Communication device, control method, and program

Abstract

Provided is a communication device capable of wireless communication on the basis of the IEEE 802.11 standard, the communication device being capable of transmitting, to an access point connected to the communication device, a frame containing information related to preemption involving low-latency data. Further, the communication apparatus transmits data to the outside in accordance with receiving a trigger frame issued after the frame is transmitted to the access point.

Description

Technical Field

[0001] This invention relates to a communication device for wireless communication. Background Technology

[0002] The Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard is known as the communication standard associated with wireless local area networks (wireless LANs). In the IEEE 802.11be standard and its successors, the coordinated operation of multiple access point devices (hereinafter referred to as APs) is considered to increase communication efficiency and throughput.

[0003] Patent document 1 discloses a feature known as Restricted Target Wake-up Time (R-TWT), which involves establishing a time period that can be used to communicate data that requires low latency, and transmitting the data that requires low latency during that time period.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: US Patent Publication No. 2022 / 0070772 Summary of the Invention

[0007] Technical issues

[0008] The aforementioned feature, known as R-TWT, can be implemented to reduce latency in cases where data is transmitted regularly during the scheduled time period.

[0009] On the other hand, in other cases, data requiring low latency may occur outside the aforementioned scheduled time period. In order to transmit this data with low latency, it is necessary to use features different from RTWT to achieve priority transmission.

[0010] The present invention has been designed to address at least one of the above problems. In one aspect of the invention, an object is to provide a mechanism in which, during communication of a wireless frame containing specific data, different data is transmitted instead of the specific data.

[0011] Solution for solving the problem

[0012] A communication device according to one aspect of the invention is characterized by including a first transmission control unit that, when receiving data transmitted from the access point to the communication device during a transmission opportunity obtained using an access point connected to the communication device, and data to be transmitted with low latency and to the outside is stored in the transmission queue of the communication device, transmits a frame containing information indicating acknowledgment of the received data and information relating to preemption of the low-latency data.

[0013] Advantages of the invention

[0014] According to one aspect of the invention, during communication of a wireless frame containing specific data, different data may be transmitted instead of the specific data. Attached Figure Description

[0015] [ Figure 1 ] Figure 1 This is a diagram showing an example of network configuration.

[0016] [ Figure 2 ] Figure 2 This is a diagram showing the hardware configuration of the communication device.

[0017] [ Figure 3 ] Figure 3 This is a diagram showing the software configuration of the communication device.

[0018] [ Figure 4 ] Figure 4 This is a diagram showing an example of a wireless frame.

[0019] [ Figure 5 ] Figure 5 This is a diagram showing an example of a trigger frame.

[0020] [ Figure 6 ] Figure 6 This is a diagram used to illustrate preemptive control.

[0021] [ Figure 7 ] Figure 7 This is a diagram used to illustrate different preemption control methods.

[0022] [ Figure 8 ] Figure 8 This is an example of control performed by STA.

[0023] [ Figure 9 ] Figure 9 This is an example of control performed by the AP.

[0024] [ Figure 10 ] Figure 10 This is an example of receive control performed by the AP.

[0025] [ Figure 11 ] Figure 11 This is an example of transmission control performed by the STA.

[0026] [ Figure 12A [] is a schematic diagram used to illustrate the variation.

[0027] [ Figure 12B [] is a schematic diagram used to illustrate the variation. Detailed Implementation

[0028] The embodiments are described in detail below with reference to the accompanying drawings. However, the following embodiments do not limit the invention as described in the claims. Although multiple features are described in the embodiments, not all features are necessarily essential to the invention, and multiple embodiments can be combined in any way. Furthermore, in the drawings, the same or similar configurations are indicated by the same reference numerals, and repeated descriptions are omitted.

[0029] <Configuration of the Communication System>

[0030] Figure 1 An example configuration of a wireless communication system according to this embodiment is shown. This wireless communication system includes one access point device (hereinafter also referred to as AP, AP STA, or access point) and two station devices (hereinafter also referred to as STA, non-AP STA, or station). Hereinafter, AP 101 and STA 103-1 to 103-n are collectively referred to as communication devices.

[0031] AP 101 is configured to perform communication using wireless frames compliant with the IEEE 802.11bn standard, which is the successor to the IEEE 802.11be standard, targeting a maximum transmission rate of 46.08 Gbps. STAs 103-1 to 103-n are similarly configured to perform communication using wireless frames compliant with the successor standard.

[0032] Note that IEEE is the abbreviation for the Institute of Electrical and Electronics Engineers. The main features of 802.11bn, the successor to 802.11be, are high-reliability communication, low-latency communication, and improved throughput under congestion. Radio frames used in communication under the successor standard are also called Ultra-High Reliability (UHR) PPDUs. PPDU is an abbreviation for Protocol Data Unit (PLCP), and PLCP is an abbreviation for Physical Layer Convergence Protocol.

[0033] Note that, for convenience, the names of the IEEE 802.11bn and UHR standards have been established based on the goals to be achieved in subsequent standards and the features that will be the main focus of the standards, and can be referred to by different names once the standards are completed. On the other hand, it should be understood that this specification and the appended claims are essentially successors to the 802.11be standard and apply to all subsequent standards.

[0034] Note that, although Figure 1A wireless communication network consisting of one AP and n STAs is shown as an example, but the number of devices may be more or less than shown. It is assumed that AP 101 and STAs 103-1 to 103-n support communication (transmission and reception) of UHR PPDUs under the 802.11bn standard, but this is not a limitation. In addition to the above, the communication devices can also be configured to support communication of PPDUs under legacy standards (i.e., standards prior to 802.11bn). Specifically, AP 101 and STAs 103-1 to 103-n can be configured to support the transmission and reception of PPDUs under standards such as IEEE 802.11a / b / g / n / ac / ax / be, etc.

[0035] AP 101 provides network access to STAs. STAs 103-1 to 103-n join the network provided by AP 101. Figure 1 This shows an example of a scenario where STAs 103-1 to 103-n have joined the network provided by AP 101.

[0036] Note that AP 101 and STA 103-1 to 103-n can also be configured to support another communication standard (such as Bluetooth). ® NFC or Bluetooth ® Low Energy (Bluetooth) ® Wireless communication using technologies such as Low Energy (LE) and Near Field Communication (NFC).

[0037] AP 101 can also be configured to support Ethernet. ® Wired communication via cable and / or wired communication using fiber optic cable. This embodiment assumes AP 101 is connected via Ethernet. ® The case involves a cable connection to the Internet. Specific examples of AP 101 and STA 103-1 to 103-n include, but are not limited to, wireless LAN routers and personal computers (PCs). AP 101 and 103-1 to 103-n can also be information processing devices that support the transmission and reception of UHR PPDUs, such as wireless chips. Specific examples of 103-1 to 103-n include, but are not limited to, cameras, tablets, smartphones, PCs, mobile phones, camcorders, projectors, and wearable devices such as smart glasses.

[0038] Each communication device (such as AP 101 and STA 103-1 to 103-n) can communicate using bandwidths of 20MHz, 40MHz, 80MHz, 160MHz, 320MHz, 480MHz or 640MHz.

[0039] Incidentally, in recent years, the demand for low-latency communication in wireless communications has also been increasing. For example, to meet this demand, the 802.11be standard provides a feature called Restricted Target Wake-Up Time (R-TWT), which involves establishing time periods that can be used for communication requiring low latency. The R-TWT feature can be implemented to reduce latency when transmitting data that occurs regularly during the scheduled time period. On the other hand, in other cases, the data requiring low latency may occur outside the aforementioned scheduled time period. To transmit this data with low latency, it is necessary to use features different from R-TWT to prioritize low-latency transmission.

[0040] To prioritize the transmission of irregularly occurring data requiring low-latency communication, this embodiment provides a mechanism in which low-latency data can be transmitted instead of the specific data during the transmission of a radio frame used for communicating that specific data. The details are described below.

[0041] (Device Configuration)

[0042] Figure 2 An example of the hardware configuration of a communication device (AP and STA) is shown. The communication device includes a storage unit 201, a control unit 202, a functional unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207, as an example of the hardware configuration of the communication device. Note that in this embodiment, it is assumed that the communication device has multiple antennas, but a single antenna may also be present.

[0043] Storage unit 201 is formed by one or both of ROM and RAM, and stores various information, such as programs for performing various operations described later and communication parameters for wireless communication. RAM is an abbreviation for Random Access Memory, and ROM is an abbreviation for Read-Only Memory. Note that in addition to memories such as ROM and RAM, storage unit 201 may also use storage media such as hard disks, solid-state drives (SSDs), or other non-volatile storage devices.

[0044] The control unit 202 is configured, for example, by a processor such as a CPU or MPU, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), or a field-programmable gate array (FPGA). CPU is an abbreviation for Central Processing Unit, and MPU is an abbreviation for Microprocessor Unit. The control unit 202 controls the device overall by executing programs stored in storage unit 201 and also by operating the ASIC or other hardware circuitry. Note that the control unit 202 can also control the device overall through cooperation between the programs stored in storage unit 201 and an operating system (OS).

[0045] Control unit 202 also controls functional unit 203 to perform prescribed processes such as imaging, printing, and projection. Functional unit 203 is the hardware used by the device to perform the prescribed processes. For example, in the case where the communication device is a camera such as a digital still camera or a smartphone equipped with a camera, functional unit 203 is an imaging unit and performs imaging processing of surrounding images via a camera unit (not shown) included in the communication device. As another example, in the case where the communication device is a printer, functional unit 203 is a printing unit and performs processing to print on a sheet such as paper based on printing data obtained from the outside via wireless communication. As another example, in the case where the communication device is a projector or smart glasses, functional unit 203 is a projection unit and performs processing for projecting image data and / or video data obtained from the outside via wireless communication. In the case of smart glasses, the projection surface is the end user's retina, etc. The data to be processed by functional unit 203 may be data stored in storage unit 201 or data communicated with another AP or STA via communication unit 206, which will be described later.

[0046] Input unit 204 accepts various operations from the user. Output unit 205 provides various outputs to the user. In this context, the outputs provided by output unit 205 include at least one of the following: visual presentation on the screen, sound output from the speaker, and vibration output. Note that input unit 204 and output unit 205 can also be implemented as a single module, such as a touch panel.

[0047] Communication unit 206 controls wireless communication conforming to the IEEE 802.11 series of standards and controls IP communication. In this embodiment, communication unit 206 can cooperate with antenna 207 to perform the transmission and reception of UHR PPDU (i.e., UHR standard radio frames) and / or PPDUs corresponding to previous standards. Antenna 207 can transmit and receive signals in at least one of the following frequency bands: sub-GHz band, 2.4GHz band, 5GHz band, 6GHz band, 7GHz band, and 60GHz band.

[0048] Note that the communication device must support the aforementioned NFC standards and / or Bluetooth. ® In the case of standards, the communication unit 206 can be configured to control wireless communication conforming to these communication standards.

[0049] Next, we will use Figure 3 Describe the functional configuration of the communication devices (AP 101 and STA 103-1 to 103-n). Figure 3 It is a block diagram used to illustrate the functional configuration of a communication device.

[0050] The communication device includes a wireless LAN control unit 301, a frame generation unit 302, a frame processing unit 303, a settings management unit 305, and a UI control unit 304.

[0051] The functions are described below. The wireless LAN control unit 301 controls the antenna 207 and the communication unit 206 to transmit and receive wireless signals relative to another communication device. Specifically, the wireless LAN control unit 301 cooperates with the frame generation unit 302 and the frame processing unit 303 to perform communication control of wireless frames such as UHR PPDUs according to the IEEE 802.11 series standards.

[0052] The frame generation unit 302 generates a wireless frame to be transmitted by controlling the communication unit and antenna based on instructions from the wireless LAN control unit 301. The wireless frame consists of a preamble field and a data field. The data field stores MAC frames such as management frames, control frames, and data frames. The wireless LAN control unit 301 manages multiple transmission queues (not shown) that have been assigned relative priorities, and instructs the frame generation unit 302 to generate wireless frames based on data accumulation conditions in the multiple transmission queues.

[0053] The generated wireless frames, containing physical layer (PHY) preambles and data, are transmitted to the outside by the wireless LAN control unit 301, communication unit 206, and antenna 207. Furthermore, data from wireless frames received through the cooperation of antenna 207, communication unit 206, and wireless LAN control unit 301 is passed to frame processing unit 303. Frame processing unit 303 analyzes the data in the wireless frames and notifies functions in higher layers (not shown), or performs processing for controlling wireless communication based on the information obtained through analysis. For example, if the communication device is an AP and the data addressed to STA 103-1 is stored in wireless frames received from the outside, the data can be stored in one of the aforementioned transmission queues based on the data type.

[0054] The management unit 305 manages the communication parameters required for network construction and STA communication, such as the MCS used for communication with other communication devices, the operating frequency band of the communication device itself, the BSS ID, the BSS color, and information about the bandwidth used for communication PPDUs. MCS is an abbreviation for Modulation and Coding Scheme and indicates the modulation and coding scheme to be applied to communication. BSS ID is an abbreviation for Basic Service Set Identifier and uniquely identifies the network. The BSS color is a value corresponding to the color code used for BSS determination. The BSS color is set to a value that does not overlap with another nearby AP. In addition to the above, various information for preemption control, etc., is also stored.

[0055] The UI control unit 304 collaborates with the output unit 205 to provide an operation screen to the user, and with the input unit 204 to detect user operations (such as modifications to operation settings made on the aforementioned operation screen), and requests the setting management unit 305 to apply the modifications to the operation settings. The UI control unit 304 collaborates with the output unit 205 to provide the user with a modification screen for modifying operation settings regarding whether to transmit a preemptible PPDU. If a user operation to modify operation settings is detected on the modification screen, the setting management unit 305 is requested to apply the modifications to the operation settings. Upon receiving the request, the setting management unit 305 modifies the stored operation settings.

[0056] Next, we will use Figure 4 Describe the UHR PPDU that the communication device in this embodiment will transmit. Figure 4 An example of the format of a UHR multi-user (MU) PPDU to be transmitted by a communication device is shown.

[0057] Figure 4 The UHR PPDU shown includes a Short Training Field (STF), a Long Training Field (LTF), and a Signal Field (SIG). For example... Figure 4 As shown, the beginning of the PPDU contains fields 401 to 403 to ensure backward compatibility with the IEEE 802.11a / b / g / n / ax standards.

[0058] Specifically, it includes a traditional short training field (L-STF) 401 and a traditional long training field (L-LTF) 402 as training fields. In addition, it includes a traditional signal field (L-SIG) 403 as a signal field.

[0059] Note that L-STF is placed immediately after L-LTF, and L-SIG is placed immediately after L-LTF. Furthermore, a duplicate L-SIG (RL-SIG) is placed immediately after L-SIG. The content of L-SIG is repeated and transmitted within the RL-SIG field. RL-SIG allows the receiver to identify that the PPDU conforms to IEEE 802.11ax and later standards.

[0060] L-STF is used for PHY frame signal detection, automatic gain control (AGC), and timing detection. L-LTF is used for precise frequency / time synchronization and channel state information (CSI) acquisition. L-SIG is used to transmit control information, including information related to the data transmission rate and PHY frame length. A communication device receiving a radio frame can use this information to determine the timing at which the radio frame transmission will be completed. Devices compliant with IEEE 802.11a / b / g / n / ax standards and those compliant with 802.11be standards or UHR successors can decode these various legacy fields.

[0061] The PPDU also includes a General Signal Field (U-SIG) 405 placed immediately after RL-SIG. U-SIG is planned to be used in IEEE 802.11be and later standards and is the field used to transmit control information for each standard. U-SIG includes a PHY version identifier field storing the PHY version and a BSS color field storing the color code used for BSS determination. In the case of a UHR MU PPDU, the value indicating the UHR MU PPDU (e.g., 1) is stored in the PHY version identifier.

[0062] The Ultra-High Reliability Signal Field (UHR-SIG) 406 is placed immediately after U-SIG. UHR-SIG includes control information that cannot be adapted to U-SIG and control information that needs to be reported to each user in the case of multi-user transmission.

[0063] Next, following UHR-SIG 406, UHR-STF 407, serving as an STF for UHR, and UHR-LTF 408, serving as an LTF for UHR, are placed. The UHR-LTF contains information to be used for MIMO estimation and beamforming estimation, etc. Multiple UHR-LTFs can be placed depending on the number of MIMO antennas and whether beamforming is required. Up to eight UHR-LTFs can be placed.

[0064] Following these control fields, place data field 409 and package extension field 410. Figure 4 The fields from L-STF to UHR-LTF in the PPDU are called PHY preambles.

[0065] Next, we will use Figure 5 This describes the Media Access Control (MAC) frame stored in data field 409. Figure 5 The format of the trigger frames transmitted by AP 101 to surrounding STAs is shown. Figure 5The trigger frame shown is a control frame used by the AP to send an instruction to the lower-level STA to initiate uplink communication. The STA designated as the destination in the trigger frame can transmit uplink data in response to the receipt of the trigger frame.

[0066] Fields 501 to 505 conform to the content of a MAC frame according to the IEEE 802.11 standard, and therefore descriptions are appropriately omitted. In field 501, "01" is stored in the type value subfield (B3-B2), and "0010" is stored in the subtype value subfield (B7-B4) to indicate that the frame is a trigger frame. Furthermore, this embodiment assumes that "0" indicating Basic is stored in the trigger type subfield of field 505. However, this configuration is not limited to the above. When a trigger frame is issued for low-latency communication as described later, the trigger frame can also be configured to store other values ​​to indicate that the frame is a trigger frame for transmitting low-latency data. In this case, for example, one of the values ​​from 8 to 15 currently in a reserved state is defined as indicating a trigger frame for low-latency communication. Then, when a trigger frame for low-latency communication is issued, AP 101 can be configured to store the defined value in the trigger type subfield of field 505.

[0067] Next, user information list field 506 will be described. Field 506 stores one or more user information fields that combine information identifying one or more STAs to perform uplink communication and information such as transmission conditions to be transmitted to that STA. When multiple STAs are transmitting uplink data simultaneously, AP 101 stores multiple user information fields in field 506. For example, if STA 103-1 and STA 103-2 are to perform uplink communication, AP 101 stores two user information fields in field 506.

[0068] In this embodiment, it is assumed that AP 101 includes a user information field in a UHR variant format that can be interpreted by a communication device that supports the IEEE 802.11bn standard.

[0069] This field includes an AID12 subfield 509 that stores information identifying the STA to perform uplink communication, and an RU allocation subfield 510 that indicates the resource unit (RU) to be used by the STA. This field also includes a UL UHR-MCS subfield 512 that indicates the modulation scheme to be used during transmission. Subfields 511 and 513-515 also indicate other transmission conditions. The PS160 field stores information about the large-size MRU. The STA receiving this information identifies the RU it will use for uplink transmission based on the value of the PS160 subfield 516 and the value of the RU allocation subfield 510. Note that values ​​with specific meanings (such as "0" or "2045") can also be stored in the AID12 subfield 509. 0 indicates that the STA connected to AP 101 is a RA-RU capable of using the uplink OFDMA Random Access (UORA) function.

[0070] 2045 indicates that the STA not connected to AP 101 is a RA-RU capable of using the uplink OFDMA random access (UORA) function.

[0071] Finally, the trigger-dependent user information subfield 517 will be described. 517 consists of 518 and 519 storing more detailed transmission conditions, and 520 and 521 storing information indicating transmission-related recommendations. The LL (Low Latency) indication subfield 520 stores 1 bit information indicating whether the frame is a transmission opportunity allocated to the STA for low-latency data transmission. A stored "1" indicates that the frame is a transmission opportunity allocated to the STA for low-latency data transmission, while a stored "0" indicates that the frame is not a regular transmission opportunity limited to low-latency data. Next, the preferred AC subfield 521 stores information indicating the preferred AC (i.e., traffic type) for transmission.

[0072] Specifically, it stores a value corresponding to any one of AC_VO for voice data, AC_VI for video data, AC_BE for best-effort data, and AC_BK for background data.

[0073] Note that while subfield 520 stores a "1", the value stored in subfield 521 can also be assigned different meanings. For example, it can store a value indicating that mission-critical traffic (such as data for autonomous driving, input for robot manipulation, and input for remote control of medical systems) is preferably used for transmission. Furthermore, it can store a value indicating that traffic for entertainment purposes such as online games and XR (extended reality) is preferably used for transmission, for which latency should be as low as possible, even though the traffic has a relatively lower priority than the values ​​mentioned above. Additionally, it can store values ​​indicating that other low-latency traffic, even with lower priority, can be transmitted.

[0074] Next, we will use Figure 6 Describe the preemptive communication in this embodiment. Figure 6 This is a schematic diagram illustrating the preemptive communication in this embodiment.

[0075] Figure 6 This diagram illustrates a method by which one of the STAs 103 preemptively transmits a low-latency frame in the uplink transmission while AP 101 has acquired a TXOP and is transmitting data downlink from AP 101 to the STA 103-1. Initially, AP 101 can transmit data downlink until the acquired TXOP period is used up. In the first preemptive communication control according to this embodiment, preemptive communication of low-latency data is achieved by utilizing the TXOP that AP 101 has secured for the downlink. Specifically, based on information from the STA regarding the expected occurrence of low-latency data and information indicating that low-latency data has actually occurred, a trigger frame for the uplink is appropriately issued, and uplink transmission is performed. The following is a detailed description.

[0076] First, AP 101 receives frames from the STA in advance and obtains information indicating that the STA "may preemptively transmit low-latency frames" (601-1). Due to space constraints, in Figure 6 In other diagrams and the following description, the uplink PPDU containing the above information is referred to as a UL PPDU (with PO), and the information itself is referred to as PO information. PO is an abbreviation for preemption occurrence. It is also possible to configure the system to report the expected hypothetical data volume in the event of low-latency data along with the above information. In this case, AP 101 uses the pre-acquired hypothetical data volume to determine the size of the RU to be allocated to the STA.

[0077] In this scenario, it is assumed that information is included, instructing STA 103-1 and STA 103-n to potentially preemptively transmit low-latency frames. This information can be obtained when AP 101 establishes a connection with STA 103-1 and STA 103-n, or at any time thereafter. An expiration period can also be established, and the information can be updated before the expiration period expires.

[0078] Next, the processing during downlink transmission from AP 101 to STA will be described. AP 101 acquires a TXOP and begins data transmission to the STA. Specifically, it exchanges Request to Send (RTS) frames, Clear to Send (CTS) frames, data frames, and Block Ack (Acknowledgement) (BA) frames with the STA. This example illustrates the case of downlink communication to STA 103-1. Furthermore, it is assumed that even after receiving the BA as an acknowledgment, subsequent downlink data to be transmitted to STA 103-1 accumulates in the transmission queue.

[0079] Furthermore, in this embodiment, the STA (e.g., STA 103-1) receiving data from the AP on the downlink can transmit both the BA (Balanced Frame) and Immediate Preemption (PI) information indicating the presence of preemptive data. This information can be configured to be extended into a BA frame and stored in a region of the BA frame, or it can be implemented by transmitting a BA frame coupled to a MAC frame containing the PI information. Another possible configuration is to transmit the PI information via the HT control field and / or QoS field of the extended MAC frame. The following description of this embodiment provides an example of transmitting PI information via the HT control field. Another possible configuration is to include the PI information along with information indicating the amount and / or type of low-latency data that the STA expects to transmit.

[0080] At this point, AP 101, having already received the PO information in 601-1 and / or the PI information in 602, temporarily interrupts transmission processing, even if data to be transmitted to STA 103-1 accumulates in the transmission queue. Then, the AP transmits trigger frame 603 to accept low-latency data from the STA on the uplink. In this case, AP 101 appropriately determines transmission conditions based on the PO information and assumed data volume, or the PI information and the amount and type of data, such as which RU is assigned to which STA in the trigger frame, how many RA-RUs are provided, and the uplink transmission period. Figure 5 The trigger frame shown in the example is transmitted externally, enabling uplink transmission based on the determined information. For illustrative purposes, the following description assumes that AP 101 transmits a trigger frame to allocate RUs to STA 103-1 and STA 103-n.

[0081] If the STA receiving trigger frame 603 is designated as being allowed preemptive uplink transmission and has preemptive data, then the STA transmits a UL TB PPDU to AP 101. AP 101 receiving the UL TB PPDU transmits a multi-STA BA. Note that although omitted due to space constraints, preemptive data can also be transmitted using an RA-RU that has already won the transmission opportunity by decreasing the OBO counter, if an RA-RU is specified in the trigger frame. Note that if no PI or PO information is received from any STA, AP 101 can simply transmit downlink data to STA 103-1, etc., without issuing such a trigger frame. Note that details such as the timing of issuing the trigger frame will be described later.

[0082] After that, if the TXOP time is still remaining, AP 101 will again conduct regular TXOP-compatible downlink communication with STAs (such as STA 103-1, etc.).

[0083] Will use Figure 7 To describe the different preemptive communication methods in this embodiment. Figure 7 This is a schematic diagram illustrating the different preemptive communication methods in this embodiment.

[0084] Figure 7 This is a schematic diagram illustrating the process of preemptive control for low-latency data when STA 103-1 has acquired the TXOP and data is being transmitted downlink from AP 101 to STA 103-1. Similar to... Figure 6 The steps in the process are represented by similar notation.

[0085] As indicated in 601-1, AP 101 receives PO information from STA in advance. AP 101 can be configured to... Figure 6 The process involves receiving PO information and the assumed data volume together.

[0086] Subsequently, STA 103-1 acquires the TXOP and exchanges RTS frames, CTS frames, data frames, and BA frames between STA 103-1 and AP 101. The difference lies in the data sender / receiver relationship. Figure 6 on the contrary.

[0087] When AP 101 determines, based on PO information and assumed data volume, that low-latency data should be accepted on the uplink under such circumstances, it includes PI information in the BA frame transmitted to STA 103-1 for transmission (701). STA 103-1, which receives both the BA frame and PI information, recognizes that the expected uplink transmission has been preempted by low-latency data and will therefore be interrupted, and thus interrupts the transmission process.

[0088] Then, the AP transmits trigger frame 702 to accept low-latency data on the uplink. At this point, the determination of transmission conditions, etc., can be similar to that using... Figure 6 The method described is implemented in this way. Note that since this transmission occurs because STA 103-1 has given up its transmission opportunity, a configuration that prioritizes STA 103-1 can also be used. Specifically, if there are excess RUs remaining that can be used for uplink transmission but have already been allocated to each STA for receiving hypothetical low-latency data, AP 101 can be configured to allocate RUs with a larger number of subcarriers (tones) to STA 103-1.

[0089] For illustrative purposes, the following description provides an example of a scenario where RUs for uplink transmissions are assigned to STA 103-1 and STA 103-n.

[0090] If the STA receiving trigger frame 702 is itself designated as permitted for preemptive uplink transmission and the STA has preemptive data, then the STA transmits a UL TB PPDU to AP 101. AP 101 receiving the UL TB PPDU transmits a multi-STA BA.

[0091] Upon receiving a multi-STA BA, STA 103-1 resumes uplink transmission processing if it determines that its guaranteed TXOP is still available. For example, it performs regular TXOP-compatible communication with AP 101.

[0092] The different preemption processes described above can also be used to achieve preemptive uplink transmission when another STA is carrying out uplink transmission.

[0093] Next, we will use Figures 8 to 11 The flowchart in the diagram is used to describe the specific control. Figure 8 and Figure 11 This is a flowchart illustrating an example of PPDU communication control performed by a communication device that is any one of STA 103-1 to 103-N. Figure 9 and Figure 10 This is a flowchart illustrating an example of PPDU communication control performed by a communication device as AP 101. Figures 8 to 11 The flowchart in the document illustrates a series of excerpted steps for implementing preemptive control.

[0094] Execution is achieved by having the processor in the control unit 202 of each STA 103 execute the computer program stored in the storage unit 201. Figure 8 and Figure 11The various processing steps are shown in the flowchart. They are executed by causing the processor in the control unit 202 of AP 101 to execute the computer program stored in the storage unit 201. Figure 9 and Figure 10 The flowchart illustrates the various processing steps. Note that it is assumed that some processing steps, such as those described above, are implemented by having the processor in the control unit 202 of each communication device work in conjunction with the communication unit 206 and the ASIC, DSP, and / or FPGA in the control unit 202. Figures 8 to 11 This includes transmission, modulation, reception, and / or decoding. Note that the use of [specific terminology] is necessary when it is important to clearly indicate the entity responsible for the processing steps. Figure 3 One of the functional units described is used as the grammatical subject of the description.

[0095] First, we will use Figure 8The communication control of STAs 103-1 to 103-N is described below. In S800, frame generation unit 302 generates a UL PPDU containing information indicating whether preemption is possible. Then, wireless LAN control unit 301 cooperates with communication unit 206 to transmit the UL PPDU containing information indicating whether preemption is possible to the AP to which the STA is connected (e.g., AP 101). The processing in S800 corresponds to the transmission of a UL PPDU containing PO information, as illustrated by example in S601-1. Note that this information can be included in the HT control field located at the end of the MAC header. More specifically, the PO information can be notified to the AP by storing it in the A control field of the HE variant format HT field with B0-B1 set to "11". For example, each STA stores a UHR operating mode (UHR OM) field in the A control field of the HT control field. Specifically, the UHR OM is included in a control subfield, which consists of a control ID corresponding to the UHR OM field and a corresponding control information subfield. As an example, "0x10" can be specified in the control ID corresponding to the UHR OM. Then, each STA stores the PO information in the control information subfield. If preemption is deemed possible, each STA sets "1" in the area storing the PO information; if preemption is deemed unlikely, each STA sets "0" in the area storing the PO information. This mechanism can be used to inform the AP whether preemption is possible. Note that the method for transmitting PO information is not limited to the above. Furthermore, each STA can determine whether preemption is possible based on application execution status, etc. As another example, if there is a history of transmitted IP packets with a DSCP value in the DS field set to a value indicating accelerated forwarding within a specific time period, each STA can determine that preemption is possible. Furthermore, if the communication device's operation settings are set to indicate that the communication device will not perform preemptive transmission, the control unit 301, in conjunction with the setting management unit 305, determines that preemption is unlikely. Note that the first three digits of the DS field can be considered as an IP priority value, and if IP packets with a threshold value of "5" have been communicated within a certain time period, it can be determined that preemption is expected. Past communication data can also be used as input to estimate the probability that uplink transmission of low-latency data is likely to occur in the future, and the estimated probability can be used as a basis for determining whether preemption is possible. For example, inferences indicating the likelihood of preemption can be obtained by inputting past communication data into trained model data that has been trained using known techniques such as supervised learning or deep learning. In this case, each STA can determine whether preemption is expected to occur based on the probability obtained as an inference.Each STA can also be configured to report PO information together, as well as the expected amount of hypothetical data in the event of low-latency data.

[0096] Return to Figure 8 As explained in S801, the control unit 301 and the communication unit 206 cooperate to determine whether downlink data addressing the STA itself has been received from the AP. If it is determined that downlink data addressing the STA itself has been received from the AP, the process proceeds to S802; otherwise, if it is determined that no downlink data addressing the STA itself has been received from the AP, the process proceeds to S812.

[0097] In S802, the control unit 301, in cooperation with the communication unit 206 and the frame processing unit 303, receives downlink data addressed to the STA itself from the AP. The received data is processed by the frame processing unit 303 and, if necessary, passed to a higher layer, such as the IP layer or application layer. Next, in S803, the control unit 301 determines whether the low-latency data received from the higher layer for uplink transmission is stored in the transmission queue. If it is determined that the low-latency data is stored in the transmission queue, the process proceeds to S805; otherwise, it proceeds to S804. In S804, the control unit 301, in cooperation with the frame generation unit 302, generates a Block Ack frame.

[0098] Then, the control unit 301 cooperates with the communication unit 206 to transmit the generated instruction block acknowledgment frame to the AP 101. Note that the block acknowledgment transmitted in S804 does not include the aforementioned PI information.

[0099] On the other hand, in S805, the control unit 301 cooperates with the frame generation unit 302 to generate a frame containing block confirmation and information indicating the presence of preemptive data. Then, the control unit 301 cooperates with the communication unit 206 to transmit the frame containing block confirmation and information indicating the presence of preemptive data to the AP 101. In other words, the frame transmitted in S805 includes the aforementioned PI information. The PO information transmitted in S800 and the PI information transmitted in S805 serve to prompt the AP to issue a trigger frame. This will be used later. Figure 9 Describe the details.

[0100] In S806, the control unit 301 determines whether a trigger frame has been received from the AP. If a trigger frame has been received from the AP, the process proceeds to S807; otherwise, the process proceeds to S802 and performs processing for waiting and receiving additional downlink data.

[0101] Next, the processing upon receiving a trigger frame will be described starting from S807. In S807, the control unit 301 cooperates with the frame processing unit 303 to determine whether a transmission opportunity has been allocated to the STA itself via the trigger frame. If it is determined that a transmission opportunity has been allocated to the STA itself, the process proceeds to S808; otherwise, if it is determined that a transmission opportunity has not been allocated to the STA itself, the process proceeds to S810. More specifically, in Figure 5 If the AID12 subfield 509 described above includes the STA's own AID, the control unit 301 determines that a transmission opportunity has been allocated. Note that if the trigger frame specifies RA-RU, and the transmission opportunity is won by decreasing the aforementioned OBO counter, the process can also proceed to S808. Furthermore, if it is determined that the received trigger frame is a MU-RTS TXS trigger frame addressed to the STA itself, the control unit 301 determines that a transmission opportunity has been allocated to the STA itself.

[0102] In S808, control unit 301 waits for the IFS time. Note that during the waiting time, control unit 301 cooperates with frame processing unit 303 to generate a UL TB PPDU for transmitting uplink data stored in the transmission queue. After the IFS has passed, control unit 301 cooperates with communication unit 206 to transmit the UL TB PPDU containing the uplink data. This process assumes that each STA prioritizes storing such data in the UL TB PPDU if low-latency data is stored in the transmission queue. Note that if the received trigger frame is a MU-RTS TXS trigger frame, control unit 301 exclusively occupies the same bandwidth as the PPDU used to transmit the trigger frame. In other words, control unit 301 exclusively occupies the channel and transmits a non-TB format UHR PPDU to AP 101. Upon completion of uplink transmission processing, control unit 301 advances the processing to S810.

[0103] Next, in S810, the control unit 301 determines whether the duration of the TXOP acquired by the AP has elapsed. Specifically, when data reception begins in S801, the control unit 301 stores the time period of the TXOP acquired by the AP based on the value stored in the duration field. Then, the control unit 301 uses the stored time period and its internal clock to determine whether the duration of the TXOP acquired by the AP has elapsed. If it is determined that the duration of the TXOP acquired by the AP has elapsed, the process proceeds to S811; otherwise, if it is not determined that the duration of the TXOP acquired by the AP has elapsed, the process proceeds to S802 to wait for downlink data to be received from the AP.

[0104] In S811, the control unit 301 determines whether the operation has ended. If the operation is determined to be ended, a series of processing operations are completed, a shutdown process is performed, and the STA itself transitions to a power-off state. On the other hand, if the operation is not determined to be ended, the control unit 301 proceeds the processing to S800.

[0105] Next, other preemption control will be described. In S812, the control unit 301 determines whether the data to be transmitted is stored in the transmission queue and whether the channel is idle. If it is determined that the data to be transmitted is stored in the transmission queue and the channel is idle, the process proceeds to S813.

[0106] In S813, the control unit 301 performs processing for transmitting data stored in the transmission queue. This processing for transmitting data will be described using a flowchart later.

[0107] Next, in S814, the control unit 301 determines whether the channel is busy due to data communication in the BSS and reports information indicating possible preemption to the AP. This determination of whether the channel is busy due to data communication in the BSS can be achieved by comparing the value of the BSS color subfield included in the U-SIG (which is the preamble of the PPDU being received from the outside) with the STA management value of the BSS color belonging to the STA itself. If the value of the BSS color subfield matches the STA management value of the BSS color belonging to the STA, the control unit 301 determines that the channel is busy because it addresses the PPDU of the BSS belonging to the STA itself. On the other hand, if the value of the BSS color subfield does not match the STA management value of the BSS color belonging to the STA, the control unit 301 determines that the channel is not busy due to data communication in the BSS belonging to the STA itself. If both the condition that the channel is busy due to data communication in the BSS and the information indicating possible preemption reported to the AP are satisfied, the control unit 301 proceeds to S815. On the other hand, if it is determined that the channel is not busy due to data communication in the BSS (in other words, the channel is busy due to data communication in the OBSS), the control unit 301 will proceed to S816. Furthermore, if it is determined that information indicating a possible preemption should not be reported to the AP, the control unit 301 will proceed to S816.

[0108] In S816, the control unit 301 sets the STA's own NAV based on the time period information included in the received frame addressed to another device, and proceeds the processing to S811.

[0109] On the other hand, in S815, the control unit 301 cooperates with the communication unit 206 to wait for a trigger frame to be received from the AP, and determines whether a trigger frame has been received from the AP. If a trigger frame is received from the AP, the process proceeds to S807; otherwise, the process proceeds to S811. According to the above processing, even if another device in the BSS to which the STA belongs transmits a PPDU, the STA intending to report PO information will not set its NAV. Therefore, the STA reporting PO information becomes able to wait to receive a trigger frame.

[0110] Next, we will use Figure 9 This describes the communication control using AP 101. Figure 9 In the following description, the functional units of AP 101 are used as the syntactic subject of the description. The control unit 301 of AP 101 cooperates with the communication unit 206 to receive an indication from the STA regarding the possibility of preemption. This information is the aforementioned PO information, and as described in the STA-side control, this information is assumed to include the UHR OM field stored in the MAC header of the uplink data transmitted from each STA. Note that the mechanism for transmitting PO information is not limited to the above. The control unit 301 cooperates with the setup management unit 305 to manage the PO information received from each STA in association with that STA. Furthermore, when a report regarding the hypothetical amount of data expected in the event of low-latency data is received along with the PO information, this information is also managed in association with the STA from which the information originates. This information is appropriately referenced in the decision-making steps described later.

[0111] In S901, the control unit 301 determines whether there is downlink data to be transmitted to the STA. If it is determined that there is downlink data to be transmitted to the STA, the process proceeds to S902; otherwise, if it is not determined that there is downlink data to be transmitted to the STA, the process proceeds to S912.

[0112] First, we will describe downlink data transmission processing and uplink data preemption control in the case of downlink data transmission processing.

[0113] In S902, the control unit 301 cooperates with the communication unit 206 to ensure TXOP. For example, if the channel providing the network is idle and a CSMA / CA-based transmission opportunity is obtained, the AP 101 transmits the aforementioned RTS frame to ensure TXOP and also notifies the surrounding area that TXOP has been secured.

[0114] In S903, the control unit 301 transmits a frame containing downlink data to one or more STAs, the frame being generated in cooperation with the generation unit 302.

[0115] The transmission processing is performed in cooperation with the communication unit 206.

[0116] Next, in S904, the control unit 301, in cooperation with the communication unit 206 and the processing unit 303, determines whether a frame containing block acknowledgment information has been received from one or more STAs. If a frame containing block acknowledgment information is received, the process proceeds to S905; otherwise, the process proceeds to S903, and downlink data transmission continues.

[0117] In S905, the control unit 301 determines whether the received frame contains information indicating preemptive data. If the received frame contains information indicating preemptive data, the process proceeds to S908; otherwise, it proceeds to S906. The information received in S905 is the aforementioned PI information. Note that when information indicating the amount of data to be transmitted is received along with the PI information, the control unit 301 cooperates with the setting management unit 305 to manage information about the data amount in association with the source STA.

[0118] In S906, the control unit 301 refers to the PO information associated with each STA managed by the setting management unit 305 and determines whether it has received information indicating possible preemption from one or more STAs.

[0119] If it is determined that information indicating a possible preemption has been received from one or more STAs, the control unit 301 will proceed to S907. On the other hand, if it is determined that no information indicating a possible preemption has been received from one or more STAs, the control unit 301 will proceed to S911.

[0120] In S907, the control unit 301 determines whether the transmission interruption condition is met. If the condition is met, the process proceeds to S908; otherwise, it proceeds to S911. More specifically, the control unit 301 determines whether the transmission interruption condition is met based on the number of STAs that may preempt, the assumed data volume, and past communication history. Note that the control unit 301 of AP 101 can also determine that the transmission interruption condition is not met if it determines that the downlink data being transmitted by AP 101 itself is high-priority, low-latency data. In this case, the configuration can be such that the determination in S907 is performed again when the transmission of high-priority, low-latency data is completed. As another example, the configuration can be such that the transmission interruption condition is met if the number of STAs that may preempt exceeds a predetermined number and the time period corresponding to the threshold managed by the management unit has passed. Note that the configuration can also be such that the threshold is periodically updated based on the number of STAs that may preempt, the assumed data volume, and communication history. For example, the threshold can be updated every minute based on recent communication history and the assumed amount of updated data received from each STA. This processing allows the frequency of issuing trigger frames for preemption to be adjusted according to recent communication trends.

[0121] Next, in S908, the control unit 301 determines one or more STAs to be preempted. At this time, it also decides what size RU to allocate to each STA. Note that this determination process can be based on the aforementioned PO and PI information, the aforementioned assumed data volume, the expected data volume, past communication history, and information related to buffer status reports (BSRs) received from the STAs in the past.

[0122] Note that some RUs can also be configured as RA-RUs. Furthermore, when PI information is received from a STA and the STA has a large amount of data to transmit, it can be determined that the STA alone will occupy the entire channel and transmit uplink data for a specific time period. In the case of a STA occupying the entire channel, it is assumed that control unit 301 cooperates with generation unit 302 to generate an MU-RTS TXS trigger frame and transmit it to that STA.

[0123] The MU-RTS TXS trigger frame is used to share the TXOP acquired by the AP with another STA. The STA receiving this trigger frame is permitted to transmit a regular MU PPDU (not a TB PPDU) to the AP during the time period indicated in the trigger frame.

[0124] On the other hand, when it is determined that multiple STAs need to preempt, the control unit 301 and the generation unit 302 cooperate to generate a usage. Figure 5 The trigger frames are described as being of various types (basic type trigger frames and low-latency type trigger frames). Next, the control unit 301 collaborates with the communication unit 206 to transmit the generated trigger frames to multiple STAs.

[0125] In S909, control unit 301 waits for the duration of the IFS time and proceeds to S910 after the IFS time has elapsed. In S910, control unit 301, in cooperation with communication unit 206, attempts to receive UL TB PPDUs transmitted from multiple STAs triggered by a trigger frame. Furthermore, if the trigger frame transmitted by AP 101 is a MU-RTS TXS trigger frame, control unit 301 attempts to receive a UL PPDU transmitted from one STA triggered by the trigger frame. PPDUs successfully received as a result of the reception attempt are passed to processing unit 303 and processed by processing unit 303. Appropriately, user data stored in the PPDU is passed to higher layers, such as the IP layer or application layer. Furthermore, if the address of the received data is another STA in the BSS, the data is stored in the transmission queue of AP 101. At this time, it is assumed that high-priority data is stored in the high-priority transmission queue. Upon completion of receiving uplink data triggered by the trigger frame, control unit 301 proceeds to S911.

[0126] In S911, the control unit 301 determines whether the secured TXOP remains. If it is determined that the secured TXOP remains, the process proceeds to S903; otherwise, if it is not determined that the secured TXOP remains (i.e., if it is determined that no TXOP remains), the process proceeds to S900.

[0127] Next, a specific control method for preemptive communication of low-latency data while another STA is transmitting uplink data to AP 101 will be described. In S912, control unit 301 determines whether uplink data has been received from any STA connected to AP 101. If it is determined that uplink data has been received from any STA connected to AP 101, the process proceeds to S913. If it is determined that no uplink data has been received from any STA connected to AP 101, the process proceeds to S916.

[0128] In S913, the control unit 301 determines, in a manner similar to the processing described in S906, whether it has received information indicating a possible preemption from one or more STAs. If it is determined that information indicating a possible preemption has been received from one or more STAs, the control unit 301 proceeds to S914. On the other hand, if it is determined that no information indicating a possible preemption has been received from one or more STAs, the control unit 301 proceeds to S915.

[0129] In S914, the control unit 301 cooperates with the communication unit 206 to perform reception processing that takes preemption into account. This will be used later. Figure 10 The flowchart in section S915 describes the details of this process. On the other hand, in S915, control unit 301 performs a preemption-free reception process. This process is a preemption-free data reception process, similar to the PPDU reception process in IEEE 802.11ax and IEEE 802.11be. In this way, preemption control is not performed in the absence of a single STA that announces its intention to preempt.

[0130] Finally, in S916, the control unit 301 determines whether the operation has ended. If it determines that the operation has ended, the series of processing operations are completed, a shutdown process is performed, and the STA itself transitions to a power-off state. On the other hand, if it does not determine that the operation has ended, the control unit 301 proceeds the processing to S900.

[0131] Next, we will use Figure 10 The flowchart in the text describes the considerations. Figure 9 The details of the receive processing considering preemption are described in S914. In S1001, the control unit 301 of AP 101 cooperates with the communication unit 206 to receive uplink data from one or more STAs. In S1002, the control unit 301 cooperates with the communication unit 206 and the processing unit 303 to determine whether the reception of a PPDU is complete. If it is determined that the reception of a PPDU is complete, the process proceeds to S1003; otherwise, if it is not determined that the reception of a PPDU is complete, the process returns to the processing in S1001, and processing for receiving subsequent uplink data is performed.

[0132] In S1003, the control unit 301 determines whether the receive interruption condition is met. The specific determination condition in this determination is similar to the transmission interruption determination condition in the transmission process described in S907. If the receive interruption condition is met, the process proceeds to S1006; if the receive interruption condition is not met, the process proceeds to S1004.

[0133] Note that in S1003, if the uplink data being received by the AP is determined to be high-priority, low-latency data, the reception interruption condition can be deemed not to be met. In this case, the following configuration can be used: the judgment in S1003 can be performed again after the reception of the uplink data, which is high-priority, low-latency data, is completed.

[0134] In S1004, the control unit 301 cooperates with the generation unit 302 to generate a block acknowledgment for one or more STAs from which the uplink data originates. Then, the control unit 301 cooperates with the communication unit 206 to transmit the generated block acknowledgment to one or more STAs. Upon completion of the transmission, the control unit 301 proceeds to S1005.

[0135] In S1005, the control unit 301 determines whether the TXOP (Transmission Time Opportunity) for transmitting uplink data from the STA from which the uplink data originates remains. Specifically, when data reception begins in S1001, the control unit 301 stores the time period of the TXOP acquired by the STA based on the value stored in the duration field of the frame received from the STA. Then, the control unit 301 uses the stored time period and its internal clock to determine whether the duration of the TXOP acquired by the STA has elapsed.

[0136] If it is determined that the duration of the TXOP acquired by the STA has expired, the process proceeds to S900; otherwise, if it is not determined that the duration of the TXOP acquired by the STA has expired, the process proceeds to S1001 to wait for uplink data to be received from the STA.

[0137] Next, the process of reporting information indicating the occurrence of preemption to the STA and performing preemption involving low-latency data will be described. In S1006, the control unit 301 cooperates with the generation unit 302 to generate a frame containing block acknowledgment and information indicating that preemption has occurred for one or more STAs. Then, the control unit 301 cooperates with the communication unit 206 to transmit the generated frame to one or more STAs. Note that the following configuration can be adopted: the CAS control subfield is stored in the aforementioned HT control field, and the aforementioned information is stored in that field. For example, the following configuration can be adopted: B3 of the CAS control subfield is used to indicate whether preemption has occurred. In this embodiment, information indicating that preemption has occurred is reported to the STA by transmitting a block acknowledgment frame with B3 set to "1". By reporting this information, the occurrence of preemption can be appropriately reported to STAs that have secured transmission opportunities for uplink data. The operation of the STA receiving this report will be described later. Note that the transmission of a frame with "0" stored in B3 means reporting information to the STA indicating that preemption has not yet occurred.

[0138] Next, in S1007, the control unit 301, in cooperation with the generation unit 302 and the communication unit 206, determines one or more STAs to be preempted, and transmits a trigger frame to the determined one or more STAs. Since the specific process is similar to that described in S908, a further description is omitted.

[0139] In S1008, control unit 301 waits for the IFS time, and in S1009, control unit 301 cooperates with communication unit 206 and processing unit 303 to receive the UL TB PPDU and / or UL PPDU triggered by the trigger frame. Upon completion of the reception process, control unit 301 advances the processing to S1005.

[0140] Next, we will use Figure 11 This describes the process of transmitting uplink data via a STA as described in S813. In the case of transmitting uplink data to AP101, the STA connected to AP101 (such as any STA from STA 103-1 to 103-N) performs... Figure 11 Control within.

[0141] In S1101, the STA's control unit 301 collaborates with the generation unit 302 and the communication unit 206 to transmit uplink data. Next, in S1102, the control unit 301 determines whether the transmission of a PPDU is complete. If the transmission of a PPDU is determined to be complete, the process proceeds to S1103; otherwise, if the transmission of a PPDU is not determined to be complete, the process returns to the steps in S1101, and the transmission of uplink data continues.

[0142] In S1103, the control unit 301 cooperates with the communication unit 206 and the processing unit 303 to receive a frame containing block acknowledgment information. If it is determined that a frame containing block acknowledgment information has been received, the process proceeds to S1104; otherwise, if it is not determined that a frame containing block acknowledgment information has been received, the process returns to the processing in S1101.

[0143] In S1104, the control unit 301 determines whether the received frame contains information indicating that preemption has occurred. If it is determined that the received frame contains information indicating that preemption has occurred, the process proceeds to S1105; otherwise, if it is not determined that the received frame contains information indicating that preemption has occurred, the process proceeds to S1111.

[0144] In S1111, the control unit 301 determines whether the TXOP acquired by the STA for transmitting uplink data remains. If it determines that the STA has remaining TXOP for transmitting uplink data, the control unit 301 proceeds to S1101. On the other hand, if it determines that the STA has no remaining TXOP for transmitting uplink data, the control unit 301 completes a series of transmission processing steps and proceeds to S811.

[0145] Next, the preemption handling process in STA will be described. In S1105, the control unit 301 cooperates with the generation unit 302 and the communication unit 206 to interrupt the data transmission process.

[0146] In S1106, the control unit 301 cooperates with the communication unit 206 and the processing unit 303 to receive a trigger frame. In S1107, the control unit 301 determines whether a transmission opportunity has been allocated to the STA based on the received trigger frame. If the control unit determines that a transmission opportunity has been allocated to the STA based on the received trigger frame, the control unit 301 proceeds to S1108; otherwise, if the control unit determines that a transmission opportunity has not been allocated to the STA based on the received trigger frame, the control unit 301 proceeds to S1110.

[0147] Since this process is similar to S807, a description is omitted.

[0148] In S1108 and S1109, control unit 301 transmits the UL TB PPDU or UL PPDU after waiting for the IFS time. Since this process is similar to S808 and S809, its description is omitted. In this case, it is also assumed that low-latency data is preferentially stored in the UL TB PPDU or UL PPDU. Upon completion of the uplink data transmission process, control unit 301 advances the process to S1111.

[0149] On the other hand, in S1110, control unit 301 waits for a duration corresponding to the IFS time plus the transmission opportunity allocated by the trigger frame. Upon completion of the wait, the process proceeds to S1111. If the trigger frame issued by AP 101 does not allocate a transmission opportunity to the STA itself to allow the transmission of low-latency data, the above process causes the STA to wait until another STA completes its uplink transmission. After the waiting period preempted by the other STA ends, if TXOP remains, the STA can resume uplink transmission processing.

[0150] Note that this embodiment assumes that block acknowledgments are transmitted as acknowledgments of data reception, but is not limited to this. For example, an acknowledgment could also be a simple Ack. In this case, the PI information could be reported to another device along with the Ack. Furthermore, this embodiment assumes that the Short Interframe Spacing (SIFS) is used as the IFS time, but is not limited to this.

[0151] (Modified Example)

[0152] Alternatively, the following configuration can be used: In addition to the processing described in the above embodiments, the preemption control indicated in this variation is also performed. According to this variation, the STA preempts itself to transmit a new UL TB PPDU containing low-latency data during the transmission of the UL TB PPDU allocated to the STA itself while the STA itself is transmitting a UL TB PPDU. This will be used... Figure 12A and Figure 12B To describe the specific mechanism. Figure 12A This is a schematic diagram illustrating an example of preemption processing according to a variant, and Figure 12B An example of the U-SIG2 field that constitutes the preamble portion of a UL TB PPDU is shown.

[0153] First, AP 101 transmits the trigger frame described in S908. Each STA designated as the address destination of the trigger frame transmits a UL TB PPDU after the IFS time has elapsed. At this time, each STA determines whether preemption is possible. This determination can be performed in a manner similar to the first embodiment. STAs determined to be likely to preempt store information indicating the possibility of preemption in the preamble of the UL TB PPDU to transmit the preemption possibility to AP 101. Note that... Figure 12A This shows an example where STA 103-1 is judged to be possible for preemption, while STA 103-2 and STA 103-3 are not judged to be possible for preemption.

[0154] The control unit 301, which has identified a STA (such as STA 103-1) as potentially vulnerable to preemption, collaborates with the generation unit 302 to generate a TB PPDU. The TB PPDU's preamble stores information indicating the potential for preemption. Then, the control unit 301 of the STA identified as potentially vulnerable to preemption transmits the UL TB PPDU to the AP.

[0155] Information indicating potential preemption can be stored, for example, as... Figure 12BThe TB preemption flag field 1201 of U-SIG2, shown in 1021, indicates that preemption is possible during the transmission of a TB PPDU when a "1" is stored in this field, while a "0" indicates that preemption is not possible during the transmission of a TB PPDU. For example, this field can be configured to be stored in bit B2 of the U-SIG2 field. Note that this placement of the field is an example, and the TB preemption flag field can also be in bits B11 through B15 (in...). Figure 12B Any bit provided in (indicated to be ignored).

[0156] Return to Figure 12A The control unit 301, which has been identified as a potential preemptor of a STA, determines whether low-latency data has occurred and been stored in the transmission queue. If it determines that low-latency data has occurred and been stored in the transmission queue, it interrupts the transmission of the currently transmitting ULTB PPDU and transmits a signal called Endbreaker (EB) to AP 101 to indicate that an interruption has occurred. EB is a signal consisting of a specific sequence used to indicate that an interruption has occurred to another device. AP 101 receives and detects the EB signal. This detection allows it to know in advance that a new ULTB PPDU will be used for uplink transmission of low-latency data instead of the current uplink transmission. In this case, the STA identified as a potential preemptor completes the transmission of ULTB PPDU1 at a smaller size than initially expected when the trigger frame was received.

[0157] Next, in response to the elapsed IFS time since the completion of the EB signal transmission, the control unit 301, which has been determined to be a potential preemptor of the STA, transmits the UL TB PPDU containing low-latency data. AP 101 has already detected the EB signal and can therefore wait to receive the new UL TB PPDU in the RU assigned to the STA (e.g., STA 103-1). AP 101 then decodes the UL TB PPDU and, if necessary, forwards the data contained in the UL TB PPDU to another STA and / or to a higher level of AP 101.

[0158] According to the above processing, the STA can interrupt its own transmission while transmitting a UL TB PPDU and preemptively transmit a new UL TB PPDU containing low-latency data. This processing enables preemptive transmission of low-latency data without employing complex configurations such as replacing the data to be stored in the currently transmitted UL TB PPDU with high-priority data instead of the regular priority data to be transmitted.

[0159] <Other Embodiments>

[0160] The present invention can also be implemented by supplying a program for implementing one or more functions of the above embodiments to a system or device via a network or storage medium, and causing one or more processors of the computer of the system or device to read and execute the program. The present invention can also be implemented by a circuit (e.g., an ASIC) that implements one or more functions.

[0161] This invention is not limited to the embodiments described above, and various changes and modifications are possible without departing from the spirit and scope of the invention. Therefore, the claims are appended to disclose the scope of the invention.

[0162] This application claims the benefit of Japanese Patent Application 2023-065267, filed on April 12, 2023, the entire contents of which are incorporated herein by reference.

[0163] Explanation of reference numerals in the attached figures

[0164] 101 AP

[0165] 103-1 STA

[0166] 103-2 STA

[0167] 103-n STA

[0168] 202 Control Unit

[0169] 206 Communication Units

Claims

1. A communication device capable of wireless communication based on the IEEE 802.11 standard, characterized in that it comprises: A first transmission control unit, when receiving data transmitted from the access point to the communication device during a transmission opportunity obtained using an access point connected to the communication device, and when data to be transmitted to the outside with low latency is stored in the transmission queue of the communication device, transmits a frame containing information indicating acknowledgment of the received data and information related to preemption of low-latency data. as well as The second transmission control unit transmits data to the outside based on the receipt of a trigger frame issued after the frame is transmitted to the access point.

2. The communication device according to claim 1, characterized in that, Under specified conditions, the first transmission control unit transmits a second frame at a timing different from the timing for receiving data from the access point. The second frame does not contain information indicating acknowledgment of the access point, but contains information indicating that preemption involving low-latency data may occur.

3. The communication device according to claim 2, characterized in that, The second frame also contains second information relating to the hypothetical amount of data expected in the event of preemption, and the frame contains information indicating the amount of low-latency data expected to be transmitted.

4. The communication device according to any one of claims 1 to 3, characterized in that... Also includes: A receiving control unit controls reception after the frame is transmitted, causing the communication device to wait to receive the trigger frame.

5. The communication device according to any one of claims 1 to 4, characterized in that, The trigger frame contains information indicating a transmission opportunity for transmitting low-latency data.

6. A communication device capable of wireless communication based on the IEEE 802.11 standard, characterized in that it comprises: A first receiving control unit receives a frame from another communication device connected to the communication device, the frame containing information indicating acknowledgment of data transmitted by the communication device and information relating to preemption of low-latency data; A transmission control unit, upon receiving the frame, transmits a trigger frame to the other communication device to provide an uplink transmission opportunity for low-latency data. as well as The second receiving control unit attempts to receive uplink data frames transmitted in response to the trigger frame.

7. The communication device according to claim 6, characterized in that, The frame indicates a response to data transmitted by the communication device to the other communication device during a transmission opportunity obtained by the communication device, and includes at least information indicating confirmation of the data and information related to preemption.

8. The communication device according to claim 6 or 7, characterized in that, The trigger frame contains information indicating a transmission opportunity for transmitting low-latency data.

9. The communication device according to any one of claims 6 to 8, characterized in that, The first receiving control unit also receives a second frame addressed to the communication device, the second frame not containing information indicating confirmation, but containing information indicating that preemption involving low-latency data may occur.

10. The communication device according to claim 9, characterized in that, In addition to the aforementioned information, the second frame also contains second information relating to the hypothetical amount of data expected in the event of preemption, and the frame contains information indicating the amount of low-latency data expected to be transmitted.

11. The communication device according to claim 9 or 10, characterized in that, If it is determined that no information relating to preemption involving low-latency data has been received from any communication device connected to the communication device, the transmission control unit does not transmit the trigger frame for providing uplink transmission opportunities for low-latency data to the other communication device.

12. The communication device according to claim 11, characterized in that, If it is determined that information relating to preemption of low-latency data has been received from one or more other communication devices connected to the communication device, and uplink data is being received from the specific communication device, the transmission control unit interrupts the reception of uplink data from the specific communication device and transmits the trigger frame to the one or more other communication devices to provide an uplink transmission opportunity for low-latency data.

13. The communication device according to claim 12, characterized in that, If the uplink data being received from the specific communication device is low-latency data, the transmission control unit transmits the trigger frame to the one or more other communication devices after the reception of the low-latency data is completed, to provide an uplink transmission opportunity for the low-latency data.

14. A communication device capable of wireless communication based on the IEEE 802.11 standard, characterized in that it comprises: A first transmission control unit transmits information to an access point to which the communication device is connected, indicating potential preemption of low-latency data to be transmitted to the outside. as well as The second transmission control unit, when the low-latency data is stored in the transmission queue while the transmission of a TB PPDU containing uplink data of a specific size is being carried out based on a trigger frame received from the access point, terminates the transmission of the TB PPDU by switching the uplink data to be included in the TB PPDU to a size smaller than the specific size, and begins the transmission of a second TB PPDU containing part or all of the low-latency data stored in the transmission queue.

15. A control method for a communication device capable of wireless communication based on the IEEE 802.11 standard, the control method being characterized by comprising: A first transmission control step is used to transmit a frame containing information indicating acknowledgment of the received data and information relating to preemption of low-latency data when, during a transmission opportunity obtained using an access point connected to the communication device, data transmitted from the access point to the communication device is received and the data to be transmitted with low latency and to the outside is stored in the transmission queue of the communication device. as well as The second transmission control step is used to transmit data to the outside based on the receipt of a trigger frame issued after the frame is transmitted to the access point.

16. A control method for a communication device capable of wireless communication based on the IEEE 802.11 standard, the control method being characterized by comprising: A first receiving control step is used to receive a frame from another communication device connected to the communication device, the frame containing information indicating acknowledgment of data transmitted by the communication device and information relating to preemption of low-latency data; A transmission control step is used to transmit a trigger frame to the other communication device after receiving the frame, for providing an uplink transmission opportunity for low-latency data. as well as The second receive control step is used to attempt to receive uplink data frames transmitted in response to the trigger frame.

17. A control method for a communication device capable of wireless communication based on the IEEE 802.11 standard, the control method being characterized by comprising: A first transmission control step is used to transmit information to the access point to which the communication device is connected, indicating the possibility of preemption involving low-latency data to be transmitted to the outside. as well as The second transmission control step is used to complete the transmission of the TB PPDU by changing the uplink data to be included in the TB PPDU to a size smaller than the specific size when the low-latency data is stored in the transmission queue during the transmission of a TB PPDU containing uplink data of a specific size based on a trigger frame received from the access point, and to start the transmission of a second TB PPDU containing part or all of the low-latency data stored in the transmission queue.

18. A program for causing a computer to execute a control method for a communication device according to any one of claims 15 to 17.

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