Context acquisition for seamless roaming

Abstract

The invention provides a method, a component, equipment and a system for supporting context acquisition for seamless roaming. Some aspects are more particularly directed to spatially segmenting packet numbers (PNs) into subsets that are dynamically assigned to access points (APs) associated with stations (STAs). In some implementations, a first wireless device, such as an STA, may communicate with a second wireless device, such as a serving AP, using a first subset of user data context parameters, such as a group or segment of PNs, corresponding to a first index assigned to the second wireless device. For example, if the first wireless device decides to roam to a third wireless device, such as a target AP, the first wireless device may transmit one or more packets to the third wireless device using a second subset of user data context parameters assigned to the third wireless device.

Description

[0001] Cross-references

[0002] This patent application claims the benefit of U.S. Patent Application No. 18 / 464,193, filed September 8, 2023, entitled “CONTEXT ACQUISITIONFOR SEAMLESS ROAMING”, which has been assigned to the assignee of this application and is expressly incorporated herein by reference. Technical Field

[0003] This disclosure relates to wireless communications, and more specifically to context acquisition for seamless roaming. Background Technology

[0004] A Wireless Local Area Network (WLAN) can be formed by one or more wireless access points (APs) that provide a shared wireless communication medium for use by multiple client devices (also known as wireless stations (STAs)). The basic building block of a WLAN conforming to the IEEE 802.11 standard family is the Basic Service Set (BSS) managed by the AP. Each BSS is identified by a Basic Service Set Identifier (BSSID) advertised by the AP. The AP periodically broadcasts beacon frames to enable any STA within the AP's wireless range to establish or maintain a communication link with the WLAN.

[0005] In some WLANs, a STA can roam from one AP (such as the serving AP) to another AP (such as the target AP) based on various conditions, including (but not limited to) the STA's location or the target AP's signal strength. However, in some implementations, the STA may be unable to exchange data with the target AP until it obtains contextual information (such as a set of encryption keys) from the target AP, which can increase the latency associated with roaming operations. Summary of the Invention

[0006] The systems, methods, and apparatus disclosed herein each have some innovative aspects, and no single aspect is solely responsible for the desired properties disclosed herein.

[0007] A first wireless device is described. The first wireless device includes a processing system comprising processor circuitry and memory circuitry storing code, wherein the processing system is configured to cause the first wireless device to: communicate with a second wireless device via a first set of communication links between the first and second wireless devices using a first subset of user data context parameters corresponding to a first index assigned to the second wireless device; roam from the second wireless device to the third wireless device based on the state of the first set of communication links and based on the state of a second set of communication links between the first and third wireless devices, wherein the roaming includes transmitting user data to the third wireless device via the second set of communication links using a second subset of the user data context parameters corresponding to a second index assigned to the third wireless device; and communicate with the third wireless device via the second set of communication links based on roaming from the second wireless device to the third wireless device using the second subset of the user data context parameters.

[0008] A third wireless device is described. The third wireless device includes a processing system comprising processor circuitry and memory circuitry storing code, wherein the processing system is configured to cause the third wireless device to: obtain an indication of a second index assigned to the third wireless device, the second index corresponding to a second subset of user data context parameters usable for communication with a first wireless device; receive user data via a second set of communication links between the third wireless device and a first wireless device roaming from the second wireless device to the third wireless device, the user data indicating the second subset of user data context parameters corresponding to the second index assigned to the third wireless device, wherein a first subset of the user data context parameters corresponds to a first index assigned to the first wireless device from which it is roaming; and, based on the user data received from the first wireless device roaming from the second wireless device to the third wireless device, communicate with the first wireless device via the second set of communication links using the second subset of user data context parameters corresponding to the second index assigned to the third wireless device.

[0009] A method for wireless communication by a first wireless device is described. The method includes: communicating with a second wireless device via a first set of communication links between the first and second wireless devices using a first subset of user data context parameters corresponding to a first index assigned to the second wireless device; roaming from the second wireless device to the third wireless device based on the state of the first set of communication links and the state of a second set of communication links between the first and third wireless devices, wherein the roaming includes transmitting user data to the third wireless device via the second set of communication links using a second subset of the user data context parameters corresponding to a second index assigned to the third wireless device; and communicating with the third wireless device via the second set of communication links based on roaming from the second wireless device to the third wireless device using the second subset of the user data context parameters.

[0010] A method for wireless communication by a third wireless device is described. The method includes: obtaining an indication of a second index assigned to the third wireless device, the second index corresponding to a second subset of user data context parameters usable for communication with a first wireless device; receiving user data via a second set of communication links between the third wireless device and a first wireless device roaming from the second wireless device to the third wireless device, the user data indicating the second subset of user data context parameters corresponding to the second index assigned to the third wireless device, wherein a first subset of the user data context parameters corresponds to a first index assigned to the first wireless device from which it is roaming; and, based on the user data received from the first wireless device roaming from the second wireless device to the third wireless device, communicating with the first wireless device via the second set of communication links using the second subset of user data context parameters corresponding to the second index assigned to the third wireless device.

[0011] In some specific implementations, the first wireless device may send or receive a message containing a packet number (PN) field associated with a second index assigned to a third wireless device via a second set of communication links, wherein a first number of bits in the PN field indicates the second index, and a second number of bits in the PN field indicates the PN value within the PN segment associated with the second index.

[0012] In some other specific implementations, the first wireless device may send or receive frames via a second set of communication links containing a PN value associated with a second subset of user data context parameters and a separate field indicating a second index assigned to a third wireless device.

[0013] Details of one or more specific embodiments of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. Note that the relative dimensions in the following drawings are not to scale. Attached Figure Description

[0014] Figure 1 A schematic diagram of an example wireless communication network is shown.

[0015] Figure 2 An example Protocol Data Unit (PDU) is shown that can be used for communication between a wireless access point (AP) and one or more wireless stations (STA).

[0016] Figure 3 An example physical layer (PHY) protocol data unit (PPDU) capable of being used for communication between a wireless AP and one or more wireless STAs is shown.

[0017] Figure 4 A hierarchical format of an example PPDU that can be used for communication between a wireless AP and one or more wireless STAs is shown.

[0018] Figure 5 An example of a signaling graph supporting context acquisition for seamless roaming is shown.

[0019] Figure 6 An example of the process flow that supports context fetching for seamless roaming is shown.

[0020] Figure 7 A block diagram of an example wireless device that supports context acquisition for seamless roaming is shown.

[0021] Figure 8 A block diagram of an example wireless device that supports context acquisition for seamless roaming is shown.

[0022] Figure 9 A flowchart illustrating an example process for context acquisition supporting seamless roaming, which can be performed by or at a first wireless device, is shown.

[0023] Figure 10 A flowchart illustrating an example process for context acquisition supporting seamless roaming, which can be performed by or at a third wireless device.

[0024] The same reference numerals and names in different figures denote the same elements. Detailed Implementation

[0025] The following description refers to certain specific examples in order to illustrate the innovative aspects of this disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in a variety of different ways. Some or all of the examples described can be applied in Bluetooth systems that meet the requirements of the Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.15, or Bluetooth as defined by the Bluetooth Special Interest Group (SIG). ® It is implemented in any device, system, or network that transmits and receives radio frequency (RF) signals, such as standards or those published by the 3rd Generation Partnership Project (3GPP) for Long Term Evolution (LTE), 3G, 4G, or 5G (New Radio (NR)).

[0026] The described examples can be implemented in any device, system, or network capable of transmitting and receiving RF signals according to one or more of the following technologies or techniques: Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiplexing (OFDM), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Space Division Multiple Access (SDMA), Rate Split Multiple Access (RSMA), Multi-User Shared Access (MUSA), Single-User (SU) Multiple-Input Multiple-Output (MIMO), and Multi-User (MU) MIMO (MU-MIMO). The described examples can also be implemented using other wireless communication protocols or RF signals suitable for use in one or more of the following networks: Wireless Personal Area Network (WPAN), Wireless Local Area Network (WLAN), Wireless Wide Area Network (WWAN), Wireless Metropolitan Area Network (WMAN), or Internet of Things (IoT) networks.

[0027] A WLAN may include one or more access points (APs) and non-AP stations (STAs) that communicate with each other via specific communication links, such as channels within a given frequency band. In some WLANs that support multi-link operation (MLO), a non-AP STA may be attached to a non-AP multi-link device (MLD) that operates on multiple communication links. For example, the first STA of a non-AP MLD may operate on a first communication link (such as a 2.4 GHz channel), while the second STA of a non-AP MLD may operate on a second communication link (such as a 6 GHz channel). Similarly, an AP may be attached to (e.g., controlled or managed by) one or more AP MLDs that operate on more than one communication link. As used herein, the term “STA” can refer to any type of wireless STA, such as a non-AP STA, a non-MLD STA, a non-MLD non-AP STA, etc. Similarly, the term “AP” can refer to any type of wireless AP, such as an APMLD or a non-MLD AP, etc.

[0028] In some implementations, a STA (such as a non-AP MLD or a non-MLD non-AP STA) can roam from a first AP (such as the serving AP) to a second AP (such as the target AP) based on various conditions, including (but not limited to) the STA's location, the signal strength of the first AP, and the signal strength of the second AP. However, in order to begin exchanging user data with the second AP, the STA may have to wait for the first AP to provide the second AP with various user data context parameters, such as encryption keys, packet numbers (PN), sequence numbers (SN), block acknowledgments (BA), and the set of encryption keys for the STA, which can introduce latency and signaling overhead.

[0029] Various aspects of this disclosure generally relate to context acquisition for seamless roaming. Some aspects more specifically relate to segmenting a PN space into subsets dynamically assigned to APs associated with a given STA. In some specific implementations, a first wireless device (such as a non-AP MLD or a non-MLD non-AP STA) can communicate with the second wireless device using a first subset of user data context parameters (such as groups or segments of the PN) corresponding to a first index assigned to a second wireless device (such as the serving AP of the first wireless device). For example, if the first wireless device decides to roam to a third wireless device (such as a target or neighboring AP), the first wireless device can use a second subset of the user data context parameters assigned to the third wireless device to send one or more packets to the third wireless device, thereby enabling the first wireless device to begin exchanging user data with the third wireless device without waiting for the second wireless device to provide user data context information to the third wireless device.

[0030] Specific aspects of the subject matter described in this disclosure can be implemented to achieve one or more of the following potential advantages. In some specific implementations, the described techniques enable a STA to quickly roam to (and connect to) a target AP by assigning a specific subset or segment of user data context parameters (such as PN, SN, BA, etc.) to a group of candidate APs. Furthermore, the described techniques can be used for seamless roaming, whereby a STA can switch from a serving AP to a target AP without performing a reassociation frame exchange with the target AP.

[0031] Figure 1A schematic diagram of an example wireless communication network 100 is shown. Depending on some aspects, the wireless communication network 100 may be an example of a wireless local area network (WLAN) (such as a Wi-Fi network). For example, the wireless communication network 100 may be a network implementing at least one of the IEEE 802.11 family of wireless communication protocol standards (such as standards defined by the IEEE 802.11-2020 specification or its revisions, including but not limited to 802.11ay, 802.11ax, 802.11az, 802.11ba, 802.11bd, 802.11be, 802.11bf, and 802.11bn). In some other examples, the wireless communication network 100 may be an example of a cellular radio access network (RAN), such as a 5G or 6G RAN implementing one or more cellular protocols (such as those specified in one or more 3GPP standards). In some other examples, the wireless communication network 100 may include a WLAN that operates in an interoperable or converged manner with one or more cellular RANs to provide greater or enhanced network coverage to wireless devices within the wireless communication network 100, or to enable such devices to connect to the core of the cellular network, such as to access network management capabilities and functionality provided by the cellular network core.

[0032] The wireless communication network 100 may include multiple wireless devices, including at least one wireless AP 102 and any number of wireless STAs 104. Although Figure 1 Only one AP 102 is shown, but the wireless communication network 100 may include multiple APs 102. AP 102 may be or represent various different types of network entities, including but not limited to home networking APs, enterprise APs, single-band APs, dual-band simultaneous (DBS) APs, tri-band simultaneous (TBS) APs, standalone APs, non-standalone APs, software-enabled APs (software APs), and multi-link APs (also known as AP MLDs), as well as cellular (such as 3GPP, 4G LTE, 5G, or 6G) base stations or other cellular network nodes, such as Node Bs, evolved Node Bs (eNBs), gNBs, Transmitter Receiver Points (TRPs), or another type of equipment or apparatus included in the radio access network (RAN), including open RAN (O-RAN) network entities, such as central units (CUs), distributed units (DUs), or radio units (RUs).

[0033] Each STA in STA 104 may also be referred to as a mobile station (MS), mobile device, mobile phone, wireless phone, access terminal (AT), user equipment (UE), subscriber station (SS), or subscriber unit, etc. STA 104 can represent a variety of devices such as mobile phones, other handheld or wearable communication devices, netbooks, laptops, tablets, laptops, Chromebooks, augmented reality (AR), virtual reality (VR), mixed reality (MR), or extended reality (XR) wireless headsets or other peripherals, wireless earbuds, other wearable devices, display devices (e.g., televisions, computer monitors, or video game consoles), video game controllers, navigation systems, music or other audio or stereo devices, remote control devices, printers, kitchen appliances (including smart refrigerators) or other home appliances, remote keys (e.g., for passive keyless entry and start (PKES) systems), Internet of Things (IoT) devices, vehicles, etc.

[0034] A single AP 102 and its associated set of STA 104s may be referred to as a Basic Service Set (BSS), which is managed by the respective AP 102. Figure 1 An example coverage area 108 of AP 102 is also shown, which may represent the Basic Service Area (BSA) of wireless communication network 100. The BSA can be identified by STA 104 and other devices through a Service Set Identifier (SSID) and a Basic Service Set Identifier (BSSID), which may be the Media Access Control (MAC) address of AP 102. AP 102 may periodically broadcast a beacon frame (“beacon”) including the BSSID to enable any STA 104 within the wireless range of AP 102 to “associate” or reassociate with AP 102 to establish or maintain a corresponding communication link 106 (also referred to hereinafter as a “Wi-Fi link”) with AP 102. For example, the beacon may include an identifier or indication of the primary channel used by the corresponding AP 102 and a Timing Synchronization Function (TSF) for establishing or maintaining timing synchronization with AP 102. AP 102 can provide access to external networks to various STAs 104 in the wireless communication network 100 via the corresponding communication link 106.

[0035] To establish a communication link 106 with AP 102, each STA 104 is configured to perform a passive or active scanning operation (“scan”) on frequency channels in one or more frequency bands (e.g., 2.4 GHz, 5 GHz, 6 GHz, 45 GHz, or 60 GHz bands). To perform a passive scan, STA 104 listens for beacons transmitted by the corresponding AP 102 at periodic time intervals called Target Beacon Transmission Time (TBTT). To perform an active scan, STA 104 generates probe requests and transmits these probe requests sequentially on each channel to be scanned, and listens for probe responses from AP 102. Each STA 104 can identify, determine, detect, or select an AP 102 to associate with based on the scanning information obtained through passive or active scanning, and perform authentication and association operations to establish a communication link 106 with the selected AP 102. When the association operation is completed, the selected AP 102 assigns an association identifier (AID) to STA 104, and AP 102 uses the association identifier (AID) to track STA 104.

[0036] As wireless networks become increasingly prevalent, STA 104 may have the opportunity to choose from one of many BSSs within its range or from multiple APs 102 that together form an Extended Service Set (ESS) (comprising multiple connected BSSs). For example, wireless communication network 100 may connect to a wired or wireless distribution system that enables multiple APs 102 to connect within such an ESS. Therefore, STA 104 may be covered by more than one AP 102 and may be associated with different APs 102 at different times for different transmissions. Additionally, after associating with an AP 102, STA 104 may periodically scan its surroundings to find a more suitable AP 102 to associate with. For example, STA 104 moving relative to its associated AP 102 may perform a “roaming” scan to find another AP 102 with more desirable network characteristics, such as a larger Received Signal Strength Indicator (RSSI) or reduced traffic load.

[0037] In some implementations, STA 104 may form a network without AP 102 or any other equipment besides STA 104 itself. An example of such a network is an ad hoc network (or wireless ad hoc network). Ad hoc networks may also be referred to as mesh networks or peer-to-peer (P2P) networks. In some implementations, ad hoc networks may be implemented within a larger network, such as wireless communication network 100. In such examples, while STA 104 may be able to communicate with each other via communication link 106 through AP 102, STA 104 may also communicate directly with each other via direct wireless communication link 110. Additionally, two STA 104 may communicate via direct communication link 110, regardless of whether the two STA 104 are associated with and served by the same AP 102. In such ad hoc systems, one or more STAs among STA 104 may assume the role played by AP 102 in the BSS. Such STA 104 may be referred to as the group owner (GO) and may coordinate transmissions within the ad hoc network. Examples of direct wireless communication links 110 include Wi-Fi direct connections, connections established by using Wi-Fi Tunneling Direct Link Establishment (TDLS) links, and other P2P group connections.

[0038] In some networks, AP 102 or STA 104, or both, can support applications associated with high throughput or low latency requirements, or can provide lossless audio to one or more other devices. For example, AP 102 or STA 104 can support applications and use cases associated with ultra-low latency (ULL), such as ULL gaming, or streaming lossless audio and video to one or more personal audio devices (such as peripherals) or AR / VR / MR / XR headsets. In scenarios where users use two or more peripherals, AP 102 or STA 104 can support extended personal audio networks that enable communication with two or more peripherals. Additionally, AP 102 and STA 104 can support additional ULL applications, such as cloud-based applications with both ULL and high throughput requirements (such as VR cloud gaming).

[0039] As indicated above, in some implementations, AP 102 and STA 104 may operate and communicate according to one or more of the IEEE 802.11 wireless communication protocol family of standards (via the corresponding communication link 106). These standards define WLAN radio and baseband protocols for the physical (PHY) layer and MAC layer. AP 102 and STA 104 transmit and receive wireless communications to and from each other in the form of PHY Protocol Data Units (PPDUs) (also referred to below as "Wi-Fi communication" or "wireless packets").

[0040] Each PPDU is a composite structure comprising a PHY preamble and a payload in the form of a PHY Service Data Unit (PSDU). The information provided in the preamble can be used by the receiving device to decode subsequent data in the PSDU. In instances where PPDUs are transmitted via bonded or wideband channels, the preamble field can be copied and transmitted in each of the multiple component channels. The PHY preamble may include both a legacy portion (or "legacy preamble") and a non-legacy portion (or "non-legacy preamble"). The legacy preamble can be used for other purposes such as packet detection, automatic gain control, and channel estimation. The legacy preamble is also typically used to maintain compatibility with legacy equipment. The format, decoding, and information provided therein of the non-legacy portion of the preamble are associated with the specific IEEE 802.11 wireless communication protocol to be used to transmit the payload.

[0041] AP 102 and STA 104 in wireless communication network 100 can transmit PPDUs on unlicensed spectrum, which may be a portion of the spectrum including frequency bands traditionally used by Wi-Fi technologies, such as the 2.4 GHz, 5 GHz, 6 GHz, 45 GHz, and 60 GHz bands. Some specific implementations of AP 102 and STA 104 described herein can also communicate in other frequency bands that can support licensed or unlicensed communication. For example, AP 102 or STA 104, or both, may also be able to communicate in unlicensed operating frequency bands, where multiple operators may have corresponding licenses to operate within the same or overlapping frequency ranges. Such licensed operating bands may be mapped to or associated with the frequency ranges specified for FR1 (410MHz-7.125GHz), FR2 (24.25GHz-52.6GHz), FR3 (7.125GHz-24.25GHz), FR4a or FR4-1 (52.6GHz-71GHz), FR4 (52.6GHz-114.25GHz), and FR5 (114.25GHz-300GHz).

[0042] Each frequency band can include multiple sub-bands and frequency channels (also referred to as sub-channels). For example, PPDUs conforming to revisions of the IEEE 802.11n, 802.11ac, 802.11ax, 802.11be, and 802.11bn standards can be transmitted on one or more frequency bands in the 2.4 GHz, 5 GHz, or 6 GHz bands, each of which is divided into multiple 20 MHz channels. Therefore, these PPDUs are transmitted on physical channels with a minimum bandwidth of 20 MHz, but larger channels can be formed through channel bonding. For example, by bonding multiple 20 MHz channels together, PPDUs can be transmitted on physical channels with bandwidths of 40 MHz, 80 MHz, 160 MHz, 240 MHz, 320 MHz, 480 MHz, or 640 MHz.

[0043] In some implementations, a first wireless device (such as STA 104) may communicate with a second wireless device via a first set of communication links 106 using a first subset of multiple user data context parameters corresponding to a first index assigned to a second wireless device (such as serving AP 102). The first wireless device may roam from the second wireless device to the third wireless device based on the state of the first set of communication links 106 and the state of a second set of communication links 106 between the first wireless device and the third wireless device (such as target AP 102). To roam (e.g., switch) from the second wireless device to the third wireless device, the first wireless device may send user data to the third wireless device using a second subset of multiple user data context parameters corresponding to a second index assigned to the third wireless device (via the second set of communication links 106).

[0044] Figure 2 An example protocol data unit (PDU) 200 capable of wireless communication between a wireless access point (AP) and one or more wireless STAs is shown. For example, the AP and STA can be reference... Figure 1Examples of AP 102 and STA 104 are described. PDU 200 can be configured as a PPDU. As shown, PDU 200 includes a PHY preamble 202 and a PHY payload 204. For example, preamble 202 may include a legacy portion, which itself includes a legacy short training field (L-STF) 206 consisting of two symbols, a legacy long training field (L-LTF) 208 consisting of two symbols, and a legacy signal field (L-SIG) 210 consisting of two symbols. The legacy portion of preamble 202 may be configured according to the IEEE 802.11a wireless communication protocol standard. Preamble 202 may also include a non-legacy portion, which includes one or more non-legacy fields 212, for example, conforming to one or more of the IEEE 802.11 wireless communication protocol standard family.

[0045] L-STF 206 generally enables receiving devices (such as AP 102 or STA 104) to perform coarse timing and frequency tracking, as well as automatic gain control (AGC). L-LTF 208 generally enables receiving devices to perform fine timing and frequency tracking, and also to perform initial estimation of the radio channel. L-SIG 210 generally enables receiving devices to determine (e.g., acquire, select, identify, detect, determine, calculate, or compute) the duration of the PDU and use the determined duration to avoid transmission over the PDU. The legacy portion of the preamble can be modulated according to a binary phase shift keying (BPSK) modulation scheme, including L-STF 206, L-LTF 208, and L-SIG 210. The payload 204 can be modulated according to a BPSK modulation scheme, a quadrature BPSK (Q-BPSK) modulation scheme, a quadrature amplitude modulation (QAM) modulation scheme, or another suitable modulation scheme. Payload 204 may include a PSDU containing a data field (DATA) 214, which in turn may carry higher-level data in the form of, for example, MAC Protocol Data Unit (MPDU) or Aggregated MPDU (A-MPDU).

[0046] In some implementations, a first wireless device (such as STA 104) may communicate with a second wireless device via a first set of communication links 106 using a first subset of multiple user data context parameters corresponding to a first index assigned to a second wireless device (such as serving AP 102). The first wireless device may roam from the second wireless device to the third wireless device based on the state of the first set of communication links 106 and the state of a second set of communication links 106 between the first wireless device and the third wireless device (such as target AP 102). To roam (e.g., switch) from the second wireless device to the third wireless device, the first wireless device may send user data (such as PDU 200) to the third wireless device using a second subset of multiple user data context parameters corresponding to a second index assigned to the third wireless device (via the second set of communication links 106).

[0047] Figure 3 An example physical layer (PHY) protocol data unit (PPDU) 350 capable of being used for communication between a wireless AP and one or more wireless STAs is shown. For example, the AP and STA can be reference... Figure 1Examples of AP 102 and STA 104 are described below. As shown, PPDU 350 includes a PHY preamble (which includes a legacy portion 352 and a non-legacy portion 354) and a payload 356 (which includes a data field 374). The legacy portion 352 of the preamble includes L-STF 358, L-LTF 360, and L-SIG 362. The non-legacy portion 354 of the preamble includes a repetition of L-SIG (RL-SIG) 364 and multiple wireless communication protocol version-related signal fields following RL-SIG 364. For example, the non-legacy portion 354 may include a general signal field (referred to herein as "U-SIG 366") and an EHT signal field (referred to herein as "EHT-SIG 368"). The presence of RL-SIG 364 and U-SIG 366 ensures compatibility with EHT or later versions. STA 104 indicates that PPDU 350 is an EHT PPDU or a PPDU conforming to a new wireless communication protocol (conforming to future IEEE 802.11 wireless communication protocol standards). One or both of U-SIG 366 and EHT-SIG 368 can be constructed as other wireless communication protocol versions above EHT that are associated with a revision of the IEEE standards family and carry version-related information. For example, U-SIG 366 can be used by receiving devices (such as AP 102 and STA 104) to interpret bits in one or more of EHT-SIG 368 or data field 374. Similar to L-STF 358, L-LTF 360, and L-SIG 362, in instances involving the use of bonded channels, the information in U-SIG 366 and EHT-SIG 368 can be copied and transmitted in each of the component 20MHz channels.

[0048] The non-legacy portion 354 also includes additional short training fields (referred to herein as "EHT-STF 370," but which can be constructed for other wireless communication protocol versions above EHT and carry version-specific information for those versions) and one or more additional long training fields (referred to herein as "EHT-LTF 372," but which can be constructed for other wireless communication protocol versions above EHT and carry version-specific information for those versions). EHT-STF 370 can be used for timing and frequency tracking as well as AGC, while EHT-LTF 372 can be used for more refined channel estimation.

[0049] EHT-SIG 368 can be used by AP 102 to identify one or more STAs 104 and notify those STAs that AP 102 has scheduled uplink (UL) or downlink (DL) resources for them. EHT-SIG 368 can be decoded by each compatible STA 104 served by AP 102. EHT-SIG 368 can generally be used by the receiving device to interpret the bits in data field 374. For example, EHT-SIG 368 may include resource element (RU) allocation information, spatial flow configuration information, and per-user (e.g., STA-specific) signaling information. Each EHT-SIG 368 may include a common field and at least one user-specific field. In the context of OFDMA, the common field may indicate the RU distribution across multiple STAs 104, indicate RU assignment in the frequency domain, indicate which RUs are allocated for MU-MIMO transmission and which RUs correspond to OFDMA transmission, and the number of users in the allocation, etc. The user-specific field is assigned to a specific STA 104 and carries STA-specific scheduling information, such as user-specific MCS values ​​and user-specific RU allocation information. This information enables the corresponding STA 104 to identify and decode the corresponding RU in the associated data field 374.

[0050] In some implementations, a first wireless device (such as STA 104) may communicate with a second wireless device via a first set of communication links 106 using a first subset of multiple user data context parameters corresponding to a first index assigned to a second wireless device (such as serving AP 102). The first wireless device may roam from the second wireless device to the third wireless device based on the state of the first set of communication links 106 and the state of a second set of communication links 106 between the first wireless device and the third wireless device (such as target AP 102). To roam (e.g., switch) from the second wireless device to the third wireless device, the first wireless device may send user data (such as PPDU 350) to the third wireless device (via the second set of communication links 106) using a second subset of multiple user data context parameters corresponding to a second index assigned to the third wireless device.

[0051] Figure 4 A hierarchical format of an example PPDU capable of being used for communication between a wireless AP and one or more wireless STAs is shown. For example, the AP and STA can be references. Figure 1Examples of AP 102 and STA 104 described. As described, each PPDU 400 includes a PHY preamble 402 and a PSDU 404. Each PSDU 404 may represent (or “carry”) one or more MAC Protocol Data Units (MPDUs) 416. For example, each PSDU 404 may carry an aggregated MPDU (A-MPDU) 406, which includes an aggregation of multiple A-MPDU subframes 408. Each A-MPDU subframe 406 may include an MPDU frame 410 that includes a MAC delimiter 412 and a MAC header 414 preceding the accompanying MPDU 416, which includes the data portion (“payload” or “frame body”) of the MPDU frame 410. Each MPDU frame 410 may also include a Frame Check Sequence (FCS) field 418 for error detection (e.g., the FCS field may include Cyclic Redundancy Check (CRC)) and padding bits 420. MPDU 416 may carry one or more MAC Service Data Units (MSDUs) 426. For example, MPDU 416 may carry an aggregated MSDU (A-MSDU) 422, which comprises multiple A-MSDU subframes 424. Each A-MSDU subframe 424 contains a corresponding MSDU 430, which is preceded by a subframe header 428 and, in some specific implementations, followed by padding bits 432.

[0052] Returning to reference MPDU frame 410, MAC delimiter 412 can be used as a marker to indicate the start of associated MPDU 416 and the length of associated MPDU 416. MAC header 414 may include multiple fields containing information defining or indicating the characteristics or attributes of the data encapsulated within the frame body. MAC header 414 includes a duration field indicating the duration from the end of the PPDU to at least the end of the acknowledgment (ACK) or BA to be sent by the receiving radio device for that PPDU. The use of the duration field is to preserve the radio medium until the indicated duration and to enable the receiving device to establish its Network Allocation Vector (NAV). MAC header 414 also includes one or more fields indicating the address of the data encapsulated within the frame body. For example, MAC header 414 may include a combination of source address, transmitter address, receiver address, or destination address. MAC header 414 may also include a frame control field containing control information. The frame control field may specify the frame type, such as a data frame, control frame, or management frame.

[0053] Some wireless devices (including both AP and STA, such as reference) Figure 1The described AP 102 and STA 104 are capable of multi-link operation (MLO). In some implementations, MLO supports establishing multiple distinct communication links (such as a first link in the 2.4 GHz band, a second link in the 5 GHz band, and a third link in the 6 GHz band) between STA 104 and AP 102, and concurrently and dynamically exchanging packets on one or more communication links. Each communication link may support one or more sets of channels or logical entities. In some implementations, each communication link associated with a given wireless device may be associated with a corresponding radio component of the wireless device, which may include one or more transmit / receive (Tx / Rx) chains, including or coupled to one or more physical antennas, or including signal processing components and other components. A device with MLO capability may be referred to as an MLD. An MLD may include a single upper MAC layer and may include, for example, three independent lower MAC layers and three associated independent PHY layers for the corresponding links in the 2.4 GHz, 5 GHz, and 6 GHz bands. This architecture can implement a single association process and security context. AP MLDs may include multiple APs, each configured to communicate with a corresponding STA among a plurality of STAs 104 that are not AP MLDs (also referred to as "STA MLDs") on a respective communication link. STA MLDs may communicate with AP MLDs at a given time via one or more of the multiple communication links. MLDs may independently compete for access on each of the communication links, which reduces latency by allowing the MLD to send its packets on the first communication link that becomes available.

[0054] Another feature of MLO is traffic steering and QoS characterization, which achieves latency reduction and other QoS enhancements by mapping traffic flows with different latency or other requirements to different links. For example, traffic with low latency requirements can be mapped to radio links operating in the 6 GHz band, and more latency-tolerant traffic can be mapped to radio links operating in the 2.4 GHz or 5 GHz bands.

[0055] One type of MLO is Alternating Multiple Link, where an MLD can simultaneously listen to two different high-performance channels. When an MLD has traffic to transmit, it can use the first channel with access opportunities (such as TXOP). Although an MLD may only use one channel for receiving or transmitting at a time, having access opportunities on two different channels provides low latency during network congestion.

[0056] Another type of MLO is Multi-Link Aggregation (MLA), where traffic associated with a single STA 104 is transmitted simultaneously and in parallel across multiple communication links to maximize the utilization of available resources, thereby achieving higher throughput. This is similar to carrier aggregation in cellular space. That is, transmission, or portions thereof, can occur simultaneously and in parallel through two or more links during at least some time durations. In some implementations, the parallel wireless communication links may support synchronous transmission. In some other examples, or during some other time durations, transmissions via links may be parallel, but not synchronous or concurrent. In some implementations or time durations, two or more of these links may be used for communication between wireless devices in the same direction (such as all uplinks or all downlinks). In some other examples or time durations, two or more of these links may be used for communication in different directions. For example, one or more links may support uplink communication, and one or more links may support downlink communication. In such examples, at least one of the wireless devices operates in full-duplex mode. Generally speaking, full-duplex operation enables bidirectional communication, in which at least one wireless device can simultaneously transmit and receive.

[0057] MLA can be implemented in several ways. In some implementations, MLA can be packet-based. For packet-based aggregation, frames of a single service stream (such as all services associated with a given service identifier (TID)) can be transmitted concurrently across multiple communication links. In some other examples, MLA can be stream-based. For stream-based aggregation, a single available communication link from among multiple available communication links can be used to transmit each service stream (such as all services associated with a given TID). As an example, a single STA MLD can access a web browser while streaming video in parallel. Services associated with web browser access can be communicated via a first communication link, while services associated with the video stream can be communicated in parallel via a second communication link (such that at least some of the data can be transmitted concurrently on the first channel with the data transmitted on the second channel).

[0058] In some other examples, MLA can be implemented as a hybrid of flow-based and packet-based aggregation. For example, MLD can employ flow-based aggregation when multiple traffic flows are created, and packet-based aggregation in other cases. The determination of switching between MLA techniques or modes can be additionally or alternatively correlated with other metrics, such as time of day, network traffic load, or battery level of wireless devices, and other factors or considerations.

[0059] To support MLO technology, the AP MLD and STA MLD can exchange information about supported MLO capabilities (such as supported aggregation types or supported frequency bands, etc.). In some implementations, this exchange can occur via beacon signals, probe requests or responses, association request or response frames, dedicated action frames or Operation Mode Indicators (OMIs), and other examples. In some implementations, the AP MLD can designate a given channel in a given frequency band as an anchor channel (such as a channel on which the AP MLD transmits beacons and other management frames). In such examples, the AP MLD may also transmit beacons (such as beacons containing less information) on other channels for discovery purposes.

[0060] MLO technology offers several benefits to WLANs. For example, MLO can improve user-aware throughput (UPT) (e.g., by rapidly refreshing the per-user transmit queue). Similarly, MLO can improve throughput by improving the utilization of available channels and can increase spectrum utilization (e.g., by increasing the bandwidth-time product). Furthermore, MLO can enable smooth transitions between multi-band radio components (e.g., where each radio component can be associated with a given RF band) or implement a framework for separating control and data channels. Other benefits of MLO include reduced modem power-on time, which can benefit wireless devices in terms of power consumption. Another benefit of MLO is increased multiplexing opportunities in the case of a single BSS. For example, multi-link aggregation can increase the number of users transmitted per multiplexed segment served by a multi-link AP MLD.

[0061] In some implementations, a first wireless device (such as STA 104) may communicate with a second wireless device via a first set of communication links 106 using a first subset of multiple user data context parameters corresponding to a first index assigned to a second wireless device (such as serving AP 102). The first wireless device may roam from the second wireless device to the third wireless device based on the state of the first set of communication links 106 and the state of a second set of communication links 106 between the first wireless device and the third wireless device (such as target AP 102). To roam (e.g., switch) from the second wireless device to the third wireless device, the first wireless device may send user data (such as PPDU 400) to the third wireless device (via the second set of communication links 106) using a second subset of multiple user data context parameters corresponding to a second index assigned to the third wireless device.

[0062] Figure 5An example of a signaling diagram 500 supporting context acquisition for seamless roaming is shown. The signaling diagram 500 may implement one or more aspects of the wireless communication network 100. For example, the signaling diagram 500 includes AP 102-a (such as a non-MLD AP) and AP 102-b (such as an MLD AP), AP 102-c, AP 102-d, AP 102-e, and AP 102-f, which may be as shown in the reference. Figure 1 Examples of various aspects of AP 102 are shown and described. Similarly, signaling diagram 500 includes STA 104-a (such as a non-APMLD STA), STA 104-b, STA 104-c, and STA 104-d (such as a non-MLD non-AP STA), which can be as referenced. Figure 1 Examples of STA 104 shown and described.

[0063] In some WLANs (such as wireless communication network 100), when the signal strength of a serving AP (such as AP 102-d) is weakening, a STA (such as STA 104-c) can roam to a target AP (such as AP 102-e) with better signal quality without waiting for buffered / transmitting DL packets to arrive from the serving AP. Roaming can be used for upper-layer applications that are unaffected by packet loss during roaming, and for upper-layer applications that can handle / process out-of-order packets (between the serving AP and the target AP) during roaming. Roaming can also be used for periodic extended reality (XR) services, which may have data bursts arriving every 16.66 ms. After a burst of traffic, a STA may not expect more traffic until the next burst, so the STA can take advantage of this gap to roam to a better AP without data interruption.

[0064] As used herein, the term "AP" encompasses both a non-MLD AP (e.g., an AP operating on a single communication link) and an AP MLD 504 operating on more than one communication link. Similarly, the term "STA" encompasses both a non-MLD non-AP STA (such as an STA operating on a single communication link) and a non-AP MLD operating on more than one communication link. Therefore, in the following description of signaling diagram 500, when referring to communication between an STA and an AP, "STA" can be a non-MLD non-AP STA (e.g., a non-AP STA not attached to a non-AP MLD, such as STA 104-d) or a non-AP MLD STA (such as STA 104-c attached to a non-AP MLD 506), and "AP" can be a non-MLD AP (such as AP 102-a) or an MLD AP (such as AP 102-d attached to AP MLD 504-a or AP 102-e attached to AP MLD 504-b).

[0065] To migrate from a serving AP (such as AP 102-d) to a target AP (such as AP 102-e), the target AP may need to know various user data context parameters associated with the STA, such as SN, PN, PN, and / or the set of encryption keys used by the STA. For latency-sensitive operations and applications, the serving AP may not have enough time to transfer the complete context to the target AP before the active user data transfer can begin at the target AP.

[0066] In some implementations, the encryption key can be asynchronously prefetched to the target AP. As the STA moves closer to some potential target APs, the current encryption key in use can be prefetched to those candidate target APs, so that if the STA eventually roams to one of those APs, both the target AP and the STA will have the correct encryption key and can immediately begin transmission. Asynchronous encryption key fetching may be suitable for roaming operations (because the encryption key does not change frequently after association), but other parameters (such as SN, PN, and BA) may change rapidly during active data sessions. The target AP may need to obtain / fetch the latest values ​​of these parameters before active user data communication with the STA can begin. However, in some implementations, this may be infeasible due to communication latency between APs (which may exceed 20ms). Therefore, new context acquisition schemes may be needed to achieve instantaneous user data communication with the target AP (without waiting for the serving AP to transfer these parameters to the target AP).

[0067] According to the described technique, the current 48-bit PN space can be divided (e.g., segmented) into PN segments of equal size, where each PN segment is associated with a corresponding PN index. For example, the 8 most significant bits (MSB) of the 48-bit PN can be used to represent the index of a given PN segment. Therefore, each PN segment can have 2 40 The length of the PN index is given by several possible values, and the PN index can range from 0 to 256. In the context of signaling diagram 500, a STA can have one serving AP and zero or more candidate / target APs. The serving AP of the STA can use one of the PN segments to communicate with the STA. Each candidate AP can be assigned a different PN segment, which is assigned but not yet activated / used for communication with the STA.

[0068] The currently used index (index_in_use) can be equal to the index (PN_index) of the PN segment currently used by the serving AP and the STA. The index assigned to another candidate / target AP can be represented as index_assigned[i] = the PN index assigned to AP[i], where i is the index of the AP in the candidate AP set. To initialize the PN index, index_in_use can be set to 0, and index_assigned[k] can be set to 0+k, where k equals 0, 1, 2, etc. When the STA roams / associates with AP[j] (where AP[j] is one of the candidate APs before roaming), index_in_use can be set to index_assigned[j]. Therefore, the index assigned to AP[j] becomes the used index (index_in_use++). For k = 0 to N-1 (where N is the number of candidate APs after roaming), index_assigned[k] can be set to index_in_use+k. Alternatively, index_assigned[k] can be set to index_in_use.

[0069] A receiver (such as AP 102-e) can instantiate a separate full 48-bit PN counter for each AP (initialized by the PN segment in use). Replay-resistant PN checks can be performed using the 48-bit PN counter corresponding to the AP on which packets are received. The PN counter can be initialized based on the PN segment corresponding to the AP's index_in_use. In some implementations, the AP and STA can initiate a key update process when all PN values ​​within a PN segment are exhausted and / or when index_in_use reaches the total number of PN segments. During roaming, the STA can ensure that sufficient time has elapsed for any UL packets 508 recently delivered to the serving AP (e.g., AP 102-d) to be delivered to the gateway, and then transmit a Multi-Link (ML) Add Link Request (REQ) frame 510 to the target AP (e.g., AP 102-e). At this point, the SN is reset to 0 (or a predetermined value higher than the current sequence number) for the target AP, and the STA can immediately begin active user data exchange with the target AP (using the PN segment assigned to the target AP). The STA can wait before transmitting the ML Add Link REQ frame 510 to avoid UL packets from the serving AP reaching the gateway after a data path switch, as UL packets from the previous serving AP may trigger a data path switch back to the original path.

[0070] Examples of PN index assignments for candidate / target APs are shown in Tables 1 and 2 below. For the example shown in Table 1, AP1 (e.g., AP 102-d), AP2 (e.g., AP 102-c), AP3 (e.g., AP 102-e), and AP4 (e.g., AP 102-f) can be assigned and distributed across a single profile. When a STA moves from AP1 toward AP2 or AP3 and roams to a new serving AP (e.g., AP3), the PN indexes assigned to other APs can be updated / shifted accordingly. Some PN segments (e.g., PN segments 0, 2, and 5) can be used, while others (e.g., PN segments 1, 3, and 4) may not be used. For the example shown in Table 2, when a STA moves along an AP and roams from AP to AP, the target AP sequentially uses PN segments 0, 1, and 2.

[0071]

[0072] surface 1 : PN Index and Correspondence PN Section assignment

[0073] surface 2 : PN Index and Correspondence PN Section assignment

[0074] As the STA moves along an AP and transitions from one AP to another, the network can (e.g., via an 802.11be link recommendation frame) recommend candidate APs to non-AP MLD 506, and as the STA roams to different APs, the network can assign a different PN segment index to each candidate AP. In some implementations, it may be desirable for the STA to complete all DL / UL packets sent to / received from the serving AP in advance. Specifically, the STA can wait to ensure that no more UL packets 508 are sent from the serving AP to the gateway (by completing all UL packets and suppressing the transmission of new UL packets to the serving AP).

[0075] In some implementations, the SN used by the STA can be modified by a certain amount (e.g., offset or shift) for transmissions to / from the target AP. For example, if the serving AP is currently using SN 45, the target AP can start using SN value 100. Therefore, transmissions from the serving AP during short (e.g., roaming) periods may include PN 46, 47, 48, etc., while transmissions from the target AP may include PN values ​​100, 101, 102, etc. Using this scheme, the SN spaces for the two APs remain different, and any retransmissions from either the serving or target AP can occur without problems. Furthermore, when a non-AP STA has completed its transition to the target AP, the target AP can transmit a Block Acknowledgment Request (BAR) frame to advance the SN to 100, causing all frames received from the previous (serving) AP to be passed to the higher layer, and any gaps (e.g., 48 to 99) to be ignored.

[0076] Subsequently, the STA can use the PN value within the assigned PN segment for the target AP to transmit the ML Add Link REQ frame 510 to the target AP. Therefore, the target AP's PN segment becomes the index in use. The STA can obtain the target AP's Group Temporary Key (GTK), Integrity Group Temporary Key (IGTK), and Broadcast Integrity Group Temporary Key (BIGTK) from the ML Add Link Response (RESP) frame 512. Furthermore, the target AP can transmit a path switching frame to the gateway, and the gateway can switch the STA's data patch to the target AP. The network can reassign the new PN segment and index to the candidate AP and indicate these assignments to the STA after roaming is complete.

[0077] In some implementations, the serving AP (or centralized controller) can provide a security key associated with a specific client / STA to neighboring APs belonging to the same Single Mobility Domain (SMD) MLD 502. Similarly, the serving AP can provide one or more of the PN index or SN offset to each neighboring AP. In some implementations, this exchange can occur over the air between APs, in which case parameters can be signaled via one or more frames, elements, and fields. The centralized controller can supply security keys to the APs, thus protecting the over-the-air transmission. Alternatively, communication between APs can be performed via a secure backhaul connection. For example, the controller can handle the supply of encryption keys, PN / SN index / offset assignments, etc., to each client.

[0078] Figure 6 An example of a process flow 600 supporting context acquisition for seamless roaming is shown. Process flow 600 can be implemented as described in the reference. Figure 1 and Figure 5 One or more aspects of the wireless communication network 100 or signaling diagram 500 shown and described. For example, process flow 600 includes wireless devices 602 (such as non-AP STA 102 or non-AP MLD 506), wireless devices 604 (such as a first non-MLD AP 102 or AP MLD 504), and wireless devices 606 (such as a second non-MLD AP 102 or APMLD 504), which can communicate with each other via one or more communication links 106. In some specific implementations, wireless device 604 can communicate with wireless device 606 via gateway 608.

[0079] At 610, wireless device 602 (e.g., a first wireless device) can transmit user data (such as UL packet 508) to wireless device 604 via a first set of communication links between wireless device 602 and wireless device 604 (e.g., a second wireless device). Wireless device 602 can transmit user data to wireless device 604 using a first set of user data context parameters (such as segments of PN) associated with a first index assigned to wireless device 604. In some implementations, different sets of data context parameters can be assigned to each candidate or neighboring AP of wireless device 602.

[0080] At 612, wireless device 604 can forward user data from wireless device 602 to gateway 608, which can then forward / route the user data accordingly. In some implementations, a centralized controller can communicate with wireless device 604 and / or wireless device 606 via gateway 608. For example, the centralized controller can assign a corresponding PN segment and a corresponding index to each candidate AP associated with the STA of wireless device 602. The specific index (and corresponding segment of the PN) assigned to wireless device 606 may differ from the index (and corresponding segment of the PN) assigned to wireless device 604.

[0081] At 614, wireless device 602 may determine to roam (e.g., switch) from wireless device 604 to wireless device 606 based on, for example, the location of wireless device 602 relative to wireless device 604 and / or wireless device 606, the signal strength of wireless device 604 relative to wireless device 606, etc. To initiate a transfer from wireless device 604 to wireless device 606, wireless device 602 may send one or more packets (such as ML add link REQ frame 510) to wireless device 606 via a second set of communication links between wireless device 602 and wireless device 606. Wireless device 602 may use a second set of user data context parameters (such as PN, SN, or BA) associated with an index assigned to wireless device 606 to send one or more packets.

[0082] In some implementations, wireless device 602 may include a second index (such as a PN index) of wireless device 604 in the 48-bit PN field of the frame. In other implementations, the second index may be carried in a separate portion of the frame, and the 48-bit PN value may be carried in the same location. On the receiver side, during replay checking, wireless device 606 may combine two values ​​(e.g., the PN value and the PN index), where the index field is the MSB of the common / combined value. Upon receiving one or more packets that include or indicate a second set of user data context parameters, wireless device 606 may send one or more messages, frames, or signals (such as ML Add Link RESP frame 512) to wireless device 602 at 616. Messages, frames, and / or signals from wireless device 606 may indicate various user data context parameters for use by wireless device 602, such as GTK, IGTK, and BIGTK, etc.

[0083] After exchanging data with wireless device 602 using the second set of user data context parameters assigned to wireless device 606, wireless device 606 can transmit a path switching frame to gateway 608 at 618. This prompts gateway 608 to switch the current data path used by wireless device 602 from wireless device 604 to wireless device 606 at 620. In some implementations, wireless device 602 can wait until a threshold time has elapsed before initiating an ML add link REQ / RESP frame exchange with wireless device 606, so that uplink packets forwarded from wireless device 604 to gateway 608 (at 612) do not cause the gateway to switch the data path back to wireless device 604.

[0084] At 622, gateway 608 can reassign an index (and corresponding user data context parameters) to wireless device 604 after switching the current data path of wireless device 602 from wireless device 604 to wireless device 606. For example, gateway 608 can assign new PN segments (and corresponding PN indexes) to wireless device 604 and other targets / candidate APs for the STA of wireless device 602. In some implementations, the new / updated index assignment can be delivered to wireless device 602 via wireless device 606 currently serving wireless device 602.

[0085] In some implementations, process flow 600 may include dividing the 48-bit PN space into segments indexed by PN segment indices. The existing 48-bit PN space can be used to represent PN segment indices and PN segments. Alternatively, the 48-bit PN space may be extended to a larger PN space. In some implementations, the network may pre-assign PN segments to each candidate AP (as shown in Table 1). During roaming, the network may inform the target AP of the currently used highest PN segment index, so that the target AP can use the next index (as shown in Table 2).

[0086] In some specific implementations, the PN / SN direction can be direction-specific. For example, by Figure 6 The PN or SN values ​​used by one or more wireless devices in the example depicted may be different for UL and DL frames. Furthermore, the SN space may be TID-specific, while the PN space may be shared across all TIDs.

[0087] Figure 7 A block diagram 700 is shown of a first wireless device 720 supporting context acquisition for seamless roaming. The first wireless device 720 may be as shown in the reference. Figures 2 to 6Examples of various aspects of the first wireless device described herein. The first wireless device 720 or its various components may be examples of parts for performing various aspects of context acquisition for seamless roaming as described herein. For example, the first wireless device 720 may include a first user context component 725, a device roaming component 730, a second user context component 735, a device roaming component 740, an index reassignment component 745, or any combination thereof. Each of these components, or its components or sub-components (e.g., one or more processors, one or more memories, processor circuitry, memory circuitry), may communicate with each other directly or indirectly (e.g., via one or more buses).

[0088] According to the examples disclosed herein, the first wireless device 720 may support wireless communication. A first user context component 725 can be configured or configured to communicate with the second wireless device via a first set of communication links between the first and second wireless devices using a first subset of multiple user data context parameters corresponding to a first index assigned to the second wireless device. A device roaming component 730 can be configured or configured to roam from the second wireless device to the third wireless device based on the state of the first set of communication links and the state of a second set of communication links between the first and third wireless devices, wherein roaming includes sending or receiving user data via the second set of communication links using a second subset of multiple user data context parameters corresponding to a second index assigned to the third wireless device. A second user context component 735 can be configured or configured to communicate with the third wireless device via the second set of communication links based on roaming from the second wireless device to the third wireless device using a second subset of multiple user data context parameters.

[0089] In some implementations, in order to support the transmission or reception of user data, the second user context component 735 can be configured or configured to use a second subset of a plurality of user data context parameters to transmit or receive packets via a second set of communication links, wherein the user data context parameters include at least one of an encryption key, PN, SN, or BA associated with a second index assigned to a third wireless device.

[0090] In some implementations, the first user context component 725 can be configured or be configured to obtain indications of multiple user data context parameters that are divided into two or more subsets associated with corresponding indexes, each subset including multiple values ​​associated with the corresponding index.

[0091] In some specific implementations, in order to support the transmission or reception of user data, the second user context component 735 can be configured or be configured to transmit or receive a message containing a PN field associated with a second index assigned to a third wireless device via a second set of communication links, wherein a first number of bits in the PN field indicates the second index, and a second number of bits in the PN field indicates a PN within a PN segment associated with the second index.

[0092] In some implementations, the PN field is 48 bits long. In some implementations, the 8 most significant bits of the PN field indicate the second index. In some implementations, the remaining 40 bits of the PN field indicate the PN within the PN segment associated with the second index.

[0093] In some specific implementations, in order to support the transmission or reception of user data, the second user context component 735 can be configured to, or be configured to, transmit or receive frames via a second set of communication links containing a PN associated with a second subset of multiple user data context parameters and a separate field indicating a second index assigned to a third wireless device.

[0094] In some implementations, the first wireless device includes a non-AP MLD, a STA attached to a non-AP MLD, or a non-MLD, non-AP STA. In some implementations, the second wireless device includes a first non-MLD AP or a first AP MLD. In some implementations, the third wireless device includes a second non-MLD AP or a second AP MLD.

[0095] In some implementations, the first AP includes the STA's serving AP. In some implementations, the second AP includes the candidate or target AP to which the STA is roaming.

[0096] In some implementations, in order to support communication with a second wireless device, the second user context component 735 can be configured to or be configured to send or receive one or more packets via a first set of communication links, the one or more packets including a PN associated with a first index of a PN segment currently used for servicing communication between the AP and the STA.

[0097] In some implementations, in order to support the sending or receiving of user data, the second user context component 735 can be configured to or be configured to send or receive one or more packets via a second set of communication links, the one or more packets including a PN within a PN segment associated with a second index assigned to a candidate or target AP.

[0098] In some specific implementations, each candidate or target AP of the STA is assigned a different subset of user data context parameters from multiple user data context parameters.

[0099] In some specific implementations, a first subset of multiple user data context parameters includes a segment of the PN that can be used for communication between the second wireless device and the first wireless device.

[0100] In some specific implementations, a second subset of multiple user data context parameters is not used until the first wireless device roams from the second wireless device to the third wireless device.

[0101] In some implementations, in order to support roaming from a second wireless device to a third wireless device, the device roaming component 740 can be configured or be configured to establish a connection with the third wireless device without performing a reassociation frame exchange with the third wireless device.

[0102] In some specific implementations, a second index is assigned to a third wireless device based on a first index assigned to a second wireless device serving a first wireless device.

[0103] In some specific implementations, the second user context component 735 can be configured or configured to communicate with the third wireless device via a second set of communication links using a second subset of multiple user data context parameters, depending on roaming from the second wireless device to the third wireless device.

[0104] In some implementations, the index reassignment component 745 can be configured or be configured to receive an indication that a third index corresponding to a third subset of multiple user data context parameters has been reassigned to a second wireless device that previously served the first wireless device.

[0105] In some specific implementations, the value of the third index is a function of the second index associated with the third wireless device now serving the first wireless device.

[0106] In some implementations, in order to support the transmission or reception of user data, the second user context component 735 can be configured or be configured to transmit one or more packets to a third wireless device via a second set of communication links in association with a threshold amount of time elapsed relative to a first set of communication links transmitted via a first set of communication links.

[0107] In some implementations, in order to support the sending or receiving of user data, the second user context component 735 can be configured or be configured to perform active user data exchange with the target AP of the third wireless device after the SN for the third wireless device is set to a predetermined value higher than the current sequence number, wherein the active user data exchange is performed using a PN segment associated with the second index assigned to the third wireless device.

[0108] In some implementations, to support roaming, the device roaming component 740 can be configured or configured to send a first set of packets using a first set of SNs associated with a first index assigned to a second wireless device. In some implementations, to support roaming, the device roaming component 740 can be configured or configured to send a second set of packets using a second set of SNs associated with a second index assigned to a third wireless device, wherein there is an offset between the first set of SNs and the second set of SNs.

[0109] In some implementations, in order to support communication with a second wireless device, the second user context component 735 can be configured or be configured to receive, via a first set of communication links, a link recommendation message indicating one or more candidate APs for the first wireless device, wherein each of the one or more candidate APs is assigned a different PN index for multiple user data context parameters.

[0110] In some specific implementations, in order to support communication with a third wireless device, the second user context component 735 can be configured or be configured to send ML add link REQ frames to the third wireless device via a second set of communication links using one or more PN values ​​from a second subset of multiple user data context parameters assigned to the third wireless device.

[0111] In some specific implementations, in order to support communication with a third wireless device, the second user context component 735 can be configured or be configured to receive ML Add Link RESP frames from the third wireless device via a second set of communication links. The ML Add Link RESP frames indicate a set of encryption keys to be used for communication with the target AP of the third wireless device.

[0112] Figure 8 A block diagram 800 is shown illustrating a third wireless device 820 supporting context acquisition for seamless roaming. The third wireless device 820 may be as shown in the reference... Figures 2 to 6 Examples of various aspects of the described third wireless device. The third wireless device 820 or its various components may be examples of parts for performing various aspects of context acquisition for seamless roaming as described herein. For example, the third wireless device 820 may include an assignment instruction component 825, a user data context component 830, a connection establishment component 835, a PN segment component 840, a key reconstruction component 845, a gateway communication component 850, a backhaul connection component 855, a BAR frame component 860, or any combination thereof. Each of these components, or its components or sub-components (e.g., one or more processors, one or more memories), may communicate with each other directly or indirectly (e.g., via one or more buses).

[0113] According to the examples disclosed herein, the third wireless device 820 may support wireless communication. The assignment indication component 825 can be configured or configured to obtain an indication of a second index assigned to the third wireless device, the second index corresponding to a second subset of a plurality of user data context parameters that can be used for communication with the first wireless device. The user data context component 830 can be configured or configured to receive user data via a second set of communication links between the third wireless device and a first wireless device roaming from the second wireless device to the third wireless device, the user data indicating a second subset of a plurality of user data context parameters corresponding to the second index assigned to the third wireless device, wherein a first subset of the plurality of user data context parameters corresponds to a first index assigned to the first wireless device from which it is roaming. The connection establishment component 835 can be configured or configured to, based on user data received from the first wireless device roaming from the second wireless device to the third wireless device, communicate with the first wireless device via the second set of communication links using the second subset of the plurality of user data context parameters corresponding to the second index assigned to the third wireless device.

[0114] In some implementations, the PN segment component 840 can be configured to, or be configured to, instantiate a corresponding 48-bit PN counter for each AP associated with the first wireless device, wherein the corresponding 48-bit PN counter is initialized based on the first PN segment currently used for communicating with the first wireless device.

[0115] In some implementations, the PN segment component 840 can be configured or configured to perform an anti-replay PN check using a corresponding 48-bit PN counter associated with the AP of a third wireless device that receives user data from the first wireless device.

[0116] In some implementations, to support the reception of user data, the user data context component 830 can be configured or configured to receive, via a second set of communication links, a frame containing a PN associated with a second subset of multiple user data context parameters and a separate field indicating a second index assigned to a third radio device. In some implementations, to support the reception of user data, the PN segment component 840 can be configured or configured to perform a replay check by combining the PN with the second index.

[0117] In some implementations, the key reconstruction component 845 can be configured or configured to perform a key reconstruction process between a first wireless device and a third wireless device based on the number of available PN values ​​in a second subset of multiple user data context parameters, the number of remaining PN segments or subsets in the multiple user data context parameters, or both.

[0118] In some implementations, the gateway communication component 850 can be configured to send or receive one or more packets via a gateway between the second and third wireless devices before receiving user data from the first wireless device via a second set of communication links between the first and third wireless devices.

[0119] In some implementations, the gateway communication component 850 can be configured or be configured to send a path switching frame via the gateway associated with switching the data path of the first wireless device from the second wireless device to the third wireless device.

[0120] In some implementations, the user data context component 830 can be configured or configured to receive from the centralized controller or serving AP of the first wireless device one or more frames, elements or fields indicating at least one of a security key, PN index or SN offset for the first wireless device, wherein communication with the first wireless device via a second set of communication links is based on one or more frames, elements or fields.

[0121] In some implementations, the security key for the first wireless device is securely supplied by a centralized controller. In some implementations, the user data context component 830 can be configured or is configured to send one or more frames, elements, or fields indicating at least one of the security key, PN index, or SN offset for the first wireless device to a set of neighboring APs attached to the SMD multilink device.

[0122] In some implementations, the backhaul connection component 855 can be configured or configured to receive a message indicating at least one security key, PN index, or SN offset for the first wireless device via a secure backhaul connection between the third wireless device and the centralized controller, wherein the at least one security key is supplied by the centralized controller.

[0123] In some specific implementations, the BAR frame component 860 can be configured or be configured to send a BAR frame to the first wireless device via a second set of communication links after the first wireless device has successfully transitioned from the second wireless device to the third wireless device.

[0124] Figure 9 A flowchart illustrating a method 900 for supporting context acquisition for seamless roaming is shown. The operation of method 900 may be implemented by a first wireless device or its components as described herein. For example, the operation of method 900 may be implemented by reference to... Figure 6 The wireless device 602 shown and described performs this function. In some embodiments, the first wireless device may execute a set of instructions to control the functional elements of the first wireless device to perform the described function. Additionally or alternatively, the first wireless device may use dedicated hardware to perform aspects of the described function.

[0125] At 905, the first wireless device can use the same as that assigned to the second wireless device (such as reference). Figure 6 The wireless device 604, as shown and described, communicates with the second wireless device via a first set of communication links between the first and second wireless devices using a first subset of multiple user data context parameters (such as segments of PN values) corresponding to a first index. In some specific implementations, aspects of the operation of 905 may be derived from references... Figure 7 The first user context component 725, as described, is used for execution.

[0126] At 910, the first wireless device can, based on the state of the first set of communication links and based on the first wireless device and the third wireless device (such as reference...), Figure 6 The state of the second set of communication links between the illustrated and described wireless devices (606) is used to roam from the second wireless device to the third wireless device, wherein roaming includes sending user data (such as references) to the third wireless device via the second set of communication links using a second subset of multiple user data context parameters corresponding to a second index assigned to the third wireless device. Figure 5 The ML added link REQ frame 510 is shown and described. In some specific implementations, aspects of the operation of 910 may be determined by reference to [reference]. Figure 7 The described device roaming component 730 is used to perform this.

[0127] At 915, the first wireless device can roam from the second wireless device to the third wireless device via a second set of communication links (such as references) based on a second subset using multiple user data context parameters. Figure 1 The communication link 106 shown and described communicates with a third wireless device. In some specific implementations, aspects of the operation of 915 may be determined by reference to [reference needed]. Figure 7 The second user context component 735, as described, is used for execution.

[0128] Figure 10 A flowchart illustrating a method 1000 for supporting context acquisition for seamless roaming is shown. The operation of method 1000 can be implemented by a third wireless device or its components as described herein. For example, the operation of method 1000 can be implemented by, as referenced... Figures 2 to 6 and Figure 8 The wireless device 606 shown and described performs this function. In some embodiments, the third wireless device may execute an instruction set to control the functional elements of the third wireless device to perform the described function. Additionally or alternatively, the third wireless device may use dedicated hardware to perform aspects of the described function.

[0129] At 1005, the third wireless device can obtain an indication of a second index assigned to it, the second index corresponding to an index that can be used with the first wireless device (such as a reference). Figure 5 The second subset of multiple user data context parameters (such as the PN value segment) for communication shown and described in the non-AP MLD 506 is illustrated. In some specific implementations, aspects of the operation of 1005 may be determined by reference to [reference]. Figure 8 The described assignment instruction component 825 is used to perform this task.

[0130] At point 1010, the third wireless device can communicate with the second wireless device (such as a reference device) via the third wireless device. Figure 6 The wireless device 604 shown and described roams to the second set of communication links between the first wireless device and the third wireless device to receive user data (such as references). Figure 5 The illustrated and described ML add link REQ frame 510 indicates that the user data indicates a second subset of a plurality of user data context parameters corresponding to a second index assigned to a third wireless device, wherein a first subset of the plurality of user data context parameters corresponds to a first index assigned to a first wireless device from which the second wireless device is roaming. In some specific implementations, aspects of the operation of 1010 may be provided by reference to [reference]. Figure 8 The user data context component 830 is described and executed.

[0131] At 1015, the third wireless device may, based on user data received from the first wireless device roaming from the second wireless device to the third wireless device, use a second subset of multiple user data context parameters corresponding to the second index assigned to the third wireless device to communicate via a second set (such as reference) of the communication link. Figure 1 The communication link 106 shown and described communicates with the first wireless device. In some specific implementations, aspects of the operation of 1015 may be determined by reference to [reference needed]. Figure 8 The described connection establishment component 835 is used to perform this.

[0132] The following provides an overview of the terms of this disclosure: Clause 1: A first wireless device, the first wireless device comprising: a processing system including processor circuitry and memory circuitry storing code, the processing system being configured to cause the first wireless device to: communicate with a second wireless device via a first set of communication links between the first wireless device and the second wireless device using a first subset of a plurality of user data context parameters corresponding to a first index assigned to the second wireless device; roam from the second wireless device to the third wireless device based on the state of the first set of one or more communication links and based on the state of a second set of one or more communication links between the first wireless device and the third wireless device, wherein the roaming includes transmitting user data to the third wireless device via the second set of one or more communication links using a second subset of the plurality of user data context parameters corresponding to a second index assigned to the third wireless device; and communicate with the third wireless device via the second set of one or more communication links based on roaming from the second wireless device to the third wireless device using the second subset of the plurality of user data context parameters.

[0133] Clause 2: The first wireless device according to Clause 1, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: transmit or receive packets via one or more communication links using a second subset of the plurality of user data context parameters, wherein the user data context parameters include at least one of an encryption key, PN, SN, or BA associated with the second index assigned to the third wireless device.

[0134] Clause 3: A first wireless device according to any one of Clauses 1 to 2, wherein the processing system is further configured to cause the first wireless device to: obtain indications of the plurality of user data context parameters that are segmented into two or more subsets associated with corresponding indexes, each subset including a plurality of values ​​associated with the corresponding index.

[0135] Clause 4: A first wireless device according to any one of Clauses 1 to 3, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: transmit or receive, via a second set of one or more communication links, a message containing a PN field associated with a second index assigned to the third wireless device, wherein a first number of bits in the PN field indicates the second index, and a second number of bits in the PN field indicates a PN within a PN segment associated with the second index.

[0136] Clause 5: The first wireless device according to Clause 4, wherein: the PN field is 48 bits long; the 8 most significant bits of the PN field indicate the second index; and the remaining 40 bits of the PN field indicate the PN within the PN segment associated with the second index.

[0137] Clause 6: A first wireless device according to any one of Clauses 1 to 5, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: transmit or receive, via a second set of one or more communication links, a frame containing a PN associated with a second subset of the plurality of user data context parameters and a separate field indicating a second index assigned to the third wireless device.

[0138] Clause 7: A first wireless device according to any one of Clauses 1 to 6, wherein the first wireless device includes a non-AP MLD, a STA attached to the non-AP MLD, or a non-MLD non-AP STA; the second wireless device includes a first non-MLD AP or a first AP MLD; and the third wireless device includes a second non-MLD AP or a second AP MLD.

[0139] Clause 8: The first wireless device as described in Clause 7, wherein the first AP includes the serving AP of the STA; and the second AP includes a candidate or target AP to which the STA is roaming.

[0140] Clause 9: The first wireless device according to Clause 8, wherein, in order to communicate with the second wireless device, the processing system is configured to cause the first wireless device to: send or receive one or more packets via the first set of one or more communication links, the one or more packets including a PN associated with the first index of a PN segment currently used for communication between the serving AP and the STA.

[0141] Clause 10: A first wireless device according to any one of Clauses 8 to 9, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: transmit or receive one or more packets via a second set of one or more communication links, the one or more packets comprising a PN within a PN segment associated with a second index assigned to the candidate or target AP.

[0142] Clause 11: A first wireless device according to any one of Clauses 8 to 10, wherein each candidate or target AP of the STA is assigned a different subset of user data context parameters from the plurality of user data context parameters.

[0143] Clause 12: A first wireless device according to any one of Clauses 1 to 11, wherein the first subset of the plurality of user data context parameters includes a segment of a PN capable of being used for communication between the second wireless device and the first wireless device.

[0144] Clause 13: A first wireless device pursuant to any one of Clauses 1 to 12, wherein the second subset of the plurality of user data context parameters is not used until the first wireless device roams from the second wireless device to the third wireless device.

[0145] Clause 14: A first wireless device according to any one of Clauses 1 to 13, wherein, in order to roam from the second wireless device to the third wireless device, the processing system is configured to cause the first wireless device to: establish a connection with the third wireless device without performing a reassociation frame exchange with the third wireless device.

[0146] Clause 15: A first wireless device according to any one of Clauses 1 to 14, wherein the second index is assigned to the third wireless device according to the first index assigned to the second wireless device serving the first wireless device.

[0147] Clause 16: A first wireless device according to any one of Clauses 1 to 15, wherein the processing system is further configured to cause the first wireless device to: communicate with the third wireless device via a second set of one or more communication links, based on roaming from the second wireless device to the third wireless device, using a second subset of the plurality of user data context parameters.

[0148] Clause 17: A first wireless device according to any one of Clauses 1 to 16, wherein the processing system is further configured to cause the first wireless device to: receive an indication that a third index corresponding to a third subset of the plurality of user data context parameters has been reassigned to a second wireless device previously serving the first wireless device.

[0149] Clause 18: The first wireless device as described in Clause 17, wherein the value of the third index is a function of the second index associated with the third wireless device now serving the first wireless device.

[0150] Clause 19: A first wireless device according to any one of Clauses 1 to 18, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: transmit one or more packets to the third wireless device via a second set of one or more communication links in association with determining a threshold amount of time elapsed relative to a first set of one or more communication links.

[0151] Clause 20: A first wireless device according to any one of Clauses 1 to 19, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: perform active user data exchange with a target AP of the third wireless device after the SN for the third wireless device is set to a predetermined value higher than the current SN, wherein the active user data exchange is performed using a PN segment associated with the second index assigned to the third wireless device.

[0152] Clause 21: A first wireless device according to any one of Clauses 1 to 20, wherein, for roaming, the processing system is configured to cause the first wireless device to: transmit a first set of packets using a first set of SNs associated with the first index assigned to the second wireless device; and transmit a second set of packets using a second set of SNs associated with the second index assigned to the third wireless device, wherein the first set of SNs and the second set of SNs are offset.

[0153] Clause 22: A first wireless device according to any one of Clauses 1 to 21, wherein, in order to communicate with the second wireless device, the processing system is configured to cause the first wireless device to: receive, via a first set of one or more communication links, a link recommendation message indicating one or more candidate APs for the first wireless device, wherein each of the one or more candidate APs is assigned a different PN index for the plurality of user data context parameters.

[0154] Clause 23: A first wireless device according to any one of Clauses 1 to 22, wherein, in order to communicate with the third wireless device, the processing system is configured to cause the first wireless device to: send an ML add link request to the third wireless device via a second set of one or more communication links using one or more PN values ​​within a second subset of the plurality of user data context parameters assigned to the third wireless device.

[0155] Clause 24: A first wireless device according to any one of Clauses 1 to 23, wherein, in order to communicate with the third wireless device, the processing system is configured to cause the first wireless device to: receive an ML Add Link Response from the third wireless device via a second set of one or more communication links, the ML Add Link Response indicating a set of encryption keys to be used for communicating with a target AP of the third wireless device.

[0156] Clause 25: A third wireless device comprising: a processing system including processor circuitry and memory circuitry storing code, the processing system being configured to cause the third wireless device to: obtain an indication of a second index assigned to the third wireless device, the second index corresponding to a second subset of a plurality of user data context parameters capable of being used for communication with a first wireless device; receive user data via a second set of one or more communication links between the third wireless device and a first wireless device roaming from a second wireless device to the third wireless device, the user data indicating a second subset of the plurality of user data context parameters corresponding to the second index assigned to the third wireless device, wherein a first subset of the plurality of user data context parameters corresponds to a first index assigned to the first wireless device from which it is roaming; and, based on the user data received from the first wireless device roaming from the second wireless device to the third wireless device, communicate with the first wireless device via the second set of one or more communication links using the second subset of the plurality of user data context parameters corresponding to the second index assigned to the third wireless device.

[0157] Clause 26: The third wireless device according to Clause 25, wherein the processing system is further configured to cause the third wireless device to: instantiate a corresponding 48-bit PN counter for each AP associated with the first wireless device, wherein the corresponding 48-bit PN counter is initialized based on a first PN segment currently used for communicating with the first wireless device.

[0158] Clause 27: A third wireless device as described in Clause 26, wherein the processing system is further configured to cause the third wireless device to perform an anti-replay PN check using the corresponding 48-bit PN counter associated with the AP of the third wireless device that receives the user data from the first wireless device.

[0159] Clause 28: A third wireless device according to any one of Clauses 25 to 27, wherein, in order to receive the user data, the processing system is configured to cause the third wireless device to: receive, via the second set of one or more communication links, a frame containing a PN associated with a second subset of the plurality of user data context parameters and a separate field indicating a second index assigned to the third wireless device; and perform a replay check by combining the PN with the second index.

[0160] Clause 29: A third wireless device according to any one of Clauses 25 to 28, wherein the processing system is further configured to cause the third wireless device to perform a key reconstruction process between the first wireless device and the third wireless device based on the number of available PN values ​​in the second subset of the plurality of user data context parameters, the number of remaining PN segments or subsets in the plurality of user data context parameters, or both.

[0161] Clause 30: A third wireless device according to any one of Clauses 25 to 29, wherein the processing system is further configured to cause the third wireless device to: transmit or receive one or more packets via a gateway between the second wireless device and the third wireless device before receiving the user data from the first wireless device via the second set of one or more communication links between the first wireless device and the third wireless device.

[0162] Clause 31: A third wireless device according to any one of Clauses 25 to 30, wherein the processing system is further configured to cause the third wireless device to: send a path switching frame via a gateway associated with switching the data path of the first wireless device from the second wireless device to the third wireless device.

[0163] Clause 32: A third wireless device according to any one of Clauses 25 to 31, wherein the processing system is further configured to cause the third wireless device to: receive from the centralized controller or serving AP of the first wireless device one or more frames, elements or fields indicating at least one of a security key, PN index or SN offset for the first wireless device, wherein communication with the first wireless device via the second set of one or more communication links is based on the one or more frames, elements or fields.

[0164] Clause 33: A third wireless device as described in Clause 32, wherein the security key for the first wireless device is securely supplied by the centralized controller.

[0165] Clause 34: A third wireless device according to any one of Clauses 25 to 33, wherein the processing system is further configured to cause the third wireless device to: send to a set of adjacent APs attached to the SMD MLD one or more frames, elements or fields indicating at least one of a security key, PN index or SN offset for the first wireless device.

[0166] Clause 35: A third wireless device according to any one of Clauses 25 to 34, wherein the processing system is further configured to cause the third wireless device to receive, via a secure backhaul connection between the third wireless device and a centralized controller, a message indicating at least one security key, PN index, or SN offset for the first wireless device, wherein the at least one security key is supplied by the centralized controller.

[0167] Clause 36: A third wireless device according to any one of Clauses 25 to 35, wherein the processing system is further configured to cause the third wireless device to: send a BAR frame to the first wireless device via the second set of one or more communication links after the first wireless device has successfully transitioned from the second wireless device to the third wireless device.

[0168] Clause 37: A method performed by a first wireless device, the method comprising: a processing system including processor circuitry and memory circuitry storing code, the processing system being configured to cause the first wireless device to: communicate with a second wireless device via a first set of communication links between the first and second wireless devices using a first subset of a plurality of user data context parameters corresponding to a first index assigned to the second wireless device; roam from the second wireless device to the third wireless device based on the state of the first set of one or more communication links and based on the state of a second set of one or more communication links between the first and third wireless devices, wherein the roaming includes transmitting user data to the third wireless device via the second set of one or more communication links using a second subset of the plurality of user data context parameters corresponding to a second index assigned to the third wireless device; and communicate with the third wireless device via the second set of one or more communication links based on roaming from the second wireless device to the third wireless device using the second subset of the plurality of user data context parameters.

[0169] Clause 38: The method according to Clause 37, wherein sending or receiving the user data comprises: using a second subset of the plurality of user data context parameters to send or receive packets via one or more communication links, wherein the user data context parameters include at least one of an encryption key, PN, SN, or BA associated with the second index assigned to the third wireless device.

[0170] Clause 39: The method according to any one of Clauses 37 to 38, the method further comprising: obtaining indications of the plurality of user data context parameters that are segmented into two or more subsets associated with corresponding indexes, each subset including a plurality of values ​​associated with the corresponding index.

[0171] Clause 40: The method according to any one of Clauses 37 to 39, wherein sending or receiving the user data comprises: sending or receiving, via the second set of one or more communication links, a message containing a PN field associated with the second index assigned to the third wireless device, wherein a first number of bits in the PN field indicates the second index, and a second number of bits in the PN field indicates a PN within a PN segment associated with the second index.

[0172] Clause 41: The first wireless device according to Clause 40, wherein the PN field is 48 bits long; the 8 most significant bits of the PN field indicate the second index; and the remaining 40 bits of the PN field indicate the PN within the PN segment associated with the second index.

[0173] Clause 42: The method according to any one of Clauses 37 to 41, wherein sending or receiving the user data comprises: sending or receiving, via the second set of one or more communication links, a frame containing a PN associated with a second subset of the plurality of user data context parameters and a separate field indicating a second index assigned to the third wireless device.

[0174] Clause 43: The method according to any one of Clauses 37 to 42, wherein the first wireless device includes a non-AP MLD, a STA attached to the non-AP MLD, or a non-MLD non-AP STA; the second wireless device includes a first non-MLD AP or a first AP MLD; and the third wireless device includes a second non-MLD AP or a second AP MLD.

[0175] Clause 44: The method according to Clause 43, wherein the first AP includes the serving AP of the STA; and the second AP includes the candidate or target AP to which the STA is roaming.

[0176] Clause 45: The method according to Clause 44, wherein communicating with the second wireless device comprises: sending or receiving one or more packets via the first set of one or more communication links, the one or more packets comprising a PN associated with the first index of a PN segment currently used for communication between the serving AP and the STA.

[0177] Clause 46: The method according to any one of Clauses 44 to 45, wherein sending or receiving the user data comprises: sending or receiving one or more packets via the second set of one or more communication links, the one or more packets comprising a PN within a PN segment associated with the second index assigned to the candidate or target AP.

[0178] Clause 47: The method according to any one of Clauses 44 to 46, wherein each candidate or target AP of the STA is assigned a different subset of the user data context parameters from the plurality of user data context parameters.

[0179] Clause 48: The method according to any one of Clauses 37 to 47, wherein the first subset of the plurality of user data context parameters includes a segment of a PN capable of being used for communication between the second wireless device and the first wireless device.

[0180] Clause 49: The method according to any one of Clauses 37 to 48, wherein the second subset of the plurality of user data context parameters is not used until the first wireless device roams from the second wireless device to the third wireless device.

[0181] Clause 50: The method according to any one of Clauses 37 to 49, wherein roaming from the second wireless device to the third wireless device comprises: establishing a connection with the third wireless device without performing a reassociation frame exchange with the third wireless device.

[0182] Clause 51: The method according to any one of Clauses 37 to 50, wherein the second index is assigned to the third wireless device based on the first index assigned to the second wireless device serving the first wireless device.

[0183] Clause 52: The method according to any one of Clauses 37 to 51, the method further comprising: communicating with the third wireless device via one or more communication links using a second subset of the plurality of user data context parameters, based on roaming from the second wireless device to the third wireless device.

[0184] Clause 53: The method according to any one of Clauses 37 to 52, the method further comprising: receiving an indication that a third index corresponding to a third subset of the plurality of user data context parameters has been reassigned to a second wireless device previously serving the first wireless device.

[0185] Clause 54: The method described in Clause 53, wherein the value of the third index is a function of the second index associated with the third wireless device now serving the first wireless device.

[0186] Clause 55: The method according to any one of Clauses 37 to 54, wherein sending or receiving the user data comprises: sending one or more packets to the third wireless device via the second set of one or more communication links in association with determining a threshold amount of time elapsed relative to the last uplink packet transmitted via the first set of one or more communication links.

[0187] Clause 56: The method according to any one of Clauses 37 to 55, wherein sending or receiving the user data comprises: performing an active user data exchange with a target AP of the third wireless device after the SN for the third wireless device is set to a predetermined value higher than the current SN, wherein the active user data exchange is performed using a PN segment associated with the second index assigned to the third wireless device.

[0188] Clause 57: The method according to any one of Clauses 37 to 56, wherein the roaming comprises: transmitting a first set of packets using a first set of SNs associated with the first index assigned to the second wireless device; and transmitting a second set of packets using a second set of SNs associated with the second index assigned to the third wireless device, wherein there is an offset between the first set of SNs and the second set of SNs.

[0189] Clause 58: The method according to any one of Clauses 37 to 57, wherein communicating with the second wireless device comprises: receiving, via the first set of one or more communication links, a link recommendation message indicating one or more candidate APs for the first wireless device, wherein each of the one or more candidate APs is assigned a different PN index for the plurality of user data context parameters.

[0190] Clause 59: The method according to any one of Clauses 37 to 58, wherein communicating with the third wireless device comprises: sending an ML add link request to the third wireless device via the second set of one or more communication links using one or more PN values ​​within a second subset of the plurality of user data context parameters assigned to the third wireless device.

[0191] Clause 60: The method according to any one of Clauses 37 to 59, wherein communicating with the third wireless device comprises: receiving an ML Add Link Response from the third wireless device via a second set of one or more communication links, the ML Add Link Response indicating a set of encryption keys to be used for communicating with a target AP of the third wireless device.

[0192] Clause 61: A method performed by a third wireless device, the method comprising: a processing system including processor circuitry and memory circuitry storing code, the processing system being configured to cause the third wireless device to: obtain an indication of a second index assigned to the third wireless device, the second index corresponding to a second subset of a plurality of user data context parameters capable of being used for communication with a first wireless device; receive user data via a second set of one or more communication links between the third wireless device and a first wireless device roaming from the second wireless device to the third wireless device, the user data indicating the second subset of the plurality of user data context parameters corresponding to the second index assigned to the third wireless device, wherein a first subset of the plurality of user data context parameters corresponds to a first index assigned to the first wireless device from which the second wireless device is roaming; and, based on the user data received from the first wireless device roaming from the second wireless device to the third wireless device, communicate with the first wireless device via the second set of one or more communication links using the second subset of the plurality of user data context parameters corresponding to the second index assigned to the third wireless device.

[0193] Clause 62: The method according to Clause 61 further comprises: instantiating a corresponding 48-bit PN counter for each AP associated with the first wireless device, wherein the corresponding 48-bit PN counter is initialized based on a first PN segment currently used for communicating with the first wireless device.

[0194] Clause 63: The method according to Clause 62 further includes: performing an anti-replay PN check using the corresponding 48-bit PN counter associated with the AP of the third wireless device that receives the user data from the first wireless device.

[0195] Clause 64: The method according to any one of Clauses 61 to 63, wherein receiving the user data comprises: receiving, via the second set of one or more communication links, a frame containing a PN associated with a second subset of the plurality of user data context parameters and a separate field indicating a second index assigned to the third wireless device; and performing a replay check by combining the PN with the second index.

[0196] Clause 65: The method according to any one of Clauses 61 to 64, the method further comprising: performing a key reconstruction process between the first wireless device and the third wireless device based on the number of available PN values ​​in the second subset of the plurality of user data context parameters, the number of remaining PN segments or subsets in the plurality of user data context parameters, or both.

[0197] Clause 66: The method according to any one of Clauses 61 to 65 further comprises: sending or receiving one or more packets via a gateway between the second wireless device and the third wireless device before receiving the user data from the first wireless device via the second set of one or more communication links between the first wireless device and the third wireless device.

[0198] Clause 67: The method according to any one of Clauses 61 to 66, the method further comprising: sending via a gateway a path switching frame associated with switching the data path of the first wireless device from the second wireless device to the third wireless device.

[0199] Clause 68: The method according to any one of Clauses 61 to 67, the method further comprising: receiving from a centralized controller or serving AP of the first wireless device one or more frames, elements or fields indicating at least one of a security key, PN index or SN offset for the first wireless device, wherein communication with the first wireless device via the second set of one or more communication links is based on the one or more frames, elements or fields.

[0200] Clause 69: The method according to Clause 68, wherein the security key for the first wireless device is securely supplied by the centralized controller.

[0201] Clause 70: The method according to any one of Clauses 61 to 69 further comprises: sending to a set of adjacent APs attached to the SMDMLD one or more frames, elements or fields indicating at least one of a security key, PN index or SN offset for the first wireless device.

[0202] Clause 71: The method according to any one of Clauses 61 to 70, further comprising: receiving a message indicating at least one security key, PN index, or SN offset for the first wireless device via a secure backhaul connection between the third wireless device and a centralized controller, wherein the at least one security key is supplied by the centralized controller.

[0203] Clause 72: The method according to any one of Clauses 61 to 71, the method further comprising: after the first wireless device successfully transitions from the second wireless device to the third wireless device, sending a BAR frame to the first wireless device via the second set of one or more communication links.

[0204] As used herein, the term "determine" encompasses a wide variety of actions, and therefore, "determine" can include calculation, computation, processing, derivation, estimation, investigation, searching (such as by searching in a table, database, or other data structure), reasoning, probing, or measurement, among other possibilities. Furthermore, "determine" can include receiving (such as receiving information), accessing (such as accessing data stored in memory), or sending (such as sending information), among other possibilities. Additionally, "determine" can include parsing, selecting, obtaining, choosing, building, and other similar actions.

[0205] As used herein, the phrase “at least one of” or “one or more of” refers to any combination of these items, including a single member. For example, “at least one of a, b, or c” is intended to cover: a, b, c, ab, ac, bc, and abc. As used herein, “or” is intended to be interpreted as inclusive unless otherwise explicitly stated. For example, “a or b” could include only a, only b, or a combination of a and b. Furthermore, as used herein, the phrase referring to “one” element means one or more of such elements that act individually or collectively to perform the stated function. Additionally, “set” refers to one or more items, and “subset” refers to less than the entire set, but not empty.

[0206] As used herein, unless otherwise expressly indicated, “based on” is intended to be interpreted in an inclusive sense. For example, unless otherwise explicitly indicated, “based on” may be used interchangeably with “at least partially based on,” “associated with,” “associated with,” or “according to.” Specifically, unless the phrase in the context means “based on only one” or an equivalent, whether it is “based on one” or “at least partially based on one”, it may be based solely on “one” or based on a combination of “one” and one or more other factors, conditions, or information.

[0207] The various exemplary components, logic units, logic blocks, modules, circuits, operations, and algorithmic processes described in conjunction with the examples disclosed herein can be implemented as electronic hardware, firmware, software, or a combination of hardware, firmware, or software, including the structures disclosed in this specification and their structural equivalents. This interchangeability of hardware, firmware, and software has been generally described in terms of its functionality and exemplified in the various exemplary components, blocks, modules, circuits, and processes described above. Whether this functionality is implemented in hardware, firmware, or software depends on the specific application and the design constraints imposed on the overall system.

[0208] Various modifications to the examples described herein will be apparent to those skilled in the art, and the general principles defined herein may be applied to other examples without departing from the spirit or scope of this disclosure. Therefore, the claims are not intended to be limited to the examples shown herein, but are to be granted the widest scope consistent with this disclosure, the principles disclosed herein, and the novel features.

[0209] Additionally, the various features described in this specification in the context of individual examples may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple examples. Thus, although features may be described above as functioning in a particular combination, and even initially claimed in this way, one or more features from the claimed combination may be removed from the combination in some embodiments, and the claimed combination may be for sub-combinations or variations thereof.

[0210] Similarly, although operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring such operations to be performed in the specific order shown or in sequential order, or to perform all illustrated operations to achieve the desired result. Furthermore, the drawings may schematically depict one or more example processes in the form of flowcharts or diagrams. However, other operations not depicted may be incorporated into the schematically illustrated example processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. In some environments, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the examples described above should not be construed as requiring such separation in all examples, but rather should be understood as meaning that the described program components and systems can generally be integrated together in a single software product or encapsulated in multiple software products.

Claims

1. A first wireless device, the first wireless device comprising: The processing system, including processor circuitry and memory circuitry for storing code, is configured to cause the first wireless device to: Using a first subset of multiple user data context parameters corresponding to a first index assigned to the second wireless device, the second wireless device is communicated via a first set of one or more communication links between the first wireless device and the second wireless device. Roaming from the second wireless device to the third wireless device is based at least in part on the state of the first set of one or more communication links and at least in part on the state of the second set of one or more communication links between the first wireless device and the third wireless device, wherein the roaming includes sending user data to the third wireless device via the second set of one or more communication links using a second subset of the plurality of user data context parameters corresponding to a second index assigned to the third wireless device; as well as The third wireless device communicates with the second set of one or more communication links, at least in part, based on a second subset of the plurality of user data context parameters, roaming from the second wireless device to the third wireless device.

2. The first wireless device according to claim 1, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: Using a second subset of the plurality of user data context parameters to send or receive packets via one or more communication links, wherein the user data context parameters include at least one of an encryption key, a packet number, a sequence number, or a block acknowledgment associated with the second index assigned to the third wireless device.

3. The first wireless device according to claim 1, wherein the processing system is further configured to cause the first wireless device to: Obtain indications for the plurality of user data context parameters that are divided into two or more subsets associated with corresponding indexes, each subset including a plurality of values ​​associated with the corresponding index.

4. The first wireless device of claim 1, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: The second set of communication links transmits or receives a message containing a packet number field associated with the second index assigned to the third wireless device, wherein a first number of bits in the packet number field indicates the second index, and a second number of bits in the packet number field indicates a packet number within a packet number segment associated with the second index.

5. The first wireless device according to claim 4, wherein: The group number field is 48 bits long; The eight most significant bits of the group number field indicate the second index; and The remaining 40 bits of the group number field indicate the group number within the group number segment associated with the second index.

6. The first wireless device of claim 1, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: The second set of communication links transmits or receives frames containing a packet number associated with a second subset of the plurality of user data context parameters and a separate field indicating the second index assigned to the third wireless device.

7. The first wireless device according to claim 1, wherein: The first wireless device includes a non-access point (AP) multi-link device (MLD), a station (STA) attached to the non-AP MLD, or a non-MLD non-AP STA; The second wireless device includes a first non-MLD AP or a first AP MLD; and The third wireless device includes a second non-MLD AP or a second AP MLD.

8. The first wireless device according to claim 7, wherein: The first AP includes the serving AP of the STA; and The second AP includes the candidate or target AP that the STA is roaming to.

9. The first wireless device of claim 8, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: The second set of communication links sends or receives one or more packets, the one or more packets including packet numbers within a packet number range associated with the second index assigned to the candidate or target AP.

10. The first wireless device of claim 8, wherein each candidate or target AP of the STA is assigned a different subset of user data context parameters from the plurality of user data context parameters.

11. The first wireless device of claim 1, wherein the processing system is further configured to cause the first wireless device to: An indication is received that a third index corresponding to a third subset of the plurality of user data context parameters has been reassigned to a second wireless device that previously served the first wireless device.

12. The first wireless device of claim 1, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: One or more packets are sent to the third wireless device via one or more communication links in association with determining that a threshold amount of time has elapsed relative to the last uplink packet transmitted via the first set of one or more communication links.

13. The first wireless device of claim 1, wherein, in order to transmit or receive the user data, the processing system is configured to cause the first wireless device to: After the serial number of the third wireless device is set to a predetermined value higher than the current serial number, an active user data exchange is performed with the target access point (AP) of the third wireless device, wherein the active user data exchange is performed using a packet number segment associated with the second index assigned to the third wireless device.

14. The first wireless device of claim 1, wherein, for the purpose of roaming, the processing system is configured to cause the first wireless device to: A first set of packets is sent using a first set of sequence numbers associated with the first index assigned to the second wireless device; and The second set of packets is sent using a second set of sequence numbers associated with the second index assigned to the third wireless device, wherein the first set of sequence numbers is offset from the second set of sequence numbers.

15. The first wireless device of claim 1, wherein, in order to communicate with the second wireless device, the processing system is configured to cause the first wireless device to: The first set of communication links receives a link recommendation message indicating one or more candidate access points (APs) for the first wireless device, wherein each of the one or more candidate APs is assigned a different group number index for the plurality of user data context parameters.

16. The first wireless device of claim 1, wherein, in order to communicate with the third wireless device, the processing system is configured to cause the first wireless device to: A multi-link add link request is sent to the third wireless device via the second set of one or more communication links using one or more packet number values ​​from the second subset of the plurality of user data context parameters assigned to the third wireless device.

17. The first wireless device of claim 1, wherein, in order to communicate with the third wireless device, the processing system is configured to cause the first wireless device to: The third wireless device receives a multilink add link response from the second set of one or more communication links, the multilink add link response indicating a set of encryption keys to be used for communication with the target access point (AP) of the third wireless device.

18. A third wireless device, the third wireless device comprising: A processing system, comprising processor circuitry and memory circuitry for storing code, is configured to enable the third wireless device to: Obtain an indication of a second index assigned to the third wireless device, the second index corresponding to a second subset of a plurality of user data context parameters that can be used for communication with the first wireless device; User data is received via a second set of one or more communication links between the third wireless device and the first wireless device roaming from the second wireless device to the third wireless device. The user data indicates a second subset of a plurality of user data context parameters corresponding to a second index assigned to the third wireless device, wherein a first subset of the plurality of user data context parameters corresponds to a first index assigned to the first wireless device from which the second wireless device is roaming. as well as The user data is received from the first wireless device roaming from the second wireless device to the third wireless device, and the user communicates with the first wireless device via a second set of one or more communication links using a second subset of the plurality of user data context parameters corresponding to the second index assigned to the third wireless device.

19. The third wireless device of claim 18, wherein the processing system is further configured to cause the third wireless device to: A corresponding 48-bit packet number counter is instantiated for each access point (AP) associated with the first wireless device, wherein the corresponding 48-bit packet number counter is initialized based on a first packet number segment currently used for communicating with the first wireless device.

20. The third wireless device of claim 19, wherein the processing system is further configured to cause the third wireless device to: Anti-replay packet number checking is performed using the corresponding 48-bit packet number counter associated with the AP of the third wireless device that receives the user data from the first wireless device.

21. The third wireless device of claim 18, wherein, in order to receive the user data, the processing system is configured to cause the third wireless device to: Receive, via one or more communication links, a frame containing a packet number associated with a second subset of the plurality of user data context parameters and a separate field indicating a second index assigned to the third wireless device; and A replay check is performed by combining the group number with the second index.

22. The third wireless device of claim 18, wherein the processing system is further configured to cause the third wireless device to: The key reconstruction process is performed between the first wireless device and the third wireless device based at least in part on the number of available block number values ​​in the second subset of the plurality of user data context parameters, the number of remaining block number segments or subsets in the plurality of user data context parameters, or both.

23. The third wireless device of claim 18, wherein the processing system is further configured to cause the third wireless device to: Before receiving the user data from the first wireless device via the second set of one or more communication links between the first wireless device and the third wireless device, one or more packets are sent or received via a gateway between the second wireless device and the third wireless device.

24. The third wireless device of claim 18, wherein the processing system is further configured to cause the third wireless device to: A path switching frame associated with switching the data path of the first wireless device from the second wireless device to the third wireless device is sent via the gateway.

25. The third wireless device of claim 18, wherein the processing system is further configured to cause the third wireless device to: Receive one or more frames, elements, or fields from the centralized controller or service access point (AP) of the first wireless device that indicate at least one of a security key, a packet number index, or a sequence number offset for the first wireless device, wherein communication with the first wireless device via the second set of one or more communication links is based at least in part on the one or more frames, elements, or fields.

26. The third wireless device of claim 18, wherein the processing system is further configured to cause the third wireless device to: Send one or more frames, elements, or fields to a set of adjacent access points (APs) attached to the SMD multilink device, indicating at least one of a security key, packet number index, or sequence number offset for the first wireless device.

27. The third wireless device of claim 18, wherein the processing system is further configured to cause the third wireless device to: The system receives a message indicating at least one security key, block number index, or sequence number offset for the first wireless device via a secure backhaul connection between the third wireless device and the centralized controller, wherein the at least one security key is supplied by the centralized controller.

28. The third wireless device of claim 18, wherein the processing system is further configured to cause the third wireless device to: After the first wireless device successfully transitions from the second wireless device to the third wireless device, a block acknowledgment request frame is sent to the first wireless device via the second set of one or more communication links.

29. A method for wireless communication by a first wireless device, the method comprising: Using a first subset of multiple user data context parameters corresponding to a first index assigned to the second wireless device, the second wireless device is communicated via a first set of one or more communication links between the first wireless device and the second wireless device. Roaming from the second wireless device to the third wireless device is based at least in part on the state of the first set of one or more communication links and at least in part on the state of the second set of one or more communication links between the first wireless device and the third wireless device, wherein the roaming includes sending user data to the third wireless device via the second set of one or more communication links using a second subset of the plurality of user data context parameters corresponding to a second index assigned to the third wireless device; as well as The third wireless device communicates with the second set of one or more communication links, at least in part, based on a second subset of the plurality of user data context parameters, roaming from the second wireless device to the third wireless device.

30. A method for wireless communication by a third wireless device, the method comprising: Obtain an indication of a second index assigned to the third wireless device, the second index corresponding to a second subset of a plurality of user data context parameters that can be used for communication with the first wireless device; User data is received via a second set of one or more communication links between the third wireless device and the first wireless device roaming from the second wireless device to the third wireless device. The user data indicates a second subset of a plurality of user data context parameters corresponding to a second index assigned to the third wireless device, wherein a first subset of the plurality of user data context parameters corresponds to a first index assigned to the first wireless device from which the second wireless device is roaming. as well as The user data is received from the first wireless device roaming from the second wireless device to the third wireless device, and the user communicates with the first wireless device via a second set of one or more communication links using a second subset of the plurality of user data context parameters corresponding to the second index assigned to the third wireless device.

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