JP2017055165A - Radio communication system and base station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep deterioration down in convenience of a terminal device when radio communication between a base station and the terminal device is disconnected triggered by the base station.SOLUTION: A base station can perform radio communication in accordance with a wireless LAN standard with a terminal device TM. The base station comprises: a measuring unit 40 that measures an RSSI, i.e. strength of a signal received from the terminal device TM; and a determination unit 80 that determines disconnection of communication in accordance with the wireless LAN standard being performed with the terminal device TM on the basis of priority PR, i.e. priority of communication in accordance with the wireless LAN standard at the terminal device TM and the RSSI measured by the measuring unit 40.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a wireless communication system and a base station.

  In recent years, wireless communication systems such as mobile communication systems and wireless local area networks (LANs) have become widespread. In the wireless communication system, in addition to the case where the terminal device disconnects the wireless communication between the base station and the terminal device triggered by the intention of the user of the terminal device, etc. In some cases, the base station is disconnected in order to suppress the communication load of the station. For example, in Patent Document 1, a base station changes a threshold value of an RSSI (Received signal strength indicator) for a signal received from a terminal device in accordance with a communication load in the base station. A technique for suppressing wireless communication between a terminal device and a base station according to a communication load has been proposed.

JP 2007-174543 A

  By the way, when performing wireless communication between the base station and the terminal device, for example, when the terminal device does not have a communication means as an alternative to the wireless communication, or when the user of the terminal device performs communication by the wireless communication. There are cases where there is a situation in which it is not desired to disconnect the wireless communication for the convenience of the terminal device side, such as when it is desired to continue the communication. In such a case, if the base station is triggered and the wireless communication with the terminal device is forcibly disconnected, the convenience of the terminal device may be reduced.

  The present invention has been made in view of the above-described circumstances, and even when the base station disconnects the wireless communication between the base station and the terminal device, the degree of decrease in convenience in the terminal device is reduced. Providing technology that can be suppressed is one of the issues to be solved.

  A base station according to the present invention is a base station that performs communication with a terminal device using a predetermined wireless communication method, a measurement unit that measures the strength of a signal received from the terminal device, and the predetermined wireless communication in the terminal device. A determination unit configured to determine disconnection of communication with the terminal device according to the predetermined wireless communication method based on priority of communication according to the method and the strength of the signal.

  A communication system of the present invention includes a terminal device and a base station that communicates with the terminal device by a predetermined wireless communication method, and the base station measures a strength of a signal received from the terminal device. And a determination unit that determines disconnection of communication with the terminal device based on the predetermined wireless communication method based on a priority of communication using the predetermined wireless communication method in the terminal device and the strength of the signal. It is characterized by comprising.

  According to the present invention, communication disconnection is determined in consideration of not only the strength of the signal measured at the base station but also the priority of communication by the predetermined wireless communication method in the terminal device. For this reason, for example, in consideration of the necessity of continuing communication using a predetermined wireless communication method on the terminal device side and the allowance for disconnection of communication using the predetermined wireless communication method on the terminal device side, The disconnection of the communication can be determined. Therefore, in the present invention, compared with the case of determining the disconnection of communication considering only the strength of the signal received from the terminal device without considering the priority of communication by the predetermined wireless communication method in the terminal device, It is possible to suppress a decrease in convenience in the terminal device.

1 is a diagram showing a configuration of a communication system 100 according to an embodiment of the present invention. It is explanatory drawing for demonstrating the priority PR. It is a block diagram which shows the structure of access point AP. 3 is a sequence diagram for explaining an operation of the communication system 100. FIG. 3 is a sequence diagram for explaining an operation of the communication system 100. FIG. It is a flowchart for demonstrating a communication permission / denial determination process. It is a flowchart for demonstrating a communication disconnection determination process. 10 is a flowchart for explaining communication disconnection determination processing according to Modification 1;

  Embodiments according to the present invention will be described below with reference to the accompanying drawings. The embodiments described below are preferred specific examples of the present invention, and thus various technically preferred limitations are given. However, the scope of the present invention is limited to these unless otherwise specified. It is not limited to the form.

<< A. Embodiment >>
A communication system 100 according to the embodiment will be described with reference to FIGS. 1 to 7.

<< 1. Overview of communication system >>
FIG. 1 is a diagram illustrating a schematic configuration of a communication system 100 according to the embodiment.
As illustrated in FIG. 1, the communication system 100 includes a wireless LAN 1, a mobile communication system 2, and a plurality of terminal devices TM. In the present embodiment, the plurality of terminal devices TM include a terminal device TM1 capable of wireless communication with the wireless LAN 1 and a terminal device TM2 capable of wireless communication with both the wireless LAN 1 and the mobile communication system 2. Suppose.

The wireless LAN 1 is a wireless communication system that can operate according to an IEEE 802.11 wireless LAN standard (an example of a “predetermined wireless communication method”).
As illustrated in FIG. 1, the wireless LAN 1 includes a plurality of access points AP and a communication management system 10. Each access point AP can communicate with the terminal device TM according to the wireless LAN standard. That is, each access point AP is an example of a “base station” that communicates with the terminal device TM by a predetermined wireless communication method. In FIG. 1, for the sake of simplicity, the case where the wireless LAN 1 has three access points AP1 to AP3 is illustrated.

The communication management system 10 includes, for example, an authentication device that authenticates the terminal device TM accessing the wireless LAN 1, a storage device that stores authentication information and other information of the terminal device TM, and communication between each access point AP and the Internet Net. This is a system including a server, a network device, and other elements for the wireless LAN 1 to perform communication with the Internet Net, such as a relay device for relaying.
The terminal device TM is referred to as a Station (STA) in the wireless LAN standard. The terminal device TM can access the Internet Net via the access point AP and the communication management system 10.

The mobile communication system 2 operates in accordance with cellular communication standards (an example of “another wireless communication method”) such as LTE / SAE (Long Term Evolution / System Architecture Evolution) standard included in the 3GPP (Third Generation Partnership Project) standard. It is a possible wireless communication system.
As illustrated in FIG. 1, the mobile communication system 2 includes a plurality of cellular base stations eNB and a communication management system 20. Each cellular base station eNB communicates with the terminal device TM2 in accordance with the cellular communication standard. For the sake of simplicity, FIG. 1 illustrates a case where the mobile communication system 2 includes three cellular base stations eNB.

The communication management system 20 includes, for example, an authentication device that authenticates the terminal device TM2 accessing the cellular base station eNB, a storage device that stores authentication information and other information of the terminal device TM2, and a connection between the cellular base station eNB and the Internet Net. This is a system including a server, a network device, and other elements for the mobile communication system 2 to perform communication with the Internet Net, such as a relay device for relaying communication.
The terminal device TM2 is referred to as User Equipment (UE) in the cellular communication standard. The terminal device TM2 can access the Internet Net via the cellular base station eNB and the communication management system 20.

  The terminal device TM according to the present embodiment generates priority information InfoP and transmits the priority information InfoP to the wireless LAN 1. Here, the priority information InfoP refers to communication according to the wireless LAN standard as compared with communication according to a wireless communication method other than the wireless LAN standard such as the cellular communication standard when the terminal device TM performs wireless communication. This is information indicating the degree of priority of communication according to the wireless LAN standard in the terminal device TM (hereinafter referred to as “priority PR”).

FIG. 2 is an explanatory diagram for explaining the priority PR indicated by the priority information InfoP generated by the terminal device TM.
The priority PR, which is the degree of priority of communication according to the wireless LAN standard in the terminal device TM, depends on whether or not the terminal device TM can perform communication according to another wireless communication standard other than the wireless LAN standard. Determined. Specifically, the priority PR is compared with the case where the terminal device TM can perform communication according to another wireless communication standard when the terminal device TM cannot perform communication according to another wireless communication standard. And set to be higher.
More specifically, in the present embodiment, as illustrated in FIG. 2, the priority PR indicates that the priority is high when the terminal device TM cannot perform communication in accordance with the cellular communication standard. “1” indicating that the priority is low or “2” indicating that the priority is medium when the terminal apparatus TM can perform communication in accordance with the cellular communication standard. Assuming that For example, the priority PR is set to “1” or “2” for the terminal device TM2 shown in FIG. 1, and the priority PR is set to “3” for the terminal device TM1. .

In the case where the terminal device TM can perform communication according to other wireless communication standards other than the wireless LAN standard, that is, when the terminal device TM corresponds to the terminal device TM2, the priority PR is set in the terminal device TM. It is determined according to the degree of restriction on communication according to other wireless communication standards. Specifically, the priority PR is determined to be higher when the restriction on communication according to another wireless communication standard in the terminal device TM2 is strong than when the restriction is weak.
Here, the restrictions on communication according to other wireless communication standards are, for example, the maximum communication amount Tr that is a restriction on the amount of data that can be transmitted and received during a predetermined period (for example, one month) by the communication, and the communication speed by the communication. It is a restriction, a communication cost (contract fee) for the communication, or a combination thereof. That is, the restriction on communication according to other wireless communication standards may be a physical restriction of communication defined by the specifications of the other wireless communication standards or the terminal device TM2, such as communication speed, It may be a restriction defined by a contract concluded with a service provider related to communication according to the other wireless communication standard.
In the present embodiment, it is assumed that the maximum communication amount Tr in communication according to the cellular communication standard is adopted as a restriction on communication according to another wireless communication standard. For example, as illustrated in FIG. 2, the priority PR is set to “2” when the maximum communication amount Tr of cellular communication in the terminal device TM2 is equal to or less than the predetermined communication amount Tr0, and the maximum communication amount Tr is predetermined. It is set to “1” when it is larger than the communication amount Tr0.

In the present embodiment, in the description regarding the determination of the priority PR, whether or not communication according to other wireless communication standards is possible and the degree of restriction on communication according to other wireless communication standards are described as different concepts. However, the fact that communication according to other wireless communication standards is impossible may be considered as the case where the restrictions on communication according to other wireless communication standards are the strongest.
Further, in the present embodiment, the case where the priority PR can take three values “1”, “2”, and “3” is illustrated, but the priority PR has a value larger than three values. It may be one that can be taken, or any value within a predetermined range (for example, a real number of 0 or more and 100 or less).

<< 2. Access point configuration >>
FIG. 3 is a block diagram illustrating the configuration of the access point AP according to the present embodiment.
As illustrated in FIG. 3, the access point AP includes a wireless interface 30, a measurement unit 40, a control unit 50, a storage unit 60, and a wired interface 70.

The wireless interface 30 is a component of the access point AP for performing wireless communication with the terminal device TM. The radio interface 30 includes, for example, a transmission / reception antenna, a reception circuit that converts a received radio signal into an electric signal, and a transmission circuit that converts the electric signal into a radio signal and transmits the radio signal.
The wired interface 70 is a component of the access point AP for performing communication with the communication management system 10. In the present embodiment, a case where the access point AP and the communication management system 10 perform wired communication is illustrated, but the access point AP and the communication management system 10 may perform wireless communication.

  The measurement unit 40 measures the strength of the wireless signal received by the wireless interface 30 and outputs strength information InfoR indicating the measured signal strength. Here, the signal strength indicated by the strength information InfoR is, for example, RSSI (Received signal strength indicator). In the present embodiment, the measurement unit 40 periodically outputs the intensity information InfoR, and temporarily stores the intensity information InfoR in a RAM (Random Access Memory) included in the storage unit 60. However, the measurement unit 40 may directly supply the intensity information InfoR to the control unit 50.

  The storage unit 60 is necessary when the access point AP communicates with the terminal device TM or the communication management system 10, such as the control program for the access point AP, the strength information InfoR, and the priority information InfoP transmitted from the terminal device TM. Various information is stored.

  The control unit 50 is realized by a CPU (central processing unit) (not shown) included in the access point AP executing a control program stored in the storage unit 60 and functioning according to the control program. Consists of blocks. The control unit 50 controls the operation of each unit of the access point AP. Specifically, the control unit 50 controls the operation of each unit of the access point AP so that communication is performed between the access point AP and the terminal device TM, and the access point AP and the communication management system 10 The operation of each part of the access point AP is controlled so that communication is performed between the access points AP.

  Although details will be described later, the control unit 50 stores the priority information acquisition unit 51 for acquiring the priority information InfoP transmitted from the terminal device TM and the measurement unit 40 in the storage unit 60 as shown in FIG. An intensity information acquisition unit 52 that acquires intensity information InfoR. Further, as shown in FIG. 3, the control unit 50 communicates with the terminal device TM based on the priority information InfoP acquired by the priority information acquisition unit 51 and the strength information InfoR acquired by the strength information acquisition unit 52. And a determination unit 80 for executing the determination to give permission to start and the disconnection of communication performed with the terminal device TM.

As illustrated in FIG. 3, the determination unit 80 includes a determination unit 81, a permission procedure execution unit 82, and a cutting procedure execution unit 83.
The determination unit 81 performs determination (hereinafter referred to as “first determination”) as to whether or not the priority information InfoP and the strength information InfoR satisfy a predetermined connection rejection condition. Here, the predetermined connection rejection condition is a condition of values indicated by the priority information InfoP and the strength information InfoR when the access point AP should not start communication with the terminal device TM.
In addition, the determination unit 81 performs determination (hereinafter referred to as “second determination”) as to whether or not the priority information InfoP and the strength information InfoR satisfy a predetermined cutting condition. Here, the predetermined disconnection condition is a condition of values indicated by the priority information InfoP and the strength information InfoR when the access point AP should disconnect communication performed with the terminal device TM.

When the result of the first determination is negative, that is, when the result of the first determination indicates that the start of communication with the terminal device TM is permitted, the permission procedure execution unit 82 causes the terminal device TM to On the other hand, the operation of each part of the access point AP is controlled so as to transmit a signal (probe response frame described later) indicating that the start of communication with the access point AP is permitted.
When the result of the second determination is affirmative, that is, when the result of the second determination indicates that the communication performed with the terminal device TM should be disconnected, the disconnection procedure execution unit 83 The execution of the procedure for disconnecting the communication with the terminal device TM is controlled.

<< 3. Operation of communication system >>
Next, an example of operations of the wireless LAN 1 and the terminal device TM according to the present embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram illustrating an operation sequence of the communication system 100 when the access point AP starts communication with the terminal device TM. FIG. 5 is a diagram illustrating an operation sequence of the communication system 100 when the access point AP disconnects communication performed with the terminal device TM.

As shown in FIG. 4, when starting communication with the wireless LAN 1, the terminal device TM first broadcasts a Probe Request frame that is a frame for finding an access point AP communicable with the terminal device TM. (S10).
The terminal device TM according to the present embodiment transmits the priority information InfoP to the access point AP by adding the priority information InfoP to the Frame body of the Probe Request frame broadcasted in step S10. Note that the terminal device TM according to the present embodiment generates the priority information InfoP in advance before starting the process of step S10, and stores the generated priority information InfoP in the storage unit included in the terminal device TM. The priority information InfoP may be generated in the process of step S10.

When receiving a Probe Request frame from the terminal device TM, the access point AP executes a communication permission / inhibition determination process including a first determination (S11).
When the result of the first determination is negative in the communication permission determination process at step S11, that is, when the result of the first determination indicates that the start of communication with the terminal device TM is permitted, the access point AP In this case, a Probe Response frame that is a frame indicating that the terminal device TM that has transmitted the Probe Request frame is permitted to start communication with the access point AP is transmitted. On the other hand, when the result of the first determination is affirmative in the communication permission / inhibition determination process in step S11, that is, the access point AP should reject the start of communication with the terminal device TM. Is not transmitted, the probe response frame is not transmitted, and the start of communication with the terminal device TM is rejected. The communication permission / inhibition determination process in step S11 will be described in detail separately.

When receiving the Probe Response frame, the terminal device TM selects an access point AP that is a connection destination candidate (S12).
Specifically, when the terminal apparatus TM receives a signal including a probe response frame from a plurality of access points AP in step S12, for example, based on the signal strength of the received signal, the plurality of access points AP. One access point AP to be a connection candidate is selected from the above. On the other hand, when the terminal device TM receives a Probe Response frame from one access point AP in step S12, the terminal device TM selects the access point AP as a connection candidate.

Next, the terminal device TM, the access point AP selected by the terminal device TM in step S12, and the communication management system 10 execute a procedure for establishing a connection between the terminal device TM and the access point AP ( S13).
The outline of the procedure executed in step S13 is as follows. That is, in step S13, first, the terminal apparatus TM transmits an ANQP Query to the access point AP (S131). The access point AP that has received the ANQP Query transmits an ANQP Response to the terminal device TM that has transmitted the ANQP Query (S132). The terminal device TM that has received the ANQP Response transmits an authentication request message to the access point AP (S133). Here, the authentication request message in step S133 may include a message such as Association Request or Authentication Request. The access point AP that has received the authentication request message transmits an authentication request message by Radius, for example, to the communication management system 10 (S134). The communication management system 10 that has received the authentication request message authenticates the terminal device TM using authentication information stored in a storage device provided in the communication management system 10, and sends an authentication result message indicating the result of the authentication to the access point. Transmit to AP (S135). The access point AP that has received the authentication result message transmits an authentication result message indicating the authentication result by the communication management system 10 to the terminal device TM (S136). When the authentication of the terminal device TM by the communication management system 10 is successful, the terminal device TM and the access point AP are exchanged with, for example, an encryption key by 4-way-handshake, and the terminal device TM and the access point AP. (S137).

After the connection between the terminal device TM and the access point AP is established, the terminal device TM communicates with the Internet Net via the access point AP and the communication management system 10 (S20).
Specifically, in step S20, as illustrated in FIG. 5, when the terminal apparatus TM transmits a Data frame to the access point AP (S201), the access point AP transmits an Ack frame to the terminal apparatus TM. Is transmitted (S202). Then, the access point AP transmits the data stored in the body of the Data frame received in step S201 to the communication destination server of the terminal device TM on the Internet Net via the communication management system 10. (S203). Thereafter, when the access point AP receives data transmitted from the communication destination server or the like of the terminal device TM via the communication management system 10 (S204), the access point AP generates the Data frame generated based on the data. Is transmitted to the terminal device TM (S205). When receiving the Data frame from the access point AP, the terminal device TM transmits an Ack frame to the access point AP (S206). In this way, the terminal device TM communicates with a communication destination server on the Internet Net via the wireless LAN 1 (access point AP and communication management system 10).

When the access point AP receives an Ack frame from the terminal device TM in step S206, the access point AP executes a communication disconnection determination process including the second determination (S21).
In the communication disconnection determination process in step S21, the access point AP disconnects the communication in which the second determination result is positive, that is, the second determination result is communicated with the terminal device TM. When indicating the power, a disassociation frame that is a frame indicating disconnection of communication with the access point AP is transmitted to the terminal device TM. In this case, the terminal device TM that has received the disassociation frame transmits an Ack frame to the access point AP, and the communication between the terminal device TM and the access point AP is disconnected (S22).
On the other hand, in the communication disconnection determination process in step S21, the access point AP performs communication in which the second determination result is negative, that is, the second determination result is communicated with the terminal device TM. When indicating that it should be continued, the disassociation frame is not transmitted, and the start of communication with the terminal device TM is continued. The communication disconnection determination process in step S21 will be described in detail separately.

<< 4. Communication permission / refusal decision processing >>
Next, communication permission / inhibition determination processing will be described with reference to FIG.

  FIG. 6 is a flowchart illustrating an example of the operation of the access point AP when the communication permission / inhibition determination process in step S11 is executed. The communication permission / inhibition determination process is started when the access point AP receives the Probe Request frame transmitted by the terminal device TM in step S10.

In the communication permission / inhibition determination process, the control unit 50 of the access point AP first determines whether or not the communication load of the access point AP is equal to or greater than a predetermined load (S30).
When the determination result of step S30 is negative, the control unit 50 acquires the priority information InfoP from the Probe Request frame received from the terminal device TM (S31). The control unit 50 functions as the priority information acquisition unit 51 when executing the process of step S31.
Further, the control unit 50 acquires the intensity information InfoR from the storage unit 60 (S32). The control unit 50 functions as the intensity information acquisition unit 52 when executing the process of step S32.

  Next, the control unit 50 determines whether or not the RSSI indicated by the strength information InfoR is equal to or less than the predetermined strength α (S33). The predetermined intensity α is a predetermined value that is larger than the minimum value that can be taken by the RSSI indicated by the intensity information InfoR and smaller than the maximum value. When the determination result in step S33 is affirmative, the control unit 50 determines whether or not the priority PR indicated by the priority information InfoP is equal to or less than a predetermined value β (S34). The predetermined value β is a predetermined value that is larger than the minimum value that the priority PR can take and smaller than the maximum value. The control unit 50 functions as the determination unit 81 when executing at least one of steps S33 and S34.

When the determination result in step S34 is affirmative, the control unit 50 considers that a predetermined connection rejection condition is satisfied, and does not transmit a Probe Response frame to the terminal device TM (that is, the terminal device). The communication permission / refusal decision processing is terminated (S35).
That is, in the present embodiment, the first determination includes two determinations, that is, the determination in step S33 and the determination in step S34. In the present embodiment, the predetermined connection refusal condition is that the RSSI satisfies “RSSI ≦ α” and the priority PR satisfies “PR ≦ β”. Note that, as shown in FIG. 6, the control unit 50 ends the communication permission / inhibition determination process without transmitting the Probe Response frame to the terminal device TM even when the determination result in step S30 is affirmative.

  On the other hand, when the determination result in step S33 or S34 is negative, that is, when the result of the first determination indicates that the start of communication with the terminal device TM is permitted, the control unit 50 performs the terminal device TM. The operation of each part of the access point AP is controlled so that the Probe Response frame is transmitted (S36). In addition, the control part 50 functions as the permission procedure execution part 82, when performing the process of step S36.

  And the control part 50 stores the priority information InfoP acquired by step S31 in the memory | storage part 60 (S37), and complete | finishes a communication permission / denial determination process. Note that, when the priority information InfoP is stored in the storage unit 60, the control unit 50, after a predetermined time has elapsed from the storage, or when communication with the terminal device TM is executed, after the communication is disconnected. After a predetermined time has elapsed, the priority information InfoP is deleted from the storage unit 60.

  In this way, the control unit 50 determines to give the terminal device TM permission to start communication when executing at least part of the processing of steps S33 to S36 enclosed by a broken line in the figure, or It functions as a determination unit 80 that determines that permission is not given.

<< 5. Communication disconnection decision processing >>
Next, communication disconnection determination processing will be described with reference to FIG.

  FIG. 7 is a flowchart showing an example of the operation of the access point AP when the communication disconnection determination process in step S21 is executed. The communication disconnection determination process is started when the access point AP receives the Ack frame transmitted by the terminal device TM in step S206.

In the communication disconnection determination process, the control unit 50 of the access point AP acquires the priority information InfoP stored in the storage unit 60 in step S37 (S41).
Next, the control unit 50 executes at least a part of steps S42, S43, and S44 shown in FIG. 7, and these processes are the same as steps S32, S33, and S34 shown in FIG. Therefore, explanation is omitted. The control unit 50 functions as the intensity information acquisition unit 52 when executing the process of step S42, and functions as the determination unit 81 when executing at least one of steps S43 and S44.

When the determination result in step S44 is affirmative, the control unit 50 considers that the predetermined disconnection condition is satisfied, and sets each part of the access point AP so that the disassociation frame is transmitted to the terminal device TM. The operation is controlled (S45), and then the communication disconnection determination process is terminated.
In other words, in the present embodiment, the second determination includes two determinations, that is, the determination in step S43 and the determination in step S44. In the present embodiment, the predetermined disconnection condition is that the RSSI satisfies “RSSI ≦ α” and the priority PR satisfies “PR ≦ β”. The control unit 50 functions as the cutting procedure execution unit 83 when executing the process of step S45.

  On the other hand, when the determination result in step S43 or S44 is negative, that is, when the result of the second determination indicates that communication with the terminal device TM should be continued, the control unit 50 causes the terminal device TM to On the other hand, the probe response frame is not transmitted (S46), and the communication disconnection determination process is terminated while the communication with the terminal device TM is continued.

  As described above, the control unit 50 determines whether or not to disconnect the communication with the terminal device TM or performs the communication with the terminal device TM when executing the processes of steps S43 to S66 surrounded by a broken line in the figure. It functions as a decision unit 80 that decides to continue.

<< 6. Conclusion of embodiment >>
As described above, when the access point AP according to the present embodiment receives a Probe Request frame from the terminal device TM, it determines whether or not to transmit a Probe Response frame based on the RSSI indicated by the strength information InfoR. decide. Therefore, in the present embodiment, it is possible to prevent communication with the terminal device TM from being started when the quality of communication with the terminal device TM is expected to be low. As a result, it is possible to suppress a decrease in communication quality.

Further, when the access point AP according to the present embodiment receives the Probe Request frame from the terminal device TM, the access point AP determines whether to transmit the Probe Response frame based on the priority PR indicated by the priority information InfoP.
Therefore, when the wireless communication possible in the terminal device TM is only communication according to the wireless LAN standard, the communication between the terminal device TM and the wireless LAN 1 can be preferentially started. For this reason, it is possible to prevent the occurrence of a situation in which the terminal device TM cannot perform any wireless communication.
Further, when there are strong restrictions on communication according to other wireless communication standards, such as when the maximum communication amount Tr of communication according to the cellular communication standard performed by the terminal device TM is small, communication between the terminal device TM and the wireless LAN 1 is performed. Can be preferentially started. That is, when the user of the terminal device TM desires communication according to the wireless LAN standard and does not desire communication according to another wireless communication standard, there is a possibility that communication according to another wireless communication standard is performed. Can be kept low.

  Whether the access point AP according to the present embodiment transmits a disassociation frame based on RSSI indicated by the strength information InfoR when receiving an Ack frame from the terminal device TM after transmitting the data frame to the terminal device TM. Decide whether or not. Therefore, according to the present embodiment, communication with the terminal device TM can be disconnected when the quality of communication with the terminal device TM is expected to be low. As a result, it is possible to suppress a decrease in communication quality.

In addition, when the access point AP according to the present embodiment receives an Ack frame from the terminal device TM after transmitting the Data frame to the terminal device TM, the access point AP transmits a disassociation frame based on the priority PR indicated by the priority information InfoP. Decide whether or not to do.
Therefore, according to the present embodiment, when the wireless communication possible in the terminal device TM is only communication in accordance with the wireless LAN standard, the communication between the terminal device TM and the wireless LAN 1 is forcibly disconnected. Can be avoided. That is, when the terminal device TM cannot perform communication according to another wireless communication standard that is an alternative to communication according to the wireless LAN standard, it is avoided that the communication according to the wireless LAN standard is forcibly disconnected. can do. For this reason, it is possible to prevent the occurrence of a situation in which the terminal device TM cannot perform any wireless communication.
Further, when the restriction on communication according to other wireless communication standards in the terminal device TM is strong, the communication between the terminal device TM and the wireless LAN 1 can be preferentially continued. In other words, in the case where it is assumed that the user of the terminal device TM does not wish to communicate according to another wireless communication standard, it is possible to prevent a situation in which the use of communication conforming to another wireless communication standard is forced. can do.

  As described above, in this embodiment, the start and disconnection of communication is determined based on the priority PR in the terminal device TM in addition to the RSSI strength on the access point AP side. For this reason, it becomes possible to aim at coexistence with suppression of the fall of communication quality, and the suppression of the fall of the convenience in terminal device TM.

<< B. Modification >>
Each of the above forms can be variously modified. Specific modifications are exemplified below. Two or more aspects arbitrarily selected from the following examples can be appropriately combined within a range that does not contradict each other. In addition, about the element which an effect | action and a function are equivalent to embodiment in the modification illustrated below, the code | symbol referred by the above description is diverted and each detailed description is abbreviate | omitted suitably.

<< Modification 1 >>
In the above-described embodiment, the first determination that determines whether or not the predetermined connection rejection condition is satisfied based on the RSSI indicated by the strength information InfoR and the priority PR indicated by the priority information InfoP, However, the present invention is not limited to such an embodiment, and the first determination and the second determination are as follows. It may be executed based on information other than the strength information InfoR and the priority information InfoP.

  FIG. 8 is a flowchart showing an example of the operation of the access point AP in the communication disconnection determination process according to this modification. Compared with the communication disconnection determination process according to the embodiment illustrated in FIG. 7, the communication disconnection determination process according to the present modification illustrated in FIG. 8 is executed in steps S <b> 50 to S <b> 52 and steps S <b> 43 and S <b> 44. The difference is that the process is not executed, but the other points are the same.

As shown in FIG. 8, in the communication disconnection determination process, the control unit 50 according to the present modification first acquires information indicating the communication load of the access point AP (S50). Then, after executing the processing of steps S41 and S42, a connection index value Q is generated based on the RSSI indicated by the strength information InfoR, the priority PR indicated by the priority information InfoP, and the communication load (S51).
The connection index value Q is a value representing the degree of preference for executing communication between the access point AP and the terminal device TM in consideration of the viewpoints of both the access point AP and the terminal device TM. Any value can be used. In the present modification, as an example, the connection index value Q is determined so as to increase as the RSSI increases, increase as the priority PR increases, and increase as the communication load decreases. I will do it.

Next, the control unit 50 according to the present modification determines whether or not the connection index value Q is equal to or less than the predetermined value γ (S52). If the determination result of step S52 is affirmative, the process proceeds to step S45. If the decision result in the step S52 is negative, the process advances to a step S46. The predetermined value γ is a predetermined value that is larger than the minimum value that can be taken by the connection index value Q and smaller than the maximum value.
As described above, the control unit 50 according to the present modification functions as the determination unit 81 by executing the process of step S52. In the present modification, the determination in step S52 corresponds to the second determination. In the present modification, the connection index value Q satisfying “Q ≦ γ” corresponds to a predetermined cutting condition.

  Although illustration is omitted, in the present modification, the first determination executed in the communication permission / rejection determination process is the same as the second determination according to the present modification. That is, in this modification, the determination in step S52 also corresponds to the first determination, and that the connection index value Q satisfies “Q ≦ γ” also corresponds to the predetermined connection rejection condition.

<< Modification 2 >>
In the embodiment and the modification described above, the predetermined connection rejection condition and the predetermined disconnection condition have the same contents. However, the present invention is not limited to such an aspect, and the predetermined connection rejection condition and the predetermined disconnection condition are the same. The content may be different from the cutting conditions.
For example, the predetermined strength α, the predetermined value β, or the predetermined value γ used in the communication permission determination process and the predetermined strength α, the predetermined value β, or the predetermined value γ used in the communication disconnection determination process are set as different values. Also good.
For example, the predetermined strength α, the predetermined value β, and the predetermined value γ used in the communication permission determination process and the communication disconnection determination process are values that change according to the communication load when the process is executed, for example, the communication load It is good also as a value which becomes large as becomes high.

<< Modification 3 >>
In the embodiment and the modification described above, the terminal device TM adds the priority information InfoP to the Probe Request frame and transmits it to the access point AP. However, the present invention is not limited to such a mode. The TM may transmit the priority information InfoP to the access point AP by adding the priority information InfoP to a message other than the Probe Request frame. For example, the terminal device TM may add the priority information InfoP to the access point AP by adding it to various frames such as ANQP Query, Association Request, or Authentication Request transmitted in step S13.

<< Modification 4 >>
In the embodiment and the modification described above, the wireless LAN 1 stores the priority information InfoP in the storage unit 60 included in the access point AP. However, the present invention is not limited to such an aspect, and the wireless LAN 1 The priority information InfoP may be stored in a storage device included in the communication management system 10.
In this case, for example, the access point AP may add the priority information InfoP transmitted from the terminal device TM to the authentication request message by Radius in step S134 and transmit it to the communication management system 10. In this case, the wireless LAN 1 does not manage the priority information InfoP only during the period in which the communication between the access point AP and the terminal device TM continues as in the above-described embodiment, but the access point AP and the terminal The priority information InfoP may be continuously managed even after the communication with the device TM is disconnected. In this case, the access point AP may acquire the priority information InfoP from the communication management system 10 when the Probe Request frame is transmitted from the terminal device TM.

<< Modification 5 >>
In the embodiment and the modification described above, the wireless LAN standard is exemplified as the predetermined wireless communication method, and the cellular communication standard is exemplified as the other wireless communication method. However, the present invention is limited to such an aspect. The predetermined wireless communication method is not a standard defined by a wireless LAN standard, a cellular communication standard, or other wireless access technology (for example, WiMAX defined in IEEE 802.16-2004 and IEEE 802.16e). Any one of the wireless communication systems selected from the wireless communication systems exemplified above may be used. In this case, the other wireless communication method may be a wireless communication method different from the predetermined wireless communication method.
In the embodiment and the modification described above, the communication system 100 can perform communication using two wireless communication methods. However, the present invention is not limited to such an aspect. Communication using the above wireless communication method may be possible. In this case, one wireless communication method selected from three or more wireless communication methods is set as a predetermined wireless communication method, and one or two or more wireless communication methods other than the predetermined wireless communication method are used. The communication method may be another wireless communication method.

<< Modification 6 >>
In the embodiment and the modification described above, the access point AP transmits the disassociation frame when disconnecting the communication with the terminal device TM, but the present invention is not limited to such an aspect, and the access point AP When the communication with the communication is disconnected, another signal for disconnecting the communication may be transmitted instead of the disassociation frame. For example, a mode may be used in which “Status codes” is set to “REFUSED” in a response frame transmitted from the access point AP such as a Deauthentication frame or an Association Response.

<< Modification 7 >>
In the embodiment and the modification described above, each function executed by the CPU may be executed by hardware instead of the CPU, and programmable logic such as FPGA (Field Programmable Gate Array) and DSP (Digital Signal Processor), for example. May run on the device.

DESCRIPTION OF SYMBOLS 1 ... Wireless LAN, 2 ... Mobile communication system, 10 ... Communication management system, 20 ... Communication management system, 30 ... Wireless interface, 40 ... Measurement part, 50 ... Control part, 51 ... Priority information acquisition part, 52 ... Strength information Acquiring unit, 60 ... storage unit, 70 ... wired interface, 80 ... determining unit, 81 ... determining unit, 82 ... permitting procedure executing unit, 83 ... disconnection procedure executing unit, 100 ... communication system, AP ... access point, eNB ... cellular Base station, TM ... terminal equipment.

Claims (8)

A base station that communicates with a terminal device by a predetermined wireless communication method,
A measurement unit for measuring the strength of a signal received from the terminal device;
Based on the priority of communication by the predetermined wireless communication method in the terminal device and the strength of the signal,
A determination unit that determines disconnection of communication with the terminal device by the predetermined wireless communication method;
Comprising
A base station characterized by that. The determination unit
When the priority is not more than a predetermined value and the intensity of the signal is not more than a predetermined intensity,
Determining disconnection of the communication;
The base station according to claim 1, wherein: The priority is
The terminal device is a value determined according to whether or not communication by another wireless communication method different from the predetermined wireless communication method is possible.
The base station according to claim 1 or 2, characterized by the above. The priority is
It is a value determined according to the degree of restriction on communication by the other wireless communication method,
The base station according to claim 3, wherein: The terminal device
Information indicating the priority is added to a probe request frame and transmitted to the base station;
The base station according to any one of claims 1 to 4, characterized in that: The determination unit
Based on the strength of the signal measured by the measurement unit when receiving the probe request frame transmitted from the terminal device, and the priority added to the probe request frame,
Determining not to communicate with the terminal device by the predetermined wireless communication method;
The base station according to claim 5, wherein: The determination unit
Determining disconnection of the communication based on the priority, the strength of the signal, and the communication load of the base station;
The base station according to any one of claims 1 to 6, characterized in that: A terminal device;
A base station that communicates with the terminal device by a predetermined wireless communication method;
With
The base station
A measurement unit for measuring the strength of a signal received from the terminal device;
Based on the priority of communication by the predetermined wireless communication method in the terminal device and the strength of the signal,
A determination unit that determines disconnection of communication with the terminal device by the predetermined wireless communication method;
Comprising
A communication system characterized by the above.

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