Transmitting station and transmitting method

Abstract

A transmitting station and a transmitting method are provided for exchanging traffic so that a specific link is not occupied for a long period of time. [Solution] In a communication system, each of an access point and a terminal functioning as a transmitting station includes a first transmitting unit, a second transmitting unit, and a management unit. The management unit establishes a multilink with a receiving station, assigning a first channel to the first transmitting unit and a second channel to the second transmitting unit. The second transmitting unit starts carrier sensing processing for second data during an occupation period in which the first transmitting unit transmits first data, and if it acquires a transmission right through the carrier sensing processing, transmits the second data following the first data.

Description

[Technical Field]

[0001] The embodiments relate to a transmitting station and a transmitting method. [Background technology]

[0002] Wireless LAN (Local Area Network) is a well-known system that wirelessly connects access points and terminals. In a wireless LAN, access points and terminals perform carrier sensing based on CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) and exchange traffic when they acquire the right to transmit. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] IEEE P802.11beTM / D1.5, “35.3.17 Enhanced multi-link single radio operation”, March 18, 2022 Summary of the Invention [Problem to be solved by the invention]

[0004] When exchanging traffic, it is desirable to control transmission so that a particular link is not occupied for a long period of time.

[0005] The present invention has been made in light of the above circumstances, and its object is to provide a wireless communication environment in which traffic can be exchanged so that a specific link is not occupied for a long period of time. [Means for solving the problem]

[0006] A transmitting station according to one embodiment includes a first transmitting unit, a second transmitting unit, and a management unit. The management unit establishes a multilink with a receiving station, assigning a first channel to the first transmitting unit and a second channel to the second transmitting unit. The second transmitting unit is configured to start a carrier sensing process for second data during an occupation period in which the first transmitting unit transmits first data, and, if a transmission right is acquired through the carrier sensing process, to transmit the second data following the first data. [Effects of the Invention]

[0007] According to the embodiment, it is possible to provide a wireless communication environment in which traffic can be exchanged so that a particular link is not occupied for a long period of time. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing the configuration of a communication system according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing an example of link management information of the communication system according to the first embodiment. [Figure 3] FIG. 3 is a block diagram showing an example of a hardware configuration of an access point according to the first embodiment. [Figure 4] FIG. 4 is a block diagram showing an example of the hardware configuration of the terminal according to the first embodiment. [Figure 5] FIG. 5 is a block diagram showing an example of the functional configuration of the access point according to the first embodiment. [Figure 6] FIG. 6 is a block diagram illustrating an example of a functional configuration of a terminal according to the first embodiment. [Figure 7] FIG. 7 is a block diagram showing an example of a functional configuration related to cascade transmission processing of the radio signal processing unit according to the first embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of a cascade transmission process in the terminal according to the first embodiment. [Figure 9]FIG. 9 is a timing chart showing an example of the cascade transmission process in the terminal according to the first embodiment. [Figure 10] FIG. 10 is a block diagram showing the configuration of a communication system according to the second embodiment. [Figure 11] FIG. 11 is a block diagram illustrating an example of a functional configuration of a terminal according to the second embodiment. [Figure 12] FIG. 12 is a block diagram showing an example of a functional configuration related to cascade transmission processing of a radio signal processing unit according to the second embodiment. [Figure 13] FIG. 13 is a flowchart showing an example of a cascade transmission process in a terminal according to the second embodiment. [Figure 14] FIG. 14 is a timing chart showing an example of cascade transmission processing in the terminal according to the second embodiment. [Figure 15] FIG. 15 is a timing chart showing an example of cascade transmission processing in a terminal according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the following description, components having the same functions and configurations will be given the same reference numerals.

[0010] 1. First embodiment 1.1 Configuration 1.1.1 Communication Systems 1 is a block diagram showing an example of the configuration of a communication system according to the first embodiment. As shown in FIG. 1, the communication system 1 includes an access point 10, a terminal 20, and a network 30.

[0011] The access point 10 is, for example, a base station of a wireless LAN. The access point 10 is configured to communicate with a server (not shown) on the network 30 via wired or wireless communication. The access point 10 is configured to communicate with the terminal 20 via wireless communication. The communication between the access point 10 and the terminal 20 complies with, for example, the IEEE 802.11 standard.

[0012] The terminal 20 is, for example, a wireless terminal such as a smartphone or a PC (Personal Computer), etc. The terminal 20 is configured to communicate with a server on the network 30 via the access point 10.

[0013] The access point 10 and the terminal 20 have wireless communication functions based on, for example, the OSI (Open Systems Interconnection) reference model. In the OSI reference model, wireless communication functions are divided into seven layers (layer 1: physical layer, layer 2: data link layer, layer 3: network layer, layer 4: transport layer, layer 5: session layer, layer 6: presentation layer, and layer 7: application layer). The data link layer includes a Logical Link Control (LLC) sublayer and a Media Access Control (MAC) sublayer.

[0014] Multilink ML can be applied as a wireless connection method between the access point 10 and the terminal 20. Multilink ML is a wireless connection method that can transmit and receive data (exchange traffic) using multiple links simultaneously. The access point 10 and the terminal 20 to which Multilink ML is applied manage the state of Multilink ML using link management information.

[0015] 2 is a diagram showing an example of link management information of the communication system according to the first embodiment. The link management information includes, for example, information on a "link ID," a "link," a "frequency band," a "channel ID," a "multi-link," and "traffic."

[0016] A "link ID" is an identifier associated with an STA function. The STA function is a functional configuration that each of the access point 10 and the terminal 20 has in order to establish a link between the access point 10 and the terminal 20. That is, one pair of STA functions is used to establish one link. The example of FIG. 2 shows a case where three pairs of STA functions (STA1, STA2, and STA3) are assigned to wireless communication between the access point 10 and the terminal 20. The STA functions correspond to a wireless signal processing unit, which will be described later.

[0017] "Link" is information indicating whether or not a link has been established between the access point 10 and the terminal 20 by the STA function. The example of Fig. 2 shows a case where all of STA1, STA2, and STA3 have established links between the access point 10 and the terminal 20.

[0018] "Frequency band" is information indicating the frequency band used for the link. For example, the 2.4 GHz band, the 5 GHz band, and the 6 GHz band may be applied as the frequency band. Each frequency band includes multiple channels. In the example of FIG. 2, the 2.4 GHz band, the 5 GHz band, and the 6 GHz band are assigned to STA1, STA2, and STA3, respectively.

[0019] "Channel ID" is an identifier of the channel used for the link. In the example of Figure 2, STA1, STA2, and STA3 are assigned channels CH1 in the 2.4 GHz band, CH2 in the 5 GHz band, and CH3 in the 6 GHz band, respectively.

[0020] "Multilink" is information indicating whether or not a multilink ML has been established between the access point 10 and the terminal 20. In the example of Fig. 2, a case is shown in which a set of STA1, STA2, and STA3 has established a multilink ML.

[0021] "Traffic" is information indicating a TID (Traffic Indicator) assigned to an STA function. A TID is an identifier indicating each traffic, and may be associated with an access category. Access categories of traffic include, for example, "VO (Voice)," "VI (Video)," "BE (Best Effort)," "BK (Background)," and "LL (Low Latency)." Each of TIDs #1 to #4 in FIG. 2 corresponds to, for example, one of the access categories VO, VI, BE, BK, and LL. The example in FIG. 2 shows a case where TID #1 is assigned to STA1, STA2, and STA3. Also, a case where TIDs #2, #3, and #4 are further assigned to STA1, STA2, and STA3, respectively. In this way, in multilink ML, one or more STA functions can be assigned to one TID.

[0022] 1.1.2 Hardware Configuration Next, the hardware configuration of the access point and the terminal in the communication system according to the first embodiment will be described.

[0023] 1.1.2.1 Access point hardware configuration Fig. 3 is a block diagram showing an example of the hardware configuration of an access point according to the first embodiment. As shown in Fig. 3, the access point 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.

[0024] The CPU 11 is a processing circuit that controls the overall operation of the access point 10. The ROM 12 is, for example, a non-volatile semiconductor memory. The ROM 12 stores programs and data for controlling the access point 10. The RAM 13 is, for example, a volatile semiconductor memory. The RAM 13 is used as a working area for the CPU 11. The wireless communication module 14 is a circuit used to send and receive data by wireless signals. The wireless communication module 14 is connected to an antenna. The wired communication module 15 is a circuit used to send and receive data by wired signals. The wired communication module 15 is connected to the network 30.

[0025] 1.1.2.2 Terminal hardware configuration Fig. 4 is a block diagram showing an example of the hardware configuration of a terminal according to the first embodiment. As shown in Fig. 4, 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.

[0026] The CPU 21 is a processing circuit that controls the overall operation of the terminal 20. The ROM 22 is, for example, a non-volatile semiconductor memory. The ROM 22 stores programs and data for controlling the terminal 20. The RAM 23 is, for example, a volatile semiconductor memory. The RAM 23 is used as a working area for the CPU 21. The wireless communication module 24 is a circuit used for transmitting and receiving data via wireless signals. The wireless communication module 24 is connected to an antenna. The display 25 is, for example, an LCD (Liquid Crystal Display) or an EL (Electro-Luminescence) display. The display 25 displays a GUI (Graphical User Interface) corresponding to application software, etc. The storage 26 is a non-volatile storage device. The storage 26 stores system software, etc. of the terminal 20.

[0027] 1.1.3 Functional Configuration Next, the functional configurations of the access point and the terminal in the communication system according to the first embodiment will be described.

[0028] 1.1.3.1 Access point functional configuration FIG. 5 is a block diagram showing an example of the functional configuration of the access point according to the first embodiment.

[0029] The access point 10 functions as a computer including an LLC processing unit 110, a data processing unit 120, a management unit 130, a MAC frame processing unit 140, and multiple radio signal processing units 150, 160, and 170. The LLC processing unit 110 is a functional block that executes processing corresponding to the LLC sublayer of the second layer and layers 3 to 7. The data processing unit 120, the management unit 130, and the MAC frame processing unit 140 are functional blocks that execute processing corresponding to the MAC sublayer of the second layer. The multiple radio signal processing units 150, 160, and 170 are functional blocks that execute processing corresponding to the MAC sublayer of the second layer and layer 1.

[0030] The LLC processing unit 110 generates LLC packets by, for example, adding a DSAP (Destination Service Access Point) header, an SSAP (Source Service Access Point) header, etc. to data received from the network 30. The LLC processing unit 110 then inputs the generated LLC packets to the data processing unit 120. The LLC processing unit 110 also extracts data from the LLC packets input from the data processing unit 120. The LLC processing unit 110 then transmits the extracted data to the network 30.

[0031] The data processing unit 120 generates a MAC frame by adding a MAC header to the LLC packet input from the LLC processing unit 110. The data processing unit 120 then inputs the generated MAC frame to the MAC frame processing unit 140. The data processing unit 120 also extracts the LLC packet from the MAC frame input from the MAC frame processing unit 140. The data processing unit 120 then inputs the extracted LLC packet to the LLC processing unit 110. Hereinafter, a MAC frame containing data will also be referred to as a "data frame."

[0032] The management unit 130 manages the state of the link between the access point 10 and the terminal 20. MAC frames including management information related to the link are input and output between the management unit 130 and the MAC frame processing unit 140. Hereinafter, the MAC frame including the management information is also referred to as a "management frame." The management unit 130 includes link management information 131 and a link management unit 132.

[0033] The link management information 131 is information relating to the link between the access point 10 and the wirelessly connected terminal 20. The link management information 131 includes, for example, the information shown in FIG.

[0034] The link management unit 132 controls the establishment of a link with the terminal 20. For example, the link management unit 132 executes association processing and subsequent authentication processing in response to a connection request from the terminal 20. The link management unit 132 controls the state of the link established with the terminal 20. For example, the link management unit 132 can determine the association between a TID and an STA function when establishing a multilink ML.

[0035] When a MAC frame is input from the data processing unit 120 or the management unit 130, the MAC frame processing unit 140 associates the MAC frame with a link. For example, when a MAC frame is input from the data processing unit 120, the MAC frame processing unit 140 identifies the link associated with the TID included in the MAC header by referring to the link management information 131. The MAC frame processing unit 140 then inputs the MAC frame to the radio signal processing unit corresponding to the identified link. Furthermore, when a MAC frame is input from multiple radio signal processing units 150, 160, and 170, the MAC frame processing unit 140 inputs the MAC frame to the data processing unit 120 or the management unit 130 depending on the type of MAC frame. Specifically, if the MAC frame is a data frame, the MAC frame processing unit 140 inputs the MAC frame to the data processing unit 120. If the MAC frame is a management frame, the MAC frame processing unit 140 inputs the MAC frame to the management unit 130.

[0036] When a data frame is input from the data processing unit 120, the MAC frame processing unit 140 determines whether the frame size of the data frame is equal to or greater than a threshold value α. The threshold value α is, for example, a positive real number. If the frame size is equal to or greater than the threshold value α, the MAC frame processing unit 140 fragments the data frame to generate multiple data frames, each with a frame size less than the threshold value α. The MAC frame processing unit 140 associates the generated multiple data frames with multiple links that are different from one another. The MAC frame processing unit 140 then inputs the corresponding data frame to the radio signal processing unit corresponding to the identified link.

[0037] The transmission order k of the multiple data frames generated by the fragmentation process is associated with, for example, the fragment number FN. For the sake of convenience, it is assumed below that the data frame with fragment number FN=k is the kth data frame to be transmitted. The transmission order k is a number between 1 and k. M The integer k is Mis the number of data frames generated by the fragmentation process.

[0038] The multiple radio signal processing units 150, 160, and 170 correspond to STA1, STA2, and STA3 in the multilink ML shown in FIG. 2, respectively. The multiple radio signal processing units 150, 160, and 170 have the same functional configuration. Each of the multiple radio signal processing units 150, 160, and 170 generates a radio frame by adding a preamble or the like to the MAC frame input from the MAC frame processing unit 140. Each of the multiple radio signal processing units 150, 160, and 170 converts the generated radio frame into a radio signal. Then, each of the multiple radio signal processing units 150, 160, and 170 radiates (transmits) the converted radio signal via an antenna. The conversion process from the radio frame to the radio signal includes, for example, convolutional coding, interleaving, subcarrier modulation, inverse fast Fourier transform, Orthogonal Frequency Division Multiplexing (OFDM) modulation, and frequency conversion. Each of the multiple radio signal processing units 150, 160, and 170 converts a radio signal received from terminal 20 via an antenna into a radio frame. The conversion process from a radio signal to a radio frame includes, for example, frequency conversion, OFDM demodulation, fast Fourier transform, subcarrier demodulation, deinterleaving, and Viterbi decoding. Each of the multiple radio signal processing units 150, 160, and 170 extracts a MAC frame from the converted radio frame. Then, each of the multiple radio signal processing units 150, 160, and 170 inputs the extracted MAC frame to the MAC frame processing unit 140.

[0039] When multiple data frames generated by fragmentation processing are input, the multiple radio signal processing units 150, 160, and 170 cooperate with each other to execute cascade transmission processing. Cascade transmission processing is processing for continuously transmitting multiple fragmented data frames. Details of the cascade transmission processing will be described later.

[0040] 1.1.3.2 Terminal Functional Configuration FIG. 6 is a block diagram illustrating an example of a functional configuration of a terminal according to the first embodiment.

[0041] The terminal 20 functions as a computer including an application execution unit 200, an LLC processing unit 210, a data processing unit 220, a management unit 230, a MAC frame processing unit 240, and multiple radio signal processing units 250, 260, and 270. The application execution unit 200 is a functional block that executes processing corresponding to layer 7. The LLC processing unit 210 is a functional block that executes processing corresponding to the LLC sublayer of layer 2 and layers 3 to 6. The data processing unit 220, the management unit 230, and the MAC frame processing unit 240 are functional blocks that execute processing corresponding to the MAC sublayer of layer 2. The multiple radio signal processing units 250, 260, and 270 are functional blocks that execute processing corresponding to the MAC sublayer of layer 2 and layer 1.

[0042] The application execution unit 200 executes an application based on data input from the LLC processing unit 210. The application execution unit 200 also inputs data to the LLC processing unit 210. For example, the application execution unit 200 can display application information on the display 25. The application execution unit 200 can also operate based on operations on an input interface.

[0043] The LLC processing unit 210 generates an LLC packet by adding a DSAP header, an SSAP header, etc. to the data input from the application execution unit 200. Then, the LLC processing unit 210 inputs the generated LLC packet to the data processing unit 220. The LLC processing unit 210 also extracts data from the LLC packet input from the data processing unit 220. Then, the LLC processing unit 210 inputs the extracted data to the application execution unit 200.

[0044] The data processing unit 220 generates a MAC frame by adding a MAC header to the LLC packet input from the LLC processing unit 210. The data processing unit 220 then inputs the generated MAC frame to the MAC frame processing unit 240. The data processing unit 220 also extracts an LLC packet from the MAC frame input from the MAC frame processing unit 240. The data processing unit 220 then inputs the extracted LLC packet to the LLC processing unit 210.

[0045] The management unit 230 manages the state of the link between the access point 10 and the terminal 20. MAC frames including management information related to the link are input and output between the management unit 230 and the MAC frame processing unit 240. The management unit 230 includes link management information 231 and a link management unit 232.

[0046] The link management information 231 is information relating to the link between the terminal 20 and the wirelessly connected access point 10. The link management information 231 includes, for example, the information shown in FIG.

[0047] The link management unit 232 controls the establishment of a link with the access point 10. For example, the link management unit 232 executes an association process and a subsequent authentication process when transmitting a connection request to the access point 10. The link management unit 232 controls the state of the link established with the access point 10. For example, the link management unit 232 can determine the association between a TID and an STA function when establishing a multilink ML.

[0048] When a MAC frame is input from the data processing unit 220 or the management unit 230, the MAC frame processing unit 240 associates the MAC frame with a link. For example, when a MAC frame is input from the data processing unit 220, the MAC frame processing unit 240 identifies the link associated with the TID included in the MAC header by referring to the link management information 231. The MAC frame processing unit 240 then inputs the MAC frame to the radio signal processing unit corresponding to the identified link. Furthermore, when a MAC frame is input from multiple radio signal processing units 250, 260, and 270, the MAC frame processing unit 240 inputs the MAC frame to the data processing unit 220 or the management unit 230 depending on the type of MAC frame. Specifically, if the MAC frame is a data frame, the MAC frame processing unit 240 inputs the MAC frame to the data processing unit 220. If the MAC frame is a management frame, the MAC frame processing unit 240 inputs the MAC frame to the management unit 230.

[0049] When a data frame is input from the data processing unit 220, the MAC frame processing unit 240 determines whether the frame size of the data frame is equal to or greater than threshold value α. If the frame size is equal to or greater than threshold value α, the MAC frame processing unit 240 fragments the data frame to generate multiple data frames, each with a frame size less than threshold value α. The MAC frame processing unit 240 then associates the generated multiple data frames with multiple, mutually different links. The MAC frame processing unit 240 then inputs the corresponding data frame to the radio signal processing unit corresponding to the identified link.

[0050] The multiple radio signal processing units 250, 260, and 270 correspond to STA1, STA2, and STA3 in the multilink ML shown in FIG. 2, respectively. The multiple radio signal processing units 250, 260, and 270 have the same functional configuration. Each of the multiple radio signal processing units 250, 260, and 270 generates a radio frame by adding a preamble or the like to the MAC frame input from the MAC frame processing unit 240. Each of the multiple radio signal processing units 250, 260, and 270 converts the generated radio frame into a radio signal. Then, each of the multiple radio signal processing units 250, 260, and 270 radiates (transmits) the converted radio signal via an antenna. The conversion process from the radio frame to the radio signal includes, for example, convolutional coding, interleaving, subcarrier modulation, inverse fast Fourier transform, OFDM modulation, and frequency conversion. Each of the multiple radio signal processing units 250, 260, and 270 converts a radio signal received from the access point 10 via an antenna into a radio frame. The conversion process from the radio signal to the radio frame includes, for example, frequency conversion, OFDM demodulation, fast Fourier transform, subcarrier demodulation, deinterleaving, and Viterbi decoding. Each of the multiple radio signal processing units 250, 260, and 270 extracts a MAC frame from the converted radio frame. Then, each of the multiple radio signal processing units 250, 260, and 270 inputs the extracted MAC frame to the MAC frame processing unit 240.

[0051] When multiple data frames generated by fragmentation processing are input, the multiple wireless signal processing units 250, 260, and 270 cooperate with each other to perform cascade transmission processing. The cascade transmission processing in the terminal 20 is the same as the cascade transmission processing in the access point 10.

[0052] 1.1.3.3 Functional configuration related to cascade transmission processing Next, a functional configuration related to the cascade transmission process of each of the access point 10 and the terminal 20 according to the first embodiment will be described. When executing the cascade transmission process, each of the access point 10 and the terminal 20 functions as a transmitting station. Specifically, when the access point 10 executes the cascade transmission process, each of the radio signal processing units 150, 160, and 170 functions as a transmitting unit. When the terminal 20 executes the cascade transmission process, each of the radio signal processing units 250, 260, and 270 functions as a transmitting unit. Below, as an example, a functional configuration related to the cascade transmission process of the terminal 20 will be described.

[0053] Fig. 7 is a block diagram showing an example of the functional configuration related to the cascade transmission processing of the radio signal processing unit according to the first embodiment. Fig. 7 shows an example of the functional configuration related to the cascade transmission processing of the radio signal processing unit 250. Note that the functional configuration related to the cascade transmission processing of each of the radio signal processing units 260 and 270 is the same as the functional configuration related to the cascade transmission processing of the radio signal processing unit 250, and therefore a description thereof will be omitted.

[0054] The radio signal processing unit 250 includes a classification unit 251, a plurality of queues 252A, 252B, 252C, and 252D, a plurality of carrier sense units 253A, 253B, 253C, and 253D, and an internal collision management unit 254.

[0055] When a data frame divided by fragmentation processing is input from MAC frame processing unit 240, classification unit 251 classifies the data frame into a plurality of access categories based on the TID included in the MAC header. Then, classification unit 251 inputs the data frame to a corresponding queue 252 out of a plurality of queues 252A, 252B, 252C, and 252D. In the example of Fig. 7, classification unit 251 inputs data frames corresponding to access categories VO, VI, BE, and BK to queues 252A, 252B, 252C, and 252D, respectively.

[0056] Each of the multiple queues 252A, 252B, 252C, and 252D buffers input data frames. In the example of Figure 7, the multiple queues 252A, 252B, 252C, and 252D buffer data frames corresponding to the access categories VO, VI, BE, and BK, respectively.

[0057] The multiple carrier sense units 253A, 253B, 253C, and 253D correspond to the multiple queues 252A, 252B, 252C, and 252D, respectively. Each of the multiple carrier sense units 253A, 253B, 253C, and 253D performs carrier sense processing based on CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) in accordance with preset access parameters. The carrier sense processing includes a state determination process for determining the state of the channel used by the link and a standby process for waiting for a predetermined period of time to avoid collisions. If the carrier sense processing determines that the channel is idle for the predetermined period of time, each of the multiple carrier sense units 253A, 253B, 253C, and 253D acquires the right to transmit a data frame and terminates the carrier sense processing. If the channel is determined to be busy, each of the multiple carrier sense units 253A, 253B, 253C, and 253D cancels the acquisition of the right to transmit and terminates the carrier sense processing.

[0058] Access parameters used in carrier sense processing include, for example, CWmin, CWmax, AIFS (Arbitration Inter Frame Space), and TXOP (Transmission Opportunity) Limit. CWmin and CWmax respectively indicate the minimum and maximum values ​​of the contention window. The contention window is a parameter used to calculate backoff, which is a transmission waiting time for collision avoidance. AIFS is a fixed transmission waiting time set for each access category. TXOPLimit indicates the upper limit of the channel occupation period TXOP. In other words, the shorter the CWmin, CWmax, and AIFS set for an access category, the easier it is to obtain the transmission right. Furthermore, the larger the TXOPLimit set for an access category, the larger the amount of data that can be transmitted with one transmission right.

[0059] The carrier sense unit 253 corresponding to the fragmented data frame extracts the transmission order k of the data frame in the cascade transmission process by referring to the fragment number FN in the data frame. Then, the carrier sense unit 253 determines the execution timing of the carrier sense process for the data frame based on the transmission order k.

[0060] Specifically, when the extracted transmission order k is "1", the carrier sense unit 253 immediately executes carrier sense processing. Then, the carrier sense unit 253 calculates the TXOP end time γ1 of the data frame and transmits it to the other radio signal processors 260 and 270.

[0061] If the extracted transmission order k is not "1", the carrier sense unit 253 waits until it receives the TXOP end time γ(k-1) of the data frame with transmission order (k-1). Upon receiving the TXOP end time γ(k-1), the carrier sense unit 253 calculates the collision avoidance start time δk based on the TXOP end time γ(k-1). The collision avoidance start time δk is set, for example, to be a time that precedes the TXOP end time γ(k-1) by the sum of the average value of the DIFS (Distributed Coordination Function (DCF) Inter Frame Space) and the backoff. The carrier sense unit 253 performs carrier sense processing so that it can start standby processing at the collision avoidance start time δk. Then, the carrier sense unit 253 calculates the TXOP end time γk of the data frame to be transmitted k-th, and transmits the calculated time to the other radio signal processors 260 and 270.

[0062] In this way, carrier sense processing in the corresponding radio signal processing unit is executed sequentially according to the transmission order k. The carrier sense unit 253 that has acquired the transmission right extracts the data frame buffered in the corresponding queue 252. The carrier sense unit 253 that has acquired the transmission right inputs the extracted data frame to the internal collision management unit 254.

[0063] The internal collision management unit 254 prevents transmission collisions when two or more carrier sense units simultaneously acquire the transmission right. Specifically, for example, when multiple data frames are input simultaneously, the internal collision management unit 254 prioritizes transmission of data frames of higher priority access categories.

[0064] 1.2 Operation Next, the operation of the transmitting station in the communication system according to the first embodiment will be described.

[0065] When the access point 10 is a receiving station, the terminal 20 is a transmitting station. When the terminal 20 is a receiving station, the access point 10 is a transmitting station. In the following, as an example, a case where the terminal 20 is a transmitting station will be described. Note that in the following, it is assumed that a multilink ML based on the link management information shown in FIG. 2 has been established between the access point 10 and the terminal 20.

[0066] 1.2.1 Cascade transmission process flowchart Fig. 8 is a flowchart showing an example of cascade transmission processing in the transmitting station according to the first embodiment. Hereinafter, processing executed by one radio signal processing unit 250 corresponding to the function of one STA in the cascade transmission processing will be described with reference to Fig. 8. Note that processing executed by radio signal processing units 260 and 270 corresponding to the functions of other STAs in the cascade transmission processing is the same as that in the case of the radio signal processing unit 250.

[0067] When a fragmented data frame is buffered in queue 252 (start), carrier sense unit 253 extracts the transmission order k of the data frame (S1). Specifically, for example, carrier sense unit 253 extracts the transmission order k by referring to the fragment number FN of the data frame.

[0068] Carrier sense unit 253 determines whether transmission order k extracted in the process of S1 is the first (=1) (S2). That is, carrier sense unit 253 determines whether fragment number FN is "1".

[0069] If the transmission order k is the first (S2; yes), the carrier sense unit 253 immediately starts carrier sense processing (S3).

[0070] When the carrier sense process of S3 is executed, the carrier sense unit 253 calculates the TXOP end time γ1 (S4).

[0071] If the transmission order k is not the first (S2; no), the carrier sense unit 253 waits until the TXOP end time γ(k−1) is calculated in the other radio signal processing unit 260 or 270 (S5).

[0072] When the TXOP end time γ(k−1) is calculated, the carrier sense unit 253 calculates the collision avoidance start time Δk based on the TXOP end time γ(k−1) (S6).

[0073] The carrier sense unit 253 starts carrier sense processing so as to match the collision avoidance start time Δk calculated in the processing of S6 (S7). That is, the carrier sense unit 253 starts carrier sense processing so that standby processing can start at the collision avoidance start time Δk.

[0074] When the carrier sense process of S7 is executed, the carrier sense unit 253 calculates the TXOP end time γk (S8).

[0075] The carrier sense unit 253 determines whether or not the transmission right has been acquired through the carrier sense process of S3 or S7 (S9).

[0076] If the transmission right is acquired (S9; yes), the carrier sense unit 253 determines whether the transmission order k is the first or whether the current time has passed the TXOP end time γ(k−1) (S10).

[0077] If the transmission sequence k is not the first and the current time has not passed the TXOP end time γ(k-1) (S10; no), the carrier sense unit 253 waits until the DIFS period has passed since the TXOP end time γ(k-1) (S11). This allows the carrier sense unit 253 to reconfirm whether or not the data frame can actually be transmitted.

[0078] After the process of S11, or if the transmission order k is the first or the current time has passed the TXOP end time γ(k−1) (S10; yes), the wireless signal processing unit 250 starts the transmission process (S12). The transmission process includes transmitting a data frame and receiving an Ack (Acknowledgement) for the data frame.

[0079] If the transmission right cannot be acquired (S9; no), the radio signal processing unit 250 postpones the transmission process (S13).

[0080] After the process of S12 or S13, the cascade transmission process in the radio signal processing unit 250 ends (END).

[0081] 1.2.2 Cascade Send Processing Example 9 is a timing chart showing an example of cascade transmission processing in a transmitting station according to the first embodiment. In FIG. 9, a case is shown in which a data frame is transmitted first by the STA function corresponding to STA1, a data frame is transmitted second by the STA function corresponding to STA2, and a data frame is transmitted third by the STA function corresponding to STA3. Hereinafter, the STA functions corresponding to STA1, STA2, and STA3 will be simply referred to as "STA1," "STA2," and "STA3," respectively.

[0082] STA1 extracts the first transmission order k (=1) from the input data frame. STA1 then promptly performs carrier sensing. STA1 then calculates the TXOP end time γ1 during the carrier sensing process and transmits it to STA2 and STA3. After that, when STA1 acquires the transmission right through the carrier sensing process, it starts transmission processing.

[0083] Meanwhile, STA2 extracts the second transmission order k (=2) from the input data frame. STA3 extracts the third transmission order k (=3) from the input data frame. Accordingly, STA2 and STA3 wait until they receive the TXOP end times γ1 and γ2, respectively.

[0084] When STA2 receives the TXOP end time γ1, it calculates the collision avoidance start time δ2 and starts carrier sensing so that it matches the collision avoidance start time δ2. This allows STA2 to start standby processing at least by the TXOP end time γ1. STA2 also calculates the TXOP end time γ2 during carrier sensing and transmits it to STA1 and STA3.

[0085] When STA2 acquires the transmission right through the carrier sense process, it determines whether the current time has passed the TXOP end time γ1. In the example of FIG. 9, the TXOP end time γ1 has not passed when STA2 acquires the transmission right. In this case, STA2 waits until the DIFS period has passed since the TXOP end time γ1 to reconfirm that no collision will occur. Then, when it is confirmed that no collision will occur, STA2 starts the transmission process.

[0086] When STA3 receives the TXOP end time γ2, it calculates the collision avoidance start time δ3 and starts carrier sense processing so as to match the collision avoidance start time δ3. This allows STA3 to start at least standby processing by the TXOP end time γ2.

[0087] When STA3 acquires the transmission right through carrier sense processing, it determines whether the current time has passed the TXOP end time γ2. In the example of Figure 9, the TXOP end time γ2 has passed when STA3 acquires the transmission right. In this case, STA3 immediately starts transmission processing.

[0088] When the transmission process by STA3 is completed, the cascade transmission process is completed.

[0089] 1.3 Effects of the First Embodiment According to the first embodiment, the STA function of transmission order k starts carrier sensing processing while the STA function of transmission order (k-1) is exchanging traffic. More specifically, the STA function of transmission order k starts carrier sensing processing so that it can start collision avoidance processing earlier than the TXOP end time γ(k-1) by the sum of the average values ​​of DIFS and backoff. The STA function of transmission order k that has acquired the transmission right starts traffic exchange following the traffic exchange of the STA function of transmission order (k-1). This increases the probability that the STA function of transmission order k will acquire the transmission right after the traffic exchange of the STA function of transmission order (k-1) ends. This shortens the gap between traffic exchanges on different links, thereby suppressing degradation of delay characteristics. Furthermore, using multiple links allows large volumes of data to be distributed across multiple links. This prevents a specific link from being occupied for a long period of time.

[0090] Furthermore, if a STA function acquires a transmission right before the TXOP end time γ(k-1), the STA function of transmission order k waits until the DIFS period has elapsed since the TXOP end time γ(k-1) before starting transmission processing. This allows the STA function of transmission order k to check again at the TXOP end time γ(k-1) whether a collision with other traffic will occur on the link where the STA function acquired the transmission right. This makes it possible to more reliably avoid collisions.

[0091] Furthermore, if a transmission right is acquired after the TXOP end time γ(k-1), the STA function of transmission order k immediately starts transmission processing without additional waiting. This shortens the gap between traffic exchanges on different links. Therefore, the degradation of delay characteristics can be suppressed.

[0092] Furthermore, if the frame size of a data frame is equal to or greater than threshold α, the MAC frame processing unit 240 performs fragmentation processing. Through fragmentation processing, the MAC frame processing unit 240 generates multiple data frames with frame sizes less than threshold α. This allows multiple STA functions to perform cascade transmission processing on multiple data frames with frame sizes less than threshold α. This allows large volumes of data to be distributed across multiple links, thereby preventing a specific link from being occupied for a long period of time.

[0093] Furthermore, each of the multiple data frames generated by the fragmentation process contains a different fragment number FN, which allows the STA function to extract the transmission order k of the input data frame by referencing the fragment number FN of the input data frame.

[0094] 2. Second embodiment In the first embodiment, a case has been described in which a transmitting station has multiple radio signal processing units, and individual links are assigned to each of the multiple radio signal processing units. The second embodiment differs from the first embodiment in that a transmitting station has one radio signal processing unit, and multiple links are assigned to the one radio signal processing unit. The following mainly describes configurations and operations that differ from the first embodiment. Descriptions of configurations and operations that are equivalent to those of the first embodiment will be omitted as appropriate.

[0095] 2.1 Communication Systems 10 is a block diagram showing an example of the configuration of a communication system according to the second embodiment. As shown in FIG. 10, the communication system 1A includes an access point 10, a terminal 20A, and a network 30.

[0096] The terminal 20A is, for example, a wireless terminal such as a smartphone, a PC, etc. The terminal 20A is configured to communicate with a server on the network 30 via the access point 10.

[0097] In the wireless connection between the access point 10 and the terminal 20A, a link set LS consisting of a plurality of links is established. Each of the plurality of links in the link set LS is established using an STA function provided as a functional configuration in each of the access point 10 and the terminal 20A. The access point 10 is provided with a plurality of STA functions, while the terminal 20A is provided with one STA function.

[0098] To establish one link, one of the multiple STA functions of the access point 10 and the STA function of the terminal 20A are used. Therefore, to establish each of the multiple links of the link set LS, a corresponding one of the multiple STA functions of the access point 10 and the STA function of the terminal 20A are used. Therefore, the only STA function provided in the terminal 20A is used to establish all of the links that make up the link set LS.

[0099] 2.2 Terminal Functional Configuration Fig. 11 is a block diagram showing an example of the functional configuration of a terminal according to the second embodiment, which corresponds to Fig. 6 in the first embodiment.

[0100] Terminal 20A functions as a computer including an application execution unit 200, LLC processing unit 210, data processing unit 220, management unit 230, MAC frame processing unit 240, and radio signal processing unit 250A. The configurations of application execution unit 200, LLC processing unit 210, data processing unit 220, and management unit 230 are the same as those in FIG. 6.

[0101] The radio signal processing unit 250A functions as any one of the STA functions assigned to STA1, STA2, and STA3. That is, the radio signal processing unit 250A can exchange traffic on one link (e.g., STA1) among the multiple links constituting the link set LS, and then exchange traffic on other links (e.g., STA2 and STA3) among the multiple links. Note that when transmitting a data frame on one link, the radio signal processing unit 250A cannot transmit the data frame on other links. On the other hand, the radio signal processing unit 250A can receive the above-mentioned management frames in parallel on the multiple links of the link set LS, but may be configured to receive data frames on only one of the multiple links. Note that the multiple links of the link set LS may be assigned different frequency bands, or different channels of the same frequency band.

[0102] Such an operation mode of the radio signal processing unit 250A is also called an EMLSR (Enhanced Multi Link Single Radio) mode.

[0103] When a data frame is input from the data processing unit 220, the MAC frame processing unit 240 determines whether the frame size of the data frame is equal to or greater than a threshold value α. If the frame size is equal to or greater than the threshold value α, the MAC frame processing unit 240 fragments the data frame to generate multiple data frames, each with a frame size less than the threshold value α. The MAC frame processing unit 240 then associates the generated multiple data frames with multiple, mutually different links. The MAC frame processing unit 240 then sequentially inputs the multiple data frames to the radio signal processing unit 250A, for example, in ascending order of fragment number FN. The radio signal processing unit 250A can consider the order of the input data frames to be the transmission order.

[0104] 2.3 Functional configuration for cascade transmission processing Fig. 12 is a block diagram showing an example of a functional configuration related to cascade transmission processing of a radio signal processing unit according to the second embodiment, which corresponds to Fig. 7 in the first embodiment.

[0105] Radio signal processing unit 250A includes a classification unit 251, a plurality of queues 252A, 252B, 252C, and 252D, a plurality of carrier sense units 253A, 253B, 253C, and 253D, and an internal collision management unit 254. The configurations of classification unit 251, a plurality of queues 252A, 252B, 252C, and 252D, and internal collision management unit 254 are the same as those in FIG.

[0106] The carrier sense unit 253 selects a link corresponding to the data frame by referring to the TID in the data frame of transmission order k. Then, the carrier sense unit 253 determines the execution timing of carrier sense processing for the selected link.

[0107] Specifically, when the transmission order k is "1", the carrier sense unit 253 immediately executes the carrier sense process, and then calculates the TXOP end time γ1 of the data frame.

[0108] If the transmission order k is not "1", the carrier sense unit 253 calculates the collision avoidance start time Δk based on the TXOP end time γ(k-1) of the data frame with the transmission order (k-1). The carrier sense unit 253 performs carrier sense processing so that standby processing can be started at the collision avoidance start time Δk. Then, the carrier sense unit 253 calculates the TXOP end time γk of the data frame to be transmitted kth.

[0109] In this way, carrier sense processing in radio signal processing unit 250A is executed sequentially according to transmission order k. Having acquired the transmission right, carrier sense unit 253 extracts a data frame buffered in corresponding queue 252. Having acquired the transmission right, carrier sense unit 253 inputs the extracted data frame to internal collision management unit 254.

[0110] 2.4 Cascade transmission process flowchart 13 is a flowchart showing an example of cascade transmission processing in the transmitting station according to the second embodiment. The cascade transmission processing in the radio signal processing unit 250A operating in the EMLSR mode will be described below with reference to FIG.

[0111] For the sake of convenience, in the following description, it is assumed that the fragmented data frames are stored in queue 252 in the order in which they were transmitted (in ascending order of fragment number FN).

[0112] When a fragmented data frame is buffered in the queue 252 (start), the carrier sense unit 253 initializes the transmission order k to "1" (S21).

[0113] After the process of S21, the carrier sense unit 253 selects a data frame of transmission order k and a corresponding link (S22). That is, after the processes of S21 and S22, the wireless signal processing unit 250A functions as an STA function associated with the link corresponding to the data frame of the first transmission order k (=1).

[0114] After the process of S22, the carrier sense unit 253 determines whether the transmission order k is the first (=1) or not (S23).

[0115] If the transmission order k is the first (S23; yes), the carrier sense unit 253 immediately starts carrier sense processing (S24).

[0116] When the carrier sense process of S24 is performed, the carrier sense unit 253 calculates the TXOP end time γ1 (S25).

[0117] If the transmission order k is not the first (S23; no), the carrier sense unit 253 calculates the collision avoidance start time Δk based on the TXOP end time γ(k−1) (S26).

[0118] The carrier sense unit 253 starts carrier sense processing so as to match the collision avoidance start time Δk calculated in the processing of S26 (S27).

[0119] When the carrier sense process of S27 is executed, the carrier sense unit 253 calculates the TXOP end time γk (S28).

[0120] The carrier sense unit 253 determines whether or not the transmission right has been acquired through the carrier sense process of S24 or S27 (S29).

[0121] If the transmission right is acquired (S29; yes), the carrier sense unit 253 determines whether the transmission order k is the first or whether the current time has passed the TXOP end time γ(k−1) (S30).

[0122] If the transmission order k is not the first and the current time has not passed the TXOP end time γ(k-1) (S30; no), the carrier sense unit 253 waits until the DIFS period has passed from the TXOP end time γ(k-1) (S31).

[0123] After the process of S31, or if the transmission order k is the first or the current time has passed the TXOP end time γ(k−1) (S30; yes), the radio signal processing unit 250A starts the transmission process (S32).

[0124] If the transmission right cannot be acquired (S29; no), the radio signal processing unit 250A postpones the transmission process (S33).

[0125] After the process of S32 or S33, the carrier sense unit 253 detects that the kth transmission is the last (=k M ) (S34).

[0126] If the transmission order k is not the last (S34; no), the carrier sense unit 253 increments the transmission order k (S35).

[0127] Then, the carrier sense unit 253 selects the data frame with the transmission order k incremented in the process of S35 and the corresponding link (S22). That is, after the process of S35, the wireless signal processing unit 250A functions as an STA function associated with the link corresponding to the data frame with the next transmission order. After the process of S22, the subsequent processes of S23 to S34 are executed. In this way, the processes of S22 to S35 are executed while incrementing the transmission order in the process of S35 until the transmission order k becomes the last.

[0128] If the transmission order k is the last (S34; yes), the cascade transmission process in the radio signal processing unit 250A ends (end).

[0129] 2.5 Cascade Send Processing Example Fig. 14 is a timing chart showing an example of cascade transmission processing in a transmitting station according to the first embodiment. Fig. 14 corresponds to Fig. 9 in the first embodiment. Fig. 14 shows a case where the STA functions in EMLSR mode corresponding to STA1, STA2, and STA3 transmit a data frame first, second, and third, respectively. Hereinafter, the STA functions in EMLSR mode corresponding to STA1, STA2, and STA3 will be simply referred to as "STA1," "STA2," and "STA3," respectively.

[0130] The wireless signal processor 250A selects STA1 based on the TID of the data frame to be transmitted first. STA1 promptly performs carrier sensing on the data frame to be transmitted first. STA1 then calculates the TXOP end time γ1 during the carrier sensing process. After that, when STA1 acquires the right to transmit through the carrier sensing process, it starts transmission processing.

[0131] Next, the wireless signal processor 250A selects STA2 based on the TID of the second-to-be-transmitted data frame. STA2 calculates the collision avoidance start time δ2 based on the TXOP end time γ1, and starts carrier sensing so that it coincides with the collision avoidance start time δ2. This allows STA2 to start waiting processing at least by the TXOP end time γ1. STA2 also calculates the TXOP end time γ2 during carrier sensing.

[0132] When STA2 acquires the transmission right through carrier sense processing, it determines whether the current time has passed the TXOP end time γ1. In the example of FIG. 14, the TXOP end time γ1 has not passed when STA2 acquires the transmission right. In this case, STA2 waits until the DIFS period has passed since the TXOP end time γ1 to reconfirm that no collision will occur. Then, when it is confirmed that no collision will occur, STA2 starts transmission processing.

[0133] Next, the wireless signal processor 250A selects STA3 based on the TID of the third transmitted data frame. STA3 calculates the collision avoidance start time δ3 based on the TXOP end time γ2, and starts carrier sense processing so as to match the collision avoidance start time δ3. This allows STA3 to start at least standby processing by the TXOP end time γ2.

[0134] When STA3 acquires the transmission right through carrier sense processing, it determines whether the current time has passed the TXOP end time γ2. In the example of Figure 14, the TXOP end time γ2 has passed when STA3 acquires the transmission right. In this case, STA3 immediately starts transmission processing.

[0135] When the transmission process by STA3 is completed, the cascade transmission process is completed.

[0136] 2.6 Effects of the Second Embodiment According to the second embodiment, when operating in EMLSR mode, the STA function with transmission order k starts carrier sensing while the STA function with transmission order (k-1) is exchanging traffic. More specifically, the STA function with transmission order k starts carrier sensing so that it can start collision avoidance processing earlier than the TXOP end time γ(k-1) by the sum of the average values ​​of DIFS and backoff. The STA function with transmission order k that has acquired the transmission right starts traffic exchange following the traffic exchange of the STA function with transmission order (k-1). This increases the likelihood that the STA function with transmission order k will acquire the transmission right after the traffic exchange of the STA function with transmission order (k-1) ends. This shortens the gap between traffic exchanges on different links, thereby suppressing degradation of delay characteristics. Furthermore, using multiple links allows large volumes of data to be distributed across multiple links. This prevents a specific link from being occupied for a long period of time.

[0137] Furthermore, if a STA function acquires a transmission right before the TXOP end time γ(k-1), the STA function of transmission order k waits until the DIFS period has elapsed since the TXOP end time γ(k-1) before starting transmission processing. This allows the STA function of transmission order k to check again at the TXOP end time γ(k-1) whether a collision with other traffic will occur on the link where the STA function acquired the transmission right. This makes it possible to more reliably avoid collisions.

[0138] Furthermore, if a transmission right is acquired after the TXOP end time γ(k-1), the STA function of transmission order k immediately starts transmission processing without additional waiting. This shortens the gap between traffic exchanges on different links. Therefore, the degradation of delay characteristics can be suppressed.

[0139] 3. Modifications, etc. It should be noted that the above-described first and second embodiments can be modified in various ways.

[0140] For example, in the second embodiment described above, the case where the wireless signal processor 250A in EMLSR mode can execute back-off standby processing on one link while executing transmission processing on another link has been described, but this is not limiting. For example, the wireless signal processor 250A in EMLSR mode may not be able to execute back-off standby processing on one link while executing transmission processing on another link.

[0141] Fig. 15 is a timing chart showing an example of cascade transmission processing by a transmitting station according to a modified example, and corresponds to Fig. 14 in the second embodiment.

[0142] The carrier sense unit 253 can calculate the collision avoidance start time δ'k based on the TXOP end time γ(k-1). The collision avoidance start time δ'k is set to be, for example, a DIFS period earlier than the TXOP end time γ(k-1). Then, the carrier sense unit 253 performs carrier sense processing so that standby processing can be started at the collision avoidance start time δ'k.

[0143] By operating in this manner, it is possible to avoid the overlapping execution of backoff waiting processes on other links while transmission processing is being performed on one link. Even in this case, carrier sense processing for the (k+1)th data frame can be performed in advance on other links before the end of transmission processing for the kth data frame. This increases the possibility of obtaining the transmission right for the (k+1)th data frame and suppresses deterioration of delay characteristics.

[0144] Furthermore, for example, in the above-described first and second embodiments, the cascade transmission process is applied to a plurality of data frames generated by fragmentation processing, but this is not limiting. For example, the cascade transmission process may be applied to a plurality of data frames generated by aggregation processing.

[0145] More specifically, for example, when performing aggregation processing on multiple MSDUs (MAC Service Data Units) or MPDUs (MAC Protocol Data Units), the frame size of the aggregated data frame is restricted to be less than a threshold value β. The threshold value β is a positive real number. This allows the MAC frame processing units 140 and 240 to divide a single large-capacity data frame into multiple data frames, each with a frame size less than the threshold value β. By transmitting multiple data frames with a size less than the threshold value β through cascade transmission processing, the period during which a specific link is occupied can be made shorter than when transmitting a single large-capacity data frame. Therefore, the same effects as those of the first and second embodiments can be achieved.

[0146] The data frames generated by the aggregation process include a sequence number SN, which allows the STA function to extract the transmission order k of the input data frame by further referring to the sequence number SN.

[0147] The cascade transmission process according to the first and second embodiments described above can also be stored as a program that can be executed by a processor, which is a computer. Alternatively, the program can be stored and distributed in a storage medium of an external storage device, such as a magnetic disk, optical disk, or semiconductor memory. The processor can then load the program stored in the storage medium of the external storage device, and its operation can be controlled by the loaded program, thereby executing the cascade transmission process.

[0148] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention. [Explanation of symbols]

[0149] 1. Communication systems 10...Access point 20...Terminal 30…Network 11,21...CPU 12,22…ROM 13,23…RAM 14,24...Wireless communication module 15...Wired communication module 25…Display 26…Storage 200...Application execution unit 110,210...LLC Processing Section 120, 220...Data processing section 130,230…Management Department 131,231...Link management information 132,232...Link Management Department 140, 240...MAC frame processing section 150, 160, 170, 250, 250A, 260, 270...Wireless signal processing unit 251...Classification section 252...Queue 253…Career Sense Department 254…Internal conflict management department

Claims

[Claim 1] A transmitting station that transmits to a receiving station in accordance with the IEEE 802.11 standard, First transmission unit, A management unit establishes a multilink, including a first link and a second link, with the receiving station using the first transmitting unit, Equipped with, The first transmitting unit is, Of the multiple fragments generated by fragmenting a single transmission data, the fragment assigned to the first link is transmitted via the first link, and then the fragment assigned to the second link is transmitted via the second link. It is configured in such a way. Transmitting station.

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