Method and apparatus for restricted target wake-up time operation for latency sensitive traffic in wireless local area networks

Abstract

Embodiments of the present invention provide a method and apparatus for Restricted Target Wake-Up Time (R-TWT) operation for latency-sensitive traffic in a WLAN. The method, performed by an access point (AP) in an AP MLD, includes: sending an R-TWT response from a first AP in the AP MLD to a first STA in a non-AP MLD to establish an R-TWT protocol on one or more links to which at least one traffic identifier (TID) of latency-sensitive traffic has been mapped; wherein the mapping of the at least one TID of the latency-sensitive traffic to the at least one link is established by the first access point AP sending a first response to the first STA to map the at least one TID of the latency-sensitive traffic to the at least one link established between the AP MLD and the non-AP MLD, wherein the AP MLD includes a plurality of APs and the non-AP MLD includes a plurality of non-AP STAs.

Description

[0001] Case Analysis This application is a divisional application of Chinese Patent Application No. 202180095207.X, which entered the Chinese national phase of PCT international patent application PCT / CN2021 / 089431, filed on April 23, 2021, and entitled "Method and apparatus for restricted target wake-up time operation for delay-sensitive traffic in a wireless local area network". Technical Field

[0002] This application relates to target wake time (TWT) mechanisms in wireless communications, and more specifically to methods and apparatus for restricted TWT (R-TWT) operation of delay-sensitive traffic in wireless local area networks (WLANs). Background Technology

[0003] The TWT mechanism was initially designed to manage activity within a Basic Service Set (BSS) via Scheduling Stations (STAs) to reduce STA wake-up times required for power management. The Institute of Electrical and Electronics Engineers (IEEE) 802.11be introduced Restricted-TWT (R-TWT), which, based on the TWT mechanism, provides more reliable and predictable latency for delay-sensitive traffic. Typically, the R-TWT mechanism is used for protected transmissions of delay-sensitive traffic. Each delay-sensitive traffic item has a corresponding Traffic Identifier (TID).

[0004] Furthermore, 802.11be defines a direction-based TID-to-link mapping mechanism for multiple links established between an AP multilink device (MLD) comprising multiple access points (APs) and a non-AP MLD comprising multiple non-AP STAs. After successfully establishing multiple links between the AP MLD and the non-AP MLDs, the TID-to-link mapping can be updated through negotiation between the AP MLD and the non-AP MLDs if necessary.

[0005] However, the existing 802.11be standard has not yet defined a mechanism for R-TWT operations to cooperate with TID-to-link mapping. This could lead to inconsistencies between the scenarios formed by R-TWT operations and TID-to-link mapping.

[0006] Therefore, it is desirable to provide an effective mechanism for the cooperation of R-TWT operation and TID-to-link mapping for latency-sensitive traffic in WLANs, especially in IEEE 802.11be EHT WLANs. Summary of the Invention

[0007] Embodiments of the present invention provide methods and apparatus for R-TWT operations for latency-sensitive traffic in WLANs. Utilizing the methods and apparatus proposed in the various embodiments of the present invention, R-TWT operations can be effectively coordinated with TID-to-link mapping to avoid any potential inconsistencies.

[0008] According to a first aspect of the present invention, various embodiments of the present invention provide a first method for performing R-TWT operation for latency-sensitive traffic in a WLAN on the AP side. The method may include: a first AP in an AP MLD sending a first response to a first STA in a non-AP MLD to map at least one TID of latency-sensitive traffic to at least one link established between the AP MLD and the non-AP MLD, wherein the AP MLD includes a plurality of APs and the non-AP MLD includes a plurality of non-AP STAs; and the first AP sending an R-TWT response to the first STA to establish an R-TWT protocol on any one or more of the at least one link to which at least one TID of latency-sensitive traffic has been mapped.

[0009] According to a second aspect of the invention, various embodiments of the invention provide a second method for performing R-TWT operations for delay-sensitive traffic in a WLAN at a STA. The method may include: receiving a first response from a first AP in an AP MLD at a first STA in a non-AP MLD to map at least one TID of the delay-sensitive traffic to at least one link established between the AP MLD and the non-AP MLD, wherein the AP MLD includes a plurality of APs and the non-AP MLD includes a plurality of non-AP STAs; and receiving an R-TWT response at the first STA to establish an R-TWT protocol on any one or more of the at least one link to which the at least one TID of the delay-sensitive traffic has been mapped.

[0010] According to a third aspect of the invention, various embodiments of the invention provide an AP for R-TWT operation of latency-sensitive traffic in a WLAN. The AP may include: a TID-to-link mapping unit configured to send a first response to a first STA in a non-AP MLD to map at least one TID of latency-sensitive traffic to at least one link established between the AP MLD and the non-AP MLD, wherein the AP MLD includes a plurality of APs, the plurality of APs including the aforementioned AP, and the non-AP MLD includes a plurality of non-AP STAs, the plurality of non-AP STAs including the first STA; and an R-TWT establishment unit configured to send an R-TWT response to the first STA to establish an R-TWT protocol on any one or more of the at least one link to which the at least one TID of latency-sensitive traffic has been mapped.

[0011] According to a fourth aspect of the invention, various embodiments of the invention provide a STA for R-TWT operation of latency-sensitive traffic in a WLAN. The STA may include: a TID-to-link mapping request unit configured to receive a first response from a first AP in an AP MLD to map at least one TID of latency-sensitive traffic to at least one link established between the AP MLD and a non-AP MLD, wherein the AP MLD includes a plurality of APs, including the first AP, and the non-AP MLD includes a plurality of non-AP STAs, including the aforementioned STA; and an R-TWT request unit configured to receive an R-TWT response from the first AP to establish an R-TWT protocol on any one or more of the at least one link to which at least one TID of latency-sensitive traffic has been mapped.

[0012] According to a fifth aspect of the present invention, various embodiments of the present invention provide an access point (AP) for R-TWT operation of delay-sensitive traffic in a WLAN. The AP may include: a memory for storing instructions for performing a first method of R-TWT operation of delay-sensitive traffic in a WLAN; and a processor communicatively coupled to the memory, the processor being configured to execute the instructions to perform the first method of R-TWT operation of delay-sensitive traffic in a WLAN as described in various embodiments of the present invention.

[0013] According to a sixth aspect of the present invention, various embodiments of the present invention provide a STA for R-TWT operation of delay-sensitive traffic in a WLAN. The STA may include: a memory for storing instructions for performing a second method of R-TWT operation of delay-sensitive traffic in a WLAN; and a processor communicatively coupled to the memory, the processor being configured to execute the instructions to perform the second method of R-TWT operation of delay-sensitive traffic in a WLAN as described in various embodiments of the present invention.

[0014] According to a seventh aspect of the present invention, various embodiments of the invention provide a computer program product. The computer program product includes instructions that, when executed on a computer, cause the computer to perform a first or second method of R-TWT operation for latency-sensitive traffic in a WLAN according to any embodiment of the present invention.

[0015] According to an eighth aspect of the invention, various embodiments of the invention provide a computer program including instructions that, when executed on a computer, cause the computer to perform a method for R-TWT operation for latency-sensitive traffic in a WLAN according to any embodiment of the invention.

[0016] According to a ninth aspect of the present invention, various embodiments of the present invention provide a chip configured to perform a method for R-TWT operation of latency-sensitive traffic in a WLAN according to any embodiment of the present invention. Attached Figure Description

[0017] The invention will be described in detail with reference to the accompanying drawings, in which: Figure 1 This is a flowchart illustrating a first method for R-TWT operation for latency-sensitive traffic in a WLAN, performed by a first AP according to various embodiments of the present invention.

[0018] Figure 2 This is a flowchart illustrating a second method for R-TWT operation for latency-sensitive traffic in a WLAN, performed by a first non-AP STA according to various embodiments of the present invention.

[0019] Figure 3A This is a schematic diagram illustrating a method for R-TWT operation for latency-sensitive traffic in a WLAN according to a first embodiment of the present invention.

[0020] Figure 3B This is a block diagram illustrating the format of R-TWT elements according to some embodiments of the present invention.

[0021] Figure 4 This is a schematic diagram illustrating a method for R-TWT operation for latency-sensitive traffic in a WLAN according to a second embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram illustrating a method for R-TWT operation for latency-sensitive traffic in a WLAN according to a third embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram illustrating a method for R-TWT operation for latency-sensitive traffic in a WLAN according to a fourth embodiment of the present invention.

[0024] Figure 7A This is a block diagram illustrating a first format of the broadcast R-TWT parameter set field of an R-TWT element having TID-to-link mapping information according to some embodiments of the present invention.

[0025] Figure 7B This is a block diagram illustrating a second format of the broadcast R-TWT parameter set field of an R-TWT element having TID-to-link mapping information according to some embodiments of the present invention.

[0026] Figure 7CThis is a block diagram illustrating a third format of the broadcast R-TWT parameter set field of an R-TWT element having TID-to-link mapping information according to some embodiments of the present invention.

[0027] Figure 8A This is a schematic diagram illustrating R-TWT operation using a silent element after R-TWT protocols have been established on multiple links according to an embodiment of the present invention.

[0028] Figure 8B This is a schematic diagram illustrating R-TWT operation of a link mapping element using a TID indicating a paused R-TWT operation mode after R-TWT protocols have been established on multiple links, according to an embodiment of the present invention.

[0029] Figure 8C This is a schematic diagram illustrating R-TWT operation of a TID to a link mapping element using an R-TWT operation mode indicating termination, after R-TWT protocols have been established on multiple links according to an embodiment of the present invention.

[0030] Figure 9 This is a block diagram illustrating the format of a TID-to-link mapping element of R-TWT information having a TIDx field according to some embodiments of the present invention.

[0031] Figure 10 This is a schematic diagram illustrating an AP according to some embodiments of the present invention.

[0032] Figure 11 This is a schematic diagram illustrating a STA according to some embodiments of the present invention. Detailed Implementation

[0033] In the following description, numerous specific details are set forth in order to provide a thorough understanding of various illustrative embodiments of the invention. However, those skilled in the art will understand that embodiments of the invention can be practiced without some or all of these specific details. It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention.

[0034] The embodiments described in the context of one of the methods or devices are equally effective for other methods or devices. Similarly, the embodiments described in the context of a method are equally effective for a device, and vice versa.

[0035] Features described in the context of one embodiment may be correspondingly applied to the same or similar features in other embodiments. Features described in the context of one embodiment may be correspondingly applied to other embodiments, even if not explicitly described in those other embodiments. Furthermore, additions and / or combinations and / or substitutions described for features in the context of one embodiment may be correspondingly applied to the same or similar features in other embodiments.

[0036] As used herein, the articles “a,” “an,” and “the” used with respect to features or elements include references to one or more features or elements. As used herein, the term “and / or” includes any and all combinations relating to one or more of the listed items. As used herein, the terms “first,” “second,” and “third,” etc., are used merely as labels and are not intended to impose numerical requirements on their objects. As used herein, the term “configured to” may be interchanged with “operate” or “adapted to.”

[0037] Various embodiments of the present invention provide mechanisms for coordinating the R-TWT protocol establishment process and R-TWT operations with TID-to-link mapping in a WLAN. R-TWT operations are provided to allow APs to use enhanced media access protection and resource reservation mechanisms to provide more predictable latency and reduce worst-case latency and / or jitter, resulting in higher reliability for latency-sensitive traffic. TID-to-link mapping is a direction-based TID-to-link mapping mechanism established between multiple links, including an AP MLD comprising multiple APs and a non-AP MLD comprising multiple non-AP STAs. Each TID is used by a higher-layer entity to distinguish Media Access Control (MAC) Service Data Units (MSDUs) to MAC entities supporting Quality of Service (QoS) within MAC data services.

[0038] Figure 1 This is a flowchart illustrating a first method 100 for R-TWT operation for latency-sensitive traffic in a WLAN, performed by a first AP according to various embodiments of the present invention. The first AP is an AP in an AP MLD that includes multiple APs, and a link can be established between the first AP and a first non-AP STA in a non-AP MLD that includes multiple non-AP STAs.

[0039] At box 101, the first AP receives the first request from the first STA.

[0040] At box 102, a first response is sent from the first AP to the first STA to map at least one TID of delay-sensitive traffic to at least one link established between the AP MLD and the non-AP MLD, wherein the AP MLD includes multiple APs and the non-AP MLD includes multiple non-AP STAs.

[0041] In embodiments of the present invention, the TID of delay-sensitive traffic is also referred to as LL TID.

[0042] At box 103, the first AP receives an R-TWT request from the first STA.

[0043] At box 104, the first AP sends an R-TWT response to the first STA to establish an R-TWT protocol on any one or more of the at least one link to which the at least one LL TID has been mapped.

[0044] Although in the first method 100, the first AP sends a first response upon receiving a first request from the first STA, it should be noted that in some embodiments, the first AP may send an unsolicited first response without receiving a first request to map at least one TID of latency-sensitive traffic to at least one link established between the AP MLD and a non-AP MLD. Furthermore, in the first method 100, the R-TWT protocol is established through two steps in blocks 103 and 104. However, it should be noted that in other embodiments, the R-TWT protocol for any one or more links to which at least one LL TID has been mapped can be established through an unsolicited R-TWT response from the first AP to the first STA. That is, the first AP may not receive an R-TWT request from the first STA, but may simply send an unsolicited R-TWT response to the first STA to establish the R-TWT protocol for any one or more links to which at least one LL TID has been mapped.

[0045] Figure 2 This is a flowchart illustrating a second method 200 for R-TWT operation for latency-sensitive traffic in a WLAN, performed by a first non-AP STA according to various embodiments of the present invention.

[0046] At box 201, the first STA sends the first request to the first AP.

[0047] At box 202, a first STA receives a first response from a first AP to map at least one LL TID to at least one link established between an AP MLD and a non-AP MLD, wherein the AP MLD includes multiple APs and the non-AP MLD includes multiple non-AP STAs.

[0048] At box 203, the first STA sends an R-TWT request to the first AP.

[0049] At box 204, the first STA receives an R-TWT response from the first AP to establish an R-TWT protocol on any one or more of the at least one link to which the at least one LL TID has been mapped.

[0050] Although in the second method 200, the first STA sends a first request to the first AP before receiving a first response from the first AP, it should be noted that in some embodiments, the first STA may receive only an unsolicited first response from the first AP without sending a first request to map at least one TID of latency-sensitive traffic to at least one link established between the AP MLD and a non-AP MLD. Furthermore, in the second method 200, the R-TWT protocol is established through two steps in blocks 103 and 104. However, it should be noted that in other embodiments, the R-TWT protocol for any one or more of the at least one link to which the at least one LL TID has been mapped can be established through an unsolicited R-TWT response from the first AP to the first STA. That is, the first STA may receive only an unsolicited R-TWT response from the first AP without sending an R-TWT request to establish the R-TWT protocol on any one or more of the at least one link to which the at least one LL TID has been mapped.

[0051] Multi-link establishment process using the default TID to link mapping In some embodiments, the TID-to-link mapping process can be a default process performed during or after the multi-link establishment process between the AP MLD and the non-AP MLD. In these embodiments, the first request received by the first AP can be a first multi-link association request from the first STA. The first response sent by the first AP can be a first multi-link association response, which is sent to the first STA to establish multiple links between the AP in the AP MLD and the STA in the non-AP MLD, and by default maps all TIDs to all of the multiple links established between the AP MLD and the non-AP MLD, wherein all TIDs include the at least one LL TID. In these embodiments, the R-TWT protocol can be established for any one or more links established between the AP MLD and the non-AP MLD.

[0052] Multi-link establishment process using TID to link mapping negotiation In some embodiments, TID-to-link mapping can be established during the multi-link establishment process via TID-to-link mapping negotiation; that is, negotiation can be included during the multi-link establishment process. In these embodiments, the first request received by the first AP may be a second multi-link association request from the first STA. The first response sent by the first AP may be a second multi-link association response, which is sent to the first STA to establish multiple links between the AP in the AP MLD and the STA not in the AP MLD, and to map at least one TID of latency-sensitive traffic to a subset of the links established between the AP MLD and the non-AP MLD through negotiation between the first STA and the first AP.

[0053] In these embodiments, the at least one LL TID can be mapped to a subset of links between the AP MLD and the non-AP MLD. Each TID can be mapped to the same set of links or different sets of links. In one example, the non-AP MLD can indicate during the multi-link establishment process (e.g., in a second multi-link association request sent from the first STA to the first AP) that the same set of links or different sets of links can be used for each TID. For example, the first STA can indicate in the second multi-link association request that the same set of links is used for all TIDs, or that all TIDs are mapped to all links established between the AP MLD and the non-AP MLD.

[0054] TID to Link Mapping Negotiation In some embodiments, after the multi-link establishment process, the TID-to-link mapping can be updated through negotiation between the AP MLD and non-AP MLD, for example, through negotiation between the first AP and the first STA. This negotiation can be initiated by the AP MLD or non-AP MLD based on uplink and downlink load, link status, and / or performance. Link status may include power-saving status. In one embodiment, the negotiation on the first AP side may include: the first AP receiving a TID-to-link mapping request from the first STA, and the first AP sending a TID-to-link mapping response to the first STA to map at least one LL TID to a link between the AP MLD and the non-AP MLD that has not yet been mapped. Correspondingly, the negotiation on the first STA side may include: the first STA sending a TID-to-link mapping request to the first AP, and the first STA receiving a TID-to-link mapping response from the first AP to map at least one TID of latency-sensitive traffic to a link between the AP MLD and the non-AP MLD that has not yet been mapped.

[0055] It should be noted that in some embodiments of the present invention, the TID to link mapping negotiation for all links established between AP MLD and non-AP MLD can be performed through the separate TID to link mapping negotiation process, rather than being performed together with the multi-link establishment process or as a default process that does not require negotiation.

[0056] In various embodiments, the R-TWT protocol establishment process (i.e., the process of establishing an R-TWT protocol on any one or more links of at least one link to which at least one LL TID has been mapped) is performed through negotiation between the AP MLD and the non-AP MLD (e.g., negotiation between the first AP and the first STA). During the negotiation process, the first AP receives an R-TWT request from the first STA; the first AP sends a first R-TWT response to the first STA to establish an R-TWT protocol on any one or more links of at least one LL TID to which at least one LL TID has been mapped. In one example, if there are two links between the AP MLD and the non-AP MLD, link 1 is established between the first AP and the first STA, and link 2 is established between the second AP and the second STA, then negotiation can be performed between the first AP and the first STA to establish an R-TWT protocol on link 1, or link 2, or both. The R-TWT protocols established for link 1 and link 2 may have the same or different start times, end times, and other parameters.

[0057] In some embodiments, an R-TWT request from a first STA and / or an R-TWT response from a first AP may include an R-TWT element, which includes a first subfield and a second subfield in a control field, wherein the first subfield is configured to indicate whether the information included in the R-TWT element is used for negotiation of R-TWT parameters, and the second subfield is configured to indicate whether the information included in the R-TWT element applies to all links to which at least one TID of latency-sensitive traffic has been mapped.

[0058] The R-TWT establishment process integrates TID-to-link mapping negotiation. In some embodiments, the TID-to-link mapping process and the R-TWT establishment process can be performed together through negotiation between the AP MLD and the non-AP MLD (e.g., negotiation between the first AP and the first STA). The negotiation on the first AP side may include: the first AP receiving an integrated R-TWT request from the first STA, and the first AP sending an integrated R-TWT response to the first STA to map at least one TID of latency-sensitive traffic to at least one link between the AP MLD and the non-AP MLD to which at least one LLTID has not yet been mapped, and to establish an R-TWT protocol on any one or more of the at least one link to which the at least one LLTID has been mapped.

[0059] Accordingly, the negotiation on the first STA side may include: the first STA sending an integrated R-TWT request to the first AP, and the first STA receiving an integrated R-TWT response from the first AP, to map at least one TID of delay-sensitive traffic to at least one link between the AP MLD and a non-AP MLD to which the at least one LL TID has not yet been mapped, and to establish an R-TWT protocol on any one or more of the at least one link to which the at least one LL TID has been mapped.

[0060] It should be noted that in some embodiments, all TID-to-link mapping negotiations between the AP MLD and non-AP MLD can be performed through this integration process, or only this negotiation process can be performed to establish a TID-to-link mapping for a specific link after TID-to-link mappings for multiple links between the AP MLD and non-AP MLD have been established during the multi-link establishment process.

[0061] In some embodiments, an integrated R-TWT request may include a first R-TWT element configured to indicate at least one link on which an R-TWT protocol is to be established and at least one link to which at least one LL TID will be mapped. In some embodiments, an integrated R-TWT response may include a second R-TWT element configured to indicate one or more links on which an R-TWT protocol has already been established and at least one link to which at least one LL TID has been mapped. Preferably, the R-TWT element may be included in both the second R-TWT request and the second R-TWT response.

[0062] In some embodiments, an integrated R-TWT request and / or integrated R-TWT response may be configured to include at least one first R-TWT element and at least one TID-to-link mapping element, wherein the at least one first R-TWT element indicates at least one link on which an R-TWT protocol is established, for example, at least one link on which an R protocol is to be established or has already been established, and the at least one TID-to-link mapping element indicates at least one link on which at least one TID of latency-sensitive traffic is mapped, for example, at least one LL TID to which at least one link is to which at least one LL TID is to be mapped or has already been mapped.

[0063] Alternatively, in some embodiments, the integrated R-TWT request and / or integrated R-TWT response may be configured to include at least one second R-TWT element, which indicates one or more links on which the R-TWT protocol is established and at least one link to which at least one TID of latency-sensitive traffic is mapped. In a first example, the second R-TWT element may include a broadcast R-TWT parameter set field configured to include a first subfield (e.g., a link ID bitmap field), a second subfield (e.g., a link mapping for downlink TIDs), and a third subfield (e.g., a link mapping for uplink TIDs), the first subfield indicating at least one link on which R-TWT is applied, the second subfield indicating at least one link on which frames belonging to the TID of downlink latency-sensitive traffic are transmitted, and the third subfield indicating at least one link on which frames belonging to the TID of uplink latency-sensitive traffic are transmitted. In the second example, the second R-TWT element may include a broadcast R-TWT parameter set field, which is configured to include a subfield for R-TWT from the R-TWT traffic information field, link ID bitmap field, and request type field. For example, it may be configured to indicate whether the TWT scheduling specified by the corresponding broadcast R-TWT parameter set field is an R-TWT subfield of the R-TWT scheduling. In the third example, the second R-TWT element is the same as in the second example, except that in the third example, the broadcast R-TWT parameter set field includes two link ID bitmap fields, for example, a link ID bitmap field for UL TID and a link ID bitmap field for DL ​​TID.

[0064] R-TWT Operations After the R-TWT Setup Process In some embodiments, the method may further include: if a TID of no latency-sensitive traffic is mapped to a first link established between a first AP and a first STA due to a TID-to-link mapping update / change, the R-TWT protocol established on the first link will be torn down by the first AP and the first STA. For example, the R-TWT protocol can be torn down through a termination procedure comprising: the first AP sending a TID-to-link mapping element with an R-TWT termination mode indication on the first link to terminate the R-TWT protocol on the first link. Accordingly, the first STA tore down the R-TWT protocol on the first link upon receiving the TID-to-link mapping element with an R-TWT termination mode indication sent on the first link. This termination procedure can be performed when the AP MLD and non-AP MLD do not support or enter a suspended R-TWT operation mode.

[0065] In some embodiments, when the AP MLD and non-AP MLD support a suspended R-TWT operation mode, the first method 100 at the first AP may further include: if no delay-sensitive traffic TID is mapped to the first link established between the first AP and the first STA, the first AP may send an R-TWT SP silence element or a TID with a suspended R-TWT mode indication to a link mapping element on the first link to put the first link into a suspended R-TWT operation mode; or, the first AP may send a TID with an R-TWT termination mode indication to a link mapping element on the first link to terminate the R-TWT protocol on the first link.

[0066] Accordingly, the second method 200 at the first STA may further include: when a TID without delay-sensitive traffic is mapped to the first link established between the first AP and the first STA, the first STA receives an R-TWT SP silencing element or a TID-to-link mapping element with a suspended R-TWT mode indication sent by the first AP on the first link, and the first STA causes the first link to enter a suspended R-TWT operation mode; or, when the first STA receives a TID-to-link mapping element with an R-TWT termination mode indication, it causes the R-TWT protocol on the first link to enter an R-TWT termination mode. Preferably, the first method 100 and the second method 200 may further include: when the first link enters the suspended R-TWT operation mode, if the duration of the suspended R-TWT operation mode exceeds a predetermined threshold, the R-TWT protocol on the first link may be terminated.

[0067] In some embodiments, the TID to link mapping element may include an R-TWT information field for the TID, which is set to indicate whether at least one TID of delay-sensitive traffic is mapped to multiple links established between an AP MLD and a non-AP MLD, and the status of the R-TWT operation, wherein the R-TWT operation status is set to indicate a suspended R-TWT operation mode, an R-TWT termination mode, or a non-existent R-TWT mode.

[0068] It should be noted that the R-TWT protocol establishment process in various embodiments of the present invention may further include establishing membership for non-AP STAs in the non-AP MLD in the broadcast TWT after an R-TWT protocol has been established between the non-AP MLD and the AP MLD. Some embodiments of the present invention will be described below to illustrate methods for R-TWT operation for latency-sensitive traffic in a WLAN according to various embodiments of the present invention. It should be noted that these embodiments are provided for illustrative purposes only and are not intended to limit the scope of the invention.

[0069] First embodiment (multi-link establishment using default TID to link mapping) Figure 3A This is a schematic diagram illustrating a method 300 for R-TWT operation for latency-sensitive traffic in a WLAN according to a first embodiment of the present invention. In this embodiment, the AP MLD includes three APs, namely AP1, AP2, and AP3, and the non-AP MLD includes three non-AP STAs, namely STA1, STA2, and STA3. As shown in FIG3, method 300 includes the following steps: Step 301: STA1 sends a first multi-link association request to AP1 to request the establishment of multiple links between AP MLD and non-AP MLD. In this embodiment, the multiple links between AP MLD and non-AP MLD include link 1 between AP1 and STA1, link 2 between AP2 and STA2, and link 3 between AP3 and STA3.

[0070] Step 302: After receiving the first multi-link association request, AP1 sends the first multi-link association response to AP1 to establish link 1, link 2 and link 3.

[0071] Step 303: All TIDs are mapped to all links established between AP MLD and non-AP MLD, namely, link 1, link 2 and link 3.

[0072] Steps 301 and 302 are executed to establish Link 1 between AP1 and STA1, Link 2 between AP2 and STA2, and Link 3 between AP3 and STA3. This is the multi-link establishment process in this embodiment. Although AP1 and STA1 are used for the multi-link establishment process in this embodiment, those skilled in the art will understand that AP2 and STA2, or AP3 and STA3, can also be used for the multi-link establishment process in other embodiments. In this embodiment, the mapping of TIDs to links is a default process performed after the multi-link establishment process. In this default process, all TIDs, including at least one TID of latency-sensitive traffic, are mapped to all links established between AP MLDs and non-AP MLDs, i.e., Link 1, Link 2, and Link 3 in this embodiment.

[0073] Step 304: STA1 sends an R-TWT request to AP1 to request the establishment of the R-TWT protocol on all links established between AP MLD and non-AP MLD.

[0074] Step 305: After receiving the R-TWT request from STA1, AP1 sends an R-TWT response to STA1 to establish the R-TWT protocol on all links established between APMLD and non-AP MLD.

[0075] Step 306: Establish the R-TWT protocol on all links established between AP MLD and non-AP MLD (i.e., link 1, link 2 and link 3 in this embodiment).

[0076] It should be noted that although the R-TWT protocol is established on all links between the AP MLD and non-AP MLD in this embodiment, in other embodiments, the R-TWT protocol can be established on any one or more links between the AP MLD and non-AP MLD.

[0077] In the first embodiment, the R-TWT request and / or R-TWT response may include one or more R-TWT elements configured to indicate whether an R-TWT protocol is established on all links between the AP MLD and the non-AP MLD.

[0078] Figure 3B This is a block diagram illustrating the format of R-TWT elements according to some embodiments of the present invention. Figure 3BAs shown, the control fields of the R-TWT element include a Restricted TWT (R-TWT) indicator subfield and an applied link indicator subfield. The R-TWT indicator subfield is set to indicate whether the information included in the element is used for negotiating R-TWT parameters. For example, the R-TWT indicator subfield can be set to 1 to indicate that the information is used for R-TWT, or set to 0 to indicate that the information is not used for R-TWT. In this embodiment, the applied link indicator subfield can be set to indicate whether the information included in the element is to be applied to all links established between AP MLD and non-AP MLD. Alternatively, the applied link indicator subfield can be set to indicate whether the information included in the element is to be applied to all links to which at least one TID of latency-sensitive traffic has been mapped. For example, the applied link indicator subfield can be set to 1 to indicate "yes," that is, the information will be applied to all links to which at least one TID of latency-sensitive traffic has been mapped, or set to 0 to indicate "no," that is, the information will not be applied to all links to which at least one TID of latency-sensitive traffic has been mapped. It should be noted that in other embodiments, the R-TWT indicator subfield and the application link subfield in the control field of the R-TWT element may have different names.

[0079] Second embodiment (multi-link establishment using TID to link mapping negotiation) Figure 4 This is a schematic diagram illustrating a method 400 for R-TWT operation for latency-sensitive traffic in a WLAN according to a second embodiment of the present invention. In this embodiment, the AP MLD includes three APs, namely AP1, AP2, and AP3, and the non-AP MLD includes three non-AP STAs, namely STA1, STA2, and STA3. Figure 4 As shown, method 400 includes the following steps: Step 401: STA1 sends a second multi-link association request to AP1 to request the establishment of multiple links between AP MLD and non-AP MLD. In this embodiment, the multiple links include link 1 between AP1 and STA1, link 2 between AP2 and STA2, and link 3 between AP3 and STA3.

[0080] Step 402: After receiving the multi-link association request, AP1 sends a second multi-link association response to AP1 to establish link 1, link 2 and link 3.

[0081] Step 403: The TID of latency-sensitive traffic is mapped to Link 1 and Link 2. In this embodiment, more than one TID of latency-sensitive traffic is mapped to Link 1 and Link 2.

[0082] Step 404: STA1 sends an R-TWT request to AP1 to request the establishment of the R-TWT protocol on Link 1 and Link 2.

[0083] Step 405: After receiving the R-TWT request from STA1, AP1 sends an R-TWT response to STA1 to establish the R-TWT protocol on Link 1 and Link 2.

[0084] Step 406: Establish the R-TWT protocol on Link 1 and Link 2.

[0085] In the second embodiment, steps 401 and 402 are performed to establish multiple links between the AP MLD and the non-AP MLD. This multi-link establishment process is the same as in the first embodiment. In this embodiment, the TID-to-link mapping is a negotiation process performed concurrently with the multi-link establishment process. After this negotiation process, at least one TID of latency-sensitive traffic is mapped only to Link 1 and Link 2 of all links established between the AP MLD and the non-AP MLD.

[0086] In the second embodiment, the R-TWT protocol is established on all links (i.e., link 1 and link 2) to which at least one TID of the latency-sensitive traffic has been mapped. It should be noted that in other embodiments, the R-TWT protocol may be mapped to only link 1 or link 2.

[0087] In the second embodiment, the R-TWT request and / or R-TWT response may include one or more R-TWT elements configured to indicate whether an R-TWT protocol is established on all links to which at least one TID of latency-sensitive traffic has been mapped. The format of the R-TWT element may be as follows: Figure 3B As shown. The control fields of the R-TWT element include the R-TWT indicator subfield and the application link subfield. The R-TWT indicator subfield is set to indicate whether the information included in the element is used for negotiating R-TWT parameters (e.g., the parameters shown in the R-TWT parameter set field of the R-TWT element). For example, the R-TWT indicator subfield can be set to 1 to indicate that the information is used for R-TWT, or set to 0 to indicate that the information is not used for R-TWT. The application link indicator subfield can be set to indicate whether the information included in the element is to be applied to all links to which at least one TID of latency-sensitive traffic has been mapped. For example, the application link indicator subfield can be set to 1 to indicate that the information will be applied to all links to which at least one TID of latency-sensitive traffic has been mapped, or set to 0 to indicate that the information will not be applied to all links to which at least one TID of latency-sensitive traffic has been mapped.

[0088] Third embodiment (separate TID to link mapping) Figure 5 This is a schematic diagram illustrating a method 500 for R-TWT operation for latency-sensitive traffic in a WLAN according to a third embodiment of the present invention. In this embodiment, the AP MLD includes three APs, namely AP1, AP2, and AP3, and the non-AP MLD includes three non-AP STAs, namely STA1, STA2, and STA3. Figure 5 As shown, method 500 includes the following steps: Steps 501 to 503 are the same as steps 401 to 403, respectively. They will not be repeated here.

[0089] Step 504, STA1 sends a TID to link mapping request to request that at least one TID of latency-sensitive traffic be mapped to link 3.

[0090] Step 505: After receiving the TID to link mapping request, AP1 sends a TID to link mapping response to STA1 to map at least one TID of latency-sensitive traffic to link 3.

[0091] Step 506: The TID of latency-sensitive traffic is mapped to link 3. It should be noted that in this embodiment, multiple TIDs for latency-sensitive traffic are mapped to link 3.

[0092] Step 507: STA1 sends an R-TWT request to AP1 to request the establishment of the R-TWT protocol on all links to which at least one TID of the delay-sensitive traffic has been mapped. In this embodiment, the links include link 1, link 2, and link 3.

[0093] Step 508: After receiving the first R-TWT request from STA1, AP1 sends an R-TWT response to STA1 to establish the R-TWT protocol on Link 1, Link 2 and Link 3.

[0094] Step 509: Establish the R-TWT protocol on Link 1, Link 2, and Link 3.

[0095] Similar to the second embodiment, in the third embodiment, after the TID-to-link mapping negotiation, at least one LL TID is mapped to only links 1 and 2, and no LL TID is mapped to link 3. However, STA1 initiates a TID-to-link mapping update negotiation to establish a mapping from at least one LL TID to link 3. After mapping at least one LL TID to link 3, an R-TWT protocol establishment process is performed to establish the R-TWT protocol on all links to which at least one LL TID has been mapped.

[0096] Similar to the second embodiment, in the third embodiment, the R-TWT request and / or R-TWT response may include one or more R-TWT elements configured to indicate whether an R-TWT protocol is established on all links to which at least one LL TID has been mapped. The format of the R-TWT element may be as follows: Figure 3B As shown.

[0097] Fourth Implementation (R-TWT Establishment Integrated with TID to Link Mapping Negotiation) Figure 6 This is a schematic diagram illustrating a method 600 for R-TWT operation for latency-sensitive traffic in a WLAN according to a fourth embodiment of the present invention. In this embodiment, the AP MLD includes three APs, namely AP1, AP2, and AP3, and the non-AP MLD includes three non-AP STAs, namely STA1, STA2, and STA3. Figure 5 As shown, method 600 includes the following steps: Steps 601 to 603 are the same as steps 401 to 403, respectively. They will not be repeated here. In this embodiment, Link 1, Link 2, and Link 3 are established during the multi-link establishment process, and through TID-to-link mapping negotiation, at least one LLTID is mapped to only Link 1 and Link 2. No LLTID is mapped to Link 3.

[0098] Step 604, STA1 sends an integration R-TWT request to AP1 to request that at least one LL TID be mapped to link 3, and to request that the R-TWT protocol be established on link 1, link 2 and link 3.

[0099] Step 605: After receiving the integrated R-TWT request from STA1, AP1 sends an integrated R-TWT response to STA1 to map the TID of latency-sensitive traffic to link 3 and establish the R-TWT protocol on link 1, link 2 and link 3.

[0100] Step 606: Establish the R-TWT protocol on Link 1, Link 2 and Link 3.

[0101] Unlike the embodiments described above, in this embodiment, the TID-to-link mapping negotiation for link 3 is integrated with the R-TWT protocol establishment process. To perform TID-to-link mapping negotiation together with the R-TWT protocol establishment process, the integrated R-TWT request and integrated R-TWT response can be configured to include one or more R-TWT elements and TID-to-link mapping elements. Alternatively, the integrated R-TWT request and integrated R-TWT response can be configured to include one or more R-TWT elements, wherein each R-TWT element is configured to include one or more TID-to-link mapping subfields.

[0102] In one example, an integrated R-TWT request can be configured to include an R-TWT element that indicates not only the link on which an R-TWT protocol should be established, but also the link to which the TID of latency-sensitive traffic will be mapped. Upon receiving the integrated R-TWT request, AP1 determines whether to establish the requested TID-to-link mapping for link 3, and whether to establish an R-TWT protocol on the requested links (i.e., links 1, 2, and 3 in this embodiment), and sends an integrated R-TWT response to STA1. The integrated R-TWT response can be configured to include an R-TWT element that, for example, indicates, by accepting a TWT value, the link to which the TID of latency-sensitive traffic has been mapped and to which an R-TWT protocol has been established.

[0103] Figure 7A This is a block diagram illustrating a first format of the broadcast R-TWT parameter set field of an R-TWT element having TID-to-link mapping information according to some embodiments of the present invention. Figure 7A As shown, the broadcast R-TWT parameter set field is set to include a link ID bitmap subfield, a link mapping subfield for downlink TID, and a link mapping subfield for uplink TID.

[0104] The Link ID bitmap subfield is set to indicate at least one link on which the R-TWT element is applied. Each bit position in the Link ID bitmap subfield corresponds to the Link ID associated with the link. Each bit position can be set to indicate whether the R-TWT element is applied to the associated link. For example, bit position m in the Link ID bitmap subfield corresponds to Link ID m. Bit position m can be set to "1" to indicate that the R-TWT element is applied to the link associated with Link ID m, or set to "0" to indicate that the R-TWT element is not applied to the link associated with Link ID m. If the Link ID bitmap subfield is not present in the Broadcast R-TWT Parameter field, the link on which the R-TWT element is applied is the link on which the R-TWT element is transmitted.

[0105] The link mapping subfield of a downlink TID (e.g., TID i) can be set to indicate at least one link on which frames of TID i belonging to downlink delay-sensitive traffic are transmitted. Each bit position of the link mapping subfield of the downlink TID i can correspond to a link ID associated with the link. For example, bit position m of the link mapping subfield of the downlink TID i corresponds to link ID m. Bit position m can be set to "1" to indicate that TID i is mapped to a downlink link associated with link ID m, or set to "0" to indicate that TID i is not mapped to a downlink link associated with link ID m.

[0106] The link mapping subfield of an uplink TID (e.g., TID i) can be set to indicate the link on which frames of TID i belonging to uplink delay-sensitive traffic are transmitted. Each bit position of the link mapping subfield of the uplink TID i can correspond to a link ID associated with that link. For example, bit position m of the link mapping subfield of the uplink TID i corresponds to link ID m. Bit position m can be set to "1" to indicate that TID i is mapped to the uplink link associated with link ID m, or set to "0" to indicate that TID i is not mapped to the uplink link associated with link ID m.

[0107] Figure 7B This is a block diagram illustrating a second format of the broadcast R-TWT parameter set field of an R-TWT element having TID-to-link mapping information according to some embodiments of the present invention. Figure 7B As shown, in the second format, the request type field of the broadcast R-TWT parameter set field includes an R-TWT subfield, which is set to indicate whether the TWT schedule specified by the corresponding broadcast R-TWT parameter set field is an R-TWT schedule. For example, the R-TWT subfield can be set to 1 to indicate that the TWT schedule specified by the corresponding broadcast R-TWT parameter set field is an R-TWT schedule, otherwise it is set to 0. The broadcast R-TWT parameter set field also includes a link ID bitmap field and an R-TWT traffic information field.

[0108] In this example, the Link ID bitmap is a field of the Broadcast TWT Parameter Set field. Alternatively, in other embodiments of the invention, the Link ID bitmap may be a subfield of the R-TWT Traffic Information field. The Link ID bitmap field is set to indicate at least one link to which the R-TWT element is applied. A value of 1 in bit position m of the Link ID field can indicate that the link associated with Link ID m is the link to which the R-TWT element is applied. A value of 0 in bit position m of the Link ID field can indicate that the link associated with Link ID m is not the link to which the TWT element is applied. If the Link ID bitmap field is not present in the Broadcast TWT Parameter Set field, then the link to which the R-TWT element is applied is the link on which the R-TWT element is transmitted.

[0109] The R-TWT DL / UL TID bitmap subfield in the R-TWT Traffic Information field is set to indicate which TID(s) are identified by the TWT-scheduled AP or TWT-scheduled STA as a delay-sensitive traffic flow in the downlink direction on the link indicated in the Link ID bitmap subfield. The Restricted TWT UL TID bitmap subfield is set to indicate which TID(s) are identified by the TWT-scheduled AP or TWT-scheduled STA as a delay-sensitive traffic flow in the uplink direction on the link indicated in the Link ID bitmap subfield. A value of 1 or 0 at bit position k in the bitmap can be set to indicate that TID k is classified as a delay-sensitive traffic flow and that the MSDU of TID k is allowed / disallowed to be transmitted on the link indicated in the Link ID bitmap subfield in one or more R-TWT SPs indicated by the TWT element.

[0110] Figure 7C This is a block diagram illustrating a third format of the broadcast R-TWT parameter set field of an R-TWT element having TID-to-link mapping information according to some embodiments of the present invention. Figure 7C As shown, in the third format, the request type field of the broadcast R-TWT parameter set field includes an R-TWT subfield, which is related to... Figure 7B The R-TWT subfields in the second example shown are the same. The broadcast R-TWT parameter set fields also include the UL TID link ID bitmap field, the DL TID link ID bitmap field, and the R-TWT traffic information field.

[0111] The DL TID link ID bitmap is in this third format, such as Figure 7CThe fields shown are from the Broadcast TWT Parameter Set field. Alternatively, in other embodiments, it can be a subfield of the Restricted TWT Traffic Information field. The Link ID Bitmap field of the DL TID is set to indicate at least one link to which one or more DL TIDs are mapped. A value of 1 in bit position m of the Link Bitmap field of the DL TID can indicate that the link associated with Link ID m is the link to which one or more DL TIDs are mapped. A value of 0 in bit position m of the Link Bitmap field of the DL TID can indicate that the link associated with Link ID m is not the link to which one or more DL TIDs are mapped.

[0112] Similarly, the UL TID link ID bitmap is in this third format, such as... Figure 7C The fields shown are from the Broadcast TWT Parameter Set field. Alternatively, in other embodiments, it can be a subfield of the Restricted TWT Traffic Information field. The Link ID Bitmap field of the UL TID can be set to indicate that one or more UL TIDs are mapped to at least one link. A value of 1 in bit position m of the Link Bitmap field of the UL TID can indicate that the link associated with Link ID m is a link to which one or more UL TIDs are mapped. A value of 0 in bit position m of the Link Bitmap field of the UL TID can indicate that the link associated with Link ID m is not a link to which one or more UL TIDs are mapped.

[0113] The R-TWT DL TID bitmap subfield in the R-TWT Traffic Information field can be set to indicate which TID(s) is a delay-sensitive traffic flow in the downlink direction on the link indicated by the Link ID bitmap field of the DL TID (TWT-scheduled AP or STA). A value of 1 or 0 at bit position k in this bitmap indicates that TID k is classified as a delay-sensitive traffic flow and that the MSDU of TID k is allowed or not allowed to be transmitted on one or more restricted TWT SPs specified by the TWT element on the link indicated by the Link ID bitmap field of the DL TID.

[0114] The R-TWT UL TID bitmap subfield in the R-TWT Traffic Information field can be set to indicate which TID(s) is a delay-sensitive traffic flow in the uplink direction on the link indicated by the Link ID bitmap subfield of the UL TID, which is identified by the TWT-scheduled AP or the TWT-scheduled STA. A value of 1 or 0 at bit position k in this bitmap indicates that TID k is classified as a delay-sensitive traffic flow and that the MSDU of TID k is allowed or not allowed to be transmitted in one or more restricted TWT SPs specified by the TWT element on the link indicated by the Link ID bitmap field of the UL TID.

[0115] Those skilled in the art will understand that, in other embodiments of the present invention, if AP1 does not accept the request for TID-to-link mapping, the requested TID-to-link mapping may not be established, and accordingly, based on AP1's decision, the R-TWT protocol may be established only on one or more requested links.

[0116] In some embodiments of the present invention, after the R-TWT protocol has been successfully established on at least one link between an AP MLD and a non-AP MLD, it may be found that due to TID to link mapping updates / changes, no LL TID is mapped to one or more links on which the R-TWT protocol has been established. Figures 8A to 8C Three possible ways to perform R-TWT operations in these scenarios according to some embodiments of the present invention are shown.

[0117] R-TWT SP Silent Element Figure 8A This is a schematic diagram illustrating R-TWT operation using silent elements after R-TWT protocols have been established on multiple links according to an embodiment of the present invention. In this embodiment, neither the AP MLD nor the non-AP MLD supports the paused R-TWT operation mode. In this embodiment, AP1, AP2, and AP3 in the AP MLD are EHT APs, while the non-AP STAs in the non-AP MLD can be EHT STAs or pre-EHT STAs.

[0118] Reference Figure 8A The R-TWT protocol has been established on three links (i.e., link 1, link 2, and link 3) between the AP MLD and the non-AP MLD. When no LL TID is mapped to link 1 due to a TID-to-link mapping update / change, AP1 sends / broadcasts an R-TWT SP silence element on link 1 to announce the R-TWT SP silence interval. During the R-TWT SP silence interval, the R-TWT SP is ignored. Figure 8A As shown, two R-TWT SP silencing elements are sent on link 1. Similarly, in this embodiment, due to the TID-to-link mapping update, no LL TID is mapped to link 3, and AP3 sends three R-TWT SP silencing elements on link 3. The R-TWT SP silencing elements can be included in the management (MGMT) frames sent from AP1 / AP3 to STA1 / STA3. STA1 and STA3 receive the R-TWT SP silencing elements and will ignore R-TWT SPs that overlap with the R-TWT SP silencing interval. Furthermore, if the duration of the R-TWT silencing interval on the link exceeds a predetermined threshold, the R-TWT protocol on that link can be terminated.

[0119] Paused R-TWT operation mode Figure 8B This is a schematic diagram illustrating R-TWT operation using a TID-to-link mapping element indicating a suspended R-TWT mode, after R-TWT protocols have been established on multiple links, according to an embodiment of the present invention. In this embodiment, both APMLD and non-AP MLD support the suspended R-TWT operation mode. In this embodiment, AP1, AP2, and AP3 in the AP MLD are EHTAPs, while the non-AP STAs in the non-AP MLD can be EHT STAs or pre-EHT STAs.

[0120] Reference Figure 8B The R-TWT protocol has been established on three links (i.e., link 1, link 2, and link 3) between the AP MLD and the non-AP MLD. When no LL TID is mapped to link 1 due to a TID-to-link mapping update / change, AP1 sends / broadcasts a TID-to-link mapping element with a paused R-TWT mode indication on link 1 to announce the updated TID mapped to link 1. The TID-to-link mapping element with a paused R-TWT mode indication can be included in the MGMT frame transmitted from AP1 to STA1 on link 1. In this embodiment, two TID-to-link mapping elements are transmitted on link 1. Similarly, in this embodiment, since there is no LL TID mapped to link 3 due to a TID-to-link mapping update, AP3 sends three TID-to-link mapping elements on link 3.

[0121] Once STA1 and STA3 receive TID-to-link mapping elements with a paused R-TWT mode indication on Link 1 and Link 3 respectively, the R-TWT SP will be ignored during the valid time interval of the updated TID-to-link mapping indicated in the TID-to-link mapping element. Furthermore, if the duration of the updated TID-to-link mapping indicated in the TID-to-link mapping element on the link exceeds a predetermined threshold, the R-TWT protocol on that link can be terminated.

[0122] Termination of R-TWT operation mode Figure 8C This is a schematic diagram illustrating R-TWT operation of a TID-to-link mapping element using an indicated termination R-TWT operation mode after R-TWT protocols have been established on multiple links, according to an embodiment of the present invention. In this embodiment, both AP MLDs and non-AP MLDs support a suspended R-TWT operation mode. In this embodiment, AP1, AP2, and AP3 in the AP MLD are EHT APs, while the non-AP STAs in the non-AP MLD can be EHT STAs or pre-EHT STAs.

[0123] Reference Figure 8C The R-TWT protocol has been established on three links (i.e., link 1, link 2, and link 3) between the AP MLD and the non-AP MLD. When no LL TID is mapped to all of links 1, 2, and 3 due to a TID-to-link mapping update / change, each AP in the AP MLD sends a TID-to-link mapping element with a terminating R-TWT mode indication on the corresponding link to announce the updated TID mapped to the corresponding link. The TID-to-link mapping element can be included in the MGMT frame transmitted from the AP to the STA on the corresponding link.

[0124] Once each STA in a non-AP MLD receives a TID-to-link mapping element on its corresponding link, the R-TWT SP will be ignored during the valid time interval of the updated TID-to-link mapping indicated in the TID-to-link mapping element. Furthermore, if the duration of the updated TID-to-link mapping indicated in the TID-to-link mapping element on the link exceeds a predetermined threshold, the R-TWT protocol on that link can be terminated.

[0125] Figure 9 This is a block diagram illustrating the format of a TID-to-link mapping element having an R-TWT information field with TID x according to some embodiments of the present invention. Figure 9 The format shown can be used in Figure 8B and Figure 8C In the embodiments described above. See also Figure 9 The TID-to-link mapping element is configured to include an R-TWT information field for TID x. This R-TWT information field indicates whether any LL TID is mapped to a link established between an AP MLD and a non-AP MLD, and whether R-TWT is permitted on these links. Two bits are allocated to each link to indicate the status of R-TWT operations on that link. For example, the two bits allocated to a link can be set to "11" to indicate that R-TWT operations are terminated on that link, or set to "10" to indicate that R-TWT operations are paused on that link, or set to "00" to indicate that an R-TWT protocol has not yet been established on that link.

[0126] In such Figures 8A to 8C In the embodiments shown above, the R-TWT element, the R-TWT SP silence element, the TID-to-link mapping element with a paused R-TWT mode indication, and the TID-to-link mapping element with a terminated R-TWT mode indication can be broadcast elements on a link established between an AP MLD and a non-AP MLD. However, in other embodiments, these elements may not be broadcast elements.

[0127] Various embodiments of the present invention also provide an AP for R-TWT operation of latency-sensitive traffic in a WLAN. Figure 10 This is a schematic diagram illustrating an AP 1000 according to some embodiments of the present invention. (Refer to...) Figure 10 AP 1000 may include a TID-to-link mapping unit 1010 and an R-TWT establishment unit 1020. The TID-to-link mapping unit 1010 may be configured to send a first response to a first STA in a non-AP MLD to map at least one TID of delay-sensitive traffic to at least one link established between the AP MLD and the non-AP MLD, wherein the AP MLD includes multiple APs, and the non-AP MLD includes multiple non-AP STAs, including the first STA. The R-TWT establishment unit 1020 may be configured to send an R-TWT response to the first STA to establish an R-TWT protocol on any one or more of the at least one link to which at least one TID of delay-sensitive traffic has been mapped.

[0128] In some embodiments, the TID-to-link mapping unit can also be configured to receive a first request from the first STA. That is, the first response from the first AP can be an unsolicited response or a requested response.

[0129] In some embodiments, the TID to link mapping unit 1010 may include: a first receiving unit configured to receive a first multi-link association request from a first STA; and a first transmitting unit 1 configured to send a first multi-link association response to the first STA to establish multiple links between an AP in an AP MLD and a STA in a non-AP MLD, and by default map all TIDs to all of the multiple links established between the AP MLD and the non-AP MLD, wherein all TIDs include at least one TID of latency-sensitive traffic.

[0130] Alternatively, in some embodiments, the TID to link mapping unit 1010 may include: a second receiving unit configured to receive a second multi-link association request from a first STA; and a second transmitting unit configured to send a second multi-link association response to the first STA to establish multiple links between an AP in an AP MLD and a STA in a non-AP MLD, and to map at least one TID of latency-sensitive traffic to a subset of the links established between the AP MLD and the non-AP MLD through a negotiation process with the first STA.

[0131] In some embodiments, the TID to link mapping unit 1010 may also be configured to receive a TID to link mapping request from a first STA in a non-AP MLD and send a TID to link mapping response to the first STA to map at least one TID of latency-sensitive traffic to a link between the AP MLD and a non-AP MLD to which the at least one TID of latency-sensitive traffic has not yet been mapped.

[0132] In some embodiments, the R-TWT establishment unit can also be configured to receive an R-TWT request from the first STA before sending an R-TWT response to the first STA. That is, the R-TWT protocol can be established by either an unsolicited R-TWT response from the first AP or a requested R-TWT response from the first AP.

[0133] In some embodiments, an R-TWT request and / or R-TWT response may include an R-TWT element, which includes a first subfield and a second subfield in a control field, wherein the first subfield is configured to indicate whether the information included in the R-TWT element is used for negotiating the parameters of the R-TWT, and the second subfield is configured to indicate whether the information included in the R-TWT element is applied to all links to which at least one TID of the latency-sensitive traffic has been mapped.

[0134] In some embodiments, the R-TWT establishment unit 1020 may also be configured to receive an integrated R-TWT request from a first STA and send an integrated R-TWT response to the first STA to map at least one TID of latency-sensitive traffic to at least one link between an AP MLD and a non-AP MLD to which the at least one TID of latency-sensitive traffic has not yet been mapped, and to establish an R-TWT protocol on any one or more of the at least one links to which the at least one TID of latency-sensitive traffic has been mapped.

[0135] In some embodiments, an integrated R-TWT request and / or integrated R-TWT response may be configured to include at least one first R-TWT element and at least one TID-to-link mapping element, the at least one first R-TWT element indicating at least one link on which an R-TWT protocol is established, and the at least one TID-to-link mapping element indicating at least one link on which at least one TID of latency-sensitive traffic is mapped. Alternatively, in some embodiments, an integrated R-TWT request and / or integrated R-TWT response may be configured to include at least one second R-TWT element, the at least one second R-TWT element indicating one or more links on which an R-TWT protocol is established, and at least one link on which at least one TID of latency-sensitive traffic is mapped. Figures 7A to 7CThe document shows three examples of the format of the broadcast TWT parameter set field in the R-TWT element.

[0136] In some embodiments, the AP 1000 may further include a first R-TWT termination unit configured to: tear up the R-TWT protocol established on the first link if a TID of no latency-sensitive traffic is mapped to a first link between the AP and the first STA due to a TID-to-link mapping update.

[0137] In some embodiments, AP 1000 may further include a second R-TWT termination unit, configured to: if the AP MLD and non-AP MLD support a suspended R-TWT operation mode, and no time-sensitive traffic TIDs are mapped to the first link established between the AP and the first STA, send an R-TWT SP silence element or a TID to a link mapping element indicating a suspended R-TWT mode on the first link to put the first link into a suspended R-TWT operation mode, or send a TID to a link mapping element indicating an R-TWT termination mode on the first link to terminate the R-TWT protocol on the first link. In some embodiments, the second R-TWT termination unit 1030B may further be configured to tear up the R-TWT protocol on the first link if the duration of the suspended R-TWT operation mode exceeds a predetermined threshold.

[0138] In some embodiments, the TID to link mapping element may include an R-TWT information field for the TID, which is set to indicate whether at least one TID of delay-sensitive traffic is mapped to multiple links established between an AP MLD and a non-AP MLD, and the state of the R-TWT operation, wherein the state of the R-TWT operation is set to indicate a suspended R-TWT operation mode, an R-TWT termination mode, or a non-existent R-TWT mode.

[0139] Various embodiments of the present invention also provide a STA for R-TWT operation of latency-sensitive traffic in a WLAN. Figure 11 This is a schematic diagram illustrating STA 1100 according to some embodiments of the present invention. (Refer to...) Figure 11STA 1100 may include a TID-to-link mapping request unit 1110 and an R-TWT request unit 1120. The TID-to-link mapping request unit 1110 may be configured to receive a first response from a first AP in an AP MLD to map at least one TID of delay-sensitive traffic to at least one link established between the AP MLD and a non-AP MLD, wherein the AP MLD includes a plurality of APs, including the first AP, and the non-AP MLD includes a plurality of non-AP STAs, including the STA. The R-TWT request unit 1120 may be configured to receive an R-TWT response from the first AP to establish an R-TWT protocol on any one or more of the at least one link to which at least one TID of delay-sensitive traffic has been mapped.

[0140] In some embodiments, the TID to link mapping request unit 1110 can also be configured to send a first request to the first AP. That is, the first response from the first AP can be an unrequested response or a requested response.

[0141] In some embodiments, the TID to link mapping request unit 1110 may include: a first transmission unit configured to send a first multi-link association request to a first AP; and a first receiving unit configured to receive a first multi-link association response from the first AP to establish multiple links between APs in the AP MLD and STAs in non-AP MLDs, and by default map all TIDs to all of the multiple links established between the AP MLD and non-AP MLDs, wherein all TIDs include at least one TID for latency-sensitive traffic.

[0142] Alternatively, in some embodiments, the TID to link mapping request unit 1110 may include: a second transmission unit configured to send a second multi-link association request to a first AP; and a second receiving unit configured to receive a second multi-link association response from the first AP to establish multiple links between APs in the AP MLD and STAs in non-AP MLDs, and to map at least one TID of delay-sensitive traffic to a subset of the links established between the AP MLD and non-AP MLDs through a negotiation process with the first AP.

[0143] In some embodiments, the TID to link mapping request unit 1110 may also be configured to send a TID to link mapping request to the first AP and receive a TID to link mapping response from the first AP, so as to map at least one TID of latency-sensitive traffic to a link between the AP MLD and a non-AP MLD to which the at least one TID of latency-sensitive traffic has not yet been mapped.

[0144] In some embodiments, the R-TWT request unit can also be configured to send an R-TWT request to the first AP before receiving an R-TWT response. That is, the R-TWT protocol can be established by either an unsolicited R-TWT response from the first AP or a requested R-TWT response from the first AP.

[0145] In some embodiments, an R-TWT request and / or R-TWT response may include an R-TWT element, which includes a first subfield and a second subfield in a control field, wherein the first subfield is configured to indicate whether the information included in the R-TWT element is used for negotiating the parameters of the R-TWT, and the second subfield is configured to indicate whether the information included in the R-TWT element is applied to all links to which at least one TID of the latency-sensitive traffic has been mapped.

[0146] In some embodiments, the R-TWT request unit 1120 may also be configured to send an integrated R-TWT request to the first AP and receive an integrated R-TWT response from the first AP to map at least one TID of latency-sensitive traffic to at least one link between the AP MLD and a non-AP MLD to which at least one TID of latency-sensitive traffic has not yet been mapped, and to establish an R-TWT protocol on any one or more of the at least one link to which at least one TID of latency-sensitive traffic has been mapped.

[0147] In some embodiments, an integrated R-TWT request and / or integrated R-TWT response may be configured to include at least one first R-TWT element and at least one TID-to-link mapping element, wherein the at least one first R-TWT element indicates at least one link on which an R-TWT protocol is established, and the at least one TID-to-link mapping element indicates at least one link on which at least one TID of delay-sensitive traffic is mapped.

[0148] Alternatively, in some embodiments, the integrated R-TWT request and / or integrated R-TWT response may be configured to include at least one second R-TWT element, which indicates one or more links on which the R-TWT protocol is established and at least one link to which at least one TID of latency-sensitive traffic is mapped. Figures 7A to 7C The document shows three examples of the format of the broadcast TWT parameter set field in the R-TWT element.

[0149] In some embodiments, STA 1100 may further include a first R-TWT termination unit configured to terminate the R-TWT protocol established on the first link if no time-sensitive traffic TID is mapped to the first link between the first AP and the STA.

[0150] In some embodiments, the STA 1100 may further include a second R-TWT termination unit, configured to: if the AP MLD and non-AP MLD support a suspended R-TWT operation mode, and no time-sensitive traffic TIDs are mapped to the first link established between the first AP and the STA, then upon receiving an R-TWT SP silence element or a TID-to-link mapping element indicating a suspended R-TWT mode sent by the first AP on the first link, cause the first link to enter a suspended R-TWT operation mode; or upon receiving a TID-to-link mapping element indicating an R-TWT termination sent by the first AP on the first link, terminate the R-TWT protocol on the first link. Preferably, the second R-TWT termination unit may also be configured to tear up the R-TWT protocol on the first link if the duration of the suspended R-TWT operation mode exceeds a predetermined threshold.

[0151] In some embodiments, the TID to link mapping element includes an R-TWT information field for the TID, which is set to indicate whether at least one TID of delay-sensitive traffic is mapped to multiple links established between an AP MLD and a non-AP MLD, and the state of the R-TWT operation, wherein the state of the R-TWT operation is set to indicate a suspended R-TWT operation mode, an R-TWT termination mode, or a non-existent R-TWT mode.

[0152] Various embodiments of the present invention also provide an access point (AP) for R-TWT operation for latency-sensitive traffic in a WLAN. The AP may include: a memory for storing instructions for performing a first method for R-TWT operation for latency-sensitive traffic in a WLAN; and a processor communicatively coupled to the memory, the processor being configured to execute the instructions to perform the first method for R-TWT operation for latency-sensitive traffic in a WLAN as described in various embodiments of the present invention.

[0153] Various embodiments of the present invention also provide a STA for R-TWT operation for latency-sensitive traffic in a WLAN. The STA may include: a memory for storing instructions for performing a second method for R-TWT operation for latency-sensitive traffic in a WLAN; and a processor communicatively coupled to the memory, the processor being configured to execute the instructions to perform the second method for R-TWT operation for latency-sensitive traffic in a WLAN as described in various embodiments of the present invention.

[0154] Various embodiments of the present invention also provide a computer program product including instructions that, when executed on a computer, cause the computer to perform any method according to any embodiment of the present invention for R-TWT operation for latency-sensitive traffic in a WLAN.

[0155] Various embodiments of the present invention also provide a computer program including instructions that, when executed on a computer, cause the computer to perform a method for R-TWT operation for latency-sensitive traffic in a WLAN according to any embodiment of the present invention.

[0156] Various embodiments of the present invention also provide a non-volatile storage medium including computer program code that, when executed on a computer, causes the computer to perform a method for R-TWT operation for latency-sensitive traffic in a WLAN according to any embodiment of the present invention.

[0157] Various embodiments of the present invention also provide a chip configured to perform a method for R-TWT operation for latency-sensitive traffic in a WLAN according to any embodiment of the present invention.

[0158] At least some steps of the method for R-TWT operation for latency-sensitive traffic in a WLAN according to any embodiment of the present invention can be implemented using hardware, a processor executing firmware instructions, a processor executing software instructions, or any combination thereof. When implemented using a processor executing software or firmware instructions, the software or firmware instructions can be stored in any computer-readable storage medium, such as a disk, optical disk, or other storage medium, stored in RAM or ROM or flash memory, a processor, a hard disk drive, an optical disk drive, a tape drive, etc. Similarly, the software or firmware instructions can be transmitted to the user or system via any known or desired transmission method, including, for example, on a computer-readable disk or other portable computer storage mechanism, or via a communication medium. As described above, the various embodiments of the present invention provide an efficient mechanism for R-TWT operations on latency-sensitive traffic in WLANs to further optimize spectral efficiency, increase throughput, and reduce WLAN power consumption. The methods and apparatus provided in the embodiments of the present invention can, depending on the actual needs of the communication system, perform the TID-to-link mapping as a default process during or after the multi-link establishment process, a negotiation process together with the multi-link establishment process, a separate negotiation process after the multi-link establishment process, or a negotiation process integrated with the R-TWT establishment process.

[0159] It should be understood that the embodiments and features described above should be considered exemplary rather than limiting. Many other embodiments will be apparent to those skilled in the art upon consideration of the specification and practice of the invention. Therefore, the scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents. Furthermore, certain terminology is used for the purpose of clarity of description and is not intended to limit the embodiments disclosed in the invention.

Claims

1. A method for constrained target wake-up time (R-TWT) operation of delay-sensitive traffic in a wireless local area network (WLAN), the method comprising: The first AP in the AP MLD sends an R-TWT response to the first STA in the non-AP MLD to establish the R-TWT protocol on one or more links in at least one link to which at least one traffic identifier (TID) of delay-sensitive traffic has been mapped. The mapping from the at least one TID of the latency-sensitive traffic to the at least one link is established in the following manner: The first AP sends a first response to the first STA to map at least one TID of latency-sensitive traffic to at least one link established between an AP MLD and a non-AP MLD, wherein the AP MLD includes multiple APs and the non-AP MLD includes multiple non-AP STAs.

2. The method according to claim 1, further comprising: The first AP receives a first request from the first STA.

3. The method according to claim 2, wherein, The receipt of the first request from the first STA includes: The first AP receives a first multi-link association request from the first STA, and Sending the first response includes: The first AP sends a first multi-link association response to the first STA to establish multiple links between the AP in the AP MLD and the STA in the non-AP MLD, and by default maps all TIDs to all links in the multiple links established between the AP MLD and the non-AP MLD, wherein all TIDs include at least one TID of latency-sensitive traffic.

4. The method according to claim 2, wherein, The receipt of the first request from the first STA includes: The first AP receives a second multi-link association request from the first STA, and Sending the first response includes: The first AP sends a second multi-link association response to the first STA to establish multiple links between the AP in the AP MLD and the STA in the non-AP MLD, and maps at least one TID of delay-sensitive traffic to a subset of the links established between the AP MLD and the non-AP MLD through a negotiation process with the first STA.

5. The method according to claim 4, further comprising: The first AP receives a TID-to-link mapping request from the first STA; as well as The first AP sends a TID to the first STA in a link mapping response to map at least one TID of latency-sensitive traffic to a link between the AP MLD and the non-AP MLD to which at least one TID of latency-sensitive traffic has not yet been mapped.

6. The method according to any one of claims 1 to 5, further comprising: Before sending the R-TWT response to the first STA, the first AP receives the R-TWT request from the first STA.

7. The method of claim 6, comprising: The R-TWT request and / or the R-TWT response includes one or more R-TWT elements, the R-TWT elements including a broadcast R-TWT parameter set field, the broadcast R-TWT parameter set field including an R-TWT traffic information field.

8. The method according to claim 7, wherein, The R-TWT traffic information field includes: a traffic information control subfield, an R-TWT downlink TID bitmap subfield, and an R-TWT uplink TID bitmap subfield; Among them, the R-TWT downlink TID bitmap subfield is set to indicate the time-sensitive traffic flow in the downlink direction on the link indicated in the link ID bitmap subfield, where the TID is identified by the TWT-scheduled AP or the TWT-scheduled STA. The R-TWT uplink TID bitmap subfield is set to indicate the delay-sensitive traffic flow in the uplink direction on the link indicated in the link ID bitmap subfield, where the TID is identified by the TWT-scheduled AP or the TWT-scheduled STA.

9. The method according to claim 8, wherein, The value of 1 or 0 at bit position k in the bitmap of the R-TWT downlink TID bitmap subfield and the R-TWT uplink TID bitmap subfield is set to indicate that TID k is classified as a delay-sensitive traffic flow.

10. The method according to claim 9, wherein, The value of 1 or 0 at bit position k in the bitmap of the R-TWT downlink TID bitmap subfield and the R-TWT uplink TID bitmap subfield indicates that the MSDU of TID k is allowed / not allowed to be transmitted on the link indicated in the link ID bitmap subfield in one or more R-TWT SPs indicated by the TWT element.

11. The method according to any one of claims 1 to 10, wherein, If a TID of a traffic without latency-sensitive traffic is mapped to the first link established between the first AP and the first STA due to a TID-to-link mapping update, then the R-TWT protocol established on the first link is terminated by the first AP.

12. An access point (AP) for R-TWT operation of delay-sensitive traffic in a WLAN, the AP comprising: Memory, used to store instructions; And a processor, communicatively coupled to the memory, the processor being configured to execute instructions stored in the memory to perform the method of any one of claims 1-11.

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