communication unit 11 performs wireless communication using a wireless LAN communication method. The wired communication unit 12 is connected to a communication network N. The control unit 10 bridges a wireless terminal T connected to the wireless communication unit 11 and the communication network N connected to the wired communication unit 12.

[0033] 3 is a diagram showing an example of the configuration of the control unit 10. The control unit 10 includes an acquisition unit 13, a determination unit 14, and an output unit 15 as functional units for implementing a function of supporting the wireless terminal T in switching the access point 1 (hereinafter, also referred to as "AP steering"). These functional units are implemented by the CPU of the control unit 10 executing information processing according to a program.

[0034] The acquisition unit 13 acquires, from the wireless terminal T, quality data representing the communication quality between each access point 1 and the wireless terminal T. Specifically, the acquisition unit 13 acquires, from the wireless terminal T connected to its own access point 1, quality data (first quality data) representing the communication quality between its own access point 1 and the wireless terminal T, and quality data (second quality data) representing the communication quality between an access point 1 other than its own access point 1 and the wireless terminal T.

[0035] For example, when wireless terminal T is connected to access point 1A, the acquisition unit 13 of access point 1A acquires from wireless terminal T quality data (first quality data) representing the communication quality between access point 1A and wireless terminal T, quality data (second quality data) representing the communication quality between access point 1B and wireless terminal T, and quality data (second quality data) representing the communication quality between access point 1C and wireless terminal T.

[0036] The communication quality is, for example, a received signal strength indicator (RSSI). That is, the communication quality is represented by the strength of the radio wave received by the wireless terminal T from the access point 1. For example, the wireless terminal T measures the RSSI of the beacon every time it receives a beacon periodically transmitted from the access point 1. It is not limited to the RSSI, and a signal to noise ratio (SNR) or the like may be used.

[0037] The acquisition unit 13 further acquires status data representing a communication congestion state of each access point 1. Specifically, the acquisition unit 13 acquires status data (first status data) representing a communication congestion state of the own access point 1 from the own access point 1, and acquires status data (second status data) representing a communication congestion state of the other access point 1 from an access point 1 other than the own access point 1.

[0038] For example, the acquisition unit 13 of access point 1A acquires status data (first status data) representing the communication congestion state of access point 1A from the wireless communication unit 11, acquires status data (second status data) representing the communication congestion state of access point 1B from access point 1B, and acquires status data (second status data) representing the communication congestion state of access point 1C from access point 1C.

[0039] The status data (second status data) of another access point 1 is transmitted from the other access point 1 to the access point 1 by network communication via the communication network N. The status data may include a channel utilization rate (also called utilization) in the access point 1, or may include the number of wireless terminals T connected to the access point 1. The channel utilization rate is measured by the access point 1.

[0040] The determination unit 14 determines whether or not the wireless terminal T should connect to another access point 1 rather than its own access point 1, based on the quality data and state data acquired by the acquisition unit 13. Furthermore, the determination unit 14 selects one access point 1 to which the wireless terminal T should connect, from among the multiple other access points 1. The specific determination method used by the determination unit 14 will be described in detail later.

[0041] When the determination unit 14 determines that the wireless terminal T should be connected to another access point 1 rather than its own access point 1, the output unit 15 outputs a switching command to prompt the wireless terminal T to connect to the other access point 1. When the wireless terminal T receives the switching command from the currently connected access point 1, it switches the connection to the other access point 1 specified by the switching command.

[0042] 4 is a diagram showing an example of a switching judgment pattern used for judgment by the judgment unit 14. Five switching judgment patterns are prepared, and one of these switching judgment patterns is set in the judgment unit 14. It is preferable that the same switching judgment pattern is set for multiple access points 1.

[0043] Depending on whether "AP steering" that assists wireless terminal T in switching access point 1 is disabled (Disable) or enabled (Enable), switching judgment pattern is divided into switching judgment patterns 1 and switching judgment patterns 2 to 5. In switching judgment pattern 1, this function is disabled, and in switching judgment patterns 2 to 5, this function is enabled.

[0044] Furthermore, the switching determination patterns 2 to 5 are each classified according to whether the use of the CH usage rate (channel usage rate) is enabled (Enable) or disabled (Disable) and whether the use of the number of connected terminals is enabled (Enable) or disabled (Disable).

[0045] In switching determination pattern 2, the use of CH utilization rate and the use of the number of connected terminals are disabled. In switching determination pattern 3, the use of CH utilization rate is enabled, and the use of the number of connected terminals is disabled. In switching determination pattern 4, the use of CH utilization rate is disabled, and the use of the number of connected terminals is enabled. In switching determination pattern 5, the use of CH utilization rate and the use of the number of connected terminals are enabled.

[0046] 5 is a diagram showing an example of an evaluation formula used in each switching determination pattern. When the evaluation formula shown in the figure is satisfied, the determination unit 14 determines that the wireless terminal T should be connected to another access point 1 rather than its own access point 1.

[0047] SS represents an RSSI value. Source AP represents the access point 1 to which the wireless terminal T is connected, and SS[Source AP] represents the RSSI value between the access point 1 and the wireless terminal T.

[0048] Target AP represents another access point 1, and SS[Target AP] represents the RSSI value of the other access point 1 and the wireless terminal T. When there are multiple other access points 1, the access point 1 with the largest SS[Target AP] is selected. In practice, the access point 1 at the destination of the wireless terminal T is selected.

[0049] C1 is a coefficient according to the CH usage rate. The higher the CH usage rate of the access point 1, the smaller C1 becomes than 1, and the higher the CH usage rate of the other access point 1, the larger C1 becomes than 1. C1 may be a value according to only the CH usage rate of either the access point 1 or the other access point 1.

[0050] C2 is a coefficient according to the number of connected terminals. The larger the number of connected terminals of the own access point 1 is relatively, the smaller C2 becomes than 1, and the larger the number of connected terminals of another access point 1 is relatively, the larger C2 becomes than 1. C2 may be a value according to the number of connected terminals of only one of the own access point 1 and the other access point 1.

[0051] The evaluation formula for switching determination pattern 2 (use of CH utilization rate and use of the number of connected terminals is disabled) is to evaluate whether SS[Target AP] is equal to or greater than a threshold value obtained by adding a fixed value X to SS[Source AP].

[0052] The evaluation formula for switching judgment pattern 3 (use of CH utilization rate is enabled, use of the number of connected terminals is disabled) is to evaluate whether SS[Target AP] is equal to or greater than a threshold value obtained by adding a value obtained by multiplying SS[Source AP] by a fixed value X and a coefficient C1 according to the CH utilization rate.

[0053] The evaluation formula for switching judgment pattern 4 (use of CH utilization rate is disabled, use of the number of connected terminals is enabled) is to evaluate whether SS[Target AP] is equal to or greater than a threshold value obtained by adding a value obtained by multiplying SS[Source AP] by a fixed value X and a coefficient C2 according to the number of connected terminals.

[0054] The evaluation formula for switching judgment pattern 5 (use of CH utilization rate and number of connected terminals is effective) is to evaluate whether SS[Target AP] is equal to or greater than a threshold value obtained by adding a fixed value X to SS[Source AP] multiplied by a coefficient C1 according to the CH utilization rate and a coefficient C2 according to the number of connected terminals.

[0055] 6 to 11 are diagrams for explaining examples of switching of access point 1. Here, an example of switching of access point 1 when using an evaluation formula for switching judgment pattern 5 is explained. Character strings next to each access point 1 indicate the CH usage rate (UT) and the number of connected terminals (CN).

[0056] These figures show an example of switching from access point 1A to access point 1B when a wireless terminal T, which is located within the radio wave coverage area WA of access point 1A and connected to access point 1A, moves within the radio wave coverage area WB of access point 1B.

[0057] Conventionally, switching to access point 1B occurs only when wireless terminal T reaches position C outside the radio wave coverage area WA of access point 1A, resulting in periods of lost connection and degraded performance.

[0058] In contrast, in this embodiment, the RSSI and even the communication congestion state are compared to determine whether the wireless terminal T should connect to access point 1B rather than access point 1A, making it possible to switch to access point 1B in the intermediate range Wm that belongs to both the radio wave coverage ranges WA and WB.

[0059] 6, the CH usage rate of access point 1A is 20% and the number of connected terminals is 30, while the CH usage rate of access point 1B is also 20% and the number of connected terminals is also 30. That is, the CH usage rate and the number of connected terminals are equivalent in access points 1A and 1B. In this case, the evaluation formula for switching judgment pattern 5 is the same as the evaluation formula for switching judgment pattern 2, because coefficient C1 according to the CH usage rate and coefficient C2 according to the number of connected terminals are both 1.

[0060] In this example, switching position P at which the connection is switched from access point 1A to access point 1B is a position within intermediate range Wm that is approximately the same distance from access point 1A as it is from access point 1B. More specifically, since a fixed value X is added to the right-hand side of the evaluation formula, switching position P is a position slightly closer to access point 1B than to access point 1A.

[0061] In the example of Fig. 7, the CH utilization rate of access point 1A is 20% and the number of connected terminals is 30, while the CH utilization rate of access point 1B is 50% and the number of connected terminals is 30. That is, the CH utilization rate of access point 1B is higher than that of access point 1A. On the other hand, the number of connected terminals is the same for access points 1A and 1B. In this case, the evaluation formula for switching determination pattern 5 is the same as the evaluation formula for switching determination pattern 3 because coefficient C2 according to the number of connected terminals is 1.

[0062] In this example, the switching position P is a position within the intermediate range Wm that is closer to the access point 1B than to the access point 1A. That is, since the CH usage rate of the access point 1B is higher than the CH usage rate of the access point 1A, the switching to the access point 1B is delayed more than in the example of FIG. 6 above.

[0063] In the example of Figure 8, the CH utilization rate of access point 1A is 50%, and the number of connected terminals is 30, while the CH utilization rate of access point 1B is 20%, and the number of connected terminals is 30. That is, the CH utilization rate of access point 1A is higher than the CH utilization rate of access point 1B. Meanwhile, the number of connected terminals is the same for access points 1A and 1B. In this case as well, the evaluation formula for switching determination pattern 5 is the same as the evaluation formula for switching determination pattern 3, since coefficient C2 according to the number of connected terminals becomes 1.

[0064] In this example, the switching position P is a position within the intermediate range Wm that is closer to the access point 1A than to the access point 1B. That is, since the CH usage rate of the access point 1A is higher than the CH usage rate of the access point 1B, the switching to the access point 1B is performed earlier than in the example of FIG.

[0065] In the example of Fig. 9, the CH usage rate of access point 1A is 20% and the number of connected terminals is 30, while the CH usage rate of access point 1B is 20% and the number of connected terminals is 60. That is, the number of connected terminals of access point 1B is greater than the number of connected terminals of access point 1A. On the other hand, the CH usage rates of access points 1A and 1B are equivalent. In this case, the evaluation formula for switching determination pattern 5 is the same as the evaluation formula for switching determination pattern 4, because coefficient C1 according to the CH usage rate is 1.

[0066] In this example, the switching position P is a position within the intermediate range Wm that is closer to the access point 1B than to the access point 1A. That is, since the number of connected terminals to the access point 1B is greater than the number of connected terminals to the access point 1A, the switching to the access point 1B is delayed more than in the example of FIG. 6 above.

[0067] In the example of Fig. 10, the CH utilization rate of access point 1A is 20% and the number of connected terminals is 60, while the CH utilization rate of access point 1B is 20% and the number of connected terminals is 30. That is, the number of connected terminals of access point 1A is greater than the number of connected terminals of access point 1B. On the other hand, the CH utilization rates of access points 1A and 1B are equivalent. In this case as well, the evaluation formula for switching determination pattern 5 is the same as the evaluation formula for switching determination pattern 4, since coefficient C1 according to the CH utilization rate becomes 1.

[0068] In this example, the switching position P is a position within the intermediate range Wm that is closer to the access point 1A than to the access point 1B. That is, since the number of terminals connected to the access point 1A is greater than the number of terminals connected to the access point 1B, the switching to the access point 1B is performed earlier than in the example of FIG.

[0069] In the example of Fig. 11, the CH utilization rate of access point 1A is 20% and the number of connected terminals is 60, while the CH utilization rate of access point 1B is 50% and the number of connected terminals is 30. That is, the CH utilization rate of access point 1B is higher than that of access point 1A. On the other hand, the number of connected terminals of access point 1A is greater than that of access point 1B. In this example, the switching position P is determined according to the weighting of coefficient C1 according to the CH utilization rate and coefficient C2 according to the number of connected terminals.

[0070] For example, when the weight of coefficient C1 corresponding to the CH usage rate is greater than coefficient C2 corresponding to the number of connected terminals, the CH usage rate of access point 1B is higher than the CH usage rate of access point 1A, so that, as in the example of Figure 7 above, switching position P will be a position within the intermediate range Wm closer to access point 1B than to access point 1A.

[0071] On the other hand, when the weighting of coefficient C2 according to the number of connected terminals is greater than the weighting of coefficient C1 according to the CH usage rate, the number of connected terminals to access point 1A is greater than the number of connected terminals to access point 1B, so that, as in the example of Figure 10 above, switching position P will be a position within the intermediate range Wm closer to access point 1A than to access point 1B.

[0072] 12 and 13 are diagrams showing an example of a procedure of a control method for a wireless terminal T realized in the access point 1. The control unit 10 of the access point 1 executes the information processing shown in these diagrams in accordance with a program.

[0073] First, the control unit 10 determines whether "AP steering" is disabled (Disable) or enabled (Enable) (S11). If "AP steering" is disabled (S11: Disable), the control unit 10 ends the process.

[0074] When “AP steering” is enabled (S11: Enable), the control unit 10 executes in parallel the collection of RSSI (S20), the collection of CH utilization rate (S30), the collection of the number of connected terminals (S40), and evaluation / mobility control (S50).

[0075] The collection of RSSI (S20), the collection of CH utilization rate (S30), and the collection of the number of connected terminals (S40) are processes performed by the acquisition unit 13, and the evaluation / mobility control (S50) is processes performed by the determination unit 14 and the output unit 15 (see FIG. 3).

[0076] In collecting RSSI (S20), the control unit 10 collects RSSI from wireless terminals T connected to its own access point 1, and executes a process of waiting for a certain period of time (S21 and S22) for all wireless terminals T. Specifically, the control unit 10 obtains from the wireless terminal T the RSSI between its own access point 1 and wireless terminal T, and the RSSI between an access point 1 other than its own access point 1 and wireless terminal T.

[0077] When the use of CH utilization rates is enabled (S12: Enable), the control unit 10 executes collection of CH utilization rates (S30). In collection of CH utilization rates (S30), the control unit 10 executes processing of collecting CH utilization rates from surrounding access points 1 and waiting for a certain period of time (S31 and S32) for all surrounding access points 1. On the other hand, when the use of CH utilization rates is disabled (S12: Disable), the control unit 10 ends the processing.

[0078] When the use of the number of connected terminals is enabled (S13: Enable), the control unit 10 executes collection of the number of connected terminals (S40). In collection of the number of connected terminals (S40), the control unit 10 collects the number of connected terminals from the surrounding access points 1, and executes the process of waiting for a certain period of time (S41 and S42) for all surrounding access points 1. On the other hand, when the use of the number of connected terminals is disabled (S13: Disable), the control unit 10 ends the process.

[0079] In evaluation / mobility control (S50), evaluation / mobility control of wireless terminal T is executed, and a process of waiting for a certain period of time (S51 and S52) is executed for all wireless terminals T. The mobility control of wireless terminal T is a process of outputting a switching command to prompt wireless terminal T to connect to another access point 1.

[0080] 13, in evaluation / mobility control of wireless terminal T (S51), the control unit 10 checks whether data of (A) RSSI, (B) CH utilization rate, and (C) number of connected terminals exists (S61-64), determines whether an evaluation formula for a switching determination pattern holds (S65-68), and executes mobility control of wireless terminal T if the evaluation formula for the switching determination pattern holds (S69). The control unit 10 executes these processes for all wireless terminals T (S60).

[0081] Specifically, if (A) RSSI data is present and (B) CH utilization rate and (C) number of connected terminals data is not present (S61: YES, S62, S63: NO), the control unit 10 determines whether the evaluation formula for switching determination pattern 2 is satisfied (S65, see Figures 4 and 5).

[0082] Furthermore, if (A) RSSI and (B) CH utilization rate data is present, but (C) the number of connected terminals data is not present (S61, S63: YES, S62: NO), the control unit 10 determines whether the evaluation formula for switching determination pattern 3 is satisfied (S66, see Figures 4 and 5).

[0083] Furthermore, if data on (A) RSSI and (C) the number of connected terminals is present, but data on (B) CH utilization rate is not present (S61, S62: YES, S64: NO), the control unit 10 determines whether the evaluation formula for switching determination pattern 4 is satisfied (S67, see Figures 4 and 5).

[0084] Furthermore, if data on (A) RSSI, (B) CH utilization rate, and (C) number of connected terminals is present (S61, S62, S64: YES), the control unit 10 determines whether the evaluation formula for switching determination pattern 5 holds (S68, see Figures 4 and 5).

[0085] When any one of the evaluation formulas of the switching determination patterns 2 to 5 is satisfied (S65, S66, S67, S68: YES), the control unit 10 executes the movement control of the wireless terminal T (S69). That is, the control unit 10 outputs a switching command to the wireless terminal T to prompt the wireless terminal T to connect to another access point 1 (Target AP).

[0086] In addition, (A) if there is no RSSI data (S61: NO) or none of the evaluation formulas for switching determination patterns 2 to 5 is satisfied (S65, S66, S67, S68: NO), the control unit 10 does not execute mobility control for the wireless terminal T.

[0087] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made by those skilled in the art.

[0088] For example, the above-mentioned acquisition unit 13, determination unit 14, and output unit 15 are not limited to being implemented by the control unit 10 of the access point 1, and may be implemented by other devices such as the server 9.

[0089] Representative embodiments of the present invention will be listed below.

[0090] (1) An access point, an acquisition unit that acquires, from a wireless terminal connected to the access point, first quality data representing a communication quality between the access point and the wireless terminal, and second quality data representing a communication quality between an access point other than the access point and the wireless terminal; a determination unit that determines whether or not the wireless terminal should connect to the other access point rather than the access point based on the first quality data and the second quality data; an output unit that outputs a switching command to prompt the wireless terminal to connect to the other access point when it is determined that the wireless terminal should connect to the other access point; An access point comprising:

[0091] (2) The acquisition unit further acquires at least one of first status data representing a communication congestion state of the access point and second status data representing a communication congestion state of the other access point; the determination unit determines whether or not to connect to the other access point based further on at least one of the first status data and the second status data. (1) An access point as described above.

[0092] (3) the first status data includes a channel utilization rate at the access point; the second status data includes a channel utilization rate at the other access point; (2) An access point as described above.

[0093] (4) the first status data includes a number of wireless terminals connected to the access point; the second status data includes a number of wireless terminals connected to the other access point; An access point described in (2) or (3).

[0094] (5) the determination unit determines that a connection should be made to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold obtained by adding a predetermined value to the value representing the communication quality between the access point and the wireless terminal. An access point according to any one of (1) to (4).

[0095] (6) the determination unit determines that a connection should be made to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a value corresponding to at least one of a channel usage rate at the access point and a channel usage rate at the other access point to the value representing the communication quality between the access point and the wireless terminal. An access point according to any one of (2) to (4).

[0096] (7) the determination unit determines that the wireless terminal should be connected to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a value corresponding to at least one of the number of wireless terminals connected to the access point and the number of wireless terminals connected to the other access point to the value representing the communication quality between the access point and the wireless terminal. An access point according to any one of (2) to (4).

[0097] (8) the determination unit determines that the wireless terminal should be connected to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a value representing the communication quality between the access point and the wireless terminal to at least one of a channel usage rate at the access point and the number of wireless terminals connected to the access point, and a channel usage rate at the other access point and the number of wireless terminals connected to the other access point. An access point according to any one of (2) to (4).

[0098] (9) the access point uses one of a plurality of determination patterns to determine whether to connect to the other access point; The other access point also uses the same judgment pattern as the one judgment pattern. An access point according to any one of (1) to (8).

[0099] (10) The communication quality is a received signal strength indicator (RSSI), An access point according to any one of (1) to (9).

[0100] (11) the acquiring unit acquires a plurality of the second quality data representing communication qualities between a plurality of the other access points and the wireless terminal; the determination unit selects one of the other access points to which the wireless terminal should be connected, based on the second quality data. An access point according to any one of (1) to (10).

[0101] (12) acquiring, from a wireless terminal connected to a first access point, first quality data representing a communication quality between the first access point and the wireless terminal, and second quality data representing a communication quality between the wireless terminal and a second access point different from the first access point; determining whether the wireless terminal should connect to the second access point rather than the first access point based on the first quality data and the second quality data; when it is determined that the wireless terminal should connect to the second access point, outputting a switching command to prompt the wireless terminal to connect to the second access point; A method for controlling a wireless terminal.

[0102] (13) acquiring first quality data representing a communication quality between the first access point and the wireless terminal, the first quality data being acquired by the first access point from a wireless terminal connected to the first access point, and second quality data representing a communication quality between the wireless terminal and a second access point different from the first access point; and determining whether the wireless terminal should connect to the second access point rather than the first access point based on the first quality data and the second quality data; A program for causing a computer to execute the following. [Explanation of symbols]

[0103] 1 access point, 10 control unit, 11 wireless communication unit, 12 wired communication unit, 13 acquisition unit, 14 determination unit, 15 output unit, 7 network switch, 8 router, 9 server, 100 access point control system, T wireless terminal

Claims

1. An access point, an acquisition unit that acquires, from a wireless terminal connected to the access point, first quality data representing a communication quality between the access point and the wireless terminal, and second quality data representing a communication quality between an access point other than the access point and the wireless terminal; a determination unit that determines whether or not the wireless terminal should connect to the other access point rather than the access point based on the first quality data and the second quality data; an output unit that outputs a switching command to prompt the wireless terminal to connect to the other access point when it is determined that the wireless terminal should connect to the other access point; An access point comprising:

2. The acquisition unit further acquires at least one of first status data representing a communication congestion state of the access point and second status data representing a communication congestion state of the other access point; the determination unit determines whether or not to connect to the other access point based further on at least one of the first status data and the second status data. The access point of claim 1 .

3. the first status data includes a channel utilization rate at the access point; the second status data includes a channel utilization rate at the other access point; 3. The access point of claim 2.

4. the first status data includes a number of wireless terminals connected to the access point; the second status data includes a number of wireless terminals connected to the other access point; 3. The access point of claim 2.

5. the determination unit determines that a connection should be made to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold obtained by adding a predetermined value to the value representing the communication quality between the access point and the wireless terminal. The access point of claim 1 .

6. the determination unit determines that a connection should be made to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a value corresponding to at least one of a channel usage rate at the access point and a channel usage rate at the other access point to the value representing the communication quality between the access point and the wireless terminal.

3. The access point of claim 2.

7. the determination unit determines that the wireless terminal should be connected to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a value corresponding to at least one of the number of wireless terminals connected to the access point and the number of wireless terminals connected to the other access point to the value representing the communication quality between the access point and the wireless terminal.

3. The access point of claim 2.

8. the determination unit determines that the wireless terminal should be connected to the other access point when a value representing a communication quality between the other access point and the wireless terminal is equal to or greater than a threshold value obtained by adding a value representing the communication quality between the access point and the wireless terminal to at least one of a channel usage rate at the access point and the number of wireless terminals connected to the access point, and a channel usage rate at the other access point and the number of wireless terminals connected to the other access point.

3. The access point of claim 2.

9. the access point uses one of a plurality of determination patterns to determine whether to connect to the other access point; The other access point also uses the same judgment pattern as the one judgment pattern. The access point of claim 1 .

10. The communication quality is a received signal strength indicator (RSSI). The access point of claim 1 .

11. the acquiring unit acquires a plurality of the second quality data representing communication qualities between a plurality of the other access points and the wireless terminal; the determination unit selects one of the other access points to which the wireless terminal should be connected, based on the plurality of second quality data. The access point of claim 1 .

12. acquiring, from a wireless terminal connected to a first access point, first quality data representing a communication quality between the first access point and the wireless terminal, and second quality data representing a communication quality between the wireless terminal and a second access point different from the first access point; determining whether the wireless terminal should connect to the second access point rather than the first access point based on the first quality data and the second quality data; when it is determined that the wireless terminal should connect to the second access point, outputting a switching command to prompt the wireless terminal to connect to the second access point; A method for controlling a wireless terminal.

13. acquiring first quality data acquired by a first access point from a wireless terminal connected to the first access point, the first quality data representing a communication quality between the first access point and the wireless terminal, and second quality data representing a communication quality between a second access point different from the first access point and the wireless terminal; and determining whether the wireless terminal should connect to the second access point rather than the first access point based on the first quality data and the second quality data; A program for causing a computer to execute the following.

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