Transmitting station and receiving station

Abstract

This transmission station which is a station to transmit wireless signals, comprises a first wireless signal processing unit, a second wireless signal processing unit, and a transmission timing adjustment unit. The first wireless signal processing unit transmits and receives a wireless signal using a first channel. The second wireless signal processing unit transmits and receives a wireless signal using a second channel that is different from the first channel. The transmission timing adjustment unit adjusts the transmission timing of first and second data on the basis of a first status associated with the first wireless signal processing unit and a second status associated with the wireless signal processing unit.

Description

Technical Field

[0001] Embodiments relate to a transmitting station and a receiving station.

Background Art

[0002] A wireless LAN (Local Area Network) is known as a wireless system between a transmitting station that transmits a wireless signal and a receiving station that receives a wireless signal, such as a base station and a terminal.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Embodiments provide a transmitting station and a receiving station that can improve data transmission when there is mutual power leakage between a plurality of links when they attempt to transmit data simultaneously.

Means for Solving the Problems

[0005] In an embodiment, a transmitting station, which is a station that transmits a wireless signal, includes a first wireless signal processing unit, a second wireless signal processing unit, and a transmission timing adjustment unit. The first wireless signal processing unit transmits and receives a wireless signal using a first channel. The second wireless signal processing unit transmits and receives a wireless signal using a second channel different from the first channel. The transmission timing adjustment unit adjusts the transmission timing of first data and second data based on a first status related to the first wireless signal processing unit and a second status related to the second wireless signal processing unit.

Effects of the Invention

[0006] According to an embodiment, when a plurality of links transmit data simultaneously, a transmitting station and a receiving station that can improve the transmission of data in the case of power leakage between the links can be provided.

Brief Description of the Drawings

[0007]

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Mode for Carrying Out the Invention

[0008] Hereinafter, the embodiment will be described with reference to the drawings. FIG. 1 shows an example of the configuration of a radio system 1 according to the embodiment. As shown in FIG. 1, the radio system 1 includes, for example, a base station 10, a terminal 20, and a server 30.

[0009] The base station 10 is connected to the network NW and is used as an access point for a wireless LAN. For example, the base station 10 can wirelessly transmit data received from the network NW to the terminal 20. In addition, the base station 10 can be connected to the terminal 20 using one channel or a plurality of different channels. In this specification, the wireless connection using a plurality of different channels between the base station 10 and the terminal 20 is referred to as "multi-link". The communication between the base station 10 and the terminal 20 is based on, for example, the IEEE802.11 standard.

[0010] The terminal 20 is a wireless terminal such as a smartphone or a tablet PC. The terminal 20 can transmit and receive data to and from the server 30 on the network NW via the wirelessly connected base station 10. The terminal 20 may be other electronic devices such as a desktop computer or a laptop computer. The terminal 20 only needs to be able to communicate with at least the base station 10.

[0011] The server 30 can hold various information, for example, it holds content data targeted at the terminal 20. The server 30 is, for example, wired-connected to the network NW and configured to be able to communicate with the base station 10 via the network NW. The server 30 only needs to be able to communicate with at least the base station 10. That is, the communication between the base station 10 and the server 30 may be wired or wireless.

[0012] In the wireless system 1 according to the embodiment, the wireless communication between the base station 10 and the terminal 20 conforms to the IEEE802.11 standard. The IEEE802.11 standard defines the first layer and the MAC sublayer of the second layer of the OSI (Open Systems Interconnection) reference model. In the OSI reference model, the communication function is divided into seven layers (the first layer: physical layer, the second layer: data link layer, the third layer: network layer, the fourth layer: transport layer, the fifth layer: session layer, the sixth layer: presentation layer, the seventh layer: application layer). Also, the data link layer includes, for example, an LLC (Logical Link Control) layer and a MAC (Media Access Control) layer. In the LLC layer, for example, an LLC packet is formed by adding a DSAP (Destination Service Access Point) header, an SSAP (Source Service Access Point) header, etc. to the data input from the upper application. In the MAC layer, for example, a MAC frame is formed by adding a MAC header to the LLC packet. In this explanation, the processing related to the first layer and the MAC sublayer of the second layer defined by the IEEE802.11 standard is mainly explained, and the explanation of the processing of other layers is omitted.

[0013] Figure 2 shows a specific example of the format of the MAC frame used in the communication between the base station 10 and the terminal 20 in the wireless system 1 according to the embodiment. As shown in Figure 2, fields included in the MAC frame include, for example, Frame Control field, Duration field, Address1 field, Address2 field, Address3 field, Sequence Control field, Address4 field, QoS Control field, HT Control field, Frame Body field, and FCS (Frame Check Sequence) field. Some of these fields are included and some are not depending on the type of the wireless frame.

[0014] The fields from the Frame Control field to the HT Control field correspond to the MAC header. The Frame Body field corresponds to the MAC payload. The FCS field stores the error detection code for the MAC header and the Frame Body field. The FCS field is used to determine the presence or absence of errors in the MAC frame.

[0015] The Frame Control field contains various control information, such as Type value, Subtype value, To DS (Distribution System) value, From DS value, and Retry value.

[0016] The Type value indicates whether the MAC frame is a management frame, a control frame, or a data frame. The Subtype value, when used in combination with the Type value, indicates the frame type of the MAC frame. For example, "00 / 1000 (Type value / Subtype value)" indicates that the MAC frame is a beacon signal. Also, "00 / 0100 (Type value / Subtype value)" indicates that the MAC frame is a probe request. Also, "00 / 0101 (Type value / Subtype value)" indicates that the MAC frame is a probe response.

[0017] The To DS value and the From DS value have different meanings depending on their combination. For example, when the MAC frame is a data frame, a To DS value of "0" indicates that the receiving station is a terminal, and "1" indicates that the receiving station is a base station. Also, when the MAC frame is a data frame, a From DS value of "0" indicates that the transmitting station is a terminal, and "1" indicates that the transmitting station is a base station. On the other hand, when the MAC frame is a management frame or a control frame, the To DS value and the From DS value are fixed to, for example, "0".

[0018] The Retry value indicates whether the MAC frame is a retransmission frame. For example, a Retry value of "0" indicates that the MAC frame is not a retransmission frame, that is, it is the original MAC frame. On the other hand, a Retry value of "1" indicates that the MAC frame is a retransmission frame.

[0019] The Duration field indicates the scheduled period of using the wireless link. The Address field indicates the BSSID, source MAC address, destination MAC address, address of the sender terminal, address of the receiver terminal, etc. The number of Address fields used varies depending on the frame type. The Sequence Control field indicates the sequence number of the MAC frame and the fragment number for fragmentation. The QoS Control field is used for the QoS (Quality of Service) function in the MAC frame. The QoS Control field may include a Traffic Identifier (TID) subfield. The HT Control field is a Control field for the high throughput function. The Frame Body field contains information according to the frame type. For example, when the frame type is a data frame, the transmission data is stored in the Frame Body field.

[0020] Figure 3 shows an example of the configuration of base station 10. As shown in Figure 3, base station 10 includes, for example, a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a wireless communication module 14, and a wired communication module 15.

[0021] The CPU 11 is a circuit capable of executing various programs and controls the overall operation of base station 10. The ROM 12 is a non-volatile semiconductor memory and holds programs and control data for controlling base station 10. The RAM 13 is, for example, a volatile semiconductor memory and is used as the working area of the CPU 11. The wireless communication module 14 is a circuit used for transmitting and receiving data by wireless signals and is connected to an antenna. Also, the wireless communication module 14 includes, for example, a plurality of communication modules each corresponding to a plurality of frequency bands. The wired communication module 15 is a circuit used for transmitting and receiving data by wired signals and is connected to the network NW.

[0022] Figure 4 shows an example of the functional configuration of the base station 10. As shown in Figure 4, the base station 10 includes, for example, a data processing unit 100, a MAC frame processing unit 110, a management unit 120, and radio signal processing units 130, 140, 150, and a transmission timing adjustment unit 160. The processing of the data processing unit 100, the MAC frame processing unit 110, the management unit 120, the radio signal processing units 130, 140, 150, and the transmission timing adjustment unit 160 is realized, for example, by the CPU 11 and the wireless communication module 14.

[0023] The data processing unit 100 can execute LLC layer processing and upper layer (layer 3 to layer 7) processing on the input data. For example, the data processing unit 100 outputs the data input from the server 30 via the network NW to the MAC frame processing unit 110. Also, the data processing unit 100 transmits the data input from the MAC frame processing unit 110 to the server 30 via the network NW.

[0024] The MAC frame processing unit 110 executes, for example, MAC layer processing on the input data. For example, the MAC frame processing unit 110 generates a MAC frame from the data input from the data processing unit 100. Also, the MAC frame processing unit 110 restores data from the MAC frames input from the radio signal processing units 130, 140, 150, respectively. The process of generating a MAC frame from data and the process of restoring data from a MAC frame may be based on the IEEE802.11 standard.

[0025] The management unit 120 manages the link with the terminal 20 based on the notifications received from the wireless signal processing units 130, 140, 150 via the MAC frame processing unit 110. The management unit 120 includes link management information 121. The link management information 121 is stored in, for example, the RAM 13 and includes information on the terminal 20 wirelessly connected to the base station 10. Further, the management unit 120 includes an association processing unit 122 and an authentication processing unit 123. When the association processing unit 122 receives a connection request from the terminal 20 via any of the wireless signal processing units 130, 140, 150, it executes a protocol related to association. The authentication processing unit 123 executes a protocol related to authentication following the connection request. Hereinafter, the combination of the data processing unit 100, the MAC frame processing unit 110, and the management unit 120 is referred to as the link management unit LM1 of the base station 10.

[0026] Each of the wireless signal processing units 130, 140, 150 transmits and receives data between the base station 10 and the terminal 20 using wireless communication. For example, each of the wireless signal processing units 130, 140, 150 adds a preamble, a PHY header, etc. to the MAC frame input from the MAC frame processing unit 110 to create a wireless frame. Then, each of the wireless signal processing units 130, 140, 150 converts the wireless frame into a wireless signal and distributes the wireless signal via the antenna of the base station 10. Also, each of the wireless signal processing units 130, 140, 150 converts the wireless signal received via the antenna of the base station 10 into a wireless frame. Then, each of the wireless signal processing units 130, 140, 150 outputs the data (e.g., MAC frame) included in the wireless frame to the MAC frame processing unit 110.

[0027] In this way, each of the radio signal processing units 130, 140, and 150 can execute, for example, a part of the MAC layer processing and the first layer processing on the input data or radio signal. For example, the radio signal processing units 130, 140, and 150 handle radio signals in the 5 GHz band. The radio signal processing units 130, 140, and 150 may or may not share the antennas of the base station 10.

[0028] The transmission timing adjustment unit 160 adjusts the timing at which data is transmitted from each of the radio signal processing units 130, 140, and 150. The transmission timing adjustment unit 160 is notified of the carrier sense situation based on the carrier sense (CS) executed by each of the radio signal processing units 130, 140, and 150 from each of the radio signal processing units 130, 140, and 150. The transmission timing adjustment unit 160 manages the carrier sense situation notified from each of the radio signal processing units 130, 140, and 150 as status management information. Carrier sense is a process of detecting the usage state of a channel, and as a channel status, it determines whether the channel is in an unused state (idle state) or a used state (busy state). Carrier sense may be performed, for example, using CCA (Clear Channel Assessment). Each of the radio signal processing units 130, 140, and 150 notifies the transmission timing adjustment unit 160 of the scheduled time to acquire the transmission right when the idle state continues due to carrier sense, and the carrier sense situation. The carrier sense situation corresponds to the status of the channel access procedure. For example, it includes the start of the channel access procedure, the acquisition of the transmission right due to the completion of the channel access procedure, the cancellation of the channel access procedure when a busy state is detected, and the like. Each of the radio signal processing units 130, 140, and 150 notifies the transmission timing adjustment unit 160 of the carrier sense situation based on the change in the carrier sense situation.

[0029] The transmission timing adjustment unit 160 notifies the respective transmission control information of the wireless signal processing units 130, 140, and 150 based on the carrier sense status of each wireless signal processing unit. The transmission control information is information that indicates whether the notified wireless signal processing unit transmits data or not. The transmission control information is, for example, a transmission instruction that instructs the transmission of data, or a transmission standby instruction that instructs the standby for data transmission. Each of the wireless signal processing units 130, 140, and 150 transmits data when notified of the transmission instruction, and waits for data transmission when notified of the transmission standby instruction. Details of the operation of the transmission timing adjustment unit 160 will be described later with reference to FIG. 9.

[0030] FIG. 5 shows an example of the configuration of the terminal 20. As shown in FIG. 5, the terminal 20 includes, for example, a CPU 21, a ROM 22, a RAM 23, a wireless communication module 24, a display 25, and a storage 26.

[0031] The CPU 21 is a circuit capable of executing various programs and controls the overall operation of the terminal 20. The ROM 22 is a non-volatile semiconductor memory and holds programs, control data, etc. for controlling the terminal 20. The RAM 23 is, for example, a volatile semiconductor memory and is used as a working area for the CPU 21. The wireless communication module 24 is a circuit used for transmitting and receiving data by wireless signals and is connected to an antenna. Also, the wireless communication module 24 includes, for example, a plurality of communication modules corresponding to a plurality of frequency bands respectively. The display 25 displays, for example, a GUI (Graphical User Interface) corresponding to application software. The display 25 may have a function as an input interface of the terminal 20. The storage 26 is a non-volatile storage device and holds, for example, the system software of the terminal 20. The terminal 20 may not include a display.

[0032] FIG. 6 shows an example of the functional configuration of the terminal 20 included in the wireless system 1 according to the embodiment. As shown in FIG. 6, the terminal 20 includes, for example, a data processing unit 200, a MAC frame processing unit 210, a management unit 220, wireless signal processing units 230, 240, 250, a transmission timing adjustment unit 260, and an application execution unit 270. The processing of the data processing unit 200, the MAC frame processing unit 210, the management unit 220, the wireless signal processing units 230, 240, 250, and the transmission timing adjustment unit 260 is realized by, for example, the CPU 21 and the wireless communication module 24. The processing of the application execution unit 270 is realized by, for example, the CPU 21.

[0033] The data processing unit 200 can execute LLC layer processing and upper layer (layer 3 to layer 7) processing on the input data. For example, the data processing unit 200 outputs the data input from the application execution unit 270 to the MAC frame processing unit 210. Further, the data processing unit 200 outputs the data input from the MAC frame processing unit 210 to the application execution unit 270.

[0034] The MAC frame processing unit 210 executes, for example, MAC layer processing on the input data. The MAC frame processing unit 210 generates a MAC frame from the data input from the data processing unit 200. Further, the MAC frame processing unit 210 restores data from the MAC frames input from the wireless signal processing units 230, 240, 250, respectively. The process of generating a MAC frame from data and the process of restoring data from a MAC frame may be based on the IEEE802.11 standard.

[0035] The management unit 220 manages the link with the base station 10 based on the notifications received from the radio signal processing units 230, 240, 250 via the MAC frame processing unit 210. The management unit 220 includes link management information 221. The link management information 221 is stored in, for example, the RAM 23 and includes information on the base station 10 wirelessly connected to the terminal 20. The management unit 220 also includes an association processing unit 222 and an authentication processing unit 223. When the association processing unit 222 receives a connection request from the base station 10 via any of the radio signal processing units 230, 240, 250, it executes a protocol related to association. The authentication processing unit 223 executes a protocol related to authentication following the connection request. Hereinafter, the combination of the data processing unit 200, the MAC frame processing unit 210, and the management unit 220 is referred to as the link management unit LM2 of the terminal 20.

[0036] Each of the radio signal processing units 230, 240, 250 transmits and receives data between the base station 10 and the terminal 20 using wireless communication. For example, each of the radio signal processing units 230, 240, 250 adds a preamble, a PHY header, etc. to the MAC frame input from the MAC frame processing unit 210 to create a wireless frame. Then, each of the radio signal processing units 230, 240, 250 converts the wireless frame into a wireless signal and distributes the wireless signal via the antenna of the terminal 20. Also, each of the radio signal processing units 230, 240, 250 converts the wireless signal received via the antenna of the terminal 20 into a wireless frame. Then, each of the radio signal processing units 230, 240, 250 outputs the data (e.g., MAC frame) included in the wireless frame to the MAC frame processing unit 210.

[0037] Thus, each of the radio signal processing units 230, 240, 250 can execute, for example, a part of the MAC layer processing and the first layer processing on the input data or wireless signal. For example, the radio signal processing units 230, 240, 250 handle wireless signals in the 5 GHz band. The radio signal processing units 230, 240, 250 may or may not share the antenna of the terminal 20.

[0038] The transmission timing adjustment unit 260 adjusts the timing at which data is transmitted from each of the wireless signal processing units 230, 240, and 250. The function of the transmission timing adjustment unit 260 is the same as that of the transmission timing adjustment unit 160 described above. That is, the transmission timing adjustment unit 260 manages the carrier sense status notified from each of the wireless signal processing units 230, 240, and 250. Further, the transmission timing adjustment unit 260 notifies each wireless signal processing unit of the transmission control information of each of the wireless signal processing units 230, 240, and 250 based on the carrier sense status of each wireless signal processing unit.

[0039] The application execution unit 270 executes an application that can utilize the data input from the data processing unit 200. For example, the application execution unit 270 can display application information on the display 25. Further, the application execution unit 270 can operate based on an operation of the input interface.

[0040] In the wireless system 1 according to the embodiment described above, the wireless signal processing units 130, 140, and 150 of the base station 10 are configured to be connectable to the wireless signal processing units 230, 240, and 250 of the terminal 20, respectively. That is, each of between the wireless signal processing units 130 and 230, between the wireless signal processing units 140 and 240, and between the wireless signal processing units 150 and 250 can be wirelessly connected using the 5 GHz band. In this specification, each wireless signal processing unit may be called a "STA function". That is, the wireless system 1 according to the embodiment includes a plurality of STA functions.

[0041] Figure 7 shows the details of the channel access function in the radio signal processing unit of the base station 10. In the example of the embodiment, the radio signal processing units 130, 140, and 150 each have a channel access function. In Figure 7, the channel access function of the radio signal processing unit 130 is shown. The channel access functions of the radio signal processing units 140 and 150 are the same as the channel access function in the radio signal processing unit 130. Therefore, the description of the channel access functions of the radio signal processing units 140 and 150 is omitted. Also, the radio signal processing units 230, 240, and 250 of the terminal 20 each have a channel access function. The channel access functions of the radio signal processing units 230, 240, and 250 are also the same as the channel access function in the radio signal processing unit 130. Therefore, the description of the channel access functions of the radio signal processing units 230, 240, and 250 is omitted.

[0042] As shown in Figure 7, the channel access function includes, for example, a data categorization unit 131, transmission queues 132A, 132B, 132C, and 132D, CSMA / CA execution units 133A, 133B, 133C, and 133D, and a data collision management unit 134. In the embodiment, for example, the channel access function is realized using EDCA (Enhanced Distribution Channel Access).

[0043] The data categorization unit 131 categorizes the data of the MAC frame input from the MAC frame processing unit 110 using, for example, a TID. The TID is assigned in units of applications (sessions) handled by the terminal 20 and represents the type of traffic. As data categories, for example, "VO (Voice)", "VI (Video)", "BE (Best Effort)", and "BK (Background)" are set.

[0044] Then, the data categorization unit 131 inputs the MAC frame including the categorized data into any one of the transmission queues 132A, 132B, 132C, and 132D. Specifically, the MAC frame including the VO data is input into the transmission queue 132A. The MAC frame including the VI data is input into the transmission queue 132B. The MAC frame including the BE data is input into the transmission queue 132C. The MAC frame including the BK data is input into the transmission queue 132D. Then, each of the input MAC frames is stored in any one of the corresponding transmission queues 132A to 132D.

[0045] When data is input into any one of the transmission queues 132A to 132D, each of the CSMA / CA execution units 133A, 133B, 133C, and 133D executes the channel access procedure and notifies the transmission timing adjustment unit 160 of the start of the channel access procedure as the carrier sense status. Also, together with this notification, the CSMA / CA execution units 133A, 133B, 133C, and 133D notify the transmission timing adjustment unit 160 of the scheduled completion time of the channel access procedure. Each of the CSMA / CA execution units 133A, 133B, 133C, and 133D waits for transmission for a time defined by the preset access parameters while confirming by carrier sense that there is no transmission of a wireless signal by other terminals or the like in CSMA / CA.

[0046] When the channel access procedure is completed, each of the CSMA / CA execution units 133A, 133B, 133C, and 133D notifies the transmission timing adjustment unit 160 of the completion of the channel access procedure as the carrier sense status. After notifying the transmission timing adjustment unit 160 of the carrier sense status, each of the CSMA / CA execution units 133A, 133B, 133C, and 133D waits for a notification of transmission control information from the transmission timing adjustment unit 160. If the channel status becomes busy while waiting for transmission for the aforementioned specified time, each of the CSMA / CA execution units 133A, 133B, 133C, and 133D aborts the channel access procedure and notifies the transmission timing adjustment unit 160 of the abort of the channel access procedure as the carrier sense status.

[0047] When the CSMA / CA execution units 133A, 133B, 133C, and 133D can obtain the transmission right, they extract the MAC frame from the corresponding transmission queues 132A, 132B, 132C, and 132D, and output the extracted MAC frame to the STA function via the data collision management unit 134. Then, the STA function of the radio signal processing unit 130 generates a radio signal based on the input MAC frame. The radio signal processing unit 130 transmits the radio signal based on the transmission control information notified by the transmission timing adjustment unit 160.

[0048] The CSMA / CA execution unit 133A executes CSMA / CA for the MAC frame including the VO data held in the transmission queue 132A. The CSMA / CA execution unit 133B executes CSMA / CA for the MAC frame including the VI data held in the transmission queue 132B. The CSMA / CA execution unit 133C executes CSMA / CA for the MAC frame including the BE data held in the transmission queue 132C. The CSMA / CA execution unit 133D executes CSMA / CA for the MAC frame including the BK data held in the transmission queue 132D.

[0049] In EDCA, access parameters are assigned such that wireless signal transmissions are prioritized in the order of, for example, VO, VI, BE, and BK. The access parameters include, for example, CWmin, CWmax, AIFS, and TXOPLimit. CWmin and CWmax respectively indicate the minimum and maximum values of the contention window CW (Contention Window), which is the transmission waiting time for collision avoidance. AIFS (Arbitration Inter Frame Space) indicates the fixed transmission waiting time set for each access category for collision avoidance control with a priority control function. TXOPLimit indicates the upper limit value of TXOP (Transmission Opportunity) corresponding to the channel occupancy time. For example, the shorter CWmin and CWmax are, the easier it is for the transmission queue to obtain the right to transmit. The priority of the transmission queue increases as AIFS decreases. The amount of data transmitted with one transmission right increases as the value of TXOPLimit increases.

[0050] The data collision management unit 134 prevents data collisions when multiple CSMA / CA execution units acquire the right to transmit with the same STA function. Specifically, the data collision management unit 134 adjusts the transmission timing of data for which the right to transmit has been acquired with the same STA function but different categories. The data collision management unit 134 transmits from the MAC frame including data of the category with higher priority to the STA function. For example, there may be a case where an STA function that has acquired the right to transmit by CSMA / CA of the VO transmission queue 132A acquires the right to transmit at the same time as an STA function that has acquired the right to transmit by CSMA / CA of any of the other transmission queues 132B to 132D. In this case, the data collision management unit 134 preferentially transmits the MAC frame stored in the transmission queue 132A to the STA function. Similarly, in combinations of the other transmission queues 132B to 132D, the MAC frames are transmitted in the order based on the priority set for the category. This prevents collisions between data assigned for transmission to the same STA function.

[0051] Next, an example of the operation related to the multi-link of the wireless system 1 according to the embodiment will be described. In the following description, for the sake of simplicity, it is assumed that the base station 10 and the terminal 20 establish a multi-link with two STA functions STA1 and STA2, respectively.

[0052] FIG. 8 is a flowchart showing an example of multi-link processing in the wireless system 1 according to the embodiment. As shown in FIG. 8, in the multi-link processing, for example, the processes of steps S10 to S16 are executed in order.

[0053] Specifically, first, in the process of step S10, the terminal 20 transmits a probe request to the base station 10. The probe request is a signal for checking whether the base station 10 exists around the terminal 20. The Frame Control field of the probe request includes, for example, "00 / 0100 (Type value / Subtype value)". When the base station 10 receives the probe request, it executes the process of step S11.

[0054] In the process of step S11, the base station 10 transmits a probe response to the terminal 20. The probe response is a signal used by the base station 10 for the response to the probe request from the terminal 20. The Frame Control field of the probe response includes, for example, "00 / 0101 (Type value / Subtype value)". When the terminal 20 receives the probe response, it executes the process of step S12.

[0055] In the process of step S12, the terminal 20 transmits a multi-link association request to the base station 10 via at least one STA function. The multi-link association request is a signal for requesting the establishment of a multi-link with the base station 10. For example, the multi-link association request is generated by the management unit 220 of the terminal 20. The Frame Control field of the multi-link association request contains, for example, "00 / 0000 (Type value / Subtype value)". When the management unit 120 of the base station 10 receives the multi-link association request, it executes the process of step S13.

[0056] In the process of step S13, the management unit 120 of the base station 10 executes multi-link association processing using one STA function. Specifically, first, the base station 10 executes the association process of the first STA function with the terminal 20. Then, when a wireless connection (link) is established in the first STA function, the management unit 120 of the base station 10 executes the association process of the second STA function using the first STA function in which the link is established. That is, the STA function in which the link is established is used for the association process of the STA function in which the link is not established. When the association processes of at least two STA functions are completed, the base station 10 establishes a multi-link and executes the process of step S14.

[0057] When a link is established in the first STA function, a multi-link may be established. For example, when each of the base station 10 and the terminal 20 notifies the multi-link capability, the link to be the multi-link, the operation parameters in each link, etc. prior to the association process, the association for the multi-link can be executed collectively. Specifically, when the first STA function starts the association, the management units 120 and 220 instruct the establishment of the multi-link and specify the link to be the multi-link, etc. Then, the management units 120 and 220 execute the association of the links respectively and manage these links as a multi-link.

[0058] In the process of step S14, the management unit 120 of the base station 10 updates the link management information 121. In this example, the process of step S14 is executed after two links are established. However, the link management information 121 may be updated each time the link state is updated, or may be updated when the multi-link is established. When the multi-link is established and the link management information is updated, the base station 10 executes the process of step S15.

[0059] In the process of step S15, the base station 10 transmits a multi-link establishment response to the terminal 20. The multi-link establishment response is a signal used by the base station 10 for the response to the multi-link request from the terminal 20. The Frame Control field of the multi-link establishment response includes, for example, "00 / 0001 (Type value / Subtype value)". Based on receiving the multi-link establishment response, the management unit 220 of the terminal 20 recognizes that the multi-link with the base station 10 is established. When the terminal 20 receives the multi-link establishment response, it executes the process of step S16.

[0060] In the process of step S16, the management unit 220 of the terminal 20 updates the link management information 221. That is, the terminal 20 records in the link management information 221 that the multi-link with the base station 10 has been established. Thereby, the setup of the multi-link in the wireless system 1 according to the embodiment is completed, and wireless communication using the multi-link becomes possible between the base station 10 and the terminal 20.

[0061] FIG. 9 is a table showing an example of the wireless signal transmission process in the wireless system according to the embodiment. Hereinafter, it is assumed that the base station 10 is a transmission station that transmits a wireless signal. In FIG. 9, the processing condition is a condition that triggers the transmission timing adjustment unit 160 to execute a predetermined process. The processing of the situation management information is the content of the process that the transmission timing adjustment unit 160 executes on the situation management information of each wireless signal processing unit. The situation of other wireless signal processing units is the situation management information of wireless signal processing units other than the wireless signal processing unit that has notified the transmission timing adjustment unit 160 of the carrier sense situation. The processing content is the content of the predetermined process executed by the transmission timing adjustment unit 160. The processing target is the target on which the transmission timing adjustment unit 160 executes a predetermined process. That is, based on the satisfaction of the processing condition, the transmission timing adjustment unit 160 executes the processing content on the processing target.

[0062] In this embodiment, any one of the wireless signal processing units 130, 140, and 150 notifies the transmission timing adjustment unit 160 of the carrier sense (CS) situation. When the completion of the channel access (CA) procedure is notified to the transmission timing adjustment unit 160 as the carrier sense situation, the transmission timing adjustment unit 160 updates the status management information of the wireless signal processing unit that notified the carrier sense situation to the content indicating the completion of the channel access procedure. The transmission timing adjustment unit 160 checks the status management information of the wireless signal processing units other than the wireless signal processing unit that notified the carrier sense situation (other wireless signal processing units). At this time, if the status management information of all other wireless signal processing units indicates the completion of the CA procedure, the transmission timing adjustment unit 160 notifies all other wireless signal processing units of a transmission instruction as transmission control information. When the status management information of at least one other wireless signal processing unit indicates that the CA procedure is in progress, the transmission timing adjustment unit 160 notifies the wireless signal processing unit that updated the status management information of a transmission standby instruction as transmission control information.

[0063] When the start of the channel access procedure is notified to the transmission timing adjustment unit 160 as the carrier sense situation, the transmission timing adjustment unit 160 updates the status management information of the wireless signal processing unit that notified the carrier sense situation to the content indicating that the channel access procedure is in progress. At this time, the transmission timing adjustment unit 160 does not execute processing related to the status management information of other wireless signal processing units. For example, the transmission timing adjustment unit 160 does not execute any special processing on other wireless signal processing units.

[0064] When the transmission timing adjustment unit 160 is notified of the cancellation of the channel access procedure as the carrier sense status, the transmission timing adjustment unit 160 clears the status management information of the radio signal processing unit that notified the carrier sense status. At this time, if the status management information of all other radio signal processing units indicates the completion of the CA procedure, the transmission timing adjustment unit 160 notifies all other radio signal processing units of a transmission instruction as transmission control information. When the status management information of at least one other radio signal processing unit indicates that the CA procedure is in progress, the transmission timing adjustment unit 160 does not execute processing related to the status management information of the other radio signal processing units.

[0065] As described above, the transmission timing adjustment unit 160 adjusts the data transmission timing of the radio signal processing units 130, 140, and 150 by notifying each of the radio signal processing units of transmission control information based on a predetermined condition. Even when the data transmission timing of the radio signal processing units 130, 140, and 150 is appropriately adjusted in this way, the time required to transmit data from each of the radio signal processing units 130, 140, and 150 may be different. In this case, for example, if there is power leakage between a plurality of links, an ACK may not be received on the link corresponding to the radio signal processing unit 140 while data is being transmitted on the link corresponding to the radio signal processing unit 130. As described below, in the present embodiment, the transmission timing adjustment unit 160 executes a process of adjusting the ACK reply timing from the receiving station, so that the ACK reply timing from the receiving station to the transmitting station is appropriately adjusted.

[0066] The transmission timing adjustment unit 160, as an adjustment process for the ACK reply timing from the receiving station, notifies each of the radio signal processing units 130, 140, and 150 of the ACK reply timing common to the radio signal processing units 130, 140, and 150 based on the maximum value of the time required for transmitting the respective data of the radio signal processing units 130, 140, and 150. That is, the reply timing is equal to or greater than the maximum value of the time required for data transmission by the radio signal processing units 130, 140, and 150. Each of the radio signal processing units 130, 140, and 150 stores the above-mentioned ACK reply timing in the MAC header, for example, and transmits the data to the receiving station. The radio signal processing unit of the receiving station transmits an ACK to the transmitting station according to the ACK reply timing of the received MAC header. When the ACK reply timing is adjusted as described above, if the adjusted reply timing exceeds the ACK reception deadline, the radio signal processing unit of the transmitting station can extend the ACK reception deadline. For example, the radio signal processing unit of the transmitting station sets the ACK reception deadline in consideration of a period corresponding to the maximum value of the time required for data transmission.

[0067] In an example shown in FIG. 10, the data transmission time T1 of the STA function STA1 is shorter than the data transmission time T2 of the STA function STA2. In this case, the transmission timing adjustment unit 160 sets, as the ACK reply timing TR common to the STA function STA1 and the STA function STA2, a value that elapses T2 or more from the start of data transmission. Then, the transmission timing adjustment unit 160 notifies the STA functions STA1 and STA2 of the ACK reply timing TR. In the STA functions STA1 and STA2, the transmitting station stores the ACK reply timing TR in the MAC header and transmits it to the receiving station, and the receiving station transmits an ACK to the transmitting station when the ACK reply timing TR is reached.

[0068] The transmission timing adjustment unit 160 notifies, as adjustment processing different from the aforementioned ACK reply timing from the receiving station, the timing for transmitting a BAR (Block ACK Request) from each of the radio signal processing units 130, 140, and 150. The BAR is used for the transmitting station to request a confirmation response for the frames normally received by the receiving station. Each of the radio signal processing units 130, 140, and 150 transmits the BAR to the receiving station according to the transmission timing of the BAR notified by the transmission timing adjustment unit 160. After receiving the BAR, the receiving station transmits a response to the transmitting station by block ACK. At this time, the BAR is created by each of the radio signal processing units 130, 140, and 150.

[0069] In an example shown in FIG. 11, the transmission timing adjustment unit 160 notifies the transmission timing TB of the BAR to the STA functions STA1 and STA2 of the transmitting station. The transmission timing TB is at least the timing after at least the STA functions STA1 and STA2 have completed data transmission. In the STA functions STA1 and STA2, when the transmission timing TB is reached at the transmitting station, the BAR is transmitted to the receiving station, and the receiving station transmits a block ACK to the transmitting station in response to the BAR.

[0070] The transmission timing adjustment unit 160 notifies, as adjustment processing different from the aforementioned ACK reply timing from the receiving station, the transmission completion timing TF at which data transmission is completed from each of the radio signal processing units 130, 140, and 150. The transmission completion timing TF is set based on the time required for data transmission from each of the radio signal processing units 130, 140, and 150. Each of the radio signal processing units 130, 140, and 150 adds dummy data for which data transmission is completed at the transmission completion timing TF notified by the transmission timing adjustment unit 160, for example. In this case, the addition of the dummy data is executed by the radio signal processing unit in which transmission is completed at a timing earlier than the transmission completion timing TF. In each of the radio signal processing units 130, 140, and 150, when data is transmitted to the receiving station, the data transmission is completed at the transmission completion timing TF. After the data reception is completed, the receiving station transmits an ACK to the transmitting station.

[0071] In an example shown in FIG. 12, the transmission timing adjustment unit 160 notifies the STA functions STA1 and STA2 of the data transmission completion timing TF. In this example, since the transmission completion timing TF1 of the STA function STA1 is earlier than the notified transmission completion timing TF, the STA function STA1 adds dummy data to the data to make the data transmission completion timing TF. On the other hand, since the transmission completion timing TF2 of the STA function STA2 coincides with the notified transmission completion timing TF, the STA function STA2 does not add dummy data to the data. Then, at the transmitting station, the STA function STA1 transmits the data with dummy data added, and the STA function STA2 transmits the data without dummy data added. At the receiving station, after the STA functions STA1 and STA2 receive the data, they transmit an ACK to the transmitting station.

[0072] Note that the transmission timing adjustment unit 160 can set the maximum value of the time required for the above-described data transmission, for example, at the start of channel access, by each radio signal processing unit notifying the transmission timing adjustment unit 160 of the timing of data transmission schedule and the timing of data transmission end. Each radio signal processing unit notifies the transmission timing adjustment unit 160 of the timing of data transmission schedule and the timing of data transmission end based on the update of the timing of data transmission schedule and the timing of data transmission end. Thereby, the transmission timing adjustment unit 160 can notify each radio signal processing unit of the latest maximum value of the time required for data transmission. Therefore, each radio signal processing unit transmits the above-described ACK reply timing and the like to the receiving station based on the latest maximum value of the time required for data transmission.

[0073] As described above, in the present embodiment, the transmission timing adjustment unit 160 adjusts the transmission timing of the first data related to the first radio signal processing unit and the second data related to the second radio signal processing unit based on the first status related to the first radio signal processing unit and the second status related to the second radio signal processing unit. Thereby, when both the first radio signal processing unit and the second radio signal processing unit attempt to transmit data in the present embodiment, even if there is mutual power leakage, the transmission timing of the data can be appropriately adjusted to avoid the influence of power leakage and appropriately transmit and receive data.

[0074] In the present embodiment, the transmission timing adjustment unit 160 manages the status of the channel access procedure (first status) of the first radio signal processing unit and the status of the channel access procedure (second status) of the second radio signal processing unit. Thereby, the transmission timing adjustment unit 160 can appropriately adjust the transmission timing of the data based on the first status and the second status.

[0075] In the present embodiment, when the first status indicates the completion of the channel access procedure, the transmission timing adjustment unit 160 checks the second status. Thereby, when the first radio signal processing unit attempts to transmit data, processing corresponding to the status of the second radio signal processing unit can be executed. In this way, the transmission timing adjustment unit 160 suppresses the execution of unnecessary operations by limiting the execution time of the operation of checking the second status.

[0076] In the present embodiment, when the first status indicates the completion of the channel access procedure and the second status indicates the execution of the channel access procedure, the transmission timing adjustment unit 160 notifies the first radio signal processing unit of an instruction to wait for data transmission. Thereby, even when there is mutual power leakage between the first radio signal processing unit and the second radio signal processing unit, it can be detected that the other radio signal processing unit attempts to transmit data, and the transmission timing of the radio signal processing units can be aligned.

[0077] In this embodiment, when the first status indicates the completion of the channel access procedure and the second status also indicates the completion of the channel access procedure, the transmission timing adjustment unit 160 notifies the first radio signal processing unit and the second radio signal processing unit of the data transmission instruction. Thereby, the first radio signal processing unit and the second radio signal processing unit can transmit data at an appropriate timing. By adjusting the timing of data transmission in this way, for example, a situation where the second radio signal processing unit cannot receive an ACK while the first radio signal processing unit is transmitting data can be avoided in advance.

[0078] In this embodiment, based on the maximum value of the time required for data transmission by the first radio signal processing unit and the second radio signal processing unit, the transmission timing adjustment unit 160 notifies the first radio signal processing unit and the second radio signal processing unit of either the same ACK reply timing, BAR reply timing, or the timing to complete data transmission. Thereby, even when the transmission times of the data transmitted from the first radio signal processing unit and the second radio signal processing unit are different, communication between the transmitting station and the receiving station can be appropriately executed. For example, a situation where the second radio signal processing unit cannot receive an ACK while the first radio signal processing unit is transmitting data can be avoided in advance.

[0079] In this embodiment, at the receiving station, based on the instruction of the ACK reply timing received from the transmitting station that transmits the radio signal, the first radio signal processing unit and the second radio signal processing unit reply an ACK to the transmitting station. Thereby, the receiving station can reply an ACK to the transmitting station at a timing that does not overlap with the data transmission timing of the transmitting station, for example.

[0080] [Modification Example 1] Hereinafter, a modification example of the embodiment will be described. FIG. 13 is a diagram showing a modification example of the functional configuration of the base station. As shown in FIG. 13, the transmission timing adjustment unit 160 included in the base station 10 may receive data to be transmitted from each of the radio signal processing units 130, 140, and 150. In this case, since the transmission timing adjustment unit 160 receives data from each radio signal processing unit, it does not notify each radio signal processing unit 130, 140, and 150 of transmission control information. Instead, the transmission timing adjustment unit 160 stores the data received from each radio signal processing unit, and based on the carrier sense status notified from each of the radio signal processing units 130, 140, and 150, transmits the data received from each radio signal processing unit. That is, the transmission timing adjustment unit 160 controls itself based on the transmission control information described in the embodiment to execute data transmission or data transmission standby.

[0081] In the case of this modification example, as shown in FIG. 14, after the channel access function of the radio signal processing unit 130 obtains the transmission right in the same manner as in the above-described embodiment, the extracted MAC frame is output to the transmission timing adjustment unit 160. Also in this modification example, the channel access functions of the radio signal processing units 140 and 150 are the same as the channel access function in the radio signal processing unit 130. Therefore, the transmission timing adjustment unit 160 cooperates with the STA functions of the radio signal processing units 130, 140, and 150 to generate a radio signal based on the input MAC frame. Then, the transmission timing adjustment unit 160 transmits the radio signal based on the carrier sense status of each radio signal processing unit.

[0082] FIG. 15 is a table showing an example of the transmission process of a radio signal in the radio system according to this modified example. Also in this modified example, when the completion of the channel access (CA) procedure is notified to the transmission timing adjustment unit 160 as the carrier sense (CS) situation, the transmission timing adjustment unit 160 checks the status management information of other radio signal processing units. At this time, if the status management information of all other radio signal processing units indicates the completion of the CA procedure, the transmission timing adjustment unit 160 transmits the data corresponding to all other radio signal processing units. If the status management information of at least one other radio signal processing unit indicates that the CA procedure is in progress, the transmission timing adjustment unit 160 waits for the transmission of the data corresponding to the radio signal processing unit whose status management information has been updated. When the start of the CA procedure is notified to the transmission timing adjustment unit 160 as the CS situation, the same processing as in the above-described embodiment is executed. When the cancellation of the CA procedure is notified to the transmission timing adjustment unit 160 as the CS situation, the transmission timing adjustment unit 160 clears the status management information of the radio signal processing unit that notified the CS situation. At this time, if the status management information of all other radio signal processing units indicates the completion of the CA procedure, the transmission timing adjustment unit 160 transmits the data corresponding to all other radio signal processing units.

[0083] Also in this modified example, the transmission timing adjustment unit 160 adjusts the transmission timing of the first data related to the first radio signal processing unit and the second data related to the second radio signal processing unit based on the first status related to the first radio signal processing unit and the second status related to the second radio signal processing unit. Therefore, the same effects as in the above-described embodiment are achieved.

[0084] [Modified Example 2] In the above-described embodiments and the like, it is assumed that the base station 10 is a transmitting station that transmits a radio signal and the terminal 20 is a receiving station that receives a radio signal. On the other hand, the technology of the embodiment can also be applied to a situation where the terminal 20 transmits a radio signal and the base station 10 receives a radio signal. That is, the relationship between the transmitting station and the receiving station described in the embodiment can be reversed.

[0085] [Other Modification Examples] Each process according to the above-described embodiment etc. may be stored as a program that can be executed by a CPU or the like which is a computer. In addition, it can be stored and distributed in a storage medium of an external storage device such as a magnetic disk, an optical disk, or a semiconductor memory. Then, a CPU or the like reads the program stored in the storage medium of this external storage device, and by controlling the operation according to this read program, the above-described process can be executed.

[0086] Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist thereof at the implementation stage. Also, each embodiment may be implemented in an appropriate combination, and in that case, the combined effects can be obtained. Further, the above-described embodiment includes various inventions, and various inventions can be extracted by combinations selected from a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, if the problem can be solved and the effect can be obtained, the configuration from which these constituent elements are deleted can be extracted as an invention. [Description of Reference Numerals]

[0087] 1... Wireless system 10... Base station 20... Terminal 30... Server 11, 21... CPU 12, 22... ROM 13, 23... RAM 14, 24... Wireless communication module 15... Wired communication module 25... Display 26... Storage 100, 200... Data processing unit 110, 210... MAC frame processing unit 120, 220... Management unit 121, 221... Link management information 122, 222... Association processing unit 123, 223... Authentication processing unit 130, 140, 150, 230, 240, 250... Wireless signal processing unit 131... Data categorization unit 132A, 132B, 132C, 132D... Transmission queue 133A, 133B, 133C, 133D... CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) execution unit 134... Data collision management unit 160... Transmission timing adjustment unit LM1, LM2... Link management unit

Claims

1. A first wireless signal processing unit that transmits and receives a wireless signal using a first channel; A second wireless signal processing unit that transmits and receives a wireless signal using a second channel different from the first channel; A transmission timing adjustment unit that adjusts the transmission timing of first data related to the first wireless signal processing unit and second data related to the second wireless signal processing unit; Comprising: The transmission timing adjustment unit adjusts the transmission timing of the first data and the second data based on a first status related to the channel access procedure of the first wireless signal processing unit and a second status related to the channel access procedure of the second wireless signal processing unit; The transmission timing adjustment unit determines the same reply timing of ACK for the first data and the second data whose transmission timing has been adjusted; Transmitting station.

2. The first status is the status of the channel access procedure of the first wireless signal processing unit; The second status is the status of the channel access procedure of the second wireless signal processing unit; The transmission timing adjustment unit manages the first status and the second status; The transmitting station according to Claim 1.

3. When the first status indicates completion of the channel access procedure, the transmission timing adjustment unit checks the second status; The transmitting station according to Claim 2.

4. When the second status indicates that the channel access procedure is in progress, the transmission timing adjustment unit notifies the first wireless signal processing unit of an instruction to wait for transmission of the first data; The transmitting station according to Claim 3.

5. When the second status indicates completion of the channel access procedure, the transmission timing adjustment unit notifies the first wireless signal processing unit and the second wireless signal processing unit of an instruction to transmit the first data and the second data; The transmitting station according to Claim 3.

6. The transmission timing adjustment unit receives the first data and the second data and transmits the first data and the second data; The transmitting station according to Claim 1.

7. The transmission timing adjustment unit notifies the first radio signal processing unit and the second radio signal processing unit of any one of the same reply timing of the ACK, the reply timing of a BAR (Block ACK request), or the timing to complete data transmission, based on the maximum value of the time required for data transmission by the first radio signal processing unit and the second radio signal processing unit. The transmitting station according to claim 1. **Claim 8** A first radio signal processing unit that transmits and receives radio signals using a first channel; A second radio signal processing unit that transmits and receives radio signals using a second channel different from the first channel; comprising Based on an instruction of the reply timing of an ACK received from the transmitting station according to claim 1 that transmits a radio signal, the first radio signal processing unit and the second radio signal processing unit reply an ACK to the transmitting station. Receiving station.

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