KR20240054187A - Method and apparatus for schedulingdirect communication in wireless local area network - Google Patents

Abstract

A method and apparatus for scheduling direct communication in a wireless LAN are disclosed. The STA MLD method includes transmitting a first frame requesting use of a link for direct communication to the AP MLD on a first link, and sending a second frame to the first frame in response to the request for use of the link for direct communication. Receiving from the AP MLD on a link, and performing the direct communication at a TWT SP of a second link established by an exchange procedure of the first frame and the second frame.

Description

Method and apparatus for scheduling direct communication in wireless LAN {METHOD AND APPARATUS FOR SCHEDULINGDIRECT COMMUNICATION IN WIRELESS LOCAL AREA NETWORK}

This disclosure relates to wireless LAN (Wireless Local Area Network) communication technology, and more specifically, to scheduling technology for direct communication in a wireless LAN supporting multiple links.

Recently, as the spread of mobile devices has expanded, wireless LAN (Wireless Local Area Network) technology, which can provide fast wireless communication services to mobile devices, has been receiving a lot of attention. Wireless LAN technology may be a technology that allows mobile devices such as smart phones, smart pads, laptop computers, portable multimedia players, embedded devices, etc. to wirelessly access the Internet based on wireless communication technology in a short distance.

As applications requiring higher throughput and real-time transmission arise, the IEEE 802.11be standard, an Extreme High Throughput (EHT) wireless LAN technology, is being developed. The goal of the IEEE 802.11be standard may be to support throughput rates as high as 30 Gbps. The IEEE 802.11be standard can support techniques to reduce transmission delay. In addition, the IEEE 802.11be standard provides expanded frequency bandwidth (e.g., 320 MHz bandwidth), multi-link transmission and aggregation operations, including operations using multi-bands, It may support multiple Access Point (AP) transmission operations and/or efficient retransmission operations (e.g., Hybrid Automatic Repeat Request (HARQ) operations).

However, since multi-link operation is an operation not defined in the existing wireless LAN standard, detailed operation definition may be necessary depending on the environment in which the multi-link operation is performed. In particular, devices that support enhanced multi-link single radio (EMLSR) operation (e.g., station (STA), access point (AP), multi-link device (MLD)) can wait for reception on multiple links. . A device that supports EMLSR operation may be referred to as an EMLSR device.

If the EMLSR device starts transmitting and receiving frames on a single link, the EMLSR device can operate only on the single link. In other words, the EMLSR device cannot perform frame transmission and reception operations on another link while performing frame transmission and reception operations on a single link. Interference may occur between multiple links. Transmissions on one link may cause interference on the other link(s). Due to the interference, additional detailed operations may be required for communication over multiple links. Depending on the additional detailed operations, definition of operations for direct communication in multiple links and/or scheduling of direct communication may be necessary.

Meanwhile, the technology behind the invention was written to improve understanding of the background of the invention, and may include content that is not prior art already known to those skilled in the art in the field to which this technology belongs.

The purpose of the present disclosure to solve the above problems is to provide a method and device for scheduling direct communication in a wireless LAN supporting multiple links.

The STA MLD method according to embodiments of the present disclosure for achieving the above purpose includes transmitting a first frame requesting use of a link for direct communication to the AP MLD on a first link, the link for direct communication receiving a second frame from the AP MLD on the first link in response to a request for use, and the direct TWT SP on the second link established by an exchange procedure of the first frame and the second frame. It includes performing communication.

The first frame may include information on at least one of the second link or the TWT SP with which the STA MLD wishes to perform the direct communication.

The second frame may include information on at least one of the second link or the TWT SP for which direct communication of the STA MLD is permitted.

The method of the STA MLD may further include performing communication with the AP MLD at a TXOP in one of the first link and the second link, prior to the TWT SP, and the first link And when the second link is an NSTR link pair, the TXOP may be set to end before the MediumSyncDelay time from the start of the TWT SP, or the TXOP may be terminated early before the MediumSyncDelay time from the start of the TWT SP.

The method of the STA MLD may further include performing communication with the AP MLD at a TXOP within one of the first link and the second link, prior to the TWT SP, and "the first If the link and the second link are an NSTR link pair and the STA MLD is an EMLSR MLD, the TXOP is set to end before “MediumSyncDelay time + EMLSR transition time” from the start of the TWT SP, or the TXOP is set to It can be terminated early before “MediumSyncDelay time + EMLSR transition time” from the start of TWT SP.

During the time corresponding to the TWT SP of the second link, the STA MLD may not expect to receive a frame from the AP MLD on the first link that is the second link and NSTR link pair.

If the first link and the second link are an NSTR link pair, the TWT SP may be configured to include a MediumSyncDelay time, and the direct communication may be performed in the time remaining after the end of the MediumSyncDelay time within the TWT SP. there is.

“If the first link and the second link are an NSTR link pair, and the TWT SP partially overlaps with the MediumSyncDelay time,” the direct communication is “a time that does not overlap with the MediumSyncDelay time within the TWT SP + the AP MLD may be carried out in “additional time allotted by”.

The method of the STA MLD further includes transmitting a third frame for early termination of the TWT SP when the direct communication is terminated, and early termination of the TWT SP after transmission of the third frame. can do.

The AP MLD method according to embodiments of the present disclosure for achieving the above purpose includes receiving a first frame requesting use of a link for direct communication from the STA MLD on a first link, the first frame including: determining a second link and a TWT SP on which the direct communication is performed based on the information provided, and sending a second frame including information of the second link and information of the TWT SP to the STA MLD in the first link. During the time corresponding to the TWT SP of the second link, the AP MLD does not communicate with the STA MLD on the first link that is the second link and the NSTR link pair.

The method of the AP MLD may further include performing communication with the STA MLD at a TXOP within one of the first link and the second link, prior to the TWT SP,

The TXOP may be set to end before the MediumSyncDelay time from the start of the TWT SP, or the TXOP may be terminated early before the MediumSyncDelay time from the start of the TWT SP.

The method of the AP MLD may further include performing communication with the STA MLD at a TXOP within one of the first link and the second link, prior to the TWT SP, where the STA MLD In the case of EMLSR MLD, the TXOP is set to terminate before “MediumSyncDelay time + EMLSR transition time” from the start of the TWT SP, or the TXOP is terminated early before “MediumSyncDelay time + EMLSR transition time” from the start of the TWT SP It can be.

The method of the AP MLD may further include allocating additional time to the STA MLD when “the first link and the second link are an NSTR link pair and the TWT SP overlaps the MediumSyncDelay time”. In addition, the direct communication of the STA MLD may be performed in “a time that does not overlap with the MediumSyncDelay time within the TWT SP + additional time allocated by the AP MLD.”

The AP MLD method may further include receiving a third frame for early termination of the TWT SP from the STA MLD, and early termination of the TWT SP after receiving the third frame.

The STA MLD according to embodiments of the present disclosure for achieving the above purpose includes at least one processor, wherein the STA MLD sends a first frame requesting use of a link for direct communication. transmit to an AP MLD on a first link, receive a second frame from the AP MLD on the first link in response to a request to use the link for direct communication, and exchange the first frame with the second frame. Causes the TWT SP of the second link established by the procedure to perform the direct communication.

The at least one processor may further cause the STA MLD to perform communication with the AP MLD at a TXOP within one of the first link and the second link, prior to the TWT SP, and If link 1 and the second link are an NSTR link pair, the TXOP may be set to end before MediumSyncDelay time from the start of the TWT SP, or the TXOP may be terminated early before the MediumSyncDelay time from the start of the TWT SP.

The at least one processor may further cause the STA MLD to perform communication with the AP MLD at a TXOP within one of the first link and the second link, prior to the TWT SP, and "the “If the first link and the second link are an NSTR link pair, and the STA MLD is an EMLSR MLD,” the TXOP is set to end before “MediumSyncDelay time + EMLSR transition time” from the start of the TWT SP, or the TXOP may be terminated early before “MediumSyncDelay time + EMLSR transition time” from the start of the TWT SP.

If the first link and the second link are an NSTR link pair, the TWT SP may be configured to include a MediumSyncDelay time, and the direct communication may be performed in the time remaining after the end of the MediumSyncDelay time within the TWT SP. there is.

“If the first link and the second link are an NSTR link pair, and the TWT SP partially overlaps with the MediumSyncDelay time,” the direct communication is “a time that does not overlap with the MediumSyncDelay time within the TWT SP + the AP MLD may be carried out in “additional time allotted by”.

The at least one processor further causes the STA MLD to transmit a third frame for early termination of the TWT SP when the direct communication is terminated, and to prematurely terminate the TWT SP after transmission of the third frame. can cause

According to the present disclosure, a communication node (e.g., station (STA), access point (AP), multi-link device (MLD)) operating on multiple links can set direct communication scheduling to perform direct communication. . Direct communication scheduling can be set up on multiple links where communication nodes operate or on a dedicated link used for direct communication. Direct communication section(s) can be set by direct communication scheduling. In the direct communication section(s), communication nodes can perform direct communication.

Before the direct communication section, the AP (e.g., AP MLD) may stop transmission to the STA (e.g., STA MLD) for which the direct communication section is set. An STA (eg, STA MLD) for which a direct communication section is set before the direct communication section may stop transmission. In the direct communication section, the AP may not transmit data (eg, a data frame) to the STA performing direct communication. The direct communication section may be terminated early. Direct communication scheduling may be terminated early. The direct communication section and/or direct communication scheduling may be adjusted. Therefore, direct communication can be performed smoothly in a wireless LAN that supports multiple links.

Figure 1 is a conceptual diagram showing a first embodiment of a wireless LAN system.
Figure 2 is a block diagram showing a first embodiment of a communication node constituting a wireless LAN system.
Figure 3 is a conceptual diagram showing a first embodiment of multiple links established between MLDs.
Figure 4 is a flowchart showing a first embodiment of a negotiation procedure for multi-link operation in a wireless LAN system.
Figure 5 is a timing diagram illustrating a first embodiment of a direct communication scheduling method in a wireless LAN.
Figure 6 is a timing diagram illustrating a second embodiment of a direct communication scheduling method in a wireless LAN.
Figure 7 is a timing diagram illustrating a third embodiment of a direct communication scheduling method in a wireless LAN.
FIG. 8A is a timing diagram illustrating a fourth embodiment of a direct communication scheduling method in a wireless LAN.
FIG. 8B is a timing diagram illustrating a fifth embodiment of a direct communication scheduling method in a wireless LAN.
FIG. 8C is a timing diagram illustrating a sixth embodiment of a direct communication scheduling method in a wireless LAN.
FIG. 9A is a timing diagram illustrating a seventh embodiment of a direct communication scheduling method in a wireless LAN.
FIG. 9B is a timing diagram illustrating an eighth embodiment of a direct communication scheduling method in a wireless LAN.
FIG. 10A is a timing diagram illustrating a ninth embodiment of a direct communication scheduling method in a wireless LAN.
FIG. 10B is a timing diagram illustrating a tenth embodiment of a direct communication scheduling method in a wireless LAN.
Figure 11 is a timing diagram showing an 11th embodiment of a direct communication scheduling method in wireless LAN.

Since the present disclosure can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present disclosure to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present disclosure.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be referred to as a second component, and similarly, the second component may be referred to as a first component without departing from the scope of the present disclosure. The term “and/or” includes any of a plurality of related stated items or a combination of a plurality of related stated items.

In embodiments of the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Additionally, in embodiments of the present disclosure, “one or more of A and B” may mean “one or more of A or B” or “one or more of combinations of one or more of A and B.”

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this disclosure are only used to describe specific embodiments and are not intended to limit the disclosure. Singular expressions include plural expressions unless the context clearly dictates otherwise. In the present disclosure, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which this disclosure pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted in an idealized or overly formal sense unless explicitly defined in the present disclosure. No.

Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. In order to facilitate overall understanding in explaining the present disclosure, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

Below, a wireless communication system to which embodiments according to the present disclosure are applied will be described. The wireless communication system to which the embodiments according to the present disclosure are applied is not limited to the content described below, and the embodiments according to the present disclosure can be applied to various wireless communication systems. A wireless communication system may be referred to as a “wireless communication network.”

Figure 1 is a conceptual diagram showing a first embodiment of a wireless LAN system.

Referring to FIG. 1, a wireless LAN system may include at least one basic service set (BSS). BSS refers to a set of stations (STA1, STA2 (AP1), STA3, STA4, STA5 (AP2), STA6, STA7, STA8) that are successfully synchronized and can communicate with each other, and is not a concept referring to a specific area. . In the embodiments below, a station that performs the function of an access point may be referred to as an “access point (AP),” and a station that does not perform the function of an access point may be referred to as a “non-AP station” or “station.” "It can be referred to as.

BSS can be divided into infrastructure BSS (infrastructure BSS) and independent BSS (IBSS). Here, BSS1 and BSS2 may mean infrastructure BSS, and BSS3 may mean IBSS. BSS1 is a distribution system that connects a first station (STA1), a first access point (STA2 (AP1)) providing distribution service, and a plurality of access points (STA2 (AP1), STA5 (AP2)) It may include a distribution system (DS). In BSS1, the first access point (STA2 (AP1)) can manage the first station (STA1).

BSS2 includes a third station (STA3), a fourth station (STA4), a second access point (STA5 (AP2)) providing distribution services, and a plurality of access points (STA2 (AP1), STA5 (AP2)). It may include a connecting distribution system (DS). In BSS2, the second access point (STA5 (AP2)) can manage the third station (STA3) and the fourth station (STA4).

BSS3 may refer to an IBSS operating in ad-hoc mode. In BSS3, there may not be an access point, which is a centralized management entity. In other words, in BSS3, the stations STA6, STA7, and STA8 can be managed in a distributed manner. In BSS3, all stations (STA6, STA7, STA8) may represent mobile stations, and are not allowed to access the distribution system (DS), so they form a self-contained network.

The access points (STA2 (AP1), STA5 (AP2)) may provide access to the distributed system (DS) via a wireless medium for the stations (STA1, STA3, STA4) associated with them. Communication between stations (STA1, STA3, STA4) in BSS1 or BSS2 is generally accomplished through access points (STA2 (AP1), STA5 (AP2)), but when a direct link is established, the stations ( Direct communication between STA1, STA3, and STA4) is possible.

Multiple infrastructure BSSs may be interconnected through a distribution system (DS). A plurality of BSSs connected through a distribution system (DS) are called an extended service set (ESS). Communication nodes (STA1, STA2 (AP1), STA3, STA4, STA5 (AP2)) included in the ESS can communicate with each other, and any station (STA1, STA3, STA4) within the same ESS can communicate without interruption. You can move from one BSS to another BSS.

A distribution system (DS) is a mechanism for one access point to communicate with another access point, whereby the access point transmits frames for stations associated with the BSS it manages or moves to another BSS. Frames can be transmitted for any station. Additionally, the access point can transmit and receive frames to and from external networks such as wired networks. This distribution system (DS) does not necessarily have to be a network, and there are no restrictions on its form as long as it can provide a certain distribution service specified in the IEEE 802.11 standard. For example, the distribution system may be a wireless network such as a mesh network, or it may be a physical structure that connects access points to each other. Communication nodes (STA1, STA2 (AP1), STA3, STA4, STA5 (AP2), STA6, STA7, STA8) included in the wireless LAN system may be configured as follows.

Figure 2 is a block diagram showing a first embodiment of a communication node constituting a wireless LAN system.

Referring to FIG. 2, the communication node 200 may include at least one processor 210, a memory 220, and a transmitting and receiving device 230 that is connected to a network and performs communication. The transmitting and receiving device 230 may be referred to as a transceiver, a radio frequency (RF) unit, an RF module, etc. Additionally, the communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, etc. Each component included in the communication node 200 is connected by a bus 270 and can communicate with each other.

However, each component included in the communication node 200 may be connected through an individual interface or individual bus centered on the processor 210, rather than the common bus 270. For example, the processor 210 may be connected to at least one of the memory 220, the transmission/reception device 230, the input interface device 240, the output interface device 250, and the storage device 260 through a dedicated interface. .

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260. The processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present disclosure are performed. Each of the memory 220 and the storage device 260 may be comprised of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may be comprised of at least one of read only memory (ROM) and random access memory (RAM).

FIG. 3 is a conceptual diagram illustrating a first embodiment of a multi-link established between multi-link devices (MLDs).

Referring to FIG. 3, the MLD may have one medium access control (MAC) address. In embodiments, MLD may refer to AP MLD and/or non-AP MLD. The MLD's MAC address can be used in the multi-link setup procedure between non-AP MLD and AP MLD. The MAC address of the AP MLD may be different from the MAC address of the non-AP MLD. Access point(s) associated with an AP MLD may have different MAC addresses, and station(s) associated with a non-AP MLD may have different MAC addresses. Access points within the AP MLD with different MAC addresses can be in charge of each link and can function as independent access points (APs).

Stations in a non-AP MLD with different MAC addresses can be in charge of each link and can perform the role of an independent station (STA). Non-AP MLD may also be referred to as STA MLD. MLD can support simultaneous transmit and receive (STR) operation. In this case, the MLD can perform a transmission operation on link 1 and a reception operation on link 2. An MLD that supports STR operation may be referred to as STR MLD (eg, STR AP MLD, STR non-AP MLD). In embodiments, a link may mean a channel or a band. A device that does not support STR operation may be referred to as a non-STR (NSTR) AP MLD or NSTR non-AP MLD (or NSTR STA MLD). AP in AP MLD may mean an AP linked to AP MLD. STA in STA MLD may mean an STA linked to STA MLD.

MLD can transmit and receive frames on multiple links by using a discontinuous bandwidth expansion method (e.g., 80MHz + 80MHz). Multi-link operation may include multi-band transmission. The AP MLD may include multiple access points, and the multiple access points may operate on different links. Each of the plurality of access points may perform the function(s) of the lower MAC layer. Each of the plurality of access points may be referred to as a “communication node” or “sub-entity.” A communication node (eg, an access point) may operate under the control of a higher layer (or the processor 210 shown in FIG. 2). A non-AP MLD may include multiple stations, and the multiple stations may operate on different links. Each of the plurality of stations may be referred to as a “communication node” or “sub-entity.” A communication node (eg, station) may operate under the control of a higher layer (or the processor 210 shown in FIG. 2).

MLD can perform communication in multi-band. For example, MLD can communicate using a 40MHz bandwidth in the 2.4GHz band depending on the channel expansion method (e.g., bandwidth expansion method), and communicate using a 160MHz bandwidth in the 5GHz band depending on the channel expansion method. can be performed. MLD can perform communication using a 160MHz bandwidth in the 5GHz band, and can perform communication using a 160MHz bandwidth in the 6GHz band. One frequency band (e.g., one channel) used by MLD can be defined as one link. Alternatively, multiple links may be established in one frequency band used by MLD. For example, MLD can establish one link in the 2.4GHz band and two links in the 6GHz band. Each link may be referred to as a first link, a second link, a third link, etc. Alternatively, each link may be referred to as link 1, link 2, link 3, etc. The link number may be set by the access point, and an ID (identifier) may be assigned to each link.

The MLD (e.g., AP MLD and/or non-AP MLD) may establish multiple links by performing an access procedure and/or negotiation procedure for multi-link operation. In this case, the number of links and/or the link to be used among multiple links may be set. A non-AP MLD (eg, station) can check band information capable of communicating with the AP MLD. In the negotiation procedure for multi-link operation between the non-AP MLD and the AP MLD, the non-AP MLD can configure one or more links among the links supported by the AP MLD to be used for the multi-link operation. A station that does not support multi-link operation (eg, IEEE 802.11a/b/g/n/ac/ax station) may be connected to one or more links among the multiple links supported by AP MLD.

If the band gap between multiple links (for example, the band gap between link 1 and link 2 in the frequency domain) is sufficient, the MLD can perform simultaneous transmission and reception (STR) operation. For example, the MLD may transmit PPDU (physical layer convergence procedure (PLCP) protocol data unit) 1 using link 1 among multiple links, and may receive PPDU 2 using link 2 among multiple links. On the other hand, if the MLD performs a STR operation when the band gap between multiple links is not sufficient, in-device coexistence (IDC) interference, which is interference between multiple links, may occur. Therefore, if the bandwidth gap between multiple links is not sufficient, MLD may not be able to perform STR operation.

For example, multiple links including Link 1, Link 2, and Link 3 may be established between AP MLD and non-AP MLD 1. If the band gap between Link 1 and Link 3 is sufficient, AP MLD can perform STR operation using Link 1 and Link 3. In other words, the AP MLD can transmit a frame using link 1 and receive a frame using link 3. If the band spacing between Link 1 and Link 2 is insufficient, AP MLD may not be able to perform STR operations using Link 1 and Link 2. If the band gap between Link 2 and Link 3 is not sufficient, AP MLD may not be able to perform STR operation using Link 2 and Link 3.

Figure 4 is a flowchart showing a first embodiment of a negotiation procedure for multi-link operation in a wireless LAN system.

Referring to FIG. 4, the connection procedure between a station (STA) and an access point (AP) in an infrastructure basic service set (BSS) includes a detection step of the access point (probe step) and an authentication step between the station and the detected access point. step), and an association step between the station and the authenticated access point.

In the detection phase, the station may detect one or more access points using a passive scanning method or an active scanning method. When a passive scanning method is used, a station can detect one or more access points by overhearing beacon frames transmitted by the one or more access points. When the active scanning method is used, the station may transmit a probe request frame and receive a probe response frame, which is a response to the probe request frame, from one or more access points, thereby accessing one or more access points. Points can be detected.

If one or more access points are detected, the station may perform authentication steps with the detected access point(s). In this case, the station can perform an authentication step with multiple access points. Authentication algorithms according to the IEEE 802.11 standard can be classified into an open system algorithm that exchanges two authentication frames, a shared key algorithm that exchanges four authentication frames, etc.

The station can transmit an authentication request frame based on the authentication algorithm according to the IEEE 802.11 standard, and can communicate with the access point by receiving an authentication response frame, which is a response to the authentication request frame, from the access point. Authentication can be completed.

When authentication with the access point is completed, the station can perform the connection step with the access point. In this case, the station can select one access point among itself and the access point(s) that performed the authentication step, and perform the connection step with the selected access point. That is, the station can transmit an association request frame to the selected access point, and establish a connection with the selected access point by receiving an association response frame, which is a response to the association request frame, from the selected access point. It can be completed.

Meanwhile, multi-link operation may be supported in a wireless LAN system. The MLD may include one or more STAs associated with the MLD. MLD may be a logical entity. MLD can be classified into AP MLD and non-AP MLD. Each STA associated with an AP MLD may be an AP, and each STA associated with a non-AP MLD may be a non-AP STA. To configure multiple links, a multi-link discovery procedure, a multi-link setup procedure, etc. may be performed. A multi-link discovery procedure may be performed in the detection phase between the station and the access point. In this case, a multi-link information element (ML IE) may be included in a beacon frame, probe request frame, and/or probe response frame.

For example, to perform multi-link operations, multi-link operations are used between an access point (e.g., an AP associated with an MLD) and a station (e.g., a non-AP STA associated with an MLD) in the detection phase. Information indicating availability and available link information may be exchanged. In a negotiation procedure for multi-link operation (eg, a multi-link setup procedure), the access point and/or station may transmit information about the link to be used for multi-link operation. The negotiation procedure for multi-link operation may be performed in the connection procedure (e.g., connection phase) between the station and the access point, and the information element(s) required for multi-link operation are included in the action frame in the negotiation procedure. It can be set or changed by.

Additionally, in a connection procedure (eg, connection step) between a station and an access point, available link(s) of the access point may be established, and an identifier (ID) may be assigned to each link. Thereafter, in the negotiation procedure and/or change procedure for multi-link operation, information indicating whether or not each link is activated may be transmitted, and the information may be expressed using a link ID.

Information indicating whether multi-link operation is available may be transmitted and received in the exchange procedure of a capability information element (e.g., an extremely high throughput (EHT) capability information element) between a station and an access point. there is. Capability information elements include information on the supporting band, information on the supporting links (e.g., ID and/or number of supporting links), and information on links capable of STR operation (e.g., band information on links). , interval information of links), etc. Additionally, the capability information element may include information individually indicating links capable of STR operation.

In the present disclosure, the operation of the STA MLD may be interpreted as the operation of the STA associated with the STA MLD, and the operation of the STA may be interpreted as the operation of the STA MLD associated with the STA. The operation of the AP MLD can be interpreted as the operation of the AP associated with the AP MLD, and the operation of the AP can be interpreted as the operation of the AP MLD associated with the AP.

Figure 5 is a timing diagram illustrating a first embodiment of a direct communication scheduling method in a wireless LAN.

Referring to FIG. 5, AP MLD and non-AP MLD (eg, STA MLD) can operate in multiple links. The STA MLD may perform direct communication (eg, TDLS (tunneled direct link setup) operation, TDLS communication) on the second link. The second link may be one link among multiple links in which AP MLD and STA MLD operate. The second link may be a dedicated link for direct communication (eg, off channel, off link). A TDLS receiving STA (eg, TDLS recipient) that is the target of direct communication may operate on the second link. AP MLD may not operate in off-channel. The first link and the second link may be a non-STR (NSTR) link pair for the STA MLD. The STA MLD may be an enhanced multi-link single radio (EMLSR) STA MLD. The first link and the second link may be EMLSR links. Embodiments according to the present disclosure may be applied to EMLSR STA MLD (eg, EMLSR operation). For example, “if the STA MLD is an EMLSR STA MLD and the first link and the second link are EMLSR links,” the operation on the first link and the second link may be the same or similar to the operation on the NSTR link pair.

The STA MLD may transmit a channel usage request frame to the AP MLD to perform direct communication. The channel use request frame may be referred to as a first frame. The AP MLD can receive a channel use request frame from the STA MLD and check the information element(s) included in the channel use request frame. The AP MLD may transmit a response frame to the channel use request frame to the STA MLD. In the present disclosure, the response frame may mean an acknowledgment (ACK) frame or a block ACK (BA) frame. A channel use request frame may be transmitted and received on the first link. The channel use request frame may include information on the channel and/or link that the STA MLD wishes to use (for example, information on the second link). In other words, the channel use request frame may include information on a channel and/or link through which the STA MLD directly communicates. Direct communication may be communication between STAs. The channel use request frame may include one or more target wake time (TWT) information elements (eg, TWT information, TWT element). The TWT information element may include a flow identifier (e.g., flow ID) that identifies the TWT request. The TWT information element(s) included in the channel use request frame may indicate the TWT SP (e.g., off channel TWT SP) with which the STA MLD wishes to perform direct communication. The TWT SP where direct communication is performed may mean a direct communication section.

The AP MLD may transmit a channel usage response frame to the STA MLD in response to the channel use request frame. In other words, the AP MLD may determine the link and/or channel on which the STA MLD performs direct communication based on the information element(s) included in the channel use request frame, and the STA MLD's direct communication on the link and/or channel The TWT SP where communication is performed can be determined. The AP MLD may transmit to the STA MLD a channel usage response frame containing “information of the links and/or channels on which direct communication of the STA MLD is permitted” and/or “information of the TWT SP on which direct communication of the STA MLD is permitted.” there is. The STA MLD can receive a channel use response frame from the AP MLD and check the information element(s) included in the channel use response frame. The STA MLD may transmit a response frame (e.g., ACK frame) for the channel use response frame to the AP MLD. The channel use response frame may be referred to as a second frame.

The channel use response frame may include information about the channel and/or link requested by the STA MLD. In other words, the channel use response frame may include information on the channel and/or link through which the STA MLD directly communicates. The channel usage response frame may include one or more TWT information elements. In other words, the TWT information element(s) included in the channel use response frame may indicate the TWT SP (e.g., off-channel TWT SP, direct communication section) with which the STA MLD performs direct communication. The channel use response frame may include a timeout interval element.

By exchanging channel use request/response frames containing TWT information element(s) between the STA MLD and AP MLD, TWT settings (e.g., TWT agreement) for TDLS between STA MLD and AP MLD can be negotiated. You can. The channel use request/response frame may mean a channel use request frame and/or a channel use response frame. TWT setup for TDLS may be referred to as off-channel TWT or off-channel TWT agreement. A TWT service period (SP) scheduled based on the off-channel TWT agreement may be referred to as an off-channel TWT SP or an off-channel TWT schedule. The off-channel TWT agreement can be used until the time indicated by the timeout interval element included in the channel use response frame transmitted by the AP MLD.

An off-channel TWT SP may be scheduled on the second link. STA MLD can set TXOP so that TXOP (transmit opportunity) ends before the off-channel TWT SP of the second link. Within TXOP, communication between STA MLD and AP MLD can be performed. Alternatively, the STA MLD may terminate TXOP early before the off-channel TWT SP of the second link. The AP MLD may set the TXOP so that the TXOP in which transmission to the STA MLD is performed ends before the off-channel TWT SP of the second link. Alternatively, the AP MLD may terminate TXOP early before the off-channel TWT SP of the second link.

Since the first link and the second link on which the STA MLD operates are an NSTR link pair, the STA MLD performs a standby operation (e.g., a standby operation (e.g., For example, a CCA (clear channel assessment) operation can be performed. MediumSyncDelay time may mean medium synchronization delay time. MediumSyncDelay time may mean time according to the MediumSyncDelay timer. In order to ensure that the STA MLD's direct communication is not affected by the MediumSyncDelay time, the STA MLD can set the TXOP so that the TXOP ends before the MediumSyncDelay time from the start of the off-channel TWT SP of the second link. Alternatively, the STA MLD may terminate the TXOP early before the MediumSyncDelay time from the start of the off-channel TWT SP of the second link. The AP MLD may set the TXOP so that the TXOP in which transmission to the STA MLD is performed ends before the MediumSyncDelay time from the start of the off-channel TWT SP of the second link. Alternatively, the AP MLD may terminate the TXOP early so that the TXOP in which transmission to the STA MLD is performed ends before the MediumSyncDelay time from the start of the off-channel TWT SP of the second link.

The STA MLD may be an EMLSR MLD (eg, EMLSR STA MLD). If the STA MLD is EMLSR MLD, EMLSR transition delay, which is the transition time of transmission and reception operations between links, may be additionally required. To ensure that the STA MLD's direct communication is not affected by the MediumSyncDelay time and EMLSR transition delay, the STA MLD sets the TXOP so that the TXOP ends before "MediumSyncDelay time + EMLSR transition delay" from the start of the off-channel TWT SP of the second link. You can. Alternatively, the STA MLD may terminate the TXOP early before “MediumSyncDelay time + EMLSR transition delay” from the start of the off-channel TWT SP of the second link. The AP MLD may set the TXOP so that the TXOP in which transmission to the STA MLD is performed ends before “MediumSyncDelay time + EMLSR transition delay” from the start of the off-channel TWT SP of the second link. Alternatively, the AP MLD may terminate the TXOP early so that the TXOP in which transmission to the STA MLD is performed is terminated before “MediumSyncDelay time + EMLSR transition delay” from the start of the off-channel TWT SP of the second link.

The STA MLD may perform direct communication (e.g., peer-to-peer communication, TDLS communication) with a TDLS recipient (e.g., another STA, another STA MLD) in the off-channel TWT SP. The AP MLD may not transmit frames to the STA MLD on the first link that is the second link and the NSTR link pair for a time corresponding to the off-channel TWT SP of the second link. In other words, the STA MLD may not expect to receive a frame from the AP MLD on the first link that is the second link and the NSTR link pair during a time corresponding to the off-channel TWT SP of the second link.

The STA MLD may perform CCA within the MediumSyncDelay time of the second link, and the energy level detected by CCA may be below a certain value. If the energy level is below a certain value, the STA MLD may transmit an RTS frame to the TDLS receiver on the second link. If the STA MLD transmits an RTS frame, the MediumSyncDelay time may end early, and the STA MLD may perform communication within the off-channel TWT SP.

Figure 6 is a timing diagram illustrating a second embodiment of a direct communication scheduling method in a wireless LAN.

Referring to FIG. 6, AP MLD and non-AP MLD (eg, STA MLD) can operate in multiple links. The STA MLD may perform direct communication (e.g., TDLS operation, TDLS communication) on the second link. The second link may be one link among multiple links in which AP MLD and STA MLD operate. The second link may be a dedicated link for direct communication (eg, off-channel, off-link). A TDLS receiving STA (eg, TDLS receiver) that is the target of direct communication may operate on the second link. AP MLD may not operate in off-channel. The first link and the second link may be an NSTR link pair of the STA MLD. STA MLD may be EMLSR STA MLD. The first link and the second link may be EMLSR links. Embodiments according to the present disclosure may be applied to EMLSR STA MLD (eg, EMLSR operation). For example, “if the STA MLD is an EMLSR STA MLD and the first link and the second link are EMLSR links,” the operation on the first link and the second link may be the same or similar to the operation on the NSTR link pair.

The STA MLD may transmit a channel use request frame to the AP MLD to perform direct communication. The AP MLD can receive a channel use request frame from the STA MLD and check the information element(s) included in the channel use request frame. The AP MLD may transmit a response frame to the channel use request frame to the STA MLD. A channel use request frame may be transmitted and received on the first link. The channel use request frame may include information on the channel and/or link that the STA MLD wishes to use (for example, information on the second link). In other words, the channel use request frame may include information on a channel and/or link through which the STA MLD directly communicates. The channel use request frame may include one or more TWT information elements (eg, TWT information, TWT element). The TWT information element may include a flow identifier (e.g., flow ID) that identifies the TWT request. The TWT information element(s) included in the channel use request frame may indicate the TWT SP (e.g., off-channel TWT SP, direct communication section) with which the STA MLD wishes to perform direct communication.

The AP MLD may transmit a channel use response frame to the STA MLD in response to the channel use request frame. In other words, the AP MLD may determine the link and/or channel on which the STA MLD performs direct communication based on the information element(s) included in the channel use request frame, and the STA MLD's direct communication on the link and/or channel The TWT SP where communication is performed can be determined. The AP MLD may transmit to the STA MLD a channel usage response frame containing “information of the links and/or channels on which direct communication of the STA MLD is permitted” and/or “information of the TWT SP on which direct communication of the STA MLD is permitted.” there is. The STA MLD can receive a channel use response frame from the AP MLD and check the information element(s) included in the channel use response frame. The STA MLD may transmit a response frame for the channel use response frame to the AP MLD. The channel use response frame may include information about the channel and/or link requested by the STA MLD. The channel usage response frame may include one or more TWT information elements. The channel usage response frame may include a timeout interval element.

By exchanging channel use request/response frames containing TWT information element(s) between the STA MLD and the AP MLD, TWT settings (e.g., TWT agreement) for TDLS between the STA MLD and the AP MLD can be negotiated. TWT setup for TDLS may be referred to as off-channel TWT or off-channel TWT agreement. A TWT SP scheduled based on an off-channel TWT agreement may be referred to as an off-channel TWT SP or an off-channel TWT schedule. The off-channel TWT agreement can be used until the time indicated by the timeout interval element included in the channel use response frame transmitted by the AP MLD.

An off-channel TWT SP may be scheduled on the second link. STA MLD can set TXOP so that TXOP ends before the off-channel TWT SP of the second link. In TXOP, communication between STA MLD and AP MLD can be performed. Alternatively, the STA MLD may terminate TXOP early before the off-channel TWT SP of the second link. The AP MLD may set the TXOP so that the TXOP in which transmission to the STA MLD is performed ends before the off-channel TWT SP of the second link. Alternatively, the AP MLD may terminate TXOP early before the off-channel TWT SP of the second link.

Since the first link and the second link on which the STA MLD operates are an NSTR link pair, the STA MLD performs a standby operation (e.g., a standby operation (e.g., For example, CCA operation) can be performed. To ensure that the STA MLD's direct communication is not affected by the MediumSyncDelay time, the off-channel TWT SP can be set to include the MediumSyncDelay time. After the end of the MediumSyncDelay time, the STA MLD can perform direct communication (e.g., peer-to-peer communication, TDLS communication) with the TDLS receiver within the remaining time of the off-channel TWT SP. For example, the remaining time of the off-channel TWT SP may be “Length of the off-channel TWT SP - MediumSyncDelay time”. The MediumSyncDelay time may be the time from the start of the MediumSyncDelay timer to the end of the MediumSyncDelay timer.

The STA MLD may be an EMLSR MLD (eg, EMLSR STA MLD). If the STA MLD is EMLSR MLD, EMLSR transition delay, which is the transition time of transmission and reception operations between links, may be additionally required. To ensure that the STA MLD's direct communication is not affected by the MediumSyncDelay time and EMLSR transition delay, the off-channel TWT SP can be set to include the MediumSyncDelay time and EMLSR transition delay time. After the end of "EMLSR transition delay + MediumSyncDelay time", within the remaining time of the off-channel TWT SP, the STA MLD can perform direct communication (e.g. peer-to-peer communication, TDLS communication) with the TDLS receiver. . For example, the remaining time of the off-channel TWT SP may be “length of the off-channel TWT SP - EMLSR transition delay time - MediumSyncDelay time.” The AP MLD may not transmit frames to the STA MLD on the first link that is the second link and the NSTR link pair for a time corresponding to the off-channel TWT SP of the second link. In other words, the STA MLD may not expect to receive a frame from the AP MLD on the first link that is the second link and the NSTR link pair during a time corresponding to the off-channel TWT SP of the second link.

During the MediumSyncDelay time in the off-channel TWT SP, the STA MLD may perform CCA on the second link, and the energy level detected by the CCA may be below a certain value. If the energy level is below a certain value, the STA MLD may transmit an RTS frame to the TDLS receiver in the second link. If the STA MLD transmits an RTS frame, the MediumSyncDelay time may end early, and the STA MLD may perform communication within the off-channel TWT SP.

Figure 7 is a timing diagram illustrating a third embodiment of a direct communication scheduling method in a wireless LAN.

Referring to FIG. 7, AP MLD and non-AP MLD (eg, STA MLD) can operate in multiple links. The STA MLD may perform direct communication (e.g., TDLS operation, TDLS communication) on the second link. The second link may be one link among multiple links in which AP MLD and STA MLD operate. The second link may be a dedicated link for direct communication (eg, off-channel, off-link). A TDLS receiving STA (eg, TDLS receiver) that is the target of direct communication may operate on the second link. AP MLD may not operate in off-channel. The first link and the second link may be an NSTR link pair of the STA MLD. STA MLD may be EMLSR STA MLD. The first link and the second link may be EMLSR links. Embodiments according to the present disclosure may be applied to EMLSR STA MLD (eg, EMLSR operation). For example, “if the STA MLD is an EMLSR STA MLD and the first link and the second link are EMLSR links,” the operation on the first link and the second link may be the same or similar to the operation on the NSTR link pair.

The STA MLD may transmit a channel use request frame to the AP MLD to perform direct communication. The AP MLD can receive a channel use request frame from the STA MLD and check the information element(s) included in the channel use request frame. The AP MLD may transmit a response frame to the channel use request frame to the STA MLD. A channel use request frame may be transmitted and received on the first link. The channel use request frame may include information on the channel and/or link that the STA MLD wishes to use (for example, information on the second link). In other words, the channel use request frame may include information on a channel and/or link through which the STA MLD directly communicates. The channel use request frame may include one or more TWT information elements (eg, TWT information, TWT element). The TWT information element may include a flow identifier (e.g., flow ID) that identifies the TWT request. The TWT information element(s) included in the channel use request frame may indicate the TWT SP (e.g., off-channel TWT SP) with which the STA MLD wishes to perform direct communication.

The AP MLD may transmit a channel use response frame to the STA MLD in response to the channel use request frame. In other words, the AP MLD may determine the link and/or channel on which the STA MLD performs direct communication based on the information element(s) included in the channel use request frame, and the STA MLD's direct communication on the link and/or channel The TWT SP where communication is performed can be determined. The AP MLD may transmit to the STA MLD a channel usage response frame containing “information of the links and/or channels on which direct communication of the STA MLD is permitted” and/or “information of the TWT SP on which direct communication of the STA MLD is permitted.” there is. The STA MLD can receive a channel use response frame from the AP MLD and check the information element(s) included in the channel use response frame. The STA MLD may transmit a response frame for the channel use response frame to the AP MLD. The channel use response frame may include information on the channel and/or link requested by the STA MLD. The channel usage response frame may include one or more TWT information elements. In other words, the TWT information element(s) included in the channel use response frame may indicate the TWT SP (e.g., off-channel TWT SP, direct communication section) with which the STA MLD performs direct communication. The channel usage response frame may include a timeout interval element.

By exchanging channel use request/response frames containing TWT information element(s) between the STA MLD and the AP MLD, TWT settings (e.g., TWT agreement) for TDLS between the STA MLD and the AP MLD can be negotiated. TWT setup for TDLS may be referred to as off-channel TWT or off-channel TWT agreement. A TWT SP scheduled based on an off-channel TWT agreement may be referred to as an off-channel TWT SP or an off-channel TWT schedule. The off-channel TWT agreement can be used until the time indicated by the timeout interval element included in the channel use response frame transmitted by the AP MLD.

An off-channel TWT SP may be scheduled on the second link. STA MLD can set TXOP so that TXOP ends before the off-channel TWT SP of the second link. Alternatively, the STA MLD may terminate TXOP early before the off-channel TWT SP of the second link. The AP MLD may set the TXOP so that the TXOP in which transmission to the STA MLD is performed ends before the off-channel TWT SP of the second link. Alternatively, the AP MLD may terminate TXOP early before the off-channel TWT SP of the second link.

Since the first link and the second link on which the STA MLD operates are an NSTR link pair, the STA MLD performs a standby operation (e.g., a standby operation (e.g., For example, CCA operation) can be performed. The off-channel TWT may overlap some or all of the MediumSyncDelay time. In this case, the STA MLD may not be able to perform direct communication. In the above situation, in order to ensure that the STA MLD's direct communication is not affected by the MediumSyncDelay time, the AP MLD may consider the STA MLD's MediumSyncDelay time.

For example, when the AP MLD receives a frame from the STA MLD on the first link, the AP MLD may determine (e.g., predict) that the MediumSyncDelay timer is applied on the second link of the STA MLD, and the MediumSyncDelay timer You can predict the end point (e.g., MediumSyncDelay time). “If the STA MLD’s MediumSyncDelay timer is applied, the end time of the MediumSyncDelay timer is predicted, and the MediumSyncDelay time overlaps with the off-channel TWT SP,” the AP MLD can calculate additional consideration time. The AP MLD can allocate additional consideration time to the STA MLD, and the STA MLD can check the additional consideration time allocated by the AP MLD. Additional consideration time may be referred to as additional time. Additional consideration time may be applied differently depending on the condition(s) below.

Condition 1: If the off-channel TWT SP completely overlaps the MediumSyncDelay time, the additional consideration time is “a time corresponding to the length of the off-channel TWT SP”, “a time shorter than the length of the off-channel TWT SP”, or “the time corresponding to the length of the off-channel TWT SP”. It can be “more than a length of time.”

Condition 2: If the off-channel TWT SP partially overlaps the MediumSyncDelay time, the additional consideration time is "the time corresponding to the length of the off-channel TWT SP overlapping with the MediumSyncDelay time", "the length of the off-channel TWT SP overlapping with the MediumSyncDelay time" It may be “a shorter time” or “a time greater than or equal to the length of the off-channel TWT SP overlapped with the MediumSyncDelay time.”

AP MLD's additional consideration time can be applied after the end of STA MLD's MediumSyncDelay timer. STA MLD communicates directly with TDLS recipients (e.g. peer-to-peer communication) within “off-channel TWT SP (e.g., off-channel TWT SP that does not overlap MediumSyncDelay time) + additional consideration time of AP MLD” , TDLS communication) can be performed. The AP MLD is the first link pair of the second link and the NSTR link for a time corresponding to “the off-channel TWT SP of the second link (e.g., the off-channel TWT SP that does not overlap with the MediumSyncDelay time) + the additional consideration time of the AP MLD.” The link may not transmit frames to the STA MLD. In other words, the STA MLD is the second link and the NSTR link during a time corresponding to “the off-channel TWT SP of the second link (e.g., the off-channel TWT SP that does not overlap with the MediumSyncDelay time) + the additional consideration time of the AP MLD” It may not expect to receive frames from the AP MLD on the first link of the pair.

The STA MLD may perform CCA within the MediumSyncDelay time of the second link, and the energy level detected by CCA may be below a certain value. If the energy level is below a certain value, the STA MLD may transmit an RTS frame to the TDLS receiver on the second link. If the STA MLD transmits an RTS frame, the MediumSyncDelay time may end early, and the STA MLD may perform communication within the off-channel TWT SP.

FIG. 8A is a timing diagram showing a fourth embodiment of a direct communication scheduling method in a wireless LAN, FIG. 8B is a timing diagram showing a fifth embodiment of a direct communication scheduling method in a wireless LAN, and FIG. 8C is a wireless LAN. This is a timing diagram showing the sixth embodiment of the direct communication scheduling method in the LAN.

Referring to FIGS. 8A, 8B, and 8C, AP MLD and non-AP MLD (eg, STA MLD) may operate in multiple links. The STA MLD may perform direct communication (e.g., TDLS operation, TDLS communication) on a second link or a dedicated link for direct communication (e.g., off-channel, off-link). Off-channel and off-link may have the same meaning. The second link may be one link among multiple links in which AP MLD and STA MLD operate. An off-channel may be a dedicated channel (e.g., a dedicated link) for direct communication. A TDLS receiving STA (eg, TDLS receiver) that is the target of direct communication may operate in the second link or off channel. AP MLD may not operate in off-channel.

In the embodiment of FIG. 8A, the first link and the second link may be an NSTR link pair of the STA MLD. In the embodiment of FIG. 8B, the first link and the off channel may be an NSTR link pair of the STA MLD. In the embodiment of Figure 8C, the first link and the second link may be STR links (e.g., link(s) that are not an NSTR link pair) in the STA MLD, and the second link and off channel may be NSTR links in the STA MLD. It can be a pair. In a STR link, the STA MLD can perform STR operations. STA MLD may be EMLSR STA MLD. 8A and 8B, the first link and the second link may be EMLSR links. In the embodiment of FIG. 8C, the first link and the second link may be STR links of the STA MLD, and the second link and the off channel may be EMLSR links. Embodiments according to the present disclosure may be applied to EMLSR STA MLD (eg, EMLSR operation). For example, “if the STA MLD is an EMLSR STA MLD and the first link and the second link are EMLSR links,” the operation on the first link and the second link may be the same or similar to the operation on the NSTR link pair.

The STA MLD may transmit a channel use request frame to the AP MLD to perform direct communication. The AP MLD can receive a channel use request frame from the STA MLD and check the information element(s) included in the channel use request frame. The AP MLD may transmit a response frame to the channel use request frame to the STA MLD. A channel use request frame may be transmitted and received on the first link. The channel use request frame may include information on the channel and/or link that the STA MLD wishes to use (e.g., information on the second link, information on the off channel). In other words, the channel use request frame may include information on a channel and/or link through which the STA MLD directly communicates. The channel use request frame may include one or more target wake time (TWT) information elements (eg, TWT information, TWT element). The TWT information element may include a flow identifier (e.g., flow ID) that identifies the TWT request. The TWT information element(s) included in the channel use request frame may indicate the TWT SP (e.g., off-channel TWT SP) with which the STA MLD wishes to perform direct communication.

The AP MLD may transmit a channel use response frame to the STA MLD in response to the channel use request frame. In other words, the AP MLD may determine the link and/or channel on which the STA MLD performs direct communication based on the information element(s) included in the channel use request frame, and the STA MLD's direct communication on the link and/or channel The TWT SP where communication is performed can be determined. The AP MLD may transmit to the STA MLD a channel usage response frame containing “information of the links and/or channels on which direct communication of the STA MLD is permitted” and/or “information of the TWT SP on which direct communication of the STA MLD is permitted.” there is. The STA MLD can receive a channel use response frame from the AP MLD and check the information element(s) included in the channel use response frame. The STA MLD may transmit a response frame for the channel use response frame to the AP MLD. The channel use response frame may include information about the channel and/or link requested by the STA MLD. In other words, the channel use response frame may include information on the channel and/or link through which the STA MLD directly communicates. The channel usage response frame may include one or more TWT information elements. In other words, the TWT information element(s) included in the channel use response frame may indicate the TWT SP (e.g., off-channel TWT SP, direct communication section) with which the STA MLD performs direct communication. The channel usage response frame may include a timeout interval element.

By exchanging channel use request/response frames containing TWT information element(s) between the STA MLD and the AP MLD, TWT settings (e.g., TWT agreement) for TDLS between the STA MLD and the AP MLD can be negotiated. TWT setup for TDLS may be referred to as off-channel TWT or off-channel TWT agreement. A TWT SP scheduled based on an off-channel TWT agreement may be referred to as an off-channel TWT SP or an off-channel TWT schedule. The off-channel TWT agreement can be used until the time indicated by the timeout interval element included in the channel use response frame transmitted by the AP MLD. The AP MLD may not transmit frames to the STA MLD on link(s) that are a pair of a link to which the off-channel TWT SP is applied and an NSTR link during the time corresponding to the off-channel TWT SP.

Referring to FIG. 8A, the off-channel TWT SP may be scheduled on the second link. The STA MLD may perform direct communication (e.g., peer-to-peer communication, TDLS communication) with the TDLS receiver in the off-channel TWT SP of the second link. Direct communication can be terminated prematurely. To terminate direct communication early in the off-channel TWT SP (or to terminate the off-channel TWT SP early when direct communication is terminated), the STA MLD is set to a first value (e.g., 1). A frame (hereinafter referred to as an “EOSP frame”) having a medium access control (MAC) header including an end of service period (EOSP) field may be transmitted to the AP MLD. Alternatively, to terminate direct communication early in the off-channel TWT SP (or to terminate the off-channel TWT SP early when direct communication is terminated), the STA MLD may transmit a random frame to the AP MLD. You can. The AP MLD may receive an EOSP frame or arbitrary frame from the STA MLD, and may transmit a response frame (e.g., an ACK frame or BA frame) for the EOSP frame or arbitrary frame to the STA MLD, and an off-channel TWT SP can be terminated early. Additionally, the STA MLD may terminate the off-channel TWT SP early after transmitting an EOSP frame or an arbitrary frame.

Referring to Figure 8b, the off-channel TWT SP can be scheduled in the off-channel. The STA MLD can perform direct communication (e.g., peer-to-peer communication, TDLS communication) with the TDLS receiver in the off-channel TWT SP of the off-channel. Direct communication may be terminated prematurely. To terminate direct communication early in the off-channel TWT SP (or to terminate the off-channel TWT SP early when direct communication is terminated), the STA MLD is set to a first value (e.g., 1). A quality of service (QoS) Null frame with a MAC header including an EOSP field can be transmitted to the AP MLD. The A-Control field of the MAC header included in the QoS Null frame may include information indicating a TWT flow identifier and/or off channel. The AP MLD may receive a QoS Null frame from the STA MLD, may transmit a response frame (e.g., ACK frame or BA frame) for the QoS Null frame to the STA MLD, and may terminate the off-channel TWT SP early. there is. STA MLD may terminate the off-channel TWT SP early after transmitting a QoS Null frame.

Alternatively, the STA MLD may transmit a clear to send (CTS)-to-self frame on the first link including a receiver address (RA) field set to the address of the STA MLD of the first link. The duration of the CTS-to-Self frame can be set to 0. If a CTS-to-Self frame is received from the STA MLD, the AP MLD may terminate the off-channel TWT SP early. The STA MLD may terminate the off-channel TWT SP early after transmitting the CTS-to-Self frame.

Alternatively, the STA MLD may transmit a request to send (RTS) frame to the AP MLD (eg, AP) on the first link. The duration of the RTS frame can be set to 0. If an RTS frame with a duration set to 0 is received from the STA MLD, the AP MLD may terminate the off-channel TWT SP early. The STA MLD may terminate the off-channel TWT SP early after transmitting the RTS frame. Alternatively, the duration of the RTS frame may be set to a time corresponding to “SIFS (short interframe space) + the length of the CTS frame that is the response to the RTS frame.” When an RTS frame with a duration set to the time corresponding to the "length of SIFS + CTS frame" is received from the STA MLD, the AP MLD may transmit the CTS frame to the STA MLD, and the AP MLD may terminate the off-channel TWT SP early can do. The STA MLD may terminate the off-channel TWT SP early after receiving the CTS frame for the RTS frame.

Alternatively, the STA MLD may transmit arbitrary frames to the AP MLD on the first link. The AP MLD can receive arbitrary frames from the STA MLD and can terminate the off-channel TWT SP early. The STA MLD may terminate the off-channel TWT SP early after transmitting any frame.

Referring to Figure 8c, the off-channel TWT SP can be scheduled in the off-channel. The STA MLD can perform direct communication (e.g., peer-to-peer communication, TDLS communication) with the TDLS receiver in the off-channel TWT SP of the off-channel. Direct communication can be terminated prematurely. After direct communication is terminated, the MediumSyncDelay timer may run on the second link, which is an off-channel and NSTR link pair. In this case, the STA MLD may not transmit a frame for early termination of direct communication in the off-channel TWT SP to the AP MLD on the second link. In the above situation, to terminate direct communication early in the off-channel TWT SP (or to terminate the off-channel TWT SP early when direct communication is terminated), the STA MLD is set to a first value (e.g., A QoS Null frame with a MAC header including an EOSP field set to 1) can be transmitted to the AP MLD on the first link other than the off-channel and NSTR link pair.

The MAC header included in the QoS Null frame may include information indicating a TWT flow identifier and/or off channel. For example, the MAC header of the QoS Null frame may include an A-control field, and the A-control field may include information indicating a TWT flow identifier and/or off channel. The AP MLD may receive a QoS Null frame from the STA MLD, may transmit a response frame (e.g., ACK frame or BA frame) for the QoS Null frame to the STA MLD, and may terminate the off-channel TWT SP early. there is. STA MLD may terminate the off-channel TWT SP early after transmitting a QoS Null frame. STA MLD may generate the information indicating the TWT flow identifier and/or off channel as a separate frame (e.g., TWT information frame, frame containing TWT element), and the separate frame and QoS Null frame An A(aggregate)-MPDU consisting of may be transmitted.

Alternatively, the STA MLD may transmit on the first link a CTS frame (e.g., CTS-to-Self frame) including an RA field set to the address of the STA MLD of the first link. The duration of the CTS-to-Self frame can be set to 0. If a CTS-to-Self frame is received from the STA MLD, the AP MLD may terminate the off-channel TWT SP early. The STA MLD may terminate the off-channel TWT SP early after transmitting the CTS-to-Self frame.

Alternatively, the STA MLD may transmit an RTS frame to the AP MLD (eg, AP) on the first link. The duration of the RTS frame can be set to 0. If an RTS frame with a duration set to 0 is received from the STA MLD, the AP MLD may terminate the off-channel TWT SP early. The STA MLD may terminate the off-channel TWT SP early after transmitting the RTS frame. Alternatively, the duration of the RTS frame may be set to a time corresponding to “SIFS + length of the CTS frame that is the response to the RTS frame.” When an RTS frame with a duration set to the time corresponding to the "length of SIFS + CTS frame" is received from the STA MLD, the AP MLD may transmit the CTS frame to the STA MLD, and the AP MLD may terminate the off-channel TWT SP early can do. The STA MLD may terminate the off-channel TWT SP early after receiving the CTS frame for the RTS frame.

Alternatively, the STA MLD may transmit arbitrary frames to the AP MLD on the first link. The AP MLD can receive arbitrary frames from the STA MLD and can terminate the off-channel TWT SP early. The STA MLD may terminate the off-channel TWT SP early after transmitting any frame.

In the embodiments of FIGS. 8A to 8C, the STA MLD may perform CCA within the MediumSyncDelay time of the second link, and the energy level detected by the CCA may be below a certain value. If the energy level is below a certain value, the STA MLD may transmit an RTS frame to the TDLS receiver on the second link. If the STA MLD transmits an RTS frame, the MediumSyncDelay time may end early, and the STA MLD may perform communication within the off-channel TWT SP.

FIG. 9A is a timing diagram showing a seventh embodiment of a direct communication scheduling method in a wireless LAN, and FIG. 9B is a timing diagram showing an eighth embodiment of a direct communication scheduling method in a wireless LAN.

Referring to FIGS. 9A and 9B, AP MLD and non-AP MLD (eg, STA MLD) may operate in multiple links. The STA MLD may perform direct communication (e.g., TDLS operation, TDLS communication) on a second link or a dedicated link for direct communication (e.g., off-channel, off-link). Off-channel and off-link may have the same meaning. The second link may be one link among multiple links in which AP MLD and STA MLD operate. An off-channel may be a dedicated channel (e.g., a dedicated link) for direct communication. A TDLS receiving STA (eg, TDLS receiver) that is the target of direct communication may operate in the second link or off channel. AP MLD may not operate in off-channel.

In the embodiment of FIG. 9A, the first link and the second link may be an NSTR link pair of the STA MLD. In the embodiment of FIG. 9B, the first link and the off channel may be an NSTR link pair of the STA MLD. STA MLD may be EMLSR STA MLD. The first link and the second link may be EMLSR links. Embodiments according to the present disclosure may be applied to EMLSR STA MLD (eg, EMLSR operation). For example, “if the STA MLD is an EMLSR STA MLD and the first link and the second link are EMLSR links,” the operation on the first link and the second link may be the same or similar to the operation on the NSTR link pair.

The STA MLD may transmit a channel use request frame to the AP MLD to perform direct communication. The AP MLD can receive a channel use request frame from the STA MLD and check the information element(s) included in the channel use request frame. The AP MLD may transmit a response frame to the channel use request frame to the STA MLD. A channel use request frame may be transmitted and received on the first link. The channel use request frame may include information on the channel and/or link that the STA MLD wishes to use (e.g., information on the second link, information on the off channel). In other words, the channel use request frame may include information on a channel and/or link through which the STA MLD directly communicates. The channel use request frame may include one or more target wake time (TWT) information elements (eg, TWT information, TWT element). The TWT information element may include a flow identifier (e.g., flow ID) that identifies the TWT request. A plurality of TWT information elements may include different TWT flow IDs. The TWT information element(s) included in the channel use request frame may indicate the TWT SP (e.g., off-channel TWT SP) with which the STA MLD wishes to perform direct communication.

The AP MLD may transmit a channel use response frame to the STA MLD in response to the channel use request frame. In other words, the AP MLD may determine the link and/or channel on which the STA MLD performs direct communication based on the information element(s) included in the channel use request frame, and the STA MLD's direct communication on the link and/or channel The TWT SP where communication is performed can be determined. The AP MLD may transmit to the STA MLD a channel usage response frame containing “information of the links and/or channels on which direct communication of the STA MLD is permitted” and/or “information of the TWT SP on which direct communication of the STA MLD is permitted.” there is. The STA MLD can receive a channel use response frame from the AP MLD and check the information element(s) included in the channel use response frame. The STA MLD may transmit a response frame for the channel use response frame to the AP MLD. The channel use response frame may include information about the channel and/or link requested by the STA MLD. In other words, the channel use response frame may include information on the channel and/or link through which the STA MLD directly communicates. The channel usage response frame may include one or more TWT information elements. In other words, the TWT information element(s) included in the channel use response frame may indicate the TWT SP (e.g., off-channel TWT SP, direct communication section) with which the STA MLD performs direct communication. The channel usage response frame may include a timeout interval element.

By exchanging channel use request/response frames containing TWT information element(s) between the STA MLD and the AP MLD, TWT settings (e.g., TWT agreement) for TDLS between the STA MLD and the AP MLD can be negotiated. TWT setup for TDLS may be referred to as off-channel TWT or off-channel TWT agreement. A TWT SP scheduled based on an off-channel TWT agreement may be referred to as an off-channel TWT SP or an off-channel TWT schedule. The off-channel TWT agreement can be used until the time indicated by the timeout interval element included in the channel use response frame transmitted by the AP MLD. The AP MLD may not transmit frames to the STA MLD on link(s) that are a pair of a link to which the off-channel TWT SP is applied and an NSTR link during the time corresponding to the off-channel TWT SP.

9A and 9B, the STA MLD may wish to terminate (e.g., release) the off-channel TWT agreement established by the exchange procedure of channel use request/response frames. To terminate the off-channel TWT agreement, the STA MLD may transmit a channel use request frame containing information indicating that the lifetime is 0 to the AP MLD. To distinguish off-channel TWT agreements, the dialog token subfield of the channel use request frame transmitted by the STA MLD is identical to the dialog token subfield of the channel use request/response frame exchanged to establish the off-channel TWT agreement. It can be set the same. The channel use request frame may include one or more TWT information elements. Each TWT information element may include a TWT flow ID that is subject to termination.

Alternatively, to terminate the off-channel TWT agreement, the STA MLD may transmit a channel use response frame to the AP MLD instead of a channel use request frame. The channel use response frame may include some or all of the information elements belonging to the channel use request frame. The AP MLD may receive a channel use request frame or a channel use response frame from the STA MLD, and may confirm that the lifetime is 0 based on the information contained in the received frame, and the TWT information element contained in the received frame. You can check (s) and/or dialog tokens. The AP MLD can confirm the off-channel TWT agreement for which the STA MLD requests termination, cancel the off-channel TWT SP(s) scheduled by the off-channel TWT agreement for which termination is requested, and further cancel the off-channel TWT SP(s) for which termination is requested. There may be no further scheduling.

In the embodiment of FIG. 9A, each of the channel use request frame and channel use response frame of the STA MLD may be transmitted on the first link or the second link. In the embodiment of FIG. 9B, each of the channel use request frame and the channel use response frame of the STA MLD may be transmitted on the first link, which is a link that is not an off channel (e.g., a link on which both the AP MLD and the STA MLD operate). .

FIG. 10A is a timing diagram illustrating a ninth embodiment of a direct communication scheduling method in a wireless LAN, and FIG. 10B is a timing diagram illustrating a 10th embodiment of a direct communication scheduling method in a wireless LAN.

Referring to FIGS. 10A and 10B, AP MLD and non-AP MLD (eg, STA MLD) may operate in multiple links. The STA MLD may perform direct communication (e.g., TDLS operation, TDLS communication) on a second link or a dedicated link for direct communication (e.g., off-channel, off-link). Off-channel and off-link may have the same meaning. The second link may be one link among multiple links in which AP MLD and STA MLD operate. An off-channel may be a dedicated channel (e.g., a dedicated link) for direct communication. A TDLS receiving STA (eg, TDLS receiver) that is the target of direct communication may operate in the second link or off channel. AP MLD may not operate in off-channel.

In the embodiment of FIG. 10A, the first link and the second link may be an NSTR link pair of the STA MLD. In the embodiment of FIG. 10B, the first link and the off channel may be an NSTR link pair of the STA MLD. STA MLD may be EMLSR STA MLD. The first link and the second link may be EMLSR links. Embodiments according to the present disclosure may be applied to EMLSR STA MLD (eg, EMLSR operation). For example, “if the STA MLD is an EMLSR STA MLD and the first link and the second link are EMLSR links,” the operation on the first link and the second link may be the same or similar to the operation on the NSTR link pair.

The STA MLD may transmit a channel use request frame to the AP MLD to perform direct communication. The AP MLD can receive a channel use request frame from the STA MLD and check the information element(s) included in the channel use request frame. The AP MLD may transmit a response frame to the channel use request frame to the STA MLD. A channel use request frame may be transmitted and received on the first link. The channel use request frame may include information on the channel and/or link that the STA MLD wishes to use (e.g., information on the second link, information on the off channel). In other words, the channel use request frame may include information on a channel and/or link through which the STA MLD directly communicates. The channel use request frame may include one or more target wake time (TWT) information elements (eg, TWT information, TWT element). The TWT information element may include a flow identifier (e.g., flow ID) that identifies the TWT request. A plurality of TWT information elements may include different TWT flow IDs. The TWT information element(s) included in the channel use request frame may indicate the TWT SP (e.g., off-channel TWT SP) with which the STA MLD wishes to perform direct communication.

The AP MLD may transmit a channel use response frame to the STA MLD in response to the channel use request frame. In other words, the AP MLD can determine the link and/or channel on which the STA MLD performs direct communication based on the information element(s) included in the channel use request frame, and the STA MLD's direct communication on the link and/or channel The TWT SP where communication is performed can be determined. The AP MLD may transmit to the STA MLD a channel usage response frame containing “information of the links and/or channels on which direct communication of the STA MLD is permitted” and/or “information of the TWT SP on which direct communication of the STA MLD is permitted.” there is. The STA MLD can receive a channel use response frame from the AP MLD and check the information element(s) included in the channel use response frame. The STA MLD may transmit a response frame for the channel use response frame to the AP MLD. The channel use response frame may include information about the channel and/or link requested by the STA MLD. In other words, the channel use response frame may include information on the channel and/or link through which the STA MLD directly communicates. The channel usage response frame may include one or more TWT information elements. In other words, the TWT information element(s) included in the channel use response frame may indicate the TWT SP (e.g., off-channel TWT SP, direct communication section) with which the STA MLD performs direct communication. The channel usage response frame may include a timeout interval element.

By exchanging channel use request/response frames containing TWT information element(s) between the STA MLD and the AP MLD, TWT settings (e.g., TWT agreement) for TDLS between the STA MLD and the AP MLD can be negotiated. TWT setup for TDLS may be referred to as off-channel TWT or off-channel TWT agreement. A TWT SP scheduled based on an off-channel TWT agreement may be referred to as an off-channel TWT SP or an off-channel TWT schedule. The off-channel TWT agreement can be used until the time indicated by the timeout interval element included in the channel use response frame transmitted by the AP MLD. The AP MLD may not transmit frames to the STA MLD on link(s) that are a pair of a link to which the off-channel TWT SP is applied and an NSTR link during the time corresponding to the off-channel TWT SP.

10A and 10B, the STA MLD may wish to terminate (e.g., release) the off-channel TWT agreement established by the exchange procedure of the channel use request/response frame. To terminate the off-channel TWT agreement, the STA MLD may transmit a TWT tear down frame to the AP MLD. The TWT teardown frame transmitted from the STA MLD to the AP MLD may include a TWT flow ID to distinguish the off-channel TWT agreement that the STA MLD wishes to terminate. The AP MLD may receive a TWT tear-down frame from the STA MLD and, based on the information contained in the TWT tear-down frame (e.g., TWT flow ID), may confirm the off-channel TWT agreement in which the STA MLD requests termination. there is. The AP MLD may cancel the off-channel TWT SP(s) scheduled by the off-channel TWT agreement for which termination is requested, and may no longer schedule the off-channel TWT SP(s).

The STA MLD may seek to adjust the off-channel TWT agreement established by the exchange procedure of channel use request/response frames. To coordinate off-channel TWT agreement, the STA MLD may transmit a TWT information frame to the AP MLD. The TWT information frame transmitted from the STA MLD to the AP MLD may include a TWT flow ID to distinguish the off-channel TWT agreement that the STA MLD wishes to coordinate. The AP MLD may receive a TWT information frame from the STA MLD, and may confirm the off-channel TWT agreement for which the STA MLD requests adjustment based on the information (e.g., TWT flow ID) included in the TWT information frame. The AP MLD can check the TWT parameters included in the TWT information frame and schedule the off-channel TWT SP based on the TWT parameter(s) requested by the STA MLD.

Figure 11 is a timing diagram showing an 11th embodiment of a direct communication scheduling method in wireless LAN.

Referring to FIG. 11, AP MLD and non-AP MLD (eg, STA MLD) can operate in multiple links. The STA MLD may perform direct communication (e.g., TDLS operation, TDLS communication) on the second link. The second link may be one link among multiple links in which AP MLD and STA MLD operate. Alternatively, the second link may be a dedicated channel (eg, dedicated link) for direct communication. A TDLS receiving STA (eg, TDLS receiver) that is the target of direct communication may operate on the second link. AP MLD may not operate in off-channel.

The first link and the second link may be an NSTR link pair of the STA MLD. STA MLD may be EMLSR STA MLD. The first link and the second link may be EMLSR links. Embodiments according to the present disclosure may be applied to EMLSR STA MLD (eg, EMLSR operation). For example, “if the STA MLD is an EMLSR STA MLD and the first link and the second link are EMLSR links,” the operation on the first link and the second link may be the same or similar to the operation on the NSTR link pair.

The STA MLD may transmit a channel use request frame to the AP MLD to perform direct communication. The AP MLD can receive a channel use request frame from the STA MLD and check the information element(s) included in the channel use request frame. The AP MLD may transmit a response frame to the channel use request frame to the STA MLD. A channel use request frame may be transmitted and received on the first link. The channel use request frame may include information on the channel and/or link that the STA MLD wishes to use (e.g., information on the second link, information on the off channel). In other words, the channel use request frame may include information on a channel and/or link through which the STA MLD directly communicates. Direct communication may be communication between STAs. The channel use request frame may include one or more TWT information elements (eg, TWT information, TWT element). The TWT information element may include a flow identifier (e.g., flow ID) that identifies the TWT request. The TWT information elements include “TWT information on channels and/or links that the STA MLD (e.g. STA) wishes to use” and “TWT information on channels and/or links on which transmission of the AP MLD (e.g. AP) is prohibited.” Information may be included.

The AP MLD may transmit a channel use response frame to the STA MLD in response to the channel use request frame. STA MLD can receive a channel use response frame from AP MLD. The STA MLD may transmit a response frame for the channel use response frame to the AP MLD. The channel use response frame may include information about the channel and/or link requested by the STA MLD. The channel usage response frame may include one or more TWT information elements. The TWT information elements of the Channel Usage Response frame include “TWT information on the channel and/or link that the STA MLD (e.g., STA) wishes to use” and “Channels and channels on which transmission of the AP MLD (e.g., AP) is prohibited and /or may include "TWT information" in the link. The channel usage response frame may include a timeout interval element.

By exchanging channel use request/response frames containing TWT information element(s) between the STA MLD and the AP MLD, TWT settings (e.g., TWT agreement) for TDLS between the STA MLD and the AP MLD can be negotiated. TWT setup for TDLS may be referred to as off-channel TWT or off-channel TWT agreement. A TWT SP scheduled based on an off-channel TWT agreement may be referred to as an off-channel TWT SP or an off-channel TWT schedule. While the STA MLD is performing TDLS communication, TWT establishment on a link in which the AP MLD is prohibited from transmitting frames to the STA MLD may be referred to as an on-channel TWT agreement. A TWT SP scheduled based on the on-channel TWT agreement may be referred to as an on-channel indication. Off-channel TWT agreement and on-channel TWT agreement can be used until the time indicated by the timeout interval element included in the channel use response frame transmitted by the AP MLD. The AP MLD may not transmit frames to the STA MLD on link(s) that are a pair of a link to which the off-channel TWT SP is applied and an NSTR link during the time corresponding to the off-channel TWT SP. The AP MLD may not transmit frames to the STA MLD on the link(s) to which the on-channel indication applies.

The operation of the method according to the embodiment of the present disclosure can be implemented as a computer-readable program or code on a computer-readable recording medium. Computer-readable recording media include all types of recording devices that store information that can be read by a computer system. Additionally, computer-readable recording media can be distributed across networked computer systems so that computer-readable programs or codes can be stored and executed in a distributed manner.

Additionally, computer-readable recording media may include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, or flash memory. Program instructions may include not only machine language code such as that created by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

Although some aspects of the disclosure have been described in the context of an apparatus, it may also refer to a corresponding method description, where a block or device corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may also be represented by corresponding blocks or items or features of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, programmable computer, or electronic circuit. In some embodiments, at least one or more of the most important method steps may be performed by such a device.

In embodiments, a programmable logic device (e.g., a field programmable gate array) may be used to perform some or all of the functionality of the methods described herein. In embodiments, a field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described herein. In general, it is desirable for the methods to be performed by some hardware device.

Although the present disclosure has been described above with reference to preferred embodiments, those skilled in the art may modify and change the present disclosure in various ways without departing from the spirit and scope of the present disclosure as set forth in the claims below. You will understand that it is possible.

Claims (20)

As a method of STA (station) MLD (multi-link device),
Transmitting a first frame requesting use of a link for direct communication to an access point (AP) MLD on a first link;
Receiving a second frame from the AP MLD on the first link in response to a request to use the link for direct communication; and
Comprising the step of performing the direct communication in a target wake time (TWT) service period (SP) of a second link established by an exchange procedure of the first frame and the second frame,
Method of STA MLD. In claim 1,
The first frame includes information on at least one of the second link or the TWT SP with which the STA MLD wishes to perform the direct communication,
Method of STA MLD. In claim 1,
The second frame includes information on at least one of the second link or the TWT SP for which the direct communication of the STA MLD is allowed,
Method of STA MLD. In claim 1,
The STA MLD method is,
Before the TWT SP, further comprising performing communication with the AP MLD at a transmit opportunity (TXOP) in one of the first link and the second link,
If the first link and the second link are a non-simultaneous transmit and receive (NSTR) link pair, the TXOP is set to end before MediumSyncDelay time from the start of the TWT SP, or the TXOP is set to end before the MediumSyncDelay time from the start of the TWT SP Terminates early before MediumSyncDelay time,
Method of STA MLD. In claim 1,
The STA MLD method is,
Before the TWT SP, further comprising performing communication with the AP MLD at a TXOP in one of the first link and the second link,
“If the first link and the second link are an NSTR link pair, and the STA MLD is an enhanced multi-link single radio (EMLSR) MLD,” the TXOP is “MediumSyncDelay time + EMLSR transition from the start of the TWT SP. (transition) time", or the TXOP is terminated early before the "MediumSyncDelay time + EMLSR transition time" from the start of the TWT SP,
Method of STA MLD. In claim 1,
During the time corresponding to the TWT SP of the second link, the STA MLD does not expect to receive a frame from the AP MLD on the first link that is a NSTR link pair with the second link.
Method of STA MLD. In claim 1,
If the first link and the second link are an NSTR link pair, the TWT SP is set to include a MediumSyncDelay time, and the direct communication is performed in the time remaining after the end of the MediumSyncDelay time within the TWT SP.
Method of STA MLD. In claim 1,
“If the first link and the second link are an NSTR link pair, and the TWT SP partially overlaps with the MediumSyncDelay time,” the direct communication is “a time that does not overlap with the MediumSyncDelay time within the TWT SP + the AP MLD carried out in “additional time allotted by”
Method of STA MLD. In claim 1,
The STA MLD method is,
When the direct communication is terminated, transmitting a third frame for early termination of the TWT SP; and
Further comprising early terminating the TWT SP after transmission of the third frame,
Method of STA MLD. As a method of an access point (AP) multi-link device (MLD),
Receiving a first frame requesting use of a link for direct communication from a STA (station) MLD on a first link;
determining a second link on which the direct communication is performed and a target wake time (TWT) and service period (SP) based on the information included in the first frame; and
Transmitting a second frame including information of the second link and information of the TWT SP to the STA MLD in the first link,
During the time corresponding to the TWT SP of the second link, the AP MLD does not communicate with the STA MLD on the first link, which is a non-simultaneous transmit and receive (NSTR) link pair with the second link.
Method of AP MLD. In claim 10,
The AP MLD method is,
Before the TWT SP, further comprising performing communication with the STA MLD at a transmit opportunity (TXOP) in one of the first link and the second link,
The TXOP is set to end before the MediumSyncDelay time from the start of the TWT SP, or the TXOP is terminated early before the MediumSyncDelay time from the start of the TWT SP,
Method of AP MLD. In claim 10,
The AP MLD method is,
Before the TWT SP, further comprising performing communication with the STA MLD at a TXOP in one of the first link and the second link,
If the STA MLD is an enhanced multi-link single radio (EMLSR) MLD, the TXOP is set to end before “MediumSyncDelay time + EMLSR transition time” from the start of the TWT SP, or the TXOP is set to end before the “MediumSyncDelay time + EMLSR transition time” terminated early before "MediumSyncDelay time + EMLSR transition time" from the start of
Method of AP MLD. In claim 10,
The AP MLD method is,
“If the first link and the second link are an NSTR link pair, and the TWT SP overlaps the MediumSyncDelay time,” further comprising allocating additional time to the STA MLD,
The direct communication of the STA MLD is performed at “a time that does not overlap with the MediumSyncDelay time within the TWT SP + additional time allocated by the AP MLD.”
Method of AP MLD. In claim 10,
The AP MLD method is,
Receiving a third frame for early termination of the TWT SP from the STA MLD; and
Further comprising early terminating the TWT SP after reception of the third frame,
Method of AP MLD. As a STA (station) MLD (multi-link device),
Contains at least one processor,
The at least one processor has the STA MLD,
Transmitting a first frame requesting use of a link for direct communication to an access point (AP) MLD on the first link;
receive a second frame from the AP MLD on the first link in response to a request to use the link for direct communication; and
causing the direct communication to be performed in a target wake time (TWT) service period (SP) of the second link established by an exchange procedure of the first frame and the second frame,
STA MLD. In claim 15,
The at least one processor has the STA MLD,
Further causing communication with the AP MLD at a transmit opportunity (TXOP) within one of the first link and the second link before the TWT SP,
If the first link and the second link are a non-simultaneous transmit and receive (NSTR) link pair, the TXOP is set to end before MediumSyncDelay time from the start of the TWT SP, or the TXOP is set to end before the MediumSyncDelay time from the start of the TWT SP Terminates early before MediumSyncDelay time,
STA MLD. In claim 15,
The at least one processor has the STA MLD,
further causing communication with the AP MLD at a TXOP in one of the first link and the second link, prior to the TWT SP,
“If the first link and the second link are an NSTR link pair, and the STA MLD is an enhanced multi-link single radio (EMLSR) MLD,” the TXOP is “MediumSyncDelay time + EMLSR transition from the start of the TWT SP. (transition) time", or the TXOP is terminated early before the "MediumSyncDelay time + EMLSR transition time" from the start of the TWT SP,
STA MLD. In claim 15,
If the first link and the second link are an NSTR link pair, the TWT SP is set to include a MediumSyncDelay time, and the direct communication is performed in the time remaining after the end of the MediumSyncDelay time within the TWT SP.
STA MLD. In claim 15,
“If the first link and the second link are an NSTR link pair, and the TWT SP partially overlaps with the MediumSyncDelay time,” the direct communication is “a time that does not overlap with the MediumSyncDelay time within the TWT SP + the AP MLD carried out in “additional time allotted by”
STA MLD. In claim 15,
The at least one processor has the STA MLD,
When the direct communication is terminated, transmitting a third frame for early termination of the TWT SP; and
further causing early termination of the TWT SP after transmission of the third frame,
STA MLD.

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