Patent Description:
Wireless communication systems are rapidly growing in usage. Further, wireless communication technology has evolved from voice-only communications to also include the transmission of data, such as Internet and multimedia content. A popular short/intermediate range wireless communication standard is wireless local area network (WLAN). Most modern WLANs are based on the IEEE <NUM> standard (and/or <NUM>, for short) and are marketed under the Wi-Fi brand name. WLAN networks link one or more devices to a wireless access point, which in turn provides connectivity to the wider area Internet.

In <NUM> systems, devices that wirelessly connect to each other are referred to as "stations", "mobile stations", "user devices" or STA or UE for short. Wireless stations can be either wireless access points or wireless clients (and/or mobile stations). Access points (APs), which are also referred to as wireless routers, act as base stations for the wireless network. APs transmit and receive radio frequency signals for communication with wireless client devices. APs can also typically couple to the Internet in a wired fashion. Wireless clients operating on an <NUM> network can be any of various devices such as laptops, tablet devices, smart phones, or fixed devices such as desktop computers. Wireless client devices are referred to herein as user equipment (and/or UE for short). Some wireless client devices are also collectively referred to herein as mobile devices or mobile stations (although, as noted above, wireless client devices overall may be stationary devices as well).

Mobile electronic devices may take the form of smart phones or tablets that a user typically carries. Wearable devices (also referred to as accessory devices) are a newer form of mobile electronic device, one example being smart watches. Additionally, low-cost low-complexity wireless devices intended for stationary or nomadic deployment are also proliferating as part of the developing "Internet of Things". In other words, there is an increasingly wide range of desired device complexities, capabilities, traffic patterns, and other characteristics.

<NPL>, discloses various discussions on AP MLD Beaconing and Discovery.

<NPL>, discloses various discussions on beacon protection.

<NPL>, discloses various discussions on specification frameworks for TGbe.

Embodiments described herein relate to systems, methods, and mechanisms for robust discovery of a new access point (AP) in AP MLD, robust link addition to an AP MLD association, AP beaconing modes when the AP is added or deleted to/from an AP MLD, and robust BSS transition management (BTM) signaling to steer a non-AP MLD to a best AP MLD and to most suitable APs, as well as privacy improvements for associated non-AP MLD. Note that in embodiments described herein "robust" refers to wireless communication that is configured to withstand technical faults, signal disturbances, and security threats.

The invention provides a method according to claim <NUM>, a wireless station according to claim <NUM> and a computer program product according to claim <NUM>.

A better understanding of the present subject matter can be obtained when the following detailed description of the embodiments is considered in conjunction with the following drawings.

While the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to be limiting to the particular form disclosed, but on the contrary, the intention is to cover all modifications falling within the scope of the subject matter as defined by the appended claims.

<FIG> illustrates an exemplary (and simplified) wireless communication system in which aspects of this disclosure may be implemented. It is noted that the system of <FIG> is merely one example of a possible system, and embodiments of this disclosure may be implemented in any of various systems, as desired.

As shown, the exemplary wireless communication system includes a ("first") wireless device <NUM> in communication with another ("second") wireless device. The first wireless device <NUM> and the second wireless device <NUM> may communicate wirelessly using any of a variety of wireless communication techniques, potentially including ranging wireless communication techniques.

As one possibility, the first wireless device <NUM> and the second wireless device <NUM> may perform ranging using wireless local area networking (WLAN) communication technology (e.g., IEEE <NUM> / Wi-Fi based communication) and/or techniques based on WLAN wireless communication. One or both of the wireless device <NUM> and the wireless device <NUM> may also be capable of communicating via one or more additional wireless communication protocols, such as any of Bluetooth (BT), Bluetooth Low Energy (BLE), near field communication (NFC), GSM, UMTS (WCDMA, TDSCDMA), LTE, LTE-Advanced (LTE-A), NR, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-MAX, GPS, etc..

The wireless devices <NUM> and <NUM> may be any of a variety of types of wireless device. As one possibility, one or more of the wireless devices <NUM> and/or <NUM> may be a substantially portable wireless user equipment (UE) device, such as a smart phone, handheld device, a wearable device such as a smart watch, a tablet, a motor vehicle, or virtually any type of wireless device. As another possibility, one or more of the wireless devices <NUM> and/or <NUM> may be a substantially stationary device, such as a set top box, media player (e.g., an audio or audiovisual device), gaming console, desktop computer, appliance, door, access point, base station, or any of a variety of other types of device.

Each of the wireless devices <NUM> and <NUM> may include wireless communication circuitry configured to facilitate the performance of wireless communication, which may include various digital and/or analog radio frequency (RF) components, a processor that is configured to execute program instructions stored in memory, a programmable hardware element such as a field-programmable gate array (FPGA), and/or any of various other components. The wireless device <NUM> and/or the wireless device <NUM> may perform any of the method embodiments described herein, or any portion of any of the method embodiments described herein, using any or all of such components.

Each of the wireless devices <NUM> and <NUM> may include one or more antennas for communicating using one or more wireless communication protocols. In some cases, one or more parts of a receive and/or transmit chain may be shared between multiple wireless communication standards; for example, a device might be configured to communicate using either of Bluetooth or Wi-Fi using partially or entirely shared wireless communication circuitry (e.g., using a shared radio or at least shared radio components). The shared communication circuitry may include a single antenna, or may include multiple antennas (e.g., for MIMO) for performing wireless communications. Alternatively, a device may include separate transmit and/or receive chains (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As a further possibility, a device may include one or more radios or radio components which are shared between multiple wireless communication protocols, and one or more radios or radio components which are used exclusively by a single wireless communication protocol. For example, a device might include a shared radio for communicating using one or more of LTE, CDMA2000 1xRTT, GSM, and/or <NUM> NR, and separate radios for communicating using each of Wi-Fi and Bluetooth.

As previously noted, aspects of this disclosure may be implemented in conjunction with the wireless communication system of <FIG>. For example, a wireless device (e.g., either of wireless devices <NUM> or <NUM>) may be configured to perform methods for robust discovery of a new access point (AP) in AP MLD, robust link addition to an AP MLD association, AP beaconing modes when the AP is added or deleted to/from an AP MLD, and robust BSS transition management (BTM) signaling to steer a non-AP MLD to a best AP MLD and to most suitable APs, as well as privacy improvements for associated non-AP MLD.

<FIG> illustrates an exemplary wireless device <NUM> (e.g., corresponding to wireless devices <NUM> and/or <NUM>) that may be configured for use in conjunction with various aspects of the present disclosure. The device <NUM> may be any of a variety of types of device and may be configured to perform any of a variety of types of functionality. The device <NUM> may be a substantially portable device or may be a substantially stationary device, potentially including any of a variety of types of device. The device <NUM> may be configured to perform one or more ranging wireless communication techniques or features, such as any of the techniques or features illustrated and/or described subsequently herein with respect to any or all of the Figures.

As shown, the device <NUM> may include a processing element <NUM>. The processing element may include or be coupled to one or more memory elements. For example, the device <NUM> may include one or more memory media (e.g., memory <NUM>), which may include any of a variety of types of memory and may serve any of a variety of functions. For example, memory <NUM> could be RAM serving as a system memory for processing element <NUM>. Other types and functions are also possible.

Additionally, the device <NUM> may include wireless communication circuitry <NUM>. The wireless communication circuitry may include any of a variety of communication elements (e.g., antenna for wireless communication, analog and/or digital communication circuitry/controllers, etc.) and may enable the device to wirelessly communicate using one or more wireless communication protocols.

Note that in some cases, the wireless communication circuitry <NUM> may include its own processing element (e.g., a baseband processor), e.g., in addition to the processing element <NUM>. For example, the processing element <NUM> may be an 'application processor' whose primary function may be to support application layer operations in the device <NUM>, while the wireless communication circuitry <NUM> may be a 'baseband processor' whose primary function may be to support baseband layer operations (e.g., to facilitate wireless communication between the device <NUM> and other devices) in the device <NUM>. In other words, in some cases the device <NUM> may include multiple processing elements (e.g., may be a multi-processor device). Other configurations (e.g., instead of or in addition to an application processor / baseband processor configuration) utilizing a multi-processor architecture are also possible.

The device <NUM> may additionally include any of a variety of other components (not shown) for implementing device functionality, depending on the intended functionality of the device <NUM>, which may include further processing and/or memory elements (e.g., audio processing circuitry), one or more power supply elements (which may rely on battery power and/or an external power source) user interface elements (e.g., display, speaker, microphone, camera, keyboard, mouse, touchscreen, etc.), and/or any of various other components.

The components of the device <NUM>, such as processing element <NUM>, memory <NUM>, and wireless communication circuitry <NUM>, may be operatively coupled via one or more interconnection interfaces, which may include any of a variety of types of interface, possibly including a combination of multiple types of interface. As one example, a USB high-speed inter-chip (HSIC) interface may be provided for inter-chip communications between processing elements. Alternatively (and/or in addition), a universal asynchronous receiver transmitter (UART) interface, a serial peripheral interface (SPI), inter-integrated circuit (I2C), system management bus (SMBus), and/or any of a variety of other communication interfaces may be used for communications between various device components. Other types of interfaces (e.g., intra-chip interfaces for communication within processing element <NUM>, peripheral interfaces for communication with peripheral components within or external to device <NUM>, etc.) may also be provided as part of device <NUM>.

<FIG> illustrates an example WLAN system according to some embodiments. As shown, the exemplary WLAN system includes a plurality of wireless client stations or devices, or user equipment (UEs), <NUM> that are configured to communicate over a wireless communication channel <NUM> with an Access Point (AP) <NUM>. The AP <NUM> may be a Wi-Fi access point. The AP <NUM> may communicate via a wired and/or a wireless communication channel <NUM> with one or more other electronic devices (not shown) and/or another network <NUM>, such as the Internet. Additional electronic devices, such as the remote device <NUM>, may communicate with components of the WLAN system via the network <NUM>. For example, the remote device <NUM> may be another wireless client station. The WLAN system may be configured to operate according to any of various communications standards, such as the various IEEE <NUM> standards. In some embodiments, at least one wireless device <NUM> is configured to communicate directly with one or more neighboring mobile devices, without use of the access point <NUM>.

Further, in some embodiments, a wireless device <NUM> (which may be an exemplary implementation of device <NUM>) may be configured to perform methods for robust discovery of a new access point (AP) in AP MLD, robust link addition to an AP MLD association, AP beaconing modes when the AP is added or deleted to/from an AP MLD, and robust BSS transition management (BTM) signaling to steer a non-AP MLD to a best AP MLD and to most suitable APs, as well as privacy improvements for associated non-AP MLD.

<FIG> illustrates an exemplary block diagram of an access point (AP) <NUM>, which may be one possible exemplary implementation of the device <NUM> illustrated in <FIG>. It is noted that the block diagram of the AP of <FIG> is only one example of a possible system. As shown, the AP <NUM> may include processor(s) <NUM> which may execute program instructions for the AP <NUM>. The processor(s) <NUM> may also be coupled (directly or indirectly) to memory management unit (MMU) <NUM>, which may be configured to receive addresses from the processor(s) <NUM> and to translate those addresses to locations in memory (e.g., memory <NUM> and read only memory (ROM) <NUM>) or to other circuits or devices.

The AP <NUM> may include at least one network port <NUM>. The network port <NUM> may be configured to couple to a wired network and provide a plurality of devices, such as mobile devices <NUM>, access to the Internet. For example, the network port <NUM> (and/or an additional network port) may be configured to couple to a local network, such as a home network or an enterprise network. For example, port <NUM> may be an Ethernet port. The local network may provide connectivity to additional networks, such as the Internet.

The AP <NUM> may include at least one antenna <NUM>, which may be configured to operate as a wireless transceiver and may be further configured to communicate with mobile device <NUM> via wireless communication circuitry <NUM>. The antenna <NUM> communicates with the wireless communication circuitry <NUM> via communication chain <NUM>. Communication chain <NUM> may include one or more receive chains, one or more transmit chains or both. The wireless communication circuitry <NUM> may be configured to communicate via Wi-Fi or WLAN, e.g., <NUM>. The wireless communication circuitry <NUM> may also, or alternatively, be configured to communicate via various other wireless communication technologies, including, but not limited to, Long-Term Evolution (LTE), LTE Advanced (LTE-A), Global System for Mobile (GSM), Wideband Code Division Multiple Access (WCDMA), CDMA2000, etc., for example when the AP is co-located with a base station in case of a small cell, or in other instances when it may be desirable for the AP <NUM> to communicate via various different wireless communication technologies.

Further, in some embodiments, as further described below, AP <NUM> may be configured to perform methods for robust discovery of a new access point (AP) in AP MLD, robust link addition to an AP MLD association, AP beaconing modes when the AP is added or deleted to/from an AP MLD, and robust BSS transition management (BTM) signaling to steer a non-AP MLD to a best AP MLD and to most suitable APs, as well as privacy improvements for associated non-AP MLD.

<FIG> illustrates an example simplified block diagram of a client station <NUM>, which may be one possible exemplary implementation of the device <NUM> illustrated in <FIG>. According to embodiments, client station <NUM> may be a user equipment (UE) device, a mobile device or mobile station, and/or a wireless device or wireless station. As shown, the client station <NUM> may include a system on chip (SOC) <NUM>, which may include portions for various purposes. The SOC <NUM> may be coupled to various other circuits of the client station <NUM>. For example, the client station <NUM> may include various types of memory (e.g., including NAND flash <NUM>), a connector interface (I/F) (and/or dock) <NUM> (e.g., for coupling to a computer system, dock, charging station, etc.), the display <NUM>, cellular communication circuitry (e.g., cellular radio) <NUM> such as for <NUM> NR, LTE, GSM, etc., and short to medium range wireless communication circuitry (e.g., Bluetooth™/WLAN radio) <NUM> (e.g., Bluetooth™ and WLAN circuitry). The client station <NUM> may further include one or more smart cards <NUM> that incorporate SIM (Subscriber Identity Module) functionality, such as one or more UICC(s) (Universal Integrated Circuit Card(s)). The cellular communication circuitry <NUM> may couple to one or more antennas, such as antennas <NUM> and <NUM> as shown. The short to medium range wireless communication circuitry <NUM> may also couple to one or more antennas, such as antennas <NUM> and <NUM> as shown. Alternatively, the short to medium range wireless communication circuitry <NUM> may couple to the antennas <NUM> and <NUM> in addition to, or instead of, coupling to the antennas <NUM> and <NUM>. The short to medium range wireless communication circuitry <NUM> may include multiple receive chains and/or multiple transmit chains for receiving and/or transmitting multiple spatial streams, such as in a multiple-input multiple output (MIMO) configuration. Some or all components of the short to medium range wireless communication circuitry <NUM> and/or the cellular communication circuitry <NUM> may be used for ranging communications, e.g., using WLAN, Bluetooth, and/or cellular communications.

As shown, the SOC <NUM> may include processor(s) <NUM>, which may execute program instructions for the client station <NUM> and display circuitry <NUM>, which may perform graphics processing and provide display signals to the display <NUM>. The SOC <NUM> may also include motion sensing circuitry <NUM> which may detect motion of the client station <NUM>, for example using a gyroscope, accelerometer, and/or any of various other motion sensing components. The processor(s) <NUM> may also be coupled to memory management unit (MMU) <NUM>, which may be configured to receive addresses from the processor(s) <NUM> and translate those addresses to locations in memory (e.g., memory <NUM>, read only memory (ROM) <NUM>, NAND flash memory <NUM>) and/or to other circuits or devices, such as the display circuitry <NUM>, cellular communication circuitry <NUM>, short range wireless communication circuitry <NUM>, connector interface (I/F) <NUM>, and/or display <NUM>. The MMU <NUM> may be configured to perform memory protection and page table translation or set up. In some embodiments, the MMU <NUM> may be included as a portion of the processor(s) <NUM>.

As noted above, the client station <NUM> may be configured to communicate wirelessly directly with one or more neighboring client stations. The client station <NUM> may be configured to communicate according to a WLAN RAT for communication in a WLAN network, such as that shown in <FIG> or for ranging as shown in <FIG>. Further, in some embodiments,.

As described herein, the client station <NUM> may include hardware and software components for implementing the features described herein. For example, the processor <NUM> of the client station <NUM> may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (and/or in addition), processor <NUM> may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (and/or in addition) the processor <NUM> of the UE <NUM>, in conjunction with one or more of the other components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>,<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be configured to implement part or all of the features described herein.

Further, as described herein, cellular communication circuitry <NUM> and short-range wireless communication circuitry <NUM> may each include one or more processing elements. In other words, one or more processing elements may be included in cellular communication circuitry <NUM> and also in short range wireless communication circuitry <NUM>. Thus, each of cellular communication circuitry <NUM> and short-range wireless communication circuitry <NUM> may include one or more integrated circuits (ICs) that are configured to perform the functions of cellular communication circuitry <NUM> and short-range wireless communication circuitry <NUM>, respectively. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of cellular communication circuitry <NUM> and short-range wireless communication circuitry <NUM>.

<FIG> illustrates one possible block diagram of a wireless node <NUM>, which may be one possible exemplary implementation of the device <NUM> illustrated in <FIG>. As shown, the wireless node <NUM> may include a system on chip (SOC) <NUM>, which may include portions for various purposes. For example, as shown, the SOC <NUM> may include processor(s) <NUM> which may execute program instructions for the wireless node <NUM>, and display circuitry <NUM> which may perform graphics processing and provide display signals to the display <NUM>. The SOC <NUM> may also include motion sensing circuitry <NUM> which may detect motion of the wireless node <NUM>, for example using a gyroscope, accelerometer, and/or any of various other motion sensing components. The processor(s) <NUM> may also be coupled to memory management unit (MMU) <NUM>, which may be configured to receive addresses from the processor(s) <NUM> and translate those addresses to locations in memory (e.g., memory <NUM>, read only memory (ROM) <NUM>, flash memory <NUM>). The MMU <NUM> may be configured to perform memory protection and page table translation or set up. In some embodiments, the MMU <NUM> may be included as a portion of the processor(s) <NUM>.

As shown, the SOC <NUM> may be coupled to various other circuits of the wireless node <NUM>. For example, the wireless node <NUM> may include various types of memory (e.g., including NAND flash <NUM>), a connector interface <NUM> (e.g., for coupling to a computer system, dock, charging station, etc.), the display <NUM>, and wireless communication circuitry <NUM> (e.g., for <NUM> NR, LTE, LTE-A, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.).

The wireless node <NUM> may include at least one antenna, and in some embodiments, multiple antennas <NUM> and <NUM>, for performing wireless communication with base stations and/or other devices. For example, the wireless node <NUM> may use antennas <NUM> and <NUM> to perform the wireless communication. As noted above, the wireless node <NUM> may in some embodiments be configured to communicate wirelessly using a plurality of wireless communication standards or radio access technologies (RATs).

The wireless communication circuitry <NUM> may include Wi-Fi Logic <NUM>, a Cellular Modem <NUM>, and Bluetooth Logic <NUM>. The Wi-Fi Logic <NUM> is for enabling the wireless node <NUM> to perform Wi-Fi communications, e.g., on an <NUM> network. The Bluetooth Logic <NUM> is for enabling the wireless node <NUM> to perform Bluetooth communications. The cellular modem <NUM> may be capable of performing cellular communication according to one or more cellular communication technologies. Some or all components of the wireless communication circuitry <NUM> may be used for ranging communications, e.g., using WLAN, Bluetooth, and/or cellular communications.

As described herein, wireless node <NUM> may include hardware and software components for implementing embodiments of this disclosure. For example, one or more components of the wireless communication circuitry <NUM> (e.g., Wi-Fi Logic <NUM>) of the wireless node <NUM> may be configured to implement part or all of the methods described herein, e.g., by a processor executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), a processor configured as an FPGA (Field Programmable Gate Array), and/or using dedicated hardware components, which may include an ASIC (Application Specific Integrated Circuit).

Issues have developed around privacy of access point (AP) discovery, link setup, and link maintenance. In an effort to improve privacy for scanning stations, IEEE <NUM>. 11aq introduced transmission of scanning frames from random Medium Access Control (MAC) addresses. Additionally, privacy of initial public scanning may be improved by an access point's public key. For example, a non-associated wireless station may use the public key and asymmetric cryptography to setup a shared key with the access point. The shared key may be used to encrypt unicast scanning, authentication, and association frames to ensure the privacy of the non-associated station and access point. Further, in IEEE <NUM>. 11be, there are proposals to define a Robust Multi-link Device (MLD) Query Request and MLD Query response frames as well as Robust Re-association frames. These frames can be used in an associated state to improve the privacy of the wireless station. The wireless station may perform dummy link setup and then, in associated state, private discovery and link setup with optimized parameters. In addition, IEEE <NUM>. 11md introduced Integrity check sum for the beacon frames. Thus, associated stations can verify that the associated access point transmitted the beacon frame.

In current implementations, an access point (AP) Multi Link Device (MLD) node may need to manage and/or optimize its affiliated APs. Thus, an AP MLD node should be able to add more affiliated APs to increase capacity, manage Basic Service Sets (BSSs) interference and coverage, including switching APs to operate in channels with least interference, and/or steer associated non-AP MLD nodes to operate on best performing APs and/or AP MLD nodes. Thus, an AP MLD node may need mechanisms to add affiliated APs to the AP MLD. However, in current implementations, non-AP MLD nodes create all links (e.g., associations between affiliated STAS in non-AP MLD and APs affiliated in AP MLD) upon association with the AP MLD and association request and response signaling are unprotected. This is a privacy threat for the non-AP MLD node and AP MLD as integrity, traceability, and/or privacy of the association signaling may be compromised. Additionally, association resets many parameters such as sequence number (SN), packet number (PN), Block Acknowledgment, traffic specification (TSPEC) parameters, and so forth. These parameters are reset for all frame types and traffic identifiers (IDs), e.g., priority levels. Thus, if/when a non-AP MLD node uses re-association to add an AP link to the associated AP MLD, then the parameters reset interrupts transmissions in all links.

Embodiments described herein provide systems, methods, and mechanisms for robust discovery of an access point (AP) in an AP MLD node, robust link addition to an AP MLD association, AP beaconing modes when the AP is added or deleted to/from an AP MLD, and robust BSS transition management (BTM) signaling to steer a non-AP MLD to a best AP MLD and to most suitable APs, as well as privacy improvements for associated non-AP MLD. Embodiments described herein may mitigate multi-link maintenance. Note that in embodiments described herein "robust" refers to wireless communication that is configured to withstand technical faults, signal disturbances, and security threats.

For example, a protected broadcast probe response may reduce management frames storms if and/or when an AP in AP MLD changes its parameter values. As another example, a relaxed parameter change counter may indicate that a parameter has changed, but may allow new parameters to be obtained in a link. Further, embodiments described herein may improve privacy of associated non-AP MLD. For example, frame sequence numbers may be made to run in link specific range. As another example, an associated non-AP MLD may change its MLD MAC address, link specific MAC address, sequence numbers, and so forth when it is (re-)associated. As a further example, a wireless station may control whether parameter change is immediate, delayed, or whether there is a sequence of delayed changes. Additionally, embodiments described herein may improve privacy of the AP MLD. For example, an AP MLD may select APs in which it is discoverable and serves legacy wireless stations (e.g., supporting up to IEEE <NUM>. Thus, an AP MLD may serve legacy wireless stations on non-discoverable links and a new beacon frame type may be transmitted on links in which AP is not discoverable. Further, an AP may improve privacy by changing its and associated wireless stations' parameters.

In some embodiments, a non-AP MLD, e.g., such as wireless station <NUM>, may authenticate and associate to an AP in an AP MLD using default parameters. After association, the non-AP MLD may securely discover other APs, add more links, and/or optimize its link parameters. Such a scheme may aid in protection of privacy of both the non-AP MLD and the AP MLD. For example, <FIG> and <FIG> illustrate block diagrams of examples of methods for secure multilink setup, according to some embodiments. The methods shown in <FIG> and <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. Turning to <FIG>, as shown, this method may operate as follows.

At <NUM>, a wireless station (STA), such as wireless station <NUM>, may perform initial scanning, e.g., to discover one or more APs in an AP MLD. The initial scanning may include transmitting one or more probe requests and/or receiving one or more probe responses and/or beacons.

At <NUM>, the STA may (optionally) perform additional scanning, e.g., to discover one or more additional links.

At <NUM>, the STA may authenticate with the AP. The authentication may be open, e.g., without a password, or in the authentication AP and STA may verify that they provided and/or proved possession of the password. For instance, STAs may use Simultaneous Authentication of the Equals (SAE) algorithm in authentication.

At <NUM>, the STA may perform "dummy" or placeholder MLD setup with the authenticated AP. In other words, when the discovered AP does not have a public key, the STA may need to send its association signaling/MLD Setup signaling without encryption. Thus, the STA may minimize its private information sharing during MLD setup. The STA may also minimize its information transmission in discovery. For example, the STA may use passive and/or very simple active scanning. Hence, the MLD Setup/association may be simple and the STA may use default parameter values in MLD Setup.

At <NUM>, the STA may perform a <NUM>-way handshake with the discovered AP. The <NUM>-way handshake may then authenticate the discovered AP.

At <NUM>, the STA may perform robust discovery with the associated AP. Thus, the STA may use a robust MLD discovery scheme to discover all APs in the associated AP MLD, including robust discovery MLD probe requests and responses and as well robust MLD query requests and responses. In some embodiments, such communication may be secured using a robust management frame.

At <NUM>, the STA may perform robust re-association or link add signaling within the associated AP MLD, e.g., as necessary and/or as needed. Thus, the STA may use a robust MLD re-association/link setup scheme to setup links with its capabilities and operation parameters optimized for the AP. Alternatively or additionally the STA may also change the parameter values it used in the dummy association. The robust MLD re-association/link setup scheme may include using robust re-association requests and robust re-association responses. In some embodiments, such communication may be secured using a robust management frame.

Turning to <FIG>, as shown, this method may operate as follows.

At <NUM>, the STA may (optionally) setup an encryption key to encrypt frames before the STA has associated with a discovered AP in the AP MLD. In some embodiments, the discovered AP's public key may be received out-of-band, e.g., via a local quick response (QR) code, an authentication server, and so forth. In some embodiments, the discovered AP's public key may be received over an initial wireless link established between the STA and the discovered AP. The STA uses AP's public key to encrypt a message that is used to derive symmetric key between STA and AP. The symmetric key is used to encrypt the messages before the STA has associated with the AP. If the AP's public key is available, the STA may encrypt the authentication and association signaling.

At <NUM>, the STA may perform authentication with the AP to initiate association process. For instance, the authentication may use SAE authentication protocol. The authentication messages may be protected by the symmetric key derived with the AP at <NUM>.

At <NUM>, the STA may associate with the AP. In the association, the STA may establish all links that it desires to use. The association request and response may be protected by the symmetric key derived with the AP at <NUM>.

At <NUM>, the STA may perform a <NUM>-way handshake with the AP. The <NUM>-way handshake may then authenticate the associated AP. The <NUM>-way handshake messages may be protected by the symmetric key derived with the AP at <NUM>.

At <NUM>, the STA may perform robust discovery with the associated AP. Thus, the STA may use a robust MLD discovery scheme to discover all APs in the associated AP MLD, including robust discovery MLD probe requests and responses and as well robust MLD query requests and responses. In some embodiments, such communication may be secured using a robust management frame. Note that after the STA has established keys via the <NUM>-way handshake, the STA may discontinue use of the symmetric key derived with the AP at <NUM>.

In some embodiments, e.g., as illustrated by <FIG>, when an AP MLD adds a new affiliated AP, the new AP may be included in a transmitted Reduced Neighbor Report (RNR) element and multilink element. In some embodiments, a beacon may contain a set of new AP parameters. Additionally, associated STAs may detect the new AP by receiving beacons from other APs in the AP MLD. Further, legacy STAs may find the new AP through passive and/or active scanning. In some embodiments, an AP MLD may mitigate link add storms by delaying new AP parameters transmission in beacons. Thus, as shown in <FIG>, a multilink (ML) entity <NUM> may include APs 612a and 612b. APs 612a and 612b may transmit beacons 610a and 610b, respectively. The beacons 610a and 610b may include respective RNR information and ML element information. Then, when the ML entity <NUM> adds AP 612c (e.g., a new AP), the AP 612c may also transmit a beacon 610c that may include RNR information and ML element information for AP 612c.

In some embodiments, e.g., as illustrated by <FIG>, an associated non-AP MLD (e.g., such as wireless station <NUM> and or wireless node <NUM>) may send a robust ML query request to query available APs and associated parameters in the AP MLD. In other words, the associated non-AP MLD may perform secure multilink scanning. As shown, non-AP MLD <NUM> may be associated with ML entity <NUM> and may include STAs 606a-c. STA 606a may send a robust ML query request <NUM> to AP 612a. AP 612a may respond with a response <NUM>. The response <NUM> may be a unicast ML query response to STA 606a or may be a broadcast (ML) probe response that responds to request <NUM> as well as one or more additional requests (e.g., from other STAs). Additionally, as shown, STA 606b may have an established link <NUM> with AP 612b.

In some embodiments, the response <NUM> may be considered an integrity protected broadcast probe response. The integrity protected broadcast probe response may include a medium access control (MAC) Management Encapsulation element (MME). The MME may be the last element in a frame. As illustrated by <FIG>, an integrity protected broadcast probe response may include a header, a timestamp, an interval element, and various information elements, including the MME. Additionally, as shown in <FIG>, the MME may include an element identifier (ID) field, a length field, a key ID field, a Beacon Integrity Packet Number (BIPN) field and/or a probe response integrity packet number (PRPN), and a message integrity check (MIC) field. In some embodiments, an integrity check sum may be calculated over the entire probe response and the timestamp field may be masked (e.g., set to <NUM>) prior to the integrity check sum calculation. In some embodiments, the probe response may use the same Beacon Integrity Group Temporal Key (BIGTK) as used for beacon integrity verification. Additionally, the probe response may use the same BIPN, e.g., as illustrated by <FIG>, as beacons or have a separate PRPN, e.g., as illustrated by <FIG>. Further, STAs that have BIGTK security association (BIGTKSA) may verify the integrity of the broadcast probe response.

In some embodiments, e.g., as illustrated by <FIG>, an associated non-AP MLD (e.g., such as wireless station <NUM> and or wireless node <NUM>) may add a new link (e.g., link <NUM>) without interrupting operation of other links via a robust add link request (e.g., request <NUM>) and a robust add link response (e.g., response <NUM>). In some embodiments, sequence number (SN), packet number (PN), caches, block acknowledgments, TSPECs, and so forth between non-AP MLD <NUM> and ML entity <NUM> may not be reset. In some embodiments, a Group Temporal Key (GTK) may be provided for the new link. Additionally, once the new link is added, non-AP STA and MLD parameters may be tuned to with AP MLD. Note that the robust add link request and response may be secure and private, e.g., by using an integrity protected broadcast probe response as described in reference to <FIG>.

<FIG> illustrates an example of signaling for providing a GTK for a new link, according to some embodiments. The signaling shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the signaling shown may be performed concurrently, in a different order than shown, or may be omitted. Additional signaling may also be performed as desired. As shown, this signaling may flow as follows.

Signaling <NUM> may associate STA 606a with AP 612a, e.g., as described herein. Then, STA 606a may send an add link request <NUM> to AP 612a. The add link request <NUM> may indicate that a link for STA 606b is to be added. The add link request <NUM> may be a robust add link request, e.g., as described herein. In some embodiments, for each added link, a complete set of non-AP STA parameters and AP parameters may be provided. Note that if a non-default TID-to-link mapping is used, the robust re-association may include TID-To-Link mapping, otherwise default mapping (transmission of all TIDs on all links may be used). Additionally, a power mode (PM) for the link may be provided by the non-AP STA (e.g., STA 606a) for the link. Further, the non-AP MLD (e.g., non-AP MLD <NUM>) may provide multilink attributes that may specify its non-STR/STR capability (e.g., whether the non-AP MLD is capable of simultaneous transmission/reception on multiple links for a given set of links) with the new added link and the existing links. AP 612a may respond with an add link response <NUM>. The add link response <NUM> may indicate that the link for STA 606b may be supported by AP 612b. In other words, the new link will be added between STA 606b and AP 612b. The add link response <NUM> may be a robust add link response, e.g., as described herein. After the new link is added at <NUM>, STA 606a and AP 612a may exchange EA poll messages 810a-d as part of a <NUM>-way handshake to establish BIGTK secure architecture (BIGTKSA), an integrity GTK (IGTK) secure architecture (IGTKSA) and GTK secure architecture (GTKSA) for the new link. Note that all links use the same peer wise transient key secure architecture (PTKSA) that may already be setup via initial association for the unicast frames. Upon completion of the <NUM>-way handshake at <NUM>, STA 606a may transmit data <NUM> to AP 612b. AP 612b may transmit an acknowledgment <NUM> of the data, as shown.

<FIG> illustrates another example of signaling for providing a GTK for a new link, according to some embodiments. The signaling shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the signaling shown may be performed concurrently, in a different order than shown, or may be omitted. Additional signaling may also be performed as desired. As shown, this signaling may flow as follows.

As noted, signaling <NUM> may associate STA 606a with AP 612a, e.g., as described herein. Then, STA 606a may send an add link request <NUM> to AP 612a. The add link request <NUM> may indicate that a link for STA 606b is to be added. The add link request <NUM> may be a robust add link request, e.g., as described herein. In some embodiments, for each added link, a complete set of non-AP STA parameters and AP parameters may be provided. Note that if a non-default TID-to-link mapping is used, the robust re-association may include TID-To-Link mapping, otherwise default mapping (transmission of all TIDs on all links may be used). Additionally, a power mode (PM) for the link may be provided by the non-AP STA (e.g., STA 606a) for the link. Further, the non-AP MLD (e.g., non-AP MLD <NUM>) may provide multilink attributes that may specify its non-STR/STR capability (e.g., whether the non-AP MLD is capable of simultaneous transmission/reception on multiple links for a given set of links) with the new added link and the existing links. AP 612a may respond with an add link response <NUM>. The add link response <NUM> may indicate that the link for STA 606b may be supported by AP 612b. In other words, the new link will be added between STA 606b and AP 612b. The add link response <NUM> may be a robust add link response, e.g., as described herein. In some embodiments, STA 606a may use fast MLD transition signaling to reduce a number of transmitted frames in robust re-association. Thus, as shown, after receiving the add link response <NUM>, STA 606a may transmit a robust re-association request <NUM> indicating addition of a link for STA 606b. The robust re-association request may use robust re-association frames. AP 612a may respond with a robust re-association response <NUM> indicating the addition of the link will be supported by AP 612b. The re-association response may use robust re-association frames. Note that the robust re-association (e.g., fast MLD transition signaling) may establish BIGTKSA, IGTKSA and GTKSA for the new link. Upon completion of the addition of the new link and <NUM>-way handshake (accomplished via the fast MLD transition signaling) at <NUM>, STA 606a may transmit data <NUM> to AP 612b. AP 612b may transmit an acknowledgment <NUM> of the data, as shown.

<FIG> illustrates a further example of signaling for providing a GTK for a new link, according to some embodiments. The signaling shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the signaling shown may be performed concurrently, in a different order than shown, or may be omitted. Additional signaling may also be performed as desired. As shown, this signaling may flow as follows.

As noted, signaling <NUM> may associate STA 606a with AP 612a, e.g., as described herein. Then, STA 606a may send an add link request <NUM> to AP 612a. The add link request <NUM> may indicate that a link for STA 606b is to be added. The add link request <NUM> may be a robust add link request, e.g., as described herein. In some embodiments, for each added link, a complete set of non-AP STA parameters and AP parameters may be provided. Note that if a non-default TID-to-link mapping is used, the robust re-association may include TID-To-Link mapping, otherwise default mapping (transmission of all TIDs on all links may be used). Additionally, a power mode (PM) for the link may be provided by the non-AP STA (e.g., STA 606a) for the link. Further, the non-AP MLD (e.g., non-AP MLD <NUM>) may provide multilink attributes that may specify its non-STR/STR capability (e.g., whether the non-AP MLD is capable of simultaneous transmission/reception on multiple links for a given set of links) with the new added link and the existing links. AP 612a may respond with an add link response <NUM>. The add link response <NUM> may indicate that the link for STA 606b may be supported by AP 612b. In other words, the new link will be added between STA 606b and AP 612b. The add link response <NUM> may be a robust add link response, e.g., as described herein. In some embodiments, STA 606a may use modified fast MLD transition signaling to reduce a number of transmitted frames in robust re-association. Thus, as shown, after receiving the add link response <NUM>, STA 606a may transmit an authentication request <NUM> to AP 612A. AP 612a may respond with an authentication response <NUM>. Note that the authentication (e.g., modified fast MLD transition signaling) may establish BIGTKSA, IGTKSA, and GTKSA for the new link. Upon completion of the addition of the new link and <NUM>-way handshake (accomplished via the modified fast MLD transition signaling) at <NUM>, STA 606a may transmit data <NUM> to AP 612b. AP 612b may transmit an acknowledgment <NUM> of the data, as shown.

In some embodiments, a STA, such as STA <NUM> and/or STAs 606a-c, may hide its MLD MAC address and use link specific addresses. The non-AP MLD may define, during association, link specific MAC addresses and/or a temporary non-AP MLD address. The temporary non-AP MLD address may be used for group addressed frames and A-MSDU transmission. Actual (e.g., real) non-AP MLD address may only be used for authentication. In some embodiments, e.g., as illustrated by <FIG>, an add link request may be used to randomize STA MAC addresses.

<FIG> illustrates an example of signaling for randomizing a wireless station's MAC address, according to some embodiments. The signaling shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the signaling shown may be performed concurrently, in a different order than shown, or may be omitted. Additional signaling may also be performed as desired. As shown, this signaling may flow as follows.

Signaling <NUM> may associate STA 606a with AP 612a, e.g., as described herein. Then, STA 606a may send an add link request <NUM> to AP 612a. The add link request <NUM> may indicate a MAC address associated with a link, a new MLD MAC address sequence number (SN) offset, including TID, UL, DL, and a TSF of the update to the MAC address. The add link request <NUM> may be a robust add link request, e.g., as described herein. AP 612a may send an add link response <NUM> to STA 606a. The add link response <NUM> may indicate the MAC address associated with the link, the new MLD MAC address sequence number (SN) offset, including TID, UL, DL, and the TSF of the update to the MAC address. Upon reception of the add link response <NUM>, the new MAC address may be implemented (e.g., an immediate parameter change) or a delay may occur prior to the new MAC address being implemented (e.g., a delayed parameter change). Note that multiple future changes to the MAC address may also be scheduled. For example, each STA in a non-AP MLD and AP in an AP MLD may change its parameters at a different schedule and/or on the same schedule. Note that there may be multiple sequence number spaces used (e.g., for unicast management frames, there may be Traffic ID (TID)/priority level specific unicast data sequence number offsets). For each of the sequence number spaces, a sequence number offset may be defined separately. In some embodiments, it may be recommended to change sequence number offsets for all TIDs and frame types when a STA and/or AP specific address changes.

In some embodiments, the SN offset (e.g., included in the add link request <NUM>/add link response <NUM>) may be randomized, e.g., to make it more difficult for third parties to detect wireless stations that belong to a non-AP MLD. In some embodiments, SN offsets may be link specific. <FIG> illustrates a block diagram of an example of a method for randomizing SN offsets, according to some embodiments. The method shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, this method may operate as follows.

At <NUM>, an application and/or website (e.g., Internet) may generate data (e.g., one or more MAC PDUs) that may be received into a transmission buffer at <NUM>. The transmission buffer may map the MAC PDUs (MPDUs) to sequence numbers (SNs). The transmission buffer may forward the MAC PDUs, e.g., based on sequence number, to one or more transmit queues, each transmit queue associated with a link between a non-AP MLD and an ML entity. At <NUM>, a first transmit queue associated with a first link may receive an MPDU with an associated SN. The first transmit queue may add a link offset (e.g., Offset_link <NUM>) to the SN to generate a link specific SN, e.g., SN_link1. Similarly, at <NUM>, a second transmit queue associated with a second link may receive an MPDU with an associated SN. The second transmit queue may add a link offset (e.g., Offset_link <NUM>) to the SN to generate a link specific SN, e.g., SN_link2. Further, at <NUM>, a third transmit queue associated with a third link may receive an MPDU with an associated SN. The third transmit queue may add a link offset (e.g., Offset_link <NUM>) to the SN to generate a link specific SN, e.g., SN_link3. At <NUM>, a first receive buffer may receive an MPDU with a sequence number of SN_link1 from the first transmit queue via the first link. The first receive buffer may determine the sequence number associated with MPDU by removing the SN offset associated with the first link, e.g., Offset_link1. Similarly, at <NUM>, a second receive buffer may receive an MPDU with a sequence number of SN_link2 from the second transmit queue via the second link. The second receive buffer may determine the sequence number associated with MPDU by removing the SN offset associated with the second link, e.g., Offset_link2. Further, at <NUM>, a third receive buffer may receive an MPDU with a sequence number of SN_link3 from the third transmit queue via the third link. The third receive buffer may determine the sequence number associated with MPDU by removing the SN offset associated with the third link, e.g., Offset_link3. At <NUM>, a reorder buffer may reorder the MPDUs received via the first, second, and third receive buffers based on the determine sequence numbers of each MPDU. At <NUM>, a server of the website and/or application may receive the data.

In some embodiments, MPDUs transmitted after a scheduled MAC address and/or sequence number change time may use new parameters (e.g., associated with updated MAC address and/or sequence number). In some embodiments, MPDUs transmitted after TSF time, e.g., as illustrated by <FIG>, may use the new parameters. Note that MPDUs transmitted prior to the TSF time may use current (e.g., old) parameters. In some embodiments, retransmissions and MPDUs that are buffered in a link specific transmission queue (e.g., as of the TSF time) may use current (e.g., old) values. Note that MPDUs transmitted in a physical PDU (PPDU) may use only new or old parameter values. As further illustrated by <FIG>, in some embodiments, a scheduled MAC address and/or sequence number (e.g., parameters) change time may include a tolerance time. As shown, when a transmission opportunity, such as TXOP <NUM>, is initiated during the tolerance time, a receiver may detect from an AID and MAC Addresses whether the transmitted PPDU has the new or current parameter values, e.g., as further described with reference to <FIG>. Thus, PPDUs/MPDUs transmitted during the tolerance time may use either current or new parameter values. However, TXOPs initiated after the tolerance time will be received only if PPDUs/MPDUs are transmitted with the new parameter values.

<FIG> illustrates a block diagram of an example of a method for selecting an SN offset during a parameters change, according to some embodiments. The method shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, this method may operate as follows.

At <NUM>, a receiver, e.g., such as an AP of a ML entity, may receive a MAC PDU (MPDU) over a link with a non-AP MLD, e.g., from a wireless station of a non-AP MLD. At <NUM>, the receiver may determine whether parameters associated with the MPDU are parameters used prior to a parameters change time (e.g., old parameters) or parameters used after the parameters change time (e.g., new parameters). At <NUM>, in response to determining that the parameters associated with the MPDU are old parameters, the receiver may determine whether the MPDU was transmitted during a tolerance time. At <NUM>, in response to determining that the MPDU was transmitted after the tolerance time, the receiver may discard the MPDU. Alternatively, at <NUM>, in response to determining that the MPDU was transmitted before and/or during the tolerance time, the receiver may acknowledge the MPDU and determined a sequence number of the MPDU using an SN offset used prior to the parameters change time (e.g., an old SN offset). The receiver may then add the MPDU to a reorder buffer using the determine sequence number. Further, at <NUM>, in response to determining that the parameters associated with the MPDU are new parameters, the receiver may acknowledge the MPDU and determine a sequence number of the MPDU using an SN offset used after the parameters change time (e.g., a new SN offset). The receiver may then add the MPDU to a reorder buffer using the determined sequence number.

In some embodiments, APs of an ML entity may operate in various phases during an AP addition to the ML entity. For example, <FIG> illustrates examples of various operational phases of APs of an ML entity during an AP addition, according to some embodiments. As shown, an AP may be in any of six operational phases during an AP addition. In an open phase (e.g., a default operational mode), an AP may remain in an active mode and may be visible to all wireless stations within range. In a hidden phase, an AP may not be included to a reduced neighbor report (RNR) and ML element of other APs in an AP MLD. Note that while in the hidden phase, the AP may only be discoverable on its primary channel. In an encrypted phase, an AP may transmit encrypted beacons and may be visible only to selected wireless stations that know the AP beacon encryption key. In an off phase, the AP may be non-operational. In a closing and/or closing encrypted phase, an AP may be closing (e.g., transitioning to the off phase) and may be in the process of safely terminating links to all wireless stations. As shown in <FIG>, a primary AP 1312a may remain in an open phase of operation during addition of one or more APs (e.g., secondary APs 1312b and 1312c). Secondary AP 1312b, upon addition, may transition from an off phase to an encrypted phase and may only be discoverable to selected wireless stations (e.g., as selected by primary AP 1312a). After a time period, the secondary AP 1312b may decide to transition to an off phase and may include a closing encrypted phase prior to the off phase, e.g., to safely terminate links to wireless stations associated with AP 1312b. Secondary AP 1312c, upon addition, may transition from an off phase to a hidden phase prior to transitioning to an open phase. The hidden phase may aid in the AP 1312c avoiding link signaling storms upon entering the open phase. After a time period in the open phase, the AP 1312c may decide to transition to an off phase and may include a closing phase prior to the off phase, e.g., to safely terminate links to wireless stations associated with AP 1312c.

In some embodiments, APs of an ML entity (e.g., APs of an AP MLD) may operate in various beaconing modes. In such embodiments, an AP broadcasting in a hidden beaconing mode, private beaconing mode, encrypted beaconing mode, and/or not transmitting beacons may not be included to RNR and ML elements in beacons, probe responses, and/or multi-link probe response of other APs in the AP MLD. Thus, such an AP cannot be discovered by beacons received from another AP in the AP MLD. Note that an AP transmitting in a hidden beaconing mode may transmit normal beacon frames that may include other APs in the AP MLD to its RNR and ML element. Note further that an AP transmitting in a private beaconing mode may transmit normal beacon frames that do not include other APs in the AP MLD to its RNR and ML element. Additionally, an AP transmitting in an encrypted beacon mode may not use a normal beacon frame. Instead, receivers may be required to detect content of the beacon frame. e.g., the beacon frame may be encrypted by a GTK used for management frames. Such a beacon frame may shorter than a normal beacon frame. Additionally, such a beacon frame may not include SSID, security parameters, and/or BSS performance parameters. Such a beacon frame may include other APs in the AP MLD to its RNR and ML element.

For example, <FIG> illustrate examples of various beaconing modes for APs affiliated in AP MLD, according to some embodiments. As shown in <FIG>, when all APs are in a default beaconing mode, beacons from AP1 1412a may include a ML indicator with values for AP1 1412a, AP2 1412b, and AP3 1412c and an RNR indicator with values for AP2 1412b and AP3 1412c. Similarly, beacons from AP2 1412b may include a ML indicator with values for AP1 1412a, AP2 1412b, and AP3 1412c and an RNR indicator with values for AP1 1412a and AP3 1412c. Further, beacons from AP3 1412c may include a ML indicator with values for AP1 1412a, AP2 1412b, and AP3 1412c and an RNR indicator with values for AP1 1412a and AP2 1412b. As shown in <FIG>, AP3 1412c may be in a hidden/encrypted beaconing mode. Thus, beacons from AP1 1412a may include a ML indicator with values for AP1 1412a and AP2 1412b but not AP3 1412c and an RNR indicator with a value for AP2 1412b. Similarly, beacons from AP2 1412b may include a ML indicator with values for AP1 1412a and AP2 1412b but not AP3 1412c and an RNR indicator with a value for AP1 1412a. Further, beacons from AP3 1412c may include a ML indicator with values for AP1 1412a, AP2 1412b, and AP3 1412c and an RNR indicator with values for AP1 1412a and AP2 1412b. As shown in <FIG>, AP3 1412c may be in a private beaconing mode. Thus, beacons from AP1 1412a may include a ML indicator with values for AP1 1412a and AP2 1412b but not AP3 1412c and an RNR indicator with a value for AP2 1412b. Similarly, beacons from AP2 1412b may include a ML indicator with values for AP1 1412a and AP2 1412b but not AP3 1412c and an RNR indicator with a value for AP1 1412a. Further, beacons from AP3 1412c may not include an ML indicator or an RNR indicator. As shown in <FIG>, AP3 may not be transmitting a beacon. Thus, beacons from AP1 1412a may include a ML indicator with values for AP1 1412a and AP2 1412b but not AP3 1412c and an RNR indicator with a value for AP2 1412b. Similarly, beacons from AP2 1412b may include a ML indicator with values for AP1 1412a and AP2 1412b but not AP3 1412c and an RNR indicator with a value for AP1 1412a.

<FIG> illustrates an example of AP beaconing, according to some embodiments. As shown, at <NUM>, a primary AP 1512a may remain in an open phase of operation during addition of one or more APs (e.g., secondary APs 1512b and 1512c). During <NUM>, APs 1512b and 1512c may be off and AP 1512a may transmit beacons with only information associated with AP 1512a.

At <NUM>, AP 1512c may transition to a hidden mode of operation while AP 1512b remains off. During <NUM>, AP 1512a may transmit beacons with only information associated with AP 1512a (e.g., AP 1512a does not include information such as RNR and ML elements associated with AP 1512c). However, AP 1512c may transmit beacons with information associated with AP 1512c as well as AP 1512a (e.g., RNR and ML elements associated with AP 1512a).

At <NUM>, AP 1512c may transition to an open mode of operation while AP 1512b remains off. During <NUM>, AP 1512a may transmit beacons with information associated with AP 1512a as well as AP 1512c (e.g., RNR and ML elements associated with AP 1512c). Similarly, AP 1512c may transmit beacons with information associated with AP 1512c as well as AP 1512a (e.g., RNR and ML elements associated with AP 1512a).

At <NUM>, AP 1512b may transition to an encrypted mode of operation. During <NUM>, AP 1512a may transmit beacons with information associated with AP 1512a as well as AP 1512c (e.g., RNR and ML elements associated with AP 1512c). Similarly, AP 1512c may transmit beacons with information associated with AP 1512c as well as AP 1512a (e.g., RNR and ML elements associated with AP 1512a). AP 1512b, however, may transmit beacons with information associated with AP 1512a (e.g., RNR and ML elements associated with AP 1512a). and AP 1512c (e.g., RNR and ML elements associated with AP 1512c). Note that AP 1512b may not include such information in probe responses.

At <NUM>, AP 1512b may transition to an encrypted closing mode of operation. During <NUM>, AP 1512a may transmit beacons with information associated with AP 1512a as well as AP 1512c (e.g., RNR and ML elements associated with AP 1512c). Similarly, AP 1512c may transmit beacons with information associated with AP 1512c as well as AP 1512a (e.g., RNR and ML elements associated with AP 1512a). AP 1512b, however, may transmit beacons with information associated with AP 1512a (e.g., RNR and ML elements associated with AP 1512a). and AP 1512c (e.g., RNR and ML elements associated with AP 1512c). Note that AP 1512b may not include such information in probe responses. Additionally, during <NUM>, AP 1512b may signal that it will close down.

At <NUM>, AP 1512b may transition to off. During <NUM>, AP 1512a may transmit beacons with information associated with AP 1512a as well as AP 1512c (e.g., RNR and ML elements associated with AP 1512c). Similarly, AP 1512c may transmit beacons with information associated with AP 1512c as well as AP 1512a (e.g., RNR and ML elements associated with AP 1512a).

At <NUM>, AP 1512c may transition to a closing mode of operation. During <NUM>, AP 1512a may transmit beacons with information associated with AP 1512a as well as an indication that AP 1512c will close down. Similarly, AP 1512c may transmit beacons with information associated with AP 1512c as well as AP 1512a (e.g., RNR and ML elements associated with AP 1512a). Additionally, during <NUM>, AP 1512c may signal that it will close down.

At <NUM>, AP 1512c may transition to off. During <NUM>, AP 1512a may transmit beacons with only information associated with AP 1512a.

<FIG> further illustrates distinctions for various AP operational modes, according to some embodiments. As shown, and as described herein, an AP of an AP MLD operating in a default (and/or legacy) mode of operation may be discoverable via any of the APs in the AP MLD. Additionally, AP and link quality assessment may occur across all links or via an ML probe request. Additionally, when operating in a default mode, all links may be setup in a <NUM>-phase setup. Further, as described herein, an AP of an AP MLD operating in a hidden mode of operation may only be discoverable on its link (e.g., a hidden AP is not discoverable via a link to another AP in the AP MLD). Additionally, AP and link quality assessment may be slow as compared to default operation and only a link to primary AP may be assessed with secondary APs likely being setup in a post association state. Further, an AP of an AP MLD operating in an encrypted mode and/or not transmitting beacons may not be discoverable, e.g., only a primary AP may be discoverable. AP and link quality assessment may only be performed with the primary AP with secondary APs being assess in a post-associated state. Further secondary APs may be setup only in a post association state.

In some embodiments, a wireless station in non-AP MLD may query available APs in an AP MLD via a robust multilink (ML) Query procedure. The ML Query may identify a requested AP and/or the ML Query may request information of all APs in the AP MLD. The requested AP may be transmitting hidden, encrypted and/or private beacons. In such cases, an AP in the AP MLD may transmit a unicast robust ML Query response to the wireless station and provide AP parameters for the requested AP. Alternatively, if and/or when the AP does not want the wireless station to find the requested AP and add a link to the requested AP, the AP may not respond with unicast robust ML Query response. Additionally, the AP may not provide any information of the requested AP.

In some embodiments, a soft AP of an AP MLD may have secondary AP(s) that operate in the <NUM> and/or <NUM> bands, where a soft AP may be a mobile phone/tablet/laptop that may switch to operate as an AP. Typically, a soft AP does not operate secondary AP(s), unless traffic load requires more capacity. However, a soft AP may dynamically add or delete secondary APs. Note that a discoverable secondary AP may operate in active mode and may be included to beacons transmitted by other APs whereas a hidden secondary AP may operate in a power save mode and/or have other limitations (e.g., as further described herein). In some embodiments, although all APs of an infrastructure AP MLD may be typically available all the time, an AP MLD may temporarily disable AP, e.g., if traffic load is high and/or if the AP needs to do measurements and/or other operations. Infrastructure APs may be independent and there may be no primary AP. Further, infrastructure APs may be simultaneous TX and RX capable, e.g., they may transmit and receive independently.

In some embodiments, APs that serve legacy wireless stations may be required to select a default mode of operation in which beacons are transmitted on all links, the AP is always available, and the AP is capable of simultaneous TX and RX. In some embodiments, a hidden AP may transmit selected group frames, may be available based on TWT schedule, and may be not be capable of simultaneous TX and RX. Note that an AP operating as a hidden AP may operate with any of the above features (e.g., may operate as a default AP) if the hidden AP has only associated with non-AP MLDs that support the operation.

BSS transition management (BTM) signaling may allow an AP to propose BSS transition to an associated wireless station (STA). A non-AP STA may send a BTM query to an AP to query candidate APs from its associated APs. An associated AP may send a BTM request to propose transition to an AP for the STA. the STA may respond with a BTM response to accept and/or reject the proposed transition. In some embodiments, the BTM request may be sent to a non-AP MLD. For example, an AP MLD may send a BTM request to an associated non-AP MLD to request MLD/BSS transition to another AP/AP MLD, a new link addition to the associated AP MLD, and/or to disassociate a link/AP from the associated AP MLD. For a request for MLD/BSS transition to another AP/AP MLD, the non-AP MLD may perform a <NUM>-way handshake and current links may be deleted and new links to the new AP MLD may be created. For a new link addition to the associated AP MLD, the AP MLD may signal to the STA that it has a new AP and the new AP may not be not discoverable for all STAs. Additionally, the BTM request may be the only mechanism to discover the new AP, at least in some embodiments. For a request to disassociate a link/AP from the associated AP MLD, the AP may shut down and the AP MLD may request that the STA stop using the AP.

<FIG> illustrates an example of BSS transition management usage, according to some embodiments. As shown, at <NUM>, a primary AP 1712a may remain in an open phase of operation during addition of one or more APs (e.g., secondary APs 1712b and 1712c). During <NUM>, APs 1712b and 1712c may be off and AP 1712a may transmit beacons with only information associated with AP 1712a. AP 1712a may not transmit BTM frames.

At <NUM>, AP 1712c may transition to a hidden mode of operation while AP 1712b remains off. During <NUM>, AP 1712a may transmit BTM requests to selected STAs. The BTM request frames may include an indication of a request for legacy STAs to transition to AP 1712c. Additionally, the BTM frames may include an indication of a request to non-AP MLDs to add a link to AP 1712c. Further, AP 1712a may transmit beacons with only information associated with AP 1712a (e.g., AP 1712a does not include information such as RNR and ML elements associated with AP 1712c). However, AP 1712c may transmit beacons with information associated with AP 1712c as well as AP 1712a (e.g., RNR and ML elements associated with AP 1712a).

At <NUM>, AP 1712c may transition to an open mode of operation while AP 1712b remains off. During <NUM>, AP 1712a may transmit beacons with information associated with AP 1712a as well as AP 1712c (e.g., RNR and ML elements associated with AP 1712c). Similarly, AP 1712c may transmit beacons with information associated with AP 1712c as well as AP 1712a (e.g., RNR and ML elements associated with AP 1712a).

At <NUM>, AP 1712b may transition to an encrypted mode of operation. During <NUM>, APs 1712a and 1712c may transmit BTM request to selected stations. The BTM frames may be transmitted to selected non-AP MLDs and may include an indication of a request to add a link to AP 1712b. Further, AP 1712a may transmit beacons with information associated with AP 1712a as well as AP 1712c (e.g., RNR and ML elements associated with AP 1712c). Similarly, AP 1712c may transmit beacons with information associated with AP 1712c as well as AP 1712a (e.g., RNR and ML elements associated with AP 1712a). AP 1712b, however, may transmit beacons with information associated with AP 1712a (e.g., RNR and ML elements associated with AP 1712a). and AP 1712c (e.g., RNR and ML elements associated with AP 1712c). Note that AP 1712b may not include such information in probe responses.

At <NUM>, AP 1712b may transition to an encrypted closing mode of operation. During <NUM>, APs 1712a, 1712b, and 1712c may transmit BTM requests. The BTM frames may be transmitted to non-AP MLDs that have a link with AP 1712b and may include an indication that AP 1712b will close. Further, AP 1712a may transmit beacons with information associated with AP 1712a as well as AP 1712c (e.g., RNR and ML elements associated with AP 1712c). Similarly, AP 1712c may transmit beacons with information associated with AP 1712c as well as AP 1712a (e.g., RNR and ML elements associated with AP 1712a). AP 1712b, however, may transmit beacons with information associated with AP 1712a (e.g., RNR and ML elements associated with AP 1712a). and AP 1712c (e.g., RNR and ML elements associated with AP 1712c). Note that AP 1712b may not include such information in probe responses.

At <NUM>, AP 1712b may transition to off. During <NUM>, AP 1712a may transmit beacons with information associated with AP 1712a as well as AP 1712c (e.g., RNR and ML elements associated with AP 1712c). Similarly, AP 1712c may transmit beacons with information associated with AP 1712c as well as AP 1712a (e.g., RNR and ML elements associated with AP 1712a).

At <NUM>, AP 1712c may transition to a closing mode of operation. During <NUM>, APs 1712a and 1712c may transmit BTM requests. BTM frames transmitted to legacy non-AP STAs associated with AP 1712c may include an indication to move to AP 1712a. BTM frames transmitted to non-AP MLDs that have a link with AP 1712c may include an indication that AP 1712c will close. Further, AP 1712a may transmit beacons with information associated with AP 1712a as well as an indication that AP 1712c will close down. Similarly, AP 1712c may transmit beacons with information associated with AP 1712c as well as AP 1712a (e.g., RNR and ML elements associated with AP 1712a).

At <NUM>, AP 1712c may transition to off. During <NUM>, AP 1712a may transmit beacons with only information associated with AP 1712a. Note that in each of the above phases <NUM>-<NUM>, available APs may respond to BTM queries of associated STAs.

<FIG> illustrates a request mode field of a BTM request, according to some embodiments. As shown the request mode field may include a preferred candidate list included field (e.g., to indicate that a preferred candidate list is included in the BTM request), an abridged field, a disassociation imminent field, a BSS termination included field, and ESS dissociation imminent field, an AP MLD termination included field, a New AP to be added field, and a reserved field. In some embodiments, each field may be <NUM> bit. In some embodiments, when an AP MLD makes a new AP discoverable to all STAs at the same time, then all associated non-AP MLDs may add a link to the new AP at the same time, which may cause a management frame storm. In some embodiments, to mitigate management frame storms, an AP MLD may signal the new AP availability only to selected STAs by using a BTM request frame, e.g., as described herein. In some embodiments, the BTM request may propose STAs to create a link to the new AP, e.g., via the request mode New AP to be added field. For example, the BTM request may set a New AP To Be Added field of the request mode field to a value of <NUM>, e.g., to request that the STA creates a link to the AP listed in the candidate list. The AP in the candidate list may not be included in an RNR and ML element to avoid link add storms. The new AP may send a beacon and respond to probe requests. Additionally, a Validity Interval field of the BTM request may signal a number of TBTTs until the new AP is added to all beacons.

In some embodiments, a BTM request may indicate AP MLD/BSS termination. In some embodiments, the BTM request can signal BSS Termination Included signals that the transmitting AP is shutting down. Thus, when an AP MLD transmits the BTM request with this field set to <NUM>, the AP in AP MLD may shut down. Additionally, an AP MLD Termination Included field set to a value of <NUM> may signal that the AP MLD with all its APs will shut down.

In some embodiments, a non-AP MLD may send a response to the BTM request via a BTM response. In the BTM response, the non-AP MLD may indicate acceptance or rejection of the BTM request. In some embodiments, the BTM response does not terminate and/or perform AP MLD transition. In other words, link add/fast MLD transition/link delete signaling may be required to be separately signaled.

In some embodiments, the AP MLD may send a BTM request that indicates AP termination to all non-AP MLDs that have a link with the AP/BSS that is terminating and to all non-AP STAs that may be associated with the AP/BSS that is terminating. The AP MLD may receive a response from all associated non-AP STAs and from all non-AP MLDs that have a link with the AP/BSS before it terminates the AP/BSS.

In some embodiments, the AP MLD may signal, e.g., in beacon frames, that an AP in AP MLD will be closing. The AP MLD may signal long duration, multiple DTIM beacon intervals, or beacon intervals, after which the AP/BSS will be terminated. The AP may signal AP termination at least for the longest Listening Interval of all associated STAs and non-AP MLDs. A STA and/or non-AP MLD may receive at least one beacon within its Listening Interval. The Listening Interval value may typically be signaled in association. The broadcasted termination indication may be useful, e.g., if the AP has a link with many STAs affiliated with non-AP MLDs and unicast BTM request/response signaling would cause high signaling overhead.

In some embodiments, different bands may have different minimum durations for the AP/BSS. For example, UNII-<NUM> bands in <NUM> may signal BSS termination for a shorter time. This time may be similar to durations of the channel switch announcements when radar is detected in the band.

In some embodiments, a beacon transmission mode may define a minimum time an AP is required to signal a BSS termination duration. For instance, if the BSS transmits in hidden or encrypted mode, the minimum duration to signal AP termination may be shorter than in default/legacy beaconing mode.

In some embodiments, an AP may transmit broadcast BTM request frames to signal that AP/BSS in AP MLD will be terminated. This signaling may be understood by legacy STAs. Note that if a STA receives such broadcast BTM request, but desires to continue operating in the AP, e.g., opposes AP termination, the STA may send a unicast BTM response with status code reject for the AP termination. Further, if the AP termination is acceptable for the non-AP MLD, it may send a link delete message to terminate the link and/or send a unicast BTM response with status code accept or do nothing.

In some embodiments, an AP may be terminated earlier, e.g., if it does not have any associated STAs or links to AP MLD. This may happen if all non-AP MLDs delete their links to the AP and legacy STAs disassociate from the AP.

In some embodiments, the AP MLD may send in beacon frames and send unicast and/or broadcast BTM request messages to signal that it is terminating AP/BSS. In some embodiments, an AP may perform both signaling in parallel to ensure that STAs do not miss AP termination indication.

In some embodiments, a non-AP MLD may transmit a BTM query frame, e.g., if the non-AP MLD does not know the available APs in AP MLD and/or if the non-AP MLD wants to query for APs and/or AP MLDs that network recommends for the STA. The non-AP MLD may also send an ML Query Request, e.g., if the non-AP MLD is interested to operate with the responding AP MLD. In other words, the non-AP MLD may also send an ML Query Request if the non-AP MLD does not want to change association to other AP or AP-MLD. The AP MLD may respond with ML Query response that contains similar information as the BTM Request as describe above. The AP may not provide all information to all requesting STAs, e.g., if the AP MLD does not desire the non-AP MLD to be aware of some of its APs, it may not provide information associated with those APs. The content of the AP ML Query responses may change over time, as well.

In some embodiments, AP MLD may send BTM request to specific non-AP MLD and request a link termination. The AP may use a disassociation imminent field to signal that the whole non-AP MLD is disassociated, unless the non-AP MLD terminates the link to the AP.

In some embodiments, the AP may send unicast link termination signaling to STA to indicate that it has terminated a link of the non-AP MLD. After this indication, the STA may need to add a link or associate with the link in order to use the link for transmission or reception of data.

In some embodiments, an AP may transmit a BTM request to a STA to request the STA to operate in another link and/or the AP may terminate a specific link, e.g., if the STA's link performance is very poor on the link (e.g., transmission rates are poor, AP may not get acknowledgements to DL frames it transmits, STA needs to retransmit multiple times its frames, etc.). Alternatively, the AP may terminate a link from the STA that uses a lot (e.g., a large portion) of transmission time. For example, a non-AP MLD transmits all its traffic in <NUM> and does not use <NUM> link that would have much higher transmission capacity.

In some embodiments, a BTM query may be used to add a new AP and/or request a new AP. For example, <FIG> illustrates an example of signaling for using a BTM query to add a new AP and/or request a new AP, according to some embodiments. The signaling shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the signaling shown may be performed concurrently, in a different order than shown, or may be omitted. Additional signaling may also be performed as desired. As shown, this signaling may flow as follows.

As shown, STA 606a may associated with AP 612a via signaling <NUM>, e.g., as described herein. Note that STA 606b may not be associated and AP 612b may not be operating. STA 606a (e.g., an associated non-AP STA/MLD) may send a BTM query frame <NUM> to AP 612a to propose that AP MLD <NUM> adds a new AP (e.g., AP 612b) on a specific channel. The BTM query frame <NUM> may include an indication to add the new AP and a candidate BSS. In some embodiments, the BTM query frame <NUM> may include a request mode field with a new AP to be added field set to a value of <NUM> to indicate the request for the new AP creation. In some embodiments, STA 606a (e.g., the non-AP MLD) may create an AP and provide its parameters to the STA/non-AP MLD (e.g., AP 612a). AP 612a may send a start new AP in AP MLD request <NUM> to AP 612b and include AP MLD parameters. AP 612b may send a new AP created response <NUM> to AP 612a and include AP MLD parameters. AP 612a may then send a BTM request <NUM> to STA 606a. The BTM request <NUM> may include a candidate BSS list that includes AP 612b. STA 606a may send a BTM response <NUM> indicating successful receipt of the BTM request. STA 606a may then send an add link request <NUM> requesting addition of a link between STA 606b and AP 612b. AP 612a may send a add link response <NUM> indicating the addition of the link between STA 606b and AP 612b. At <NUM> the link may be added. STA 602b may then send data (e.g., MPDUs) <NUM> to AP 612b and AP 612b may send acknowledgment <NUM> to STA 606b.

In some embodiments, a non-AP MLD may delete a link between a STA and an AP. For example, a non-AP MLD may delete a link by sending a robust delete link frame to an AP. Note that when a link is deleted, the link cannot be used to send data and the non-AP MLD does not maintain link specific keys and/or parameters.

<FIG> illustrates a block diagram of an example of a method for performing secure multilink scanning, according to the claimed invention. The method shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, this method may operate as follows.

At <NUM>, a wireless station or wireless device, such as wireless station <NUM>, associates an access point, such as access point <NUM>. The access point is included in a multi-link device (MLD).

At <NUM>, the wireless station transmits, to the access point, a robust query request. Note that as used herein, the adjective "robust" refers to a type of wireless communication that is configured to withstand technical faults, signal disturbances, and security threats. Thus, a robust query request is a query request that is configured to withstand technical faults, signal disturbances, and security threats. The robust query request queries for available access points within the MLD and for parameters associated with the MLD.

At <NUM>, the wireless station receives, from the access point a robust query response. Note that a robust query response is a query response configured to withstand technical faults, signal disturbances, and security threats. In some instances, the robust query response may include an integrity protected broadcast probe response. The integrity protected broadcast probe response may include a medium access control (MAC) Management Encapsulation element (MME). The MME may include at least one of (e.g., any combination of, including one or more of and/or all of) an element identifier (ID), a length field, a key ID field, a Beacon Integrity Packet Number (BIPN) field, a probe response integrity packet number (PRPN) field, and/or a message integrity check (MIC) field. In some instances, the robust query response may use a temporal key and/or packet number for verification. For example, the robust query response may use a Beacon Integrity Group Temporal Key (BIGTK) for verification. In such instances, the BIGTK may additionally be used for beacon integrity verification. As another example, the robust query response may use a Beacon Integrity Packet Number (BIPN). In such instances, the BIPN may be additionally used for beacons. As a further example, the robust query response may use a probe response integrity packet number (PRPN). In such instances, the PRPN may be from a PRPN used for beacons.

In some instances, the wireless station may calculate an integrity check sum over the entire robust query response. In such instances, a timestamp field included in the robust query response may be masked prior to calculating the integrity check sum, e.g., may not be included in the integrity check sum.

<FIG> illustrates a block diagram of an example of a method for providing a Group Temporal Key (GTK) for a new link, according to some embodiments. The method shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, this method may operate as follows.

At <NUM>, a wireless station or wireless device, such as wireless station <NUM>, may associate with an access point, such as access point <NUM>. The access point may be included in and/or associated with a multi-link device (MLD).

At <NUM>, the wireless station may transmit, to the access point, an add link request. The add link request may request an addition of a new link between the wireless station and the access point. The add link request may be and/or may include a robust add link request. Note that as used herein, the adjective "robust" refers to and/or describes a type of wireless communication that is configured to withstand technical faults, signal disturbances, and security threats. Thus, a robust add link request is an add link request that is configured to withstand technical faults, signal disturbances, and security threats. In some instances, the add link request may include a set of non-access point station (e.g., a set of wireless station) parameters and a set of access point parameters. In some instances, the add link request may include a power mode (PM) for the new link. In some instances, the add link request may include multilink attributes. The multilink attributes may specify whether the wireless station is capable of simultaneous transmission/reception on multiple links.

At <NUM>, the wireless station may establish, with the access point, security for the new link, including one or more of (e.g., any combination of, including at least one of and/or all of) of a Beacon Integrity GTK (BIGTK) secure architecture (BIGTKSA), an Integrity GTK secure architecture (IGTKSA), a GTK secure architecture (GTKSA), or a peer wise transient key (PTK) secure architecture (PTKSA) for the added new link. The add link response may be and/or may include a robust add link response. Note that as used herein, the adjective "robust" refers to and/or describes a type of wireless communication that is configured to withstand technical faults, signal disturbances, and security threats. Thus, a robust add link response is an add link response that is configured to withstand technical faults, signal disturbances, and security threats. In some instances, the add link response may indicate that the new link between the wireless station and the access point will be added.

In some instances, to establish security for the new link with the access point, the wireless station may perform a <NUM>-way handshake procedure with the access point. In some instances, to establish security for the new link with the access point, the wireless station may transmit, to the access point, a robust re-association request and may receive, from the access point, a robust re-association response. In some instances, to establish security for the new link with the access point, the wireless station may transmit, to the access point, an authentication request and may receive, from the access point, an authentication response.

<FIG> illustrates a block diagram of an example of a method for randomizing a medium access control (MAC) address of a wireless station, according to the claimed invention. The method shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, this method may operate as follows.

At <NUM>, a wireless station or wireless device, such as wireless station <NUM>, associates with an access point, such as access point <NUM>. The access point is included in a multi-link device (MLD).

At <NUM>, the wireless station transmits, to the access point, an add link request. The add link request indicates a MAC address associated with a link, a new MLD MAC address sequence number offset, and a timing synchronization function (TSF) of an update to the MAC address. The add link request is a robust add link request. Note that as used herein, the adjective "robust" refers to and/or describes a type of wireless communication that is configured to withstand technical faults, signal disturbances, and security threats. Thus, a robust add link request is an add link request that is configured to withstand technical faults, signal disturbances, and security threats. In some instances, the add link request may indicate an uplink traffic identifier (ID) and a downlink traffic ID. In some instances, the sequence number offset may be randomized.

The wireless station receives, from the access point, an add link response. The add link response indicates the MAC address associated with the link, the new MLD MAC address sequence number offset, and the TSF of the update to the MAC address. The add link response is a robust add link response. Note that as used herein, the adjective "robust" refers to and/or describes a type of wireless communication that is configured to withstand technical faults, signal disturbances, and security threats. Thus, a robust add link response is an add link response that is configured to withstand technical faults, signal disturbances, and security threats.

<FIG> illustrates a block diagram of an example of a method for selecting sequence number offsets for one or more sequence number spaces during an MLD parameters change, according to some embodiments. The method shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, this method may operate as follows.

At <NUM>, an access point, such as access point <NUM>, may receive, from a wireless station, such as wireless station <NUM>, a MAC protocol data unit (PDU) over a link with the wireless station (e.g., a non-AP MLD).

At <NUM>, the access point may determine whether parameters associated with the MAC PDU are parameters used prior to a parameters change time or parameters used after the parameters change time.

At <NUM>, in response to determining that the parameters are parameters used prior to the parameters change time, the access point may determine whether the MAC PDU was transmitted during a tolerance period associated with the parameters change time.

At <NUM>, in response to determining that the MAC PDU was transmitted during the tolerance period, the access point may determine a sequence number of the MAC PDU using a sequence number offset associated with the parameters used prior to the parameters change time.

In some instances, in response to determining that the MAC PDU was transmitted after the tolerance period, the access point may discard the MAC PDU. In some instances, in response to determining that the parameters are parameters used after the parameters change time, the access point may determine a sequence number of the MAC PDU using a sequence number offset associated with the parameters used after the parameters change time.

<FIG> illustrate block diagrams of examples of methods of operating an access point of an MLD, according to some embodiments. The methods shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired.

At <NUM>, an access point, such as access point <NUM>, may determine (e.g., based on a desired level of discoverability and/or a desired beacon mode) to operate in one of a plurality of operational modes. For example, in a first operational mode, the access point may be discoverable via any link of the MLD. As another example, in a second operational mode, the access point may be discoverable only on its primary channel. As a further example, in a third operational mode, the access point may be visible only to selected wireless stations that know the access point's beacon encryption key. As yet another example, in a fourth operational mode, the access point may be transitioning to an off phase and safely closing links.

At <NUM>, the access point may operate in a determined operational mode of the plurality of operational modes.

At <NUM>, an access point, such as access point <NUM>, may determine (e.g., based on a desired level of discoverability and/or a desired operational mode) to operate in one of a plurality of beacon modes. For example, in a first beacon mode, the access point may be discoverable via any link of the MLD. As another example, in a second beacon mode, the access point may be discoverable only on its primary channel. As a further example, in a third beacon mode, the access point may visible only to selected wireless stations that know the access point's beacon encryption key. As yet another example, in a fourth beacon mode, the access point may be transitioning to an off phase and safely closing links.

At <NUM>, the access point may operate in a determined beacon mode of the plurality of beacon modes.

<FIG> illustrates a block diagram of an example of a method for using a basic service set (BSS) transition management (BTM) query to add a new access point to an MLD, according to some embodiments. The method shown in <FIG> may be used in conjunction with any of the systems, methods, or devices shown in the Figures, among other devices. In various embodiments, some of the method elements shown may be performed concurrently, in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, this method may operate as follows.

At <NUM>, an access point, such as access point <NUM>, may associate with a wireless station. The access point may be included in a multi-link device (MLD).

At <NUM>, the access point may receive, from the wireless station, a BTM query. The BTM query may propose addition of a second access point to the MLD.

At <NUM>, the access point may send (or transmit), to the second access point, a start new access point (AP) in AP MLD request.

At <NUM>, the access point may receive, from the second access point, a new AP created response.

At <NUM>, the access point may send (or transmit), to the wireless station, a BTM request that includes a candidate BSS list. The candidate BSS list may include the second access point.

In some instances, the access point may receive, from the wireless device, an add link request and may send (or transmit) to the wireless device, an add link response. The add link response may indicate addition of the link to the second access point.

Other embodiments may be realized using one or more programmable hardware elements such as FPGAs.

In some embodiments, a wireless device may be configured to include a processor (and/or a set of processors) and a memory medium, where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to cause the wireless device to implement any of the various method embodiments described herein (or, any combination of the method embodiments described herein, or, any subset of any of the method embodiments described herein, or, any combination of such subsets). The device may be realized in any of various forms.

Claim 1:
A method for multilink scanning, comprising:
a wireless station (<NUM>),
associating (<NUM>) with an access point (<NUM>), wherein the access point (<NUM>) is comprised in a multi-link device, MLD;
transmitting (<NUM>), to the access point (<NUM>), a robust query request; and
receiving (<NUM>), from the access point (<NUM>), a robust query response, wherein the robust query response includes available access points (<NUM>) within the MLD and parameters associated with the MLD;
transmitting, to the access point (<NUM>), a robust add link request, wherein the add link request indicates a medium access control, MAC, address associated with a link, a new MLD MAC address sequence number offset, and a timing synchronization function, TSF, of an update to the MAC address; and
receiving, from the access point (<NUM>), a robust add link response, wherein the add link response indicates the MAC address associated with the link, the new MLD MAC address sequence number offset, and the TSF of the update to the MAC address; and
wherein the robust query request and the robust query response refer to wireless communications configured to withstand technical faults, signal disturbances, and security threats.