JP2020053888A - Access point, communication method and program - Google Patents

Abstract

To provide an access point and the like capable of suppressing occurrence of disconnection of a communication link with a communication terminal.SOLUTION: An access point 100 is one of a plurality of access points that are mutually communicable. The plurality of access points respectively communicate with a communication terminal by using the same BSSID (Basic Service Set Identifier). The access point 100 comprises: a calculation unit 130 that calculates a first index value on the basis of a received wireless signal; a second communication unit 120 that receives a second index value; a comparator 140 that compares the first index value and the second index value with each other; and a controller 150 that executes establishment processing for establishing a communication link with a communication terminal 200 in a case where it is determined that a communication quality indicated by the first index value is higher than that indicated by the second index value.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an access point, a communication method executed by the access point, and a program.

  2. Description of the Related Art There is a communication system in which a plurality of access points are connected to each other by wireless communication and transfer communication packets (also simply referred to as packets) in a multi-hop manner.

  Patent Literature 1 discloses a system including a plurality of access points (mesh access points) configuring a wireless mesh network (also simply referred to as a mesh network) as an example of a communication system that performs multi-hop transfer. The system described in Patent Literature 1 calculates a performance value of each access point based on backhaul link information, and selects an access point with which to communicate based on the calculated performance value.

JP 2008-47266 A

  When a plurality of access points constituting a mesh network and a communication terminal used by a user perform wireless communication, the communication terminal establishes a communication link with an access point having higher communication quality using, for example, a roaming function. Try to maintain high communication quality.

  Here, when the communication terminal changes the communication link from one access point to another using the roaming function, the communication link is disconnected (so-called handoff or handover) due to a handshake process or the like. As a result, for example, when a telephone call is made via the mesh network, a problem such as interruption of the voice occurs.

  Therefore, the present invention provides an access point or the like that can suppress occurrence of disconnection of a communication link with a communication terminal.

  An access point according to an aspect of the present invention is one of communication systems including a plurality of access points that can communicate with each other, and the plurality of access points are each the same Basic Service Set Identifier (BSSID). ), The access point communicates with the communication terminal using the first communication unit for receiving a wireless signal from the communication terminal, and the communication terminal based on the wireless signal received via the first communication unit. A calculation unit for calculating a first index value indicating the quality of communication with the communication terminal; a second communication unit for receiving a second index value indicating the quality of communication between another access point and the communication terminal; A comparison unit that compares the first index value calculated by the unit, and the second index value received via the second communication unit, If the comparison unit determines that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value, the communication unit executes an establishment process for establishing a communication link with the communication terminal. And a control unit that performs the control.

  When an access point and a communication terminal establish a communication link, the communication terminal individually establishes a communication link with a specific access point by individually recognizing the access point based on the BSSID received from the access point. Therefore, when a plurality of access points communicate with the communication terminal using the same BSSID, the communication terminal cannot distinguish and recognize each of the plurality of access points. In other words, the communication terminal recognizes each of a plurality of access points communicating using the same BSSID as one access point. Therefore, the communication terminal can communicate with all of the plurality of access points by establishing a communication link with any of the plurality of access points. This eliminates the need for the communication terminal to re-establish a communication link even when the communication destination access point changes, thereby suppressing the occurrence of communication disconnection. That is, according to the access point of one embodiment of the present invention, occurrence of disconnection of a communication link with a communication terminal can be suppressed. Also, when a plurality of access points communicate using the same BSSID, all access points that have received a signal from the communication terminal perform the same processing, such as transferring the received signal to the other communication terminal. Resulting in. Therefore, the access point according to one embodiment of the present invention exchanges an index value indicating the communication quality of the communication terminal with another access point. Further, the access point according to one aspect of the present invention, the index value of its own device, comparing the received index value of the other access point, when it is determined that the own device is higher communication quality, Establish a communication link with the communication terminal. By doing so, only the access point with high communication quality can establish a communication link with the communication terminal, and performs communication with the communication terminal. Further, when the communication terminal changes the access point of the communication destination, for example, the access point takes the terminal information for carrying out communication with the communication terminal received from the communication terminal, and then carries out communication with the communication terminal. Send to another access point. Further, for example, the access point stops communication with the communication terminal. By doing so, even when the access point that communicates with the communication terminal is changed, only the access point with high communication quality can perform communication with the communication terminal.

  For example, the access point according to one aspect of the present invention further includes a storage unit that stores the first index value and the second index value, and the control unit performs the first index value in the establishment process. When the comparison unit determines that the communication quality indicated by the communication unit is higher than the communication quality indicated by the second index value, the communication unit includes a MAC (Media Access Control) address of the communication terminal and the first index value. The first connection information is transmitted to the other access point via the second communication unit, and the second connection information including the MAC address of the communication terminal and the second index value is transmitted from the other access point to the second access point. (2) When receiving via the communication unit, the comparison unit compares the first index value stored in the storage unit with the second index value included in the second connection information. If the communication quality indicated by the first index value stored in the storage unit is higher than the communication quality indicated by the second index value included in the second connection information, the comparing unit If it is determined, a communication link with the communication terminal is established, and the communication quality indicated by the first index value stored in the storage unit is the second communication information included in the second connection information. If the comparison unit determines that the communication quality is lower than the communication quality indicated by the two index values, the communication link with the communication terminal is not established.

  According to such a configuration, for example, it is possible to suppress a plurality of access points from erroneously establishing a communication link with a communication terminal. Therefore, according to such a configuration, only one of the plurality of access points can easily establish a communication link with the communication terminal.

  Also, for example, the calculating unit, after the control unit has established a communication link with the communication terminal, when receiving a wireless signal from the communication terminal via the first communication unit, the received wireless signal Calculating a third index value indicating the quality of communication with the communication terminal based on the third index value, and comparing a reference index value indicating a predetermined communication quality, The control unit, when the comparing unit determines that the communication quality indicated by the third index value is lower than the communication quality indicated by the reference index value, the third index value is transmitted to the other access point. Is transmitted via the second communication unit, and from the other access point, the quality of communication between the other access point and the communication terminal is higher than the quality of communication indicated by the third index value. Indicating the communication information in the second communication When receiving the communication via the second communication unit, transmits the terminal information for carrying out communication with the communication terminal to the other access point, and stops communication with the established communication terminal. I do.

  According to such a configuration, for example, an access point currently in charge of communication with a communication terminal can compare with the communication quality of another access point when the communication quality is degraded. Accordingly, it is possible to appropriately select and execute whether to continue communication with the communication terminal or stop communication by causing another access point to perform communication with the communication terminal. Therefore, the communication terminal can suppress the occurrence of communication disconnection when the access point of the communication destination changes, and can maintain high communication quality.

  Also, for example, the calculation unit calculates a received signal strength of a radio signal received from the communication terminal via the first communication unit as the third index value, and the comparison unit calculates the third index value as the third index value. The third received signal strength indicated is compared with the fourth received signal strength indicated by the fourth index value, and the higher received signal strength is determined to be higher in communication quality.

  According to such a configuration, the access point can compare the quality of communication with another access point using the received signal strength (RSSI / Received Signal Strength Indicator) that can be easily detected. Therefore, the occurrence of communication disconnection when the communication terminal changes the access point of the communication destination can be suppressed with a simpler configuration.

  Also, for example, the plurality of access points constitute a mesh network, the calculation unit calculates a metric value as the third index value, and the comparison unit calculates a third metric value indicated by the third index value. The value and the fourth metric value indicated by the fourth index value are compared, and the one with the lower metric value is determined to have higher communication quality.

  According to such a configuration, the access point can compare the communication quality with another access point using the metric value that can be easily detected. Therefore, the occurrence of communication disconnection when the communication terminal changes the access point of the communication destination can be suppressed with a simpler configuration.

  Also, for example, the plurality of access points constitute a mesh network, and the calculation unit is configured to perform a process based on a reception signal strength of a radio signal received from the communication terminal via the first communication unit, and a metric value. The third index value is calculated.

  According to such a configuration, the access point can compare the quality of communication with other access points using the metric value and the received signal strength that can be easily detected. Therefore, the occurrence of communication disconnection when the communication terminal changes the access point of the communication destination can be suppressed with a simpler configuration, and communication can be performed with an access point having higher communication quality. Further, according to such a configuration, for example, when a difference between one of the metric value and the received signal strength is extremely small, the access point can compare the other with the other. Therefore, the communication terminal, compared to the case of comparing the communication quality using only the metric value or only the received signal strength, it is easier to establish a communication link with the access point higher communication quality, and, Even when the communication terminal changes the access point of the communication destination, it is possible to make it easier for the access point having higher communication quality to carry out the communication.

  Also, for example, the calculation unit is calculated from own device position information indicating the position of the access point and terminal position information indicating the position of the communication terminal received from the communication terminal via the first communication unit. Calculating the distance between the access point and the communication terminal as the third index value, wherein the comparing unit calculates a third distance indicated by the third index value and a fourth distance indicated by the fourth index value Are determined, and the smaller the distance, the higher the communication quality.

  According to such a configuration, the access point can compare the quality of communication with another access point based on the distance between the access point and the communication terminal. As described above, by using the position information that can be detected with a simple configuration, the occurrence of communication disconnection when the communication terminal changes the access point of the communication destination can be suppressed with a simpler configuration, and the communication quality can be improved. Can communicate with access points with high

  Also, for example, the calculation unit calculates a received signal strength of a radio signal received from the communication terminal via the first communication unit as the first index value, and the comparison unit calculates the first index value as the first index value. The first received signal strength shown is compared with the second received signal strength shown in the second index value, and the higher received signal strength is determined to be higher in communication quality.

  According to such a configuration, the access point can compare the quality of communication with other access points using the received signal strength that can be easily detected. Therefore, the occurrence of communication disconnection when the communication terminal changes the access point of the communication destination can be suppressed with a simpler configuration.

  Also, for example, the plurality of access points constitute a mesh network, the calculation unit calculates a metric value as the first index value, and the comparison unit calculates a first metric value indicated by the first index value. The value is compared with a second metric value indicated by the second index value, and the one with the lower metric value is determined to have higher communication quality.

  According to such a configuration, the access point can compare the communication quality with another access point using the metric value that can be easily detected. Therefore, the occurrence of communication disconnection when the communication terminal changes the access point of the communication destination can be suppressed with a simpler configuration.

  Also, for example, the plurality of access points constitute a mesh network, and the calculation unit is configured to perform a process based on a reception signal strength of a radio signal received from the communication terminal via the first communication unit, and a metric value. The first index value is calculated.

  According to such a configuration, the access point can compare the quality of communication with other access points using the metric value and the received signal strength that can be easily detected. Therefore, the occurrence of communication disconnection when the communication terminal changes the access point of the communication destination can be suppressed with a simpler configuration, and communication can be performed with an access point having higher communication quality. Further, according to such a configuration, for example, when a difference between one of the metric value and the received signal strength is extremely small, the access point can compare the other with the other. Therefore, the communication terminal, compared to the case of comparing the communication quality using only the metric value or only the received signal strength, it is easier to establish a communication link with the access point higher communication quality, and, Even when the communication terminal changes the access point of the communication destination, it is possible to make it easier for the access point having higher communication quality to carry out the communication.

  Also, for example, the calculation unit is calculated from own device position information indicating the position of the access point and terminal position information indicating the position of the communication terminal received from the communication terminal via the first communication unit. Calculating the distance between the access point and the communication terminal as the first index value, wherein the comparing unit calculates a first distance indicated by the first index value and a second distance indicated by the second index value Are determined, and the smaller the distance, the higher the communication quality.

  According to such a configuration, the access point can compare the quality of communication with another access point based on the distance between the access point and the communication terminal. As described above, by using the position information that can be detected with a simple configuration, the occurrence of communication disconnection when the communication terminal changes the access point of the communication destination can be suppressed with a simpler configuration, and the communication quality can be improved. Can communicate with access points with high

  Further, the communication method according to an aspect of the present invention is a communication method executed by one access point of a communication system including a plurality of access points capable of communicating with each other, wherein the plurality of access points are the same. The access point communicates with the communication terminal using the BSSID of the first communication step, and the access point communicates with the communication terminal based on the wireless signal received in the first communication step. Calculating a first index value indicating the quality of the communication terminal; a second communication step receiving a second index value indicating the quality of communication between another access point and the communication terminal; A comparing step of comparing a first index value and the second index value received in the second communication step, and a communication indicated by the first index value A control step of executing an establishment process for establishing a communication link with the communication terminal when the comparison step determines that the quality is higher than the communication quality indicated by the second index value. .

  According to such a method, the communication terminal can communicate with all of the plurality of access points if a communication link is established with any of the plurality of access points. This eliminates the need for the communication terminal to re-establish a communication link even when the communication destination access point changes, thereby suppressing the occurrence of communication disconnection. That is, according to the communication method of one embodiment of the present invention, it is possible to suppress occurrence of disconnection of a communication link with a communication terminal.

  The present invention may be realized as a program that causes a computer to execute the steps included in the communication method. Further, the present invention may be realized as a recording medium such as a CD-ROM which can be read by a computer in which the program is recorded. Further, the present invention may be realized as information, data or a signal indicating the program. Then, these programs, information, data, and signals may be distributed via a communication network such as the Internet.

  According to the access point or the like of one embodiment of the present invention, it is possible to suppress occurrence of disconnection of a communication link with a communication terminal.

FIG. 1 is a schematic diagram showing a configuration of a communication system including an access point according to the embodiment. FIG. 2 is a block diagram illustrating a characteristic functional configuration of the access point according to the embodiment. FIG. 3 is a flowchart for explaining a processing procedure for establishing a communication link with a communication terminal by the access point according to the embodiment. FIG. 4 is a sequence diagram for explaining a procedure in which the access point according to the embodiment establishes a communication link with a communication terminal. FIG. 5 is a sequence diagram for describing a first modified example of a procedure in which the access point according to the embodiment establishes a communication link with a communication terminal. FIG. 6 is a sequence diagram for describing a second modification of the procedure in which the access point according to the embodiment establishes a communication link with a communication terminal. FIG. 7 is a sequence diagram for explaining a processing procedure in which the access point according to the embodiment changes an access point responsible for communication with a communication terminal.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each of the embodiments described below shows one specific example of the present invention. Numerical values, constituent elements, arrangement positions and connection forms of constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and do not limit the present invention. In addition, among the components in the following embodiments, components not described in the independent claims indicating the highest concept are described as arbitrary components. The same components and operations are denoted by the same reference numerals, and description thereof may be omitted.

(Embodiment)
[Overview of Communication System]
The configuration of a communication system including an access point according to the present embodiment will be described with reference to FIG. 1 and FIG.

  FIG. 1 is a schematic diagram showing a configuration of a communication system 500 including the access point 100 according to the embodiment. FIG. 2 is a block diagram showing a characteristic functional configuration of access point 100 according to the embodiment.

  Note that FIG. 1 illustrates access points 100a to 100i as an example of the access point 100 according to the embodiment shown in FIG. In addition, the access points 101 and 102 shown in FIG. 2 have substantially the same configuration as the access point 100, so that detailed illustration is omitted.

  In the following, any one of the plurality of access points included in the communication system 500 is referred to as an access point 100, and one or more access points different from the access point 100 among the plurality of access points included in the communication system 500 are referred to. A point may be called another access point 101 or another access point 102.

  The communication system 500 includes a plurality of access points that can communicate with each other via a network such as a LAN (Local Area Network). FIG. 1 illustrates, as an example, a case where the communication system 500 includes nine access points 100a to 100i as the access points 100.

  The plurality of access points can communicate with each other. In addition, the plurality of access points communicate with the communication terminal 200 using the same Basic Service Set Identifier (BSSID).

  Note that the plurality of access points may be communicably connected by a wire such as a communication line. In the present embodiment, a plurality of access points are connected so as to be able to perform wireless communication. More specifically, the plurality of access points constitute a mesh network 410.

  Each of the plurality of access points constituting the mesh network 410 has route information indicating a route to each access point and belonging information indicating which access point can communicate with which access point. The plurality of access points transfer packets transmitted by the communication terminal 200 that has established a communication link with one of the access points constituting the mesh network 410, using the route information and the belonging information. Thereby, the plurality of access points cause the packet transmitted by the communication terminal 200 to reach the communication terminal of the communication partner connected to the mesh network 410.

  The access point 100 establishes a communication link with the communication terminal 200, and transfers data such as a packet received from the communication terminal 200 to another access point 101 such that the packet is transferred to a destination. For example, when the communication terminal 200 transmits a packet to the external network 400 such as the Internet, the access point 100h that has received the packet from the communication terminal 200 transfers the packet to another access point 101. The access point 100h refers to the metric value stored in advance and transfers the packet to another access point 101 so that the packet is appropriately transferred to the external network 400. As shown in FIG. 1, for example, the access point 100h transfers the packet to 100d, and the access point 100d transfers the packet to 100a. Further, the access point 100a transfers the packet to the destination of the packet via the external network 400. Thus, the packet transmitted by the communication terminal 200 is transmitted to the destination via the external network 400 via one or a plurality of access points.

  In addition, the packet transmitted from the external network 400 to the communication terminal reaches the communication terminal 200 via the access point 100a, the access point 100d, and the access point 100h.

  Although FIG. 1 shows nine access points for explanation, the number of access points is not limited. The communication system 500 only needs to have two or more access points. In addition, the communication system 500 may further include a relay device that does not become an access point and transfers a received signal.

  Further, the communication protocol on the external network 400 and the communication protocol on the mesh network 410 are not particularly limited. As a communication protocol, TCP / IP (Transmission Control Protocol / Internet Protocol) may be used.

  The communication terminal 200 is a communication terminal such as a smartphone and a tablet terminal that can communicate with the access point 100. The communication terminal 200 only needs to be able to wirelessly communicate with the access point 100, and may be a device such as an unmanned carrier. The communication terminal 200 has a storage unit, which is a memory (not shown), and stores the terminal information 210 in the storage unit. The terminal information 210 is, for example, information for decrypting encrypted data that communicates with the communication terminal 200, and information including a MAC (Media Access Control) address of the communication terminal 200.

  The communication system 500 includes a controller communicably connected to one or more access points of the plurality of access points included in the communication system 500 via the mesh network 410 and communicably connected to the external network 400. You may. The controller is, for example, a higher-level controller that controls operations and the like for all the plurality of access points.

  The plurality of access points may be connected to the external network 400 or may not be connected.

[Access Point Configuration]
Next, the configuration of the access point 100 will be described in detail with reference to FIG.

  FIG. 2 is a block diagram showing a characteristic functional configuration of access point 100 according to the embodiment.

  The access point 100 includes a first communication unit 110, a second communication unit 120, a calculation unit 130, a comparison unit 140, a control unit 150, and a storage unit 160.

  The first communication unit 110 is a communication interface such as a communication adapter for communicating with the communication terminal 200. Specifically, first communication section 110 receives a wireless signal from communication terminal 200. The first communication unit 110 communicates with the communication terminal 200 using the same BSSID as the other access points 101.

  The second communication unit 120 is a communication interface such as a communication adapter for communicating with the other access points 101 and 102. More specifically, the second communication unit 120 calculates the first index value (index value) or the third index value (index value) indicating the quality of communication between the access point 100 and the communication terminal 200, calculated by the calculation unit 130. ) To the access point 101. The first index value is an index value calculated by the access point 100 before the access point 100 establishes a communication link with the communication terminal 200. The third index value is an index value calculated for the access point 100 after the access point 100 establishes a communication link with the communication terminal 200. In addition, the second communication unit 120 receives a second index value (index value) or a fourth index value (index value) indicating the quality of communication between the other access point 101 and the communication terminal 200. Note that the second index value is an index value calculated for the other access points 101 and 102 before the access point 100 establishes a communication link with the communication terminal 200. The fourth index value is an index value calculated for the other access points 101 and 102 after the access point 100 establishes a communication link with the communication terminal 200.

  For example, the index value is a received signal strength of a wireless signal received from the communication terminal 200. In addition, for example, when a plurality of access points configure the mesh network 410, the index value is a metric value calculated from a destination of a wireless signal received from the communication terminal 200.

  The metric value may be calculated differently depending on the routing protocol employed. For example, when RIP (Routing Information Protocol) is adopted as a routing protocol, the metric value is the number of hops. Also, for example, when OSPF (Open Shortest Path First) is adopted as the routing protocol, the cost value is calculated from the communication band used by the communication interface. The cost value is a value calculated under predetermined conditions such as 10 at 10 Mbps and 1 at 100 Mbps.

  Note that the index value may be a value calculated based on the received signal strength of the wireless signal received from the communication terminal 200 and a metric value calculated from the destination of the wireless signal received from the communication terminal 200. For example, the index value may be a value obtained by adding a predetermined weight to each of the received signal strength and the metric value.

  Further, the index value may be a distance between the access point 100 and the communication terminal 200. For example, the communication terminal 200 may include a GPS (Global Positioning System) receiver, and may transmit terminal position information indicating the position of the communication terminal 200 received by the GPS receiver to the access point 100. The calculation unit 130 may calculate the index value based on the terminal position information received via the first communication unit 110. For example, the storage unit 160 may store own device position information indicating the position of the access point 100. The calculating unit 130 may calculate the distance between the access point 100 and the communication terminal 200 as an index value from the position of the access point 100 indicated by the own device position information and the position of the communication terminal 200 indicated by the terminal position information. . For example, the comparing unit 140 determines that the smaller the distance calculated by the calculating unit 130 is, the higher the communication quality is. Further, the access point 100 may include a distance measuring sensor for detecting a distance from the communication terminal 200. The calculating unit 130 may calculate the first index value or the third index value based on the distance between the access point 100 and the communication terminal 200 detected by the distance measurement sensor.

  Note that the access point 100 may include a GPS receiver in order to acquire self-position information.

  Further, the first communication unit 110 and the second communication unit 120 may be realized by different communication interfaces, or may be realized by one communication interface. When the first communication unit 110 and the second communication unit 120 are realized by one communication interface, for example, the control unit 150 performs the processing of the first communication unit 110 and the processing of the second communication unit 120 described above. One communication interface is executed.

  The calculation unit 130 is a processing unit that calculates an index value indicating the quality of communication between the access point 100 and the communication terminal 200. Specifically, calculation unit 130 calculates a first index value or a third index value indicating the quality of communication between access point 100 and communication terminal 200 based on the radio signal received by first communication unit 110. Is calculated.

  The comparing unit 140 is a processing unit that compares the index values. Specifically, the comparison unit 140 is a first index value that is an index value calculated by the calculation unit 130, and an index value that is received by the second communication unit 120 and calculated by the other access points 101 and 102. The communication quality indicated by each of the second index values is compared. More specifically, the comparison unit 140 determines that the first index value calculated by the calculation unit 130 is lower in communication quality than the second index value received from the other access points 101 and 102 via the second communication unit 120. Calculate whether it is high or not. Alternatively, the comparison unit 140 may determine the third index value, which is the index value calculated by the calculation unit 130, and the fourth index, which is the index value calculated by the other access points 101 and 102, received by the second communication unit 120. The communication quality indicated by each value is compared. More specifically, the comparison unit 140 determines that the third index value calculated by the calculation unit 130 is lower in communication quality than the fourth index value received from the other access points 101 and 102 via the second communication unit 120. Calculate whether it is high or not.

  For example, the calculating unit 130 calculates, as an index value, a received signal strength of a wireless signal received by the first communication unit 110 from the communication terminal 200. In this case, the comparing unit 140 compares the first received signal strength, which is the received signal strength indicated by the first index value, with the second received signal strength, which is the received signal strength indicated by the second index value, and The higher the signal strength, the higher the communication quality. Alternatively, the comparison unit 140 compares the third received signal strength, which is the received signal strength indicated by the third index value, with the fourth received signal strength, which is the received signal strength indicated by the fourth index value, and The one with higher strength is determined to have higher communication quality.

  Further, for example, when a plurality of access points constitute the mesh network 410, the calculation unit 130 calculates a metric value as an index value. In this case, the comparison unit 140 compares the first metric value, which is the metric value indicated by the first index value, with the second metric value, which is the metric value indicated by the second index value. Is determined to have high communication quality. Alternatively, the comparing unit 140 compares the third metric value, which is the metric value indicated by the third index value, with the fourth metric value, which is the metric value indicated by the fourth index value, and determines that the metric value is lower. It is determined that the communication quality is high.

  In addition, for example, when a plurality of access points configure the mesh network 410, the calculation unit 130 may be configured to perform the determination based on both the received signal strength of the wireless signal received by the first communication unit 110 from the communication terminal 200 and the metric value. Calculate the index value. The calculation unit 130 calculates an index value by, for example, adding a predetermined weight to each of the received signal strength and the metric value and adding them. In this case, the comparison unit 140 determines that the communication quality is high when the index value calculated by the calculation unit 130 is higher than the index value received from another access point 101 via the second communication unit 120. I do. The condition for determining which one of the comparison units 140 is higher in communication quality with respect to the index value comparison result may be arbitrarily determined in advance. Further, for example, when the comparison unit 140 determines that the communication quality is the same, the comparison unit 140 may determine whether to establish a communication link with the communication terminal 200 based on a priority arbitrarily determined in advance. . Information indicating the priority may be stored in the storage unit 160.

  Further, for example, the index value may include a received signal strength and a metric value. In this case, for example, the comparing unit 140 compares the first metric value, which is the metric value indicated by the first index value, with the second metric value, which is the metric value indicated by the second index value. When the comparison unit 140 determines that the first metric value and the second metric value are the same, for example, the first reception signal strength which is the reception signal strength indicated by the first index value and the second index value Is compared with the second received signal strength which is the received signal strength indicated by. Comparing section 140 determines that the higher the received signal strength is, the higher the communication quality is. Alternatively, the comparing unit 140 compares, for example, a third metric value, which is a metric value indicated by the third index value, with a fourth metric value, which is a metric value indicated by the fourth index value. When the comparison unit 140 determines that the third metric value and the fourth metric value are the same, for example, the third reception signal strength that is the reception signal strength indicated by the third index value and the fourth index value Is compared with the fourth received signal strength which is the received signal strength indicated by. Comparing section 140 determines that the higher the received signal strength is, the higher the communication quality is.

  The control unit 150 is a processing unit that controls operations of the first communication unit 110 and the second communication unit 120. Specifically, when the comparing unit 140 determines that the communication quality of the first index value is higher than the communication quality of the second index value, the control unit 150 performs an establishment process for establishing a communication link with the communication terminal 200. Execute Here, the establishment process is not only a process in which the control unit 150 immediately establishes a communication link with the communication terminal 200, but also establishes a communication link with the communication terminal 200 when a predetermined condition is satisfied. It means that processing is included.

  The control unit 150 performs wireless communication with the communication terminal 200 via the first communication unit 110 using the same BSSID as the other access points 101.

  The access point 100 transmits the same BSSID as the other access points 101 to the communication terminal 200. Communication terminal 200 authenticates access point 100 based on the received BSSID. Thereby, the access point 100 and the communication terminal 200 establish a communication link.

  Further, the control unit 150 receives, for example, terminal information 210 for establishing a communication link with the communication terminal 200 from the communication terminal 200 via the first communication unit 110, so that the communication terminal 200 and the first communication unit Establish a communication link with 110. In this case, when the control unit 150 receives a wireless signal from the communication terminal via the first communication unit 110 after the control unit 150 establishes a communication link with the communication terminal 200, the calculation unit 130 A third index value indicating the quality of communication with the communication terminal 200 is calculated. The comparing unit 140 compares the communication quality indicated by the third index value and the communication index indicated by the reference index value 170 indicating the predetermined communication quality.

  The reference index value 170 is an index value indicating a predetermined reference quality of communication, and is stored in the storage unit 160 in advance, for example.

  When the comparing unit 140 determines that the communication quality indicated by the third index value is lower than the communication quality indicated by the reference index value 170, the control unit 150 assigns the third index value to another access point 101. , Via the second communication unit 120. Further, the control unit 150 transmits, for example, communication information indicating that the quality of communication between the other access point 101 and the communication terminal 200 is higher than the quality of communication indicated by the third index value from another access point 101, It is assumed that the data is received via the second communication unit 120. In this case, the control unit 150 transmits the terminal information 210 to another access point 101 via the second communication unit 120, and stops the established communication link with the communication terminal 200.

  For example, another access point 101 calculates a fourth index value, which is an index value indicating the quality of communication with the communication terminal 200, based on a wireless signal received from the communication terminal 200. The other access points 101 compare the calculated fourth index value with the communication quality indicated by the third index value received from the access point 100, respectively. The other access point 101 transmits the communication information to the access point 100 when determining that the communication quality indicated by the fourth index value is higher than the communication quality indicated by the third index value.

  The timing at which the other access point 101 calculates the fourth index value is not particularly limited. For example, when receiving another wireless signal from the communication terminal 200, the other access point 101 may always calculate the fourth index value. Also, for example, the other access point 101 may determine, based on a radio signal received from the communication terminal 200 within a predetermined time before and / or after the timing when the third index value is received from the access point 100, Thus, the fourth index value may be calculated.

  Further, the communication information transmitted to the access point 100 when it is determined that the communication quality indicated by the fourth index value is higher than the communication quality indicated by the third index value may be the fourth index value itself. In this case, when the other access point 101 receives the third index value, it calculates the fourth index value and compares the fourth index value with the access point without comparing the third index value with the fourth index value. 100. In this case, the comparison unit 140 included in the access point 100 receives the fourth index value via the second communication unit 120, and compares the third index value with the fourth index value. When the comparing unit 140 determines that the third index value is lower than the fourth index value, the control unit 150 transmits the terminal information 210 to another access point 101 via the second communication unit 120. Accordingly, the other access point 101 can start communication with the communication terminal 200 by receiving the terminal information 210. The other access point 101 communicates with the communication terminal 200 using the same BSSID as the access point 100. For this reason, the communication terminal 200 can communicate with the other access point 101 without executing a process for newly establishing a communication link with the other access point 101.

  Also, if the communication information is the fourth index value itself, the comparing unit 140 receives the fourth index value from each of the plurality of other access points 101 via the second communication unit 120, The fourth index value having the highest communication quality among the four index values can be determined. Therefore, the control unit 150 transmits the terminal information 210 only to the other access points 101 that transmitted the fourth index value having the highest communication quality among the plurality of fourth index values determined by the comparing unit 140. 2 can be transmitted via the communication unit 120.

  The calculation unit 130, the comparison unit 140, and the control unit 150 are realized by, for example, a CPU (Central Processing Unit) and a control program stored in the storage unit 160. The calculation unit 130, the comparison unit 140, and the control unit 150 may be individually provided with CPUs, or the calculation unit 130, the comparison unit 140, and the control unit 150 may be executed by one CPU. Processing may be implemented.

  The storage unit 160 is a memory that stores a control program executed by the calculation unit 130, the comparison unit 140, and the control unit 150.

  The storage unit 160 may store the first index value calculated by the calculation unit 130 and the second index value received via the second communication unit 120.

  In addition, the storage unit 160 stores first connection information including the MAC address of the communication terminal 200, the MAC address of its own device, and the first index value, and the MAC address of the communication terminal 200 and the MAC address of another access point 101. Second connection information including the second index value may be stored.

  By the way, there is a concern that the control unit 150 included in the access point 100 malfunctions and establishes a communication link with the communication terminal 200 when a communication link with the communication terminal 200 should not be originally established. Therefore, in the establishment process for establishing a communication link with the communication terminal 200, the control unit 150 uses connection information (first connection information) including the MAC address of the communication terminal 200, the first index value, and the MAC address of its own device. Is transmitted to the other access point 101 via the second communication unit 120. Further, the control unit 150 transmits connection information (second connection information) including the MAC address of the communication terminal 200, the second index value, and the MAC address of the other access point 101 from the other access points 101 and 102 to the second When received via the communication unit 120, the comparison unit 140 compares the quality of communication indicated by each of the first index value stored in the storage unit 160 and the second index value included in the second connection information. . The control unit 150 determines that the communication quality indicated by the first index value stored in the storage unit 160 is higher than the communication quality indicated by the second index value included in the second connection information. Is determined, a communication link with the communication terminal 200 is established. Further, the control unit 150 compares the communication quality indicated by the first index value stored in the storage unit 160 with lower quality than the communication quality indicated by the second index value included in the second connection information. If the unit 140 determines, the communication link with the communication terminal 200 is not established.

  The storage unit 160 includes, for example, one or both of a volatile memory and a non-volatile memory. The volatile memory is, for example, a RAM (Random Access Memory). The non-volatile memory is, for example, a read only memory (ROM), a hard disk drive (HDD), or a solid state drive (SSD).

  Also, for example, the calculation unit 130 may determine whether the access point 100 and the communication terminal 100 are calculated based on the own device position information and terminal position information indicating the position of the communication terminal 200 received from the communication terminal 200 via the first communication unit 110 The distance to 200 is calculated as a first index value. Comparing section 140 compares the first distance indicated by the first index value with the second distance indicated by the second index value (specifically, the distance between another access point 101 and communication terminal 200). , The smaller the distance, the higher the communication quality. Alternatively, for example, after establishing the communication link, the calculating unit 130 is calculated from the own device position information and the terminal position information indicating the position of the communication terminal 200 received from the communication terminal 200 via the first communication unit 110. The distance between the access point 100 and the communication terminal 200 is calculated as a third index value. Comparing section 140 determines the third distance indicated by the third index value and the fourth distance indicated by the fourth index value (that is, other access points after access point 100 has established a communication link with communication terminal 200). (The distance between the communication terminal 101 and the communication terminal 200), and the smaller the distance, the higher the communication quality.

[Access point processing procedure]
Next, a specific processing procedure of the access point 100 configured as described above will be described.

<Establishment of communication link>
With reference to FIGS. 3 and 4, a processing procedure for establishing a communication link between the access point 100 and the communication terminal 200 will be described.

  FIG. 3 is a flowchart illustrating a processing procedure for establishing a communication link with communication terminal 200 by access point 100 according to the embodiment.

  First, the first communication unit 110 receives a wireless signal from the communication terminal 200 (Step S101). The wireless signal is, for example, Auth req (Authentication Request / authentication request).

  Next, the calculation unit 130 calculates a first index value that is an index value based on the wireless signal received via the first communication unit 110 (Step S102).

  Next, the control unit 150 transmits the first index value calculated by the calculation unit 130 in step S102 to another access point 101 via the second communication unit 120 (step S103). For example, in step S103, the control unit 150 transmits the first index value, the MAC address of the communication terminal 200 included in the wireless signal received in step S101, and the MAC address of its own device via the second communication unit 120. To another access point 101. For example, the control unit 150 transmits such information by unicast or broadcast via the second communication unit 120.

  Next, the comparison unit 140 receives a second index value from another access point 101 via the second communication unit 120 (Step S104). In step S104, for example, the control unit 150 stores the second index value, the MAC address of the communication terminal 200 that transmitted the wireless signal for which the second index value was calculated, and the MAC address of another access point 101 in the second index value. It is received via the communication unit 120. In this way, when a plurality of access points communicate with a plurality of communication terminals 200, it is possible to easily associate the index value with the communication terminal 200.

  Next, the comparison unit 140 compares the first index value calculated by the calculation unit 130 in step S103 with the second index value received via the second communication unit 120 in step S104 (step S105). Specifically, in step S105, the comparing unit 140 determines whether the communication quality indicated by the first index value is higher than the communication quality indicated by each of the first index value and the second index value. Is determined.

  When the comparing unit 140 determines that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value (Yes in step S105), the control unit 150 determines that the other access points 101 are different. An establishment process for establishing a communication link with the communication terminal 200 is performed using the same BSSID as (step S106). In step S106, for example, the control unit 150 transmits Auth res to the communication terminal 200 via the first communication unit 110. When the communication terminal 200 receives Auth res, the communication terminal 200 transmits terminal information 210 for establishing a communication link, an Assoc req (Association request / attribution request), and the like. When receiving the terminal information 210, the Assoc req, and the like via the first communication unit 110, the control unit 150 transmits the Assoc res to the communication terminal 200. By doing so, the access point 100 establishes a communication link with the communication terminal 200.

  On the other hand, if the comparing unit 140 does not determine that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value (No in step S105), The process ends without establishing a communication link with the terminal 200.

  When the access point 100 does not receive the second index value from the other access point 101 via the second communication unit 120 in step S104, the comparison unit 140 does not perform the determination in step S105 and performs control. The unit 150 may execute the processing of Step S106. For example, when the control unit 150 has not received the second index value from another access point 101 via the second communication unit 120 for a predetermined time in step S104, the control unit 150 may execute the process of step S106. The predetermined time may be arbitrarily determined and is not particularly limited. Further, the access point 100 may include a clock unit for measuring time.

  FIG. 4 is a sequence diagram illustrating a processing procedure for establishing a communication link with communication terminal 200 by access point 100 according to the embodiment.

  First, the communication terminal 200 transmits a wireless signal (step S201).

  The first communication unit 110 transmits, for example, a beacon for notifying the presence of the access point 100 (not shown). The beacon includes the same BSSID at a plurality of access points included in the communication system 500. When receiving the beacon, the communication terminal 200 transmits a wireless signal (first wireless signal) indicating that a communication link is established with any of the plurality of access points, specifically, for example, Auth req. Here, since the wireless signal (first wireless signal) is a response to the beacon transmitted by the first communication unit 110, the wireless signal is transmitted to the access point to which the BSSID included in the beacon is set. Therefore, the wireless signal transmitted by the communication terminal 200 in step S201 is received by all the access points arranged at positions where the wireless signal can be received.

  Next, the calculation unit 130 calculates a first index value that is an index value based on the wireless signal received via the first communication unit 110 (Step S102).

  Further, the other access point 101 that has received the wireless signal calculates a second index value that is an index value based on the received wireless signal (Step S202).

  Next, the control unit 150 transmits the first index value calculated by the calculation unit 130 in step S102 to another access point 101 via the second communication unit 120 (step S103).

  The other access point 101 transmits the second index value calculated in step S202 to the access point 100 by broadcast or unicast (step S203).

  Next, the comparing unit 140 compares the first index value calculated by the calculating unit 130 in step S103 with the second index value received by the other access point 101 via the second communication unit 120. (Step S105).

  The other access point 101 compares the second index value calculated in step S202 with the first index value calculated by the access point 100 (step S204).

  The control unit 150 establishes a communication link with the communication terminal 200, for example, when the comparing unit 140 determines that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value. (Step S106).

  On the other hand, when determining that the communication quality indicated by the first index value is lower than the communication quality indicated by the second index value, the other access point 101 establishes a communication link with the communication terminal 200, for example. The processing ends without performing.

<First Modification of Establishing Communication Link>
Subsequently, a processing procedure when a plurality of access points have established a communication link with the communication terminal 200 will be described with reference to FIG. FIG. 5 illustrates three access points 100, 101, and 102.

  In FIGS. 3 and 4, when the control unit 150 determines that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value, the control unit 150 performs communication as an establishment process. The case where the communication link with the terminal 200 is immediately established is illustrated. In FIG. 5, when the control unit 150 determines that the communication quality is high, the comparing unit 140 determines that a communication link with the communication terminal 200 is to be established when the predetermined condition is satisfied. An example is shown.

  FIG. 5 is a sequence diagram for describing a first modified example of a processing procedure for establishing a communication link with communication terminal 200 by access point 100 according to the embodiment.

  First, the communication terminal 200 transmits a wireless signal (step S201).

  Next, the access points 100, 101, and 102 calculate an index value based on the received wireless signal. Specifically, the calculation unit 130 calculates a first index value that is an index value based on a wireless signal received via the first communication unit 110 (Step S102).

  Similarly to the access point 100, the other access points 101 that have received the wireless signal calculate a second index value that is an index value based on the received wireless signal (step S202). The other access point 102 calculates a second index value that is an index value based on the received wireless signal (Step S301).

  Next, the access points 100, 101, and 102 store the calculated index values (step S302). Specifically, the storage unit 160 stores the first index value calculated by the calculation unit 130 in Step S102. Further, the other access points 101 and 102 store the second index value calculated in step S202 or step S301.

  Next, the control unit 150 transmits the first index value calculated by the calculation unit 130 in step S102 to the other access points 101 and 102 via the second communication unit 120 (step S103). The point 101 transmits the second index value calculated in step S202 to the access point 100 and another access point 102 (step S203).

  Further, the other access point 102 transmits the second index value calculated in step S301 to the access point 100 and another access point 101 (step S303).

  Here, it is assumed that the access point 100 cannot receive the second index value transmitted by the other access point 101, and the other access point 101 cannot receive the first index value transmitted by the access point 100. .

  Next, the access points 100, 101, and 102 store the received index values (step S304). Therefore, the storage unit 160 of the access point 100 stores the second index value received from another access point 102. In other words, in step S304, the control unit 150 causes the storage unit 160 to store the second index value received via the second communication unit 120. Further, the other access point 101 stores the second index value received from the other access point 102. The other access point 102 stores the first index value received from the access point 100 and the second index value received from the other access point 101.

  Next, the access points 100, 101, and 102 compare the index value stored in step S302 with the index value stored in step S304. Specifically, the comparison unit 140 of the access point 100 determines the first index value calculated by the calculation unit 130 in step S102 and the second index value calculated by another access point 102 received through the second communication unit 120. The value is compared with the index value (step S105).

  The other access point 101 compares the second index value calculated in step S202 with the second index value calculated by the other access point 102 (step S204). The other access point 102 compares the second index value calculated in step S301, the first index value calculated by the access point 100, and the second index value calculated by the other access point 101.

  However, for example, the access point 100 may not always properly receive the index value calculated by another access point and store it in the storage unit 160 due to the influence of the wireless environment or the like. Here, since the access point 100 has not received the second index value transmitted by the other access point 101, it cannot compare the second index value transmitted by the other access point 101. In addition, the other access points 101 cannot receive the first index value transmitted by the access point 100, and thus cannot compare the first index value transmitted by the access point 100.

  Next, the control unit 150 of the access point 100, among the one or more index values stored in the storage unit 160, an index value with the highest communication quality and information on the access point that calculated the index value (specifically, For example, the connection information (first connection information) indicating the MAC address) is transmitted to the other access point 101 via the second communication unit 120 (step S306). As described above, in step S306, the control unit 150 does not immediately establish a communication link with the communication terminal 200, but determines that the index value of the access point 100 has the highest communication quality. The first connection information, which is information including the MAC address of the access point 100, the first index value calculated by the access point 100, and the MAC address of the communication device 200, is transmitted to the other access points 101 and 102 via the second communication unit 120. To send.

  Further, for example, when the other access point 101 determines that the index value of the other access point 101 has the highest communication quality among the one or more stored index values, for example, The second connection information, which is information including the MAC address of the point 101, the index value of the other access point 101, and the MAC address of the communication device 200, is transmitted to the access point 100 and the other access points 101 (step S307). The same applies to other access points 102 (not shown).

  Next, when the control unit 150 receives the second connection information from another access point 101 via the second communication unit 120, the storage unit 160 further stores an index value included in the received connection information. . The control unit 150 causes the comparing unit 140 to compare the communication qualities indicated by the first index value stored in the storage unit 160 and the second index value included in the second connection information (step S308). . The control unit 150 determines that the communication quality indicated by the first index value stored in the storage unit 160 is lower than the communication quality indicated by the second index value included in the second connection information. Does not establish a communication link with the communication terminal 200 (step S309).

  When the other access point 101 receives the first connection information from the access point 100, the other access point 101 further stores the first index value included in the first connection information. Further, the other access points 101 further include a first index value included in the first connection information and a second index value stored in the storage unit (specifically, a second index value calculated by the other access point 101). And (2 index values) are compared (step S310). The other access point 101 determines that the communication quality indicated by the first index value included in the first connection information is higher than the communication quality indicated by the second index value calculated by the other access point 101. If so, a communication link with the communication terminal 200 is established (step S311).

  As described above, when the access point 100 transmits the first connection information to the other access points 101 and 102 and receives the second connection information before establishing the communication link with the communication terminal 200 as the establishment processing, , The first index value stored in the storage unit 160 is compared with the second index value included in the second connection information. This suppresses a plurality of access points from establishing a communication link with the communication terminal 200.

<Second Modification of Establishing Communication Link>
Next, another example of a processing procedure when a plurality of access points have established a communication link with the communication terminal 200 will be described with reference to FIG.

  In FIG. 5, when the control unit 150 establishes a communication link with the communication terminal 200 when the comparison unit 140 determines that the communication quality is high, and when a predetermined condition is further satisfied, the establishment process is performed. An example was given. In FIG. 6, when the control unit 150 determines that the communication quality is low, the comparison unit 140 determines that the MAC address of the access point that transmitted the index value with the highest communication quality among the plurality of access points and the index The erroneous recognition prevention information associated with the value is transmitted to another access point except the own device.

  FIG. 6 is a sequence diagram for describing a second modified example of a processing procedure in which access point 100 according to the embodiment establishes a communication link with communication terminal 200.

  First, the communication terminal 200 transmits a wireless signal (step S201). Note that steps S201 to S305 shown in FIG. 6 are the same processes as steps S201 to S305 shown in FIG.

  Subsequent to step S305, the other access point 102 transmits, to the access point 100 and the other access point 101, false recognition prevention information for preventing a plurality of access points from establishing a communication link with the communication terminal 200. (Step S401). Specifically, in step S401, the other access points 102 determine the index value of the highest quality among the stored one or more index values, and information of the access point that calculated the index value (for example, the MAC address ) Is transmitted to the access point 100 and the other access points 101. As described above, in step S401, the access point that has not determined that the communication quality indicated by the index value of the own device is the highest transmits the false recognition prevention information to another access point.

  Next, the comparison unit 140 of the access point 100, for example, when the erroneous recognition prevention information is received via the second communication unit 120, the quality of the communication indicated by the first index value stored in the storage unit 160. And the communication quality indicated by the index value included in the erroneous recognition prevention information (step S402).

  Further, when the other access point 101 receives the misrecognition prevention information, for example, the communication quality indicated by the stored second index value and the communication quality indicated by the index value included in the misrecognition prevention information are different. The quality is compared (step S403).

  This suppresses a plurality of access points from establishing a communication link with the communication terminal 200.

  In step S402, for example, the comparing unit 140 compares the communication quality indicated by the first index value stored in the storage unit 160 with the communication quality indicated by the index value included in the erroneous recognition prevention information. Thus, it was determined whether to establish a communication link with the communication terminal 200. However, for example, the control unit 150 determines whether to establish a communication link with the communication terminal 200 by determining whether the MAC address included in the erroneous recognition prevention information is the MAC address of the own device. You may. The misrecognition prevention information includes the MAC address of the access point determined by the other access point 102 to have the highest communication quality. Therefore, if the MAC address included in the erroneous recognition prevention information is the MAC address of the own device, the access point has the highest communication quality.

  Also, for example, in steps S306 and S307 shown in FIG. 5, the access point that has determined that the communication quality of the own device is the highest has transmitted the connection information to another access point. Here, the access point that has not determined that the communication quality of the own device is the highest, stores the MAC address of the transmission source of the connection information or the MAC address included in the connection information when the connection information is received. It may be determined whether or not the MAC address associated with the index value indicating the highest communication quality is associated with the MAC address. Also, the access point that did not determine that the communication quality of the own device is the highest has a MAC address of the transmission source of the connection information or the MAC address included in the connection information does not match, and the comparison unit 140 The index value included in the information is compared with the index value stored in the own device, and when it is determined that the transmission quality of the connection information transmission source is lower, the connection information transmission source is , May be transmitted. Also, the access point that did not determine that the communication quality of the own device is the highest has a MAC address of the transmission source of the connection information or the MAC address included in the connection information does not match, and the comparison unit 140 The index value included in the information is compared with the index value stored in the own device, and when it is determined that the transmission source of the connection information has higher communication quality, the connection information is stored in the storage unit 160. You may memorize it. For example, the access point that has received the misrecognition prevention information may not establish a communication link with the communication terminal 200. By doing so, for example, the access point that has received the misrecognition prevention information does not need to determine whether to establish a communication link with the communication terminal 200 based on the information included in the misrecognition prevention information. When the recognition prevention information is received, the process can be terminated without establishing a communication link with the communication terminal 200.

<Communication destination change processing>
With reference to FIG. 7, a processing procedure when changing the access point 100 with which the communication terminal 200 communicates will be described.

  FIG. 7 is a sequence diagram for describing a processing procedure in which communication terminal 200 included in communication system 500 according to the embodiment changes an access point with which communication is performed. FIG. 7 illustrates a case where the communication terminal 200 communicating with the access point 100 changes the communication destination to another access point 101.

  First, it is assumed that steps S201 to S106 shown in FIG. 4 are executed by the access point 100 or the like, and the access point 100 establishes a communication link with the communication terminal 200. Note that, in FIG. 7, illustration of processing executed by the access point 100 or the like before step S106 is omitted.

  Next, the communication terminal 200 transmits a wireless signal (second wireless signal) (step S501).

  The wireless signal (second wireless signal) here is, for example, a packet transmitted by the communication terminal 200 to a desired communication partner. Here, the wireless signal is transmitted to an access point to which a BSSID is set. Therefore, the wireless signal transmitted by the communication terminal 200 in step S501 is received by all the access points arranged at positions where the wireless signal can be received. That is, another access point 101 that has not established a communication link with the communication terminal 200 also receives the wireless signal.

  Next, the calculation unit 130 calculates a third index value that is an index value based on the wireless signal received via the first communication unit 110 (Step S502). Note that the third index value is an index value calculated based on a radio signal received from the communication terminal 200 after the access point 100 has established a communication link with the communication terminal 200.

  The other access point 101 calculates a fourth index value that is an index value based on the received wireless signal (step S503). Note that the fourth index value is an index value calculated based on a radio signal received from another communication point 200 by another access point 101 after the access point 100 establishes a communication link with the communication terminal 200.

  Next, the comparing unit 140 compares the communication quality indicated by each of the third index value and the reference index value 170 indicating the predetermined communication quality (step S504). In the present embodiment, reference index value 170 is stored in storage unit 160 in advance.

  Next, when the comparing unit 140 determines that the communication quality indicated by the third index value is lower than the communication quality indicated by the reference index value 170, the control unit 150 sends the second access point 101 The three index values are transmitted via the second communication unit 120 (Step S505).

  Next, the other access points 101 compare the communication quality indicated by the fourth index value calculated in step S403 and the communication quality indicated by each of the third index values received from the access point 100 (step S506).

  Next, when determining that the communication quality indicated by the fourth index value is higher than the communication quality indicated by the third index value, the other access point 101 determines the communication quality indicated by the fourth index value. Is transmitted to the access point 100 (step S507).

  Next, when receiving the communication information from another access point 101 via the second communication unit 120, the control unit 150 transmits the terminal information 210 to the other access point 101 via the second communication unit 120. (Step S508). In step S508, the control unit 150 may transmit the terminal information 210 to the other access point 101 that has transmitted the communication information by unicast via the second communication unit 120. Next to the access point 100, information (for example, a MAC address) indicating an access point responsible for communication with the communication terminal 200 may be transmitted by broadcast. This makes it possible to clarify an access point that is responsible for communication with the communication terminal 200 after the access point 100, so that it is possible to prevent a plurality of access points from sharing communication with the communication terminal 200.

  Further, the control unit 150 stops the communication with the established communication terminal 200 (Step S509).

  Next, the other access point 101 starts communication with the communication terminal 200 by receiving the terminal information 210 from the access point 100, that is, performs communication with the communication terminal 200 (step S510). This allows the other access point 101 to decode, for example, an encrypted wireless signal received from the communication terminal 200, and execute processing included in the wireless signal, for example, transfer of the wireless signal. become able to.

[Effects]
As described above, the access point 100 according to one embodiment of the present invention is one of the communication systems 500 including a plurality of access points that can communicate with each other. The plurality of access points communicate with the communication terminal 200 using the same BSSID. The access point 100 includes a first communication unit 110 for receiving a wireless signal from the communication terminal 200, and a first communication unit 110 that indicates the quality of communication with the communication terminal 200 based on the wireless signal received via the first communication unit 110. The calculating unit 130 for calculating the index value, the second communication unit 120 for receiving the second index value indicating the quality of communication between the other access point 101 and the communication terminal 200, and the first unit calculated by the calculating unit 130. The comparing unit 140 that compares the index value and the second index value received via the second communication unit, and the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value. A control unit that executes an establishment process for establishing a communication link with the communication terminal when the comparison unit determines that the communication link is high.

  According to such a configuration, communication terminal 200 recognizes each of a plurality of access points communicating using the same BSSID as one access point. Therefore, if the communication terminal 200 establishes a communication link with any of the plurality of access points, it can communicate with all of the plurality of access points. Accordingly, the communication terminal 200 does not need to re-establish the communication link even when the access point of the communication destination has changed, so that occurrence of disconnection of communication is suppressed. That is, according to the access point 100, the occurrence of disconnection of the communication link with the communication terminal 200 can be suppressed.

  For example, the access point 100 further includes a storage unit 160 that stores the first index value and the second index value. In the establishment process, when the comparing unit 140 determines that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value, the control unit 150 determines the MAC address of the communication terminal 200 The first connection information including the first index value is transmitted to another access point 101 via the second communication unit 120. In the establishment process, when the second connection information is received from another access point 101 via the second communication unit 120 in the establishment process, the control unit 150 sets the first index value stored in the storage unit 160, 2. The comparing unit 140 compares the second index value included in the connection information with the second index value. In the establishment process, the control unit 150 sets the communication quality indicated by the first index value stored in the storage unit 160 to be higher than the communication quality indicated by the second index value included in the second connection information. If the comparison unit 140 determines that the communication quality is higher, the communication link with the communication terminal 200 is established, and the communication quality indicated by the first index value stored in the storage unit 160 is included in the second connection information. If the comparing unit 140 determines that the communication quality is lower than the communication quality indicated by the second index value, the communication link with the communication terminal 200 is not established.

  According to such a configuration, for example, it is possible to prevent a plurality of access points from erroneously establishing a communication link with the communication terminal 200. Therefore, according to such a configuration, only one of the plurality of access points 100 can easily establish a communication link with the communication terminal 200.

  Further, for example, the control unit 150 starts communication with the communication terminal 200 by receiving terminal information for performing communication with the communication terminal 200 from the communication terminal 200 via the first communication unit 110. If the control unit 150 receives a radio signal from the communication terminal 200 via the first communication unit 110 after the control unit 150 establishes a communication link with the communication terminal 200, the calculation unit 130 A third index value indicating the quality of communication with the communication device 200 is calculated. The comparing unit 140 compares the third index value with a reference index value 170 indicating a predetermined communication quality. When the comparing unit 140 determines that the communication quality indicated by the third index value is lower than the communication quality indicated by the reference index value 170, the control unit 150 assigns the third index value to another access point 101. , Via the second communication unit 120. Further, the control unit 150 transmits, from the other access point 101, communication information indicating that the communication quality between the other access point 101 and the communication terminal 200 is higher than the communication quality indicated by the third index value to the second access point 101. When received via the communication unit 120, terminal information for performing communication with the communication terminal 200 to another access point 101 is transmitted via the second communication unit 120, and communication with the established communication terminal 200 is performed. Stop the communication link.

  According to such a configuration, for example, the access point 100 currently establishing a communication link with the communication terminal 200 can compare the communication quality of the other access points 101 when the communication quality is degraded. . Thus, it is possible to suitably select and execute whether to continue communication with the communication terminal 200 or stop communication by causing another access point 101 to perform communication with the communication terminal 200. Therefore, the communication terminal 200 can suppress the occurrence of communication disconnection when the access point of the communication destination changes, and can maintain high communication quality.

  Further, for example, the calculation unit 130 calculates the received signal strength of the wireless signal received by the first communication unit 110 from the communication terminal 200 as a first index value. In this case, the comparison unit 140 compares the first received signal strength indicated by the first index value with the second received signal strength indicated by the second index value, and determines the higher received signal strength as the communication quality. Is determined to be high. Alternatively, for example, the calculation unit 130 calculates the received signal strength of the wireless signal received by the first communication unit 110 from the communication terminal 200 as the third index value. In this case, the comparing unit 140 compares the third received signal strength indicated by the third index value with the fourth received signal strength indicated by the fourth index value, and determines the higher received signal strength as the communication quality. Is determined to be high.

  According to such a configuration, the access point 100 can compare the communication quality with the other access points 101 using the received signal strength that can be easily detected. Therefore, the occurrence of communication disconnection when the communication terminal 200 changes the access point of the communication destination can be suppressed with a simpler configuration.

  Further, for example, when a plurality of access points constitute the mesh network 410, for example, the calculation unit 130 calculates a metric value as a first index value. Further, in this case, the comparing unit 140 compares the first metric value indicated by the first index value with the second metric value indicated by the second index value, and determines that the lower the metric value is, the lower the communication quality is. Judge as high. Alternatively, for example, the calculation unit 130 calculates the metric value as the third index value. Also, in this case, the comparing unit 140 compares the third metric value indicated by the third index value with the fourth metric value indicated by the fourth index value, and determines that the lower the metric value is, the higher the communication quality is. Judge as high.

  According to such a configuration, the access point 100 can compare the communication quality with the other access points 101 using the metric value that can be easily detected. Therefore, the occurrence of communication disconnection when the communication terminal 200 changes the access point of the communication destination can be suppressed with a simpler configuration.

  Further, for example, when a plurality of access points constitute the mesh network 410, the calculation unit 130 may be configured to perform the calculation based on the reception signal strength of the wireless signal received from the communication terminal 200 via the first communication unit 110 and the metric value. A first index value and a third index value are calculated.

  According to such a configuration, for example, when a difference between one of the metric value and the received signal strength is very small, the access point 100 can compare the difference with the other. Therefore, the communication terminal 200 makes it easier to establish a communication link with an access point having higher communication quality as compared with a case where the communication quality is compared using only the metric value or only the received signal strength, and Also, even when the communication terminal 200 changes the access point of the communication destination, it is possible to make it easier for the access point having higher communication quality to carry out the communication.

  In addition, for example, the calculation unit 130 is calculated from own device position information indicating the position of the access point 100 and terminal position information indicating the position of the communication terminal 200 received from the communication terminal 200 via the first communication unit 110. The distance between the access point 100 and the communication terminal 200 is calculated as a first index value. The comparing unit 140 compares the first distance indicated by the first index value with the second distance indicated by the second index value, and determines that the shorter distance has higher communication quality. Alternatively, for example, the calculation unit 130 may calculate the access point 100 and the communication terminal 100 based on the own device position information and the terminal position information indicating the position of the communication terminal 200 received from the communication terminal 200 via the first communication unit 110. The distance to 200 is calculated as the third index value. Comparing section 140 compares the third distance indicated by the third index value with the fourth distance indicated by the fourth index value, and determines that the shorter distance has higher communication quality.

  According to such a configuration, the access point 100 can compare the quality of communication with the other access points 101 based on the distance between the access point 100 and the communication terminal 200. As described above, by using the position information that can be detected with a simple configuration, the occurrence of communication disconnection when the communication terminal 200 changes the access point of the communication destination can be suppressed with a simpler configuration, and the communication can be performed more easily. Communicate with high quality access points.

  The communication method according to one embodiment of the present invention is a communication method executed by one access point 100 of the communication system 500 including a plurality of access points that can communicate with each other. The communication method according to an aspect of the present invention includes a first communication step of receiving a wireless signal from the communication terminal 200, and a first communication step indicating quality of communication with the communication terminal 200 based on the wireless signal received in the first communication step. A calculation step of calculating an index value, a second communication step of receiving a second index value indicating the quality of communication between the other access point 101 and the communication terminal 200, a first index value calculated in the calculation step, and A comparison step of comparing the second index value received in the second communication step, and a case where the comparison step determines that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value And a control step of executing an establishment process for establishing a communication link with the communication terminal 200.

  According to such a method, the communication terminal 200 can communicate with all of the plurality of access points if a communication link is established with any of the plurality of access points. Accordingly, the communication terminal 200 does not need to re-establish the communication link even when the access point of the communication destination has changed, so that occurrence of disconnection of communication is suppressed. That is, according to the communication method of one embodiment of the present invention, the occurrence of disconnection of the communication link with the communication terminal 200 can be suppressed.

(Other embodiments)
The access point and the like according to the embodiment of the present invention have been described above, but the present invention is not limited to the above embodiment.

  For example, in the above embodiment, the calculation unit 130, the comparison unit 140, and the control unit 150 have been described as being configured by the CPU and the control program. For example, the components of the processing unit such as the calculation unit 130, the comparison unit 140, and the control unit 150 included in the access point 100 may be configured by one or a plurality of electronic circuits. Each of the one or more electronic circuits may be a general-purpose circuit or a dedicated circuit. The one or more electronic circuits may include, for example, a semiconductor device, an integrated circuit (IC), or a large scale integration (LSI). The IC or LSI may be integrated on one chip, or may be integrated on a plurality of chips. Here, the term is referred to as an IC or an LSI, but the term is changed depending on the degree of integration, and may be referred to as a system LSI, a VLSI (very large scale integration), or a ULSI (ultra large scale integration). An FPGA (Field Programmable Gate Array) programmed after manufacturing the LSI can be used for the same purpose.

  Further, general or specific aspects of the present invention may be realized by a system, an apparatus, a method, an integrated circuit, or a computer program. That is, the program includes a first communication step of receiving a wireless signal from the communication terminal 200 and a first index value indicating the quality of communication with the communication terminal 200 based on the wireless signal received in the first communication step. , A second communication step of receiving a second index value indicating the quality of communication between the other access point 101 and the communication terminal 200, a first index value calculated in the calculation step, and a second index value. A comparing step of comparing the second index value received in the communication step; and a communication step when the comparing step determines that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value. And a control step of executing an establishment process for establishing a communication link with the terminal 200.

  Alternatively, the general or specific embodiment of the present invention may be realized by a computer-readable non-transitory recording medium such as an optical disk, an HDD, or a semiconductor memory in which the computer program is stored. Further, the present invention may be realized by any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

  Further, in the above embodiment, the access point and the communication terminal can communicate by wireless communication, but the communication method between the access point and the communication terminal is not particularly limited. For example, wireless communication between an access point and a communication terminal may be performed based on a predetermined wireless communication standard such as Bluetooth (registered trademark), Wi-Fi (registered trademark), or ZigBee (registered trademark).

  As described above, the access point or the like according to one or more aspects has been described based on the embodiment, but the present invention is not limited to this embodiment. Unless departing from the spirit of the present invention, various modifications conceivable by those skilled in the art may be applied to this embodiment, and a form constructed by combining components in different embodiments may be in the range of one or more aspects. May be included within.

  The present invention is applicable to an access point that communicates with a communication terminal, for example, one of a plurality of access points configuring a mesh network.

100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 101, 102 Access point 110 First communication unit 120 Second communication unit 130 Calculation unit 140 Comparison unit 150 Control unit 160 Storage unit 170 Reference index Value 200 communication terminal 210 terminal information 400 external network 410 mesh network 500 communication system

Claims (13)

An access point in a communication system including a plurality of access points capable of communicating with each other,
Each of the plurality of access points communicates with a communication terminal using the same BSSID (Basic Service Set Identifier).
The access point is
A first communication unit for receiving a wireless signal from a communication terminal;
A calculating unit that calculates a first index value indicating the quality of communication with the communication terminal based on the wireless signal received via the first communication unit;
A second communication unit for receiving a second index value indicating the quality of communication between another access point and the communication terminal;
A comparison unit that compares the first index value calculated by the calculation unit, and the second index value received via the second communication unit;
An establishing process for establishing a communication link with the communication terminal when the comparing unit determines that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value; And a control unit for executing the operation. Further, a storage unit for storing the first index value and the second index value,
The control unit, in the establishment process,
If the comparing unit determines that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value, a MAC (Media Access Control) address of the communication terminal and the second Transmitting first connection information including one index value to the other access point via the second communication unit;
When the second connection information including the MAC address of the communication terminal and the second index value is received from the other access point via the second communication unit, the first index stored in the storage unit Value and the second index value included in the second connection information are compared by the comparing unit,
The comparing unit determines that the communication quality indicated by the first index value stored in the storage unit is higher than the communication quality indicated by the second index value included in the second connection information. If it is determined, establish a communication link with the communication terminal,
The comparing unit determines that the communication quality indicated by the first index value stored in the storage unit is lower than the communication quality indicated by the second index value included in the second connection information. The access point according to claim 1, wherein when determining that the communication terminal does not establish a communication link with the communication terminal. The calculating unit, when the control unit establishes a communication link with the communication terminal and receives a wireless signal from the communication terminal via the first communication unit, performs the communication based on the received wireless signal. Calculating a third index value indicating the quality of communication with the terminal;
The comparison unit compares the third index value and a reference index value indicating a predetermined communication quality,
The control unit includes:
If the comparing unit determines that the communication quality indicated by the third index value is lower than the communication quality indicated by the reference index value, the third index value is assigned to the other access point, 2 transmitted via the communication unit,
From the other access point, communication information indicating that the quality of communication between the other access point and the communication terminal is higher than the quality of communication indicated by the third index value, via the second communication unit When receiving, terminal information for carrying out communication with the communication terminal to the other access point is transmitted via the second communication unit, and communication with the established communication terminal is stopped. 3. The access point according to 1 or 2. The calculation unit calculates a reception signal strength of a radio signal received from the communication terminal via the first communication unit as the third index value,
The comparing unit compares the third received signal strength indicated by the third index value with the fourth received signal strength indicated by the fourth index value, and determines that the higher the received signal strength is, the higher the communication quality is. The access point according to claim 3, wherein the access point is determined to be high. The plurality of access points constitute a mesh network,
The calculation unit calculates a metric value as the third index value,
The comparing unit compares a third metric value indicated by the third index value with a fourth metric value indicated by the fourth index value, and determines that a lower metric value is higher in communication quality. The access point according to claim 3. The plurality of access points constitute a mesh network,
The access point according to claim 3, wherein the calculation unit calculates the third index value based on a received signal strength of a wireless signal received from the communication terminal via the first communication unit and a metric value. The calculating unit is configured to calculate the access point calculated based on own device position information indicating a position of the access point and terminal position information indicating a position of the communication terminal received from the communication terminal via the first communication unit. And the distance between the communication terminal and the communication terminal are calculated as the third index value,
The said comparison part compares the 3rd distance shown by the said 3rd index value, and the 4th distance shown by the said 4th index value, and determines that the shorter distance is the quality of communication high. 3. The access point according to 3. The calculation unit calculates a reception signal strength of a radio signal received from the communication terminal via the first communication unit as the first index value,
The comparing unit compares the first received signal strength indicated by the first index value with the second received signal strength indicated by the second index value, and determines that the higher the received signal strength is, the higher the communication quality is. The access point according to claim 1, wherein the access point is determined to be high. The plurality of access points constitute a mesh network,
The calculation unit calculates a metric value as the first index value,
The comparison unit compares a first metric value indicated by the first index value with a second metric value indicated by the second index value, and determines that the lower the metric value is, the higher the communication quality is. The access point according to any one of claims 1 to 7. The plurality of access points constitute a mesh network,
The said calculation part calculates the said 1st index value based on the received signal strength of the radio signal received from the said communication terminal via the said 1st communication part, and a metric value. Access point described in section. The calculating unit is configured to calculate the access point calculated based on own device position information indicating a position of the access point and terminal position information indicating a position of the communication terminal received from the communication terminal via the first communication unit. And the distance between the communication terminal and the communication terminal as the first index value,
The said comparison part compares the 1st distance shown by the said 1st index value, and the 2nd distance shown by the said 2nd index value, and determines that the shorter distance is the quality of communication high. The access point according to any one of claims 1 to 7. A communication method performed by one access point of a communication system including a plurality of access points capable of communicating with each other,
The plurality of access points each communicate with a communication terminal using the same BSSID,
The access point is
A first communication step of receiving a wireless signal from a communication terminal;
A calculating step of calculating a first index value indicating the quality of communication with the communication terminal based on the wireless signal received in the first communication step;
A second communication step of receiving a second index value indicating the quality of communication between another access point and the communication terminal;
A comparison step of comparing the first index value calculated in the calculation step, and the second index value received in the second communication step;
If it is determined in the comparing step that the communication quality indicated by the first index value is higher than the communication quality indicated by the second index value, establishment for establishing a communication link with the communication terminal is established. And a control step of executing a process. A program for causing a computer to execute the communication method according to claim 7.

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