Terminal, communication method and recording medium

Abstract

The present invention provides a terminal, a communication method and a recording medium. The terminal (20) comprises: a measuring unit (203) for measuring at least one of a delay when a wireless signal is sent to an access point and a fluctuation of the wireless signal; a data processing unit (201) for generating information including the measurement result; and a wireless communication processing unit (202) for sending the information to the access point.

Description

Technical Field

[0001] Embodiments relate to a terminal, a communication method, and a recording medium. Background Art

[0002] Wireless LAN access points and terminals use CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) access channels to send wireless signals. In CSMA / CA, access points and terminals wait for a time specified by access parameters and send wireless signals after confirming through carrier sensing that other terminals are not using the channel.

[0003] As one of the priority control methods in wireless LAN, EDCA (Enhanced Distribution Channel Access) is defined. In EDCA, traffic from the upper layer is classified into four access categories (AC), namely, AC_VO (Voice), AC_VI (Video), AC_BE (Best effort), and AC_BK (Background). Moreover, in EDCA, CSMA / CA is performed for each access category. In EDCA, access parameters are allocated so that the transmission of wireless signals is relatively prioritized in the order of AC_VO, AC_VI, AC_BE, and AC_BK.

[0004] Prior art literature

[0005] Non-patent literature

[0006] Non-patent document 1: IEEE Std 802.11-2016, “10.22.2 HCF contention based channel access (EDCA)”, 7 December 2016 Summary of the invention

[0007] Problems to be solved by the invention

[0008] Relative prioritization between traffic flows is performed through EDCA. Here, for example, RTA (Real-Time Application) such as online games and industrial robot control has absolute delay and fluctuating request conditions for each application. It is not clear whether RTA can be used in only relative prioritization, or whether control can be performed to enable RTA to be used.

[0009] Means for solving problems

[0010] A terminal of one embodiment includes a measuring unit, a data processing unit, and a wireless signal processing unit. The measuring unit measures at least one of a delay when a wireless signal is sent to an access point and a fluctuation of the wireless signal. The data processing unit generates information including the measurement result. The wireless signal processing unit sends the information to the access point.

[0011] According to the embodiment, even when there is an absolute delay or fluctuating request condition, it is possible to provide information for determining whether or not the request condition is met. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram showing a structure of an example of a communication system according to an embodiment.

[0013] Figure 2 FIG. 1 is a diagram showing a hardware configuration of an example of an access point.

[0014] Figure 3 This is a diagram showing a hardware configuration of an example of a terminal.

[0015] Figure 4 This is a diagram showing the processing of the MAC (Media Access Control) layer when an access point communicates with a terminal.

[0016] Figure 5 is a functional block diagram of an access point.

[0017] Figure 6 It is a functional block diagram of the terminal.

[0018] Fig. 7A This is a diagram of the first example of the format of the reported MAC payload.

[0019] Figure 7B This is a diagram showing a second example of the format of the reported MAC payload.

[0020] Fig. 8A This is a diagram showing a first example of an access point requesting a report using an Action frame.

[0021] Figure 8B This is a diagram showing a second example of an access point requesting a report using an Action frame.

[0022] Fig.9A This is a diagram showing a first example of an access point requesting a report using a management frame or a control frame.

[0023] Fig. 9B This is a diagram showing a second example of an access point requesting a report using a management frame or a control frame.

[0024] Fig.10 This is a flowchart showing the transmission processing of an example of a terminal.

[0025] Fig.11 This is a flowchart showing the report processing in the terminal.

[0026] Fig.12 FIG. 1 is a flowchart showing a reception process of an example access point.

[0027] Fig.13 is a flowchart showing the reporting process in an access point.

[0028] Fig.14 It is a figure which shows a modification example. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments will be described based on the drawings. Figure 1 1 is a diagram showing a configuration of an example of a communication system according to an embodiment. The communication system 1 includes an access point 10 and a terminal 20. The access point 10 performs wireless LAN communication with a terminal within a predetermined service area. Figure 1 Although not shown, communication between the terminals 20 is also possible.

[0030] Figure 2 1 is a diagram showing an example of a hardware configuration of the access point 10. The access point 10 is an access point (AP) for the terminal 20. The access point 10 is not limited to a fixed one, and may be mounted on a mobile body.

[0031] The access point 10 includes a processor 11 , a ROM (Read Only Memory) 12 , a RAM (Random Access Memory) 13 , a wireless module 14 , and a router module 15 .

[0032] The processor 11 is a processing device that controls the overall control of the access point 10. The processor 11 is, for example, a CPU (Central Processing Unit). The processor 11 is not limited to a CPU. In addition, an ASIC (Application Specific IC) or the like may be used instead of a CPU. In addition, the processor 11 may be not one but two or more.

[0033] The ROM 12 is a read-only storage device and stores firmware and various programs necessary for the operation of the access point 10 .

[0034] The RAM 13 is a storage device that can be written to arbitrarily. The RAM 13 is used as a work area for the processor 11 and temporarily stores firmware and the like stored in the ROM 12 .

[0035] The wireless module 14 is a module configured to perform processing required for wireless LAN communication. The wireless module 14 forms a MAC frame based on data forwarded from the processor 11, for example, and converts the formed MAC frame into a wireless signal and transmits it to the terminal 20. In addition, the wireless module 14 receives a wireless signal from the terminal 20, reads data from the received wireless signal, and forwards it to the processor 11, for example.

[0036] The router module 15 is provided so that the access point 10 can communicate with a server (not shown) via a network, for example. In addition, the access point 10 may not necessarily have the router module 15. The access point 10 may be configured to access a router provided outside the access point 10 through wireless communication or wired communication and connect to the network via the router.

[0037] Figure 3 1 is a diagram showing an example of a hardware configuration of the terminal 20. The terminal 20 is a terminal device (station) such as a smartphone. The terminal 20 may be a mobile terminal, a terminal mounted on a mobile body, or a fixed terminal.

[0038] The terminal 20 includes a processor 21 , a ROM 22 , a RAM 23 , a wireless module 24 , a display 25 , and a storage 26 .

[0039] The processor 21 is a processing device that performs overall control of the terminal 20. The processor 21 is, for example, a CPU. The processor 21 is not limited to a CPU. In addition, an ASIC or the like may be used instead of a CPU. In addition, the processor 21 may be not one but two or more.

[0040] The ROM 22 is a read-only storage device and stores firmware and various programs necessary for the operation of the terminal 20 .

[0041] The RAM 23 is a storage device that can be written to arbitrarily. The RAM 23 is used as a work area for the processor 21 and temporarily stores firmware and the like stored in the ROM 22 .

[0042] The wireless module 24 is a module configured to perform processing required for wireless LAN communication. The wireless module 24 configures a MAC frame for wireless communication based on data transferred from the processor 21, for example, and converts the configured MAC frame into a wireless signal and transmits it to the access point 10. In addition, the wireless module 24 receives a wireless signal from the access point 10, reads data from the received wireless signal, and transfers it to the processor 21, for example.

[0043] The display 25 is a display device that displays various screens. The display 25 may be a liquid crystal display, an organic EL display, etc. In addition, the display 25 may also include a touch panel.

[0044] The storage 26 is a storage device such as a hard disk. The storage 26 stores various applications executed by the processor 21, for example.

[0045] Figure 4 This is a diagram showing the processing of the MAC (Media Access Control) layer when the access point 10 communicates with the terminal 20. Figure 4 , both the processing on the transmission side and the processing on the reception side are shown. When the wireless module of one of the access point 10 and the terminal 20 performs the processing on the transmission side, the wireless module of the other performs the processing on the reception side. In the following example, the wireless modules on the transmission side and the reception side are described without distinction.

[0046] First, the processing on the transmission side is described. In step S10, the wireless module performs A-MSDU aggregation. Specifically, the wireless module combines multiple data input from the application layer and other higher layers to generate an A-MSDU (Aggregate-MAC service data unit).

[0047] In step S11, the wireless module allocates a sequence number (SN) to the A-MSDU. The sequence number is a unique number used to identify the A-MSDU.

[0048] In step S12, the wireless module segments (fragments) the A-MSDU into a plurality of MPDUs (MAC protocol data units).

[0049] In step S13, the wireless module encrypts each MPDU to generate an encrypted MPDU.

[0050] In step S14, the wireless module adds a MAC header and an error detection code (FCS) to each encrypted MPDU. The error detection code is, for example, a CRC (Cyclic Redundancy Check) code.

[0051] In step S15, the wireless module performs A-MPDU aggregation. Specifically, the wireless module combines multiple MPDUs to generate an A-MPDU (Aggregate-MAC protocol data unit) as a MAC frame.

[0052] After step S15 , the wireless module performs physical layer processing on the MAC frame. That is, the wireless module performs modulation processing on the MAC frame, generates a wireless signal, and sends the wireless signal to the access point 10 .

[0053] Next, the processing on the receiving side is described. If a wireless signal is received, the wireless module performs physical layer processing and recovers the MAC frame from the wireless signal. Figure 4 The MAC layer processing is shown.

[0054] In step S20 , the wireless module deaggregates the A-MPDU. Specifically, the wireless module divides the A-MPDU into units of MPDUs.

[0055] In step S21, the wireless module performs error detection. For example, the wireless module determines whether the reception of the wireless signal is successful through CRC. When the reception of the wireless signal fails, the wireless module can make a retransmission request. At this time, the wireless module can also request retransmission in units of MPDU. On the other hand, when the reception of the wireless signal is successful, the wireless module performs the following processing.

[0056] In step S22, the wireless module performs address detection. At this time, the wireless module determines whether the MPDU sent is sent to itself through the address recorded in the MAC header of each MPDU. If it is not sent to itself, the wireless module does not perform the following processing. If it is sent to itself, the wireless module performs the following processing.

[0057] In step S23, the wireless module decrypts the encrypted MPDU.

[0058] In step S24, the wireless module defragments the MPDU. In other words, the wireless module recovers the A-MSDU from the multiple MPDUs.

[0059] In step S25, the wireless module deaggregates the A-MSDU. Specifically, the wireless module restores the A-MSDU to data in MSDU units.

[0060] After step S25, the wireless module outputs the data to a higher layer of the MAC layer, such as the application layer.

[0061] Figure 5 1 is a functional block diagram of the access point 10. The access point 10 includes a data processing unit 101, a wireless signal processing unit 102, and a management unit 103. The data processing unit 101, the wireless signal processing unit 102, and the management unit 103 are implemented by the processor 11 and the wireless module 14, for example.

[0062] The data processing unit 101 forms a MAC frame based on data transferred from a server on the network, for example. In addition, the data processing unit 101 restores data based on the MAC frame transferred from the wireless signal processing unit 102. The data includes a report sent from the terminal 20.

[0063] The wireless signal processing unit 102 performs processing for sending or receiving wireless signals. For example, the wireless signal processing unit 102 converts the MAC frame formed by the data processing unit 101 into a wireless signal, and sends the wireless signal to the terminal 20. In addition, the wireless signal processing unit 102 receives a wireless signal from the terminal 20, extracts a MAC frame from the received wireless signal, and forwards it to the data processing unit 101.

[0064] The management unit 103 manages the report sent from the terminal 20. For example, the management unit 103 stores the report in advance and uses the information stored in the report when necessary. The report includes information related to the delay or fluctuation of the transmission of the wireless signal in the terminal 20. The details of the report will be described later.

[0065] Here, the wireless signal processing unit 102 may be configured to transmit a wireless signal, for example, by EDCA. In this case, the wireless signal processing unit 102 has transmission queues AC_VO, AC_VI, AC_BE, and AC_BK for each access category (AC). The transmission queue AC_VO is a queue for holding MAC frames classified as VO (Voice). The transmission queue AC_VI is a queue for holding MAC frames classified as VI (Video). The transmission queue AC_BE is a queue for holding MAC frames classified as BE (Besteffort). The transmission queue AC_BK is a queue for holding MAC frames classified as BK (Background).

[0066] The wireless signal processing unit 102 maps the MAC frame transferred from the data processing unit 101 to any one of the four access types according to the type of data recorded in the MAC frame. According to the result of the mapping, the wireless signal processing unit 102 inputs the MAC frame to the corresponding transmission queue.

[0067] The wireless signal processing unit 102 confirms that no wireless signal is being transmitted by other terminals, etc., through carrier sensing for each access type, and waits for transmission for a time specified by the access parameters set for each access type. During the waiting period for transmission, if no other terminal, etc. is transmitting a wireless signal, the wireless signal processing unit 102 takes out a MAC frame from the corresponding transmission queue, converts the MAC frame into a wireless signal, and transmits it.

[0068] Here, access parameters can also be allocated so that the transmission of wireless signals is relatively prioritized in the order of VO, VI, BE, and BK. Access parameters can include CWmin, CWmax, AIFS, and TXOPLimit. CWmin and CWmax are the maximum and minimum values ​​of the waiting time for transmission, namely CW (Contention Window). The shorter CWmin and CWmax are, the easier it is for the sending queue to obtain the right to send. AIFS (Arbitration Inter Frame Space) is the transmission interval of the wireless signal. The smaller the AIFS, the higher the priority of the sending queue. TXOPLimit is the upper limit of the channel occupancy time, namely TXOP (Transmission Opportunity). The larger the value of TXOPLimit, the more wireless signals can be sent with one transmission right.

[0069] Figure 6 2 is a functional block diagram of the terminal 20. The terminal 20 includes a data processing unit 201, a wireless signal processing unit 202, and a measuring unit 203. The data processing unit 201, the wireless signal processing unit 202, and the measuring unit 203 are implemented by the processor 21 and the wireless module 24, for example.

[0070] The data processing unit 201 forms a MAC frame based on data input from, for example, an upper application. In addition, the data processing unit 201 restores data based on the MAC frame forwarded from the wireless signal processing unit 202. The data is used, for example, by an upper application. In addition, the data processing unit 201 generates a report including the measurement results of the measuring unit 203. In addition, the data processing unit 201 forms a MAC frame based on the report. Here, the application is not limited to a specific application. For example, the application may also be an RTA such as an online game or an industrial robot control application.

[0071] The wireless signal processing unit 202 performs processing for sending or receiving wireless signals. For example, the wireless signal processing unit 202 converts the MAC frame formed by the data processing unit 201 into a wireless signal, and transmits the wireless signal, for example, to the access point 10. In addition, the wireless signal processing unit 202 receives a wireless signal from the access point 10, extracts the MAC frame from the received wireless signal, and forwards it to the data processing unit 201. Here, the wireless signal processing unit 202 may also be configured to transmit a wireless signal using EDCA, similarly to the access point 10.

[0072] The measuring unit 203 measures at least one of the delay in the transmission of the wireless signal and the fluctuation of the wireless signal in the terminal 20. For example, the delay is measured based on the time from the wireless signal processing unit 202 implementing the transmission of the wireless signal to the time of receiving the confirmation (ACK) from the access point 10. In addition, the delay can be measured based on the queue waiting time from the MAC frame input to the end of the transmission queue until it reaches the front of the transmission queue. In addition, the delay can also be measured based on the transmission waiting time from the MAC frame coming to the front of the transmission queue until the transmission is implemented. In addition, the delay can also be measured based on the required retransmission time from the request for retransmission to the implementation of retransmission. Multiple delays among these can also be measured. For example, the fluctuation is measured based on the variance relative to the average value of the delay. The delay measurement method and the fluctuation measurement method are not limited to specific methods. In addition, the time information used for the measurement can be provided to each functional unit by a common clock (not shown) possessed by the terminal.

[0073] Fig. 7A This is a diagram showing the first example of the format of the MAC payload of the report. The payload of the report includes a data field of the measurement results of each access type. The measurement result is at least one of the measurement result of the delay and the measurement result of the fluctuation. The measurement result can be a measured value of the delay or fluctuation measured in each measurement, or a statistical value calculated by performing statistical processing on the measurement values ​​measured in multiple measurements. The statistical value includes, for example, values ​​such as the average value, the central value, the maximum value, and the minimum value. The payload of the report can store any one of these statistical values ​​for each access type, or can store multiple values ​​for each access type. Here, it is preferred that when calculating the statistical values ​​such as the average value, the central value, the maximum value, and the minimum value, outliers that deviate greatly from the results of other measurements are excluded from the results of multiple measurements. In addition, in the case of measuring both delay and fluctuation, when the fluctuation is large, outliers are likely to occur, for example, the number of measurement values ​​used for calculating the average value can be reduced.

[0074] For example, Fig. 7A The report shown can be sent using the Action frame in the IEEE802.11 standard. For example, when the access point requests each terminal to report, the request for the report can also be made by adding an Action frame to which a new field containing a status notification request for requesting the report is added. The terminal responds with the report by receiving the Action frame. When responding with the report, the terminal can use an Action frame to which a new field for storing the measurement result of the delay is added. In this case, Fig. 8A As shown, the terminal can perform the usual CSMA / CA procedure to reply to the report after receiving the request from the access point. Figure 8BAs shown in FIG. 1 , after receiving a request from an access point, the terminal may also reply to the report quickly, for example, after SIFS (Short Inter Frame Space: Short Inter Frame Space) or PIFS (PCF Inter Frame Space: Point Inter Frame Space) has passed without performing the CSMA / CA procedure. In addition, the access point may also periodically report a management frame or control frame for requesting a report, and each terminal may send a report. For example, the access point may also include a report request in a frame periodically sent by a beacon, etc. Fig.9A As shown in FIG. 1 , the terminal can also reply to the report request through an Action frame. Fig. 9B As shown, the terminal may also append a report to a data frame. For example, when the terminal sends data with a limited delay, by adding information such as the delay measured when sending the same type of data (access type, etc.) last time, the access point can be notified of the delay status in a relatively real-time manner. When appending a report to a data frame, for example, a new field storing information such as delay can be added to the header of the data frame.

[0075] In addition, Fig. 7A In the example, the measurement results are stored for each access type. However, the reported payload may not necessarily be stored for each access type. For example, the transmission control method of the wireless LAN also has a method that is not accompanied by priority control for each access type. In this case, it is not necessary to store the measurement results for each access type. In addition, the measurement results may be stored for each traffic type (TID) instead of the access type. The TID is assigned in units of applications (sessions) processed by the terminal 20. Mapping to the aforementioned access types can be performed based on the TID. By storing the measurement results for each TID, the delay and fluctuation differentiated for each application can be measured.

[0076] Figure 7B 1 is a diagram showing a second example of the format of the MAC payload of the report. The payload of the report includes attribute information of the measurement result in addition to the data field of the measurement result of each access type. The attribute information includes information related to the terminal, such as the location of the terminal 20 when the delay or fluctuation is measured, the type of the terminal 20, and the type of application executed by the terminal 20.

[0077] Next, the operation of the communication system 1 will be described. In the following description, the terminal 20 transmits a wireless signal and the access point 10 receives the wireless signal.

[0078] Fig.10 FIG. 2 is a flowchart showing an example of the transmission processing of the terminal 20. In step S31, the data processing unit 201 determines whether data to be transmitted from a higher layer such as an application layer is input. In step S31, when it is determined that no data is input, Fig.10 The processing is completed. In step S31, when it is determined that it is input data, the processing moves to step S32.

[0079] In step S32, the data processing unit 201 processes the input data. Figure 4 The data processing unit 201 outputs the MAC frame to the wireless signal processing unit 202 .

[0080] In step S33, the wireless signal processing unit 202 performs transmission processing using EDCA. That is, the wireless signal processing unit 202 inputs the MAC frame into the transmission queue according to the access type corresponding to the type of the data. In addition, the wireless signal processing unit 202 performs carrier sensing to determine the state of the channel, and waits for transmission according to the time specified by the access parameter of each access type. In addition, if other terminals are not using the channel, the MAC frame is converted into a wireless signal and the wireless signal is transmitted.

[0081] In step S34, the wireless signal processing unit 202 acquires the time at which the wireless signal is transmitted as the transmission start time. The wireless signal processing unit 202 outputs the transmission start time to the measurement unit 203 together with the sequence number assigned to the MAC frame and the access type to which the MAC frame is mapped.

[0082] In step S35, the wireless signal processing unit 202 determines whether an acknowledgment (ACK) is received from the access point 10. In step S35, the wireless signal processing unit 202 waits for processing until an ACK is received. In step S35, if it is determined that an ACK is received, the processing moves to step S36. Fig.10 Although not shown, the wireless signal processing unit 202 may retransmit the MAC frame when a retransmission request is received from the access point 10. The retransmission may be performed in units of MPDUs.

[0083] In step S36, the wireless signal processing unit 202 acquires the time of receiving ACK as the transmission completion time. The wireless signal processing unit 202 outputs the transmission completion time to the measurement unit 203 together with the sequence number assigned to the MAC frame and the access type to which the MAC frame is mapped.

[0084] In step S37, the measuring unit 203 calculates the delay and the fluctuation for each access type. For example, the delay is calculated based on the time difference between the transmission completion time and the transmission start time. On the other hand, the fluctuation can be calculated based on the variance relative to the average value of the delay, for example. The measuring unit 203 outputs the measurement result together with the access type and the sequence number to the data processing unit 201.

[0085] In step S38, the data processing unit 201 stores the measurement results of the delay and the fluctuation. Then, the process returns to step S31. The measurement results may be stored in the memory 26, for example.

[0086] Fig.11 2 is a flowchart showing the report processing in the terminal 20. For example, the report processing is performed at a fixed period such as every hour, every day, or every week. The fixed period can be set appropriately. In addition, when the measured value or statistical value exceeds the threshold value set as the request condition by the application, the report processing can be performed immediately in addition to the periodicity.

[0087] In step S41, the data processing unit 201 determines whether to generate a report. For example, when a measurement result sufficient to calculate a statistical value is obtained after a constant period has passed, or when a request is received from the access point 10, it is determined to generate a report. In step S41, if it is determined that a report is not generated, the process moves to step S45. In step S41, if it is determined that a report is generated, the process moves to step S42. In the case of receiving a request for report transmission from the access point through an Action frame, it can be determined to generate a report. When a delay is applied to the transmission of the previous data frame each time a data frame is transmitted, it can be set as a trigger for determining to generate a report on the transmission of a data frame.

[0088] In step S42 , the data processing unit 201 acquires the measurement results stored in, for example, the storage 26 for each access type.

[0089] In step S43, the data processing unit 201 generates Fig. 7A or Figure 7B The data processing unit 201 performs statistical processing such as calculating the average value of the acquired measurement results for each access type as necessary.

[0090] In step S44, the data processing unit 201 stores the report. The report may be stored in the storage 26, for example.

[0091] In step S45, the data processing unit 201 determines whether to send a report to the access point 10. For example, when a constant period has passed, when a measured value or a statistical value exceeds a threshold value as a request condition set by an application, or when there is a request from the access point 10, it is determined to send a report. In step S45, if it is determined that a report is to be sent, the process moves to step S46. In step S45, if it is determined that a report is not to be sent, Fig.11 The processing is finished.

[0092] In step S46, the data processing unit 201 acquires the report data from the storage 26, for example. Then, the data processing unit 201 processes the acquired data. Figure 4The data processing unit 201 generates a MAC frame by performing the processing of the MAC layer shown in FIG.

[0093] In step S47 , the wireless signal processing unit 202 performs transmission processing using EDCA.

[0094] In step S48, the wireless signal processing unit 202 determines whether an ACK is received from the access point 10. In step S48, the wireless signal processing unit 202 waits for processing until an ACK is received. In step S48, when it is determined that an ACK is received, Fig.11 The processing is finished.

[0095] Fig.12 FIG. 1 is a flowchart showing the receiving process of the access point 10. In step S51, the wireless signal processing unit 102 determines whether a wireless signal is received. In step S51, if it is determined that no wireless signal is received, Fig.12 The processing is completed. In step S51, when it is determined that a wireless signal is received, the processing moves to step S52.

[0096] In step S52, the wireless signal processing unit 102 performs reception processing. That is, the wireless signal processing unit 102 performs demodulation processing on the wireless signal and extracts the MAC frame. The wireless signal processing unit 102 outputs the MAC frame to the data processing unit 101. The data processing unit 101 performs MAC layer processing on the MAC frame to restore data.

[0097] In step S53, the data processing unit 101 determines whether the reception is successful. For example, the CRC can be used to determine whether the reception is successful. In step S53, if it is determined that the reception is successful, the process moves to step S54. In step S53, if it is determined that the reception is not successful, the process moves to step S55.

[0098] In step S54 , the data processing unit 101 causes the wireless signal processing unit 102 to transmit ACK.

[0099] In step S55, the data processing unit 101 causes the wireless signal processing unit 102 to request retransmission of the MAC frame. The retransmission request may be made in units of MPDUs.

[0100] In step S56, the data processing unit 101 outputs the data to a higher layer such as an application layer. Thereafter, the process returns to step S51.

[0101] Fig.13 2 is a flowchart showing the reporting process in the access point 10. The reporting process is performed at a fixed period such as every hour, every day, or every week. The fixed period can be set appropriately.

[0102] In step S61, the management unit 103 determines whether a report is requested. For example, when a constant period has passed and a report is required for delay control of RTA, it is determined that a report is requested. In step S61, when it is determined that a report is not requested, Fig.13 The processing ends. In step S61, when it is determined that a report is requested, the processing moves to step S62.

[0103] In step S62 , the management unit 103 causes the wireless signal processing unit 102 to request a report.

[0104] In step S63, the wireless signal processing unit 102 performs reception processing. That is, the wireless signal processing unit 102 performs demodulation processing on the wireless signal and extracts the MAC frame. The wireless signal processing unit 102 outputs the MAC frame to the data processing unit 101. The data processing unit 101 performs MAC layer processing on the MAC frame and restores the report data.

[0105] In step S64, the data processing unit 101 determines whether the reception is successful. In step S64, if it is determined that the reception is successful, the process moves to step S65. In step S64, if it is determined that the reception is unsuccessful, the process moves to step S66.

[0106] In step S65 , the data processing unit 101 causes the wireless signal processing unit 102 to transmit ACK. The data processing unit 101 outputs the report data to the management unit 103 .

[0107] In step S66, the data processing unit 101 causes the wireless signal processing unit 102 to request retransmission of the MAC frame. The request for retransmission may be made in units of MPDUs.

[0108] In step S67, the management unit 103 stores the report. Thereafter, the process returns to step S61. The measurement result may be stored in the ROM 12, for example.

[0109] As described above, according to the implementation method, the terminal measures at least one of the delay and fluctuation when sending a wireless signal. Moreover, the terminal sends a report containing data of the measurement results to the access point. Therefore, the access point can grasp the state of the wireless section between the corresponding terminal based on the measurement results recorded in the report. As a result, the access point can infer whether the request conditions of delay or fluctuation are met before actually inputting the RTA traffic, and take countermeasures as needed. For example, if the request conditions are not met, the access point makes a judgment not to process the RTA traffic, and can refuse when receiving a request for the exchange of RTA traffic. Alternatively, the access point can also adjust access parameters, etc. to meet the request conditions. In addition, the access point can also evaluate the reports of multiple terminals (calculate the average, dispersion variance, etc.) when making these judgments. In this way, in the implementation method, even in the case of absolute delay and fluctuation request conditions, information that is conducive to ensuring the request conditions can be provided to the access point.

[0110] [Modifications]

[0111] A variation of the implementation method is described below. In addition to the measurement results of the delay or fluctuation of each access type of the terminal, the report may also have information related to the interference status in the terminal. There is a situation where, even within the same service area of ​​the access point, depending on the location of the terminal, the transmission opportunity (TXOP) cannot be obtained due to the influence of other interference sources, and the delay becomes larger. In the case of such a terminal, the delay characteristics deviate. For example, by sending information related to such interference as a report to the access point, the access point can distinguish between terminals with larger interference and terminals with smaller interference, thereby expecting to improve the accuracy of the delay characteristics within the service area.

[0112] When the access point communicates with the terminal, Fig.14 As shown in FIG. 1 , the access point 10 periodically transmits a beacon. The terminal 20 calculates the reception success rate of the beacon from the access point 10 as information for evaluating interference in the terminal 20. In addition, the terminal 20 calculates the difference between the time (time stamp) stored in the beacon when the access point 10 creates the beacon and the time when the beacon is received as information for evaluating interference in the terminal 20. The terminal 20 includes the information for evaluating interference in a report and transmits it to the access point 10. In addition, the information for evaluating interference in the terminal 20 is not limited to specific information.

[0113] In addition, in the aforementioned embodiment and its variant, at least one of delay and fluctuation is measured at the terminal, and the measurement result is reported from the terminal to the access point. Conversely, at least one of delay and fluctuation is measured at the access point, and the measurement result is reported from the access point to the terminal. In this case, the access point performs Fig.10 as well as Fig.11Processing is performed at the terminal Fig.12 as well as Fig.13 In the case of an access point, the measurement result may be included in a beacon and sent to the terminal.

[0114] In addition, each process according to the above-mentioned embodiment can also be stored as a program to be executed by a processor as a computer. In addition, it can be stored in a storage medium of an external storage device such as a magnetic disk, an optical disk, a semiconductor memory, and distributed. And, the processor reads the program stored in the storage medium of the external storage device, and controls the action through the read program, so that the above-mentioned process can be executed.

[0115] Description of Reference Numerals

[0116] 1…Communication system

[0117] 10…Access Point

[0118] 11…Processor

[0119] 12…ROM

[0120] 13…RAM

[0121] 14…Wireless module

[0122] 15…Router module

[0123] 20…Terminal

[0124] 21…Processor

[0125] 22…ROM

[0126] 23…RAM

[0127] 24…Wireless module

[0128] 25…Display

[0129] 26… Storage

[0130] 101…Data Processing Department

[0131] 102…Wireless signal processing unit

[0132] 103…Administration Department

[0133] 201…Data Processing Department

[0134] 202…Wireless Signal Processing Department

[0135] 203…Measurement Department.

Claims

1. A terminal comprising: a measuring unit configured to measure at least one of a delay in sending a wireless signal to an access point and a fluctuation of the wireless signal; a data processing unit that generates information including the measurement result; and The wireless signal processing unit sends the information to the access point. The measuring unit measures at least one of the delay and the fluctuation for each flow identification information assigned to data included in the wireless signal.

2. The terminal according to claim 1, wherein: The information includes information on attributes of the terminal.

3. A communication method, comprising: measuring, in the terminal, at least one of a delay in sending a wireless signal to an access point and a fluctuation of the wireless signal; The terminal generates information including a result of the measurement in the terminal; and The terminal sends the information to the access point, The measuring includes measuring at least one of the delay and the fluctuation according to each flow identification information assigned to the data included in the wireless signal.

4. A recording medium, which can be read by a processor having a communication program recorded thereon, wherein the communication program is used to cause the processor of a terminal to execute: measuring, in the terminal, at least one of a delay in sending a wireless signal to an access point and a fluctuation of the wireless signal; The terminal generates information including a result of the measurement in the terminal; and The terminal sends the information to the access point, The measuring includes measuring at least one of the delay and the fluctuation according to each flow identification information assigned to the data included in the wireless signal.

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