Transmitting station and receiving station

Abstract

To provide a transmitter station and a receiving station that improve the transmission of data when there is power leakage between the links when multiple links transmit data simultaneously.SOLUTION: In a wireless system, a base station, which is a station that transmits wireless signals, includes wireless signal processing units 130 to 150 and a transmission timing adjustment unit 160. Each of the wireless signal processing units transmits and receives wireless signals using one channel or different channels. The transmission timing adjustment unit adjusts the transmission timing of each data on the basis of the status associated with each of the wireless signal processing units.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The 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] The 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 the embodiment, when multiple links transmit data simultaneously, it is possible to provide a transmitting station and a receiving station that can improve data transmission when there is power leakage between the links. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 shows an example of the configuration of a wireless system according to an embodiment. [Figure 2] Figure 2 shows a specific example of the MAC frame format. [Figure 3] Figure 3 shows an example of a base station configuration. [Figure 4] Figure 4 shows an example of the functional configuration of a base station. [Figure 5] Figure 5 shows an example of a terminal configuration. [Figure 6] Figure 6 shows an example of the functional configuration of a terminal. [Figure 7] Figure 7 shows the details of the channel access function at the base station. [Figure 8] Figure 8 is a flowchart showing an example of multilink processing in a wireless system according to this embodiment. [Figure 9] Figure 9 shows an example of the transmission process of a wireless signal in a wireless system according to the embodiment. [Figure 10] Figure 10 illustrates the process of adjusting the timing of ACK responses when the data transmission times by the STA function differ. [Figure 11] Figure 11 illustrates a process that adjusts the timing of ACK responses when the data transmission times by the STA function differ, and is different from the process shown in Figure 10. [Figure 12] Figure 12 illustrates a process that adjusts the timing of ACK responses when the data transmission times by the STA function differ, and is a process that differs from that shown in Figures 10 and 11. [Figure 13]Figure 13 shows a modified example of the functional configuration of a base station. [Figure 14] Figure 14 shows a detailed example of a modified channel access function at a base station. [Figure 15] Figure 15 shows an example of the transmission process of a wireless signal in a wireless system according to a modified embodiment. [Modes for carrying out the invention]

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

[0009] Base station 10 is connected to a network NW and used as a wireless LAN access point. For example, base station 10 can wirelessly transmit data received from the network NW to terminal 20. Base station 10 can also connect to terminal 20 using one or more different channels. In this specification, a wireless connection between base station 10 and terminal 20 using multiple different channels is referred to as "multilink". Communication between base station 10 and terminal 20 is based on, for example, the IEEE 802.11 standard.

[0010] Terminal 20 is a wireless terminal such as a smartphone or tablet PC. Terminal 20 can send and receive data to and from a server 30 on the network NW via a wirelessly connected base station 10. Terminal 20 may also be other electronic devices such as a desktop computer or laptop computer. 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 data of content targeted at the terminal 20. The server 30 is, for example, wired-connected to the network NW and is 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, a LLC packet is formed by adding a DSAP (Destination Service Access Point) header, a SSAP (Source Service Access Point) header, etc. to the data input from a higher-level 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 regarding the first layer and the MAC sublayer of the second layer defined by the IEEE802.11 standard is mainly explained, and the explanation regarding the processing of other layers is omitted.

[0013] FIG. 2 shows a specific example of the format of a 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 FIG. 2, as fields included in the MAC frame, for example, there are a Frame Control field, a Duration field, an Address1 field, an Address2 field, an Address3 field, a Sequence Control field, an Address4 field, a QoS Control field, an HT Control field, a Frame Body field, and an FCS (Frame Check Sequence) field. Some of these fields are included and some are not depending on the type of the wireless frame.

[0014] 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 an error detection code for the MAC header and the Frame Body field. The FCS field is used to determine the presence or absence of an error in the MAC frame.

[0015] The Frame Control field contains various control information, for example, a Type value, a Subtype value, a To DS (Distribution System) value, a From DS value, and a 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, 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. And "00 / 0101 (Type value / Subtype value)" indicates that the MAC frame is a probe response.

[0017] The To DS value and 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. Similarly, 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 control frame, the To DS value and From DS value are fixed to, for example, "0".

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

[0019] The Duration field indicates the planned duration of use of the wireless connection. The Address field displays the BSSID, source MAC address, destination MAC address, sender terminal address, receiver terminal address, etc. The number of Address fields used varies depending on the frame type. The Sequence Control field displays the sequence number of the MAC frame and the fragment number for fragments. The QoS Control field is used for the Quality of Service (QoS) function in MAC frames. The QoS Control field may include a Traffic Type (TID) subfield. The HT Control field is a control field for high throughput functionality. The Frame Body field contains information corresponding to the frame type. For example, if the frame type is a data frame, the Frame Body field stores the transmitted data.

[0020] Figure 3 shows an example of the configuration of the base station 10. As shown in Figure 3, the base station 10 includes, for example, a CPU (Central Processing Unit) 11, ROM (Read Only Memory) 12, 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 the base station 10. The ROM 12 is a non-volatile semiconductor memory that holds programs and control data for controlling the base station 10. The RAM 13 is, for example, a volatile semiconductor memory and is used as a workspace for the CPU 11. The wireless communication module 14 is a circuit used for transmitting and receiving data via wireless signals and is connected to an antenna. The wireless communication module 14 also includes, for example, multiple communication modules corresponding to multiple frequency bands. The wired communication module 15 is a circuit used for transmitting and receiving data via wired signals and is connected to a 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, MAC frame processing unit 110, management unit 120, and radio signal processing units 130, 140, 150, and transmission timing adjustment unit 160 is realized, for example, by a CPU 11 and a wireless communication module 14.

[0023] The data processing unit 100 can perform LLC layer processing and higher layer (layers 3 to 7) processing on the input data. For example, the data processing unit 100 outputs data input from server 30 via network NW to MAC frame processing unit 110. The data processing unit 100 also sends data input from MAC frame processing unit 110 to server 30 via network NW.

[0024] The MAC frame processing unit 110 performs processing on the input data, for example, at the MAC layer. For example, the MAC frame processing unit 110 generates a MAC frame from the data input from the data processing unit 100. The MAC frame processing unit 110 also reconstructs data from the MAC frames input from the wireless signal processing units 130, 140, and 150, respectively. The processes of generating a MAC frame from data and reconstructing data from MAC frames may be based on the IEEE 802.11 standard.

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

[0026] Each of the wireless signal processing units 130, 140, and 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, and 150 adds a preamble, 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, and 150 converts the wireless frame into a wireless signal and distributes the wireless signal via the base station 10's antenna. Also, each of the wireless signal processing units 130, 140, and 150 converts the wireless signal received via the base station 10's antenna into a wireless frame. Then, each of the wireless signal processing units 130, 140, and 150 outputs the data contained in the wireless frame (for example, the MAC frame) to the MAC frame processing unit 110.

[0027] Thus, each of the wireless signal processing units 130, 140, and 150 can perform, for example, part of the MAC layer processing and the first layer processing on the input data or wireless signal. For example, the wireless signal processing units 130, 140, and 150 handle wireless signals in the 5GHz band. The wireless signal processing units 130, 140, and 150 may or may not share the antenna of the base station 10.

[0028] The transmission timing adjustment unit 160 adjusts the timing at which data is transmitted from each of the wireless signal processing units 130, 140, and 150. The transmission timing adjustment unit 160 is notified of the carrier sense status based on the carrier sense (CS) performed by each of the wireless signal processing units 130, 140, and 150. The transmission timing adjustment unit 160 manages the carrier sense status notified by each of the wireless signal processing units 130, 140, and 150 as status management information. Carrier sense is a process that detects the usage status of a channel, and determines whether the channel is unused (idle) or in use (busy) as the channel status. Carrier sense may be performed using, for example, CCA (Clear Channel Assessment). Each of the wireless signal processing units 130, 140, and 150 notifies the transmission timing adjustment unit 160 of the scheduled time to acquire transmission rights if the idle state continues based on carrier sense, and the status of the carrier sense. The carrier sense status corresponds to the status of the channel access procedure, such as the start of the channel access procedure, acquisition of transmission rights upon completion of the channel access procedure, or termination of the channel access procedure when a busy state is detected. Each of the wireless signal processing units 130, 140, and 150 notifies the transmission timing adjustment unit 160 of the carrier sense status based on the change in the carrier sense status.

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

[0030] Figure 5 shows an example of the configuration of terminal 20. As shown in Figure 5, terminal 20 includes, for example, a CPU 21, ROM 22, RAM 23, wireless communication module 24, display 25, and 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 that holds programs and control data for controlling the terminal 20. The RAM 23 is, for example, a volatile semiconductor memory and is used as the working area for the CPU 21. The wireless communication module 24 is a circuit used for sending and receiving data via wireless signals and is connected to an antenna. The wireless communication module 24 also includes, for example, multiple communication modules corresponding to multiple frequency bands. The display 25 displays, for example, a GUI (Graphical User Interface) corresponding to application software. The display 25 may also function as an input interface for the terminal 20. The storage 26 is a non-volatile storage device that holds, for example, the system software of the terminal 20. The terminal 20 does not necessarily have a display.

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

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

[0034] The MAC frame processing unit 210 performs, for example, MAC layer processing on the input data. The MAC frame processing unit 210 generates MAC frames from the data input from the data processing unit 200. The MAC frame processing unit 210 also reconstructs data from MAC frames input from the wireless signal processing units 230, 240, and 250, respectively. The processes of generating MAC frames from data and reconstructing data from MAC frames may be based on the IEEE 802.11 standard.

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

[0036] Each of the wireless signal processing units 230, 240, and 250 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 230, 240, and 250 adds a preamble, PHY header, etc., to the MAC frame input from the MAC frame processing unit 210 to create a wireless frame. Then, each of the wireless signal processing units 230, 240, and 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 wireless signal processing units 230, 240, and 250 converts the wireless signal received via the antenna of the terminal 20 into a wireless frame. Then, each of the wireless signal processing units 230, 240, and 250 outputs the data contained in the wireless frame (e.g., MAC frame) to the MAC frame processing unit 210.

[0037] Thus, each of the wireless signal processing units 230, 240, and 250 can perform, for example, part of the MAC layer processing and the first layer processing on the input data or wireless signal. For example, the wireless signal processing units 230, 240, and 250 handle wireless signals in the 5GHz band. The wireless signal processing units 230, 240, and 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 by each of the wireless signal processing units 230, 240, and 250. In addition, the transmission timing adjustment unit 260 notifies each of the wireless signal processing units 230, 240, and 250 of the transmission control information 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. Furthermore, the application execution unit 270 can operate based on the 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, wireless connections can be made 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 using the 5GHz band. In this specification, each of these wireless signal processing units may be referred to as an "STA function". In other words, the wireless system 1 according to the embodiment has multiple STA functions.

[0041] Figure 7 shows details of the channel access function in the radio signal processing unit of base station 10. In this embodiment, radio signal processing units 130, 140, and 150 each have a channel access function. Figure 7 shows the channel access function of radio signal processing unit 130. The channel access functions of radio signal processing units 140 and 150 are the same as those of radio signal processing unit 130. Therefore, a description of the channel access functions of radio signal processing units 140 and 150 is omitted. Similarly, the radio signal processing units 230, 240, and 250 of terminal 20 each have a channel access function. The channel access functions of radio signal processing units 230, 240, and 250 are the same as those of radio signal processing unit 130. Therefore, a description of the channel access functions of 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 this embodiment, for example, the channel access function is implemented using EDCA (Enhanced Distribution Channel Access).

[0043] The data categorization unit 131 categorizes the MAC frame data input from the MAC frame processing unit 110, for example, using a TID. The TID is assigned to each application (session) handled by the terminal 20 and represents the type of traffic. Examples of data categories include "VO (Voice)", "VI (Video)", "BE (Best Effort)", and "BK (Background)".

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

[0045] When data is input to any of the transmission queues 132A to D, 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 a carrier sense status. In addition to this notification, the CSMA / CA execution units 133A, 133B, 133C, and 133D also notify the transmission timing adjustment unit 160 of the scheduled time for completion of the channel access procedure. In CSMA / CA, each of the CSMA / CA execution units 133A, 133B, 133C, and 133D waits for a time specified by the pre-set access parameters, while confirming through carrier sense that there are no wireless signals being transmitted by other terminals, etc.

[0046] Once the channel access procedure is complete, 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 a 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 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 cancels the channel access procedure and notifies the transmission timing adjustment unit 160 of the cancellation of the channel access procedure as a carrier sense status.

[0047] Then, when the CSMA / CA execution units 133A, 133B, 133C, and 133D acquire the right to transmit, they retrieve MAC frames from the corresponding transmission queues 132A, 132B, 132C, and 132D, and output the retrieved MAC frames to the STA function via the data collision management unit 134. The STA function of the wireless signal processing unit 130 then generates a wireless signal based on the input MAC frame. The wireless signal processing unit 130 transmits the wireless signal based on the transmission control information notified by the transmission timing adjustment unit 160.

[0048] CSMA / CA execution unit 133A performs CSMA / CA on MAC frames containing VO data held in transmit queue 132A. CSMA / CA execution unit 133B performs CSMA / CA on MAC frames containing VI data held in transmit queue 132B. CSMA / CA execution unit 133C performs CSMA / CA on MAC frames containing BE data held in transmit queue 132C. CSMA / CA execution unit 133D performs CSMA / CA on MAC frames containing BK data held in transmit queue 132D.

[0049] In EDCA, access parameters are assigned in the order of priority for radio signal transmission, for example, VO, VI, BE, BK. Access parameters include, for example, CWmin, CWmax, AIFS, and TXOPLimit. CWmin and CWmax represent the minimum and maximum values ​​of the Contention Window (CW), which is the transmission waiting time for collision avoidance. AIFS (Arbitration Inter Frame Space) represents a fixed transmission waiting time set for each access category for collision avoidance control with priority control functionality. TXOPLimit represents the upper limit of Transmission Opportunity (TXOP), which corresponds to the channel occupancy time. For example, the shorter the CWmin and CWmax, the easier it is to obtain transmission rights in the transmission queue. The priority of the transmission queue increases as the AIFS value decreases. The amount of data transmitted in a single transmission right increases as the TXOPLimit value increases.

[0050] The data collision management unit 134 prevents data collisions when multiple CSMA / CA execution units acquire transmission rights with the same STA function. Specifically, the data collision management unit 134 adjusts the transmission timing of data that belong to different categories but have acquired transmission rights with the same STA function. The data collision management unit 134 transmits MAC frames containing data from the higher-priority category to the STA function first. For example, an STA function that has acquired transmission rights through CSMA / CA in VO transmission queue 132A may acquire transmission rights simultaneously with an STA function that has acquired transmission rights through CSMA / CA in any of the other transmission queues 132B to 132D. In this case, the data collision management unit 134 prioritizes transmitting the MAC frame stored in transmission queue 132A to the STA function. Similarly, in other combinations of transmission queues 132B to 132D, MAC frames are transmitted in an order based on the priority set for each category. This prevents collisions between data that have been assigned to transmit to the same STA function.

[0051] Next, an example of the operation related to multilink of the wireless system 1 according to the embodiment will be described. For the sake of brevity in the following description, the base station 10 and the terminal 20 will be assumed to establish multilink using two STA functions, STA1 and STA2, respectively.

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

[0053] Specifically, in step S10, the terminal 20 first sends a probe request to the base station 10. The probe request is a signal to confirm whether or not the base station 10 is present in the vicinity of the terminal 20. The Frame Control field of the probe request contains, for example, “00 / 0100 (Type value / Subtype value)”. When the base station 10 receives the probe request, it executes the process in step S11.

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

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

[0056] In step S13, the management unit 120 of the base station 10 performs a multilink association process using one STA function. Specifically, the base station 10 first performs the association process of the first STA function with the terminal 20. Then, once a wireless connection (link) is established with the first STA function, the management unit 120 of the base station 10 uses the first STA function, for which a link has been established, to perform the association process of the second STA function. In other words, an STA function with an established link is used for the association process of an STA function for which a link has not yet been established. Once the association processes of at least two STA functions are completed, the base station 10 establishes a multilink and performs the process in step S14.

[0057] Furthermore, a multilink may be established when a link is established in the first STA function. For example, the base station 10 and the terminal 20 can each notify each other of their multilink capabilities, the links to be multilinked, and the operation parameters for each link prior to the association process, thereby enabling the association for multilinking to be performed all at once. Specifically, when the first STA function starts the association, the management units 120 and 220 instruct the establishment of a multilink and specify the links to be multilinked. Then, the management units 120 and 220 each perform link association and manage these links as multilinks.

[0058] In step S14, the management unit 120 of the base station 10 updates the link management information 121. In this example, step S14 is executed after two links have been established, but the link management information 121 may be updated each time the link status is updated, or it may be updated when a multilink is established. Once a multilink is established and the link management information is updated, the base station 10 executes step S15.

[0059] In step S15, the base station 10 sends a multilink establishment response to the terminal 20. The multilink establishment response is a signal used by the base station 10 to respond to a multilink request from the terminal 20. The Frame Control field of the multilink establishment response contains, for example, “00 / 0001 (Type value / Subtype value)”. The management unit 220 of the terminal 20 recognizes that a multilink has been established with the base station 10 based on the receipt of the multilink establishment response. Upon receiving the multilink establishment response, the terminal 20 executes the process in step S16.

[0060] In 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 a multilink has been established with the base station 10. This completes the setup of the multilink in the wireless system 1 according to the embodiment, and wireless communication using the multilink becomes possible between the base station 10 and the terminal 20.

[0061] Figure 9 is a table showing an example of the radio signal transmission process in a wireless system according to the embodiment. Hereinafter, the base station 10 is assumed to be a transmitting station that transmits radio signals. In Figure 9, the processing condition is the condition that triggers the transmission timing adjustment unit 160 to execute a predetermined process. The status management information processing is the content of the processing that the transmission timing adjustment unit 160 executes on the status management information of each radio signal processing unit. The status of other radio signal processing units is the status management information of radio signal processing units other than the radio signal processing unit that notified the transmission timing adjustment unit 160 of the carrier sense status. The processing content is the content of the predetermined process that the transmission timing adjustment unit 160 executes. The processing target is the target on which the transmission timing adjustment unit 160 executes the predetermined process. That is, the transmission timing adjustment unit 160 executes the processing content on the processing target based on the fact that the processing condition has been met.

[0062] In this embodiment, one of the wireless signal processing units 130, 140, or 150 notifies the transmission timing adjustment unit 160 of the carrier sense (CS) status. If the transmission timing adjustment unit 160 is notified of the completion of the channel access (CA) procedure as the carrier sense status, the transmission timing adjustment unit 160 updates the status management information of the wireless signal processing unit that notified the carrier sense status to indicate the completion of the channel access procedure. The transmission timing adjustment unit 160 checks the status management information of wireless signal processing units other than the wireless signal processing unit that notified the carrier sense status (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. If 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 transmission timing adjustment unit 160 is notified of the start of a channel access procedure as a carrier sense status, the transmission timing adjustment unit 160 updates the status management information of the radio signal processing unit that notified the carrier sense status to indicate that the channel access procedure is in progress. At this time, the transmission timing adjustment unit 160 does not perform any processing related to the status management information of other radio signal processing units. For example, the transmission timing adjustment unit 160 does not perform any special processing on other radio signal processing units.

[0064] If the transmission timing adjustment unit 160 is notified of the cancellation of the channel access procedure as a carrier sense status, the transmission timing adjustment unit 160 clears the status management information of the radio signal processing unit that notified it of 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. 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 does not perform any 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 wireless signal processing units 130, 140, and 150 by notifying each of the wireless signal processing units of transmission control information based on predetermined conditions. Even when the data transmission timing of the wireless signal processing units 130, 140, and 150 is appropriately adjusted in this way, the time required to transmit data from each of the wireless signal processing units 130, 140, and 150 may differ. In this case, for example, if there is power leakage between multiple links, when data is being transmitted on the link corresponding to the wireless signal processing unit 130, an ACK cannot be received on the link corresponding to the wireless signal processing unit 140. As will be explained below, in this embodiment, the transmission timing adjustment unit 160 performs a process to adjust the timing of the ACK reply from the receiving station to the transmitting station, thereby appropriately adjusting the timing of the ACK reply from the receiving station to the transmitting station.

[0066] The transmission timing adjustment unit 160, as part of the adjustment process for the timing of the ACK reply from the receiving station, notifies each of the radio signal processing units 130, 140, and 150 of a common ACK reply timing based on the maximum time required for each of the radio signal processing units 130, 140, and 150 to transmit data. That is, the reply timing is equal to or greater than the maximum time required for each of the radio signal processing units 130, 140, and 150 to transmit data. Each of the radio signal processing units 130, 140, and 150 stores the aforementioned 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 sends an ACK to the transmitting station according to the ACK reply timing in the received MAC header. If, after adjusting the ACK reply timing as described above, 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 by taking into account a period equivalent to the maximum time required to transmit the data.

[0067] In the example shown in Figure 10, the data transmission time T1 of STA function STA1 is shorter than the data transmission time T2 of STA function STA2. In this case, the transmission timing adjustment unit 160 sets a value that is T2 or more after the start of data transmission as the ACK reply timing TR common to both STA function STA1 and STA function STA2. The transmission timing adjustment unit 160 then notifies STA function STA1 and STA2 of the ACK reply timing TR. In STA function STA1 and STA2, the transmitting station stores the ACK reply timing TR in the MAC header and sends it to the receiving station, and when the receiving station reaches the ACK reply timing TR, it sends an ACK to the transmitting station.

[0068] The transmission timing adjustment unit 160 notifies the radio signal processing units 130, 140, and 150 of the timing for sending a BAR (Block ACK Request) as a different adjustment process from the timing of the ACK reply from the receiving station. The BAR is used by the transmitting station to request an acknowledgment from the receiving station for frames that have been successfully received. Each of the radio signal processing units 130, 140, and 150 transmits a BAR to the receiving station according to the BAR transmission timing notified by the transmission timing adjustment unit 160. After receiving the BAR, the receiving station sends a response to the transmitting station using a block ACK. At this time, each of the radio signal processing units 130, 140, and 150 creates the BAR.

[0069] In the example shown in Figure 11, the transmission timing adjustment unit 160 notifies the transmitting station's STA functions STA1 and STA2 of the transmission timing TB of the BAR. The transmission timing TB is at least after the STA functions STA1 and STA2 have finished transmitting the data. When the transmission timing TB is reached, the STA functions STA1 and STA2 transmit the BAR to the receiving station, and the receiving station sends a block ACK to the transmitting station for the BAR.

[0070] The transmission timing adjustment unit 160, as an adjustment process different from the aforementioned adjustment process for the timing of the ACK reply from the receiving station, notifies each of the radio signal processing units 130, 140, and 150 of the transmission completion timing TF, which indicates the completion of data transmission. 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 example, at the transmission completion timing TF notified by the transmission timing adjustment unit 160, which indicates the completion of data transmission. In this case, the addition of dummy data is performed by the radio signal processing unit that completes transmission at an earlier timing than the transmission completion timing TF. Each of the radio signal processing units 130, 140, and 150 transmits data to the receiving station, and the data transmission is completed at the transmission completion timing TF. After the receiving station has finished receiving the data, it sends an ACK to the transmitting station.

[0071] In the example shown in Figure 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 STA function STA1 is earlier than the notified transmission completion timing TF, STA function STA1 adds dummy data to the data to set the data transmission completion timing to TF. On the other hand, since the transmission completion timing TF2 of STA function STA2 matches the notified transmission completion timing TF, STA function STA2 does not add dummy data to the data. Then, at the transmitting station, STA function STA1 transmits the data with the dummy data added, and STA function STA2 transmits the data without the dummy data added. At the receiving station, after STA functions STA1 and STA2 receive the data, they send an ACK to the transmitting station.

[0072] The transmission timing adjustment unit 160 can set the maximum time required to transmit the aforementioned data by, for example, when channel access begins, each radio signal processing unit notifies the transmission timing adjustment unit 160 of the timing for scheduled data transmission and the timing for the end of data transmission. Each radio signal processing unit notifies the transmission timing adjustment unit 160 of the timing for scheduled data transmission and the timing for the end of data transmission based on the updated timing. As a result, the transmission timing adjustment unit 160 can notify each radio signal processing unit of the latest maximum time required to transmit the data. Therefore, each radio signal processing unit transmits the aforementioned ACK reply timing, etc., to the receiving station based on the latest maximum time required to transmit the data.

[0073] As described above, in this 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. As a result, when both the first radio signal processing unit and the second radio signal processing unit attempt to transmit data, the transmitting station of this embodiment can appropriately adjust the data transmission timing even if there is power leakage between them, thereby avoiding the effects of power leakage and enabling proper transmission and reception of data.

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

[0075] In this embodiment, the transmission timing adjustment unit 160 checks the second status if the first status indicates completion of the channel access procedure. This allows the first wireless signal processing unit to execute processing corresponding to the status of the second wireless signal processing unit when it attempts to transmit data. In this way, the transmission timing adjustment unit 160 suppresses the execution of unnecessary operations by limiting the timing of the operation to check the second status.

[0076] In this embodiment, the transmission timing adjustment unit 160 notifies the first wireless signal processing unit of a data transmission waiting instruction when the first status indicates completion of the channel access procedure and the second status indicates execution of the channel access procedure. This makes it possible to detect that the other wireless signal processing unit is about to transmit data and synchronize the transmission timing of the wireless signal processing units, even if the first and second wireless signal processing units are leaking power from each other.

[0077] In this embodiment, the transmission timing adjustment unit 160 notifies the first and second wireless signal processing units of a data transmission instruction when the first status indicates completion of the channel access procedure and the second status also indicates completion of the channel access procedure. This allows the first and second wireless signal processing units to transmit data at the appropriate timing. By adjusting the timing of data transmission in this way, situations such as the second wireless signal processing unit being unable to receive an ACK while the first wireless signal processing unit is transmitting data can be avoided in advance.

[0078] In this embodiment, the transmission timing adjustment unit 160 notifies the first and second radio signal processing units of either the timing for sending the same ACK, the timing for sending a BAR, or the timing for completing data transmission, based on the maximum time required for data transmission by the first and second radio signal processing units. This ensures that communication between the transmitting and receiving stations can be properly performed even if the transmission times of the data sent from the first and second radio signal processing units are different. For example, it is possible to avoid situations where the second radio signal processing unit cannot receive an ACK while the first radio signal processing unit is transmitting data.

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

[0080] [Example 1] The following describes a modified version of the embodiment. Figure 13 shows a modified version of the base station's functional configuration. As shown in Figure 13, the transmission timing adjustment unit 160 of 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, the transmission timing adjustment unit 160 does not notify each of the radio signal processing units 130, 140, and 150 of transmission control information in order to receive data from each radio signal processing unit. Instead, the transmission timing adjustment unit 160 reserves the data received from each radio signal processing unit and transmits the data received from each radio signal processing unit based on the carrier sense status notified by each of the radio signal processing units 130, 140, and 150. That is, the transmission timing adjustment unit 160 controls itself based on the transmission control information described in the embodiment to perform data transmission or data transmission waiting.

[0081] In this modified example, as shown in Figure 14, the channel access function of the wireless signal processing unit 130 acquires transmission rights in the same manner as in the previously described embodiment, and then outputs the extracted MAC frame to the transmission timing adjustment unit 160. In this modified example as well, the channel access functions of the wireless signal processing units 140 and 150 are the same as the channel access function of the wireless signal processing unit 130. Therefore, the transmission timing adjustment unit 160 generates a wireless signal based on the input MAC frame by cooperating with the STA functions of the wireless signal processing units 130, 140, and 150. Then, the transmission timing adjustment unit 160 transmits the wireless signal based on the carrier sense status of each wireless signal processing unit.

[0082] Figure 15 is a table showing an example of the radio signal transmission process in the radio system according to this modified example. In this modified example as well, when the transmission timing adjustment unit 160 is notified of the completion of the channel access (CA) procedure as a carrier sense (CS) status, 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 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 to transmit data corresponding to the radio signal processing unit that updated its status management information. When the transmission timing adjustment unit 160 is notified of the start of the CA procedure as a CS status, it performs the same processing as in the above embodiment. When the transmission timing adjustment unit 160 is notified of the cancellation of the CA procedure as a CS status, the transmission timing adjustment unit 160 clears the status management information of the radio signal processing unit that notified the CS 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 transmits data corresponding to all other radio signal processing units.

[0083] In this modified example, the transmission timing adjustment unit 160 adjusts the transmission timing of the first data related to the first wireless signal processing unit and the second data related to the second wireless signal processing unit based on the first status related to the first wireless signal processing unit and the second status related to the second wireless signal processing unit. Therefore, it achieves the same effects as the embodiment described above.

[0084] [Differentiation 2] In the embodiments described above, the base station 10 is a transmitting station that transmits radio signals, and the terminal 20 is a receiving station that receives radio signals. On the other hand, the technology of the embodiments can also be applied in situations where the terminal 20 transmits radio signals and the base station 10 receives them. In other words, the relationship between the transmitting station and the receiving station described in the embodiments can be interchanged.

[0085] [Other variations] Each process according to the embodiments described above may be stored as a program that can be executed by a computer, such as a CPU. Alternatively, it can be stored and distributed on a storage medium such as a magnetic disk, optical disk, or semiconductor memory. The CPU can then read the program stored on the storage medium of the external storage device, and its operation is controlled by the read program, thereby enabling it to execute the aforementioned processes.

[0086] It should be noted that the present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. Furthermore, each embodiment may be combined as appropriate, and in that case, the combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be extracted by selecting combinations from the multiple constituent elements disclosed. For example, if the problem can be solved and effects obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, then the configuration with these deleted constituent elements can be extracted as an invention. [Explanation of Symbols]

[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 2 hours… storage 100,200…Data Processing Unit 110,210…MAC frame processing unit 120,220… Management Department 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 Department 132A, 132B, 132C, 132D… Transmit Queues 133A, 133B, 133C, 133D…CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) execution part 134...Data Conflict Management Department 160...Transmission timing adjustment unit LM1, LM2… Link Management Department

Claims

1. A base station that communicates with a terminal, A first wireless signal processing unit that communicates first data using a first link established with the terminal, The system includes a second wireless signal processing unit that communicates second data using a second link different from the first link established with the terminal, In the first wireless signal processing unit, When transmission rights are acquired according to the channel access procedure, the second radio signal processing unit makes a selection of whether or not to start transmitting the first data based on whether or not it has acquired transmission rights. The transmission of the first data occurs in parallel with the transmission of the second data in the second link, a first immediate response to the first data and a second immediate response to the second data are required, and if the duration of the transmission of the first data is shorter than the duration of the transmission of the second data, at least information for synchronizing the completion of the transmission of the first data and the completion of the transmission of the second data is added to the first data. The first immediate response is received at a time that does not overlap with either the first data or the second data. Base station.

2. A terminal that communicates with a base station, A first wireless signal processing unit that communicates first data using a first link established with the base station, The system includes a second wireless signal processing unit that communicates second data using a second link different from the first link established with the base station, At the aforementioned base station, When the third radio signal processing unit, which communicates the first data using the first link, acquires transmission rights according to the channel access procedure, a selection is made as to whether or not to start transmitting the first data, based on whether or not the fourth radio signal processing unit, which communicates the second data using the second link, has acquired transmission rights. The transmission of the first data occurs in parallel with the transmission of the second data in the second link, a first immediate response to the first data and a second immediate response to the second data are required, and if the duration of the transmission of the first data is shorter than the duration of the transmission of the second data, at least information for synchronizing the completion of the transmission of the first data and the completion of the transmission of the second data is added to the first data. In the first wireless signal processing unit, the first immediate response is transmitted at a timing that does not overlap with either the first data or the second data. Terminal.

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