Wireless local area network connection-before-disconnection handover

Abstract

Certain aspects of the present disclosure provide a method for wireless communication at a wireless node, generally including: communicating with a first access point (AP) device affiliated to a single mobile domain (SMD) entity via a first link; outputting a first message for transmission to the first AP device, the first message comprising a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to a second AP device affiliated to the SMD entity; communicating with the second AP device via a second link during the handover after obtaining a second indication that the context information has been transmitted from the first AP device to the second AP device; and disabling the first link with the first AP device after obtaining a third indication to trigger the wireless node to disable the first link with the first AP device.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application No. 18 / 340,001, filed on June 22, 2023, which is a continuation-in-part of U.S. patent application No. 17 / 954,321, filed on September 27, 2022, both of which are hereby assigned to the assignee of this application and are hereby expressly incorporated by reference in their entirety into this application, as if fully set forth below, and for all applicable purposes. Technical Field

[0003] Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for wireless local area network (WLAN) make-before-break handover. Background Art

[0004] Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, and single carrier FDMA (SC-FDMA) networks.

[0005] To address the problem of increasing bandwidth requirements required for wireless communication systems, different schemes are being developed to allow multiple user terminals to communicate with a single access point by sharing channel resources while achieving high data throughput. Multiple-input multiple-output (MIMO) technology represents one such approach that has emerged as a popular technology for communication systems. MIMO technology has been adopted in several wireless communication standards such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards. The IEEE 802.11 standards represent a collection of wireless local area network (WLAN) air interface standards developed by the IEEE 802.11 committee for short-range communications (such as tens of meters to hundreds of meters).

[0006] In wireless systems (such as networks compliant with IEEE 802.11), wireless stations (STAs) often roam between the coverage areas of different access points (APs). In traditional systems, when a STA roams, the STA switches from a source AP (currently serving the STA) to a target AP. As part of this switching process, the STA usually needs to reassociate with the target AP. Reassociation is usually required before the network can switch the data path from the source AP to the target AP. Unfortunately, the reassociation process can be relatively time-consuming and interrupt the data flow, which can have an adverse effect on the user experience. Summary of the invention

[0007] On the one hand, a method for wireless communication at a wireless node is provided. The method includes: communicating with a first access point (AP) device attached to a single mobility domain (SMD) entity via a first link; outputting a first message for transmission to the first AP device, the first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to a second AP device attached to the SMD entity; after obtaining a second indication that context information has been transmitted from the first AP device to the second AP device, communicating with the second AP device via a second link during the handover; and after obtaining a third indication that triggers the wireless node to disable the first link with the first AP device, disabling the first link with the first AP device.

[0008] On the other hand, a method for wireless communication at a first access point (AP) device is provided. The method includes: communicating with a wireless node attached to a single mobility domain (SMD) entity via a first link, the first AP device and the second AP device also both attached to the SMD entity; obtaining a first message from the wireless node, the first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to the second AP device; after obtaining the first message, outputting context information for transmission to the second AP device; outputting a second indication for triggering the wireless node to enable a second link with the second AP device for transmission to the wireless node; and outputting a third indication for triggering the wireless node to disable the first link with the first AP device for transmission to the wireless node.

[0009] Another aspect provides a method for wireless communication at a wireless node. The method includes: communicating with a first access point (AP) device attached to a single mobility domain (SMD) entity via a first link; obtaining a first message from the first AP device, the first message including a first indication that the wireless node will switch from the first AP device to a second AP device also attached to the SMD entity; after obtaining or outputting a second indication for transmission, communicating with the second AP device via a second link during the switching; and disabling the first link with the first AP device after obtaining a third indication.

[0010] On the other hand, a method for wireless communication at a first access point (AP) device is provided. The method includes: communicating with a wireless node attached to a single mobility domain (SMD) entity via a first link, the first AP device and the second AP device also both attached to the SMD entity; outputting a first message for transmission to the wireless node, the first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to the second AP device; after sending the first message, outputting context information for transmission to the second AP device; and outputting a second indication for enabling a second link with the second AP device for transmission to the wireless node.

[0011] Other aspects provide: an apparatus operable, configured, or otherwise adapted to perform any one or more of the methods described above and / or elsewhere herein; a non-transitory computer-readable medium comprising instructions that, when executed by a processor of the apparatus, cause the apparatus to perform the methods described above and elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising code for performing the methods described above and elsewhere herein; and / or an apparatus comprising an apparatus for performing the methods described above and elsewhere herein. For example, an apparatus may include a processing system, a device having a processing system, or a processing system cooperating through one or more networks.

[0012] The following description and drawings set forth certain features for purposes of illustration. Details of one or more implementations of the subject matter described in the present disclosure are set forth in the drawings and the following description. Other features, aspects, and advantages will become apparent from the specification, drawings, and claims. Please note that the relative dimensions of the following figures may not be drawn to scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings depict certain features of the various aspects described herein and should not be considered as limiting the scope of the disclosure.

[0014] Figure 1 An exemplary wireless communication network is depicted.

[0015] Figure 2 An exemplary disaggregated base station architecture is depicted.

[0016] Figure 3 A block diagram of an exemplary multi-link device (MLD) deployment is depicted.

[0017] Figure 4 An exemplary multi-link operation (MLO) architecture is depicted.

[0018] 5A , 5B and 5C depict example make-before-break switching implemented in an MLO architecture.

[0019] 6A, 6B, and 6C depict example associated linksets and example enabled linksets before, during, and after make-before-break switching.

[0020] Figure 7 Depicted is an example transmission of a multi-link device (MLD) context including a switching buffer during make-before-break switching.

[0021] Figure 8 Depicted is an example call flow for a network initiated make-before-break handover.

[0022] Fig. 9 Depicted is an example call flow for a client-initiated make-before-break handover.

[0023] Fig.10 Depicted are example call flows for a station-initiated handover in accordance with certain aspects of the present disclosure.

[0024] Fig.11 Depicted are example call flows for station-initiated handover in a single radio scenario in accordance with certain aspects of the present disclosure.

[0025] Fig.12 An example call flow for station-initiated handover in a multi-radio scenario is illustrated, in accordance with certain aspects of the present disclosure.

[0026] Fig.13 Depicted are example call flows for a network initiated handover in accordance with certain aspects of the present disclosure.

[0027] Fig.14 Depicted are example call flows for network initiated handover in a single radio scenario in accordance with certain aspects of the present disclosure.

[0028] Fig.15 Depicted are example call flows for network initiated handover in a multi-radio scenario in accordance with certain aspects of the present disclosure.

[0029] Fig.16 A flow chart illustrating an example method for wireless communications is depicted.

[0030] Fig.17 A flow chart illustrating an example method for wireless communications is depicted.

[0031] Fig.18 A flow chart illustrating an example method for wireless communications is depicted.

[0032] Fig.19 A flow chart illustrating an example method for wireless communications is depicted.

[0033] Fig. 20A flow chart illustrating an example method for wireless communications is depicted.

[0034] Fig.21 A flow chart illustrating an example method for wireless communications is depicted.

[0035] Fig. 22 A flow chart illustrating an example method for wireless communications is depicted.

[0036] Fig.23 A block diagram of an example wireless communication device is depicted. DETAILED DESCRIPTION

[0037] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for make-before-break handover in a wireless local area network.

[0038] In a conventional wireless communication system, when a station (STA) roams between multiple access points (APs), the STA needs to reassociate with the new (target) AP and perform an association procedure (e.g., including a 4-way handshake procedure). The 4-way handshake procedure is a process in which four messages are exchanged between the AP and a non-AP MLD to generate and exchange various encryption keys used to encrypt data sent between the AP and the STA. This four-message exchange may cause undue delays when the STA roams between APs, but needs to be performed before the network can switch data paths. Therefore, this type of roaming or switching between APs is called a break-before-make handover because the connection to the serving AP is interrupted before connecting to the target AP, which results in data interruption and additional delays during the handover process.

[0039] To address this problem, the technology disclosed herein provides a technology that utilizes the features of a multi-link operation (MLO) architecture to address this problem. MLO generally refers to features in advanced wireless systems (e.g., features defined by the IEEE 802.11-2020 specification or its amendments, including but not limited to 802.11be Extremely High Throughput (EHT) and 802.11 amendments associated with Wi-Fi 8) that enable transmission and reception between devices using multiple links using a single frequency channel. MLO can enable an AP, a client, or both to simultaneously utilize multiple radio links of different frequency channels / bands. Devices capable of MLO are generally referred to as multi-link devices (MLDs).

[0040] According to certain aspects of the present disclosure, non-collocated APs (i.e., APs that exist in different physical locations) can be connected as subordinate APs of a single AP MLD. Therefore, when a (non-AP MLD) STA moves between these APs, the STA can bypass the MLO (re)association and 4-way handshake process. Therefore, the technology proposed in this article provides a connect-before-break handover process, which can avoid data interruption and reduce delays during handover.

[0041] Introduction to Wireless Communication Networks

[0042] The various aspects of the present disclosure will be described more fully below with reference to the accompanying drawings. However, the present disclosure can be implemented in many different forms and should not be interpreted as being limited to any specific structure or function throughout the present disclosure. On the contrary, these aspects are provided so that the present disclosure will be thorough and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. Based on the teachings of this article, it should be understood by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the disclosure disclosed herein, whether it is implemented independently of any other aspect of the present disclosure or implemented in combination with any other aspect of the present disclosure. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such devices or methods, and the device or method uses other structures, functions, or structures and functions on the various aspects of the present disclosure set forth herein or in addition to the various aspects of the present disclosure set forth herein to practice. It should be understood that any aspect of the present disclosure disclosed herein can be embodied by one or more elements of the claims.

[0043] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.

[0044] Although specific aspects are described herein, many variations and permutations of these aspects fall within the scope of the present disclosure. Although some benefits and advantages of preferred aspects are mentioned, the scope of the present disclosure is not intended to be limited to specific benefits, uses or purposes. On the contrary, various aspects of the present disclosure are intended to be broadly applicable to different wireless technologies, system configurations, networks and transmission protocols, some of which are shown by way of example in the accompanying drawings and in the following description of preferred aspects. The detailed description and drawings are merely illustrative of the present disclosure and are not limiting, and the scope of the present disclosure is defined by the appended claims and their equivalents.

[0045] The technology described herein can be used in various broadband wireless communication systems, including communication systems based on orthogonal multiplexing schemes. Examples of such communication systems include space division multiple access (SDMA), time division multiple access (TDMA), orthogonal frequency division multiple access systems (OFDMA), single carrier frequency division multiple access (SC-FDMA) systems, and the like. SDMA systems can use sufficiently different directions to simultaneously send data belonging to multiple user terminals. TDMA systems can allow multiple user terminals to share the same frequency channel by dividing the transmission signal into different time slots, each of which is assigned to a different user terminal. OFDMA systems use orthogonal frequency division multiplexing (OFDM), which is a modulation technique that divides the entire system bandwidth into multiple orthogonal subcarriers. These subcarriers may also be referred to as tones, bins, and the like. Using OFDM, each subcarrier can be modulated independently with data. SC-FDMA systems can use interleaved FDMA (IFDMA) to transmit on subcarriers distributed across the system bandwidth, localized FDMA (LFDMA) to transmit on adjacent subcarrier blocks, or enhanced FDMA (EFDMA) to transmit on multiple blocks of adjacent subcarriers. Typically, modulation symbols are sent in the frequency domain using OFDM and in the time domain using SC-FDMA.

[0046] The teachings herein may be incorporated into various wired or wireless devices (such as nodes) (such as implemented in or performed by various wired or wireless devices). In some aspects, a wireless node implemented according to the teachings herein may include an access point (AP), a wireless station (STA), a non-AP STA, a non-AP multi-link device (MLD), or an access terminal.

[0047] An access point ("AP") may include, be implemented as, or be known as a Node B, a radio network controller ("RNC"), an evolved Node B (eNB), a base station controller ("BSC"), a base transceiver station ("BTS"), a base station ("BS"), a transceiver function ("TF"), a radio router, a radio transceiver, a basic service set ("BSS"), an extended service set ("ESS"), a radio base station ("RBS"), or some other terminology.

[0048] An access terminal ("AT") may include, be implemented as or be known as a subscriber station, a subscriber unit, a mobile station (MS), a remote station, a remote terminal, a user terminal (UT), a user agent, a user device, a user equipment (UE), a user station or some other terms. In some embodiments, the access terminal may include a cellular phone, a cordless phone, a session initiation protocol ("SIP") phone, a wireless local loop ("WLL") station, a personal digital assistant ("PDA"), a handheld device with wireless connection capability, a station ("STA") or some other suitable processing devices connected to a wireless modem. Therefore, one or more aspects of the teachings herein may be incorporated into a phone (such as a cellular phone or a smart phone), a computer (such as a laptop), a tablet computer, a portable communication device, a portable computing device (such as a personal data assistant), an entertainment device (such as a music or video device or a satellite radio), a global positioning system (GPS) device, or any other suitable device configured to communicate via a wireless or wired medium. In some aspects, the node is a wireless node. For example, such a wireless node may provide connectivity for or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link.

[0049] Example Wireless Communication System

[0050] Figure 1 is a diagram illustrating an example wireless communication system 100 in accordance with certain aspects of the present disclosure. System 100 may be a multiple-input multiple-output (MIMO) / multiple-link operation (MLO) system 100. Figure 1 As shown, access point (AP) 110 includes association manager 112, which can be configured to take one or more actions described herein. Wireless station (STA) 120a includes association manager 122, which can be configured to take one or more actions described herein. In various aspects, AP 110 and wireless station 120a can be MLDs, as described herein with respect to Figure 3 Further described.

[0051] For simplicity, in Figure 1Only one AP 110 is shown in the figure. An AP is typically a fixed station that communicates with a wireless STA, and may also be referred to as a base station (BS) or some other term. A wireless STA may be fixed or mobile, and may also be referred to as a mobile STA, a wireless device, or some other term. AP 110 may communicate with one or more wireless STAs 120 on a downlink (DL) and / or uplink (UL) at any given moment. DL (i.e., forward link) is a communication link from AP 110 to wireless STA 120, and UL (i.e., reverse link) is a communication link from wireless STA 120 to AP 110. Wireless STA 120 may also communicate peer-to-peer with another wireless STA, for example, via a direct link such as tunneled direct link setup (TDLS). A system controller 130 may communicate with access points and provide coordination and control for the access points.

[0052] Although portions of the following disclosure will describe wireless STAs 120 that are capable of communicating via spatial division multiple access (SDMA), for certain aspects, the wireless STAs 120 may also include some wireless STAs 120 that do not support SDMA. Therefore, for these aspects, the AP 110 may be configured to communicate with both SDMA and non-SDMA wireless STAs 120. This approach may conveniently allow older versions of wireless STAs 120 ("legacy" stations) to remain deployed in an enterprise, extending their useful life, while allowing newer SDMA wireless STAs 120 to be introduced as deemed appropriate.

[0053] System 100 employs multiple transmit antennas and multiple receive antennas for data transmission on DL and UL. AP 110 is equipped with N ap The set of K selected wireless stations 120 collectively represents the multiple output of DL transmission and the multiple input of UL transmission. For pure SDMA, if the data symbol streams of the K wireless STAs are not multiplexed in code, frequency, or time in some way, it is desirable to have N ap ≥K≥1. K may be greater than N if the data symbol streams can be multiplexed using TDMA techniques, using different code channels of CDMA, using non-overlapping subband sets of OFDM, etc. ap Each selected wireless STA sends user-specific data to the access point and / or receives user-specific data from the access point. In general, each selected wireless STA may be equipped with one or more antennas (ie, N sta ≥1). The K selected wireless STAs may have the same or different numbers of antennas.

[0054] System 100 may be a time division duplex (TDD) system or a frequency division duplex (FDD) system. For a TDD system, DL and UL share the same frequency band. For an FDD system, DL and UL use different frequency bands. System 100 may also utilize a single carrier or multiple carriers for transmission. Each wireless STA may be equipped with a single antenna or multiple antennas. If wireless STA 120 shares the same frequency channel by dividing transmission / reception into different time slots, system 100 may also be a TDMA system, with each time slot being allocated to a different wireless STA.

[0055] Figure 2 1 shows a block diagram of an AP 110 and two wireless STAs 120m and 120x in a MIMO / MLO system such as system 100 according to certain aspects of the present disclosure. In certain aspects, the AP 110 and / or the wireless STAs 120m and 120x may perform various techniques to ensure that non-AP MLDs are able to receive group addressed frames. For example, the AP 110 and / or the wireless STAs 120m and 120x may include the following: Figure 1 The corresponding association manager described.

[0056] AP 110 is equipped with N ap The wireless STA 120m is equipped with N antennas 224a to 224t. sta,m antennas 252ma to 252mu, and the wireless STA 120x is equipped with N sta,x The AP 110 is a transmitting entity for DL ​​and a receiving entity for UL. Each wireless STA 120 is a transmitting entity for UL and a receiving entity for DL. As used herein, a "transmitting entity" is an independently operated device or equipment capable of transmitting data via a wireless channel, and a "receiving entity" is an independently operated device or equipment capable of receiving data via a wireless channel. The term communication generally refers to transmission, reception, or both. In the following description, the subscript "DL" indicates downlink, the subscript "UL" indicates uplink, and N UL Wireless STAs are selected for simultaneous transmission on the uplink, N DL Wireless STAs are selected for simultaneous transmission on the downlink, N UL May or may not be equal to N DL , and N UL and N DL It may be a static value, or may change for each scheduling interval.Beam steering or some other spatial processing technique may be used at the access point and wireless station.

[0057] On the UL, at each wireless STA 120 selected for UL transmission, a transmit (TX) data processor 288 receives traffic data from a data source 286 and control data from a controller 280. The TX data processor 288 processes (e.g., encodes, interleaves, and modulates) the traffic data of the wireless station based on a coding and modulation scheme associated with a rate selected for the wireless STA and provides a data symbol stream. The TX spatial processor 290 performs spatial processing on the data symbol stream and generates a TX signal for the N STA. sta,m The antennas provide N sta,m Each transceiver (TMTR) 254 receives and processes (eg, converts to analog, amplifies, filters, and upconverts) a corresponding transmit symbol stream to generate an uplink signal. sta,m The transceivers 254 provide N sta,m UL signals for N sta,m transmission from antenna 252 to AP 110.

[0058] N UL Wireless STAs may be scheduled for simultaneous transmission on the uplink. Each of these wireless STAs performs spatial processing on its data symbol stream and sends its set of transmit symbol streams to AP 110 on the UL.

[0059] At AP 110, N ap The antennas 224a to 224ap receive signals from all N signals transmitted on the UL. UL Each antenna 224 provides a received signal to a corresponding transceiver (RCVR) 222. Each transceiver 222 performs processing complementary to that performed by transceiver 254 and provides a received symbol stream. Receive (RX) spatial processor 240 processes the received signals from N ap N of transceivers 222 ap The receiver performs spatial processing on the received symbol streams and provides N UL Receiver spatial processing is performed based on channel correlation matrix inversion (CCMI), minimum mean square error (MMSE), soft interference cancellation (SIC), or some other techniques. Each recovered UL data symbol stream is an estimate of the data symbol stream sent by the corresponding wireless station. The RX data processor 242 processes (e.g., demodulates, deinterleaves, and decodes) the stream according to the rate for each recovered uplink data symbol stream to obtain decoded data. The decoded data of each wireless STA can be provided to a data sink 244 for storage and / or a controller 230 for further processing.

[0060] On the DL, at AP 110, TX data processor 210 receives N packets scheduled for downlink transmission from data source 208. DL The TX data processor 210 processes (e.g., encodes, interleaves, and modulates) the traffic data of each wireless station based on the rate selected for each wireless station. The TX data processor 210 processes (e.g., encodes, interleaves, and modulates) the traffic data of each wireless station based on the rate selected for each wireless station. DL The wireless stations provide N DL TX spatial processor 220 performs N DL The DL data symbol streams are spatially processed (such as precoding or beamforming, as described in the present disclosure) and are N ap The antennas provide N ap Each transceiver 222 receives and processes a corresponding transmit symbol stream to generate a DL signal. ap The transceiver 222 provides N ap DL signals for N ap The antenna 224 transmits to the wireless STA.

[0061] At each wireless STA 120, N sta,m The antenna 252 receives N signals from the AP 110. ap Each transceiver 254 processes the received signal from an associated antenna 252 and provides a received symbol stream. RX spatial processor 260 processes the received signal from N sta,m The N transceivers 254 receive sta,m The RX data processor 270 performs receiver spatial processing on the symbol streams and provides a recovered DL data symbol stream for the wireless station. The receiver spatial processing is performed based on CCMI, MMSE, or some other technique. The RX data processor 270 processes (e.g., demodulates, deinterleaves, and decodes) the recovered DL data symbol stream to obtain decoded data for the wireless station.

[0062] At each wireless STA 120, the channel estimator 278 estimates the DL channel response and provides a DL channel estimate, which may include a channel gain estimate, an SNR estimate, a noise variance, etc. Similarly, the channel estimator 228 estimates the UL channel response and provides a UL channel estimate. The controller 280 of each wireless STA is generally based on the wireless station's downlink channel response matrix H dn,m The controller 230 derives the spatial filter matrix of the wireless station based on the effective UL channel response matrix H up,effThe AP's spatial filter matrix is ​​derived. The controller 280 of each wireless STA may send feedback information (e.g., downlink and / or uplink eigenvectors, eigenvalues, SNR estimates, etc.) to the AP. Controllers 230 and 280 also control the operation of various processing units at AP 110 and wireless STA 120, respectively.

[0063] Multilink Device Overview

[0064] A multi-link device (MLD) generally refers to a single device or equipment that includes two or more station (STA) instances or entities, implemented in the physical (PHY) / medium access control (MAC) layer, and configured to communicate on separate wireless links. In some examples, each MLD may include a single higher-level entity, such as a MAC service access point (SAP), which may allocate MAC protocol data units (MPDUs) for transmission by separate STA instances.

[0065] Figure 3 A block diagram of an example MLD deployment 300 is shown. Figure 3 As shown, an access point (AP) MLD 302 can communicate with a non-AP MLD 304. Each of the AP MLD and the non-AP MLD may include at least two STA entities 314 (hereinafter also referred to as "STA"), which can communicate with the associated STAs of the other MLD. In the AP MLD, the STA may be an AP STA 312 (a STA that acts as an AP or simply "AP"). In the non-AP MLD, the STA may be a non-AP STA (a STA that does not act as an AP). As also described above, the MLD may utilize multi-link aggregation (MLA) (which includes packet-level aggregation), whereby MPDUs from the same service ID (TID) may be sent via two or more wireless links.

[0066] Various communication modes may be used in MLD implementations. For example, MLDs may communicate in an asynchronous (Async) mode or a synchronous (Sync) mode. Asynchronous mode provides flexibility to adapt to channel loading, allowing the MLD to asynchronously perform channel access, send, and receive data via multiple links. However, if there is RF leakage between channels, synchronous mode may be preferred because synchronous transmission on all links is not affected by RF leakage.

[0067] In asynchronous mode, the STA / AP can count down on both radio links (e.g., through random backoff (RBO)). The start / end of the physical layer convergence protocol (PLCP) protocol data unit (PPDU) can occur independently on each radio link. Therefore, asynchronous mode can potentially provide latency and aggregation gains. In some cases, relatively complex (and costly) filters may be required (e.g., in the case of 5GHz+6GHz aggregation).

[0068] In synchronous mode, STA / AP can also perform backoff countdown on multiple wireless links as part of the channel access process. If the first link gains access to the medium through the channel access process, multiple links can send PPDUs simultaneously. Therefore, this mode may require some restrictions to minimize intra-device interference.

[0069] Synchronous mode can work in 5GHz+6GHz aggregation and may require relatively low filter performance while still providing latency and aggregation gains. However, due to the tiled architecture of STAs, such latency and aggregation gains may be difficult to achieve.

[0070] Although not shown, the third communication mode may include a basic (e.g., multi-master with single link transmission) mode. In the basic mode, the STA / AP may also count down on two wireless links. However, the transmission may only occur on the wireless link that obtains access to the medium. The other wireless link may be blocked by in-device interference greater than -62 decibels per milliwatt (dBm). In this mode, aggregation gain may not be achieved.

[0071] Aspects related to wireless LAN connect-then-disconnect switching

[0072] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for make-before-break handover in a wireless local area network.

[0073] As mentioned above, conventional wireless communication systems generally only support a disconnect-before-connect handover process, requiring STAs to perform an association process when roaming between multiple APs. This approach generates data interruption and additional delays during the handover process.

[0074] However, aspects of the present disclosure support a make-before-break handover process, which can avoid data interruption during handover and reduce delay.

[0075] Aspects of the present disclosure may be used, for example, in Figure 4 The architecture shown is implemented in a multi-link operation (MLO) architecture. Figure 4The MLO architecture may allow non-collocated APs to be attached to a single AP MLD 402. In this manner, the AP MLD may be considered a logical entity that is physically collocated with any one of the set of non-collocated APs 412 attached to the AP MLD.

[0076] 5A-5C illustrate example operations before, during, and after make-before-break switching according to aspects of the present disclosure.

[0077] As shown in FIG5A , before switching, a STA (e.g., STAx) within the MLO architecture has an active link only with the serving AP (AP1). At this point, the link with AP1 is the only link in the enabled link set, and the data path is routed to AP1. AP1 hosts the MLD context 502 for the client (e.g., STAx). Although AP1 and the target AP (AP2) are collocated and can be attached to the associated link set, AP2 is not in the enabled link set at this time.

[0078] However, as shown in FIG5B , as STAx moves toward AP2, the link to AP2 can be enabled during the make-before-break switch. As shown, this transition can occur where STAx moves closer to AP2. At this point, AP2 is added to the enabled link set along with AP1, and both AP1 and AP2 exchange packets to the client (because the link with AP2 was established before the link with AP1 was disconnected). Optionally, as part of the transition, AP1 copies / forwards packets to AP2.

[0079] As shown in Figure 5C, after the transition, AP1 is removed from the enabled link set and the data path is rerouted to AP2. At this point, AP2 hosts the MLD context of the client.

[0080] By implementing the multi-AP association described herein, data interruption during switching (e.g., MSDU loss, duplicated MSDU, or out-of-order MSDU delivery) can be mitigated. Therefore, delays and interruptions in typical MLO reassociation or 4-way handshake processes are avoided. On the contrary, during switching, interruptions and delays on the data path are minimal. Multi-AP associations also do not require association or related security steps. An implementation of multi-AP association can allow mobility between a large number of APs (e.g., a single floor covered by 50 APs in an enterprise network).

[0081] According to aspects of the present disclosure, make-before-break switching may be implemented within a multi-link architecture according to certain extensions.

[0082] In one example, a client (e.g., STA) may be allowed to associate with a subset of APs (the associated link set), and then some mechanism to add / remove APs to / from the associated link set. In this case, a non-AP MLD (e.g., STA) cannot request and establish all links at the same time. When a STA is deployed, only some APs are within the range of the STA, so not all links can be used at the same time, and therefore may not need to be established at the same time. Therefore, the associated link set defined for a given STA can allow for better multi-AP association within a multi-link architecture.

[0083] In another example, certain mechanisms may be enabled so that the distribution system (DS) / backhaul is directly connected to the AP serving the client (STA). This may mean that the backhaul / DS attachment point moves when the client moves from one AP to another.

[0084] As described above, multiple non-collocated APs within a network topology may be attached to a single AP MLD. There may be a large number of APs. For example, all APs in a corporate floor may belong to the same AP MLD. Non-AP MLDs (e.g., STAs) perform handoffs as they move across corporate floors.

[0085] According to certain aspects, MLO association and authentication may be implemented to enable non-AP MLDs to associate with AP MLDs. For example, 11be ML discovery may be extended, and ML authentication and association, pairwise transient key security association (PTKSA), block acknowledgement (BA), etc. may be reused. In some cases, an affiliated AP may notify its neighboring APs in its beacon (and these neighboring APs may be identified by the STA as potential handover targets).

[0086] As shown in FIGS. 6A-6C , according to certain aspects, an associated link set may be maintained. The associated link set is a subset of the attached links that are currently "associated" with a non-AP MLD. To maintain the associated link set, once an attached AP is in range (with a threshold / time lag), it may be added to the associated link set. Once an attached AP is out of range (with a threshold / time lag), it may be removed from the set. For example, existing 11be ML link reconfiguration may be used to dynamically add / remove links without (re)association. The enabled link set described herein is a subset of the associated link set.

[0087] 6A-6C illustrate example associated linksets and example enabled linksets before, during, and after make-before-break handover. In the example, STA1 (non-AP MLD) moves to the right.

[0088] 6A shows an example associated link set and an example enabled link set before make-before-break switching. Here, AP2-AP5 is part of the associated link set. In this example, AP3 is currently serving STAs, so that (the link to AP3) AP3 is the only member of the enabled link set and hosts MDL context 502.

[0089] As shown in Fig. 6B, when the STA moves, the link to AP4 is enabled without interrupting the link to AP3. Here, the redundant link can be used for duplicated data exchange during handover.

[0090] As shown in Figure 6C, after the handoff, the MLD context 502 is relocated from AP3 to AP4. In this example, AP3 is removed from the enabled link set, AP2 is removed from the associated link set, and AP6 is added to the associated link set.

[0091] According to certain aspects, pre-switching preparation can occur on the network side. In some cases, the AP MLD can detect the presence of a switching condition. In other cases, the switch can be triggered by the non-AP MLD itself (e.g., using an auxiliary radio to find a target AP). Once the switch is decided, the network can initiate the switch transition phase. During the switch transition phase, duplicate packets can be sent on multiple links for reliability and to reduce latency. Existing 11be MLD procedures and signaling can be used to remove any duplicate packets. The MLD context (e.g., association, authentication, BA) can be relocated to the new (anchor) AP and the duplicate transmission can be terminated.

[0092] Implementations of the techniques described herein may reuse certain existing 11be mechanisms. For example, ML establishment (e.g., association and authentication, PTKSA, BA, etc.) and ML reconfiguration (add / remove links) of enabled link sets may be reused. In addition, AP beacons may include neighboring APs. Associated link sets may be maintained. Medium access control (MAC) for serving AP (SAP) and MLD contexts may be maintained.

[0093] exist Figure 7 An example connect-before-disconnect process is shown in FIG. As shown in the figure, in the initial state (1), a gateway (GW) 704 may be connected to AP1, and all traffic passes through AP1. In this example, AP1 has an uplink (UL) reordering buffer (ROB) 702.

[0094] As shown in (2), the handover to AP2 is started. First, downlink (DL) duplication is initiated, where AP1 can start duplicating DL packets by forwarding the DL packets to AP2. Upon receiving the DL packets, AP2 sends the DL packets to STA2. UL duplication can also start when STA2 starts duplicating UL packets and sends the duplication to AP2, for example, over the air (OTA Sig 1). In one case, AP2 buffers all UL packets received at the ROB without forwarding the packets to the gateway (otherwise, the packets may be received out of order at the gateway). In an alternative case, AP2 forwards all received UL packets to AP1 for reordering.

[0095] As shown in (3), after the UL packet is forwarded, the MLD context can be relocated. The MLD context location is based on an agreed timer and UL sequence number (SN) value, etc. The MLD context may include any one of an association context, a security context, a block ACK (BA) session, a TID to link mapping, a DL packet buffer, a ROB, and a PN (packet number). During MLD context relocation, AP1 stops sending UL packets to the gateway and then sends the MLD context to AP2, and STA1 may stop transmission to AP1 (OTA Sig2).

[0096] After repositioning, at (4), AP2 can receive uplink packets and combine them with its local RO buffer. AP2 starts sending UL packets to the gateway, and AP2 stops forwarding UL packets to AP1 (if it has been forwarding packets to AP1). In some cases, AP2 sends a "switch path layer 2 (L2) message" to the gateway, and the gateway switches the data path to AP2. To complete the switching process, AP2 can send a switching "complete message" to AP1. AP1 stops DL transmission and clears any unsent DL packets.

[0097] Respectively Figure 8 and Fig. 9 As shown, the connect-before-disconnect switching can be initiated by the network or the client respectively.

[0098] like Figure 8 As shown, an initial state in which a non-AP MLD STA is served by a serving AP (at block 1) is assumed. In this case, the serving AP may enable handover by sending a message to the STA to enable the link to the target AP (at block 2). Operation then proceeds as described above, where the MLD begins using both links during the handover. To signal the end of the handover, the target AP may send a message to AP1 for the STA to disable link 1, and may send a message to AP2 that the handover is complete.

[0099] like Fig. 9As shown, for the make-before-break handover process initiated by the client, the STA may send a message to the serving AP to enable link 2 to the target AP. Other operations may be performed as described above with reference to the make-before-break handover process initiated by the network.

[0100] Aspects related to data path switching

[0101] Certain aspects of the present disclosure provide techniques that can help enable seamless roaming of clients between APs without reassociation. This is beneficial because reassociation typically results in a reset of a block acknowledgment (BA) sequence number (SN) and may result in packet loss. The techniques proposed herein may result in zero or minimal packet loss.

[0102] In some cases, the techniques proposed in this article can help improve the user experience without significantly changing the backhaul signaling and corresponding controller operations. These techniques can take into account different types of services, such as XR services that can tolerate some packet loss, and file transfer scenarios that generally cannot tolerate packet loss.

[0103] These techniques can be applied to perform data path switching for various scenarios. These scenarios may include a make-before-break handover, where no data forwarding is performed. In this case, packet delivery during the transition (from the source AP to the target AP) can be best-effort based, allowing the source AP to drain packets (e.g., from a downlink queue) while the target AP is being established. This best-effort approach may result in packet drops. These scenarios may also include a partial make-before-break handover with MSDU level forwarding (with some potential MPDU level packet drops), a full make-before-break handover with both MPDU level and MSDU level forwarding, and scenarios with simultaneous packet delivery from multiple APs.

[0104] As will be described in further detail below, the data path switching proposed herein may involve the transfer of management and context between the source AP and the target AP. The management context may include information about the security and association of the station. The data context may include information about the service, such as sequence numbers and packet numbers.

[0105] The techniques proposed herein can be applied to various scenarios, including station-initiated (or client-initiated) handover scenarios and network-initiated handover scenarios. The techniques proposed herein can also be applied to handover scenarios involving devices of different capabilities, such as single radio stations and multi-radio stations.

[0106] As used herein, handover generally refers to the process of a wireless node moving from one (physically different) serving AP device (called source AP) to another serving AP device (called target AP). Other terms may also be used to refer to the same or similar process, such as seamless roaming.

[0107] The wireless node that switches (or roams) from the source AP to the target AP can be any type of device that supports switching or seamless roaming, such as a non-AP MLD or a non-AP STA (e.g., a client device). The source AP and / or the target AP can be any type of AP device, such as a standalone AP or an AP MLD.

[0108] In the handover scenario described herein, both the source AP and the target AP may be attached to a single mobility domain (SMD) entity, such as an SMD AP MLD. In this case, the SMD entity generally refers to a logical entity that includes more than one non-collocated AP devices, so that non-AP devices associated with the SMD entity can seamlessly roam between AP devices attached to the SMD entity (e.g., without the need for reassociation). In this case, the AP device (attached to the SMD entity) may be an AP MLD that includes one or more attached APs or single-link APs. The non-AP device may be a non-AP MLD that includes one or more attached non-AP STAs or single-link non-AP STAs.

[0109] The source AP and the target AP can be attached to different (normal or non-SMD) AP MLDs. The SMD AP MLD can be similar to the normal AP MLD in that it can control multiple APs attached to it. However, one difference is that the APs attached to the SMD AP MLD can be in different locations (non-collocated), while the APs attached to the same normal AP MLD are usually in the same location (collocated).

[0110] An example of an SMD entity is an SMD MLD, which may refer to a logical entity that may reside, for example, on a network controller or a service AP MLD of a specific client. For the latter case, the physical AP that provides (activates / operates) the SMD MLD function may be different for different clients, so the physical location of the SMD MLD may be different for different clients. In addition, some operations or functions may be divided between AP MLD and SMD MLD. For example, functions related to association context, block acknowledgement (BA) and / or security may reside on the SMD MLD of a specific client, while other functions related to the link ID may be based on the service AP MLD. This is in contrast to traditional stations (e.g., legacy clients) such as 802.11-compatible non-AP MLDs, in which these functions may all reside on the physical AP MLD that serves the non-AP MLD. Although the present disclosure refers to the entity that provides the above functions as an SMD MLD, entities that provide the same or similar functions may be referred to by other names.

[0111] Fig.10 An example call flow 1000 for a station initiated handoff in accordance with certain aspects of the present disclosure is depicted. The example assumes that a client station (STA) 1020 initiates a handoff from a source AP (AP1 1010-1) to a target AP (AP2 1010-2), both of which are affiliated with a SMD MLD.

[0112] As shown in 1002, the STA may initially communicate with AP1 via a first link (Link 1). As shown in 1004, the STA may initiate a handover (HO) and may send an HO indication to AP1. As described below, the HO indication may be sent in a message referred to as a Roaming Notification Initiation (RAI) message. Certain other types of messages (in addition to RAI messages) referred to by different names may also convey HO indications or similar types of signaling to notify the initiation of a handover or seamless roaming.

[0113] After receiving the HO indication, AP1 may transfer context to AP2 to prepare AP2 to serve the STA. As described above, the context may include management and data context. In some cases, AP1 may indicate that the context transfer has been performed, for example, with a response to the HO indication, which may also indicate that the second link (link 2) is enabled. As shown in 1006, after receiving the response, the STA may communicate with AP2 via link 2. As shown in 1008, the STA may disable link 1 with AP1.

[0114] Although call flow 1000 is a relatively high-level description of a client-initiated HO, Fig.11 The call flow diagram 1100 and Fig.12The call flow diagrams 1100 and 1200 provide additional signaling details for example scenarios assuming a single radio STA and a multi-radio STA, respectively. For example, the call flows 1100 and 1200 include additional details about the interaction between AP1 and AP2 and the controller of the SMD MLD. The controller may be Figure 1 The example of the system controller 130 of the SMD AP MLD is shown in FIG. 1 . The controller can generally be used to manage APs attached to the SMD AP MLD, for example, to manage the addition and removal of APs to the SMD AP MLD. The controller can also be used to route data between the network and the STA via the APs attached to the SMD AP MLD. When the STA moves between the source AP and the target AP, the signaling mechanism proposed in this article can allow data path switching with little or no packet loss without significantly changing the controller or backhaul signaling.

[0115] Fig.11 An example call flow 1100 for station initiated handover in a single radio scenario in accordance with certain aspects of the present disclosure is depicted. The example assumes that a STA 1120 initiates a handover from a source AP1 1110-1 to a target AP2 1110-2, both of which are affiliated with a SMD MLD. Fig.11 The call flow 1100 includes relative to Fig.10 Some additional details of the call flow, such as the interaction between AP1 1110-1 and AP2 1110-2 and the controller 1130 of the SMD MLD.

[0116] As shown in (1), MLD establishment is performed and a link is established between STA and AP1. For example, during MLD establishment, a signaling exchange between STA and AP1 may be involved to negotiate the capabilities and operating parameters of one or more links. As shown in (2), in a first state after MLD establishment, the link with AP1 is enabled and the controller routes DL traffic to AP1. As shown in (3), in this state, UL traffic is also routed from STA to the controller via AP1. As shown in (4) and (5), a link can be added for AP2, resulting in a second state with a set of links that enable AP1 and disable AP2, where the controller still routes DL traffic to AP1. Adding the link for AP2 while the link with AP1 is still enabled can help reduce delays when the STA is actually processed to AP2 with little or no packet loss.

[0117] As shown in (6), the STA may decide to initiate a HO. The decision may be based on a trigger, such as a change in channel conditions or some traffic-related metrics when the STA moves (e.g., from AP1 to AP2). In some cases, as shown in (7), the STA may drain outstanding MPDUs to AP1 (e.g., to flush the UL queue).

[0118] As shown in (8), in response to the HO decision, the STA may send a Roaming Notification Initiation (RAI) message. The RAI message may be sent as a separate / dedicated frame (e.g., a management / control frame), in a data frame, and / or as part of a header (e.g., in an A-CTL field). In some cases, the RAI may have information about the time the STA can communicate with the current AP before moving. This may be referred to as a handover deadline (HO_deadline).

[0119] As shown in (9), context transfer to AP2 can be enabled via SMD internal signaling. The context information may include, for example, a target last SN on AP1. This information may allow AP2 to know and / or determine the starting SN when it starts serving the STA. AP2 may use the target last SN to determine which packets to start with when AP2 starts serving the client. AP1 may indicate the target last SN based on the assumption that there is no MPDU level forwarding, so the MSDU will arrive at AP2 and AP2 needs to use a new SN and needs to know where to start. In order to determine the target last SN, AP1 may predict the last SN that AP1 will deliver to the STA. For example, in the worst case, AP1 may assume the same SN (assuming no more packets are successfully delivered), or may select a lower SN, for example, if multiple MPDUs are aggregated in an aggregate MPDU (AMPDU). As described below, the BAR from AP1 may address this issue, allowing AP1 to know what packets the STA received.

[0120] Link enabling may occur, as shown at (10), where an L2 update is provided to the controller. The update may indicate to the controller that AP2 is (or will be) hosting a client STA, so that it may begin forwarding DL data to AP2, as shown at (11), without disabling its link to AP1. Not disabling the link to AP1 may allow AP1 to continue delivering packets to the STA while the controller begins routing packets through AP2. In other words, DL data may be buffered at AP2.

[0121] As shown in (12), because the link with AP1 is not disabled, AP1 can flush its remaining queued packets. AP1 can attempt to flush all or only some of its packets. In some cases, whether AP1 flushes all or only some may depend on various factors, such as link quality. For example, if the link quality is at or above a threshold, AP1 may decide to flush all of its packets. If the link quality is not good, AP1 may try to flush what it can based on a deadline (or timeout value). As described above, the goal may be seamless to the user. Therefore, the decision on how much / how to flush may depend on quality of service (QoS) and / or other considerations. In some cases, the STA can indicate in the RAI the preferences that AP1 considers when deciding how much to flush. For example, if moving quickly to the target is more important to the STA (and some packet loss is tolerable), the STA can indicate a deadline (timeout value) in the RAI. In this case, switching the STA to AP2 can be considered more important than flushing all packets. The STA can indicate this as part of the RAI, for example by indicating a deadline. In this case, AP1 can attempt to flush the packets, but only for the timeout indicated by the deadline.

[0122] As shown in (13), after flushing the DL packet, AP1 can indicate to the STA that the link to AP1 can be disabled and / or the link to AP2 can be enabled. In some cases, one or both of these indications can be provided in a response to the RAI, which can be referred to as a roaming notification response (RAR). As shown in (14), once the link to AP2 is enabled, the controller and the STA can exchange UL / DL data via AP2. As shown in (15), in this state, the link with AP1 is disabled and the link with AP2 is enabled.

[0123] As shown in (16), in some cases, AP1 can send a block acknowledgement request (BAR) to the STA. This BAR can help avoid the STA from getting stuck on sequence numbers if all packets were not flushed at (12). The BAR can allow the STA to respond with an indication of which packets were received and avoid holes / lost packets in the sequence number space.

[0124] As mentioned above, a timeout may help if the link is bad and there are multiple retries, which will increase the latency of the handover. The timeout may allow AP1 to drop the remaining packets after a certain timeout. The timeout (deadline) value can be determined based on how fast the client expects to move from AP1 to AP2. Different use case scenarios may affect the timeout value. For example, in the XR use case, fast handover may be more important and a certain amount of packet loss can be tolerated.

[0125] Fig.12 An example call flow 1200 for station initiated handover in a multi-radio scenario in accordance with certain aspects of the present disclosure is depicted. The example assumes that STA 1220 initiates handover from source AP1 1210-1 to target AP2 1210-2, both of which are affiliated with SMD MLD and controller 1230.

[0126] As shown in the figure, operations (1)-(8) can be compared with the above reference Fig.11 The operations are the same or similar to those described in the call flow 1100. However, after the STA sends the RAI to notify the station to initiate the handover, there are multiple different operations for enabling the radio. For example, as shown in (9), the link enablement of AP2 can occur (immediately) without waiting for the context transfer of (9a), thereby allowing the controller to start forwarding DL data to AP2, as shown in (10).

[0127] Given multiple radios, a link with AP2 may be enabled, as shown in (11). As described above, AP2 link enablement may be indicated in a RAR message. As shown in (12), in this state, both the link with AP1 and the link with AP2 are enabled. Therefore, both AP1 and AP2 may send DL data. As shown in (13), once the link to AP2 is enabled, the controller and STA may exchange UL and DL data with the STA via AP2.

[0128] In some cases, the STA may send an acknowledgment (ACK) to AP1 to indicate that it successfully received the RAR message. In this case, AP1 may inform AP2 whether it received the RAR ACK from the STA. If AP1 does not receive an ACK (delivery failure of the RAR message), AP2 may include information that may have been provided in the RAR message so that the STA can still properly establish a state as if it had received the RAR message from AP1.

[0129] Given multiple radios of a client STA, as shown in (14), draining DL packets from AP1 can occur simultaneously with providing DL / UL packets to / from AP2. As described above, there may be a timeout mechanism to stop attempts to flush DL data from AP1 after a certain period of time. In some cases, to speed up the completion of the handover, UL traffic may be sent only to AP2 after the AP2 link is enabled.

[0130] As shown in (15), after flushing the DL packet, AP1 can indicate that the STA can disable the link to AP1. As shown in (16), in this state, the link with AP1 is disabled, the link with AP2 is enabled, and the controller routes the DL traffic to the STA via AP2. As shown in (17), in some cases, AP1 can send a block acknowledgement request (BAR) to the STA. As shown in the above reference Fig.11 As described above, if (14) does not flush all packets, BAR can help avoid STAs from getting stuck with sequence numbers. BAR can allow STAs to respond with an indication of which packets were received and avoid holes / lost packets in the sequence number space.

[0131] In some cases, the multiple radio scenario may use different timeouts than the single radio scenario. For example, the handover deadline may be more relaxed because AP2 can start serving STAs sooner without having to wait for AP1 (as in the single radio scenario).

[0132] Fig.13 An example call flow for a network initiated handover according to certain aspects of the present disclosure is depicted. The example assumes a network initiated handover of a STA 1320 from a source AP1 1310-1 to a target AP2 1310-2, both of which are affiliated with a SMD MLD. The signaling is similar to Fig.10 , except that source AP1 assumes the role of HO initiator. In other words, AP1 sends a HO indication to the STA, and the STA sends a corresponding response. Network-initiated handover may have benefits, for example, because the AP may have consideration information that the STA may not have, such as the overall network load and / or the relative load of one or more potential target APs.

[0133] As shown in 1302, similar to Fig.10 In the scenario shown, the STA may initially communicate with AP1 via link 1. As shown in 1304, AP1 may then initiate HO and may send a HO indication to the STA (e.g., via a RAI message). After sending the HO indication, AP1 may transfer a context to AP2 to prepare AP2 to serve the STA. In this case, when the STA is ready to enable link 2 (e.g., after draining UL packets to AP1), the STA may signal AP1 (e.g., via a RAR message). As shown in 1306, after sending a response, the STA may communicate with AP2 via link 2. As shown in 1308, the STA may disable link 1 with AP1.

[0134] Although call flow 1300 is a relatively high-level description of a network-initiated HO, Fig.14 The call flow diagram 1400 and Fig.15 The call flow diagram 1500 provides additional signaling details for example scenarios assuming a single radio STA and a multi-radio STA, respectively. For example, the call flows 1400 and 1500 include additional details about the interaction between AP1 and AP2 and the controller of the SMD MLD.

[0135] Fig.14 An example call flow for a network initiated handover in a single radio scenario according to certain aspects of the present disclosure is depicted. The example assumes a network initiated handover of a STA 1420 from a source AP1 1410-1 to a target AP2 1410-2, both of which are attached to a SMD MLD and a controller 1430.

[0136] As shown in the figure, operations (1)-(5) can be compared with the above reference Fig.11 and Fig.12 The operations described in call flows 1100 and 1200 are the same or similar. However, as shown in (6), AP1 sends RAI. As shown in (7), STA can discharge unprocessed MPDUs to AP1.

[0137] As shown in (8a), after AP1 sends the RAI, context transfer to AP2 can be enabled via SMD internal signaling. Link enablement can occur, as shown in (8), where an L2 update is provided to the controller indicating that AP2 is (will be) hosting the client STA so that it can start forwarding DL data to AP2, as shown in (9). As shown in (10), AP1 can flush its remaining queued packets.

[0138] As shown in (11), after flushing the DL packets, AP1 can indicate to the STA that the link to AP1 can be disabled and / or the link to AP2 can be enabled. As shown in (12), once the link to AP2 is enabled, the controller and the STA can exchange UL / DL data via AP2. As shown in (13), in this state, the link with AP1 is disabled and the link with AP2 is enabled. As shown in (14), in some cases, AP1 can send a block acknowledgement request (BAR) to the STA. If not all packets are flushed at (10), the BAR can help avoid the STA from being stuck in sequence numbers. The BAR can allow the STA to respond with an indication of which packets are received and avoid holes / lost packets in the sequence number space. As in the above scenario, certain operations may be subject to timeouts, such as timeouts determined by a switching deadline. For example, at (7), the RAI can indicate a deadline for determining when the STA attempts to drain the MPDU.

[0139] Fig.15 An example call flow for network initiated handover in a multi-radio scenario according to certain aspects of the present disclosure is depicted. The example assumes a network initiated handover of a STA 1520 from a source AP1 1510-1 to a target AP2 1510-2, both of which are affiliated with a SMD MLD and a controller 1530.

[0140] As shown in the figure, operations (1)-(8) can be compared with the above reference Fig.14 The operations are the same or similar to those described in call flow 1400. However, after AP1 sends the RAI to notify the network to initiate the switch, there are different operations with multi-radio enablement. For example, as shown in (9), link enablement of AP2 can occur after the STA discharges the MPDU via a RAR message from the STA, resulting in a state where both the link with AP1 and the link with AP2 are enabled, as shown in (10). Enabling the link of AP2 allows the controller to start forwarding DL data to AP2, as shown in (11). In some cases, the client can send a RAR and AP1 can send link enablement of AP2.

[0141] Given multiple radios of a client STA, as shown in (12), draining DL packets from AP1 may occur simultaneously with providing DL / UL packets to / from AP2. As described above, there may be a timeout mechanism to stop attempts to flush DL data from AP1 after a certain period of time. In some cases, to speed up the completion of the handover, UL traffic may be sent only to AP2 after the AP2 link is enabled.

[0142] As shown in (13), after flushing the DL packets, AP1 can instruct the STA that the link to AP1 can be disabled. As shown in (14), in this state, the link with AP1 is disabled, the link with AP2 is enabled, and the controller routes the DL traffic to the STA via AP2. As shown in (15), in some cases, AP1 can send a block acknowledgement request (BAR) to the STA. As described above, if (12) does not flush all packets, the BAR can help avoid the STA from being stuck with a sequence number.

[0143] Similar to the above scenario, at (7), the RAI may indicate a HO_deadline, which may be used to set a timeout mechanism, for example, for a STA to refresh an MPDU. In some cases, the STA may receive an ACK for the RAR sent at (9). If no ACK is received, there are multiple options for how to proceed. For example, AP1 may have a timeout mechanism to wait for a RAR after sending out the RAI. Assuming that the timeout mechanism is triggered (timeout after the first timeout period, timeout1), AP1 may send what may be considered a "potential" link enable to AP2, such that AP2 is ready to receive packets from the STA after a waiting period called PT2. If this period passes and AP2 does not receive a RAR from the STA, AP2 may remove the link enable.

[0144] In some cases, if STA does not receive an ACK from AP1, STA may send a RAR to AP2 after a second timeout period, timeout2. Timeout2 may be set to be later than timeout1, so that STA will send a RAR to AP2 only after AP2 is ready. However, this timeout2 may be set to expire earlier than timeout1 plus PT2, so that AP2 does not exit the waiting period before STA sends a RAR. After AP2 receives the RAR from STA, AP2 should inform AP1 and continue L2 updates with the controller. After being informed, AP1 may continue to perform operations (12) and (13), which may also have a timeout mechanism.

[0145] Example Operation

[0146] Fig.16 An example of a method 1600 for wireless communication at a first wireless station is shown. In some examples, the first wireless station is such as Figure 1 and Figure 2 STA 120 station.

[0147] The method 1600 begins at step 1605 by communicating with a first AP attached to an MLD via a first link. In some cases, the operation of this step involves or can be performed by a circuit for communication and / or code for communication, such as reference Fig.23 As described.

[0148] The method 1600 then proceeds to step 1610, enabling a second link with a second AP attached to the MLD. In some cases, the operation of this step involves or can be performed by a circuit for enabling and / or a code for enabling, such as referring to Fig.23 As described.

[0149] The method 1600 then proceeds to step 1615, during the handover of the first wireless station from the first AP to the second AP, communicating with the first AP via the first link and communicating with the second AP via the second link. In some cases, the operation of this step involves or can be performed by a circuit for communication and / or a code for communication, such as reference Fig.23 As described.

[0150] The method 1600 then proceeds to step 1620, disabling the first link with the first AP after the handover is completed. In some cases, the operation of this step involves or can be performed by a circuit for disabling and / or a code for disabling, such as referring to Fig.23 As described.

[0151] In some aspects, when the second link is enabled, the second link is a member of an associated link set.

[0152] In some aspects, the method 1600 further includes adding a third link associated with a third AP attached to the MLD to the associated link set. In some cases, the operation of this step involves or can be performed by a circuit for adding and / or a code for adding, such as referring to Fig.23 As described.

[0153] In some aspects, the method 1600 further includes removing a fourth link associated with a fourth AP attached to the MLD from the set of associated links. In some cases, the operation of this step involves or can be performed by a circuit for removing and / or a code for removing, such as referring to Fig.23 As described.

[0154] In some aspects, the method 1600 further includes obtaining a beacon from the first AP. In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as referring to Fig.23 As described.

[0155] In some aspects, the method 1600 further includes identifying at least the second AP and the third AP based on the information in the beacon. In some cases, the operation of this step involves or can be performed by a circuit for identifying and / or a code for identifying, such as reference Fig.23 as described.

[0156] In some aspects, during switching, communicating with the first AP via the first link and communicating with the second AP via the second link includes at least one of: obtaining a duplicate first packet via both the first link and the second link; or outputting a duplicate second packet for transmission via the first link and the second link.

[0157] In some aspects, the method 1600 further includes obtaining signaling from the first AP instructing the wireless station to enable the second link, wherein the wireless station enables the second link after obtaining the signaling. In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as referring to Fig.23 as described.

[0158] In some aspects, the method 1600 further includes outputting a signaling to initiate the handover to the first AP for transmission, wherein the wireless station enables the second link after outputting the signaling. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 as described.

[0159] In some aspects, the method 1600 further includes obtaining signaling from the second AP indicating that the wireless station is to disable the first link, wherein the wireless station disables the first link after obtaining the signaling. In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as reference Fig.23 as described.

[0160] In one aspect, method 1600 or any aspect related thereto may be performed by, for example, Fig.23 The method 1600 may be performed by an apparatus of a communication device 2300, which includes various components operable, configured, or adapted to perform the method 1600. The communication device 2300 will be described in more detail below.

[0161] Notice, Fig.16 This is merely one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with the present disclosure.

[0162] Fig.17 An example of a method 1700 for wireless communication at a first AP is shown. In some examples, the first AP is an access point, such as Figure 1 and Figure 2 AP 110.

[0163] The method 1700 begins at step 1705, communicating with a wireless station via a first link during a handover of the wireless station from a first AP to a second AP, wherein the wireless station is associated with an MLD, and both the first AP and the second AP are attached to the MLD. In some cases, the operation of this step involves or can be performed by a circuit for communication and / or a code for communication, such as reference Fig.23 as described.

[0164] The method 1700 then proceeds to step 1710, outputting the context information of the MLD for transmission to the second AP. In some cases, the operation of this step involves or can be performed by circuitry for outputting and / or code for outputting, such as referring to Fig.23 as described.

[0165] The method 1700 then proceeds to step 1715, disabling the first link with the first wireless station after the handover. In some cases, the operation of this step involves or can be performed by a circuit for disabling and / or a code for disabling, such as referring to Fig.23 as described.

[0166] In some aspects, the context information of the MLD includes information about at least one of: an association context, a security context or a TID to link mapping, one or more BA sessions, a downlink packet buffer, an uplink packet reordering buffer, a SN, or a PN.

[0167] In some aspects, the method 1700 further includes outputting a beacon identifying at least the second AP for transmission. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 as described.

[0168] In some aspects, communicating with the wireless station during the handoff includes at least one of: outputting a replicated first packet for transmission to the wireless station and to the second AP via the first link; or obtaining a replicated second packet from the wireless station and from the second AP via the first link.

[0169] In some aspects, the method 1700 further includes reordering the copied second packet. In some cases, the operation of this step involves or can be performed by a circuit for reordering and / or a code for reordering, such as reference 1700. Fig.23 as described.

[0170] In some aspects, the method 1700 also includes outputting to the wireless station a signal indicating that the wireless station is to disable the first link for communicating with the second AP. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 As described.

[0171] In some aspects, the method 1700 further includes obtaining signaling from the wireless station to initiate the handover. In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as referring to Fig.23 As described.

[0172] In some aspects, the method 1700 further includes obtaining signaling from the second AP indicating that the handover is complete. In some cases, the operation of this step involves or can be performed by circuitry for obtaining and / or code for obtaining, such as reference Fig.23 As described.

[0173] In some aspects, context information of the MLD is output for transmission based on at least one of a timer or an uplink sequence number.

[0174] In one aspect, method 1700 or any aspect related thereto may be performed by, for example, Fig.23 The method 1700 may be performed by an apparatus of a communication device 2300, which includes various components operable, configured, or adapted to perform the method 1700. The communication device 2300 will be described in more detail below.

[0175] Notice, Fig.17 This is merely one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with the present disclosure.

[0176] Fig.18 An example of a method 1800 for wireless communication at a second AP is shown. In some examples, the second AP is an access point, such as Figure 1 and Figure 2 AP 110.

[0177] The method 1800 begins at step 1805, communicating with a wireless station via a second link during a handover of the wireless station from a first AP to a second AP, wherein the wireless station is associated with an MLD, and both the first AP and the second AP are attached to the MLD. In some cases, the operation of this step involves or can be performed by a circuit for communication and / or a code for communication, such as reference Fig.23 As described.

[0178] The method 1800 then proceeds to step 1810, where context information of the MLD is obtained from the first AP. In some cases, the operation of this step involves or can be performed by circuitry for obtaining and / or code for obtaining, such as referring to Fig.23 as described.

[0179] The method 1800 then proceeds to step 1815, outputting a signal indicating that the handover is complete for transmission to the first AP. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 as described.

[0180] In some aspects, the context information of the MLD includes information about at least one of: an association context, a security context or a TID to link mapping, one or more BA sessions, a downlink packet buffer, an uplink packet reordering buffer, a SN, or a PN.

[0181] In some aspects, the method 1800 further includes outputting beacons identifying one or more neighboring APs of the second AP for transmission. In some cases, the operation of this step involves or can be performed by circuitry for outputting and / or code for outputting, such as referring to Fig.23 as described.

[0182] In some aspects, communicating with the wireless station during the handoff includes at least one of: outputting replicated packets for transmission to the wireless station and to the first AP via the second link; or obtaining replicated packets from the wireless station and from the first AP via the second link.

[0183] In some aspects, the method 1800 further includes outputting the replicated packets for transmission to the first AP for reordering. In some cases, the operation of this step involves or can be performed by circuitry for outputting and / or code for outputting, such as reference Fig.23 as described.

[0184] In some aspects, the method 1800 further includes outputting a signal indicating the handover is complete to the first AP for transmission. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 as described.

[0185] In some aspects, the method 1800 further includes outputting signaling for the gateway to switch the data path from the first AP to the second AP for transmission. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0186] In one aspect, method 1800 or any aspect related thereto may be performed by, for example, Fig.23 The method 1800 may be performed by an apparatus of a communication device 2300, including various components operable, configured, or adapted to perform the method 1800. The communication device 2300 will be described in more detail below.

[0187] Notice, Fig.18 This is merely one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with the present disclosure.

[0188] Fig.19 An example of a method 1900 for wireless communication at a wireless node is shown. In some examples, the wireless node is a station such as Figure 1 and Figure 2 STA 120. In some examples, the wireless node is an access point, such as Figure 1 and Figure 2 AP110.

[0189] Method 1900 begins at step 1905, communicating with a first access point (AP) device attached to a single mobility domain (SMD) entity via a first link. In some cases, the operation of this step involves or can be performed by a circuit for communication and / or a code for communication, such as reference Fig.23 as described.

[0190] The method 1900 then proceeds to step 1910, outputting a first message for transmission to the first AP device, the first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to a second AP device attached to the SMD entity. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0191] The method 1900 then proceeds to step 1915, where, after obtaining a second indication that context information has been transmitted from the first AP device to the second AP device, the first AP device is communicated via the second link during the handover. In some cases, the operation of this step involves or can be performed by circuitry for communication and / or code for communication, such as reference 1914. Fig.23 as described.

[0192] The method 1900 then proceeds to step 1920, where after obtaining a third indication triggering the wireless node to disable the first link with the first AP device, the first link with the first AP device is disabled. In some cases, the operation of this step involves or can be performed by a circuit for disabling and / or a code for disabling, such as referring to Fig.23 as described.

[0193] In some aspects, the first message comprises a Roaming Notification Initiation (RAI) message.

[0194] In some aspects, the second indication and the third indication are received via a single message.

[0195] In some aspects, the first message also includes a fourth indication of a deadline for completing the handover.

[0196] In some aspects, the method 1900 further includes obtaining, prior to communicating with the second AP device, via the first link, a second message, wherein the second message confirms the first indication. In some cases, the operation of this step involves or can be performed by circuitry for obtaining and / or code for obtaining, such as referring to Fig.23 as described.

[0197] In some aspects, the method 1900 further includes obtaining one or more packets from the first AP device after outputting the first message for transmission. In some cases, the operation of this step involves or can be performed by circuitry for obtaining and / or code for obtaining, such as reference Fig.23 as described.

[0198] In some aspects, the method 1900 further includes obtaining a block acknowledgement (BA) request (BAR) from the first AP device. In some cases, the operation of this step involves or can be performed by circuitry for obtaining and / or code for obtaining, such as reference Fig.23 as described.

[0199] In some aspects, the method 1900 further includes outputting a BA for transmission in response to the BAR, the BA indicating a sequence number (SN) of one or more packets. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0200] In some aspects, communicating with the second AP device via the second link occurs prior to disabling the first link.

[0201] In one aspect, method 1900 or any aspect related thereto may be performed by, for example, Fig.23 The method 1900 may be performed by an apparatus of a communication device 2300, including various components operable, configured or adapted to perform the method 1900. The communication device 2300 will be described in more detail below.

[0202] Notice, Fig.19 This is merely one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with the present disclosure.

[0203] Fig. 20It is shown that in Figure 1 and Figure 2 An example of a method 2000 for performing wireless communications at a first access point (AP) device of AP 110.

[0204] The method 2000 begins at step 2005, communicating with a wireless node attached to a single mobility domain (SMD) entity via a first link, the first AP device and the second AP device both being attached to the SMD entity. In some cases, the operation of this step involves or can be performed by a circuit for communication and / or a code for communication, such as reference Fig.23 as described.

[0205] The method 2000 then proceeds to step 2010, where a first message is obtained from the wireless node, the first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to the second AP device. In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as reference 2010. Fig.23 as described.

[0206] The method 2000 then proceeds to step 2015, where the context information is outputted for transmission to the second AP device after obtaining the first message. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 as described.

[0207] The method 2000 then proceeds to step 2020, outputting a second indication for triggering the wireless node to enable a second link with the second AP device for transmission to the wireless node. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 as described.

[0208] The method 2000 then proceeds to step 2025, outputting a third indication for transmitting to the wireless node that triggers the wireless node to disable the first link with the first AP device. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 as described.

[0209] In some aspects, the first message comprises a Roaming Notification Initiation (RAI) message.

[0210] In some aspects, the context information includes information about at least one of: an association context, a security context or traffic identifier (TID) to link mapping, one or more block acknowledgement (BA) sessions, a downlink packet buffer, an uplink packet reordering buffer, a sequence number (SN), or a packet number (PN).

[0211] In some aspects, the second indication and the third indication are sent via a single message.

[0212] In some aspects, the method 2000 further includes outputting a second message confirming the first indication for transmission to the wireless node before sending the first indication. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 as described.

[0213] In some aspects, the method 2000 further includes, after obtaining the first message, outputting one or more packets from the queue to the wireless node to discharge the (e.g., downlink) queue for transmission before the handover is completed. In some cases, the operation of this step involves or can be performed by circuitry for outputting and / or code for outputting, such as reference Fig.23 as described.

[0214] In some aspects, the method 2000 also includes outputting a block acknowledgement (BA) request (BAR) to the wireless node for transmission. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0215] In some aspects, the method 2000 also includes obtaining a BA in response to the BAR, the BA indicating whether the wireless node has received one or more packets with corresponding one or more sequence numbers (SN). In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as reference Fig.23 as described.

[0216] In some aspects, the method 2000 further includes including the information from the BA in the context information output for transmission to the second AP device. In some cases, the operation of this step involves or can be performed by a circuit for including and / or a code for including, such as reference Fig.23 as described.

[0217] In some aspects, at least one of: the first message also includes an indication of a deadline for completing the handoff; the deadline indicates a time when the first AP device attempts to send one or more packets from the queue to the wireless node; or the queue is empty before the handoff is completed.

[0218] In some aspects, the second indication is output for transmission before the third indication is output for transmission.

[0219] In one aspect, method 2000 or any aspect related thereto may be performed by, for example, Fig.23The method 2000 may be performed by an apparatus of a communication device 2300, including various components operable, configured or adapted to perform the method 2000. The communication device 2300 will be described in more detail below.

[0220] Notice, Fig. 20 This is merely one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with the present disclosure.

[0221] Fig.21 An example of a method 2100 for wireless communication at a wireless node is shown. In some examples, the wireless node is a station such as Figure 1 and Figure 2 STA 120. In some examples, the wireless node is an access point, such as Figure 1 and Figure 2 AP110.

[0222] The method 2100 begins at step 2105 by communicating with a first access point (AP) device attached to a single mobility domain (SMD) entity via a first link. In some cases, the operation of this step involves or can be performed by a circuit for communication and / or a code for communication, such as reference Fig.23 as described.

[0223] The method 2100 then proceeds to step 2110, where a first message is obtained from the first AP device, the first message including a first indication that the wireless node will switch from the first AP device to a second AP device also attached to the SMD entity. In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as reference 2110. Fig.23 as described.

[0224] The method 2100 then proceeds to step 2115, where after obtaining or outputting the second indication for transmission, the second AP device is communicated with via the second link during the handover. In some cases, the operation of this step involves or can be performed by circuits for communication and / or codes for communication, such as reference Fig.23 as described.

[0225] The method 2100 then proceeds to step 2120, disabling the first link with the first AP device after obtaining the third indication. In some cases, the operation of this step involves or can be performed by a circuit for disabling and / or a code for disabling, such as referring to Fig.23 as described.

[0226] In some aspects, the first message comprises a Roaming Notification Initiation (RAI) message.

[0227] In some aspects, the second indication and the third indication are received via a single message.

[0228] In some aspects, the method 2100 further includes obtaining a second message confirming the first indication before communicating with the second AP device via the second link. In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as referring to Fig.23 as described.

[0229] In some aspects, the method 2100 further includes obtaining one or more packets from the first AP device after obtaining the first message. In some cases, the operation of this step involves or can be performed by circuitry for obtaining and / or code for obtaining, such as referring to Fig.23 as described.

[0230] In some aspects, the method 2100 further includes obtaining a block acknowledgement (BA) request (BAR) from the first AP device. In some cases, the operation of this step involves or can be performed by circuitry for obtaining and / or code for obtaining, such as reference Fig.23 as described.

[0231] In some aspects, the method 2100 further includes outputting a BA for transmission in response to the BAR, the BA indicating one or more sequence numbers (SN) of the one or more packets. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0232] In some aspects, communicating with the second AP device via the second link occurs prior to disabling the first link.

[0233] In some aspects, the method 2100 further includes outputting one or more packets to the first AP device for transmission after obtaining the first message. In some cases, the operation of this step involves or can be performed by circuitry for outputting and / or code for outputting, such as referring to Fig.23 as described.

[0234] In some aspects, the first message also includes an indication of a deadline for completing the switch; and the deadline indicates a time when an attempt should be made to output the one or more packets for transmission.

[0235] In one aspect, method 2100 or any aspect related thereto may be performed by, for example, Fig.23 The method 2100 may be performed by an apparatus of a communication device 2300, including various components operable, configured or adapted to perform the method 2100. The communication device 2300 will be described in more detail below.

[0236] Notice, Fig.21This is merely one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with the present disclosure.

[0237] Fig. 22 It is shown that in Figure 1 and Figure 2 An example of a method 2200 of wireless communication at a first access point (AP) device of AP 110.

[0238] The method 2200 begins at step 2205, communicating with a wireless node attached to a single mobility domain (SMD) entity via a first link, the first AP device and the second AP device also both attached to the SMD entity. In some cases, the operation of this step involves or can be performed by a circuit for communication and / or a code for communication, such as reference Fig.23 as described.

[0239] The method 2200 then proceeds to step 2210, outputting a first message for transmission to the wireless node, the first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to the second AP device. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0240] The method 2200 then proceeds to step 2215, outputting the context information for transmission to the second AP device after sending the first message. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as referring to Fig.23 as described.

[0241] The method 2200 then proceeds to step 2220, outputting a second indication for the wireless node to enable a second link with the second AP device for transmission to the wireless node. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0242] In some aspects, the first message comprises a Roaming Notification Initiation (RAI) message.

[0243] In some aspects, the context information includes information about at least one of: an association context, a security context or traffic identifier (TID) to link mapping, one or more block acknowledgement (BA) sessions, a downlink packet buffer, an uplink packet reordering buffer, a sequence number (SN), or a packet number (PN).

[0244] In some aspects, the method 2200 further includes outputting a third indication for the wireless node to disable the first link with the first AP device for transmission to the wireless node. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0245] In some aspects, the second indication and the third indication are sent via a single message.

[0246] In some aspects, the second indication is output for transmission before the third indication is output for transmission.

[0247] In some aspects, the method 2200 further includes obtaining, from the wireless node, a second message confirming the first indication before outputting the second indication for transmission. In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as reference Fig.23 as described.

[0248] In some aspects, the method 2200 further includes outputting one or more packets to the wireless node for transmission after obtaining the first message. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0249] In some aspects, the method 2200 also includes outputting a block acknowledgement (BA) request (BAR) to the wireless node for transmission. In some cases, the operation of this step involves or can be performed by a circuit for outputting and / or a code for outputting, such as reference Fig.23 as described.

[0250] In some aspects, the method 2200 also includes obtaining a BA in response to the BAR, the BA indicating whether the wireless node has received one or more of the packets with the corresponding sequence number (SN). In some cases, the operation of this step involves or can be performed by a circuit for obtaining and / or a code for obtaining, such as reference Fig.23 as described.

[0251] In some aspects, the method 2200 further includes including the information from the BA in the context information output for transmission to the second AP device. In some cases, the operation of this step involves or can be performed by a circuit for including and / or a code for including, as described in reference to Fig.23 as described.

[0252] In some aspects, the first message also includes a fourth indication of a deadline for completing the handover; and the deadline indicates a time when an attempt should be made to output the one or more packets for transmission.

[0253] In one aspect, method 2200 or any aspect related thereto may be performed by, for example, Fig.23 The method 2200 may be performed by an apparatus of a communication device 2300, including various components operable, configured or adapted to perform the method 2200. The communication device 2300 will be described in more detail below.

[0254] Notice, Fig. 22 This is merely one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with the present disclosure.

[0255] Example Communication Device

[0256] Fig.23 Various aspects of an example communication device 2300 are depicted. In some aspects, the communication device 2300 is a station, such as described above with respect to Figure 1 and Figure 2 In some aspects, the communication device 2300 is an AP, such as the STA 120 described above. Figure 1 and Figure 2 Describe the AP 110.

[0257] The communication device 2300 includes a processing system 2305 coupled to a transceiver 2394 (e.g., a transmitter and / or a receiver). The transceiver 2394 is configured to transmit and receive signals for the communication device 2300, such as the various signals described herein, via an antenna 2396. The transceiver 2394 may be a reference Figure 2 Examples of aspects of the transceiver 222 and / or transceiver 254 are described. The processing system 2305 may be configured to perform processing functions for the communication device 2300, including processing signals received by and / or to be transmitted by the communication device 2300.

[0258] The processing system 2305 includes one or more processors 2310. In various aspects, the one or more processors 2310 may represent Figure 2 120 RX data processor 270, TX data processor 288, TX spatial processor 290 or controller 280. In various aspects, one or more processors 2310 may represent Figure 2One or more of the RX data processor 242, TX data processor 210, TX spatial processor 220, or controller 230 of the AP 110 shown in FIG. The one or more processors 2310 are coupled to the computer readable medium / memory 2360 via the bus 2392. In certain aspects, the computer readable medium / memory 2360 is configured to store instructions (e.g., computer executable code) that, when executed by the one or more processors 2310, cause the one or more processors 2310 to perform: Fig.16 Method 1600 described herein or any aspect thereof; Fig.17 Method 1700 described herein or any aspect thereof; and / or Fig.18 The method 1800 described herein or any aspect related thereto. Note that references to a processor performing functions of the communication device 2300 may include one or more processors 2310 performing functions of the communication device 2300.

[0259] In the depicted example, computer readable medium / memory 2360 stores codes (e.g., executable instructions) such as code for communicating 2365, code for enabling 2370, code for disabling 2375, code for adding 2380, code for removing 2382, code for obtaining 2384, code for identifying 2386, code for outputting 2388, and code for reordering 2390. Processing of code for communicating 2365, code for enabling 2370, code for disabling 2375, code for adding 2380, code for removing 2382, code for obtaining 2384, code for identifying 2386, code for outputting 2388, and code for reordering 2390 may cause communication device 2300 to perform: Fig.16 Method 1600 described herein or any aspect thereof; Fig.17 Method 1700 described herein or any aspect thereof; and / or Fig.18 The method 1800 described herein or any aspect related thereto.

[0260] The one or more processors 2310 include circuits configured to implement (e.g., execute) code stored in the computer-readable medium / memory 2360, including circuits such as circuits for communicating 2315, circuits for enabling 2320, circuits for disabling 2325, circuits for adding 2330, circuits for removing 2335, circuits for obtaining 2340, circuits for identifying 2345, circuits for outputting 2350, and circuits for reordering 2355. Processing using the circuits for communicating 2315, circuits for enabling 2320, circuits for disabling 2325, circuits for adding 2330, circuits for removing 2335, circuits for obtaining 2340, circuits for identifying 2345, circuits for outputting 2350, and circuits for reordering 2355 may cause the communication device 2300 to perform: Fig.16 Method 1600 described herein or any aspect thereof; Fig.17 Method 1700 described herein or any aspect thereof; and / or Fig.18 The method 1800 described herein or any aspect related thereto.

[0261] The various components of the communication device 2300 may provide means for performing the following operations: Fig.16 Method 1600 described herein or any aspect thereof; Fig.17 Method 1700 described herein or any aspect thereof; and / or Fig.18 For example, in some cases, a device for transmitting, sending, or outputting for transmission may include: Figure 2 The transceiver 254 or antenna 252 and / or Fig.23 The transceiver 2394 and antenna 2396 of the communication device 2300 in FIG. In some cases, a device for transmitting, sending, or outputting for transmission may include Figure 2 The transceiver 222 or antenna 224 and / or Fig.23 The transceiver 2394 and antenna 2396 of the communication device 2300 in FIG. In some aspects, the means for receiving or obtaining may include Figure 2 The transceiver 254 or antenna 252 and / or Fig.23 The transceiver 2394 and antenna 2396 of the communication device 2300 in FIG. In some aspects, the means for receiving or obtaining may include Figure 2 The transceiver 222 or antenna 224 and / or Fig.23The transceiver 2394 and antenna 2396 of the communication device 2300 in FIG. In some aspects, the means for communicating, the means for including, the means for enabling, the means for disabling, the means for adding, the means for removing, the means for obtaining, the means for identifying, the means for outputting, and / or the means for reordering may include one or more processors, such as those described above with reference to FIG. Figure 2 and / or one or more of the processors described in 23.

[0262] Sample Clauses

[0263] Examples of implementation are described in the following numbered clauses:

[0264] Clause 1: A method for wireless communication at a first wireless node, comprising: communicating with a first AP attached to an MLD via a first link; enabling a second link with a second AP device attached to the MLD; communicating with the first AP via the first link and communicating with the second AP device via the second link during a handover of the first wireless node from the first AP to the second AP device; and disabling the first link with the first AP after the handover is completed.

[0265] Clause 2: The method of clause 1, wherein when the second link is enabled, the second link is a member of an associated link set.

[0266] Clause 3: The method of clause 2, further comprising at least one of: adding a third link associated with a third AP affiliated with the MLD to the associated link set; or removing a fourth link associated with a fourth AP affiliated with the MLD from the associated link set.

[0267] Clause 4: The method of clause 3, further comprising: obtaining a beacon from the first AP; and identifying at least the second AP device and the third AP based on information in the beacon.

[0268] Clause 5: A method according to any of clauses 1-4, wherein, during switching, communicating with the first AP via the first link and communicating with the second AP device via the second link includes at least one of: obtaining a duplicate first packet through both the first link and the second link; or outputting a duplicate second packet for transmission via both the first link and the second link.

[0269] Clause 6: The method of any of clauses 1-5, further comprising: obtaining signaling from the first AP instructing the wireless node to enable the second link, wherein the wireless node enables the second link after obtaining the signaling.

[0270] Clause 7: The method of any of clauses 1-6, further comprising: outputting signaling to the first AP for transmission to initiate the handover, wherein the wireless node enables the second link after outputting the signaling.

[0271] Clause 8: The method of any of clauses 1-7, further comprising: obtaining signaling from a second AP device indicating that the wireless node is to disable the first link, wherein the wireless node disables the first link after obtaining the signaling.

[0272] Item 9: A method for wireless communication at a first AP device, comprising: communicating with a wireless node via a first link during a switching of the wireless node from the first AP device to a second AP device, wherein the wireless node is associated with an MLD, and both the first AP device and the second AP device are affiliated with the MLD; outputting context information of the MLD for transmission to the second AP device; and disabling the first link with the first wireless node after the switching.

[0273] Clause 10: The method of clause 9, wherein the context information of the MLD comprises information about at least one of: an association context, a security context or a TID to link mapping, one or more BA sessions, a downlink packet buffer, an uplink packet reordering buffer, a SN or a PN.

[0274] Clause 11: The method of any of clauses 9 and 10, further comprising: outputting a beacon identifying at least a second AP device for transmission.

[0275] Clause 12: A method according to any of clauses 9-11, wherein communicating with the wireless node during switching includes at least one of: outputting a copied first packet for transmission to the wireless node and a second AP device via the first link; or obtaining a copied second packet from the wireless node and the second AP device via the first link.

[0276] Clause 13: The method of clause 12, further comprising: reordering the copied second packets.

[0277] Clause 14: The method of any of clauses 9-13, further comprising: outputting signaling to the wireless node indicating that the wireless node is to disable the first link for communicating with the second AP device.

[0278] Clause 15: The method of any of clauses 9-14, further comprising: obtaining signaling from the wireless node to initiate a handover.

[0279] Clause 16: The method according to any one of clauses 9-15, further comprising: obtaining signaling indicating handover completion from the second AP device.

[0280] Clause 17: A method as described in any of clauses 9-16, wherein the context information of the MLD is output for transmission based on at least one of a timer or an uplink sequence number.

[0281] Clause 18: A method for wireless communication at a second AP device, comprising: communicating with a wireless node via a second link during a handover of the wireless node from a first AP device to a second AP device, wherein the wireless node is associated with an MLD to which both the first AP device and the second AP are attached; obtaining context information of the MLD from the first AP device; and outputting signaling indicating handover completion for transmission to the first AP device.

[0282] Clause 19: The method of clause 18, wherein the context information of the MLD comprises information about at least one of: an association context, a security context or a TID to link mapping, one or more BA sessions, a downlink packet buffer, an uplink packet reordering buffer, a SN, or a PN.

[0283] Clause 20: The method of any of clauses 18 and 19, further comprising: outputting a beacon identifying one or more neighboring APs of the second AP device for transmission.

[0284] Clause 21: A method according to any of clauses 18-20, wherein communicating with the wireless node during switching includes at least one of: outputting a replicated packet for transmission to the wireless node and the first AP device via the second link; or obtaining a replicated packet from the wireless node and from the first AP device via the second link.

[0285] Clause 22: The method of clause 21, further comprising: outputting the duplicated packets to a first AP device for reordering for transmission.

[0286] Clause 23: The method of any of clauses 18-22, further comprising: outputting signaling indicating handover completion to the first AP device for transmission.

[0287] Clause 24: The method of any of clauses 18-23, further comprising: outputting signaling for a gateway to switch a data path from the first AP device to the second AP device for transmission.

[0288] Clause 25: An apparatus comprising: a memory including executable instructions; and a processor configured to execute the executable instructions and cause the apparatus to perform the method according to any of clauses 1-24.

[0289] Clause 26: An apparatus comprising means for performing the method according to any of clauses 1-24.

[0290] Clause 27: A non-transitory computer-readable medium comprising executable instructions, which, when executed by a processor of an apparatus, cause the apparatus to perform the method according to any one of clauses 1-24.

[0291] Clause 28: A computer program product embodied on a computer readable storage medium, comprising code for performing the method according to any of clauses 1-24.

[0292] Clause 29: A first wireless station comprising: at least one transceiver; a memory comprising instructions; and one or more processors configured to execute the instructions and cause the wireless node to perform a method according to any one of clauses 1-8, wherein the at least one transceiver is configured to transmit a waveform.

[0293] Clause 30: A first AP device comprising: at least one transceiver; a memory comprising instructions; and one or more processors configured to execute the instructions and cause a wireless node to perform a method according to any one of clauses 9-17, wherein at least one transceiver is configured to transmit a waveform.

[0294] Clause 31: A second AP device comprising: at least one transceiver; a memory comprising instructions; and one or more processors configured to execute the instructions and cause a wireless node to perform a method according to any of clauses 18-23, wherein at least one transceiver is configured to transmit a waveform.

[0295] Clause 32: A method for wireless communication at a wireless node, comprising: communicating with a first access point (AP) device attached to a single mobility domain (SMD) entity via a first link; outputting a first message for transmission to the first AP device, the first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to a second AP device attached to the SMD entity; after obtaining a second indication that context information has been transmitted from the first AP device to the second AP device, communicating with the second AP device via a second link during the handover; and after obtaining a third indication that triggers the wireless node to disable the first link with the first AP device, disabling the first link with the first AP device.

[0296] Clause 33: The method of clause 32, wherein the first message comprises a Roaming Notification Initiation (RAI) message.

[0297] Clause 34: The method of any of clauses 32-33, wherein the second indication and the third indication are received via a single message.

[0298] Clause 35: A method as described in any of clauses 32-34, wherein the first message further comprises a fourth indication of a deadline for completing the handover.

[0299] Clause 36: The method of any of clauses 32-35, further comprising: obtaining a second message via the first link before communicating with the second AP device, wherein the second message confirms the first indication.

[0300] Clause 37: The method of any of clauses 32-36, further comprising: obtaining one or more packets from the first AP device after outputting the first message for transmission.

[0301] Clause 38: The method of clause 37, further comprising: obtaining a block acknowledgement (BA) request (BAR) from the first AP device; and outputting a BA for transmission in response to the BAR, the BA indicating a sequence number (SN) of one or more packets.

[0302] Clause 39: The method of any of clauses 32-38, wherein communicating with the second AP device via the second link occurs before disabling the first link.

[0303] Item 40: A method for wireless communication at a first access point (AP) device, comprising: communicating with a wireless node attached to a single mobility domain (SMD) entity via a first link, the first AP device and the second AP device also both attached to the SMD entity; obtaining a first message from the wireless node, the first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to the second AP device; after obtaining the first message, outputting context information for transmission to the second AP device; outputting a second indication that triggers the wireless node to enable a second link with the second AP device for transmission to the wireless node; and outputting a third indication that triggers the wireless node to disable the first link with the first AP device for transmission to the wireless node.

[0304] Clause 41: The method of clause 40, wherein the first message comprises a Roaming Notification Initiation (RAI) message.

[0305] Clause 42: A method according to any of clauses 40-41, wherein the context information includes information about at least one of: an association context, a security context or a traffic identifier (TID) to link mapping, one or more block acknowledgment (BA) sessions, a downlink packet buffer, an uplink packet reordering buffer, a sequence number (SN) or a packet number (PN).

[0306] Clause 43: The method of any of clauses 40-42, wherein the second indication and the third indication are sent via a single message.

[0307] Clause 44: The method of any of clauses 40-43, further comprising: prior to sending the first indication, outputting a second message confirming the first indication for transmission to the wireless node.

[0308] Clause 45: The method of any of clauses 40-44, further comprising, after obtaining the first message, outputting one or more packets from the queue to the wireless node to be dequeued for transmission before the handover is completed.

[0309] Clause 46: The method according to any one of clauses 40-45 further includes: outputting a block acknowledgment (BA) request (BAR) to a wireless node for transmission; obtaining a BA in response to the BAR, the BA indicating whether the wireless node has received one or more packets with corresponding one or more sequence numbers (SN); and including information from the BA in context information output for transmission to a second AP device.

[0310] Clause 47: A method according to any of clauses 40-46, wherein at least one of the following: the first message also includes an indication of a deadline for completing the switch; and the deadline indicates a time when the first AP device attempts to send one or more packets from the queue to the wireless node; or the queue is empty before the switch is completed.

[0311] Clause 48: A method according to any of clauses 40-47, wherein the second indication is output for transmission before the third indication is output for transmission.

[0312] Clause 49: A method for wireless communication at a wireless node, comprising: communicating with a first access point (AP) device attached to a single mobility domain (SMD) entity via a first link; obtaining a first message from the first AP device, the first message including a first indication that the wireless node will switch from the first AP device to a second AP device also attached to the SMD entity; after obtaining or outputting a second indication for transmission, communicating with the second AP device via a second link during the switching; and disabling the first link with the first AP device after obtaining a third indication.

[0313] Clause 50: The method of clause 49, wherein the first message comprises a Roaming Notification Initiation (RAI) message.

[0314] Clause 51: The method of any of clauses 49-50, wherein the second indication and the third indication are received via a single message.

[0315] Clause 52: The method of any of clauses 49-51, further comprising: obtaining a second message confirming the first indication before communicating with the second AP device via the second link.

[0316] Clause 53: The method of any of clauses 49-52, further comprising: after obtaining the first message, obtaining one or more packets from the first AP device.

[0317] Clause 54: The method according to clause 53 further includes: obtaining a block acknowledgement (BA) request (BAR) from the first AP device; and outputting a BA for transmission in response to the BAR, the BA indicating one or more sequence numbers (SN) of one or more packets.

[0318] Clause 55: The method of any of clauses 49-54, wherein communicating with the second AP device via the second link occurs before disabling the first link.

[0319] Clause 56: The method of any of clauses 49-55, further comprising: after obtaining the first message, outputting one or more packets to the first AP device for transmission.

[0320] Clause 57: The method of clause 56, wherein: the first message further includes an indication of a deadline for completing the handover; and the deadline indicates a time when an attempt should be made to output the one or more packets for transmission.

[0321] Item 58: A method for wireless communication at a first access point (AP) device, comprising: communicating with a wireless node attached to a single mobility domain (SMD) entity via a first link, the first AP device and the second AP device also both attached to the SMD entity; outputting a first message for transmission to the wireless node, the first message including a first indication that the wireless node is initiating a switching of the wireless node from the first AP device to the second AP device; after sending the first message, outputting context information for transmission to the second AP device; and outputting a second indication for the wireless node to enable a second link with the second AP device for transmission to the wireless node.

[0322] Clause 59: The method of clause 58, wherein the first message comprises a Roaming Notification Initiation (RAI) message.

[0323] Clause 60: A method according to any of clauses 58-59, wherein the context information includes information about at least one of: an association context, a security context or a traffic identifier (TID) to link mapping, one or more block acknowledgment (BA) sessions, a downlink packet buffer, an uplink packet reordering buffer, a sequence number (SN) or a packet number (PN).

[0324] Clause 61: The method of any one of clauses 58-60, further comprising: outputting a third indication for transmission to the wireless node, the third indication being used by the wireless node to disable the first link with the first AP device.

[0325] Clause 62: The method of clause 61, wherein the second indication and the third indication are sent via a single message.

[0326] Clause 63: The method of clause 61, wherein the second indication is output for transmission before the third indication is output for transmission.

[0327] Clause 64: The method of any of clauses 58-63, further comprising: obtaining, from the wireless node, a second message confirming the first indication before outputting the second indication for transmission.

[0328] Clause 65: The method of any of clauses 58-64, further comprising: after obtaining the first message, outputting one or more packets to the wireless node for transmission.

[0329] Clause 66: The method according to clause 65 further includes: outputting a block acknowledgment (BA) request (BAR) to a wireless node for transmission; obtaining a BA in response to the BAR, the BA indicating whether the wireless node has received one or more packets with a corresponding sequence number (SN); and including information from the BA in context information output for transmission to a second AP device.

[0330] Clause 67: The method of clause 65, wherein: the first message further comprises a fourth indication of a deadline for completing the handover; and the deadline indicates a time when an attempt should be made to output the one or more packets for transmission.

[0331] Clause 68: The method of any of clauses 1-67, wherein the first AP device and the second AP device are non-collocated.

[0332] Clause 69: An apparatus comprising: a memory including executable instructions; and a processor configured to execute the executable instructions and cause the apparatus to perform the method of any of clauses 1-67.

[0333] Clause 70: An apparatus comprising means for performing the method of any of clauses 1-67.

[0334] Clause 71: A non-transitory computer-readable medium comprising executable instructions that, when executed by a processor of an apparatus, cause the apparatus to perform the method of any of clauses 1-67.

[0335] Clause 72: A computer program product embodied on a computer readable storage medium, comprising code for performing the method according to any of clauses 1-67.

[0336] Clause 73: A wireless node comprising: at least one transceiver; a memory comprising instructions; and one or more processors configured to execute the instructions and cause the wireless node to perform a method according to any of clauses 32-39, wherein the at least one transceiver is configured to send a first message.

[0337] Clause 74: A first AP device comprising: at least one transceiver; a memory comprising instructions; and one or more processors configured to execute the instructions and cause a wireless node to perform a method according to any one of clauses 40-48, wherein at least one transceiver is configured to receive a first message and send context information.

[0338] Clause 75: A wireless node comprising: at least one transceiver; a memory comprising instructions; and one or more processors configured to execute the instructions and cause the wireless node to perform a method according to any of clauses 49-57, wherein the at least one transceiver is configured to receive a first message.

[0339] Clause 76: A first AP device comprising: at least one transceiver; a memory comprising instructions; and one or more processors configured to execute the instructions and cause a wireless node to perform a method according to any of clauses 58-67, wherein at least one transceiver is configured to send a first message and send context information.

[0340] Other considerations

[0341] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples discussed herein do not limit the scope, applicability or aspects set forth in the claims. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. For example, without departing from the scope of the present disclosure, the functions and arrangements of the elements discussed may be changed. Various examples may appropriately omit, replace or add various processes or components. For example, the described methods may be performed in a different order than described, and various actions may be added, omitted or combined. In addition, the features described with respect to some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such devices or methods, which are practiced using other structures, functions or structures and functions on or in addition to the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein may be embodied by one or more elements of a claim.

[0342] The various illustrative logical blocks, modules, and circuits described in conjunction with the present disclosure may be implemented or performed using a general purpose processor, a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, a system on a chip (SoC), or any other such configuration.

[0343] As used herein, "processor," "at least one processor," or "one or more processors" generally refers to a single processor configured to perform one or more operations or multiple processors configured to perform one or more operations together. In the case of multiple processors, the execution of one or more operations may be divided between different processors, although a processor may perform multiple operations and multiple processors may perform a single operation together. Similarly, "memory," "at least one memory," or "one or more memories" generally refers to a single memory configured to store data and / or instructions, multiple memories configured to store data and / or instructions together.

[0344] As used herein, a phrase referring to "at least one" of a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other ordering of a, b, and c).

[0345] As used herein, the term "determining" includes a variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or other data structure), ascertaining, etc. In addition, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. In addition, "determining" may include solving, selecting, choosing, establishing, etc.

[0346] The methods disclosed herein include one or more actions for implementing these methods. Without departing from the scope of the claims, the method actions can be interchangeable with each other. In other words, unless a specific sequence of actions is specified, the order and / or use of specific actions can be modified without departing from the scope of the claims. In addition, the various operations of the above methods can be performed by any suitable device capable of performing the corresponding functions. The device may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs) or processors.

[0347] The following claims are not intended to be limited to the aspects shown herein, but should be given the full scope consistent with the language of the claims. In the claims, unless otherwise specified, the elements mentioned in the singular form do not mean "one and only one", but "one or more". Unless otherwise specifically stated, the term "some" refers to one or more. No claim element shall be interpreted according to the provisions of Section 112 (f) of Title 35 of the United States Code unless the element is explicitly stated using the phrase "device for...". All structural and functional equivalents of the elements throughout the various aspects described in this disclosure that are known or will be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly listed in the claims.

Claims

1. A device for wireless communication, comprising: One or more processors, individually or collectively configured to execute instructions stored on one or more memories and cause the apparatus to: communicating with a first access point AP device attached to a single mobility domain SMD entity via a first link; Outputting a first message for transmission to the first AP device, the first message including a first indication that the apparatus is initiating a handover of the apparatus from the first AP device to a second AP device attached to the SMD entity; after obtaining a second indication that context information has been transmitted from the first AP device to the second AP device, communicating with the second AP device via a second link during the handover; as well as After obtaining a third indication triggering the apparatus to disable the first link with the first AP device, the first link with the first AP device is disabled.

2. The device according to claim 1, wherein: The first message comprises a Roaming Notification Initiation (RAI) message.

3. The device according to claim 1, wherein: receiving the second indication and the third indication via a single message; or The first message also includes a fourth indication of a deadline for completing the handover.

4. The device according to claim 1, wherein: The one or more processors are further configured to execute computer-executable instructions and cause the apparatus to obtain a second message via the first link before communicating with the second AP device, wherein the second message confirms the first indication.

5. The device according to claim 1, wherein: The one or more processors are further configured to execute computer-executable instructions and cause the apparatus to obtain one or more packets from the first AP device after outputting the first message for transmission.

6. The device according to claim 5, wherein: The one or more processors are further configured to execute computer executable instructions and cause the apparatus to: Obtain a block acknowledgement request (BA) from the first AP device; and In response to the BAR, a BA is output for transmission, the BA indicating a sequence number (SN) of the one or more packets.

7. The device according to claim 1, wherein: Communicating with the second AP device via a second link occurs prior to disabling the first link.

8. The apparatus of claim 1, further comprising at least one transceiver configured to send the first message, wherein: The apparatus is configured as a wireless station.

9. An apparatus for wireless communication, comprising: One or more processors, individually or collectively configured to execute instructions stored on one or more memories and cause the apparatus to: communicating with a wireless node attached to a single mobile domain SMD entity via the first link, the first access point AP device and the second AP device also both being attached to the SMD entity; obtaining a first message from the wireless node, the first message including a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to the second AP device; After obtaining the first message, outputting context information for transmission to the second AP device; Outputting a second indication for triggering the wireless node to enable a second link with the second AP device for transmission to the wireless node; as well as A third indication is output for transmission to the wireless node, triggering the wireless node to disable the first link with the first AP device.

10. The device according to claim 9, wherein: The first message comprises a Roaming Notification Initiation (RAI) message.

11. The device according to claim 9, wherein: The context information includes information about at least one of: an association context, a security context, or a traffic identifier (TID) to link mapping, one or more block acknowledgement (BA) sessions, a downlink packet buffer, an uplink packet reordering buffer, a sequence number (SN), or a packet number (PN).

12. The device according to claim 9, wherein: The second indication and the third indication are sent via a single message.

13. The device according to claim 9, wherein: The one or more processors are further configured to execute computer executable instructions and cause the apparatus to output at least one of the following for transmission to the wireless node: a second message confirming the first indication before sending the first indication; or After obtaining the first message, one or more packets are output from a queue to the wireless node to drain the queue before the handover is completed.

14. The device according to claim 9, wherein: The one or more processors are further configured to execute computer executable instructions and cause the apparatus to: Outputting a block acknowledgement request (BA) to the wireless node for transmission; obtaining a BA in response to the BAR, the BA indicating whether the wireless node received one or more packets having corresponding one or more sequence numbers (SNs); as well as Information from the BA is included in the context information that is output for transmission to the second AP device.

15. The device according to claim 9, wherein: At least one of the following: The first message also includes an indication of a deadline for completing the handover; The deadline indicates a time when the first AP device attempts to send one or more packets from a queue to the wireless node; or The queue is empty before the handover is completed.

16. The device according to claim 9, wherein: Before outputting the third indication for transmission, the second indication is output for transmission.

17. The apparatus of claim 9, further comprising at least one transceiver configured to receive the first message, wherein: The apparatus is configured as the first AP device.

18. An apparatus for wireless communication, comprising: One or more processors, individually or collectively configured to execute instructions stored on one or more memories and cause the apparatus to: communicating with a first access point AP device attached to a single mobility domain SMD entity via a first link; obtaining a first message from the first AP device, the first message including a first indication that the apparatus is to switch from the first AP device to a second AP device also attached to the SMD entity; After obtaining or outputting a second indication for transmission, communicating with the second AP device via a second link during the handover; as well as The first link with the first AP device is disabled after obtaining a third indication.

19. The device according to claim 18, wherein: The first message comprises a Roaming Notification Initiation (RAI) message.

20. The device according to claim 18, wherein The second indication and the third indication are received via a single message.

21. The device according to claim 18, wherein The one or more processors are further configured to execute computer executable instructions and cause the apparatus to obtain at least one of the following: Before communicating with the second AP device via the second link, obtaining a second message confirming the first indication; or After obtaining the first message, one or more packets are obtained from the first AP device.

22. The device according to claim 21, wherein The one or more processors are further configured to execute computer executable instructions and cause the apparatus to: Obtain a block acknowledgement request (BA) from the first AP device; and In response to the BAR, a BA is output for transmission, the BA indicating one or more sequence numbers (SN) of the one or more packets.

23. The device according to claim 18, wherein Before disabling the first link, communicating with the second AP device via the second link.

24. The device according to claim 18, wherein: The one or more processors are further configured to execute computer-executable instructions and cause the apparatus to: after obtaining the first message, output one or more packets to the first AP device for transmission.

25. The apparatus of claim 24, wherein: The first message also includes an indication of a deadline for completing the handover; and The deadline indicates a time when an attempt should be made to output the one or more packets for transmission.

26. The apparatus of claim 18, further comprising at least one transceiver configured to receive the first message, wherein: The apparatus is configured as a wireless station.

27. An apparatus for wireless communication, comprising: One or more processors, individually or collectively configured to execute instructions stored on one or more memories and cause the apparatus to: Communicating, via a first link, with a wireless node attached to a single mobile domain SMD entity, to which both the first AP device and the second AP device are also attached; outputting a first message for transmission to the wireless node, the first message comprising a first indication that the wireless node is initiating a handover of the wireless node from the first AP device to the second AP device; After sending the first message, outputting context information for transmission to the second AP device; as well as A second indication for enabling a second link with the second AP device is output for transmission to the wireless node.

28. The device according to claim 27, wherein The first message comprises a Roaming Notification Initiation (RAI) message.

29. The device according to claim 27, wherein: The context information includes information about at least one of: an association context, a security context, or a traffic identifier (TID) to link mapping, one or more block acknowledgement (BA) sessions, a downlink packet buffer, an uplink packet reordering buffer, a sequence number (SN), or a packet number (PN).

30. The device according to claim 27, wherein: The one or more processors are further configured to execute computer-executable instructions and cause the apparatus to: output a third indication for the wireless node to disable the first link with the first AP device for transmission to the wireless node.

31. The device according to claim 30, wherein The second indication and the third indication are sent via a single message.

32. The device according to claim 30, wherein: Before outputting the third indication for transmission, the second indication is output for transmission.

33. The apparatus of claim 27, wherein: The one or more processors are further configured to execute computer executable instructions and cause the apparatus to perform at least one of the following: Before outputting the second indication for transmission, obtaining from the wireless node a second message confirming the first indication; or After obtaining the first message, one or more packets are output to the wireless node for transmission.

34. The device according to claim 33, wherein: The one or more processors are further configured to execute computer executable instructions and cause the apparatus to: Outputting a block acknowledgement request (BA) to the wireless node for transmission; obtaining a BA in response to the BAR, the BA indicating whether the wireless node received one or more packets having a corresponding sequence number (SN); as well as Information from the BA is included in the context information that is output for transmission to the second AP device.

35. The apparatus of claim 33, wherein: The first message also includes a fourth indication of a deadline for completing the switching; and The deadline indicates when an attempt should be made to output one or more packets for transmission.

36. The apparatus of claim 27, further comprising at least one transceiver configured to transmit the first message, wherein The apparatus is configured as the first AP device.

37. An apparatus for wireless communication, comprising: One or more processors, individually or collectively configured to execute instructions stored on one or more memories and cause the apparatus to: communicating with a first access point AP attached to a multi-link device MLD via a first link; enabling a second link with a second AP affiliated with the MLD; During a handover of a first wireless station from the first AP to the second AP, communicating with the first AP via the first link and communicating with the second AP via the second link; as well as The first link with the first AP is disabled after the switching is completed.

38. The device according to claim 37, wherein When the second link is enabled, the second link is a member of an associated link set.

39. The device according to claim 38, wherein The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to perform at least one of the following: adding a third link associated with a third AP affiliated with the MLD to the associated link set; or A fourth link associated with a fourth AP affiliated with the MLD is removed from the set of associated links.

40. The device according to claim 39, wherein The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: Obtaining a beacon from the first AP; as well as At least the second AP and the third AP are identified based on information in the beacon.

41. The apparatus of claim 37, wherein: During the handover, communicating with the first AP via the first link and communicating with the second AP via the second link includes at least one of: obtaining a duplicate first packet via both the first link and the second link; or The duplicate second packet is output for transmission via both the first link and the second link.

42. The apparatus of claim 37, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: The wireless station obtains signaling from the first AP instructing the wireless station to enable the second link, wherein the wireless station enables the second link after obtaining the signaling.

43. The apparatus of claim 37, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: The wireless station outputs a signaling for initiating the switching to the first AP for transmission, wherein the wireless station enables the second link after outputting the signaling.

44. The apparatus of claim 37, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: Obtain signaling from the second AP indicating that the wireless station is to disable the first link, wherein the wireless station disables the first link after obtaining the signaling.

45. The apparatus of claim 37, further comprising at least one transceiver, wherein: The at least one transceiver is configured to communicate with the first AP via the first link, and the apparatus is configured as a wireless station.

46. ​​An apparatus for wireless communication, comprising: One or more processors, individually or collectively configured to execute instructions stored on one or more memories and cause the apparatus to: communicating with the wireless station via a first link during a handover of the wireless station from the apparatus to a second AP, wherein the wireless station is associated with a multi-link device MLD to which both the apparatus and the second AP are attached; outputting the context information of the MLD for transmission to the second AP; and The first link with the first wireless station is disabled after the switching.

47. The device according to claim 46, wherein The context information of the MLD includes information about at least one of: association context, security context, or TID to link mapping, one or more BA sessions, downlink packet buffer, uplink packet reordering buffer, sequence number (SN) or packet number (PN).

48. The apparatus of claim 46, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: A beacon identifying at least the second AP is output for transmission.

49. The apparatus of claim 46, wherein: Communicating with the wireless station during the handover includes at least one of: outputting a duplicate first packet for transmission both to the second AP and to the wireless station via the first link; or A duplicate second packet is obtained both from the second AP and from the wireless station via the first link.

50. The apparatus of claim 49, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: reorder the copied second packets.

51. The apparatus of claim 46, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: Signaling is output to the wireless station indicating that the wireless station is to disable the first link for communicating with the second AP.

52. The apparatus of claim 46, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: Signaling to initiate the handover is obtained from the wireless station.

53. The apparatus of claim 46, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: A signaling indicating completion of the handover is obtained from the second AP.

54. The apparatus of claim 46, wherein: The context information of the MLD is output for transmission based on at least one of a timer or an uplink sequence number.

55. The apparatus of claim 46, further comprising at least one transceiver, wherein: The at least one transceiver is configured to send context information of the MLD to the second AP, and the apparatus is configured as a first AP.

56. An apparatus for wireless communication, comprising: One or more processors, individually or collectively configured to execute instructions stored on one or more memories and cause the apparatus to: communicating with the wireless station via a second link during a handover of the wireless station from a first AP device to the apparatus, wherein the wireless station is associated with a multi-link device MLD, the first AP and the apparatus both being attached to the MLD; Obtaining context information of the MLD from the first AP; and Output signaling indicating that the switching is completed for transmission to the first AP.

57. The apparatus of claim 56, wherein: The context information of the MLD includes information about at least one of: association context, security context, or TID to link mapping, one or more BA sessions, downlink packet buffer, uplink packet reordering buffer, sequence number (SN) or packet number (PN).

58. The apparatus of claim 56, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: A beacon identifying one or more neighboring APs of the apparatus is output for transmission.

59. The apparatus of claim 56, wherein: Communicating with the wireless station during the handover includes at least one of: outputting the duplicated packet for transmission both to the first AP and to the wireless station via the second link; or The copied packets are obtained both from the first AP and from the wireless station via the second link.

60. The apparatus of claim 59, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: output the duplicated packet to the first AP for reordering.

61. The apparatus of claim 56, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: Signaling indicating completion of the handover is output to the first AP for transmission.

62. The apparatus of claim 56, wherein: The one or more processors are further configured to execute processor-executable instructions and cause the apparatus to: Outputting signaling for a gateway to switch a data path from the first AP to the device for transmission.

63. The apparatus of claim 56, further comprising at least one transceiver, wherein: The at least one transceiver is configured to receive the context information from the first AP, and the apparatus is configured as a second AP.

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