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US-20260129528-A1 - SIGNALING TO TRANSFER TARGET WAKE TIME AGREEMENTS BETWEEN LINKS WITHIN OR ACROSS MULTI-LINK DEVICES

US20260129528A1US 20260129528 A1US20260129528 A1US 20260129528A1US-20260129528-A1

Abstract

Embodiments for enabling a non-access point (non-AP) multi-link device (MLD) to transfer one or more existing Target Wake Time (TWT) agreements to a new link either for an AP MLD or across AP MLDs. In at least one embodiment, a computer-implemented method is provided that includes obtaining, from a non-AP MLD that is seeking to roam from a first AP MLD to a second AP MLD, a request to transfer one or more TWT agreements from one or more wireless links of the first AP MLD to one or more wireless links of the second AP MLD; determining whether any of the one or more TWT agreements are accepted for any wireless links of the second AP MLD; and providing a response to the non-AP MLD indicating whether any of the TWT agreements are accepted for the wireless links of the second AP MLD.

Inventors

  • Binita Gupta
  • Brian D. Hart
  • Malcolm M. Smith
  • Indermeet Singh Gandhi

Assignees

  • CISCO TECHNOLOGY, INC.

Dates

Publication Date
20260507
Application Date
20250425

Claims (20)

  1. 1 . A method comprising: obtaining, from a non-access point multi-link device (non-AP MLD) that is seeking to roam from a first access point multi-link device (AP MLD) to a second AP MLD, a request to transfer one or more Target Wake Time (TWT) agreements for the non-AP MLD from one or more wireless links of the first AP MLD to one or more wireless links of the second AP MLD; determining whether any of the one or more TWT agreements are accepted for the one or more wireless links of the second AP MLD; and providing a response to the non-AP MLD indicating whether any of the one or more TWT agreements are accepted for the one or more wireless links of the second AP MLD.
  2. 2 . The method of claim 1 , wherein the request is a roaming request frame, a link reconfiguration request frame, a Fast Transition (FT) request frame, or a management frame.
  3. 3 . The method of claim 2 , wherein the request corresponds to at least one of an add link operation, a switch link operation, or a delete link operation.
  4. 4 . The method of claim 1 , wherein the request indicates the one or more TWT agreements that are requested to be transferred to the one or more wireless links of the second AP MLD using one of: one or two TWT elements for each TWT agreement of the one or more TWT agreements; a TWT agreement type and a TWT identifier for each TWT agreement of the one or more TWT agreements; or a TWT agreement type identifier for each type of the one or more TWT agreements.
  5. 5 . The method of claim 4 , wherein the request further indicates wireless link identifier (ID) information indicating at least one wireless link of the first AP MLD at which the one or more TWT agreements that are requested to be transferred are set up.
  6. 6 . The method of claim 5 , wherein the wireless link ID information, the TWT agreement type and the TWT identifier for each TWT agreement of the one or more TWT agreements or the wireless link ID information and the TWT agreement type identifier for each type of the one or more TWT agreements are indicated in a TWT transfer information field of a station information (STA Info) field of a per-station profile (Per-STA Profile) subelement of the request.
  7. 7 . The method of claim 6 , wherein the TWT transfer information field of the STA Info field of the Per-STA Profile subelement includes one or more of: a first field that is set to indicate that all individual TWT agreements for the non-AP MLD that are set up on a particular wireless link of the first AP MLD are requested to be transferred; a second field that is set to indicate that all broadcast TWT agreements for the non-AP MLD that are set up on a particular wireless link of the first AP MLD are requested to be transferred; or a third field that is set to indicate that all restricted TWT agreements for the non-AP MLD that are set up on a particular wireless link of the first AP MLD are requested to be transferred.
  8. 8 . The method of claim 1 , wherein the request further indicates a plurality of TWT agreements from multiple wireless links of the first AP MLD to be transferred to a particular wireless link of the second AP MLD.
  9. 9 . The method of claim 1 , wherein the response is a roaming response frame, a link reconfiguration response frame, a Fast Transition (FT) response frame, or a management frame.
  10. 10 . The method of claim 1 wherein, for a particular TWT agreement that is accepted for a particular wireless link of the second AP MLD, the response includes a TWT element for the particular TWT agreement that is accepted.
  11. 11 . The method of claim 10 , wherein the TWT element is provided in a per-station profile (Per-STA Profile) subelement of the response.
  12. 12 . The method of claim 10 , wherein, for the particular TWT agreement that is accepted for the wireless link of the second AP MLD, at least a target wake time field of the TWT element is updated to adjust for a time synchronization function (TSF) offset of the particular wireless link of the second AP MLD for which the particular TWT agreement is accepted.
  13. 13 . The method of claim 1 , wherein the response further indicates one or more of: at least one counter proposal TWT agreement for at least one TWT agreement that is not accepted for the one or more wireless links; or at least one new TWT agreement that is capable of being accepted for the one or more wireless links by the second AP MLD.
  14. 14 . The method of claim 1 , wherein the request is a first request that is obtained by the first AP MLD from the non-AP MLD and the response is a first response that is provided to the non-AP MLD, the method further comprising: transmitting, by the first AP MLD, a second request to the second AP MLD via a distribution system (DS) communication that includes one or more TWT elements for the one or more TWT agreements to be transferred to the one or more wireless links of the second AP MLD based on the first request, wherein the second AP MLD determines whether any of the one or more TWT agreements are accepted for the one or more wireless links of the second AP MLD; and obtaining a second response, by the first AP MLD from the second AP MLD via another DS communication that indicates status for the one or more TWT agreements that were requested to be transferred in the second request, wherein providing the first response to the non-AP MLD includes the first AP MLD transmitting the first response to the non-AP MLD based on the second response.
  15. 15 . The method of claim 1 , wherein the request is obtained by the second AP MLD from the non-AP MLD and the response is provided by the second AP MLD.
  16. 16 . The method of claim 15 , wherein upon the request indicating wireless link identifying information for the one or more wireless links of the first AP MLD and a TWT agreement type and TWT identifier for each TWT agreement of the one or more TWT agreements or the request indicating wireless link identifying information for the one or more wireless links of the first AP MLD and a TWT agreement type identifier for each type of the one or more TWT agreements, the method further comprising: fetching the one or more TWT agreements from the first AP MLD by the second AP MLD as part of roaming context transfer communications between the first AP MLD and the second AP MLD.
  17. 17 . The method of claim 1 , wherein the request further includes one or more TWT elements for one or more new TWT agreements requested to be set up for at least one wireless link of the second AP MLD.
  18. 18 . The method of claim 17 , wherein a corresponding TWT element for each of the one or more new TWT agreements is included in a per-station profile (Per-STA Profile) subelement for the at least one wireless link of the second AP MLD where the one or more new TWT agreements are requested to be set up.
  19. 19 . The method of claim 17 , wherein the response further indicates whether any of the one or more new TWT agreements are accepted for the at least one wireless link of the second AP MLD.
  20. 20 . The method of claim 19 , wherein for a particular new TWT agreement that is accepted for a particular wireless link of the second AP MLD, at least a target wake time field of a particular TWT element is updated to adjust for a time synchronization function (TSF) offset of the particular wireless link of the second AP MLD for which the particular new TWT agreement is accepted.

Description

PRIORITY CLAIM This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 63/715,521, filed Nov. 2, 2024, the entirety of which is incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to wireless networking. BACKGROUND Networking architectures have grown increasingly complex in communications environments, particularly wireless networking environments. For wireless local area networks, Institute of Electrical and Electronics Engineers (IEEE) 802.11be (Wi-Fi® 7) defines various features to facilitate Multi-Link Operation (MLO) for Multi-Link Devices (MLDs) that are capable of associating and simultaneously exchange data traffic on multiple Radio Frequency (RF) bands or ‘links’. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a system that may be implemented to facilitate techniques for transferring Target Wake Time (TWT) agreements between links with a current access point (AP) Multi-Link Device (MLD) or between AP MLDs within a Seamless Mobility Domain (SMD), according to an example embodiment. FIG. 2 is a call flow diagram depicting techniques for transferring TWT agreements as part of link reconfiguration signaling, according to an example embodiment. FIG. 3 is a call flow diagram depicting techniques for TWT agreement setup with a current AP MLD as part of link reconfiguration signaling, according to an example embodiment. FIGS. 4A, 4B, and 4C are diagrams showing example formats for signaling one or more TWT elements, TWT agreement identifiers, or TWT agreement types to facilitate transferring one or more TWT agreements, according to various example embodiments. FIGS. 4D-1 and 4D-2 are diagrams showing example formats for signaling one or more TWT agreement identifiers or TWT agreement types to facilitate transferring one or more TWT agreements, according to various example embodiments. FIG. 5 is a flowchart depicting a method according to an example embodiment. FIGS. 6 and 7 are call flow diagrams depicting techniques for TWT agreement transfer when a non-AP MLD roams from one AP MLD to another AP MLD within a Seamless Mobility Domain (SMD), according to an example embodiment. FIG. 8 is a flowchart depicting another method according to an example embodiment. FIG. 9 is a flowchart depicting another method according to an example embodiment. FIG. 10 is a hardware block diagram of device configured to perform functions associated with operations discussed in connection with embodiments herein. DETAILED DESCRIPTION Overview Innovations in wireless access points (APs) and devices for wireless local area network (WLAN) technologies, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (e.g., Wi-Fi®) technologies, have led to the development of Multi-Link Devices (MLDs) that are capable of Multi-Link Operation (MLO), as prescribed by IEEE 802.11be (and marketed as Wi-Fi® 7)). For MLO, MLDs can associate and simultaneously exchange data traffic on multiple Radio Frequency (RF) bands, such as 2.4 Gigahertz (GHz), 5 GHz, and/or 6 GHz bands. MLDs can include AP MLDs and non-AP MLDs. Non-AP MLDs are often referred to as MLD client devices, MLD-STAs (STA=abbreviation of station), or STA MLDs; the term “client” can also refer to a STA MLD. An AP MLD can be configured with multiple RF transceivers and baseband processors/Media Access Control (MAC) processors to facilitate MLO. Similarly, a non-AP MLD can be configured with multiple RF transceivers and baseband processors/Media Access Control (MAC) processors to facilitate MLO. As referred to herein, the terms ‘link’, ‘wireless link’, and variations thereof can refer to a wireless connection through which a station (of a non-AP MLD) can wirelessly connect to/access the wireless connection provided by an AP (of an AP MLD). Each link can use a different channel of a certain bandwidth. A mechanism is presented herein to enable a non-AP MLD to be able to transfer one or more of its existing Target Wake Time (TWT) agreements to a new link when it switches an existing link to the new link, either within an MLD or across MLDs, or deletes a link to avoid any disruption to ongoing services/flows associated with those TWT schedules. In at least one embodiment, a method is provided that may include: obtaining, from a non-access point multi-link device (non-AP MLD) that is seeking to roam from a first access point multi-link device (AP MLD) to a second AP MLD, a request to transfer one or more Target Wake Time (TWT) agreements for the non-AP MLD from one or more wireless links of the first AP MLD to one or more wireless links of the second AP MLD; determining whether any of the one or more TWT agreements are accepted for the one or more wireless links of the second AP MLD; and providing a response to the non-AP MLD indicating whether any of the one or more TWT agreements are accepted for the one or more wireless links of the second AP MLD. In at least one embodiment, a met