Wireless communication method using multiple links and wireless communication terminal using same

Abstract

The present invention relates to a wireless communication method using a plurality of links and a wireless communication terminal using the same. A multi-link device using a plurality of links is disclosed. The multi-link device comprises: a transceiver unit; and a processor. When a multi-link device simultaneously transmits a plurality of PPDUs on a plurality of links using a transceiver unit, a processor determines a transmission end time of the plurality of PPDUs based on whether the multi-link device transmits a frame requesting an ACK.

Description

[0001] This application is a divisional application of patent application No. 202180020467.0 (International Application No. PCT / KR2021 / 003057), filed on September 9, 2022, with an international application date of March 11, 2021, entitled "A wireless communication method using multiple links and a wireless communication terminal using the method". Technical Field

[0002] This invention relates to a wireless communication method using multiple links and a wireless communication terminal using the method. Background Technology

[0003] In recent years, with the expansion of mobile device supply, wireless LAN technology, which can provide fast wireless internet services to mobile devices, has gained attention. Wireless LAN technology allows mobile devices, including smartphones, tablets, laptops, portable multimedia players, embedded devices, and more, to wirelessly access the internet in their homes, offices, or specific service areas based on short-range wireless communication technology.

[0004] Since using the 2.4 GHz frequency to support initial wireless LAN technology, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 has commercialized or developed various technical standards. First, IEEE 802.11b, using the 2.4 GHz band, supported a maximum communication speed of 11 Mbps. Compared to the significantly congested 2.4 GHz band, IEEE 802.11a, commercialized after IEEE 802.11b, used the 5 GHz band instead of 2.4 GHz to reduce interference and increased the communication speed to a maximum of 54 Mbps through the use of OFDM technology. However, a drawback of IEEE 802.11a is its shorter communication range compared to IEEE 802.11b. Furthermore, similar to IEEE 802.11b, IEEE 802.11g, using the 2.4 GHz band to achieve a maximum communication speed of 54 Mbps and satisfying backward compatibility, has attracted significant attention and, furthermore, outperforms IEEE 802.11a in terms of communication range.

[0005] Furthermore, IEEE 802.11n has been developed as a technical standard to overcome the limitations of communication speed, a weakness identified in wireless LANs. IEEE 802.11n aims to improve network speed and reliability and extend the operating range of wireless networks. More specifically, IEEE 802.11n supports high throughput (HT), with data processing speeds of up to 540 Mbps or higher, and further, it is based on multiple-input multiple-output (MIMO) technology, where multiple antennas are used on both sides of the transmitting and receiving units to minimize transmission errors and optimize data speed. Additionally, the standard can use a compilation scheme that transmits multiple superimposed copies to increase data reliability.

[0006] With the activation of the wireless LAN supply, and further, with the diversification of applications using wireless LAN, the need for new wireless LAN systems supporting higher throughput (Very High Throughput (VHT)) than those supported by IEEE 802.11n has gained attention. Among these, IEEE 802.11ac supports wide bandwidth (80 to 160 MHz) in the 5 GHz frequency band. The IEEE 802.11ac standard is defined only in the 5 GHz band, but initial 11ac chipsets even support operation in the 2.4 GHz band for backward compatibility with existing 2.4 GHz band products. Theoretically, according to this standard, wireless LAN speeds of up to 1 Gbps can be enabled for multiple stations, and a maximum single-link speed of up to 500 Mbps can be achieved. This is achieved through concepts that expand the wireless interface accepted by 802.11n, such as wider wireless frequency bandwidth (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256 QAM). Furthermore, IEEE 802.11ad has been offered as a solution for transmitting data using the 60 GHz band instead of the existing 2.4 GHz / 5 GHz band. IEEE 802.11ad is a transmission standard that provides speeds up to 7 Gbps using beamforming technology and is suitable for high bit-rate motion streaming, such as large-scale data or uncompressed HD video. However, its drawback is that the 60 GHz band is difficult to penetrate obstacles, limiting its use to devices operating in close proximity.

[0007] As a wireless LAN standard following 802.11ac and 802.11ad, the IEEE 802.11ax (High-Efficiency WLAN, HEW) standard is nearing completion, designed to provide efficient and high-performance wireless LAN communication in high-density environments where access points (APs) and terminals are concentrated. In 802.11ax-based wireless LAN environments, where high-density stations and access points (APs) are present, high-frequency efficiency communication should be provided indoors / outdoors, and various technologies have been developed to achieve this.

[0008] To support new multimedia applications, such as high-definition video and real-time gaming, new wireless LAN standards are being developed to increase maximum transmission rates. IEEE 802.11be (Extreme High Throughput, EHT), the 7th generation wireless LAN standard, is under development with the aim of supporting transmission rates up to 30Gbps in the 2.4 / 5 / 6 GHz band through wider bandwidth, increased spatial streaming, and multi-AP collaboration. Summary of the Invention

[0009] Technical issues

[0010] Embodiments of the present invention provide a wireless communication method using multiple links and a wireless communication terminal using the method.

[0011] Technical solution

[0012] A multi-link device using multiple links according to an embodiment of the present disclosure may include: a transceiver; and a processor. When the multi-link device uses the transceiver to simultaneously transmit multiple PPDUs across multiple links, the processor is configured to determine the transmission end time of the multiple PPDUs based on whether the multi-link device sends an ACK request frame.

[0013] When a multi-link device simultaneously transmits multiple PPDUs across multiple links, the processor is configured to align the ends of the multiple PPDUs that request ACKs.

[0014] When a multi-link device transmits multiple PPDUs simultaneously across multiple links, the processor is configured not to align the end of the PPDU containing only frames that do not request ACK with the end of the PPDU containing frames that request ACK.

[0015] Specifically, when a multi-link device transmits multiple PPDUs simultaneously across multiple links, the processor is configured to transmit the multiple PPDUs in such a way that the end of the PPDU containing only frames that do not request ACK is no later than the end of the PPDU containing frames that request ACK.

[0016] The ACK policy can be used to determine whether a frame requesting ACK is indeed a frame requesting ACK.

[0017] The frame requesting ACK is a data frame.

[0018] A multilink device is an AP multilink device, and the processor is configured to use a transceiver to send multiple PPDUs to non-AP multilink devices.

[0019] When a multi-link device receiving multiple PPDUs performs transmission on any one link, the multi-link device cannot perform reception on the other link.

[0020] A multi-link device using multiple links according to an embodiment of the present disclosure may include: a transceiver; and a processor. The processor is configured to enable the multi-link device to simultaneously receive multiple PPDUs from multiple links using the transceiver. The transmission end time of the multiple PPDUs can be determined based on whether a request ACK frame is sent in the multiple PPDUs.

[0021] Align the ends of multiple PPDUs that request ACK among multiple PPDUs.

[0022] The end of a PPDU that includes only frames that do not request ACK may not be aligned with the end of a PPDU that includes frames that request ACK.

[0023] The end of a PPDU that includes only frames that do not request ACK can be no later than the end of a PPDU that includes frames that request ACK.

[0024] The ACK policy can be used to determine whether a frame requesting ACK is indeed a frame requesting ACK.

[0025] The frame requesting ACK can be a data frame.

[0026] A multilink device is a non-AP multilink device, and the processor is configured to send multiple PPDUs from an AP multilink device using a receiver.

[0027] When a multi-link device performs transmission on any one link, it cannot perform reception on the other link.

[0028] The processor is configured to access channels using a channel access method across multiple links, employing a backoff counter. In this example, the initial value of the backoff counter is set by an obtained random number. The backoff counter is decremented by 1 when the accessed channel is idle during the time slot, and access is permitted when the backoff counter reaches 0. Even if the backoff counter reaches 0 in channel access on any of the multiple links, the processor may not perform transmissions on any of those links.

[0029] When no transmission is performed on any link, the processor can maintain the value of the backoff counter.

[0030] A method for operating a multi-link device using multiple links according to embodiments of the present disclosure may include: the multi-link device simultaneously receiving multiple PPDUs from multiple links using a transceiver. The transmission end time of the multiple PPDUs may be determined based on whether a request ACK frame is sent in the multiple PPDUs.

[0031] It can align the ends of multiple PPDUs that request ACK.

[0032] Beneficial effects

[0033] Embodiments of the present invention provide an effective wireless communication method for using multiple links and a wireless communication terminal using the method. Attached Figure Description

[0034] Figure 1 The illustration shows a wireless LAN system according to an embodiment of the present invention.

[0035] Figure 2 The illustration shows a wireless LAN system according to another embodiment of the present invention.

[0036] Figure 3 The illustration shows the configuration of a station according to an embodiment of the present invention.

[0037] Figure 4 The diagram illustrates the configuration of an access point according to an embodiment of the present invention.

[0038] Figure 5 This diagram illustrates the process of setting up a link between a STA and an AP.

[0039] Figure 6 The diagram illustrates the Carrier Sense Multiple Access (CSMA) / Collision Avoidance (CA) method used in wireless LAN communication.

[0040] Figure 7 The diagram illustrates an example of the format of the PLCP Protocol Data Unit (PPDU) used in each of the various standard generations.

[0041] Figure 8 The illustrations depict various Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU) formats according to embodiments of the present invention, as well as examples of methods for indicating such formats.

[0042] Figure 9 The illustration shows a multi-link device according to an embodiment of the present disclosure.

[0043] Figure 10 This is a diagram illustrating the simultaneous execution of transmissions in different links during multi-link operation according to an embodiment of the present disclosure.

[0044] Figure 11 This is a diagram illustrating the operation of a multi-link device simultaneously terminating transmissions in multiple links according to an embodiment of the present disclosure.

[0045] Figure 12 This diagram illustrates the operation of terminating transmission in any one of the links when a multi-link device performs transmissions in multiple links according to an embodiment of the present disclosure.

[0046] Figure 13 This is a diagram illustrating the operation of a multi-link device delaying transmission in another link when the multi-link device is performing transmission in any one link, according to an embodiment of the present disclosure.

[0047] Figure 14 This diagram illustrates the operation of terminating transmission in any one of the links when a multi-link device performs transmissions in multiple links according to an embodiment of the present disclosure.

[0048] Figure 15 This diagram illustrates the operation of terminating transmission in any one of the links first when a multi-link device performs transmissions in multiple links according to another embodiment of this disclosure.

[0049] Figure 16 This is a diagram illustrating how a multi-link device operates using a mapping between links and TIDs according to an embodiment of the present disclosure.

[0050] Figure 17 This is a diagram illustrating the operation of a station performing UL MU transmission according to an embodiment of the present disclosure.

[0051] Figure 18 This is a diagram illustrating a multi-link device performing multi-TID aggregation according to an embodiment of the present disclosure.

[0052] Figure 19 This is a diagram illustrating elements of information associated with the mapping between a link and a TID, according to an embodiment of the present disclosure.

[0053] Figure 20This is a diagram illustrating a station performing channel access in order to send a trigger frame according to an embodiment of the present disclosure.

[0054] Figure 21 This is a diagram illustrating the operation of a multi-link device performing transmission across multiple links according to an embodiment of the present disclosure.

[0055] Figure 22 This is a diagram illustrating the operation of setting up a NAV by a multi-link device according to an embodiment of the present disclosure.

[0056] Figure 23 This is a diagram illustrating the operation of setting up a NAV by a multi-link device according to an embodiment of the present disclosure.

[0057] Figure 24 This is a diagram illustrating a station of a multi-link device according to an embodiment of the present disclosure suspending channel access or transmission due to receiving a PPDU from another station of the multi-link device and resuming channel access or transmission.

[0058] Figure 25 This is a diagram illustrating a method by which a multi-link device sends a response to a trigger frame when a NAV is set for the multi-link device and a trigger frame is received, according to an embodiment of the present disclosure. Detailed Implementation

[0059] In consideration of the functionality of this invention, the terminology used in this specification employs currently widely used and common terms; however, the terminology may change according to the intent, habits, and emergence of new technologies of those skilled in the art. Furthermore, in certain cases, there are terms arbitrarily chosen by the applicant, and in such cases, their meaning will be described in the corresponding descriptive section of the invention. Therefore, it should be understood that the terminology used in this specification should be analyzed not only based on the name of the term, but also on its substantive meaning and the content of the entire specification.

[0060] Throughout this specification and the following claims, when an element is described as being “coupled” to another element, that element may be “directly coupled” to the other element or “electrically coupled” to the other element via a third element. Furthermore, unless expressly stated otherwise, the word “comprising” will be understood to implicitly include the stated element but does not exclude any other element. Additionally, limitations based on specific thresholds, such as “or more” or “or less”, may be appropriately replaced by “greater than” or “less than”, respectively.

[0061] In this invention, fields and subfields can be used interchangeably.

[0062] Figure 1 The illustration shows a wireless LAN system according to an embodiment of the present invention.

[0063] Figure 1 This diagram illustrates a wireless LAN system according to an embodiment of the present invention. The wireless LAN system includes one or more Basic Service Sets (BSSs), and a BSS represents a set of devices that have successfully synchronized with each other to communicate. Typically, a BSS can be divided into a Infrastructure BSS and Independent BSSs (IBSSs), and Figure 1 The diagram shows the basic structure BSS between them.

[0064] like Figure 1 As shown, the infrastructure BSS (BSS1 and BSS2) includes one or more stations STA1, STA2, STA3, STA4 and STA5, access points AP-1 and AP-2 as stations providing distributed services, and a distributed system (DS) connecting multiple access points AP-1 and AP-2.

[0065] A station (STA) is a predetermined device comprising a Media Access Control (MAC) conforming to the IEEE 802.11 standard and a physical layer interface for wireless media, and broadly includes both non-access point (non-AP) stations and access point (AP) stations. Furthermore, in this specification, the term "terminal" may be used to refer to a non-AP STA, or an AP, or both. A station for wireless communication includes a processor and a communication unit, and according to embodiments, may further include a user interface unit and a display unit. The processor can generate frames to be transmitted via a wireless network, or process frames to be received via a wireless network, and further performs various processes for controlling the station. Additionally, the communication unit is functionally connected to the processor and transmits and receives frames via the wireless network for the station. According to the invention, "terminal" can be used as a term including user equipment (UE).

[0066] An access point (AP) is an entity that provides access to a distributed system (DS) via wireless media used by its associated stations. In an infrastructure BSS, communication between non-AP stations is generally performed via the AP, but direct communication between non-AP stations is even permitted when a direct link is configured. In this invention, AP is used as a concept encompassing a Personal BSS Coordination Point (PCP), and broadly can include concepts including a central controller, base station (BS), node B, base transceiver system (BTS), and site controller. In this invention, AP can also be referred to as a base station wireless communication terminal. The term base station wireless communication terminal can be used broadly to include AP, base station, eNB (i.e., e-node B), and transport point (TP). Furthermore, a base station wireless communication terminal can include various types of wireless communication terminals that allocate media resources and perform scheduling of communication with multiple wireless communication terminals.

[0067] Multiple infrastructure BSSs can be interconnected via a distributed system (DS). In this case, the multiple BSSs connected via the distributed system are called an extended service set (ESS).

[0068] Figure 2 The illustration shows a standalone BSS according to another embodiment of the present invention, which is a wireless LAN system. Figure 2 In the embodiments, with Figure 1 Same or corresponding Figure 1 Repeated descriptions of certain embodiments will be omitted.

[0069] Because in Figure 2 The BSS3 shown in the diagram is an independent BSS and does not include the AP. All stations STA6 and STA7 are not connected to the AP. Independent BSSs are not allowed to access distributed systems and form self-contained networks. Within an independent BSS, the corresponding stations STA6 and STA7 can be directly interconnected.

[0070] Figure 3 This is a block diagram illustrating the configuration of station 100 according to an embodiment of the present invention. (As shown in...) Figure 3 As shown in the figure, the station 100 according to an embodiment of the present invention may include a processor 110, a communication unit 120, a user interface unit 140, a display unit 150, and a memory 160.

[0071] First, the communication unit 120 transmits and receives wireless signals, such as wireless LAN packets, and can be embedded in the station 100 or provided as a peripheral. According to embodiments, the communication unit 120 may include at least one communication module using different frequency bands. For example, the communication unit 120 may include communication modules with different frequency bands (such as 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz). According to embodiments, the station 100 may include communication modules using frequency bands of 7.125 GHz or higher, and communication modules using frequency bands of 7.125 GHz or lower. Each communication module can perform wireless communication with an AP or external station according to the wireless LAN standard of the frequency band supported by the respective communication module. The communication unit 120 may operate only one communication module at a time, or multiple communication modules simultaneously, depending on the performance and requirements of the station 100. When the station 100 includes multiple communication modules, each communication module may be implemented by an independent component, or multiple modules may be integrated into a single chip. In embodiments of the invention, the communication unit 120 may represent a radio frequency (RF) communication module for processing RF signals.

[0072] Secondly, the user interface unit 140 includes various types of input / output devices provided in the station 100. That is, the user interface unit 140 can receive user input using various input devices, and the processor 110 can control the station 100 based on the received user input. Furthermore, the user interface unit 140 can execute outputs based on commands from the processor 110 using various output devices.

[0073] Next, the display unit 150 outputs an image on the display screen. The display unit 150 can output various display objects based on control commands from the processor 110, such as content executed by the processor 110 or a user interface. Furthermore, the memory 160 stores the control program and various result data used in the station 100. The control program may include the access program required for the station 100 to connect to the AP or an external station.

[0074] The processor 110 of the present invention can execute various commands or programs and process data in the station 100. Furthermore, the processor 110 can control various units of the station 100 and control data transmission / reception within the units. According to an embodiment of the present invention, the processor 110 can execute a program for accessing an AP stored in the memory 160 and receive communication configuration messages sent by the AP. Furthermore, the processor 110 can read information about the priority conditions of the station 100 included in the communication configuration messages and request access to the AP based on the information about the priority conditions of the station 100. The processor 110 of the present invention can represent the main control unit of the station 100, and according to an embodiment, the processor 110 can represent a control unit for individually controlling certain components of the station 100 (e.g., communication unit 120, etc.). That is, the processor 110 can be a modem or modulator / demodulator for modulating wireless signals transmitted to the communication unit 120 and demodulating wireless signals received from the communication unit 120. The processor 110 controls various operations of wireless signal transmission / reception of the station 100 according to an embodiment of the present invention. Detailed embodiments thereof will be described below.

[0075] exist Figure 3 The station 100 illustrated in the diagram is a block diagram according to an embodiment of the present invention, where the separate blocks are illustrated as logically distinct device elements. Therefore, the device elements can be installed on a single chip or multiple chips depending on the device design. For example, the processor 110 and the communication unit 120 can be implemented as a single chip or as separate chips. Furthermore, in embodiments of the present invention, certain components of the station 100, such as the user interface unit 140 and the display unit 150, may be selectively provided in the station 100.

[0076] Figure 4This is a block diagram illustrating the configuration of AP 200 according to an embodiment of the present invention. (As shown in...) Figure 4 As illustrated in the figure, the AP 200 according to an embodiment of the present invention may include a processor 210, a communication unit 220, and a memory 260. Figure 4 In the AP200 components, and... Figure 2 The components of station 100 are the same or correspond to Figure 2 Repeated descriptions of parts of station 100 will be omitted.

[0077] refer to Figure 4 The AP 200 according to the invention includes a communication unit 220 that operates a BSS in at least one frequency band. (As in...) Figure 3 As described in the embodiments, the communication unit 220 of AP 200 may also include multiple communication modules using different frequency bands. That is, AP 200 according to embodiments of the present invention may together include two or more communication modules in different frequency bands (e.g., 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz). Preferably, AP 200 may include communication modules using frequency bands of 7.125 GHz or higher, and communication modules using frequency bands of 7.125 GHz or lower. Each communication module may perform wireless communication with the station according to the wireless LAN standard of the frequency band supported by the respective communication module. Communication unit 220 may operate one communication module at a time, or operate multiple communication modules simultaneously, depending on the performance and requirements of AP 200. In embodiments of the present invention, communication unit 220 may represent a radio frequency (RF) communication module for processing RF signals.

[0078] Next, memory 260 stores the control program and various result data used in AP 200. The control program may include an access program for managing station access. Furthermore, processor 210 can control the various units of AP 200 and control data transmission / reception within the units. According to an embodiment of the invention, processor 210 can execute the program for access stations stored in memory 260 and send communication configuration messages for one or more stations. In this case, the communication configuration message may include information about access priority conditions for each station. Furthermore, processor 210 performs access configuration according to the access request of a station. According to an embodiment, processor 210 may be a modem or modulator / demodulator for modulating wireless signals transmitted to communication unit 220 and demodulating wireless signals received from communication unit 220. Processor 210 controls various operations, such as wireless signal transmission / reception of AP 200, according to embodiments of the invention. Detailed embodiments thereof will be described below.

[0079] Figure 5This is a diagram illustrating the process of setting up a link between a STA and an AP.

[0080] refer to Figure 5 In a broad sense, the link between STA 100 and AP 200 is set up through three steps: scanning, authentication, and association. First, the scanning step is where STA 100 obtains access information from the BSS operated by AP 200. Methods for performing the scan include a passive scanning method, in which AP 200 obtains information by periodically sending beacon messages (S101), and an active scanning method, in which STA 100 sends a probe request to AP (S103) and obtains access information by receiving a probe response from AP (S105).

[0081] STA 100, having successfully received wireless access information during the scanning step, performs an authentication step by sending an authentication request (S107a) and receiving an authentication response from AP 200 (S107b). After performing the authentication step, STA 100 performs an association step by sending an association request (S109a) and receiving an association response from AP 200 (S109b). In this specification, association primarily refers to wireless association; however, the invention is not limited thereto, and association can broadly include both wireless and wired associations.

[0082] Meanwhile, the 802.1X-based authentication step (S111) and the IP address acquisition step via DHCP (S113) can be performed separately. Figure 5 In this context, authentication server 300 is the server that handles 802.1X-based authentication for STA 100, and can exist in a physical association with AP 200 or as a standalone server.

[0083] Figure 6 This is a diagram illustrating the Carrier Sensing Multiple Access (CSMA) / Collision Avoidance (CA) method used in wireless LAN communication.

[0084] Terminals performing wireless LAN communication check channel busy by performing carrier sensing before transmitting data. When a wireless signal of predetermined strength or greater is sensed, the corresponding channel is determined to be busy, and the terminal delays access to that channel. This process is called Clear Channel Assessment (CCA), and the level at which a corresponding signal is sensed is called the CCA threshold. When a terminal receives a wireless signal with a CCA threshold or higher that indicates it is the receiving terminal, the terminal processes the received wireless signal. Conversely, when no wireless signal is detected in the corresponding channel, or a wireless signal with a strength less than the CCA threshold is detected, the channel is determined to be idle.

[0085] When the channel is determined to be idle, each terminal with data to transmit performs a backoff procedure after an inter-frame interval (IFS) period, the duration of which depends on the specific terminal, such as an Arbitrated IFS (AIFS), PCF IFS (PIFS), etc. According to this embodiment, AIFS can be used as a component to replace the existing DCF IFS (DIFS). During the idle period of the channel, each terminal waits while decreasing the slot time by a random number determined by the corresponding terminal, and the terminal that has completely exhausted the slot time attempts to access the corresponding channel. Thus, the interval during which each terminal performs the backoff procedure is called the contention window interval. In this case, the random number is called a backoff counter. That is, the initial value of the backoff counter can be set as an integer, which is the random number obtained by the UE. If the UE detects that the channel is idle during the slot time, the UE can decrement the backoff counter by 1. Furthermore, if the backoff counter reaches 0, the UE can be allowed to perform channel access in the corresponding channel. Therefore, if the channel is idle during the AIFS time and the slot time of the backoff counter, the UE can be allowed to transmit.

[0086] When a specific terminal successfully accesses the channel, the corresponding terminal can transmit data through the channel. However, when a terminal attempting to access the channel conflicts with another terminal, the conflicting terminals are each assigned a new random number to re-execute the backoff process. According to an embodiment, this can be done within the range (2... Within the range (CW), a new random number is determined for each terminal, within which (2... The contention window (CW) is twice the range of random numbers previously assigned to the respective terminals. Simultaneously, each terminal attempts access by performing a backoff procedure again in the next contention window interval, and in this case, each terminal begins the backoff procedure from the remaining time slot of the previous contention window interval. In this way, individual terminals performing wireless LAN communication can avoid mutual collisions on specific channels.

[0087] <Examples of various PPDU formats>

[0088] Figure 7 The diagram illustrates an example of the format of the PLCP Protocol Data Unit (PPDU) used in each of the various standard generations. More specifically, Figure 7 The illustration in (a) is based on an embodiment of the conventional PPDU format of 802.11a / g. Figure 7 The illustration in (b) is based on an embodiment using the 802.11ax HE PPDU format, and Figure 7 (c) illustrates an embodiment based on a non-traditional PPDU (i.e., EHTPPDU) of 802.11be. Figure 7(d) shows the detailed field configuration of RL-SIG and L-SIG, which are commonly used in the PPDU format.

[0089] refer to Figure 7 (a) The preamble of a conventional PPDU includes a conventional short training field (L-STF), a conventional long training field (L-LTF), and a conventional signal field (L-SIG). In embodiments of the present invention, L-STF, L-LTF, and L-SIG may be referred to as conventional preambles.

[0090] refer to Figure 7 (b) The HE PPDU preamble also includes, in a conventional preamble, a repeated conventional short training field (RL-SIG), a high-efficiency signal A field (HE-SIG-A), a high-efficiency signal B field (HE-SIG-B), a high-efficiency short training field (HE-STF), and a high-efficiency long training field (HE-LTF). In embodiments of the present invention, RL-SIG, HE-SIG-A, HE-SIG-B, HE-STF, and HE-LTF may be referred to as HE preambles. The detailed configuration of the HE preamble can be modified according to the HE PPDU format. For example, HE-SIG-B may only be used in the HE MU PPDU format.

[0091] refer to Figure 7 (c) The EHT PPDU also includes, in its conventional preamble, a repeated conventional short training field (RL-SIG), a universal signal field (U-SIG), and a very high throughput signal A field (EHT-SIG-A), a very high throughput signal B field (EHT-SIG-B), a very high throughput short training field (EHT-STF), and a very high throughput long training field (EHT-LTF). In embodiments of the present invention, RL-SIG, EHT-SIG-A, EHT-SIG-B, EHT-STF, and EHT-LTF may be referred to as EHT preambles. The specific configuration of non-conventional preambles can be modified according to the EHT PPDU format. For example, EHT-SIG-A and EHT-SIG-B may be used only in a portion of the EHTPPDU format.

[0092] 64-FFT OFDM is applied to the L-SIG field included in the preamble of the PPDU, and the L-SIG field comprises a total of 64 subcarriers. Of these 64 subcarriers, 48 ​​subcarriers other than the guard subcarrier, DC subcarrier, and pilot subcarrier are used for L-SIG data transmission. BPSK and a modulation and coding scheme (MCS) with a code rate of 1 / 2 are applied to the L-SIG, so the L-SIG can include a total of 24 bits of information. Figure 7 (d) shows the configuration of the 24-bit information of L-SIG.

[0093] refer to Figure 7 (d) L-SIG includes the L_RATE and L_LENGTH fields. The L_RATE field consists of 4 bits and indicates the MCS used for data transmission. Specifically, the L_RATE field indicates a value of 6 / 9 / 12 / 18 / 24 / 36 / 48 / 54 Mbps obtained by combining modulation schemes such as BPSK / QPSK / 16-QAM / 64-QAM with inefficient values ​​such as 1 / 2, 2 / 3, 3 / 4, etc. The total length of the corresponding PPDU can be indicated by combining the information from the L_RATE and L_LENGTH fields. In non-traditional PPDU formats, the L_RATE field is configured with a minimum rate of 6 Mbps.

[0094] The L_LENGTH field is in bytes and is allocated a total of 12 bits, allowing for up to 4095 signal notifications. The length of the PPDU can be indicated in conjunction with the L_RATE field. Traditional and non-traditional terminals may interpret the L_LENGTH field differently.

[0095] First, the method for interpreting the length of the PPDU using the L_LENGTH field through traditional or non-traditional terminals is as follows. When the L_RATE field is set to 6 Mbps, it is possible to transmit 3 bytes (i.e., 24 bits) within 4 µs, where 4 µs is the duration of one symbol in a 64 FFT. Therefore, the number of symbols based on 64 FFT after L-SIG is obtained by adding the 3 bytes corresponding to the SVC field and the tail field to the value of the L_LENGTH field and dividing it by the 3 bytes of transmission as a symbol. The corresponding PPDU length, i.e., the reception time (i.e., RXTIME), is obtained by multiplying the obtained number of symbols by 4 µs as a symbol duration and then adding the 20 µs used for transmitting L-STF, L-LTF, and L-SIG. This can be represented by the following Equation 1.

[0096] [Equation 1]

[0097] in this case, This represents the smallest natural number greater than or equal to x. Since the maximum value of the L_LENGTH field is 4095, the length of the PPDU can be set to up to 5.464 ms. Non-traditional terminals sending PPDUs should set the L_LENGTH field as shown in Equation 2 below.

[0098] [Equation 2]

[0099] Here, TXTIME is the total transmission time that makes up the corresponding PPDU, and is represented by Equation 3 below. In this case, TX represents the transmission time of X.

[0100] [Equation 3]

[0101] Referring to the equation above, the length of the PPDU is calculated based on the up-rounded value of L_LENGTH / 3. Therefore, for random values ​​of k, three different values ​​of L_LENGTH={3k+1, 3k+2, 3(k+1)} indicate the same PPDU length.

[0102] refer to Figure 7 (e) The Universal SIG (U-SIG) field continues to exist in subsequent generations of EHT PPDUs and WLAN PPDUs, and is used to classify PPDUs of a generation including 11be. U-SIG is an OFDM 2 symbol based on 64 FFT and can transmit a total of 52 bits of information. Of these 52 bits, 43 bits, excluding the 9 bits for CRC / tail, are mainly divided into a Version Independent (VI) field and a Version Dependent (VD) field.

[0103] The VI bits enable the current bit configuration to be maintained subsequently, so that even if a next-generation PPDU is defined, the current 11be terminal can obtain information about the PPDU through the VI fields of the PPDU. For this purpose, the VI fields include PHY version, UL / DL, BSS color, TXOP, and a reserved field. The PHY version field is 3 bits and is used to sequentially classify 11be and subsequent generations of wireless LAN standards into versions. The value for 11be is 000b. The UL / DL field identifies whether the PPDU is an uplink / downlink PPDU. The BSS color indicates the identifier of each BSS defined in 11ax and has a value of 6 bits or more. The TXOP indicates the transmission opportunity duration sent in the MAC header, where the PPDU can infer the length of the TXOP included in it by adding the TXOP to the PHY header without having to decode the MPDU, and the TXOP has a value of 7 bits or more.

[0104] The VD field contains signaling information useful only for the 11be version of the PPDU and can include fields common to any PPDU format, such as the PPDU format and BW, as well as fields defined differently for each PPDU format. The PPDU format is a classifier that categorizes EHT Single User (SU), EHT Multi-User (MU), EHT Trigger-Based (TB), EHT Extended Range (ER) PPDUs, etc. The BW field signals five basic PPDU BW options (BW, which can be set to 20 MHz) at 20, 40, 80, 160 (80+80), and 320 (160+160) MHz. The signaling is expressed as a power of 2 (which can be referred to as the basic BW), and various residual PPDU BWs configured via preamble piercing. After signaling at 320MHz, signaling can be executed in some 80MHz pierced form. The pierced and modified channel type can be signaled directly in the BW field, or the pierced and modified channel type can be signaled using the BW field along with fields appearing after the BW field (e.g., fields within the EHT-SIG field). If the BW field is configured with 3 bits, a total of 8 BW signalings can be executed, and therefore up to 3 signalings can be executed in pierced mode. If the BW field is configured with 4 bits, a total of 16 BW signalings can be executed, and therefore up to 11 signalings can be executed in pierced mode.

[0105] The fields following the BW field vary depending on the type and format of the PPDU. MU PPDUs and SU PPDUs can be signaled in the same PPDU format. Fields used for classification between MU and SU PPDUs can precede the EHT-SIG field, and additional signaling can be applied to this field. Both SU and MU PPDUs include the EHT-SIG field, but some fields not needed in the SU PPDU can be compressed. Information about fields that have been compressed can be omitted or can have a smaller size than the original fields included in the MU PPDU. For example, in the case of SU PPDUs, common fields of EHT-SIG can be omitted or replaced, or the SU PPDU can have a different configuration, where user-specific fields are replaced, reduced to one, etc.

[0106] Alternatively, the SU PPDU may also include a compression field indicating whether compression is performed, and a portion of a field (e.g., the RA field, etc.) may be omitted depending on the value of the compression field.

[0107] If a portion of the EHT-SIG field of the SU PPDU is compressed, the information to be included in the compressed field can also be signaled in the uncompressed field (e.g., the common field, etc.). The MU PPDU corresponds to a PPDU format for simultaneous reception by multiple users, and therefore requires the EHT-SIG field to be transmitted after the U-SIG field, and the amount of information transmitted can vary. That is, multiple MU PPDUs are sent to multiple STAs, such that each STA should identify the location of the RU to which the MU PPDU was transmitted, the STA to which the RU is assigned, and whether the transmitted MU PPDU has been sent to the STA itself. Therefore, the AP should transmit this information by including the above information in the EHT-SIG field. For this purpose, information for valid transmission of the EHT-SIG field is signaled in the U-SIG field, and this can correspond to the MCS as a modulation method and / or the number of symbols in the EHT-SIG field. The EHT-SIG field can include information about the size and location of the RU assigned to each user.

[0108] In the case of SU PPDU, multiple RUs can be assigned to a STA, and these RUs can be consecutive or discontinuous. If the RUs assigned to the STA are discontinuous, the STA should identify the intermediate punched RUs in order to effectively receive the SUPPDU. Therefore, the AP can send a SU PPDU that includes information about the punched RUs among those assigned to the STA (e.g., the punching pattern of the RUs, etc.). That is, in the case of SU PPDU, a punching mode field can be included in the EHT-SIG field. This punching mode field includes information indicating the punching pattern in bitmap format, etc., and whether a punching mode has been applied. The punching mode field can signal the type of discontinuous channel occurring within the bandwidth.

[0109] The types of discontinuous channels notified by signals are limited, and the BW and discontinuous channel information of the SU PPDU are indicated by the combination of the BW field value and the SU PPDU. For example, the SU PPDU is a PPDU sent only to a single terminal, so that the STA can identify the bandwidth allocated to itself via the BW field included in the PPDU, and the SU PPDU can identify the punctured resources in the allocated bandwidth via the punctured mode field of the EHT-SIG field or U-SIG field included in the PPDU. In this case, the terminal can receive the PPDU in the remaining resource units after excluding the specific channels of the punctured resource units. Multiple RUs allocated to the STA can be configured by different frequency bands or tones.

[0110] To reduce the signaling overhead of the SU PPDU, only a limited number of discontinuous channel types are signaled. Puncture can be performed on each 20MHz sub-channel. Therefore, if puncturing is performed on a BW (such as 80, 160, and 320MHz) with a large number of 20MHz sub-channels, then in the case of 320MHz, the discontinuous channel type (if puncturing only the edge 20MHz is also considered discontinuous) should be signaled by indicating whether each of the remaining 15 20MHz sub-channels after excluding the main channel is used. Thus, considering the low transmission rate of the signaling section, allocating 15 bits to signal the discontinuous channel type transmitted by a single user could be excessive signaling overhead.

[0111] This invention proposes a technique for signaling the discontinuous channel type of a SU PPDU, and illustrates the discontinuous channel type determined according to the proposed technique. This invention also proposes a technique for signaling each of the puncture types in a 320MHz BW configuration of a SU PPDU, specifically for the primary 160MHz and secondary 160MHz puncture types.

[0112] One embodiment of the present invention proposes a technique for configuring a PPDU indicated by a preamble piercing (BW) value differently depending on the PPDU format notified by a signal in the PPDU format field. Assuming the BW field is 4 bits, and in the case of an EHTSU PPDU or TB PPDU, a 1-symbol EHT-SIG-A can be notified by a signal after U-SIG, or EHT-SIG-A can be notified at all. Therefore, considering this, it is necessary to fully signal up to 11 piercing modes via the BW field of U-SIG alone. However, in the case of an EHT MU PPDU, EHT-SIG-B is notified by a signal after U-SIG, thus allowing up to 11 piercing modes to be signaled in a different way than the SU PPDU method. In the case of an EHT ER PPDU, the BW field can be configured to be 1 bit to signal whether the EHT ER PPDU uses a 20MHz or 10MHz band. Further details will follow. Figure 11 and Figure 12 The document describes in detail the perforation pattern for each PPDU type.

[0113] Figure 7(f) illustrates the configuration of the format-specific fields of the VD field when an EHT MU PPDU is indicated in the PPDU format field of the U-SIG. In the case of a MU PPDU, SIG-B is necessary; it is a signaling field used for simultaneous reception by multiple users and can be sent after U-SIG without a separate SIG-A. Therefore, information for decoding SIG-B should be signaled in the U-SIG. These fields include SIG-B MCS, SIG-B DCM, the number of SIG-B symbols, SIG-B compression, and the number of EHT-LTF symbols.

[0114] Figure 8 The illustration shows examples of various Ultra High Throughput (EHT) Physical Protocol Data Unit (PPDU) formats according to embodiments of the present invention, as well as methods for indicating such formats.

[0115] Reference Figure 8 A PPDU can include a preamble and a data portion, and can be classified as an EHT PPDU format based on the U-SIG field included in the preamble. Specifically, the PPDU format field included in the U-SIG field can indicate whether the PPDU is an EHT PPDU.

[0116] Figure 8 (a) shows an example of the EHT SU PPDU format for a single STA. The EHT SU PPDU is a PPDU used for single-user (SU) transmissions between an AP and a single STA, and the EHT-SIG-A field for additional signaling can be located after the U-SIG field.

[0117] Figure 8 (b) shows an example of the EHT trigger-based PPDU format corresponding to the EHT PPDU transmitted based on the trigger frame. The EHT trigger-based PPDU is an EHT PPDU transmitted based on the trigger frame and is an uplink PPDU used in response to the trigger frame. Unlike the EHT SU PPDU, the EHT-SIG-A field is not located after the U-SIG field in the EHT PPDU.

[0118] Figure 8 (c) shows an example of an EHT MU PPDU format corresponding to an EHT PPDU for multiple users. An EHT MU PPDU is a PPDU used to send PPDUs to one or more STAs. In the EHT MU PPDU format, the HE-SIG-B field may follow the U-SIG field.

[0119] Figure 8(d) shows an example of the EHT ERSU PPDU format, which is used for transmission with a single user across an extended range of STAs. Figure 8 Compared to the EHT SU PPDU described in (a), the EHT ER SU PPDU can be used for single-user transmission with a wider range of STAs, and the U-SIG field can be repeatedly positioned on the time axis.

[0120] Figure 8 The EHT MU PPDU described in (c) can be used by the AP to perform downlink transmissions to multiple STAs. Here, the EHT MU PPDU may include scheduling information that allows multiple STAs to simultaneously receive PPDUs sent from the AP. The EHT MU PPDU may transmit the sender's and / or receiver's AID information of the PPDU sent via the user-specific field of EHT-SIG-B to the STA. Therefore, multiple terminals that have received the EHT MU PPDU can perform spatial reuse operations based on the AID information included in the user-specific field of the preamble of the received PPDU.

[0121] Specifically, the Resource Unit Allocation (RA) field of the HE-SIG-B field included in the HE MU PPDU can include information about the configuration (e.g., the partitioning of resource units) of resource units within a specific bandwidth (e.g., 20 MHz, etc.) of the frequency axis. That is, the RA field can indicate the configuration of resource units partitioned within the bandwidth used for the transmission of the HE MU PPDU so that the STA can receive the PPDU. Information about the STA allocated (or designated) to each partitioned resource unit can be included in the user-specific fields of the EHT-SIG-B field for transmission to the STA. That is, the user-specific fields can include one or more user fields corresponding to the respective partitioned resource unit.

[0122] For example, the user field corresponding to at least one resource unit among multiple segmented resource units used for data transmission may include the AID of the receiver or transmitter, and the user field corresponding to the remaining resource units not used for data transmission may include a pre-configured empty STA ID.

[0123] When a wireless communication device communicates using multiple links, its communication efficiency can be improved. In this case, a link can be a physical path and can consist of a wireless medium that can be used to deliver MAC Service Data Units (MSDUs). For example, if the frequency band of one link is used by another wireless communication device, the wireless communication device can continue to communicate through the other link. In this way, the wireless communication device can usefully utilize multiple channels. Furthermore, when a wireless communication device performs communication simultaneously using multiple links, the total throughput can be increased. However, in existing wireless LANs, it is already stipulated that one wireless communication device uses one link. Therefore, a WLAN operation method using multiple links is needed. This will be discussed later. Figures 9 to 25 This describes a wireless communication method for wireless communication devices using multiple links. First, it will be discussed through... Figure 9 Describe the specific form of a wireless communication device that uses multiple links.

[0124] Figure 9 The illustration shows a multi-link device according to an embodiment of the present disclosure.

[0125] A multi-link device (MLD) can be defined for wireless communication methods using the aforementioned multiple links. A multi-link device can represent a device with one or more affiliated stations. According to a specific embodiment, a multi-link device can represent a device with two or more affiliated stations. Additionally, a multi-link device can exchange multi-link elements. Multi-link elements include information about one or more stations or one or more links. Multi-link elements may include multi-link configuration elements, which will be described later. In this case, the multi-link device can be a logical entity. Specifically, a multi-link device can have multiple affiliated stations. A multi-link device can be referred to as a multi-link logical entity (MLLE) or a multi-link entity (MLE). A multi-link device can have a Media Access Control (MAC) Service Access Point (SAP) up to the Logical Link Control (LLC). An MLD can also have a MAC data service.

[0126] Multiple stations included in a multi-link device can operate on multiple links. Furthermore, multiple stations included in a multi-link device can operate on multiple channels. Specifically, multiple stations included in a multi-link device can operate on multiple different links or multiple different channels. For example, multiple stations included in a multi-link device can operate on multiple different channels in 2.4 GHz, 5 GHz, and 6 GHz.

[0127] The operation of a multi-link device can be referred to as multi-link operation, MLD operation, or multi-band operation. Additionally, when the station attached to the multi-link device is an Access Point (AP), the multi-link device can be called an AP MLD. Furthermore, when the station attached to the multi-link device is a non-AP station, the multi-link device can be called a non-AP MLD.

[0128] Figure 9 The diagram illustrates the operation of communication between non-AP MLD and AP-MLD. Specifically, non-AP MLD and AP-MLD communicate using three links respectively. AP MLD includes a first AP AP1, a second AP AP2, and a third AP AP3. Non-AP MLD includes a first non-AP STA (non-AP STA1), a second non-AP STA (non-AP STA2), and a third non-AP STA (non-AP STA3). AP1 and the first non-AP STA (non-AP STA1) communicate via the first link, Link1. The second AP AP2 and the second non-AP STA (non-AP STA2) communicate via the second link, Link2. The third AP AP3 and the third non-AP STA (non-AP STA3) communicate via the third link, Link3.

[0129] Multilink operation may include multilink setup operations. Multilink setup may correspond to the associated operations of the single-link operation described above, and may be performed first in a multilink setup for frame switching. The multilink device can obtain the information required for multilink setup from the multilink setup element. Specifically, the multilink setup element may include capability information associated with the multilink. In this case, the capability information may include information indicating whether any one of the multiple devices included in the multilink device performs a transmission and while another device can perform a reception. Additionally, the capability information may include information about the links available for each station included in the MLD. Furthermore, the capability information may include information about the channels available for each station included in the MLD.

[0130] Multi-link configuration can be set up through negotiation between peer stations. Specifically, multi-link configuration can be performed through communication between stations without communicating with the AP. Alternatively, multi-link configuration can be performed using any single link. For example, even if multiple links are configured from the first to the third link, the multi-link configuration can still be performed using the first link.

[0131] Additionally, a mapping between Service Identifiers (TIDs) and links can be configured. Specifically, frames corresponding to a specific TID value can be interchanged only through pre-specified links. The mapping between TIDs and links can be set based on direction. For example, when multiple links are configured between a first multi-link device and a second multi-link device, the first multi-link device can be configured to send frames with the first TID to multiple first links, while the second multi-link device can be configured to send frames with the second TID to the first links. Furthermore, default settings for the mapping between TIDs and links can exist. Specifically, in a multi-link configuration without additional settings, the multi-link devices can exchange frames corresponding to the TID at each link according to the default settings. In this case, the default setting could be to exchange all TIDs on any one link.

[0132] TIDs will be described in detail. A TID is an ID used to classify services and data to support Quality of Service (QoS). Additionally, TIDs can be used or assigned at layers higher than the MAC layer. Furthermore, a TID can indicate a Service Class (TC) or Service Flow (TS). Moreover, TIDs can be classified into 16 types. For example, a TID can be specified as one of the values ​​in the range of 0 to 15. The TID value to be used can be specified differently depending on the access policy and channel access or media access method. For example, in the case of using Enhanced Distributed Channel Access (EDCA) or Hybrid Coordination Function Contention-Based Channel Access (HCAF), a value in the range of 0 to 7 can be assigned to the TID. In the case of using EDCA, a TID can indicate User Priority (UP). In this example, UP can be specified based on TC or TS. UPs can be assigned at layers higher than the MAC layer. Additionally, in the case of using HCF Controlled Channel Access (HCCA) or SPCA, a value in the range of 8 to 15 can be assigned to the TID. In the case of using HCCA or SPCA, a TID can indicate a TSID. Additionally, when using HEMM or SEMM, a value in the range of 8 to 15 can be assigned to TID. When using HEMM or SEMM, TID can also indicate TSID.

[0133] UP and AC can be mapped. AC can be a label used to provide QoS in EDCA. AC can also be a label used to indicate a set of EDCA parameters. EDCA parameters or a set of EDCA parameters can be parameters used for EDCA channel contention. QoS stations can use AC to guarantee QoS. Additionally, AC can include AC_BK, AC_BE, AC_VI, and AC_VO. AC_BK, AC_BE, AC_VI, and AC_VO can respectively indicate background, best-effort, video, and voice. Furthermore, each of AC_BK, AC_BE, AC_VI, and AC_VO can be classified as a subordinate AC. For example, AC_VI can be subdivided into AC_VI primary and AC_VI standby. Similarly, AC_VO can be subdivided into AC_VO primary and AC_VO standby. Additionally, UP or TID can be mapped to AC. For example, UP or TID with values ​​1, 2, 0, 3, 4, 5, 6, and 7 can be mapped to AC_BK, AC_BK, AC_BE, AC_BE, AC_VI, AC_VI, AC_VO, and AC_VO, respectively. Additionally, UP or TID values ​​1, 2, 0, 3, 4, 5, 6, and 7 can be mapped to AC_BK, AC_BK, AC_BE, AC_BE, AC_VI (standby), AC_VI (primary), AC_VO (primary), and AC_VO (standby), respectively. Furthermore, UP or TID values ​​1, 2, 0, 3, 4, 5, 6, and 7 can sequentially have high priority. That is, 1 represents low priority, and 7 represents high priority. Therefore, AC_BK, AC_BE, AC_VI, and AC_VO can sequentially have high priority. Additionally, AC_BK, AC_BE, AC_VI, and AC_VO can correspond to AC indices (ACI) 0, 1, 2, and 3, respectively. Due to these characteristics of TIDs, the mapping between TIDs and links can indicate the mapping between ACs and links. Furthermore, the mapping between links and ACs can indicate the mapping between TIDs and links.

[0134] As described above, a TID can be mapped to each of multiple links. The mapping can specify the links capable of exchanging services corresponding to a predetermined TID or AC. Additionally, it can specify the TIDs or ACs that can be sent for each transmission direction within the link. As mentioned above, a default configuration for mapping between TIDs and links can exist. Specifically, in the absence of additional configuration for a multi-link configuration, the multi-link device can exchange frames corresponding to TIDs on each link according to the default configuration. In this example, the default configuration can exchange all TIDs on any one link. Any TID or AC at any given time can always be mapped to at least one link. Management and control frames can be sent on all links.

[0135] When a link is mapped to a TID or AC, only data frames corresponding to the TID or AC mapped to that link can be sent on that link. Therefore, when a link is mapped to a TID or AC, frames that do not correspond to the TID or AC mapped to that link cannot be sent on that link. When a link is mapped to a TID or AC, ACKs can also be sent based on the link to which the TID or AC is mapped. For example, a block ACK protocol can be determined based on the mapping between the TID and the link. According to another embodiment, the mapping between the TID and the link can be determined based on the block ACK protocol. In particular, a block ACK protocol can be set for TIDs mapped to predetermined links.

[0136] QoS can be guaranteed through the mapping between TIDs and links described above. Specifically, high-priority ACs or TIDs can be mapped to links with relatively few station operations or links with good channel conditions. In addition, the mapping between TIDs and links described above allows stations to maintain a power-saving state over long periods of time.

[0137] Figure 10 This is a diagram illustrating the simultaneous execution of transmissions in different links during multi-link operation according to an embodiment of the present disclosure.

[0138] Depending on the implementation of a multi-link device, it can simultaneously perform transmission on multiple links, simultaneously perform reception on multiple links, or perform transmission on any one link and may not simultaneously support reception on another link. This is because reception or transmission performed on any one link may affect reception or transmission performed on another link. Specifically, transmission on one link may act as interference on another link. Interference from one link of a single multi-link device that is applied to another link can be called internal leakage. Internal leakage can be high when the frequency interval between links is small. When transmission is performed on any one link, transmission on another link is possible if the amount of internal leakage is not too high. When transmission is performed on any one link, transmission on another link is not possible if the amount of internal leakage is too high. As mentioned above, the situation where a multi-link device performs transmission on multiple links simultaneously, a multi-link device performs transmission on any one link and simultaneously performs reception on another link, or a multi-link device performs reception on multiple links simultaneously can be called STR (simultaneous transmission and reception). As mentioned above, multi-link devices may not support STR. According to another detailed embodiment, the multi-link device may support STR in a limited manner. Specifically, the multi-link device may support STR only under predetermined conditions. For example, if the multi-link device operates using a single radio, it may not be able to perform STR. Additionally, if the multi-link device operates using a single antenna, it may not be able to perform STR. Furthermore, if the amount of internal leakage is detected to be greater than or equal to a predetermined value, the multi-link device may not be able to perform STR.

[0139] A station can exchange information with another station related to its STR capabilities. Specifically, a station can exchange information with another station related to whether its ability to perform transmission or reception across multiple links is limited. Specifically, the information related to whether the ability to perform transmission or reception across multiple links is limited can indicate whether simultaneous transmission across multiple links, simultaneous reception across multiple links, or simultaneous transmission and reception across multiple links is possible. Additionally, the information related to whether the ability to perform transmission or reception across multiple links is limited can be information indicating each level. Specifically, the information related to whether the ability to perform transmission or reception across multiple links is limited can be information indicating the level of an internal leakage magnitude. According to a detailed embodiment, the information indicating the level of an internal leakage magnitude can be information indicating the level of interference caused by internal leakage. According to another detailed embodiment, it can be information indicating the level of frequency spacing between links that may affect internal leakage. Additionally, the information indicating the level of an internal leakage magnitude can be information indicating the relationship between internal leakage and frequency spacing between links for each level.

[0140] exist Figure 10 In this configuration, the first station (STA1) and the second station (STA2) can be attached to a single non-AP multi-link device. Additionally, the first AP (AP1) and the second AP (AP2) can be attached to a single non-AP multi-link device. A first link (Link1) can be established between the first AP (AP1) and the first station (STA1), and a second link (Link2) can be established between the second AP (AP2) and the second station (STA2). The non-AP multi-link device can perform STR (Transmission Streaming) in a restricted manner. When the second station (STA2) performs transmission in the second link (Link2), the reception performed by the first station (STA1) in the first link (Link1) may be interfered with. For example, the second station (STA2) can send first data (Data1) in the second link (Link2), and the first AP (AP1) sends a response (ACK) to the first station (STA1) for the first data (Data1). The second station (STA2) then sends second data (Data2) in the second link (Link2). In this scenario, the transmission time of the second data (Data2) and the transmission time of the response to the first data (Data1) (ACK for Data1) may overlap. In this example, interference from the first link (Link1) may occur due to transmission to the second station (STA2) in the second link (Link2). Therefore, the first station (STA1) may not receive the response to the first data (Data1) (ACK for Data1). Figure 10(a) illustrates a scenario where transmission begins simultaneously across multiple links. However, as... Figure 10 As shown in (b), the transmission can begin at different times in multiple links.

[0141] Specifically, a multi-link device can independently perform channel access, such as backoff, on multiple links. In this example, simultaneous transmission on multiple links can begin when the backoff counters on multiple links reach 0. According to another detailed embodiment, when the backoff counter of any link of the multi-link device reaches 0, the multi-link device can perform energy detection (ED) only on a link different from the corresponding link and can perform channel access. If no energy greater than or equal to a predetermined value is detected, the multi-link device can perform channel access on the link where energy detection was performed. Thus, the multi-link device can begin simultaneous transmission on multiple links. The threshold value used for energy detection can be lower than the threshold value used to determine whether to decrease the backoff counter. Furthermore, when determining whether to decrease the backoff counter, the station can detect any type of signal, including wireless LAN signals. Additionally, in the above energy detection, the station can detect any type of signal, including wireless LAN signals. Internal leakage may not be detectable via wireless LAN signals. In this example, the station can sense signals detected due to internal leakage via energy detection. Furthermore, as mentioned above, the threshold value used for energy detection can be lower than the threshold value used to determine whether to decrease the backoff counter. Therefore, even though a transmission is being performed on another link, a multi-link device can decrease the backoff counter on any one of the links, such as... Figure 10 (a) and Figure 10 As shown in (b).

[0142] Reference Figures 11 to 25 This describes an operational method when the STR (Structured String) of a multi-link device is restricted. However, embodiments of this disclosure can also be applied when the STR of a multi-link device is unrestricted.

[0143] refer to Figures 11 to 15 This will describe the scenario where multiple PPDUs are transmitted simultaneously or can be transmitted simultaneously on multiple links. Additionally, when STR is unavailable on multiple links transmitting multiple PPDUs, a reference can be applied. Figures 11 to 15 The described embodiment. In a multi-link device receiving multiple PPDUs, where transmission is performed on any one link but reception is not possible on another, refer to... Figures 11 to 15 The described embodiments may be applicable. In cases where a multi-link device transmitting multiple PPDUs performs transmission on one link but is unable to perform reception on another link, refer to... Figures 11 to 15 The described embodiments may be applicable.

[0144] Figure 11 This is a diagram illustrating the operation of a multi-link device simultaneously terminating transmissions in multiple links according to an embodiment of the present disclosure.

[0145] In cases where a multi-link device performs transmissions on multiple links, the multi-link device can terminate simultaneous transmission on multiple links. Specifically, the end time of PPDUs transmitted on multiple links can be the same. Furthermore, besides the case where multi-link devices start transmissions simultaneously on multiple links, this embodiment can also be applied to cases where transmissions do not start simultaneously. This operation can be used for multi-link devices that cannot perform transmission and reception simultaneously. For example, this can be an operation for situations where a multi-link device receiving multiple PPDUs cannot perform transmission and reception simultaneously. Alternatively, this can be an operation for situations where a multi-link device sending multiple PPDUs cannot perform transmission and reception simultaneously. Specifically, as... Figure 10 As shown in (a), this prevents the failure of ACK reception on another link while transmission is being performed on any one link. Therefore, if a multi-link device does not support reception on another link while transmission is being performed on any one link, the multi-link device can terminate simultaneous transmission on multiple links.

[0146] When a response frame is sent in one link in response to a transmission performed by a multi-link device, that multi-link device can prevent transmissions in other links from being performed. Specifically, based on whether the frame sent by the multi-link device requests an ACK, the multi-link device can determine the end time of transmissions in multiple links. Based on whether the frame sent by the multi-link device requests an ACK, the multi-link device can terminate simultaneous transmissions in multiple links. That is, based on whether a frame included in at least one of multiple PPDUs requests an ACK, simultaneous transmissions in multiple links can be terminated. Whether a frame requests an ACK can be determined according to the ACK policy. For example, if the ACK policy of a frame is "no ACK", the multi-link device can determine that the frame does not request an ACK. Additionally, if the frame type and subtype correspond to "action no ACK frame", the multi-link device can determine that the frame does not request an ACK. The ACK policy, as well as the frame type and subtype, can be indicated by the frame's MAC header. Figure 11 As shown in the embodiments, the frame requesting ACK can be a data frame. Specifically, the frame requesting ACK can be a QoS data frame. This is because information indicating the ACK policy can be included in the QoS data frame.

[0147] exist Figure 11In this embodiment, while transmission is performed on any link, the multi-link device may be unable to perform reception on the other link. The first station (STA1) and the second station (STA2) of the multi-link device can respectively transmit first data (Data1) and second data (Data2). The first station (STA1) and the second station (STA2) can simultaneously terminate the transmission of the first data (Data1) and the second data (Data2). Therefore, the response to the first data (Ack for Data1) and the response to the second data (Ack for Data2) can be sent simultaneously without internal leakage, and the multi-link device can simultaneously receive the response to the first data (Ack for Data1) and the response to the second data (ACK for Data2).

[0148] Figure 12 This diagram illustrates the operation of terminating transmission in any one of the links when a multi-link device performs transmissions in multiple links according to an embodiment of the present disclosure.

[0149] When a multi-link device begins transmission on another link or begins simultaneous transmission on multiple links while performing transmission on any one link, the multi-link device may not be permitted to terminate transmission on the other link after transmission on any one link has commenced. Therefore, the multi-link device may terminate transmission on another link earlier than or simultaneously with the termination of transmission on any one link. Specifically, when a multi-link device begins transmission on another link while performing transmission on any one link and does not expect a response frame for a frame transmitted on that other link, the multi-link device may terminate transmission on the other link before or simultaneously with transmission on any one link. In this example, the response frame may be an immediate response frame. An immediate response frame may correspond to a situation where the interval between the frame and the response frame falls within a predetermined time interval. In this example, the predetermined time interval may be SIFS. Additionally, situations where a response frame is not expected may include cases where a reference has already been made. Figure 11The description covers the scenario where no ACK is requested. Specifically, a frame requesting an immediate response can include a frame requesting ACK. Additionally, a frame requesting an immediate response can include a frame triggering uplink transmission. Furthermore, a frame requesting an immediate response can include a QoS data frame requesting an immediate response. Additionally, a frame requesting an immediate response can include a control frame requesting an immediate response. Additionally, a frame requesting an immediate response can include a management frame requesting an immediate response. Furthermore, a PPDU including a frame requesting an immediate response can be a case where at least one frame included in the PPDU requests an immediate response. A PPDU including a frame requesting an immediate response from a station can be a case where at least one frame included in the PPDU requests an immediate response from a station. When a multi-link device performs transmission of a response frame that does not expect from any link, it is permissible for the multi-link device to not terminate transmission on another link before terminating transmission on any other link. Therefore, when a multi-link device performs transmission of a response frame that does not expect from any link, the multi-link device can terminate transmission on another link after terminating transmission on any other link. In cases where a multi-link device performs a transmission of a frame that does not expect a response frame on one link and sends a frame requesting an immediate frame on another link, the multi-link device can be allowed to continue transmission on the other link before terminating transmission on the first link. In this example, the response frame can be an immediate response frame. Therefore, if the multi-link device sends multiple PPDUs that do not include frames requesting responses, or a single PPDU that simultaneously sends frames requesting responses and PPDUs requesting responses, the multi-link device can avoid terminating transmission of multiple PPDUs simultaneously. In this example, the multi-link device can send multiple PPDUs in such a way that the transmission end time of the PPDU containing only frames that do not request responses is no later than the transmission end time of the PPDU containing frames requesting responses.

[0150] exist Figure 12 In this embodiment, while transmission is performed on any link, the multi-link device may be unable to perform reception on the other link. The first station (STA1) and the second station (STA2) of the multi-link device can respectively transmit first data (Data1) and second data (Data2). When the first station (STA1) transmits first data (Data1) to the first AP (AP1), the second station (STA2) begins transmitting second data (Data2). The second data (Data2) may not request an ACK. The second station (STA2) terminates the transmission of the second data (Data2) before the first station (STA1) terminates. Therefore, when the first station (STA1) receives an ACK for the first data (Ack for Data1), the transmission of the second station (STA2) can proceed without interfering with the first station (STA1).

[0151] In addition, the above embodiments can be applied to situations where a multi-link device cannot perform reception on another link while transmission is being performed on any one link.

[0152] Figure 13 This is a diagram illustrating a multi-link device delaying a transmission in another link when a transmission is performed in either link, according to an embodiment of the present disclosure.

[0153] Multi-link devices may not perform simultaneous transmission across multiple links. Specifically, a multi-link device may perform transmission only on a single link among multiple links. For example, if a multi-link device performs transmission on any one link and cannot receive on another, it may be able to perform transmission only on one of the multiple links. In such embodiments, the multi-link device may defer transmission when performing channel access. The channel access described herein may be referred to as including [the categories already referenced]. Figure 6 The described backoff process pertains to channel access. Specifically, a multi-link device can postpone transmissions on all links except the single link where transmission is to be performed. For example, the multi-link device can perform a backoff process on all of these links. In this example, the multi-link device can perform transmission on the link whose backoff counter first reaches 0, and can reset the backoff counters on the remaining links. Alternatively, if the backoff counters on multiple links reach 0, the multi-link device can perform transmission on any of the multiple links. In this example, the multi-link device can randomly select any of the multiple links and perform transmission on the selected link. Additionally, the multi-link device can reset the backoff counters on the unselected links. Resetting means setting a value randomly selected by the multi-link device within the CW to the backoff counter. Furthermore, the multi-link device can reset the CW of links where transmission is not performed. Specifically, the multi-link device can set the CW of links where transmission is not performed to CWmin, where CWmin is the minimum value of the CW. This type of embodiment can be applied to situations where the multi-link device performs transmission on any one link and cannot perform reception on another link.

[0154] According to another detailed embodiment, the multi-link device can determine a method for performing channel access across multiple links based on whether it performs transmission on any one link and cannot perform reception on another link. Specifically, if the multi-link device performs transmission on any one link and cannot perform reception on another link, the multi-link device may not independently perform channel access across multiple links. Conversely, if the multi-link device performs transmission on any one link and can perform reception on another link, the multi-link device can independently perform channel access across multiple links.

[0155] like Figures 11 to 12 As described above, multi-link devices can control the length of PPDUs to meet constraints based on simultaneous performance conditions. In this example, if the multi-link device cannot control the PPDU length until the transmission time arrives, it can perform transmission on any of the multiple links. Furthermore, if the allowed transmission time on any link is shorter than the service that needs to be sent on that link, the multi-link device can postpone transmission on that link. For example, according to... Figure 11 and Figure 12 In one embodiment, the allowed transmission time in the link can be shorter than the service that needs to be sent in the corresponding link.

[0156] Figure 13 In this embodiment, the multi-link device can independently perform channel access, including backoff, in the first link (Link1) and the second link (Link2). The backoff counter of the first link (Link1) and the backoff counter of the second link (Link2) can both reach 0 simultaneously. In this example, the multi-link device can perform transmission only in the second link (Link2) and can reset the backoff counter of the first link (Link1).

[0157] In the above embodiments, the multi-link device resets the backoff counter when transmission is delayed. According to another detailed embodiment, when the multi-link device delays transmission, it can maintain the backoff counter value as is. This ensures fairness in transmission between links that might deteriorate due to delayed transmission.

[0158] Figure 14 This diagram illustrates the operation of terminating transmission in any one of the links when a multi-link device performs transmissions in multiple links according to an embodiment of the present disclosure.

[0159] In the case where a multi-link device performs transmissions across multiple links, as referenced... Figure 11 As described in the embodiments, the multi-link device can simultaneously terminate transmissions in multiple links. Specifically, the multi-link device can simultaneously terminate PPDU transmissions in multiple links. Simultaneous termination of multiple PPDU transmissions can be referred to as aligning (aligning) the ends of the PPDUs. Furthermore, if the difference in transmission end times between multiple PPDUs is less than or equal to a threshold, the ends of the multiple PPDUs are considered aligned. In this example, the threshold can be a predetermined value. Specifically, the threshold can be a value set based on SIFS. Alternatively, the threshold can be a value set based on SIFS and signal extension length. For example, the threshold can be a value obtained by dividing the sum of SIFS and signal extension length by 2. In this example, the threshold can be 8µs.

[0160] When a multi-link device transmits multiple PPDUs to another multi-link device across multiple links, the multi-link device can align the ends of the multiple PPDUs. In this case, the multi-link device can be referred to as a transmitter multi-link device, and the other multi-link device can be referred to as a receiver multi-link device. The transmitter or receiver multi-link device can be a multi-link device that does not support STR or only partially supports STR. A multi-link device that does not support STR or only partially supports STR can be referred to as a non-STR multi-link device. Conversely, a multi-link device that supports STR can be referred to as an STR multi-link device.

[0161] Receiver multilink devices can be non-STR multilink devices. When a transmitter multilink device sends multiple PPDUs to a non-STR multilink device across multiple links, the transmitter multilink device can align the ends of the multiple PPDUs. Non-AP multilink devices can also be non-STR multilink devices. Therefore, when an AP multilink device sends multiple PPDUs to a non-STR non-AP multilink device across multiple links, the AP multilink device can align the ends of the multiple PPDUs.

[0162] The transmitter multilink device can be a non-STR multilink device. When a non-STR multilink device transmits multiple PPDUs to a receiver multilink device across multiple links, the transmitter multilink device can align the ends of the multiple PPDUs. Therefore, when a non-STR, non-AP multilink device transmits multiple PPDUs to an AP multilink device across multiple links, the non-STR, non-AP multilink device can align the ends of the PPDUs.

[0163] In this type of embodiment, the transmission direction from the AP or AP multilink device to a non-AP STA or non-AP multilink device can be referred to as the downlink (DL). Conversely, the transmission direction from a non-AP STA or non-AP multilink device to the AP or AP multilink device can be referred to as the uplink (UL). Frames and PPDUs sent by the AP or AP multilink device to a non-AP STA or non-AP multilink device can be referred to as DL frames and DL PPDUs, respectively. Frames and PPDUs sent by a non-AP STA or non-AP multilink device to the AP or AP multilink device can be referred to as UL frames and UL PPDUs, respectively.

[0164] The above-described embodiment of aligning the ends of multiple PPDUs can be applied to cases where only at least one of the multiple PPDUs includes a frame requesting an immediate response.

[0165] In the above embodiments, multiple PPDUs can be transmitted to a single multi-link device across multiple links. Specifically, the receiver multi-link device can receive multiple PPDUs from multiple stations belonging to the single multi-link device across multiple links. For example, the receiver multi-link device can operate in a first link and a second link. The first station of the receiver multi-link device operates in the first link, and the second station of the receiver multi-link device operates in the second link. When a first PPDU is transmitted to the first station in the first link, a second PPDU is transmitted to the second station in the second link, and if each of the first and second PPDUs includes a frame requesting an immediate response, the ends of the first and second PPDUs can be aligned.

[0166] In the above embodiments, transmitting multiple PPDUs across multiple links can be done simultaneously. Furthermore, transmitting multiple PPDUs across multiple links can be done simultaneously at any point in time. Although the start times of the transmission of multiple PPDUs may differ, simultaneous transmission of multiple PPDUs can have simultaneous points in time when the PPDUs are sent. Similarly, although the end times of the transmission of multiple PPDUs may differ, simultaneous transmission of multiple PPDUs can have simultaneous points in time when the PPDUs are sent.

[0167] According to other detailed embodiments, when at least one of the multiple PPDUs transmitted across multiple links includes a frame with high priority, the multi-link device may not align the ends of the multiple PPDUs. In this example, the frame with high priority may be a frame with a priority higher than a predetermined priority. Alternatively, the frame with high priority may be a predetermined frame. Through the above, the multi-link device can improve the transmission efficiency of frames with high priority.

[0168] In the above embodiments, if only some PPDUs among a plurality of PPDUs meet predetermined conditions, the multi-link device may align the ends of some PPDUs that meet the predetermined conditions. When the multi-link device transmits multiple PPDUs, it may align the ends of the PPDUs that include frames requesting immediate responses. For example, if only two PPDUs among the plurality of PPDUs include frames requesting immediate responses, the multi-link device may align the ends of only these two PPDUs. In these embodiments, the multi-link device may not align the ends of PPDUs that do not include frames requesting immediate responses with the ends of the PPDUs that include frames requesting immediate responses. Specifically, the multi-link device may perform transmission in such a manner that the ends of PPDUs that do not include frames requesting immediate responses are no later than the ends of PPDUs that include frames requesting immediate responses.

[0169] exist Figure 14 In this embodiment, the AP multi-link device may include a first AP (AP1), a second AP (AP2), and a third AP (AP3). Alternatively, the non-AP multi-link device may include a first station (STA1), a second station (STA2), and a third station (STA3). Both the AP multi-link device and the non-AP multi-link device can be non-STR multi-link devices. Specifically, the non-AP multi-link device can be a non-STR multi-link device. The first AP (AP1), second AP (AP2), and third AP (AP3) can send a first PPDU (PPDU1), a second PPDU (PPDU2), and a third PPDU (PPDU3) to the first station (STA1), the second station (STA2), and the third station (STA3) respectively via the first link (Link1), the second link (Link2), and the third link (Link3). The first PPDU (PPDU1) may include first data (Data1) requesting an immediate response, and the second PPDU (PPDU2) may include second data (Data2) requesting an immediate response. The third PPDU (PPDU3) may only include third data (Data3) that does not request an immediate response. An AP multi-link device can align the end of the first PPDU (PPDU1) with the end of the second PPDU (PPDU2), but can choose not to align the end of the third PPDU (PPDU3) with the ends of the first PPDU (PPDU1) and the second PPDU (PPDU2). In this example, the end time of the third PPDU (PPDU3) can be the same as or earlier than the end times of the first PPDU (PPDU1) and the second PPDU (PPDU2).

[0170] Figure 15 This diagram illustrates the operation of terminating transmission in any one of the links first when a multi-link device performs transmissions in multiple links according to another embodiment of this disclosure.

[0171] In a transmitter multilink device that transmits multiple PPDUs to a receiver multilink device across multiple links, the transmitter multilink device can determine the transmission length of each of the multiple PPDUs based on whether each corresponding PPDU includes a frame requesting an immediate response. Specifically, the transmitter multilink device can determine that the end of transmission for a PPDU that does not include a frame requesting an immediate response can be performed simultaneously with or earlier than the end of transmission for a PPDU that does include a frame requesting an immediate response. Therefore, the transmitter multilink device can determine that the end of transmission for a PPDU that includes a frame requesting an immediate response can be performed simultaneously with or later than the end of transmission for a PPDU that does not include a frame requesting an immediate response. In this embodiment, the transmitter multilink device or the receiver multilink device can be a non-STR multilink device.

[0172] exist Figure 15 In this embodiment, the AP multi-link device may include a first AP (AP1) and a second AP (AP2). Alternatively, the non-AP multi-link device may include a first station (STA1) and a second station (STA2). Both the AP multi-link device and the non-AP multi-link device can be non-STR multi-link devices. Specifically, the non-AP multi-link device can be a non-STR multi-link device. The first AP (AP1) and the second AP (AP2) can send a first PPDU (PPDU1) and a second PPDU (PPDU2) to the first station (STA1) and the second station (STA2) respectively via a first link (Link1) and a second link (Link2). The first PPDU (PPDU1) may include first data (Data1) requesting an immediate response, and the second PPDU (PPDU2) may only include second data (Data2) not requesting an immediate response. In this example, the second data (Data2) may be an A-MPDU that only includes MPDUs not requesting an immediate response. Furthermore, the receiver of the first data (Data1) may be the first station (STA1), and the receiver of the second data (Data2) may be the second station (STA1). Additionally, the first PPDU (PPDU1) and the second PPDU (PPDU2) can be either a SU PPDU or a MU PPDU. The AP multi-link device can transmit the first PPDU (PPDU1) and the second PPDU (PPDU2) with the second PPDU (PPDU2) having the same or earlier transmission end time as the first PPDU (PPDU1). References can be applied. Figure 15 The described embodiments, regardless of the PPDU transmission start time. Specifically, as Figure 15 As shown in (a), the transmission of the first PPDU (PPDU1) can begin earlier than the transmission of the second PPDU (PPDU2). Additionally, as... Figure 15 As shown in (b), the transmission of the first PPDU (PPDU1) can begin later than the transmission of the second PPDU (PPDU2).

[0173] via Figures 10 to 15 The embodiments can overcome problems that may be caused by internal leaks.

[0174] The mapping between links and TIDs can be found in the reference. Figure 9 The configuration is shown in the described embodiment. In this example, reference will be made to... Figures 16 to 20 Describe the detailed operation methods of multi-link devices.

[0175] Figure 16 This is a diagram illustrating how a multi-link device operates using a mapping between links and TIDs according to an embodiment of the present disclosure.

[0176] In embodiments of this disclosure, although a mapping exists between TIDs and links, multi-link devices can transmit services without adhering to this mapping. Specifically, MPDUs corresponding to TIDs not mapped to any link can be transmitted via the respective links. For example, an aggregated MPDU (A-MPDU) transmitted in any link can be an aggregation of MPDUs corresponding to TIDs mapped to the corresponding link and MPDUs corresponding to TIDs not mapped to the corresponding links. Additionally, PPDUs transmitted in any link can include MPDUs corresponding to TIDs mapped to the corresponding links and MPDUs corresponding to TIDs not mapped to the corresponding links. The above describes exceptions to the mapping between TIDs and links.

[0177] Specifically, when applying a restriction on the transmission end time of any link, frames corresponding to TIDs not mapped to that link can be sent in the corresponding link. According to a detailed embodiment, in the case of multi-link device operation, the multi-link device can set the transmission end time of the second link based on the transmission end time of the first link. In this example, the multi-link device can send MPDUs corresponding to TIDs mapped to the second link and MPDUs corresponding to TIDs not mapped to the second link together. Furthermore, the multi-link device can compare the value of the TID not mapped to a link with the value of the TID mapped to a link, and based on the comparison result, can determine whether to send both MPDUs corresponding to the TID mapped to the second link and MPDUs corresponding to the TIDs not mapped to the second link together. For example, if the value of the TID not mapped to a link is greater than the value of the TID mapped to a link, the multi-link device can send both MPDUs corresponding to the TID mapped to the link and MPDUs corresponding to the TIDs not mapped to the second link together. According to another detailed embodiment, when the value of the TID not mapped to a link is less than the value of the TID mapped to a link, the multi-link devices can send together the MPDU corresponding to the TID mapped to the link and the MPDU corresponding to the TID not mapped to the second link.

[0178] According to another detailed embodiment, the multi-link device can compare the priority corresponding to a TID not mapped to a link with the priority corresponding to a TID mapped to a link, and based on the comparison result, can determine whether to send both the MPDU corresponding to the TID mapped to the link and the MPDU corresponding to the TID not mapped to the link together in the corresponding link. In this example, the priority can be a service category (TC) or an access type (AC).

[0179] AP multi-link devices can include a first AP (AP1) and a second AP (AP2). Additionally, non-AP multi-link devices can include a first station (STA1) and a second station (STA2). A first TID (TID 0) and a third TID (TID 2) can be mapped to the first link (Link1), and a second TID (TID 1) can be mapped to the second link (Link2). The non-AP multi-link device can transmit an MPDU corresponding to a third TID (TID 2) not mapped to the second link (Link2) in the second link (Link2). Specifically, the non-AP multi-link device can transmit a PPDU in the second link (Link2), which includes an MPDU mapped to the first TID (TID 0) mapped to the second link (Link2) and an MPDU corresponding to the third TID (TID 2) not mapped to the second link (Link2). In this example, the non-AP multi-link device meets predetermined conditions, thereby enabling it to transmit an MPDU corresponding to a third TID (TID 2) not mapped to the second link (Link2). Specifically, since the value of the third TID (TID2) is greater than the value of the second TID (TID1), a non-AP multi-link device can send an MPDU corresponding to the third TID (TID2) that is not mapped to the second link (Link2) in the second link (Link2). Furthermore, if the non-AP multi-link device aligns the transmission end in the first link with the transmission end in the second link, the traffic that needs to be sent in the second link (Link2) is insufficient. Therefore, the non-AP multi-link device can send an MPDU corresponding to the third TID (TID2) that is not mapped to the second link (Link2) in the second link (Link2).

[0180] When a multi-link device selects a link from among multiple links for transmission, the multi-link device can transmit frames on the selected link that correspond to TIDs not mapped to the selected link. Specifically, when a multi-link device selects a link from among multiple links for transmission, the multi-link device can transmit frames on the selected link that correspond to TIDs mapped to the unselected link among the multiple links. Specifically, this embodiment can be applied to reference... Figure 13 The described embodiments.

[0181] In these embodiments, the problem to be solved may be determining which links the multi-link device will transmit responses to frames corresponding to TIDs not mapped to a link. In the links transmitting frames corresponding to TIDs not mapped to a link, the multi-link device may transmit responses to the corresponding frames. In this example, the response to the corresponding frame may be an ACK. For example, Figure 16In these embodiments, the AP multi-link device can send an ACK associated with a frame corresponding to a first TID (TID 0) in the first link (Link 1), and can also send an ACK associated with a frame corresponding to a third TID (TID 2) in the first link (Link 1). For example, the AP multi-link device can send an ACK associated with a frame corresponding to a second TID (TID 1) in the second link (Link 2), and can also send an ACK associated with a frame corresponding to a third TID (TID 2) in the second link (Link 2). In these embodiments, the multi-link device sends responses to frames in the link where the frame is received, and therefore, the implementation complexity may be low.

[0182] According to another detailed embodiment, the multi-link device can send a response to the corresponding frame in the link to which the corresponding TID is mapped, which is the opposite of sending a frame corresponding to a TID not mapped to a link. In this example, the response to the corresponding frame can be an ACK. For example, Figure 16 In these embodiments, the AP multi-link device can send an ACK associated with a frame corresponding to a first TID (TID 0) and an ACK associated with a frame corresponding to a third TID (TID 2) in the first link (Link 1). Additionally, the AP multi-link device can send an ACK associated with a frame corresponding to a second TID (TID 1) in the second link (Link 2). In these embodiments, the multi-link device can send responses to frames corresponding to TIDs via links not mapped to the corresponding TIDs, thus reducing the processing burden of collecting responses sent across multiple links.

[0183] Already referenced Figure 16 This describes exceptional cases where transmissions are performed independently of the mapping between links and TIDs. (See reference...) Figure 17 and Figure 18 The exceptions to performing transmissions independent of the mapping between the link and the TID will be described again with reference to other detailed embodiments.

[0184] Figure 17 This is a diagram illustrating the operation of a station performing UL MU transmission according to an embodiment of the present disclosure. Figure 18 This is a diagram illustrating a multi-link device performing multi-TID aggregation according to an embodiment of the present disclosure.

[0185] As described above, when there are restrictions on transmission end time, the multi-link device can compare the priority corresponding to a TID not mapped to a link with the priority corresponding to a TID mapped to a link. In this example, the multi-link device can determine whether to send the MPDU corresponding to the TID not mapped to a link in the corresponding link based on the comparison result. Specifically, if the priority of the MPDU corresponding to the TID mapped to a link is higher than the priority of the MPDU corresponding to the TID not mapped to a link, the multi-link device can send the MPDU corresponding to the TID not mapped to a link in the corresponding link. For example, if the priority of the MPDU corresponding to the TID not mapped to a link is the highest, the multi-link device can send the MPDU corresponding to the TID not mapped to a link in the corresponding link.

[0186] According to another detailed embodiment, when the priority of the MPDU corresponding to a TID not mapped to a link is lower than the priority of the MPDU corresponding to a TID mapped to a link, the multi-link device can transmit the MPDU corresponding to the TID not mapped to a link in the corresponding link. For example, when the MPDU corresponding to the TID not mapped to a link has the lowest priority, the multi-link device can transmit the MPDU corresponding to the TID not mapped to a link in the corresponding link. Through the above, the multi-link device has the opportunity to transmit services with low priority that rarely have the opportunity to be transmitted.

[0187] A multi-link device is only permitted to send an MPDU corresponding to a TID not mapped to a link within a corresponding link if both the MPDU corresponding to the TID mapped to the link and the MPDU corresponding to the TID not mapped to the link are sent together. Specifically, the transmission of MPDUs corresponding to the TID mapped to the link and the MPDU corresponding to the TID not mapped to the link can be performed as follows: The aggregated MPDU (A-MPDU) sent in any link can be an aggregation of the MPDU corresponding to the TID mapped to the corresponding link and the MPDU corresponding to the TID not mapped to the corresponding link. Additionally, the PPDU sent in any link can include both the MPDU corresponding to the TID mapped to the corresponding link and the MPDU corresponding to the TID not mapped to the corresponding link.

[0188] These embodiments can be applied to UL MU transmission operations. First, refer to... Figure 17 Describe the UL MU transmission operation.

[0189] Multiple stations can send PPDUs simultaneously. This transmission, or the series of processes used for transmission, is called uplink (UL) multi-user (MU) operation or UL MU transmission. For UL MU transmission, operations that trigger transmissions at multiple stations can be performed in advance.

[0190] Additionally, in cases where multiple stations simultaneously transmit a single PPDU, the multiple stations can use trigger-based (TB) PPDUs. TB PPDUs can include the previously described HE TB PPDU and EHT TB PPDU. Furthermore, TB PPDUs can be PPDUs that support simultaneous transmission through multiple stations. Multiple stations can receive frames that trigger UL MU transmissions and can perform UL MU transmissions based on the received frames. The AP can send frames that trigger UL MU transmissions to multiple stations. Additionally, the frame that triggers UL MU transmissions can indicate the Resource Units (RUs) allocated to each of the multiple stations in the performed UL MU transmission. A station can transmit a TB PPDU via the RU allocated to that station. Furthermore, the frame that triggers UL MU transmissions can be a trigger frame or a frame including trigger information. Frames including trigger information can include trigger information in the MAC header. Specifically, frames including trigger information can include trigger information in the A control field. Specifically, the trigger information can be a Trigger Response Scheduling (TRS) control field. Additionally, UL MU transmissions can be transmitted via the aforementioned TB PPDUs. In addition, multiple stations can perform UL MU transmissions as an immediate response. That is, the interval between the PPDU that includes the frame that triggers the UL MU transmission and the PPDU that includes the UL MU transmission can be SIFS.

[0191] The frame that triggers the UL MU transmission may include information associated with the length of the PPDU including the UL MU transmission. For ease of description, the information associated with the length of the PPDU including the UL MU transmission may be referred to as response length information. The response length information may be the length of the PPDU including the UL MU transmission. Based on the response length information included in the frame that triggers the UL MU transmission, the station can determine the length of the PPDU including the UL MU transmission. Specifically, the response length information may indicate the value of the length field of the L-SIG field of the PPDU including the UL MU transmission. For example, based on the length field of the triggering frame, the station can determine the value of the length field of the L-SIG field of the TB PPDU. Furthermore, even if the station does not have sufficient traffic to generate a PPDU corresponding to the response length information, the station can determine the length of the TB PPDU based on the response length information. Specifically, the station can insert padding into the TB PPDU. For example, if the station has empty bits in the TB PPDU even after all traffic in the buffer has been inserted into the TB PPDU, the station can insert padding into the empty bits. Through the above, the station can satisfy the length of the TB PPDU indicated by the response length information. Additionally, the response length information can indicate the number of OFMD symbols included in the TB PPDU. Therefore, when a station performs a UL MU transmission, it can perform the transmission based on the length indicated by the frame that triggered the UL MU transmission. Furthermore, all stations performing UL MU transmissions can send TB PPDUs of the same length. Moreover, the response to a UL MU transmission can be an immediate response. Therefore, the interval between a UL MU transmission and a response to a UL MU transmission can be SIFS.

[0192] refer to Figure 17The AP sends a trigger frame to the first station (STA 1) and the second station (STA 2). Each of the first station (STA 1) and the second station (STA 2) can send a TB PPDU via the RU, wherein the allocation to each of the first station (STA 1) and the second station (STA 2) is indicated by the trigger frame. In this example, the length of the TB PPDU sent by each of the first station (STA 1) and the second station (STA 2) can be determined based on the response length information indicated by the trigger frame. The lengths of the TB PPDUs sent by the first station (STA 1) and the second station (STA 2) are equal. In addition, the first station (STA 1) and the second station (STA 2) can send TB PPDUs as an immediate response to the trigger frame. The AP can send an ACK associated with the frame included in the TB PPDU sent by each of the first station (STA 1) and the second station (STA 2). As described above, even when stations send TB PPDUs, a limitation on the transmission end time can be applied. In this example, an embodiment of an exception related to the mapping between the link and the TID can be applied. This will refer to Figure 18 Further detailed description.

[0193] When a station performs a UL MU transmission, it can send frames corresponding to the TIDs of links in which UL MU transmissions are not mapped. Specifically, when a station performs a UL MU transmission, it can send both frames mapped to the links in which UL MU transmissions are performed and frames corresponding to the TIDs of links not mapped to the corresponding links. Figure 18 In this example, the station sends a TB PPDU via the first link (Link1). In this instance, the uplink of the first link (Link1) can be mapped to AC_VI and AC_BE. In this instance, as... Figure 18 As shown in (b), a station can send a PDSU or a data frame corresponding to AC_VI and AC_BE, along with a padded TB PPDU. In this example, in these embodiments, transmission efficiency may degrade when the padded length is significantly long. Additionally, the station sending the trigger frame (e.g., the AP) cannot accurately identify the traffic stored in the buffers of each of the multiple stations performing ULMU transmissions; therefore, the length of the padded included in the TB PPDU may increase. Therefore, the station may additionally include another AC not mapped to the first link (Link1), i.e., a PSDU or data frame corresponding to AC_VO, such as... Figure 18 As shown in (c).

[0194] As described above, the priorities of TIDs mapped to a station link and those not mapped to a link can be compared, and based on the comparison result, it can be determined whether to send a frame corresponding to the TID not mapped to a link in the corresponding link. For example, in Figure 18 In (c), AC_VO can have a higher priority than AC_VI or AC_BE, which are ACs mapped to the first link (Link1). Additionally, as described above, the station may not send PPDUs containing only frames corresponding to TIDs not mapped to the link, but may instead send both frames corresponding to TIDs mapped to the link and frames corresponding to TIDs not mapped to the link. Although Figure 18 An embodiment of this disclosure is illustrated with reference to the AC diagram, but the above embodiments can also be applied to situations where a TID or TSID instead of an AC is mapped to a link.

[0195] Furthermore, the above embodiments can be applied in conjunction with multi-TID aggregation rules. Multi-TID aggregation rules determine which MPDUs corresponding to different TIDs should be aggregated within a single A-MPDU. Therefore, MPDUs aggregated according to multi-TID aggregation rules may not adhere to the mapping between links and TIDs. Specifically, when a station aggregates MPDUs according to multi-TID aggregation rules, the station can send MPDUs corresponding to TIDs not mapped to links in the corresponding links. Multi-TID aggregation rules can be as follows.

[0196] 1) The TXOP limit of the transmission sequence for which it performs multi-TID aggregation is greater than or equal to 0.

[0197] 2) The aggregated A-MPDU includes at least one of the frames or MPDUs of the master AC or the AC used to obtain the TXOP.

[0198] 3) The TID corresponding to the frame or MPDU aggregated in the A-MPDU is the primary AC or a TID with a higher priority than the primary AC.

[0199] 4) The length of the A-MPDU does not exceed the TXOP obtained by the main AC.

[0200] 5) The number of TIDs of frames or MPDUs aggregated in A-MPDU does not exceed the number of TIDs indicated by the multi-TID aggregation Rx support.

[0201] In another detailed embodiment, condition 3) for the described multi-TID aggregation rule can be replaced by condition 3-1).

[0202] 3) The TID corresponding to the frame or MPDU aggregated in the A-MPDU is the primary AC or a TID with a lower priority than the primary AC.

[0203] In another detailed embodiment, a station can transmit TIDs that are not mapped to a link in the corresponding link based on the PPDU format. Specifically, when a station transmits a DL MU PPDU, it can transmit a frame corresponding to a TID that is not mapped to a link in the corresponding link. In this example, the DL MU PPDU can be a DL HE MU PPDU or an EHT PPDU sent to multiple users. Furthermore, a station can transmit any frame corresponding to any TID that is not mapped to a link in the corresponding link.

[0204] Specifically, when a station sends a TB PPDU, the station can send a frame corresponding to a TID that is not mapped to the link in the corresponding link. In this example, the TB PPDU can be an HE TB PPDU or an EHT TB PPDU. In a detailed embodiment, if the preferred AC subfield of the triggering frame indicates a predetermined AC and even if the TID not mapped to the link has a priority higher than or equal to the predetermined AC, the station can use a TB PPDU to send a frame corresponding to the corresponding TID. In another detailed embodiment, if the preferred AC subfield of the triggering frame indicates a predetermined AC and even if the TID not mapped to the link has a priority lower than the predetermined AC, the station can use a TB PPDU to send a frame corresponding to the corresponding TID. This embodiment can be applied when there is no frame in the transmission buffer corresponding to a priority higher than the predetermined AC. Furthermore, as described above, within the allowed length of the TB PPDU, the station can use a TB PPDU to send a frame corresponding to a TID, even if the TID is not mapped to the link. In this example, the number of TIDs of the frames aggregated in the A-MPDU can be limited. Specifically, the TID aggregation limit subfield included in the trigger frame can indicate the maximum number of TIDs aggregated in the A-MPDU.

[0205] Figure 19 This is a diagram illustrating elements of information associated with the mapping between a link and a TID, according to an embodiment of the present disclosure.

[0206] The site can execute depending on whether it supports or allows it, as referenced. Figures 16 to 18The described embodiments are associated with signaling. In addition to the TID mapped to the link, receiving a frame corresponding to a TID may require the station to perform additional operations. Specifically, when a restriction on transmission end time is applied, the station may perform signaling associated with whether to support or allow frame transmission that does not follow the mapping between the link and the TID. If the information indicating whether to support or allow frame transmission that does not follow the mapping between the link and the TID indicates a first predetermined value, the corresponding information may indicate that the station supports or allows frame transmission that does not follow the mapping between the link and the TID if a restriction on transmission end time is applied.

[0207] When the information indicating whether frame transmission that does not follow the mapping between the link and the TID is supported or permitted indicates a second predetermined value, the corresponding information may indicate that the station does not support or permits frame transmission that does not follow the mapping between the link and the TID. Specifically, when the information indicating whether frame transmission that does not follow the mapping between the link and the TID is supported or permitted indicates a second predetermined value, the corresponding information may indicate that if a limitation on the transmission end time is applied, the station does not support or permit frame transmission that does not follow the mapping between the link and the TID.

[0208] Additionally, information indicating whether frame transmission that does not follow the mapping between the link and TID is supported or permitted can be used to indicate whether a station supports or permits transmission based on restrictions on transmission end time. In this example, permission indicates whether the corresponding transmission can be received.

[0209] Additionally, the station can execute signaling for the maximum number of TIDs that the station can aggregate in a single A-MPDU. In this example, the maximum number of TIDs that a single A-MPDU can aggregate can be greater than or equal to the maximum number indicated by the TID aggregation limit field of the trigger frame. Specifically, the station can execute signaling for the maximum number of TIDs that the station can additionally aggregate besides the TIDs mapped to the link. In another detailed embodiment, the station can execute signaling for the maximum number of TIDs that the station can aggregate, including the TIDs mapped to the link. In the above embodiments, if a limitation on the transmission end time is applied, the signaling can be the maximum number of TIDs that the station can aggregate. Furthermore, the station can execute signaling for the maximum number of TIDs that the station can receive.

[0210] In the above embodiments, capability elements or operational elements can be used for signaling. A station can use capability elements or operational elements to perform signaling regarding whether the station supports or allows frame transmissions that do not follow the mapping between links and TIDs. Additionally, a station can use capability elements or operational elements to perform signaling on the maximum number of TIDs that the station can aggregate. Capability elements may include EHT capability elements. Operational elements may include EHT operational elements.

[0211] Figure 19 (a) illustrates capability elements according to an embodiment of the present disclosure, and Figure 19 (b) An operational element according to another embodiment of this disclosure is illustrated. The multi-link multi-TID aggregation support subfield of the capability element can perform signaling to the AP regarding whether a non-AP station supports frame transmission that does not follow the mapping between links and TIDs. The TID quantity subfield of the capability element indicates the maximum number of TIDs that the station can aggregate. The multi-link multi-TID aggregation permission subfield of the operational element can indicate to non-AP stations whether the AP allows frame transmission that does not follow the mapping between links and TIDs. In addition, the TID quantity subfield of the capability element indicates the maximum number of TIDs that the AP can receive.

[0212] Signaling associated with support and signaling associated with permission can be included in the same type of element. Additionally, signaling indicating whether frame transmission that does not conform to the mapping between the link and the TID is supported, and signaling indicating whether frame transmission that does not conform to the mapping between the link and the TID is permitted, can be included in the same type of subfield of the same type of element. In this example, the information in the subfield of the element can vary depending on the role of the station sending the element. Specifically, depending on whether the element is sent by a non-AP station or an AP, the information in the subfield of the element can differ. For example, if a non-AP station sends the element, the subfield of the element can indicate whether frame transmission that does not conform to the mapping between the link and the TID is supported. Conversely, if an AP sends the element, the subfield of the element can indicate whether frame transmission that does not conform to the mapping between the link and the TID is permitted.

[0213] When applying restrictions on transmission end time, it can be determined whether frame transmission that does not conform to the mapping between links and TIDs is allowed for each PPDU format. If information indicating whether frame transmission that does not conform to the mapping between links and TIDs is allowed is included in the frame or PPDU, the corresponding information can be applied to the response to the corresponding frame or PPDU. If information indicating whether frame transmission that does not conform to the mapping between links and TIDs is allowed is included in the frame or PPDU, the corresponding information can be applied to the transmission timing (TXOP) including the corresponding frame or PPDU. The maximum number of TIDs that a station can aggregate can be determined for each PPDU format. If information indicating the maximum number of TIDs that a station can aggregate is included in the frame or PPDU, the corresponding information can be applied to the response to the corresponding frame or PPDU. If information indicating the maximum number of TIDs that a station can aggregate is included in the frame or PPDU, the corresponding information can be applied to the response to the corresponding frame or PPDU. If information indicating the maximum number of TIDs that a station can aggregate is included in the frame or PPDU, the corresponding information can be applied to the TXOP including the corresponding frame or PPDU.

[0214] Specifically, the frame that triggers UL MU transmission may include information indicating whether frame transmission that does not conform to the mapping between the link and the TID is permitted. When a station sends a response to a frame that triggers UL MU transmission, the station may determine whether to send a frame corresponding to a TID that is not mapped to a link based on the information indicating whether frame transmission that does not conform to the mapping between the link and the TID is permitted. In a detailed embodiment, the information indicating whether frame transmission that does not conform to the mapping between the link and the TID is permitted may be included in the common information field of the triggering frame. For example, the information indicating whether frame transmission that does not conform to the mapping between the link and the TID is permitted may be included in bit 64 (i.e., B63) of the common information field.

[0215] In another detailed embodiment, information indicating whether frame transmissions that do not conform to the mapping between links and TIDs are permitted can be included in subsequent bits of the reserved subfield of UL HE-SIG-A2. In another detailed embodiment, information indicating whether frame transmissions that do not conform to the mapping between links and TIDs are permitted can be included in bits preceding the trigger-related public information field. In another detailed embodiment, information indicating whether frame transmissions that do not conform to the mapping between links and TIDs are permitted can be included in the user information field of the trigger frame. Additionally, embodiments applying information indicating whether frame transmissions that do not conform to the mapping between links and TIDs are permitted can also be applied to information indicating the maximum number of TIDs a station can aggregate. The aforementioned public information field may include information commonly applied to TB PPDUs or all stations responding to the trigger frame. The user information field may include information applied to the transmitted TB PPDU or the station providing a response in the RU indicated by the user information field.

[0216] Figure 21 This is a diagram illustrating a station performing channel access in order to send a trigger frame according to an embodiment of the present disclosure.

[0217] In the event of transmission of a frame that triggers UL MU transmission, the station can perform the previously referenced... Figure 6 The channel access described. In this example, the AIFS can be determined based on the AC, TID, or the priority of the service the station wants to transmit. Specifically, the AIFS can be a value obtained by adding the SIFS to the product of AIFSN and the slot time. If the station expects to transmit a service with relatively high priority, the AIFS length may be relatively short. Conversely, if the station expects to transmit a service with relatively low priority, the AIFS length may be relatively long. When a station performs channel access to transmit a trigger frame, determining the AC, TID, or priority to be applied by the station can be important.

[0218] When a station performs channel access to transmit a trigger frame, the station can perform channel access based on the AC, TID, or priority corresponding to the frame transmitted in response to the trigger frame, and the mapping between the link and TID. Specifically, when a station performs channel access to transmit a trigger frame, the station can perform channel access based on the AC corresponding to the frame transmitted in response to the trigger frame, and the mapping between the link and TID. In this example, the mapping between the link and TID can be configured between the transmitter and receiver of the trigger frame. In a detailed embodiment, the mapping between the link and TID can be a mapping between the TID and the link in the direction from the receiver of the trigger frame to the transmitter of the trigger frame. When a station performs channel access to transmit a trigger frame, the station can apply the AC or TID defined in the mapping between the TID and the link in the direction from the receiver of the trigger frame to the transmitter of the trigger frame. When a station performs channel access to transmit a trigger frame, the station can choose not to apply the AC or TID not defined in the mapping between the TID and the link in the direction from the receiver of the trigger frame to the transmitter of the trigger frame. When a station performs channel access to transmit a trigger frame, the station can apply a TID or AC determined based on the mapping between the TID and the link in the direction from the receiver of the trigger frame to the transmitter of the trigger frame. Alternatively, if multiple receivers receive the trigger frame, the mapping between the link and the TID can be a mapping between the TID and the link in the direction from the multiple receivers to the transmitter. These embodiments can be applied to cases where the PPDU containing only the frame triggering the ULMU transmission only includes the frame triggering the ULMU transmission. Additionally, these embodiments can be applied to cases where the PPDU containing the frame triggering the ULMU transmission does not include QoS data frames.

[0219] Furthermore, the above embodiments can be applied to situations where each receiver of the PPDU including the frame triggering UL MU transmission is a multi-link device. Therefore, the above embodiments can be applied to situations where each receiver of the PPDU including the trigger frame is a station included in a multi-link device. When the receivers including the PPDU of the trigger frame include stations not included in a multi-link device, the stations can use any AC.

[0220] In addition, if the frame that triggers UL MU transmission does not specify a station and triggers random access, the station can perform channel access regardless of the mapping between the link and TID.

[0221] exist Figure 20In this configuration, the AP multi-link device includes a first AP (AP 1). Additionally, a first non-AP multi-link device (non-AP MLD 1) includes a first station (STA 1). Furthermore, a second non-AP multi-link device (non-AP MLD 2) includes a second station (STA 2). A first link (Link1) is configured between the first station (STA 1) and the first AP (AP 1). The first link (Link1) is also configured between the second station (STA 2) and the first AP (AP 1). The mapping between links and TIDs in the first link (Link1) is configured. AC_VI and AC_VO are mapped to the link from the first station (STA 1) to the first AP (AP 1). Furthermore, all TIDs are mapped to the link from the first AP (AP 1) to the first station (STA 1). The mapping between links and TIDs in the second link (Link2) is configured. AC_VO is mapped to the link from the second station (STA 2) to the first AP (AP 1). Furthermore, all TIDs are mapped to the link from the second AP (AP 2) to the first station (STA 1). Figure 20 In (b), when the first AP (AP 1) sends a trigger frame to the first station (STA 1) and the second station (STA 2), the first AP (AP 1) can perform channel access based on AC_VI and AC_VO. This is because AC_VI and AC_VO are mapped to the link from the first station (STA 1) to the first AP (AP 1), and AC_VO is mapped to the link from the second station (STA 2) to the first AP (AP 1). When the first AP (AP 1) sends a trigger frame to the first station (STA 1) and the third station (STA 3) that are not part of any multi-link device, the first AP (AP 1) can use any AC to perform channel access. When the first AP (AP 1) sends a trigger frame that triggers random access, the first AP (AP 1) can use any AC to perform channel access.

[0222] According to another detailed embodiment, when a station performs channel access to transmit a frame that triggers UL MU transmission, the station can perform channel access independently of the mapping between the link and the TID. In this example, the station can use any AC. In this example, the mapping between the link and the TID can be a mapping between the UL link and the TID. Alternatively, the mapping between the link and the TID can be a mapping between the TID and the link in the direction of transmitting the trigger frame.

[0223] As described above, when a station sends a TB PPDU, it can send frames corresponding to the TIDs of links not mapped to the corresponding links. If a station does not acquire a TXOP through a contention process, it can perform a transmission regardless of the mapping between links and TIDs. If a station acquires a TXOP through a contention process, it can perform a transmission based on the mapping between links and TIDs. For example, if a station does not acquire a TXOP through a contention process, it can send frames corresponding to the TIDs of links not mapped to the corresponding links. If a station acquires a TXOP through a contention process, it can send only frames corresponding to the TIDs of links mapped to the corresponding links.

[0224] Figure 21 This is a diagram illustrating the operation of a multi-link device performing transmission across multiple links according to an embodiment of the present disclosure.

[0225] For reference Figures 10 to 15 In the described embodiments, limitations on the transmission end time of multi-link transmissions can be applied. In detailed embodiments, the multi-link device can determine whether to apply limitations on the transmission end time based on the frequency intervals between the links. The degree of internal leakage may vary depending on the frequency interval. When the frequency intervals between the links fall within a predetermined frequency interval, the multi-link device can be limited to performing simultaneous transmission and reception on multiple links. Furthermore, when the frequency intervals between the links are greater than the predetermined frequency interval, the multi-link device is not limited to performing simultaneous transmission or simultaneous reception on multiple links.

[0226] Additionally, bandwidth restrictions can be applied to multi-link devices that perform restrictive STR execution or communicate with other multi-link devices that perform restrictive STR execution. Furthermore, under predetermined conditions, multi-link devices that perform restrictive STR execution or communicate with other multi-link devices that perform restrictive STR execution can use bandwidth narrower than a predetermined width.

[0227] exist Figure 21 In a multi-link system, a non-AP device can include a first station (STA1) and a second station (STA2). The first station (STA1) and the second station (STA2) can operate in the first link (Link1) and the second link (Link2), respectively. Non-AP multi-link devices can restrict STR (Signal Streaming) support. Specifically, the STR support of a non-AP multi-link device can be limited based on the link's bandwidth or channel location. Figure 21In the context of a non-AP multi-link device operating in channel P20 of the first link (Link1) and the channel of the second link, the non-AP multi-link device can execute STR. However, in the context of a non-AP multi-link device operating in channel S20 or S40 of the first link (Link1) and the channel of the second link, the non-AP multi-link device cannot execute STR.

[0228] As described above, a station performing a transmission associated with a non-AP multilink can use limited bandwidth to send PPDUs. Specifically, as mentioned above, a station performing a transmission associated with a non-AP multilink can use limited bandwidth to send PPDUs when the non-AP multilink device performs the transmission. Figure 21 In one embodiment, when the second station (STA 2) is performing a transmission, the first AP (AP 1) can use a channel other than channel S20 or channel S40 to perform a transmission to the second station (STA 2), which is a channel that the first station (STA 1) is restricted to using in the first link (Link 1).

[0229] The multi-link device can autonomously make decisions related to the use of the aforementioned restricted channels. In another detailed embodiment, the use of restricted channels can be specifically indicated. For example, a frame that triggers UL MU transmission can be assigned a restricted channel. Additionally, when using a corresponding channel, the multi-link device can perform signaling to determine whether the STR (Signal String) is available for each channel. For example, when each of channels P20, P40, and P80 is used, the multi-link device can perform signaling to determine whether the STR is available for each channel.

[0230] Figure 22 This is a diagram illustrating the operation of setting up a NAV by a multi-link device according to an embodiment of the present disclosure.

[0231] As mentioned above, transmission may fail due to internal leakage caused by simultaneously performing transmission and reception across multiple adjacent links. Figure 22In this scenario, a multi-link device is simultaneously receiving data via the first link and transmitting data via the second link. Due to the transmission on the second link, the multi-link device may experience reception failure on the first link. If a station operating on the second link determines that the channel is idle, the corresponding station can access that channel and perform transmission. A station operating on the first link (Link1) can set the Network Allocation Vector (NAV) based on PPDUs or frames transmitted on the first link (Link1). A station operating on the first link (Link1) can determine that the channel is busy due to NAV when another station is performing transmission on the first link (Link1). As described above, if frames or PPDUs transmitted on the first link can set the NAV on the second link, the probability of transmission failure due to internal leakage can be reduced. This will refer to... Figures 23 to 25 Describe it.

[0232] Figure 23 This is a diagram illustrating the operation of setting up a NAV by a multi-link device according to an embodiment of the present disclosure.

[0233] Multi-link devices can share duration information between links. In this example, the duration information can be the TXOP duration field of the signaling field of the PPDU. In this example, the signaling field can be the HE-SIG-A field. Alternatively, the signaling field can be the U-SIG field. Additionally, the duration information can be a value indicated by the duration / ID field of the MAC header. The TXOP duration field and the duration / ID field can indicate TXOP. In another detailed embodiment, the duration information can be a value indicated by the length field of the L-SIG field of the PPDU. The length field can indicate the length from the end of the L-SIG field to the end of the PPDU in a PPDU including the L-SIG field.

[0234] Based on shared duration information, multi-link devices can restrict channel access or transmission in each link. Specifically, based on shared duration information, multi-link devices can set the NAV for each station on each link. For example, stations included in the multi-link device can set the NAV based on frames or PPDUs sent to another station included in the multi-link device. In this example, the multi-link device can reset the NAV when performing channel access or transmission. In this example, the NAV can be an intra-BSS NAV. An intra-BSS NAV can be an NAV set by an intra-BSS frame or intra-BSS PPDU.

[0235] exist Figure 23In this multi-link configuration, a receiving device can perform reception on the first link. The duration information received on the first link can be transmitted to the second link, and a station operating on the second link can set a NAV based on the transmitted duration information. As mentioned above, a NAV is also set for a station operating on the second link; therefore, when transmission is performed on the first link, a station operating on the second link does not perform channel access or transmission.

[0236] In another detailed embodiment, multiple stations included in a multi-link device can use an inter-link NAV. Specifically, stations included in a multi-link device can perform channel access based on an inter-link NAV set based on PPDUs or frames exchanged by another station included in the same multi-link device. For example, when the multi-link device operates in a first link and a second link, a station operating in the second link can set an inter-link NAV based on PPDUs or frames sent in the first link. In this example, the corresponding station can choose not to perform transmission in the second link based on the set inter-link NAV value. Specifically, based on the set inter-link NAV value, the corresponding station can determine that the channel in the second link is busy. Additionally, multi-link devices that do not support STR can access the channel based on an inter-link NAV. In this example, a multi-link device that sets an inter-link NAV can determine whether to perform channel access or transmission in the multi-link device itself or in all links operated by the multi-link device based on the inter-link NAV.

[0237] Additionally, stations can access the channel based on a basic NAV and an intra-BSS NAV. The basic NAV can be an NAV set by an inter-BSS frame or an inter-BSS PPDU. Furthermore, if a station cannot determine whether a received frame is an inter-BSS frame or an intra-BSS frame, or if a station cannot determine whether a received PPDU is an inter-BSS PPDU or an intra-BSS PPDU, the station can set a basic NAV based on the received frame or PPDU.

[0238] When setting the inter-link NAV as described above, although the NAV set in association with transmission in another link is reset, the NAV value set in association with transmission in that link can be maintained as is. For example, when a multi-link device operates in both a first and a second link, the station operating in the second link can set the NAV based on PPDUs or frames transmitted in the second link. Subsequently, after the corresponding station sets the NAV based on PPDUs or frames transmitted in the first link, if the TXOP expires in the first link and the NAV is reset, the NAV set for transmission in the second link can also be reset. In the case of inter-link NAV operation, although the TXOP expires in the first link and the inter-link NAV is reset, the multi-link device can maintain the NAV set for transmission in the second link. Therefore, the multi-link device can reliably operate using inter-link NAV.

[0239] In the above embodiments, the operation of setting the NAV at a station can be replaced by the operation of suspending channel access or transmission in the physical layer. Alternatively, in the above embodiments, the operation of setting the NAV at a station can be replaced by the operation of determining that the channel is busy. In this example, the operation of resetting the NAV at a station can be replaced by the operation of performing channel access, performing transmission, or determining that the channel is idle. For this purpose, primitives exchanged between the physical layer and the MAC layer can be used. Specifically, primitives of the MAC layer of a single station connecting multiple link devices and the physical layer of another station in the corresponding multiple link device can be used. Alternatively, the MAC layer of a single station in the multiple link device and the MAC layer of another station in the corresponding multiple link device can be connected.

[0240] Furthermore, when a single station in a multi-link device begins receiving a PPDU, another station in the multi-link device can suspend channel access. As mentioned above, the other station can suspend channel access based on duration information. However, due to the location of the field including duration information, the suspension of channel access execution may be delayed. Therefore, since channel access is executed until the duration information is obtained, internal leakage may occur when transmission is performed. Therefore, as mentioned above, when a single station in a multi-link device begins receiving a PPDU, another station in the multi-link device can suspend channel access. Additionally, if the intended receiver of a PPDU received by any station or a frame included in the PPDU is not the corresponding station, the other station can resume the suspended channel access. This will refer to... Figure 24 Describe in detail.

[0241] Figure 24 This is a diagram illustrating a station of a multi-link device according to an embodiment of the present disclosure suspending channel access or transmission due to another station of the multi-link device receiving a PPDU and then resuming channel access or transmission.

[0242] As described above, a station in a multi-link device can suspend channel access or transmission if another station in the multi-link device receives a PPDU. In this example, if the receiver of the PPDU received by the other station, or the frame included in the PPDU, is different from that of the other station, the station can resume channel access or transmission. Specifically, if the other station fails to perform PPDU decoding, the station can resume channel access or transmission. In a detailed embodiment, if the other station obtains duration information from the L-SIG field of the PPDU, the station can continuously suspend channel access or transmission. If the station does not obtain duration information from the L-SIG field of the PPDU, the station can resume channel access or transmission. For example, if the station fails to decode the L-SIG field of the PPDU, the station can resume channel access or transmission. Additionally, if the other station fails to decode the U-SIG field or HE-SIG-A field of the PPDU, the station can resume channel access or transmission. In a detailed embodiment, if the other station obtains duration information from the U-SIG field or HE-SIG-A field of the PPDU, the station can continuously suspend channel access or transmission. Additionally, if the PHY identifier of the PPDU received by another station is in a PPDU format that the other station does not support, the station can restore channel access or transmission.

[0243] Additionally, if the BSS color of the PPDU received by another station does not indicate the BSS to which that station belongs, the station can resume channel access or transmission. If the BSS color of the PPDU received by another station indicates the BSS to which that station belongs, the station can continuously suspend channel access or transmission. If the station fails to obtain the BSS color from the U-SIG field or HE-SIG-A field of the PPDU, the station can resume channel access or transmission.

[0244] Additionally, if the intended receiver of a PPDU received at another station is not that other station, the station can resume channel access or transmission. If the intended receiver of a PPDU received at another station is that other station, the station can continuously suspend channel access or transmission. If the other station is the intended receiver of the received PPDU, at least one STA-ID included in the EHT-SIG or HE-SIG-B of the PPDU can indicate the other station. Specifically, if the other station is the intended receiver of the received PPDU, one of the STA-IDs included in the EHT-SIG or HE-SIG-B of the PPDU can indicate a group including the other station. For example, if one of the STA-IDs indicates a broadcast, the station can determine that the other station is the intended receiver of the received PPDU.

[0245] Additionally, if the intended receiver of a PPDU received by another station is not that other station, the station can restore channel access or transmission. In this example, if the station indicated by the RA or DA field in the MAC header is another station, the station can determine that the intended receiver of frames included in a PPDU received by that other station is that other station. If the RA or DA field in the MAC header indicates a group including another station, the station can determine that the intended receiver of frames included in a PPDU received by that other station is that other station. If the RA or DA field in the MAC header indicates a broadcast, the station can determine that the intended receiver of frames included in a PPDU received by that other station is that other station.

[0246] If the intended receiver of a frame included in a PPDU received at another station is another station, the station can continuously suspend channel access or transmission.

[0247] In the above embodiments, if a station continuously suspends channel access or transmission, it can suspend channel access or transmission until the end of the PPDU received by another station. In this embodiment, the station can quickly resume transmission. In another detailed embodiment, if a station continuously suspends channel access or transmission, it can suspend channel access or transmission until the TXOP duration. In this embodiment, the station more reliably protects the frame exchange sequence performed in another link. In this example, the TXOP duration can be obtained from the duration / ID field of the MAC header or the signaling field of the PPDU.

[0248] When another station receives a PPDU and sequentially decodes the signaling fields of the received PPDU, the aforementioned suspension / resumption of channel access or transmission can be applied. In this example, the decoding sequence can be determined based on the PPDU format and frame format. For example, if the received PPDU is as follows... Figure 24 In the case of the EHT PPDU shown, another station can sequentially decode the L-SIG, U-SIG, EHT-SIG, and MAC headers. Additionally, in the case of a HE SU PPDU or HE TB PPDU, another station can sequentially decode the L-SIG, HE-SIG-A, and MAC headers. Furthermore, in the case of a HE MUPPDU, another station can sequentially decode the L-SIG, HE-SIG-A, HE-SIG-B, and MAC headers. Finally, in the case of an 11a / g PPDU, another station can sequentially decode the L-SIG and MAC headers.

[0249] The intended receiver of the aforementioned PPDU or frame can be the intended receiver of the RU in which the PPDU was sent. Alternatively, the identifier used to determine whether a receiver is an intended receiver can be a value determined based on the station's AID or MAC address. Furthermore, the identifier used to determine whether a receiver is an intended receiver can be an identifier indicating a single station.

[0250] Figure 25 This is a diagram illustrating a method by which a multi-link device sends a response to a trigger frame when the NAV is configured for use with a multi-link device and a trigger frame is received, according to an embodiment of the present disclosure.

[0251] When a station sends a response to a frame that triggers UL MU transmission, the station may disregard the intra-BSS NAV and the aforementioned inter-link NAV. Specifically, when a station sends a response to a frame that triggers UL MU transmission from its own BSS, the station may disregard the intra-BSS NAV and the aforementioned inter-link NAV. When a station sends a response to a frame that triggers UL MU transmission from a multi-link device that includes stations within its own BSS, the station may disregard the intra-BSS NAV and the aforementioned inter-link NAV. In this example, the station may be an AP.

[0252] When a station receives a trigger frame from a multi-link device of a station that sends a frame setting the current intra-BSS NAV or inter-link NAV, and the station sends a response to the trigger frame, the station may disregard the intra-BSS NAV and inter-link NAV. Similarly, when a station receives a trigger frame from a station that sends a frame setting the current intra-BSS NAV or inter-link NAV, and the station sends a response to the trigger frame, the station may disregard the intra-BSS NAV and inter-link NAV.

[0253] In the above embodiments, the fact that the station does not consider NAV means that although NAV is set, the station ignores NAV, determines that virtual carrier sensing is idle, or determines not to perform virtual carrier sensing.

[0254] In these embodiments, although the AP multilink device sets NAV for non-AP multilink devices, the AP multilink device can trigger transmissions performed by non-AP multilink devices. Therefore, the AP multilink device can improve network efficiency.

[0255] exist Figure 25In this embodiment, the non-AP multilink device may include a first station (STA1) and a second station (STA2). The first station (STA1) and the second station (STA2) may operate in the first link (Link1) and the second link (Link2), respectively. The second station (STA2) sets its NAV based on frames or PPDUs sent to the first station (STA1). In this example, if the second station (STA2) receives a trigger frame that triggers the second station (STA2) from an AP associated with the second station (STA2) or an AP included in a multilink device that includes an AP associated with the second station (STA2), the second station (STA2) may send a response to the trigger frame without considering the NAV set for the second station (STA2).

[0256] Although this disclosure has been described above using WLAN communication as an example, it is not limited thereto and can be equivalently applied to other communication systems such as cellular communication. Furthermore, while the methods, apparatus, and systems of this disclosure have been described in conjunction with certain embodiments, some or all of the components and operations of this disclosure can be implemented using a computer system with a general-purpose hardware architecture.

[0257] The features, structures, effects, etc., described in the above embodiments are included in at least one embodiment of this disclosure, and are not necessarily limited to one embodiment. Furthermore, those skilled in the art to which the embodiments pertain can combine or modify the features, structures, effects, etc., shown in each embodiment for other embodiments. Therefore, content related to these combinations and modifications should be interpreted as falling within the scope of this disclosure.

[0258] Although the embodiments have been described above in detail, they are merely examples and not limiting of this disclosure, and those skilled in the art will recognize that various modifications and applications not illustrated above are possible without departing from the essential characteristics of these embodiments. For example, each component specifically shown in the embodiments is a component that can be modified and implemented. Furthermore, differences associated with these modifications and applications should be interpreted as falling within the scope of this disclosure as defined in the appended claims.

Claims

1. A non-access point (AP) multi-link device using multiple links, the non-AP multi-link device comprising: transceiver; as well as processor, The processor is configured as follows: A channel access method is used to access a channel in the plurality of links. This channel access method uses a backoff counter, wherein the initial value of the backoff counter is set by a random number obtained within a contention window; the backoff counter is decremented by 1 when the accessed channel is idle during the time slot period; and when the value of the backoff counter is 0, the station is allowed to perform transmission in the channel. Even if the backoff counter reaches 0 in channel access on any of the plurality of links, no transmission is performed on any of the links, the backoff counter is kept at 0, and the contention window size is maintained, wherein if the AP multi-link device performs transmission on another link, the reception by the non-AP multi-link device on one of the plurality of links is limited due to internal leakage from the other of the plurality of links.

2. The non-AP multi-link device according to claim 1, wherein, The processor is further configured to enable the non-AP multilink device to simultaneously receive multiple PPDUs from the AP multilink device on the multiple links using the transceiver. Among these, the ends of the multiple PPDUs requesting immediate responses are aligned, and Specifically, the ends of PPDUs that only include frames that do not request an immediate response are not aligned with the ends of PPDUs that include frames that request an immediate response.

3. The non-AP multi-link device according to claim 2, wherein, The ACK strategy is used to determine whether a frame requesting an immediate response is a frame requesting an ACK.

4. A method for operating a non-access point (AP) multilink device using multiple links, the method comprising: A channel access method is used to access a channel in the plurality of links. This channel access method uses a backoff counter, wherein the initial value of the backoff counter is set by a random number obtained within a contention window; the backoff counter is decremented by 1 when the accessed channel is idle during the time slot period; and when the value of the backoff counter is 0, the station is allowed to perform transmission in the channel. Even if the backoff counter reaches 0 in channel access on any of the plurality of links, no transmission is performed on any of those links; the backoff counter is kept at 0, and the size of the contention window is maintained. If the AP multilink device performs a transmission in another link, the reception by the non-AP multilink device in one of the multiple links is limited due to internal leakage from the other link.

5. The method according to claim 4, wherein, The method further includes enabling the non-AP multi-link device to simultaneously receive multiple PPDUs from the AP multi-link device on the multiple links using the transceiver. Among these, the ends of the multiple PPDUs requesting immediate responses are aligned, and Specifically, the ends of PPDUs that only include frames that do not request an immediate response are not aligned with the ends of PPDUs that include frames that request an immediate response.

6. The method according to claim 5, wherein, The ACK strategy is used to determine whether a frame requesting an immediate response is a frame requesting an ACK.

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