Non-simultaneous Transmit / Receive (NSTR) Soft Access Point (AP) Multi-Link Device (MLD)

Abstract

A wireless station (STA) operating as a non-simultaneous transmit / receive (NSTR) soft access point (AP) multilink device (MLD) associated with a primary link and a non-primary link determines that the non-primary link is unavailable and transmits a frame bearing an indication of the unavailability of the non-primary link only on the primary link. The NSTR softAP MLD may set a do not send (DNT) bit to a value of 1 and operate as a single-link device on the primary link based on the unavailability of the non-primary link. In some instances, the NSTR softAP MLD determines that the non-primary link is available while operating as a single-link device on the primary link, resets the DNT bit based on the availability of the non-primary link, and transmits the reset DNT bit in another frame only on the primary link.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims priority to U.S. Patent Application No. 17 / 409,370, entitled "NON-SIMULTANEOUS TRANSMIT-RECEIVE (NSTR) SOFT ACCESS POINT (AP) MULTI-LINK DEVICE (MLD)," filed August 23, 2021, and U.S. Patent Application No. 17 / 409,349, entitled "NON-SIMULTANEOUS TRANSMIT-RECEIVE (NSTR) SOFT ACCESS POINT (AP) MULTI-LINK DEVICE (MLD)," filed August 23, 2021, both of which are assigned to the assignee of the present application. The disclosures of all prior applications are deemed to be part of and incorporated by reference into this patent application.

[0002] The present disclosure relates generally to wireless communications, and more specifically, to wireless communications associated with a multi-link device (MLD). [Background technology]

[0003] 2. Description of Related Art A wireless local area network (WLAN) may be formed by one or more access points (APs) that provide a shared wireless communication medium for use by several client devices, also called stations (STAs). The basic building block of a WLAN, which conforms to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards, is the Basic Service Set (BSS) managed by the AP. Each BSS is identified by a Basic Service Set Identifier (BSSID) advertised by the AP. The AP periodically broadcasts beacon frames to enable any STA within wireless range of the AP to establish or maintain a communication link with the WLAN.

[0004] An AP multi-link device (MLD) may include multiple APs that can operate independently on multiple respective communication links. Each AP may establish a BSS on the respective communication links, and wireless communication devices associated with the AP MLD may transmit data to or receive data from the AP MLD on one or more of the communication links associated with the AP MLD. Each of the communication links may have various bandwidths by combining several 20 MHz wide channels together to form a 40 MHz wide channel, an 80 MHz wide channel, a 160 MHz wide channel, or a 320 MHz wide channel. Although the STA may have limited filtering capabilities that may allow the reception of data on one link to interfere with the transmission of data on another link, it may be desirable for the STA to operate as a softAP MLD. Summary of the Invention

[0005] The systems, methods, and devices of the present disclosure each have several inventive aspects, no single aspect of which is solely responsible for the desirable attributes disclosed herein. [Means for solving the problem]

[0006] One inventive aspect of the subject matter described in this disclosure may be implemented as a method of wireless communication by a wireless station (STA). In some implementations, the method includes operating as a non-simultaneous transmit-receive (NSTR) soft AP multilink device (MLD) including a first soft access point (AP) associated with a primary link and including a second AP associated with a non-primary link. The method includes determining that the non-primary link is unavailable. The method includes transmitting a frame bearing an indication of the unavailability of the non-primary link only on the primary link. The frame may be one of a beacon frame, a probe response frame, an association response frame, a reassociation response frame, or an action frame. In some instances, the frame includes a per-STA profile sub-element or a Reduced Neighbor Report (RNR) element including a Do Not Transmit (DNT) bit set to a value of 1, the DNT bit set to a value of 1 indicating unavailability of the non-primary link. In some cases, the frame includes a Capability Information field carrying a Critical Update Flag (CUF), where the CUF is set to a value of 1 based on the unavailability of a non-primary link.

[0007] In some implementations, the method may also include disabling the non-primary link or placing the non-primary link in a power saving state based on unavailability of the non-primary link. In some cases, disabling the non-primary link includes removing the non-primary link from a multi-link context associated with the NSTR softAP MLD. The method may also include determining that the non-primary link is available after removing the non-primary link from the multi-link context and adding the non-primary link to the multi-link context based on availability of the non-primary link. In some other cases, disabling the non-primary link includes remapping a traffic identifier (TID) from the non-primary link to the primary link. The method may also include determining that the non-primary link is available after disabling the non-primary link and remapping a TID from the primary link to the non-primary link based on availability of the non-primary link.

[0008] In some implementations, the method also includes operating as a single-link device on the primary link based on the unavailability of the non-primary links. In some instances, the method may also include, while operating as a single-link device on the primary link, determining that the non-primary links are available, resetting the DNT bit to a value of 0 based on the availability of the non-primary links, and transmitting a reset DNT bit in another frame only on the primary link, the other frame including a profile sub-element or a reduced neighbor report (RNR) element for each STA having a reset DNT bit with a value of 0. In some other implementations, the method also includes determining that the non-primary links are available after transmitting the indication, transmitting an indication of the availability of the non-primary links only on the primary link, and operating as a multi-link device on the primary link and the non-primary links based on the availability of the non-primary links.

[0009] In some implementations, the method may also include receiving a ready-to-send (RTS) frame from the STA MLD on the primary link, transmitting a CTS frame to the STA MLD on the primary link and the non-primary link based on receiving the RTS frame, and receiving one or more UL PPDUs from the STA MLD on the primary link and the non-primary link. In some other implementations, the method may also include switching the primary link from the first channel to the second channel simultaneously with switching the non-primary link from the second channel to the first channel. In some instances, the first channel is in one of the 5 GHz frequency band or the 6 GHz frequency band, and the second channel is in the other of the 5 GHz frequency band or the 6 GHz frequency band.

[0010] Another innovative aspect of the subject matter described in this disclosure may be implemented in a wireless communication device. In some implementations, the wireless communication device may include at least one modem, at least one processor communicatively coupled to the at least one modem, and at least one memory communicatively coupled to the at least one processor and storing processor-readable code. In some implementations, execution of the processor-readable code by the at least one processor in conjunction with the at least one modem may be configured to operate the wireless communication device as an NSTR softAP MLD including a first AP associated with a primary link and including a second AP associated with a non-primary link. The execution of the processor-readable code may be configured to determine that the non-primary link is unavailable. The execution of the processor-readable code may be configured to transmit a frame bearing an indication of the unavailability of the non-primary link only on the primary link. The frame may be one of a beacon frame, a probe response frame, an association response frame, a reassociation response frame, or an action frame. In some cases, the frame includes a per-STA profile sub-element or a reduced neighbor report (RNR) element that includes a do not send (DNT) bit set to a value of 1, the DNT bit set to a value of 1 indicating unavailability of the non-primary link. In some cases, the frame includes a capability information field that carries a critical update flag (CUF), the CUF set to a value of 1 based on unavailability of the non-primary link.

[0011] In some implementations, execution of the processor readable code may be configured to disable the non-primary link or place the non-primary link in a power saving state based on the non-primary link being unavailable. In some cases, disabling the non-primary link includes removing the non-primary link from a multi-link context associated with the NSTR softAP MLD. Execution of the processor readable code may also be configured to determine that the non-primary link is available after removing the non-primary link from the multi-link context and add the non-primary link to the multi-link context based on the availability of the non-primary link. In some other cases, disabling the non-primary link includes remapping a traffic identifier (TID) from the non-primary link to the primary link. Execution of the processor readable code may also be configured to determine that the non-primary link is available after disabling the non-primary link and remapping a TID from the primary link to the non-primary link based on the availability of the non-primary link.

[0012] In some implementations, execution of the processor readable code may also be configured to operate the wireless communications device as a single-link device on the primary link based on unavailability of the non-primary link. In some instances, execution of the processor readable code may also be configured to determine that the non-primary link is available while operating as a single-link device on the primary link, reset the DNT bit to a value of 0 based on the availability of the non-primary link, and transmit the reset DNT bit in another frame only on the primary link, the other frame including a profile sub-element or a reduced neighbor report (RNR) element for each STA that has the reset DNT bit with a value of 0. In some other implementations, execution of the processor readable code may also be configured to determine that the non-primary link is available after transmitting the indication, transmit an indication of the availability of the non-primary link only on the primary link, and operate as a multi-link device on the primary link and the non-primary link based on the availability of the non-primary link.

[0013] In some implementations, execution of the processor readable code may also be configured to receive an RTS frame from the STA MLD on the primary link, transmit a CTS frame to the STA MLD on the primary link and the non-primary link based on receiving the RTS frame, and receive one or more UL PPDUs from the STA MLD on the primary link and the non-primary link. In some other implementations, execution of the processor readable code may also be configured to switch the primary link from the first channel to the second channel simultaneously with switching the non-primary link from the second channel to the first channel. In some cases, the first channel is in one of the 5 GHz frequency band or the 6 GHz frequency band, and the second channel is in the other of the 5 GHz frequency band or the 6 GHz frequency band.

[0014] The details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. It should be noted that the relative dimensions of the following figures may not be drawn to scale. [Brief description of the drawings]

[0015] [Figure 1] 1 shows a pictorial diagram of an exemplary wireless communication network. [Figure 2A] 1 illustrates an exemplary protocol data unit (PDU) that may be used for communication between an access point (AP) and one or more wireless stations (STAs). [Figure 2B] 2B illustrates exemplary fields in the PDU of FIG. 2A. [Figure 3A] 4 illustrates another exemplary PDU that may be used for communication between an AP and one or more STAs. [Figure 3B] 4 illustrates another exemplary PDU that may be used for communication between an AP and one or more STAs. [Figure 4] 1 illustrates an exemplary physical layer convergence protocol (PLCP) protocol data unit (PPDU) that can be used for communication between an AP and several STAs. [Diagram 5] 1 illustrates a block diagram of an exemplary wireless communication device. [Figure 6A] 1 shows a block diagram of an exemplary access point (AP). [Figure 6B] 1 shows a block diagram of an exemplary station (STA). [Figure 7A] 1 illustrates a sequence diagram illustrating exemplary wireless communications supporting non-simultaneous transmit / receive (NSTR) soft access point (AP) multi-link device (MLD) in accordance with some implementations. [Figure 7B]1 shows a sequence diagram illustrating another example wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 8A] 1 shows a sequence diagram illustrating example wireless communications supporting NSTR softAP MLD according to some other implementations. [Figure 8B] 1 shows a sequence diagram illustrating another example wireless communication supporting NSTR softAP MLD according to some other implementations. [Figure 9A] 1 illustrates a timing diagram illustrating example wireless communications supporting NSTR softAP MLD, according to some implementations. [Figure 9B] 1 illustrates a timing diagram illustrating another example wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 10A] 1 illustrates an example management frame that can be used for multi-link communications, according to some implementations. [Figure 10B] 4 illustrates another example management frame that can be used for multi-link communications, according to some implementations. [Figure 11A] 1 illustrates example reduced neighbor reporting (RNR) elements that can be used for multi-link communications, according to some implementations. [Figure 11B] 11B illustrates an example TBTT information header of the RNR element of FIG. 11A according to some implementations. [Figure 11C] 11B illustrates an example TBTT information field of the RNR element of FIG. 11A according to some implementations. [Figure 12A] 1 illustrates example multilink (ML) elements that can be used for multilink communication, according to some implementations. [Figure 12B] 12B illustrates an example Multilink Control field of the ML element of FIG. 12A according to some implementations. [Figure 12C] 12B illustrates an example common information field of the ML element of FIG. 12A according to some implementations. [Figure 12D]12B illustrates an example Per-STA profile sub-element of the ML element of FIG. 12A according to some implementations. [Figure 12E] 12D illustrates an example STA control field of the Per-STA profile sub-element of FIG. 12D according to some implementations. [Figure 12F] 12D illustrates an example STA information field of the Per STA Profile sub-element of FIG. 12D according to some implementations. [Figure 13] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 14] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 15] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 16] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 17] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 18] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 19] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 20] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 21]1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 22] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Diagram 23] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 24] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Diagram 25] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 26] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 27] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 28] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 29] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Diagram 30] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Diagram 31]1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Diagram 32] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Diagram 33] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Diagram 34] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Diagram 35] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Diagram 36] 1 shows a flowchart illustrating an example process for wireless communication supporting NSTR softAP MLD, according to some implementations. [Figure 37] 1 shows a block diagram of an example wireless communication device according to some implementations. [Figure 38] 1 shows a block diagram of another example wireless communication device according to some implementations.

[0016] Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The following description is directed to several implementations for the purpose of describing the innovative aspects of the present disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in many different ways. The described implementations can be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals according to one or more of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, the IEEE 802.15 standard, the Bluetooth® standard defined by the Bluetooth Special Interest Group (SIG), or the Long Term Evolution (LTE), 3G, 4G, or 5G (New Radio (NR)) standards promulgated by the 3rd Generation Partnership Project (3GPP®), among others. The described implementations may be implemented in any device, system, or network capable of transmitting and receiving RF signals according to one or more of the following technologies or techniques: code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), single-user (SU) multiple-input multiple-output (MIMO), and multi-user (MU) MIMO.The described implementations may also be implemented using other wireless communications protocols or RF signals suitable for use in one or more of a wireless personal area network (WPAN), a wireless local area network (WLAN), a wireless wide area network (WWAN), or an internet of things (IOT) network.

[0018] Various implementations relate generally to communication between multilink devices (MLDs), such as AP MLDs and STA MLDs. Some implementations relate more specifically to wireless stations (STAs) operating as mobile hotspots on multiple communication links. The AP MLD includes multiple APs configured to communicate on multiple different communication links. The STA MLD may communicate with the AP MLD using one or more of the different communication links simultaneously. The AP MLD may provide a multilink context that includes or indicates a complete profile of the different communication links associated with the AP MLD. The complete profile of each link may include the capabilities, operating parameters, and discovery information of each link. The AP MLD may advertise the multilink context on one of its communication links, so that a nearby wireless communication device (such as a STA MLD) operating on that communication link can receive the multilink context and obtain a complete profile for the multiple communication links of the AP MLD. In this manner, a wireless communication device operating on one communication link can discover and associate with an AP MLD on one or more other communication links without scanning or probing the other communication links. The communication link for which the AP MLD advertises the multilink context may be referred to as a primary link, and the other communication links may be referred to as non-primary links.

[0019] The multilink context also enables the AP MLD and one or more associated devices to establish a common block acknowledgement (BA) policy or session over the multiple communication links of the AP MLD and to use a single authentication mechanism for the multiple communication links of the AP MLD. The associated devices can use the multilink context to dynamically switch communications between different communication links of the AP MLD without disassociating or reassociating with the AP MLD. The AP MLD can use the multilink context to dynamically change or remap the association between a traffic identifier (TID) value and each of the different communication links.

[0020] Compared to an AP, a wireless STA has limited filtering capabilities that may allow transmissions to a STA on one link to interfere with data transmissions from a STA on another link. For example, when a STA transmits downlink (DL) communications on one link while simultaneously receiving uplink (UL) communications on another link, the relatively small spacing between antenna resources of the STA, together with its limited filtering capabilities, may allow the transmission of DL data on one link to interfere with or prevent the simultaneous reception of UL data on the other link. This cross-link interference may inhibit or prevent a STA operating as a mobile hotspot on multiple communication links from simultaneously transmitting and receiving data on different communication links. Thus, these STAs may be referred to as non-simultaneous transmit / receive (NSTR) softAP MLD.

[0021] Aspects of the present disclosure recognize the importance of reducing or eliminating cross-link interference associated with NSTR softAP MLDs. In some implementations, the NSTR softAP MLDs associated with the primary link and the non-primary links may advertise complete profiles of the primary link and the non-primary links only on the primary link. The NSTR softAP MLD may also advertise updates to one or more BSS parameters of the primary link and the non-primary links only on the primary link. Advertising the complete profiles of both links of the NSTR softAP MLD on the primary link may enable some wireless communication devices operating on the primary link to discover and associate with the NSTR softAP MLD on one or both of the primary link and the non-primary link without scanning or probing the non-primary link. In some implementations, non-legacy devices operating on the primary link may be able to decode or parse the complete profiles of both the primary link and the non-primary link, while legacy devices operating on the primary link may be able to decode or parse only the complete profile of the primary link. As a result, legacy devices operating on the primary link may not be able to discover or associate with the NSTR softAP MLD on the non-primary link. Furthermore, by not advertising the complete profile of any link on the non-primary link, legacy devices operating on the non-primary link may not be able to discover or associate with the NSTR softAP MLD on the non-primary link. In this manner, various aspects of the subject matter disclosed herein may limit communications between the NSTR softAP MLD and legacy devices to the primary link.As used herein, the term "legacy device" may refer to a wireless communication device configured to operate in accordance with IEEE 802.11ax or an earlier amendment to the 802.11 family of wireless communications standards, and the term "non-legacy device" may refer to a wireless communication device configured to operate in accordance with IEEE 802.11be or a later amendment to the 802.11 family of wireless communications standards.

[0022] Various aspects of the subject matter described in this disclosure can be implemented to achieve one or more of the following potential advantages: By restricting communication between the NSTR softAP MLD and legacy devices to the primary link (and thereby preventing legacy devices from communicating with the NSTR softAP MLD on non-primary links), the NSTR softAP MLD may prevent legacy devices from transmitting UL data on non-primary links while the NSTR softAP MLD is transmitting DL data to one or more associated devices on the primary link. In this manner, implementations of the subject matter disclosed herein may reduce the likelihood that cross-link interference resulting from UL transmissions on non-primary links will degrade or otherwise interfere with DL transmissions from the NSTR softAP MLD on the primary link.

[0023] FIG. 1 illustrates a block diagram of an exemplary wireless communication network 100. According to some aspects, the wireless communication network 100 may be an example of a wireless local area network (WLAN), such as a Wi-Fi network (and hereinafter referred to as WLAN 100). For example, the WLAN 100 may be a network that implements at least one of the IEEE 802.11 family of standards (such as those defined by the IEEE 802.11-2016 specification or amendments thereto, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be). The WLAN 100 may include multiple wireless communication devices, such as an access point (AP) 102 and multiple stations (STAs) 104. Although only one AP 102 is shown, the WLAN network 100 may also include multiple APs 102.

[0024] Each of the STAs 104 may also be referred to as a mobile station (MS), mobile device, mobile handset, wireless handset, access terminal (AT), user equipment (UE), subscriber station (SS), or subscriber unit, among other possible examples. The STAs 104 may represent a variety of devices, such as a mobile phone, a personal digital assistant (PDA), other handheld device, a netbook, a notebook computer, a tablet computer, a laptop, a display device (e.g., a TV, a computer monitor, a navigation system, among others), a music or other audio or stereo device, a remote control device ("remote"), a printer, a kitchen appliance or other household appliance, a key fob (e.g., for a passive keyless entry and start (PKES) system), among other possible examples.

[0025] A single AP 102 and the associated set of STAs 104 may be referred to as a basic service set (BSS) managed by the respective AP 102. FIG. 1 additionally illustrates an example coverage area 106 of the AP 102, which may represent a basic service area (BSA) of the WLAN 100. The BSS may be identified to users by a service set identifier (SSID) and to other devices by a basic service set identifier (BSSID), which may be the medium access control (MAC) address of the AP 102. The AP 102 periodically broadcasts a beacon frame ("beacon") containing the BSSID to enable any STAs 104 within wireless range of the AP 102 to "associate" or reassociate with the AP 102 to establish or maintain a respective communication link 108 with the AP 102 (hereinafter also referred to as a "Wi-Fi link"). For example, the beacon may include an identification of a primary channel used by each AP 102, as well as timing synchronization functionality for establishing or maintaining timing synchronization with the AP 102. The APs 102 may provide access to external networks to various STAs 104 in the WLAN via their respective communication links 108.

[0026] To establish a communication link 108 with an AP 102, each of the STAs 104 is configured to perform passive or active scanning operations ("scans") on frequency channels in one or more frequency bands (e.g., the 2.4 GHz, 5.0 GHz, 6.0 GHz, or 60 GHz bands). To perform passive scanning, the STAs 104 listen for beacons, which are transmitted by the respective APs 102 at regular time intervals called target beacon transmission times (TBTTs) (measured in time units (TUs), where one TU may equal 1024 microseconds (μs)). To perform active scanning, the STAs 104 generate probe requests and transmit them continuously on each channel to be scanned, listening for probe responses from the APs 102. Each STA 104 may be configured to perform authentication and association operations to identify or select an AP 102 to associate with based on scanning information obtained through passive or active scanning, and establish a communication link 108 with the selected AP 102. The AP 102 assigns an association identifier (AID) to the STA 104 at the height of the association operation, which the AP 102 uses to track the STA 104.

[0027] As a result of the increasing ubiquity of wireless networks, a STA 104 may have the opportunity to select one of many BSSs within range of the STA or to select among multiple APs 102 that together form an extended service set (ESS) including multiple connected BSSs. The extended network stations associated with the WLAN 100 may be connected to a wired or wireless distribution system that may allow multiple APs 102 to be connected in such an ESS. Thus, a STA 104 may be covered by more than one AP 102 and may associate with different APs 102 at different times for different transmissions. Additionally, after association with an AP 102, the STA 104 may also be configured to periodically scan its surroundings to find a more suitable AP 102 to associate with. For example, a STA 104 moving with respect to its associated AP 102 may perform a "roaming" scan to find another AP 102 with more desirable network characteristics, such as a greater received signal strength indicator (RSSI) or a lower traffic load.

[0028] In some cases, the STAs 104 may form a network without involving the AP 102 or any other device other than the STAs 104 themselves. One example of such a network is an ad-hoc network (or wireless ad-hoc network). An ad-hoc network may alternatively be referred to as a mesh network or a peer-to-peer (P2P) network. In some cases, the ad-hoc network may be implemented within a larger wireless network, such as the WLAN 100. In such an implementation, the STAs 104 may be able to communicate with each other via the AP 102 using the communication link 108, but the STAs 104 may also communicate with each other directly via a direct wireless link 110. In addition, two STAs 104 may communicate via the direct communication link 110 regardless of whether both STAs 104 are associated with and served by the same AP 102. In such an ad-hoc system, one or more of the STAs 104 may assume the role filled by the AP 102 in the BSS. Such STAs 104 may be referred to as group owners (GOs) and may coordinate transmissions within the ad-hoc network. Examples of direct wireless links 110 include Wi-Fi direct connections, connections established by using Wi-Fi Tunneled Direct Link Setup (TDLS) links, and other P2P group connections.

[0029] The AP 102 and the STAs 104 may function and communicate (via their respective communication links 108) in accordance with the IEEE 802.11 family of standards (such as those defined by the IEEE 802.11-2016 specification or amendments thereto, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be). These standards define WLAN radio and baseband protocols for the PHY layer and the Medium Access Control (MAC) layer. The AP 102 and the STAs 104 transmit and receive wireless communications (hereinafter also referred to as "Wi-Fi communications") between each other in the form of Physical Layer Convergence Protocol (PLCP) Protocol Data Units (PPDUs). The APs 102 and STAs 104 in the WLAN 100 may transmit PPDUs over an unlicensed spectrum, which may be a portion of a spectrum that includes frequency bands traditionally used by Wi-Fi technology, such as the 2.4 GHz band, the 5.0 GHz band, the 60 GHz band, the 3.6 GHz band, and the 900 MHz band. Some implementations of the APs 102 and STAs 104 described herein may also communicate in other frequency bands, such as the 6.0 GHz band, which may support both licensed and unlicensed communications. The APs 102 and STAs 104 may also be configured to communicate over other frequency bands, such as shared licensed frequency bands, in which multiple operators may have licenses to operate in the same or overlapping frequency band or bands.

[0030] Each of the frequency bands may include multiple sub-bands or frequency channels. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, and 802.11ax standard revisions may be transmitted on the 2.4 and 5.0 GHz bands, each of which is divided into multiple 20 MHz channels. Thus, these PPDUs are transmitted over physical channels with a minimum bandwidth of 20 MHz, although larger channels may be formed through channel bonding. For example, PPDUs may be transmitted over physical channels with bandwidths of 40 MHz, 80 MHz, 160, or 320 MHz by bonding together multiple 20 MHz channels.

[0031] Each PPDU is a composite structure that includes a PHY preamble and a payload in the form of a PLCP service data unit (PSDU). Information provided in the preamble may be used by a receiving device to decode subsequent data in the PSDU. In instances where a PPDU is transmitted over bonded channels, the preamble field may be replicated and transmitted in each of the multiple constituent channels. The PHY preamble may include both a legacy portion (or "legacy preamble") and a non-legacy portion (or "non-legacy preamble"). The legacy preamble may be used for packet detection, automatic gain control, and channel estimation, among other applications. The legacy preamble may also generally be used to maintain compatibility with legacy devices. The format, coding, and information provided therein of the non-legacy portion of the preamble are based on the particular IEEE 802.11 protocol to be used to transmit the payload.

[0032] 2A illustrates an exemplary protocol data unit (PDU) 200 that may be used for communication between an AP and a number of STAs. For example, the PDU 200 may be configured as a PPDU. As illustrated, the PDU 200 includes a PHY preamble 202 and a PHY payload 204. For example, the PHY preamble 202 may include a legacy portion that itself includes a legacy short training field (L-STF) 206, a legacy long training field (L-LTF) 208, and a legacy signaling field (L-SIG) 210. The PHY preamble 202 may also include a non-legacy portion (not shown). The L-STF 206 generally enables a receiving device to perform automatic gain control (AGC) and coarse timing and frequency estimation. The L-LTF 208 generally enables a receiving device to perform fine timing and frequency estimation and also to estimate a wireless channel. The L-SIG 210 generally enables a receiving device to determine a duration of a PDU and to avoid transmitting on the PDU using the determined duration. For example, the L-STF 206, the L-LTF 208, and the L-SIG 210 may be modulated according to a binary phase shift keying (BPSK) modulation scheme. The payload 204 may be modulated according to a BPSK modulation scheme, a quadrature BPSK (Q-BPSK) modulation scheme, a quadrature amplitude modulation (QAM) modulation scheme, or another suitable modulation scheme. The payload 204 may generally carry upper layer data, for example, in the form of a medium access control (MAC) protocol data unit (MPDU) or an aggregated MPDU (A-MPDU).

[0033] 2B illustrates an example L-SIG field 220 in the PDU of FIG. 2A. The L-SIG 220 includes a data rate field 222, spare bits 224, a length field 226, parity bits 228, and a tail field 220. The data rate field 222 indicates a data rate (note that the data rate indicated in the data rate field 222 may not be the actual data rate of the data carried in the payload 204). The length field 226 indicates the length of the packet, e.g., in bytes. The parity bits 228 are used to detect bit errors. The tail field 220 includes tail bits that are used by a receiving device to terminate the operation of a decoder (e.g., a Viterbi decoder). The receiving device uses the data rate and length indicated in the data rate field 222 and length field 226 to determine the duration of the packet, e.g., in microseconds (μs).

[0034] 3A illustrates another exemplary PDU 300 usable for wireless communication between an AP and one or more STAs. The PDU 300 may be used for SU, OFDMA, or MU-MIMO transmissions. The PDU 300 may be formatted as a high-efficiency (HE) WLAN PPDU in accordance with the IEEE 802.11ax amendment to the IEEE 802.11 wireless communication protocol standard. The PDU 300 includes a PHY preamble including a legacy portion 302 and a non-legacy portion 304. The PDU 300 may further include a PHY payload 306 following the preamble, for example in the form of a PSDU including a data field 324.

[0035] The legacy portion 302 of the preamble includes an L-STF 308, an L-LTF 310, and an L-SIG 312. The non-legacy portion 304 includes a repetition of the L-SIG (RL-SIG) 314, a first HE signal field (HE-SIG-A) 316, an HE short training field (HE-STF) 320, and one or more HE long training fields (or symbols) (HE-LTF) 322. In the case of OFDMA or MU-MIMO communications, the second portion 304 further includes a second HE signal field (HE-SIG-B) 318 that is coded separately from the HE-SIG-A 316. In instances involving the use of a bonded channel, such as the L-STF 308, L-LTF 310, and L-SIG 312, the information in the RL-SIG 314 and HE-SIG-A 316 may be duplicated and transmitted in each of the component 20 MHz channels. In contrast, the content of HE-SIG-B318 is unique for each 20 MHz channel and may be targeted to specific STAs 104 .

[0036] The RL-SIG 314 may indicate to the HE-compatible STAs 104 that the PDU 300 is an HE PPDU. The AP 102 may use the HE-SIG-A 316 to identify and inform the STAs 104 that the AP has scheduled UL or DL ​​resources for the STAs 104. For example, the HE-SIG-A 316 may include a resource allocation subfield indicating the resource allocation for the identified STAs 104. The HE-SIG-A 316 may be decoded by each HE-compatible STA 104 served by the AP 102. In the case of MU transmissions, the HE-SIG-A 316 further includes information usable by each identified STA 104 to decode the associated HE-SIG-B 318. For example, the HE-SIG-A 316 may indicate a frame format including the location and length of the HE-SIG-B 318, the available channel bandwidth, and the modulation and coding scheme (MCS), among other examples. The HE-SIG-A 316 may also include HE WLAN signaling information usable by STAs 104 other than the identified STA 104 .

[0037] The HE-SIG-B 318 may carry STA-specific scheduling information, such as, for example, a STA-specific (or "user-specific") MCS value and STA-specific RU allocation information. In the context of DL MU-OFDMA, such information allows each STA 104 to identify and decode the corresponding resource unit (RU) in the associated data field 324. Each HE-SIG-B 318 includes a common field and at least one STA-specific field. The common field may indicate RU allocations for multiple STAs 104, including RU allocations in the frequency domain, which RUs are allocated for MU-MIMO transmissions, which RUs correspond to MU-OFDMA transmissions, and the number of users in the allocation, among other examples. The common field may be encoded with common bits, CRC bits, and tail bits. The user-specific fields may be assigned to a particular STA 104 and used to schedule specific RUs and indicate the scheduling to other WLAN devices. Each user-specific field may include multiple user block fields. Each user block field may include two user fields containing information for two respective STAs to decode the respective RU payloads in the data field 324.

[0038] 3B illustrates another exemplary PPDU 350 usable for wireless communication between an AP and one or more STAs. The PDU 350 may be used for SU transmission, OFDMA transmission, or MU-MIMO transmission. The PDU 350 may be formatted as an ultra-high throughput (EHT) WLAN PPDU according to the IEEE 802.11be amendment to the IEEE 802.11 wireless communication protocol standard, or as a PPDU compliant with any later (post-EHT) version of a new wireless communication protocol that complies with a future IEEE 802.11 wireless communication protocol standard or other wireless communication standard. The PDU 350 includes a PHY preamble that includes a legacy portion 352 and a non-legacy portion 354. The PDU 350 may further include a PHY payload 356 following the preamble, for example in the form of a PSDU that includes a data field 376.

[0039] The legacy portion 352 of the preamble includes an L-STF 358, an L-LTF 360, and an L-SIG 362. The non-legacy portion 354 of the preamble includes an RL-SIG 364 and a number of wireless communication protocol version dependent signal fields following the RL-SIG 364. For example, the non-legacy portion 354 may include a generic signal field 366 (referred to herein as “U-SIG 366”) and an EHT signal field 368 (referred to herein as “EHT-SIG 368”). One or both of the U-SIG 366 and EHT-SIG 368 may be structured as and carry version dependent information for other wireless communication protocol versions beyond EHT. The non-legacy portion 354 further includes an additional (referred to herein as “EHT-STF 372” although it may be constructed as and carry version dependent information for other wireless communication protocol versions beyond EHT) short training field 372 and one or more additional (referred to herein as “EHT-LTF 374” although it may be constructed as and carry version dependent information for other wireless communication protocol versions beyond EHT) long training fields 374. In instances involving the use of bonded channels, such as the L-STF 358, L-LTF 360, and L-SIG 362, the information in the U-SIG 366 and EHT-SIG 368 may be duplicated and transmitted in each of the constituent 20 MHz channels. In some implementations, the EHT-SIG 368 may additionally or alternatively carry information in one or more non-primary 20 MHz channels that are different from the information carried in the primary 20 MHz channel.

[0040] The EHT-SIG 368 may include one or more jointly coded symbols and may be coded in a different block than the block in which the U-SIG 366 is coded. The EHT-SIG 368 may be used by the AP to identify and inform the STAs 104 that the AP has scheduled UL or DL ​​resources for them. The EHT-SIG 368 may be decoded by each compatible STA 104 served by the AP 102. The EHT-SIG 368 may generally be used by a receiving device to interpret bits in the data field 376. For example, the EHT-SIG 368 may include RU allocation information, spatial stream configuration information, and per-user signaling information such as MCS, among other examples. The EHT-SIG 368 may further include a cyclic redundancy check (CRC) (e.g., 4 bits) and a tail (e.g., 6 bits), which may be used for a binary convolutional code (BCC). In some implementations, the EHT-SIG 368 may include one or more code blocks, each including a CRC and a tail, and in some aspects, each of the code blocks may be coded separately.

[0041] The EHT-SIG 368 may carry STA-specific scheduling information, such as, for example, a user-specific MCS value and user-specific RU allocation information. The EHT-SIG 368 may generally be used by a receiving device to interpret bits in the data field 376. In the context of DL MU-OFDMA, such information allows each STA 104 to identify and decode corresponding RUs in the associated data field 376. Each EHT-SIG 368 may include a common field and at least one user-specific field. The common field may indicate RU distribution to multiple STAs 104, indicate RU allocation in the frequency domain, indicate which RUs are allocated for MU-MIMO transmissions, which RUs correspond to MU-OFDMA transmissions, and the number of users in the allocation, among other examples. The common field may be encoded with common bits, CRC bits, and tail bits. The user-specific field may be assigned to a particular STA 104 and used to schedule specific RUs and indicate scheduling to other WLAN devices. Each user specific field may include multiple user block fields, and each user block field may include, for example, two user fields that store information for two respective STAs to decode the respective RU payloads.

[0042] The presence of RL-SIG 364 and U-SIG 366 may indicate to EHT or later version compliant STAs 104 that PPDU 350 is an EHT PPDU, or a PPDU that complies with any later (post-EHT) version of a new wireless communications protocol that complies with a future IEEE 802.11 wireless communications protocol standard. For example, U-SIG 366 may be used by a receiving device to interpret bits in one or more of EHT-SIG 368 or data field 376.

[0043] 4 illustrates an exemplary PPDU 400 that may be used for communication between an AP 102 and several STAs 104. As described above, each PPDU 400 includes a PHY preamble 402 and a PSDU 404. Each PSDU 404 may carry one or more MAC protocol data units (MPDUs), such as, for example, an aggregated MPDU (A-MPDU) 406 that includes multiple MAC MPDU subframes 408. Each MPDU subframe 408 may include a MAC delimiter 412 and a MAC header 414 prior to an associated frame body 416 that includes a data portion or "payload" of the MPDU subframe 408. The frame body 416 may carry one or more MAC service data units (MSDUs), such as, for example, an aggregated MSDU (A-MSDU) 422 that includes multiple MAC service data unit (MSDU) subframes 424. Each MSDU subframe 424 includes a corresponding MSDU 426 , which includes a subframe header 428 , a frame body 430 , and one or more padding bits 432 .

[0044] Referring again to the A-MPDU subframe 406, the MAC header 414 may include several fields that store information that defines or indicates characteristics or attributes of the data encapsulated within the frame body 416. The MAC header 414 also includes several fields that indicate addresses for the data encapsulated within the frame body 416. For example, the MAC header 412 may include a combination of a source address, a transmitter address, a receiver address, or a destination address. The MAC header 414 may include a frame control field that stores control information. The frame control field specifies the frame type, e.g., a data frame, a control frame, or a management frame. The MAC header 414 may further include a duration field that indicates a duration that extends from the end of the PPDU to the end of the acknowledgment (ACK) of the last PPDU to be transmitted by the wireless communication device (e.g., a block ACK (BA) in the case of A-MPDU). The use of the duration field serves to secure the wireless medium for the indicated duration, thus establishing the NAV. Each A-MPDU subframe 408 may also include a frame check sequence (FCS) field 418 for error detection. For example, the FCS field 418 may include a cyclic redundancy check (CRC) and may be followed by one or more padding bits 420.

[0045] As described above, the AP 102 and the STAs 104 can support multi-user (MU) communications, i.e., simultaneous transmissions from one device to each of multiple devices (e.g., multiple simultaneous downlink (DL) communications from the AP 102 to the corresponding STAs 104) or simultaneous transmissions from multiple devices to a single device (e.g., multiple simultaneous uplink (UL) transmissions from the corresponding STAs 104 to the AP 102). To support MU transmissions, the AP 102 and the STAs 104 may utilize multi-user multiple-input, multiple-output (MU-MIMO) and multi-user orthogonal frequency division multiple access (MU-OFDMA) techniques.

[0046] In a MU-OFDMA scheme, the available frequency spectrum of a wireless channel may be divided into multiple resource units (RUs), each including several different frequency subcarriers ("tones"). Different RUs may be allocated or assigned by the AP 102 to different STAs 104 at a particular time. The size and distribution of the RUs may be referred to as the RU allocation. In some implementations, the RUs may be allocated at 2 MHz intervals, so that the smallest RU may include 26 tones, consisting of 24 data tones and 2 pilot tones. As a result, in a 20 MHz channel, a maximum of 9 RUs (such as a 2 MHz, 26-tone RU) may be allocated (as some tones are reserved for other purposes). Similarly, in a 160 MHz channel, a maximum of 74 RUs may be allocated. Larger RUs of 52 tones, 106 tones, 242 tones, 484 tones, and 996 tones may also be allocated. For example, adjacent RUs may be separated by a null subcarrier (such as a DC subcarrier) to reduce interference between adjacent RUs, to reduce the DC offset of the receiver, and to avoid leakage of the transmit center frequency.

[0047] For UL MU transmissions, the AP 102 may transmit a trigger frame to initiate and synchronize UL MU-OFDMA or UL MU-MIMO transmissions from multiple STAs 104 to the AP 102. Such a trigger frame may thus enable multiple STAs 104 to transmit UL traffic to the AP 102 simultaneously in time. The trigger frame may address one or more STAs 104 via their respective association identifiers (AIDs) and may assign to each AID (and thus each STA 104) one or more RUs that may be used to transmit UL traffic to the AP 102. The AP may also designate one or more random access (RA) RUs for which non-scheduled STAs 104 may contend.

[0048] 5 shows a block diagram of an example wireless communication device 500. In some implementations, the wireless communication device 500 may be an example of a device for use in a STA, such as one of the STAs 104 described above with reference to FIG. 1. In some implementations, the wireless communication device 500 may be an example of a device for use in an AP, such as the AP 102 described above with reference to FIG. 1. The wireless communication device 500 is capable of transmitting (or outputting for transmission) and receiving wireless communications (e.g., in the form of wireless packets). For example, the wireless communication device 500 may be configured to transmit and receive packets in the form of Physical Layer Convergence Protocol (PLCP) Protocol Data Units (PPDUs) and Medium Access Control (MAC) Protocol Data Units (MPDUs) that conform to IEEE 802.11 standards, such as those defined by the IEEE 802.11-2016 specification or amendments thereof, including, but not limited to, 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be.

[0049] The wireless communication device 500 may be or include a chip, system on chip (SoC), chipset, package, or device including one or more modems 502, e.g., a Wi-Fi (IEEE 802.11 compliant) modem. In some implementations, the one or more modems 502 (collectively "modems 502") additionally include a WWAN modem (e.g., a 3GPP 4G LTE or 5G compliant modem). In some implementations, the wireless communication device 500 also includes one or more radios 504 (collectively "radios 504"). In some implementations, the wireless communication device 500 further includes one or more processors, processing blocks, or processing elements 506 (collectively "processors 506") and one or more memory blocks or memory elements 508 (collectively "memory 508").

[0050] The modem 502 may include an intelligent hardware block or device, such as, for example, an application-specific integrated circuit (ASIC), among other possible examples. The modem 502 is generally configured to implement a PHY layer. For example, the modem 502 is configured to modulate packets and output the modulated packets to the radio 504 for transmission over a wireless medium. The modem 502 is also configured to obtain modulated packets received by the radio 504 and demodulate the packets to provide demodulated packets. In addition to the modulator and demodulator, the modem 502 may further include digital signal processing (DSP) circuitry, an automatic gain control (AGC), a coder, a decoder, a multiplexer, and a demultiplexer. For example, while in a transmit mode, data obtained from the processor 506 is provided to a coder, which encodes the data to provide coded bits. The coded bits are then mapped to points in a modulation constellation (using a selected MCS) to provide modulated symbols. The modulated symbols are then NSS number of spatial streams or N STS The modulated symbols in each spatial or space-time stream may then be multiplexed and converted via an inverse fast Fourier transform (IFFT) block, followed by providing to a DSP circuit for Tx windowing and filtering. The digital signal may then be provided to a digital-to-analog converter (DAC). The resulting analog signal may then be provided to a frequency up-converter and ultimately to the radio 504. In an implementation involving beamforming, the modulated symbols in each spatial stream are precoded via a steering matrix prior to their provision to the IFFT block.

[0051] While in the receive mode, the digital signal received from the radio 504 is provided to the DSP circuitry, which is configured to acquire the received signal, for example, by detecting the presence of a signal and estimating an initial timing and frequency offset. The DSP circuitry is further configured to digitally condition the digital signal, for example, using channel (narrowband) filtering, analog impairment adjustment (such as to correct I / Q imbalance), and finally applying a digital gain to obtain a narrowband signal. The output of the DSP circuitry may then be provided to an AGC, which is configured to use information extracted from the digital signal in one or more received training fields, for example, to determine an appropriate gain. The output of the DSP circuitry is also coupled to a demodulator, which is configured to extract modulated symbols from the signal and calculate, for example, logarithm likelihood ratios (LLRs) for each bit position of each subcarrier in each spatial stream. The demodulator is coupled to a decoder, which may be configured to process the LLRs to provide decoded bits. The decoded bits from all of the spatial streams are then provided to a demultiplexer for demultiplexing, which may then be descrambled and provided to the MAC layer (processor 506) for processing, evaluation, or interpretation.

[0052] The radio 504 generally includes at least one radio frequency (RF) transmitter (or “transmitter chain”) and at least one RF receiver (or “receiver chain”), which may be combined into one or more transceivers. For example, the RF transmitter and RF receiver may each include various DSP circuitry including at least one power amplifier (PA) and at least one low-noise amplifier (LNA). The RF transmitter and RF receiver may then be coupled to one or more antennas. For example, in some implementations, the wireless communication device 500 may include or be coupled to multiple transmit antennas (each with a corresponding transmit chain) and multiple receive antennas (each with a corresponding receive chain). Symbols output from the modem 502 are provided to the radio 504, which then transmits the symbols via the coupled antenna. Similarly, symbols received via the antennas are obtained by the radio 504, which then provides the symbols to the modem 502.

[0053] The processor 506 may include an intelligent hardware block or device, such as, for example, a processing core, processing block, central processing unit (CPU), microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), programmable logic device (PLD) such as field programmable gate array (FPGA), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor 506 processes information received via the radio 504 and modem 502, and processes information output via the modem 502 and radio 504 for transmission over a wireless medium. For example, the processor 506 may implement a control plane and MAC layer configured to perform various operations related to the generation and transmission of MPDUs, frames, or packets. The MAC layer is configured to perform or facilitate frame coding and decoding, spatial multiplexing, space-time block coding (STBC), beamforming, and OFDMA resource allocation, among other operations or techniques. In some implementations, the processor 506 can generally control the modem 502 to cause the modem to perform various operations described above.

[0054] The memory 508 may include a tangible storage medium, such as a random-access memory (RAM) or a read-only memory (ROM) or a combination thereof. The memory 508 may also store non-transitory processor or computer executable software (SW) code that stores instructions that, when executed by the processor 506, cause the processor to perform various operations described herein for wireless communication, including generating, transmitting, receiving, and interpreting MPDUs, frames, or packets. For example, various functions of the components disclosed herein, or various blocks or steps of the methods, operations, processes, or algorithms disclosed herein, may be implemented as one or more modules of one or more computer programs.

[0055] FIG. 6A illustrates a block diagram of an exemplary AP 602. For example, the AP 602 may be an exemplary implementation of the AP 102 described with reference to FIG. 1. The AP 602 includes a wireless communication device (WCD) 610. For example, the wireless communication device 610 may be an exemplary implementation of the wireless communication device 500 described with reference to FIG. 5. The AP 602 also includes multiple antennas 620 coupled with the wireless communication device 610 for transmitting and receiving wireless communications. In some implementations, the AP 602 further includes an application processor 630 coupled with the wireless communication device 610 and a memory 640 coupled with the application processor 630. The AP 602 further includes at least one external network interface 650 that enables the AP 602 to communicate with a core network or a backhaul network to gain access to external networks, including the Internet. For example, the external network interface 650 may include one or both of a wired (e.g., Ethernet) network interface and a wireless network interface (such as a WWAN interface). Some of the above-mentioned components may communicate directly or indirectly with some of the other components via at least one bus. The AP 602 further includes a housing that contains the wireless communication device 610, the application processor 630, the memory 640, and at least a portion of the antenna 620 and the external network interface 650.

[0056] 6B illustrates a block diagram of an exemplary STA 604. For example, the STA 604 may be an exemplary implementation of the STA 104 described with reference to FIG. 1. The STA 604 includes a wireless communication device 615. For example, the wireless communication device 615 may be an exemplary implementation of the wireless communication device 500 described with reference to FIG. 5. The STA 604 also includes one or more antennas 625 coupled with the wireless communication device 615 for transmitting and receiving wireless communications. The STA 604 further includes an application processor 635 coupled with the wireless communication device 615 and a memory 645 coupled with the application processor 635. In some implementations, the STA 604 further includes a user interface (UI) 655 (e.g., a touch screen or a keypad) and a display 665 that may be integrated with the UI 655 to form a touch screen display. In some implementations, the STA 604 may further include one or more sensors 675, such as, for example, one or more inertial sensors, accelerometers, temperature sensors, pressure sensors, or altitude sensors. Some of the above-mentioned components may communicate directly or indirectly with other components via at least one bus. The STA 604 further includes a housing that contains the wireless communication device 615, the application processor 635, the memory 645, and at least a portion of the antenna 625, the UI 655, and the display 665.

[0057] As described, wireless STAs, compared to APs, may have limited filtering capabilities that may allow reception of UL data on one communication link to interfere with transmission of DL data on another communication link. As a result, a STA operating as an NSTR softAP MLD associated with a primary link and a non-primary link cannot simultaneously receive UL data on the non-primary link and transmit DL data on the primary link. Similarly, a STA operating as an NSTR softAP MLD cannot simultaneously receive UL data on the primary link and transmit DL data on the non-primary link.

[0058] Aspects of the present disclosure recognize the importance of reducing or eliminating cross-link interference associated with NSTR softAP MLDs. In some implementations, the NSTR softAP MLDs associated with the primary link and the non-primary links may advertise complete profiles of the primary link and the non-primary links only on the primary link. The NSTR softAP MLD may also advertise updates to one or more BSS parameters of the primary link and the non-primary links only on the primary link. Advertising the complete profiles of both links of the NSTR softAP MLD on the primary link may enable some wireless communication devices operating on the primary link to discover and associate with the NSTR softAP MLD on one or both of the primary link and the non-primary link without scanning or probing the non-primary link. In some implementations, non-legacy devices operating on the primary link may be able to decode or parse the complete profiles of both the primary link and the non-primary link, while legacy devices operating on the primary link may be able to decode or parse only the complete profile of the primary link. As a result, legacy devices operating on the primary link may not be able to discover or associate with the NSTR softAP MLD on the non-primary link. Furthermore, by not advertising the complete profile of any link on the non-primary link, legacy devices operating on the non-primary link may not be able to discover or associate with the NSTR softAP MLD on the non-primary link. In this manner, various aspects of the subject matter disclosed herein may limit communications between the NSTR softAP MLD and legacy devices to the primary link.

[0059] Various aspects of the subject matter described in this disclosure can be implemented to achieve one or more of the following potential advantages: By restricting communication between the NSTR softAP MLD and legacy devices to the primary link (and thereby preventing legacy devices from communicating with the NSTR softAP MLD on non-primary links), the NSTR softAP MLD may prevent legacy devices from transmitting UL data on non-primary links while the NSTR softAP MLD is transmitting DL data to one or more associated devices on the primary link. In this manner, implementations of the subject matter disclosed herein may reduce the likelihood that cross-link interference resulting from UL transmissions on non-primary links will degrade or otherwise interfere with DL transmissions from the NSTR softAP MLD on the primary link.

[0060] FIG. 7A illustrates a sequence diagram of an exemplary multi-link communication 700 according to some implementations. In the example of FIG. 7A, the multi-link communication 700 may be performed between a STA operating as an NSTR softAP MLD and one or more associated STAs (only one associated STA is shown for simplicity). The STAs may be any suitable wireless communication devices, including, for example, the STAs 104 and 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some implementations, the NSTR softAP MLD may include a first AP associated with a primary link and may include a second AP associated with a non-primary link. In some instances, the first and second APs may be softAPs implemented by the STA operating as an NSTR softAP MLD.

[0061] The NSTR softAP MLD may be configured to broadcast a complete profile of the primary link and the non-primary link in one or more frames transmitted only on the primary link. Thus, some wireless communication devices within range of the NSTR softAP MLD may obtain the complete profile of both the primary link and the non-primary link while operating on the primary link. Specifically, in some instances, non-legacy devices that obtain the complete profile of the primary link and the non-primary link may be able to associate with the NSTR softAP MLD on one or both of the primary link and the non-primary link, while legacy devices that receive the complete profile broadcasted on the primary link may be able to associate with the NSTR softAP MLD only on the primary link. In this manner, communication between the legacy devices and the NSTR softAP MLD may be restricted to the primary link, which in turn may reduce cross-link interference on the primary link caused by transmissions from legacy devices on the non-primary links.

[0062] In the example of FIG. 7A, the NSTR softAP MLD transmits a first frame including a complete profile of the primary link only on the primary link and indicating a complete profile of the non-primary link. In some implementations, the complete profile of each link may include at least a beacon interval, capability information, a service set identifier (SSID), supported rates, a timing synchronization function (TSF) value, and one or more additional fields or elements associated with discovery of the respective link. In some other implementations, the complete profile of each link may be defined to include all of the capabilities, operating parameters, and discovery information to be included in a beacon frame or probe response broadcast by an AP operating a BSS on the respective link.

[0063] In some implementations, the primary link may be configured as a complete BSS, and the non-primary links may be configured as pseudo-BSSs that share one or more capabilities and operational parameters with the primary link. For example, in some aspects, the non-primary links may have the same SSID, TSF value, and beacon interval as the primary link and thus inherit these values ​​from the primary link. As such, the SSID, TSF value, and beacon interval of the non-primary links may not be included in the first frame. In this manner, the size of the first frame may be reduced or minimized. Other capabilities and operational parameters of the non-primary links may differ from those of the primary link and therefore may not be inherited from the primary link. Examples of such capabilities and operational parameters include, but are not limited to, EDCA parameters, bandwidth, number of spatial streams (NSS), puncturing pattern, BSSID, and MLD capabilities.

[0064] The first frame may be any suitable frame that can carry or indicate a complete profile of both the primary link and the non-primary link. In some implementations, the first frame may be a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. In some cases, the NSTR softAP MLD may also transmit action frames, such as fast initial link setup (FILS) discovery frames, traffic indication map (TIM) frames, and notification frames, only on the primary link. The NSTR softAP MLD may also transmit group-addressed frames (such as multicast frames) only on the primary link. In this way, the NSTR softAP MLD may limit communication with legacy devices to the primary link.

[0065] In some implementations, the first frame includes a frame body including a number of fields and elements followed by a multilink (ML) element. The number of fields and elements may carry a complete profile of the primary link. The ML element may include a profile sub-element for each STA indicating a complete profile of the non-primary link. The ML element may further include a common information field carrying a BSS Parameters Change Count (BPCC) field indicating an update to one or more basic service set (BSS) parameters associated with the primary link. In some instances, one or more bits of a multilink control field or a common information field carried in the ML element may indicate whether the first frame is transmitted from a first AP of the NSTR softAP MLD. For example, one or more bits of a multilink control field or a common information field may be set to a first value to indicate that the first frame is transmitted from a first AP of the NSTR softAP MLD, or may be set to a second value to indicate that the first frame is transmitted from an AP associated with the AP MLD (or other simultaneous transmit-receive (STR) device).

[0066] The body of the first frame may also include a reduced neighbor report (RNR) element carrying a neighbor AP information field associated with the non-primary link. The neighbor AP information field may carry a target beacon transmission time (TBTT) information field consisting of a basic service set identity (BSSID) and one or more MLD parameters of the non-primary link. As described, the non-primary link may be configured as a pseudo-BSS that inherits some capabilities and operational parameters from the primary link, and thus the TBTT information field associated with the non-primary link may not include one or more subfields such as, but not limited to, the TBTT offset subfield, the shortened SSID subfield, the BSS parameters subfield, and the PSD subfield. The omission of these subfields may reduce the size or length of the TBTT information field in the neighbor AP information field associated with the non-primary link compared to the TBTT information field in the neighbor AP information field associated with the other communication link. Thus, the size or length of the TBTT information field in the neighbor AP information field associated with the non-primary link may be used by the receiving STA to determine whether the first frame is transmitted from the first AP of the NSTR softAP MLD. In some aspects, the TBTT information field associated with a non-primary link has a length of 9 octets, consisting of a 6-octet BSSID field and a 3-octet MLD parameters field.

[0067] In some implementations, the Neighbor AP Information field may include a TBTT information field type set to a value indicating that the Neighbor AP Information field only carries information associated with the non-primary link. In some cases, the Neighbor AP Information field may be a new or undefined type and the TBTT information field type may be set to 1 or a reserved value indicating a new or undefined type of the TBTT information field. In this manner, the receiving STA may determine that the first frame is transmitted from the first AP of the NSTR softAP MLD by parsing the TBTT information field type in the Neighbor AP Information field associated with the non-primary link. In some cases, non-legacy devices may recognize the new type of TBTT information field disclosed herein and thus obtain a complete profile of both the primary link and the non-primary link from the first frame. Conversely, legacy devices may not understand the new type of TBTT information field disclosed herein and therefore may ignore the TBTT information field in the Neighbor AP Information field associated with the non-primary link. In this manner, aspects of the subject matter disclosed herein may prevent at least some legacy devices from discovering the non-primary link based on information received on the primary link.

[0068] In some cases, the MLD parameters field of the TBTT information field may include a Basic Service Set (BSS) Parameter Change Count (BPCC) field carrying a value indicating an update to one or more Basic Service Set (BSS) parameters associated with the non-primary link, hi some other cases, the value indicating an update to one or more BSS parameters associated with the non-primary link may be carried in another suitable field, element, or header of the first frame.

[0069] The STA may receive a first frame transmitted by the NSTR softAP MLD on the primary link and parse the first frame to obtain a complete profile of the primary link and the non-primary link. The STA may use the complete profile of the primary link to discover or associate with the NSTR softAP MLD on the primary link, and may use the complete profile of the non-primary link to discover or associate with the NSTR softAP MLD on the non-primary link. In some cases, the STA may transmit a response frame on the primary link including capability information, operating parameters, and other information that may be used for association and authentication procedures with the NSTR softAP MLD. After the STA is associated with the NSTR softAP MLD on the primary link, the STA and the NSTR softAP MLD may exchange data, control signals, and other information with each other on the primary link. In an implementation in which the STA is a multi-radio device with STR capability, the STA may also associate with the NSTR softAP MLD on the non-primary link and exchange data, control signals, and other information with the NSTR softAP MLD on the non-primary link.

[0070] In some instances, one or more of the BSS parameters associated with the primary link may be changed or updated, and similarly, one or more of the BSS parameters associated with the non-primary links may be changed or updated. In some implementations, the BSS parameters for each communication link may be a Channel Switch Announcement (CSA) element, an extended Channel Switch Announcement (eCSA) element, Enhanced Distributed Channel Access (EDCA) parameters, a wait period element, a Direct Sequence Spread Spectrum (DSSS) parameter set, a high-throughput (HT) operation element, a very high-throughput (VHT) operation element, a high-efficiency (HE) operation element, an extremely high-throughput (EHT) operation element, a wideband channel switch element, an operation mode notification element, a broadcast Target Wait Time (TWT) element, a BSS color change announcement element, a Multi-User (MU) EDCA parameter set, a spatial reuse parameter set, or an uplink (UL) orthogonal frequency division multiple access (UL) parameter set. The OFDMA parameter set may include one or more of the following: UL OFDMA random access (UORA) parameter sets.

[0071] In some implementations, the NSTR softAP MLD may generate and transmit a second frame only on the primary link indicating an update to one or more BSS parameters of the primary link and an update to one or more BSS parameters of the non-primary links. Specifically, when the NSTR softAP MLD receives or determines an update to one or more BSS parameters of the primary link, the NSTR softAP MLD may increment a BPCC value associated with the primary link and insert the incremented BPCC value into a BPCC subfield in a common information field of an ML element carried in the second frame. When the NSTR softAP MLD receives or determines an update to one or more BSS parameters of a non-primary link, the NSTR softAP MLD may increment a BPCC value associated with the non-primary link and insert the incremented BPCC value into a BPCC subfield of an MLD parameters field in a neighbor AP information field of an RNR element carried in the second frame. In some cases, the NSTR softAP MLD may also set a Critical Update Flag (CUF) carried in the Capability Information field of the second frame based on incrementing the BPCC value associated with the non-primary link.

[0072] The STA may receive the second frame and parse the second frame to obtain BSS parameter updates for the primary link and the non-primary link. In some implementations, the second frame may be one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. In some cases, the second frame may include updated BSS parameters of one or both of the primary link and the non-primary link. In other implementations, the second frame may be an action frame, such as an announcement frame. In some aspects, the one or more updated BSS parameters of each communication link may be part of a partial profile of the respective communication link. For example, in some aspects, the NSTR softAP MLD may transmit an unsolicited broadcast probe response frame on the primary link carrying a partial profile of each communication link with the one or more updated BSS parameters. The STA may then transmit UL data to the NSTR softAP MLD on at least the primary link, and the NSTR softAP MLD may transmit DL data to the STA on at least the primary link.

[0073] FIG. 7B shows a sequence diagram illustrating another exemplary multi-link communication 710 according to some implementations. In the example of FIG. 7B, the multi-link communication 710 may be performed between the NSTR softAP MLD and one or more associated STAs (only one associated STA is shown for simplicity) described with reference to FIG. 7A. The NSTR softAP MLD may include a first AP associated with a primary link and may include a second AP associated with a non-primary link. In some cases, the first and second APs may be softAPs implemented by the STA operating as the NSTR softAP MLD.

[0074] As described with reference to Figure 7A, the NSTR softAP MLD may broadcast the complete profile of the primary link and the non-primary link only on the primary link. Broadcasting the complete profile of both links only on the primary link may allow non-legacy devices to discover and associate with the NSTR softAP MLD on one or both of the primary and non-primary links and may prevent legacy devices from discovering and associating with the NSTR softAP MLD on the non-primary links.

[0075] In some instances, the NSTR softAP MLD may determine that a non-primary link is unavailable. A non-primary link may be unavailable for multi-link communication between the NSTR softAP MLD and its associated STA for various reasons. For example, a non-primary link may be unavailable when the non-primary link is used for a cellular link in a long-term evolution (LTE) radio access network (RAN) or a fifth-generation (5G) new radio (NR) access network. In another example, a non-primary link may be unavailable when the non-primary link is placed in a power saving mode (including a sleep mode or a doze mode) to reduce power consumption or to extend the battery life of a STA operating as an NSTR softAP MLD. In another example, a non-primary link may be unavailable when the non-primary link is used for peer-to-peer (P2P) communication or intra-STA communication.

[0076] Aspects of the present disclosure recognize that a primary link may be more suitable to inform STAs associated with the NSTR softAP MLD of the unavailability of a non-primary link. In some implementations, the NSTR softAP MLD may generate a first frame including a Critical Update Flag (CUF) set to 1 and a Do Not Transmit (DNT) bit set to 1 based on the unavailability of a non-primary link. In some instances, the CUF may be carried in a capability information field of the first frame, and the DNT bit may be carried in a per-STA profile sub-element or an RNR element of the first frame.

[0077] The NSTR softAP MLD may transmit the first frame to the STA (and to other associated devices operating on the primary link) only on the primary link. In some implementations, the NSTR softAP MLD may operate as a single-link device on the primary link based on the unavailable non-primary link. For example, in some cases, the NSTR softAP MLD may place the softAP (or other transmit chain, receive chain, signal processing circuitry, etc.) associated with the non-primary link in a sleep, doze, or powered-off state while remaining fully operational on the primary link. In this single-link state, the NSTR softAP MLD may operate the BSS as a single-link BSS on the primary link while reducing (or nearly eliminating) the power consumption associated with operating on the non-primary link.

[0078] The STA may receive the first frame and analyze the first frame to obtain an indication that the non-primary link is unavailable. In some cases, the first frame may be one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. In other cases, the first frame may be an action frame, such as a notification frame. Although the NSTR softAP MLD operates as a single-link device on the primary link, the NSTR softAP MLD and its associated STAs may exchange frames with each other only on the primary link.

[0079] The non-primary link may become available while the NSTR softAP MLD operates as a single-link device on the primary link. The NSTR softAP MLD may determine that the non-primary link is available and may transmit an indication that the non-primary link is available. In some instances, the NSTR softAP MLD may reset the DNT bit associated with the non-primary link and transmit a second frame with at least the reset DNT bit only on the primary link. In some implementations, the NSTR softAP MLD may operate as a multi-link device on the primary link and the non-primary link based on determining that the non-primary link is available. For example, the NSTR softAP MLD may return the softAP (or other transmit chain, receive chain, signal processing circuitry, etc.) associated with the non-primary link to a fully operational state. In this multi-link state, the NSTR softAP MLD may operate the BSS on both the primary link and the non-primary link.

[0080] The STA may receive the second frame and analyze the second frame to obtain an indication that the non-primary link is available. In some cases, the second frame may be one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. In other cases, the second frame may be an action frame, such as a notification frame. The NSTR softAP MLD and its associated STAs may then exchange frames with each other on one or both of the primary and non-primary links.

[0081] In some implementations, determining the unavailability of the non-primary link may include or be associated with placing the non-primary link in a power saving state (including a sleep state or a doze state), which may reduce power consumption and extend the battery life of the NSTR softAP MLD. In some other implementations, determining the unavailability of the non-primary link may include or be associated with disabling the non-primary link. In some instances, the NSTR softAP MLD may disable the non-primary link by removing it from a multi-link context associated with the primary link and the non-primary link, thereby preventing the associated STAs of the NSTR softAP MLD from using the non-primary link. When the non-primary link becomes available, the NSTR softAP MLD may return or add the non-primary link to the multi-link context, thereby allowing the associated STAs of the NSTR softAP MLD to use the non-primary link (in addition to the primary link). In some aspects, the NSTR softAP MLD may transmit a first notification frame on the primary link to indicate that the non-primary link is no longer included in the multi-link context, and may transmit a second notification frame on the primary link to indicate that the non-primary link has been added to the multi-link context. In some other cases, the NSTR softAP MLD may disable the non-primary link by remapping a traffic identifier (TID) from the non-primary link to the primary link. When the non-primary link becomes available, the NSTR softAP MLD may remap the TID from the primary link to the non-primary link.In some aspects, the NSTR softAP MLD may transmit a first notification frame on the primary link to indicate that TIDs associated with the non-primary link have been remapped to the primary link, and may transmit a second notification frame on the primary link to indicate that some TIDs associated with the primary link have been remapped to the non-primary link.

[0082] FIG. 8A shows a sequence diagram illustrating an example multi-link communication 800 according to some other implementations. In the example of FIG. 8A, the multi-link communication 800 may be performed between an NSTR softAP MLD and one or more associated STAs (only one associated STA is shown for simplicity) described with reference to FIG. 7A and FIG. 7B. The NSTR softAP MLD may include a first AP associated with a primary link and may include a second AP associated with a non-primary link. In some cases, the first and second APs may be softAPs implemented by the STA operating as the NSTR softAP MLD.

[0083] As described, the NSTR softAP MLD may advertise the complete profile of both the primary link and the non-primary link in one or more frames transmitted only on the primary link. Thus, a non-legacy device may be able to discover the non-primary link while operating on the primary link, and a legacy device operating on either the primary link or the non-primary link may not be able to discover the non-primary link associated with the NSTR softAP MLD. In this manner, communication between the NSTR softAP MLD and the legacy device may be restricted to the primary link, which in turn may reduce the possibility of UL transmissions on the non-primary link while the NSTR softAP MLD is transmitting DL data to one or more associated devices on the primary link. This in turn may prevent or reduce cross-link interference on DL transmissions on the primary link resulting from simultaneous UL transmissions on the non-primary links.

[0084] As described, the NSTR softAP MLD may transmit a management frame only on the primary link that includes the complete profile of the primary link and indicates the complete profile of the non-primary link. The STA may receive the management frame and use the complete profile of the primary link to associate with and authenticate the NSTR softAP MLD on the primary link. In some cases, the STA may use the complete profile of the non-primary link to associate with and authenticate the NSTR softAP MLD on the non-primary link.

[0085] In some implementations, the NSTR softAP MLD may instruct the STA to exchange a ready-to-send (RTS) frame and a clear-to-send (CTS) frame with the NSTR softAP MLD before transmitting UL data to the NSTR softAP MLD. In some cases, the NSTR softAP MLD may transmit a frame including an instruction to perform an RTS / CTS frame exchange before transmitting UL data to the NSTR softAP MLD on the primary link. In some other cases, the NSTR softAP MLD may instruct the STA to perform an RTS / CTS frame exchange before transmitting UL data to the NSTR softAP MLD during association with the NSTR softAP MLD.

[0086] The STA receives the instruction. At a later time, such as when the STA has queued UL data to transmit, the STA may transmit an RTS frame to the NSTR softAP MLD on the primary link. The NSTR softAP MLD receives the RTS frame, determines that the non-primary link is available, and transmits a CTS frame to the STA on both the primary link and the non-primary link. The STA receives the CTS frame on both the primary link and the non-primary link, and determines that the non-primary link is available based on receiving the CTS frame on both the primary link and the non-primary link. The STA transmits one or more UL PPDUs to the NSTR softAP MLD on one or both of the primary link and the non-primary link. In some instances, transmitting a CTS frame to the STA on both the primary link and the non-primary link may enable the STA to link the non-primary link and the primary link together.

[0087] The NSTR softAP MLD may later determine that the non-primary link is unavailable. In some implementations, the NSTR softAP MLD may set the CUF equal to 1 and the DNT bit equal to 1 based on determining that the non-primary link is unavailable. In some cases, the NSTR softAP MLD may indicate the unavailability of the non-primary link by transmitting a CTS frame only on the primary link based on receiving an RTS frame from the STA. For example, when the STA has queued UL data, the STA transmits another RTS frame to the NSTR softAP MLD on the primary link. The NSTR softAP MLD receives the RTS frame and transmits a CTS frame only on the primary link to the STA based on the unavailability of the non-primary link. The STA receives the CTS frame and determines that the non-primary link is unavailable based on receiving the CTS frame only on the primary link. The STA transmits one or more UL PPDUs to the NSTR softAP MLD only on the primary link.

[0088] In some other implementations, the NSTR softAP MLD may perform a channel switching operation based on determining that the non-primary link is unavailable. For example, in some instances, the NSTR softAP MLD may switch the primary link from the first wireless channel to the second wireless channel at the same time as switching the non-primary link from the second wireless channel to the first wireless channel. In some aspects, the first wireless channel may be located in the 6 GHz frequency band, and the second wireless channel may be located in the 5 GHz frequency band. In other aspects, the first wireless channel may be located in the 5 GHz frequency band, and the second wireless channel may be located in the 6 GHz frequency band. In some other aspects, the first wireless channel may be located in one of the 2.4 GHz frequency band, the 5 GHz frequency band, or the 6 GHz frequency band, and the second wireless channel may be located in another one of the 2.4 GHz frequency band, the 5 GHz frequency band, or the 6 GHz frequency band.

[0089] The NSTR softAP MLD may use any suitable rule or mechanism to simultaneously switch channels of the primary link and the non-primary link. In some implementations, the NSTR softAP MLD may use a channel switch announcement (CSA) element or an extended channel switch announcement (eCSA) element carried in the body of a management frame (such as a beacon frame, a probe response frame, an association response frame, or a reassociation response frame) transmitted on the primary link when performing a channel switch operation.

[0090] FIG. 8B shows a sequence diagram illustrating another exemplary multi-link communication 810 according to some other implementations. In the example of FIG. 8B, the multi-link communication 810 may be performed between the NSTR softAP MLD and one or more associated STAs (only one associated STA is shown for simplicity) described with reference to FIG. 7A and FIG. 7B. The NSTR softAP MLD may include a first AP associated with a primary link and may include a second AP associated with a non-primary link. In some cases, the first and second APs may be softAPs implemented by the STA operating as the NSTR softAP MLD. As described, the NSTR softAP MLD may advertise the profiles of both the primary link and the non-primary link only on the primary link.

[0091] In some implementations, the NSTR softAP MLD transmits a first frame only on the primary link, the first frame including a complete profile of the primary link and MLD information common to the primary link and non-primary links. In some cases, the first frame may include a frame body including a number of fields and elements followed by an ML element. The number of fields and elements may carry a complete profile of the primary link. The ML element may consist of MLD common information. That is, the ML element carried in the first frame may not include link information related to non-primary links. In some cases, the MLD common information may include, but is not limited to, an MLD Medium Access Control (MAC) address field, a link ID information field, a BPCC field, a synchronization delay field, an Enhanced Multi-Link (EML) capability field, and an MLD capability field. The MLD MAC address field may include a MAC address of the NSTR softAP MLD. The BPCC field may indicate an update to one or more BSS parameters associated with the primary link.

[0092] The STA may receive a first frame transmitted on the primary link and parse the first frame to obtain the primary link complete profile and MLD common information. The STA may use the primary link complete profile to discover or associate with an NSTR softAP MLD on the primary link, and may use the MLD common information to determine whether to request a non-primary link complete profile from the AP MLD.

[0093] The STA transmits a second frame on the primary link that includes a request for a complete profile of the non-primary link. In some cases, the second frame can be a probe request frame. In other cases, the second frame can be an association request frame. In some other cases, the second frame can be a reassociation request frame.

[0094] The NSTR softAP MLD receives the second frame and parses the request for a complete profile of the non-primary link. In response to the request, the NSTR softAP MLD transmits a third frame indicating a complete profile of the non-primary link only on the primary link. In some implementations, the body of the third frame may include an ML element and an RNR element. The ML element may carry a profile sub-element for each STA indicating a complete profile of the non-primary link. The RNR element may include a Neighbor AP Information field associated with the non-primary link, which consists of the BSSID of the non-primary link and one or more MLD parameters. In some cases, the MLD parameters field of the TBTT information field carried in the Neighbor AP Information field may include a PBCC field carrying a value indicating whether any of the BSS parameters of the non-primary link have been updated. In some other cases, the value indicating whether any of the BSS parameters of the non-primary link have been updated may be carried in another suitable field, element, or header of the third frame.

[0095] As described with reference to FIG. 7A, the primary link may be configured as a full BSS, and the non-primary links may be configured as pseudo-BSSs that share at least some capabilities and operational parameters with the primary link. In some cases, the non-primary links may have the same SSID, TSF value, and beacon interval as the primary link and may inherit these values ​​from the primary link. The non-primary links may also inherit the TBTT offset, shortened SSID, BSS parameters, and PSD limitations of the primary link. Thus, the TBTT offset, shortened SSID, BSS parameters, and PSD subfields may not be present in the TBTT information field carried in the Neighbor AP Information field associated with the non-primary links, thereby reducing the length or size of the corresponding RNR element.

[0096] In various implementations, the first frame may be a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. The second frame may be a probe request frame, an association request frame, or a reassociation request frame. The third frame may be a probe response frame, an association response frame, or a reassociation response frame.

[0097] FIG. 9A illustrates a timing diagram of an exemplary multi-link communication 900 according to some implementations. In the example of FIG. 9A, the multi-link communication 900 may be performed between the NSTR softAP MLD described with reference to FIG. 7A, FIG. 7B, FIG. 8A, or FIG. 8B and two associated wireless stations STA1 and STA2. The STAs may be any suitable wireless communication devices, including, for example, the STAs 104 and 604 described above with reference to FIG. 1 and FIG. 6B, respectively. The NSTR softAP MLD may include a first AP associated with a primary link and may include a second AP associated with a non-primary link. In some cases, the first and second APs may be softAPs implemented by the STAs operating as the NSTR softAP MLD. In some implementations, STA1 is a legacy device configured to operate in accordance with IEEE 802.11ax or an earlier amendment to the 802.11 family of wireless communications standards, and STA2 is a non-legacy device configured to operate in accordance with IEEE 802.11be or a later amendment to the 802.11 family of wireless communications standards.

[0098] Time t 0 Prior to this, the NSTR softAP MLD contends for channel access to the primary link using a suitable channel access mechanism (such as an EDCA mechanism) and obtains a transmission opportunity (TXOP) on the primary link. After obtaining a TXOP on the primary link, the NSTR softAP MLD may also acquire channel access to the non-primary links. In some instances, obtaining channel access to the non-primary links may be based on obtaining channel access or a TXOP on the primary link. In some implementations, the NSTR softAP MLD may restrict transmissions on the non-primary links to individually addressed frames.

[0099] Time t 0In the NSTR softAP MLD, the first beacon frame 901 is transmitted only on the primary link, including the complete profile of the primary link and indicating the complete profile of the non-primary links. The primary link may be configured as a complete BSS, and the non-primary links may be configured as pseudo-BSSs that inherit one or more capabilities and operational parameters from the primary link. For example, in some aspects, the non-primary links may inherit the SSID, TSF value, and beacon interval from the primary link.

[0100] The beacon frame 901 includes a frame body including a number of fields and elements followed by an ML element. The number of fields and elements may carry a complete profile of the primary link. The ML element may carry a profile sub-element for each STA indicating a complete profile of the non-primary link. The ML element may include a common information field carrying a BPCC field indicating an update to one or more BSS parameters associated with the primary link. In some instances, one or more bits of a multilink control field or common information field carried in the ML element may indicate whether the first beacon frame 901 is transmitted from a first AP of the NSTR softAP MLD. For example, one or more bits of a multilink control field or common information field may be set to a first value to indicate that the first beacon frame 901 is transmitted from a first AP of the NSTR softAP MLD or may be set to a second value to indicate that the first beacon frame 901 is transmitted from an AP associated with a simultaneous transmit / receive (STR) device (e.g., AP MLD).

[0101] The first beacon frame 901 may also include an RNR element carrying a Neighbor AP Information field associated with the non-primary link. The Neighbor AP Information field may carry a TBTT Information field consisting of a BSSID and one or more MLD parameters of the non-primary link. In some cases, the MLD parameters field of the TBTT information field may include a BPCC field carrying a value indicating an update to one or more BSS parameters associated with the non-primary link. In some other cases, the one or more values ​​indicating an update to one or more BSS parameters associated with the non-primary link may be carried in another suitable field, element, or header of the first beacon frame 901.

[0102] STA1 and STA2 may receive the first beacon frame 901 on the primary link and parse the first beacon frame 901 to obtain a complete profile of the primary link and the non-primary link. In some implementations, each of STA1 and STA2 may parse or decode the complete profile of the primary link contained in the fields and elements contained in the body of the first beacon frame 901. As a non-legacy device, STA2 may also be able to parse or decode the complete profile of the non-primary link indicated in the ML element of the first beacon frame 901. As a legacy device, STA1 may not be able to parse or decode one or more portions of the ML element contained in the first beacon frame 901 and therefore may not be able to obtain capabilities, operational parameters, and other discovery information associated with the non-primary link from the first beacon frame 901. STA1 may also not be able to parse or decode one or more portions of the RNR element contained in the first beacon frame 901. Thus, STA2 may be able to discover and associate with the NSTR softAP MLD on both the primary and non-primary links using information obtained from the first beacon frame 901, while STA1 may only discover and associate with the NSTR softAP MLD on the primary link using information obtained from the first beacon frame 901. In this manner, communications between the NSTR softAP MLD and STA1 (and other legacy devices associated with the NSTR softAP MLD) may be restricted to the primary link.

[0103] Time t 1In the example, the NSTR softAP MLD transmits a first DL PPDU 911 to STA1 on the primary link and simultaneously transmits a second DL PPDU 912 to STA2 on the non-primary link. In some instances, the NSTR softAP MLD may use a first group of antenna resources to transmit the DL PPDU 911 to a first group of STAs (e.g., STA1) on the primary link and may use a second group of antenna resources to transmit the DL PPDU 912 to a second group of STAs (e.g., STA2) on the non-primary link.

[0104] Time t 1 ~t 2 At time t , STA1 receives a first DL PPDU 911 on the primary link and STA2 receives a second DL PPDU 912 on the non-primary link. The simultaneous transmission of DL PPDUs 911 and 912 on the primary and non-primary links indicates that wireless communication devices (e.g., STA1 and STA2) associated with the NSTR softAP MLD are 1 ~t 2 In particular, the softAP may be prevented from transmitting UL data to the NSTR softAP MLD on the primary link and non-primary links.

[0105] In some cases, the NSTR softAP MLD uses a suitable channel access mechanism to obtain another TXOP on the primary link at time t 2 ~t 3 After obtaining a TXOP on the primary link, the NSTR softAP MLD may obtain channel access to the non-primary link and obtain a TXOP on the non-primary link. In some other cases, the NSTR softAP MLD may obtain a channel access to the non-primary link and obtain a TXOP on the non-primary link at time t 0 ~t 1 TXOPs acquired on the primary and non-primary links at time t 2 ~t 3In this case, the UE may not need to contend for channel access.

[0106] Time t 3 In the NSTR softAP MLD, the second beacon frame 902 transmits a second beacon frame 902 only on the primary link. In some implementations, the second beacon frame 902 may be similar to the first beacon frame 901, for example, by carrying a complete profile of the primary link and indicating a complete profile of the non-primary links. In some other implementations, the second beacon frame 902 may include less information than the first beacon frame 901. For example, in some cases, the second beacon frame 902 may carry or indicate a partial profile of one or both of the primary link and the non-primary links. In some other cases, the second beacon frame 902 may carry a complete or partial profile of the primary link and may not include capabilities or operational parameters of the non-primary links. In some implementations, the second beacon frame 902 may be similar to the first frame described with reference to FIG. 8B, for example, by carrying or indicating only the BSSID and MLD common parameters of the non-primary links.

[0107] Time t 4 At time t 4 ~t 5Aspects of the present disclosure recognize that cross-link interference resulting from the transmission of DL PPDU 921 on the primary link may cause a period of "deafness" on the non-primary link during which the NSTR softAP MLD may be unable to receive or properly decode UL transmissions on the non-primary link. In some implementations, the NSTR softAP MLD may cause the non-primary link to enter a deaf state 914 during the transmission of DL PPDU 921 on the primary link. When in the deaf state 914, the non-primary link may not be available for communication between the NSTR softAP MLD and its associated STAs. Specifically, in some aspects, STA2 (and other wireless communication devices associated with the NSTR softAP MLD) may not be permitted to transmit UL data on the non-primary link during the deaf state 914. In this way, UL transmissions that the NSTR softAP MLD may not be able to receive or properly decode due to cross-link interference resulting from transmission of the DL PPDU 921 on the primary link may be prevented or delayed until after the DL transmission has ended.

[0108] The def state 914 may be of any suitable duration. In some cases, the duration of the def state 914 may be aligned in time with the transmission duration of the DL PPDU 921 on the primary link. In some other cases, the duration of the def state 914 may include a guard time followed by the transmission duration of the DL PPDU 921 followed by another guard time. Other durations may be suitable for the def state 914. In some implementations, the guard time may be selected to prevent (or reduce by more than a certain amount) the impact of cross-link interference on DL communications transmitted on non-primary links. For example, in some cases, the duration of the guard time may be configured to ensure that the first and last symbols of the DL PPDU 921 do not interfere with UL transmissions on non-primary links.

[0109] After completing the transmission of the DL PPDU 921, the NSTR softAP MLD restores the non-primary link from the def state 914. The NSTR softAP MLD may restore the non-primary link from the def state 914 using any suitable def restoration rule or mechanism. In some implementations, the NSTR softAP MLD may transmit an indication of the availability of the non-primary link on the primary link based on restoring the non-primary link. In implementations where the NSTR softAP MLD removed the non-primary link from the multi-link context when the non-primary link was placed in the def state 914 (and thus made unavailable), restoring the non-primary link from the def state 914 may include adding the non-primary link to the multi-link context. In some aspects, the NSTR softAP MLD may transmit a notification frame on the primary link to indicate that the non-primary link has been added to the multi-link context. In an implementation in which the NSTR softAP MLD remapped TIDs from the non-primary link to the primary link when the non-primary link was placed in the def state 914 (and thus made unavailable), bringing the non-primary link out of the def state 914 may include remapping TIDs from the primary link to the non-primary link. In some aspects, the NSTR softAP MLD may transmit a notification frame on the primary link to indicate that some TIDs belonging to the primary link have been remapped to the non-primary link.

[0110] Time t 6 At time t, STA1 transmits a UL PPDU 922 to the NSTR softAP MLD on the primary link, and STA2 transmits a UL PPDU 923 to the NSTR softAP MLD on the non-primary link. 6 ~t 7The simultaneous transmission of UL PPDUs 922 and 923 on the primary and non-primary links is performed by the NSTR softAP MLD at time t 6 ~t 7 t 6 ~t 7 This may eliminate the need to place non-primary links in a differential state.

[0111] In some cases, the NSTR softAP MLD uses a suitable channel access mechanism to obtain another TXOP on the primary link at time t 7 ~t 8 After obtaining a TXOP on the primary link, the NSTR softAP MLD may gain channel access to the non-primary link and obtain a TXOP on the non-primary link.

[0112] Time t 8 In the NSTR softAP MLD, the third beacon frame 903 is transmitted only on the primary link. In some implementations, the third beacon frame 903 may be similar to the first beacon frame 901, for example, by carrying a complete profile of the primary link and indicating a complete profile of the non-primary link. In some other implementations, the third beacon frame 903 may be similar to the second beacon frame 902, for example, by carrying less information than the first beacon frame 901.

[0113] Time t 9 At time t 9 ~t 10In response, the NSTR softAP MLD receives a UL PPDU 931 on the primary link. Aspects of the present disclosure recognize that cross-link interference resulting from the transmission of the UL PPDU 931 on the primary link may interfere with DL transmissions on the non-primary links. In some implementations, the NSTR softAP MLD places the non-primary links in a diff state 932 during the transmission of the UL PPDU 931 on the primary link. When in the diff state 931, the non-primary links may not be available for communication between the NSTR softAP MLD and its associated STAs. In some implementations, the NSTR softAP MLD may not transmit DL data on the non-primary links during the diff state 932. In this manner, DL transmissions on the non-primary links that are susceptible to cross-link interference resulting from the transmission of the UL PPDU 931 on the primary link may be prevented or delayed until after the end of the diff state 932. In some instances, STA2 (and other wireless communication devices associated with the NSTR softAP MLD) may not be permitted to transmit UL data on the non-primary link during the diff state 932.

[0114] The def state 932 may be of any suitable duration. In some cases, the duration of the def state 932 may be aligned in time with the transmission duration of the UL PPDU 931 on the primary link. In some other cases, the duration of the def state 932 may include a guard time followed by the transmission duration of the UL PPDU 931 followed by another guard time. Other durations may be suitable for the def state 932. In some implementations, the guard time may be selected to prevent (or reduce by more than a certain amount) the impact of cross-link interference on DL communications transmitted on the non-primary links. For example, in some cases, the duration of the guard time may be configured to ensure that DL transmissions on the non-primary links do not interfere with the first or last symbols of the UL PPDU 931. After the end of the transmission of the UL PPDU 931 or the expiration of the def state 932, the NSTR softAP MLD brings the non-primary links out of the def state 932.

[0115] FIG. 9B shows a timing diagram illustrating an example multi-link communication 940 according to some other implementations. In some implementations, the multi-link communication 940 may be performed between the NSTR softAP MLD described with reference to FIG. 9A and wireless stations STA1 and STA2. In some other implementations, the multi-link communication 940 may be performed between the NSTR softAP MLD described with reference to FIG. 7A, FIG. 7B, FIG. 8A, or FIG. 8B and associated wireless stations STA1 and STA2. The STAs may be any suitable wireless communication devices, including, for example, the STAs 104 and 604 described above with reference to FIG. 1 and FIG. 6B, respectively. The NSTR softAP MLD may include a first AP associated with a primary link and may include a second AP associated with a non-primary link. In some cases, the first and second APs may be soft APs implemented by the STAs operating as the NSTR softAP MLD. As described, STA1 is a legacy device configured to operate in accordance with IEEE 802.11ax or an earlier amendment to the 802.11 family of wireless communications standards, and STA2 is a non-legacy device configured to operate in accordance with IEEE 802.11be or a later amendment to the 802.11 family of wireless communications standards.

[0116] Time t 0 Prior to this, the NSTR softAP MLD contends for channel access to the primary link using a suitable channel access mechanism (such as an EDCA mechanism) and obtains a TXOP on the primary link. After obtaining a TXOP on the primary link, the NSTR softAP MLD may also acquire channel access to the non-primary links. In some instances, obtaining channel access to the non-primary links may be based on obtaining channel access or a TXOP on the primary link. In some implementations, the NSTR softAP MLD may restrict transmissions on the non-primary links to individually addressed frames.

[0117] Time t 0 In the above, the NSTR softAP MLD transmits a first beacon frame 941 only on the primary link. The first beacon frame 941 may include a complete profile of the primary link and may indicate a complete profile of the non-primary links. As described, the primary link may be configured as a complete BSS and the non-primary links may be configured as pseudo-BSSs that inherit one or more capabilities and operational parameters from the primary link. For example, in some aspects, the non-primary links may have the same SSID, TSF value, and beacon interval as the primary link and may inherit the SSID, TSF value, and beacon interval from the primary link.

[0118] In some implementations, the first beacon frame 941 may be similar to the first beacon frame 901 of FIG. 9A. That is, the first beacon frame 941 may include a frame body including a number of fields and elements followed by an ML element. The number of fields and elements may carry a complete profile of the primary link. The ML element may carry a profile sub-element for each STA indicating a complete profile of the non-primary link. The ML element may include a common information field carrying a BPCC field indicating an update to one or more BSS parameters of the primary link. One or more bits of the multilink control field or common information field carried in the ML element may indicate whether the first beacon frame 941 is transmitted from the first AP of the NSTR softAP MLD. The first beacon frame 941 may also include an RNR element carrying a neighbor AP information field associated with the non-primary link. The neighbor AP information field may carry a TBTT information field consisting of the BSSID and one or more MLD parameters of the non-primary link. In some cases, the MLD parameters field of the TBTT information field carried in the Neighbor AP Information field associated with the non-primary link may include a BPCC field carrying a value indicating an update to one or more BSS parameters of the non-primary link, hi some other cases, the value indicating an update to one or more BSS parameters of the non-primary link may be carried in another suitable field, element, or header of the first beacon frame 941.

[0119] STA1 and STA2 may receive the first beacon frame 941 on the primary link and parse the beacon frame 941 to obtain a complete profile of the primary link and the non-primary link. In some implementations, each of STA1 and STA2 may parse or decode the complete profile of the primary link contained in the fields and elements contained in the body of the first beacon frame 941. As a non-legacy device, STA2 may also be able to parse or decode the complete profile of the non-primary link indicated in the ML element of the first beacon frame 941. As a legacy device, STA1 may not be able to parse or decode one or more portions of the ML element contained in the first beacon frame 941 and therefore may not be able to obtain the capabilities, operating parameters, and other discovery information of the non-primary link from the first beacon frame 941. STA1 may also not be able to parse or decode one or more portions of the RNR element contained in the first beacon frame 941. Thus, STA2 may be able to discover and associate with the NSTR softAP MLD on both the primary and non-primary links using information obtained from the first beacon frame 941, while STA1 may only discover and associate with the NSTR softAP MLD on the primary link using information obtained from the first beacon frame 941. In this manner, communication between the NSTR softAP MLD and STA1 (and other legacy devices) may be restricted to the primary link.

[0120] Time t 1 In the NSTR softAP MLD, a first trigger frame 951 may be transmitted on the primary link simultaneously with transmitting a second trigger frame 952 on the non-primary link. The first trigger frame 951 may request UL transmissions from a first group of STAs (including STA1) on the primary link, and the second trigger frame 952 may request UL transmissions from a second group of STAs (including STA2) on the non-primary link.

[0121] Time t 2 ~t 3 Based on receiving the first trigger frame 951, STA1 transmits a trigger-based (TB) PPDU 961 to the NSTR softAP MLD on the primary link, and based on receiving the second trigger frame 952, STA2 transmits a TB PPDU 962 to the NSTR softAP MLD on the non-primary link. The simultaneous transmission of TB PPDUs 961 and 962 on the primary and non-primary links from STA1 and STA2, respectively, causes the NSTR softAP MLD to be inactive for time t 2 ~t 3 t 2 ~t 3 This may eliminate the need to place non-primary links in a differential state.

[0122] In some implementations, the NSTR softAP MLD may establish coordinated TWT sessions on the primary link and the non-primary link. Although not shown in FIG. 9B for simplicity, the TWT session on the primary link may include one or more service periods (SPs) during which the NSTR softAP MLD may schedule transmissions between STA1 or a first group of STAs on the primary link, and the TWT session on the non-primary link may include one or more SPs during which the NSTR softAP MLD may schedule transmissions between STA2 or a second group of STAs on the non-primary link. In some instances, the NSTR softAP MLD may synchronize the TWT SPs of the respective TWT sessions established on the primary link and the non-primary link with each other. For example, coordinating the respective TWT sessions or TWT SPs on the primary link and the non-primary link with each other may enable the NSTR softAP MLD to schedule the UL transmission of TB PPDU 961 from STA1 on the primary link simultaneously with the UL transmission of TB PPDU 962 from STA2 on the non-primary link. In this manner, the transmission of TB PPDU 961 from STA1 on the primary link may be time-aligned with the transmission of TB PPDU 962 from STA2 on the non-primary link.

[0123] In some cases, the NSTR softAP MLD uses a suitable channel access mechanism (such as an EDCA mechanism) for a time t 3 ~t 4 After obtaining a TXOP on the primary link, the NSTR softAP MLD may obtain channel access to the non-primary link and obtain a TXOP on the non-primary link. In some other cases, the NSTR softAP MLD may obtain channel access to the non-primary link and obtain a TXOP on the non-primary link at time t 0 ~t 1TXOPs acquired on the primary and non-primary links at time t 3 ~t 4 In this case, the UE may not need to contend for channel access.

[0124] Time t 4 In the NSTR softAP MLD, the second beacon frame 942 transmits a second beacon frame 942 only on the primary link. In some implementations, the second beacon frame 942 may be similar to the first beacon frame 941, for example, by carrying a complete profile of the primary link and indicating a complete profile of the non-primary links. In some other implementations, the second beacon frame 942 may include less information than the first beacon frame 941. For example, in some cases, the second beacon frame 942 may carry or indicate a partial profile of one or both of the primary link and the non-primary links. In some other cases, the second beacon frame 942 may carry a complete or partial profile of the primary link and may not include capabilities or operational parameters related to the non-primary links. In some implementations, the second beacon frame 942 may be similar to the first frame described with reference to FIG. 8B, for example, by carrying or indicating only the BSSID and MLD common parameters of the non-primary links.

[0125] Time t 5 At time t 6 ~t 7 At time t , STA2 transmits a TB PPDU 963 to the NSTR softAP MLD on the non-primary link based on receiving the third trigger frame 953. In the example of FIG. 9B, STA1 transmits a TB PPDU 963 to the NSTR softAP MLD on the non-primary link based on receiving the third trigger frame 953. 6 ~t 7The transmission of the UL PPDU 971 and the TB PPDU 963 on the primary link and the non-primary link from STA1 and STA2, respectively, occurs when the NSTR softAP MLD is notified at time t 6 ~t 7 t 6 ~t 7 This may eliminate the need to place non-primary links in a differential state.

[0126] In some implementations, the NSTR softAP MLD may establish an independent TWT session on the non-primary link to schedule transmissions of TB PPDUs 963 to the NSTR softAP MLD. Although not shown in FIG. 9B for simplicity, the independent TWT session on the non-primary link may include one or more SPs over which the NSTR softAP MLD may schedule UL transmissions from STA2 or DL ​​transmissions to STA2 (and other associated devices) on the non-primary link.

[0127] Time t 8 At time t 8 ~t 9 At time t, STA1 receives a first DL PPDU 981 on the primary link and STA2 receives a second DL PPDU 982 on the non-primary link. 8 ~t 9 t 8 ~t 9 The UL transmissions of the 10Gb / s may not see any cross-link interference resulting from the 10Gb / s UL transmissions.

[0128] In some implementations, the NSTR softAP MLD may establish coordinated TWT SPs on the primary and non-primary links to schedule transmission of DL PPDUs 981 and 982 to STA1 and STA2 on the primary and non-primary links, respectively. In this way, the NSTR softAP MLD may ensure that STA1 and STA2 are awake to receive transmission of DL PPDUs 981 and 982, respectively. In some instances, the TWT SPs on the non-primary links may be synchronized with the TWT SPs on the primary link such that DL transmissions on the primary and non-primary links are time-aligned with each other. In some instances, the NSTR softAP MLD may use a first group of antenna resources to transmit DL PPDU 981 to a first group of STAs (including STA1) on the primary link and may use a second group of antenna resources to transmit DL PPDU 982 to a second group of STAs (including STA2) on the non-primary link.

[0129] Time t 10 In the NSTR softAP MLD, the third beacon frame 943 is transmitted only on the primary link. In some implementations, the third beacon frame 943 may be similar to the first beacon frame 941, for example, by carrying a complete profile of the primary link and indicating a complete profile of the non-primary link. In some other implementations, the third beacon frame 943 may be similar to the second beacon frame 942, for example, by carrying less information than the first beacon frame 941.

[0130] Time t 11 At time t 11 ~t 12Aspects of the present disclosure recognize that cross-link interference resulting from the transmission of the UL PPDU 991 on the primary link may cause periods of deafness on the non-primary links. In some implementations, the NSTR softAP MLD may place the non-primary links in a deaf state 992 during the transmission of the UL PPDU 991 on the primary link. When in the deaf state 992, the non-primary links may not be available for communication between the NSTR softAP MLD and its associated STAs. In some implementations, the NSTR softAP MLD may not transmit DL data on the non-primary links during the deaf state 992. In this manner, DL transmissions on the non-primary links that are susceptible to cross-link interference resulting from the transmission of the UL PPDU 991 on the primary link may be prevented or delayed until after the end of the deaf state 992. In some instances, STA2 (and other wireless communication devices associated with the NSTR softAP MLD) may not be permitted to transmit UL data on the non-primary link during the def state 992.

[0131] The def state 992 may be of any suitable duration. In some cases, the duration of the def state 992 may be aligned in time with the transmission duration of the UL PPDU 991 on the primary link. In some other cases, the duration of the def state 992 may include a guard time followed by the transmission duration of the UL PPDU 991 followed by another guard time. Other durations may be suitable for the def state 992. In some implementations, the guard time may be selected to prevent (or reduce by more than a certain amount) the impact of cross-link interference on DL communications transmitted on the non-primary links. For example, in some cases, the duration of the guard time may be configured to ensure that DL transmissions on the non-primary links do not interfere with the first or last symbols of the UL PPDU 991. After the end of the transmission of the UL PPDU 991 or the expiration of the def state 992, the NSTR softAP MLD brings the non-primary links out of the def state 992.

[0132] FIG. 10A illustrates an exemplary management frame 1000A usable for wireless communication supporting NSTR softAP MLD, according to some implementations. The management frame 1000A may be a beacon frame, a probe response frame, an association response frame, a reassociation response frame, or some other suitable management frame. In some aspects, the management frame 1000A may be an exemplary implementation of the first or second frame of FIG. 7A, the first or second frame of FIG. 7B, the frame of FIG. 8A, the third frame of FIG. 8B, the beacon frame of FIG. 9A, or the beacon frame of FIG. 9B. For ease of explanation, some information elements of the frame 1000A may be referred to as "fields," "subfields," "elements," or "subelements," which may be considered interchangeable terms for the purposes of explanation herein.

[0133] The frame 1000A is shown to include a number of elements and fields 1010, a reduced neighbor report (RNR) element 1020, a capability and operational parameters 1030, and a basic multilink (ML) element 1040. The elements and fields 1010 may carry a complete profile of the primary link. The RNR element 1020 may include one or more AP entries 1022. Each of the AP entries 1022 may be associated with a respective AP of the AP MLD and may carry or indicate one or more parameters of the respective AP. In some implementations, the one or more parameters may include the BSSID and MLD parameters of the respective AP. In some instances, the respective AP entry 1022 may not include one or more of the TBTT offset, shortened SSID, BSS parameters, or PSD limits of the corresponding non-primary link. The capability and operational parameters 1030 may include any number of capability and operational parameters associated with the primary link. The ML element 1040 may include common information 1042 and several per-STA profile sub-elements 1044(1)-1044(n). The common information 1042 may include MLD parameters and other information common to the primary link and one or more non-primary links. Each of the per-STA profile sub-elements 1044(1)-1044(n) may be associated with a corresponding non-primary link of the AP MLD and may carry or represent a complete profile of the corresponding non-primary link.

[0134] 10B illustrates another exemplary management frame usable for multi-link communication with NSTR softAP MLD, according to some implementations. The management frame 1000B may be a beacon frame, a probe response frame, an association response frame, a reassociation response frame, or some other suitable management frame. In some aspects, the management frame 1000B may be an exemplary implementation of the first frame of FIG. 8B. For ease of explanation, some information elements of the frame 1000A may be referred to as "fields," "subfields," "elements," or "subelements," which may be considered interchangeable terms for the purposes of explanation herein.

[0135] The frame 1000B is shown to include a number of elements and fields 1010, an RNR element 1020, capabilities and operational parameters 1030, and a basic ML element 1050. The elements and fields 1010 may carry a complete profile of the primary link. The RNR element 1020 may include one or more AP entries 1022. Each of the AP entries 1022 may be associated with a respective AP of the AP MLD and may carry or indicate one or more parameters of the respective AP. In some implementations, the one or more parameters may include the BSSID and MLD parameters of the respective AP. In some instances, the respective AP entry 1022 may not include one or more of the TBTT offset, shortened SSID, BSS parameters, or PSD restrictions of the corresponding non-primary link. The capabilities and operational parameters 1030 may include any number of capabilities and operational parameters associated with the primary link. The ML element 1050 may include common information 1042. Common information 1042 may include MLD parameters and other information common to the primary link and one or more non-primary links associated with the AP MLD.

[0136] FIG. 11A illustrates an exemplary RNR element 1100 usable for multi-link communication according to some implementations. In some implementations, the RNR element 1100 may be an exemplary implementation of the RNR element 1020 of the exemplary management frames 1000A and 1000B described with reference to FIG. 10A and FIG. 10B, respectively. In some cases, the RNR element 1100 may be included in a frame, such as, but not limited to, a beacon frame, a probe response frame, an association response frame, or a reassociation response frame transmitted from an AP MLD. For ease of explanation, some information elements of the RNR element 1100 may be referred to as "fields," "subfields," "elements," or "subelements," which may be considered interchangeable terms for the purposes of explanation herein.

[0137] The RNR element 1100 may be used to indicate channel information, parameters, and other information pertaining to one or more APs participating in the AP MLD. As shown, the RNR element 1100 includes an element ID field 1102, a length field 1104, and one or more neighbor AP information fields 1106. The element ID field 1102 holds a value that identifies the RNR element 1100. The length field 1104 holds a value that indicates the length of the RNR element 1100. Each neighbor AP information field 1106 holds information that indicates the timing reference, operating class, channel number, and other parameters of the corresponding AP of the AP MLD.

[0138] As shown, the Neighbor AP Information field 1106 includes a TBTT Information Header 1111, an Operational Class field 1112, a Channel Number field 1113, and a TBTT Information Set field 1114. The TBTT Information Header 1111 carries general information about the corresponding AP. The Operational Class field 1112, together with the Channel Number field, indicates a channel start frequency that indicates the primary channel of the BSS of the AP associated with the Neighbor AP Information field. The Channel Number field 1113 indicates the last known primary channel of the AP associated with the Neighbor AP Information field. The TBTT Information Set field 1114 includes one or more TBTT Information fields that carry TBTT information, operational parameters, and MLD parameters for the AP associated with the Neighbor AP Information field.

[0139] In some implementations, the RNR element 1100 may be extended to include a Link ID field that stores one or more unique link IDs that may be used to map entries in the Neighbor AP Information field 1106 to information stored in the Per-STA Profile subelement of the ML element. In some other implementations, the RNR element 1100 may be extended to include a Do Not Send (DNT) field that may carry a DNT indication for the corresponding communication link. Additionally or alternatively, one or more elements or fields of the RNR element 1100 may be combined, added, removed, or modified.

[0140] FIG. 11B illustrates an example TBTT information header 1120 according to some implementations. In some instances, the TBTT information header 1120 may be an example implementation of the TBTT information header 1111 of FIG. 11A. As illustrated, the TBTT information header 1120 includes a TBTT information field type subfield 1121, a filtered neighbor AP subfield 1122, a reserved subfield 1123, a TBTT information count subfield 1124, and a TBTT information length subfield 1125. The TBTT information field type subfield 1121 carries a value indicating a type or format of the TBTT information field. In some implementations, the value of the TBTT information field type subfield 1121 may be set to 1 or a reserved value to indicate that the TBTT information field is a new type or format associated with an NSTR device. In this manner, a wireless communication device receiving an RNR element having a TBTT information field type subfield set to 1 or a reserved value can determine that a frame carrying the RNR element was transmitted by an NSTR device.

[0141] The Filtered Neighbor AP subfield 1122 is reserved except when the Reduced Neighbor Report element is included in the probe response frame transmitted by the TVHT AP. The Reserved subfield 1123 contains one or more reserved or unused bits. The TBTT Information Count subfield 1124 indicates the number of TBTT information fields included in the TBTT Information Set field of the Neighbor AP Information field minus one. The TBTT Information Length subfield 1125 indicates the length of each TBTT information field included in the TBTT Information Set field of the Neighbor AP Information field.

[0142] FIG. 11C illustrates an exemplary TBTT information field 1130 according to some implementations. In some instances, the TBTT information field 1130 may be one implementation of the TBTT information field carried in the TBTT information set field 1114 of FIG. 11A. As illustrated, the TBTT information field 1130 includes a neighboring AP TBTT offset subfield 1131, an optional BSSID subfield 1132, an optional shortened SSID subfield 1133, a BSS parameters subfield 1134, a 20MHz PSD subfield 1135, and an MLD parameters subfield 1136. The neighboring AP TBTT offset subfield 1131 indicates the offset (in TUs) of the next TBTT of the reported AP from the previous TBTT of the reporting AP. The optional BSSID subfield 1132 carries the BSSID of the reported AP. The optional shortened SSID subfield 1133 carries the shortened SSID of the reported AP. The BSS parameters subfield 1134 indicates one or more BSS parameters of the reported AP, such as, but not limited to, the OCT recommended subfield, the same SSID subfield, the multiple BSSID subfield, the transmitted BSSID subfield, the ESS member subfield, the unsolicited probe response active subfield, and the co-located AP subfield. The 20 MHz PSD subfield 1135 indicates the maximum transmit power for the corresponding AP on the primary 20 MHz channel. In some instances, the neighbor AP TBTT offset subfield 1131, the shortened SSID subfield 1133, the BSS parameters subfield 1134, and the 20 MHz PSD subfield 1135 may be omitted from the TBTT information field 1130.

[0143] The MLD parameters subfield 1136 includes an MLD ID subfield, a Link ID subfield, a BSS Parameter Change Count (BPCC) subfield, and a Reserved subfield. The MLD ID subfield indicates an identifier of the AP MLD and may be used to identify a list of reported APs associated with the AP MLD. The Link ID subfield indicates a link identifier of the corresponding AP and is unique to the corresponding AP. The BSS Parameter Change Count subfield is an unsigned integer initialized to 0 and increments when a significant update to the beacon frame of the reported AP occurs. The Reserved subfield includes one or more reserved or unused bits.

[0144] FIG. 12A illustrates an exemplary multi-link (ML) element 1200 usable for multi-link communication according to some implementations. In some implementations, the ML element 1200 may be an exemplary implementation of the ML element 1040 described with reference to FIG. 10A. In some cases, the ML element 1200 may be included in a frame, such as, but not limited to, a beacon frame, a probe response frame, an association response frame, or a reassociation response frame transmitted from an NSTR softAP MLD. For ease of explanation, some information elements of the ML element 1200 may be referred to as "fields," "subfields," "elements," or "subelements," which may be considered interchangeable terms for the purposes of explanation herein.

[0145] The ML element 1200 includes an element ID field 1201, a length field 1202, an element ID extension field 1203, a multilink control field 1204, a common information field 1205, and a link information field 1206. The element ID field 1201 and the element ID extension field 1203 hold values ​​indicating that the element 1200 is an ML element and a value indicating the type of ML element. The length field 1202 holds a value indicating the length of the ML element 1200. The multilink control field 1204 holds information indicating the presence of various fields and subfields within the common information field 1205. The common information field 1205 holds information common to one or more non-primary links associated with the AP MLD. The link information field 1206 holds information specific to each of the non-primary links associated with the AP MLD. In some instances, the link information field 1206 includes one or more per-STA profile sub-elements that may carry or indicate a complete profile of one or more corresponding non-primary links in an AP MLD, such as the NSTR softAP MLD.

[0146] FIG. 12B illustrates an exemplary multilink control field 1210 according to some implementations. In some instances, the multilink control field 1210 may be one implementation of the multilink control field 1204 of the ML element 1200 of FIG. 12A. As illustrated, the multilink control field 1210 includes a type field 1211, a reserved field 1212, and a presence bitmap field 1213. The type field 1211 is used to distinguish variants of the ML element 1200 (e.g., a basic ML element and a probe request ML element). The reserved field 1212 includes one or more reserved or unused bits. The presence bitmap field 1213 is used to indicate the presence of various subfields within the common information field 1205 of the ML element 1200. For example, the presence bitmap field 1213 may indicate the presence of an MLD MAC address field, a link ID information field, a BSS parameter change count (BPCC) field 1223, a media synchronization delay information field, an enhanced multilink (EML) capability field, and an MLD capability field in the common information field 1205 of the ML element 1200.

[0147] FIG. 12C illustrates an exemplary common information field 1220 according to some implementations. In some instances, the common information field 1220 may be one implementation of the common information field 1205 of the ML element 1200 of FIG. 12A. As illustrated, the common information field 1220 includes an MLD MAC address field 1221, a link ID information field 1222, a BPCC field 1223, a media synchronization delay information field 1224, an enhanced multilink (EML) capabilities field 1225, and an MLD capabilities field 1226. The MLD MAC address field 1221 holds the MAC address of the MLD (such as the NSTR softAP MLD). The link ID information field 1222 holds the link identifier of the AP transmitting the ML element 1200. The BSS parameter change count (BPCC) field 1223 holds an unsigned integer that is initialized to 0 and increments when a significant update occurs to the operational parameters of the AP transmitting the base variant ML element.

[0148] The Medium Sync Delay Information field 1224 carries a value indicating the duration of the MediumSyncDelay timer. The EML Capability field 1225 includes several subfields used to signal capabilities for EML Single-Radio (SR) and Multiple-Radio (MR) operations. The MLD Capability field 1226 indicates various capabilities of the MLD. In some instances, the MLD Capability field 1226 may indicate the maximum number of links that support simultaneous transmission or reception of frames, whether the MLD supports reception of frames carrying an SRS control subfield, whether the MLD supports TID-to-link mapping negotiation, and the minimum frequency gap between any two links recommended by non-AP MLD for STR operation.

[0149] FIG. 12D illustrates an exemplary per-STA profile sub-element 1230 according to some implementations. In some instances, the per-STA profile sub-element 1230 may be one implementation of the per-STA profile sub-element contained in the link info field 1206 of the ML element 1200 of FIG. 12A. As illustrated, the per-STA profile sub-element 1230 may include a sub-element ID field 1231, a length field 1232, a STA control field 1233, a STA information field 1234, and a STA profile field 1235. The sub-element ID field 1231 contains a value indicating the type of the per-STA profile sub-element 1230. The length field 1232 contains a value indicating the length of the per-STA profile sub-element 1230. The STA control field 1233 contains information indicating the presence (or absence) of various fields and sub-fields in the STA profile field 1235. The STA information field 1234 contains information related to the AP that corresponds to the per-STA profile sub-element 1230. The STA Profile field 1235 holds information indicating the complete profile of the AP that corresponds to the Per-STA Profile sub-element 1230 .

[0150] FIG. 12E illustrates an exemplary STA control field 1240 according to some implementations. In some instances, the STA control field 1240 may be an implementation of the STA control field 1233 of the Per STA profile sub-element 1230 of FIG. 12D. As illustrated, the STA control field 1240 includes a link ID field 1241, a complete profile field 1242, a MAC address present field 1243, a beacon interval present field 1244, a DTIM information present field 1245, an NSTR link pair present field 1246, an NSTR bitmap size field 1247, and a reserved field 1248. The link ID field 1241 carries a value that uniquely identifies a communication link associated with the AP that corresponds to the Per STA profile sub-element 1230. The complete profile field 1242 carries a value that indicates whether the Per STA profile sub-element 1230 carries a complete profile of the corresponding AP. The MAC address present field 1243 holds a value indicating whether the per STA profile sub-element 1230 holds a MAC address of the corresponding AP. The beacon interval present field 1244 holds a value indicating whether the STA information field 1234 of the per STA profile sub-element 1230 holds a beacon interval of the corresponding AP. The DTIM information present field 1245 holds a value indicating whether the STA information field 1234 of the per STA profile sub-element 1230 holds DTIM information of the corresponding AP. The NSTR link pair present field 1246 holds a value indicating whether the per STA profile sub-element 1230 holds information regarding a pair of communication links (e.g., a primary link and a non-primary link) associated with the NSTR softAP MLD. The NSTR bitmap size field 1247 holds a value indicating the size of the NSTR indication bitmap field included in the per STA profile sub-element 1230.

[0151] FIG. 12F illustrates an exemplary STA information field 1250 according to some implementations. In some instances, the STA information field 1250 may be an implementation of the STA information field 1234 of the per-STA profile sub-element 1230 of FIG. 12D. As illustrated, the STA information field 1250 includes a MAC address field 1251, a beacon interval field 1252, a DTIM field 1253, an NSTR link pair field 1254, and an NSTR bitmap field 1255. The MAC address field 1251 holds a MAC address of the AP corresponding to the per-STA profile sub-element 1230. The beacon interval field 1252 holds information indicating a beacon interval of the AP corresponding to the per-STA profile sub-element 1230. The DTIM field 1253 holds information indicating a DTIM count and a DTIM period of the AP corresponding to the per-STA profile sub-element 1230. The NSTR link pair field 1254 holds information identifying a pair of communication links associated with the AP corresponding to the per-STA profile sub-element 1230. The NSTR bitmap field 1255 holds the NSTR bitmap of the AP that corresponds to the Per-STA Profile subelement 1230 .

[0152] 13 is a flow chart illustrating an example process 1300 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 1300 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 1300 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 1300 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7A.

[0153] In some implementations, the process 1300 begins at block 1302 with operating as an NSTR softAP MLD associated with a primary link and a non-primary link. At block 1304, the process 1300 continues by transmitting a frame only on the primary link, the frame including a complete profile of the primary link and indicating a complete profile of the non-primary link, each of the respective complete profiles of the primary link and the non-primary link including at least a beacon interval, capability information, a service set identifier (SSID), supported rates, a timing synchronization function (TSF) value, and one or more additional fields or elements associated with discovery of the respective link. The frame is transmitted only on the primary link and may be one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. In some instances, the beacon interval, SSID, and TSF values ​​of the complete profile of the non-primary link are inherited from the complete profile of the primary link. Thus, the beacon interval, SSID, and TSF values ​​of the non-primary link may not be present in the frame.

[0154] In some implementations, the frame includes a frame body including a multilink (ML) element that includes multiple fields and elements carrying a complete profile of the primary link and carries per-STA profile sub-elements that indicate the complete profiles of the non-primary links. The ML element includes a common information field that carries a BPCC field that indicates updates to one or more BSS parameters associated with the primary link. One or more bits in the multilink control field or common information field of the ML element may indicate whether the frame is being transmitted from the first AP of the NSTR softAP MLD.

[0155] The frame body may also include an RNR element carrying a Neighbor AP Information field associated with a non-primary link. The Neighbor AP Information field may carry a TBTT information field consisting of the BSSID and one or more MLD parameters of the non-primary link. In some instances, the TBTT offset, abbreviated SSID, BSS parameters, and PSD parameters of the non-primary link may be inherited from the primary link. Thus, the TBTT offset subfield, abbreviated SSID subfield, BSS parameters subfield, and PSD subfield may be omitted from the TBTT information field in the Neighbor AP Information field associated with the non-primary link, thereby reducing the size and overhead of the RNR element. In some aspects, this reduced size TBTT information field may be a new type of TBTT information field that is not defined by any of the existing amendments to the 802.11 family of wireless communications standards. Thus, the Neighbor AP Information field may include a TBTT information field type set to a value indicating that the Neighbor AP Information field carries information related to only the non-primary link. In some cases, the TBTT information field type may be set to 1 or a reserved value to indicate this new or undefined type of TBTT information field. Setting the TBTT information field type to 1 or a reserved value may also indicate that the frame carrying the associated Neighbor AP Information field, and therefore the corresponding RNR element, is transmitted from an AP associated with the NSTR softAP MLD.

[0156] In some implementations, the length of the TBTT information field indicates whether the frame is being transmitted from the first AP of the NSTR softAP MLD. In some cases, the length of the TBTT information field is 9 octets. The one or more MLD parameters of the TBTT information field may include a BPCC field that indicates updates to one or more BSS parameters associated with the non-primary link.

[0157] 14 is a flow chart illustrating an example process 1400 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. For example, the process 1400 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 1400 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 1400 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7A.

[0158] In some implementations, the process 1400 may be performed after transmitting a frame at block 1304 of FIG. 13. For example, at block 1402, the process 1400 begins with receiving an update to at least one of the BSS parameters associated with a non-primary link. At block 1404, the process 1400 continues with incrementing a value of a BPCC field of a TBTT information field included in an RNR element of another frame based on the received update. At block 1406, the process 1400 continues with setting a Critical Update Flag (CUF) in a Capability Information field of the other frame based on incrementing the value carried in the BPCC field. At block 1408, the process 1400 continues with transmitting the other frame only on the primary link, the other frame indicating an update to at least one BSS parameter associated with the non-primary link. In some instances, the other frame may be an action frame, such as a beacon frame, a probe response frame, an association response frame, a reassociation response frame, or an announcement frame.

[0159] In some implementations, the BSS parameters may include at least one of a channel switch announcement (CSA) element, an extended channel switch announcement (eCSA) element, an enhanced distributed channel access (EDCA) parameter, a waiting period element, a direct sequence spread spectrum (DSSS) parameter set, a high throughput (HT) operation element, a very high throughput (VHT) operation element, a high efficiency (HE) operation element, an extremely high throughput (EHT) operation element, a wideband channel switch element, an operating mode notification element, a broadcast target latency (TWT) element, a BSS color change announcement element, a multi-user (MU) EDCA parameter set, a spatial reuse parameter set, or an uplink (UL) orthogonal frequency division multiple access (OFDMA) random access (UORA) parameter set.

[0160] FIG. 15 is a flow chart illustrating an example process 1500 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 1500 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 1500 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 1500 may be performed by an AP MLD, such as the NSTR softAP MLD described above with reference to FIG. 7A.

[0161] In various implementations, the process 1500 may be performed after transmitting a frame at block 1304 of FIG. 13. For example, at block 1502, the process 1500 begins with receiving an update to one or more BSS parameters associated with a non-primary link. At block 1504, the process 1500 continues with transmitting one or more updated BSS parameters associated with the non-primary link only on the primary link. In some implementations, the one or more updated BSS parameters may be carried in a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. In some other implementations, the one or more updated BSS parameters may be part of a partial profile of the non-primary link. In some instances, the NSTR softAP MLD may transmit an unsolicited broadcast probe response frame on the primary link carrying a partial profile of the non-primary link (and thus indicating one or more updated BSS parameters of the non-primary link).

[0162] FIG. 16 is a flow chart illustrating an example process 1600 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 1600 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 1600 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 1600 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0163] In some implementations, the process 1600 begins at block 1602 by operating as an NSTR softAP MLD associated with a primary link and a non-primary link. At block 1604, the process 1600 continues with determining that the non-primary link is unavailable. At block 1606, the process 1600 continues with transmitting a frame carrying an indication of the unavailability of the non-primary link only on the primary link. In some cases, the frame may be one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. In some other cases, the frame may be an action frame, such as a notification frame.

[0164] A non-primary link may be unavailable for various reasons. For example, a non-primary link may be unavailable for multi-link communication associated with an NSTR softAP MLD when the non-primary link is used for a cellular link in a Long Term Evolution (LTE) Radio Access Network (RAN) or a fifth generation (5G) New Radio (NR) access network. In another example, a non-primary link may be unavailable for multi-link communication associated with an NSTR softAP MLD when the non-primary link is placed in a power saving mode (including a sleep mode or a doze mode), for example, to reduce power consumption or to extend the battery life of the NSTR softAP MLD. In another example, a non-primary link may be unavailable for multi-link communication associated with an NSTR softAP MLD when the non-primary link is used for peer-to-peer (P2P) communication or intra-STA communication.

[0165] FIG. 17 is a flow chart illustrating an example process 1700 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 1700 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 1700 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 1700 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0166] In some implementations, the process 1700 may be performed in conjunction with sending the indication at block 1606 of FIG. 16. For example, at block 1702, the process 1700 begins with setting a do not send (DNT) bit to a value of 1 based on the unavailability of a non-primary link. In some cases, the DNT bit may be carried in a per-STA profile sub-element or an RNR element of a frame transmitted on the primary link. In some other implementations, the NSTR softAP MLD may also set a critical update flag (CUF) carried in the frame to a value of 1 based on the unavailability of a non-primary link. In some cases, the frame includes a capability information field with the CUF set to a value of 1.

[0167] FIG. 18 is a flow chart illustrating an example process 1800 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 1800 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 1800 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 1800 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0168] In some implementations, the process 1800 may be performed after transmitting a frame carrying an indication at block 1606 of FIG. 16. For example, at block 1802, the process 1800 begins with operating as a single-link device on the primary link based on the unavailability of the non-primary link. In some aspects, when the non-primary link is unavailable, the NSTR softAP MLD may place the softAP (or other transmit chain, receive chain, signal processing circuitry, etc.) associated with the non-primary link in a sleep, doze, or powered-off state while remaining fully operational on the primary link. In this single-link state, the NSTR softAP MLD may operate the BSS as a single-link BSS on the primary link while also reducing power consumption associated with operating on the non-primary link.

[0169] FIG. 19 is a flow chart illustrating an example process 1900 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. For example, the process 1900 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 1900 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 1900 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0170] In some implementations, the process 1900 may be performed while the NSTR softAP MLD operates as a single-link device at block 1802 of FIG. 18. For example, at block 1902, the process 1900 begins by determining that a non-primary link is available while operating as a single-link device on the primary link. At block 1904, the process 1900 continues by resetting a do not send (DNT) bit to a value of 0 based on the availability of the non-primary link. At block 1906, the process 1900 continues by transmitting a reset DNT bit in another frame only on the primary link, the other frame including a profile sub-element or a reduced neighbor report (RNR) element for each STA that has a reset DNT bit with a value of 0. In some cases, the other frame may be one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. In some other cases, the other frame may be an action frame, such as a notification frame.

[0171] FIG. 20 is a flow chart illustrating an example process 2000 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. For example, the process 2000 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2000 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2000 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0172] In some implementations, the process 2000 may be performed after the process 1600 of FIG. 16. For example, in block 2002, the process 2000 begins by determining that the non-primary link is available after sending an indication. In block 2004, the process 2000 continues by sending an indication of the availability of the non-primary link only on the primary link. In block 2006, the process 2000 continues by operating as a multi-link device on the primary link and the non-primary link based on the availability of the non-primary link. In some cases, the indication may be sent in a suitable management frame, such as, but not limited to, a beacon frame, a probe response frame, an association response frame, or a reassociation response frame, on the primary link. In some other cases, the indication may be sent in a suitable action frame, such as a notification frame, on the primary link. In some aspects, the NSTR softAP MLD may power on the softAP associated with the non-primary link when the non-primary link becomes available (or within a configured time). In this multi-link state, NSTR softAP MLD can operate the BSS on both the primary and non-primary links.

[0173] FIG. 21 is a flow chart illustrating an example process 2100 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 2100 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2100 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2100 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0174] In some implementations, the process 2100 may be performed after determining the unavailability of a non-primary link at block 1604 of FIG. 16. For example, at block 2102, the process 2100 begins with disabling the non-primary link or placing the non-primary link in a power saving state based on the unavailability of the non-primary link. In some instances, the NSTR softAP MLD may place the softAP (or other transmit chain, receive chain, signal processing circuitry, etc.) associated with the non-primary link in a sleep, doze, or powered off state while remaining fully operational on the primary link. In this manner, the NSTR softAP MLD may reduce power consumption associated with operating on the non-primary link and may also reduce cross-link interference resulting from UL transmissions on the non-primary link.

[0175] FIG. 22 is a flow chart illustrating an example process 2200 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. For example, the process 2200 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2200 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2200 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0176] In some implementations, the process 2200 may be one implementation of disabling a non-primary link at block 2102 of FIG. 21. For example, at block 2202, the process 2200 begins with removing the non-primary link from a multi-link context associated with the NSTR softAP MLD. In some instances, when the non-primary link is removed from the multi-link context, wireless communication devices associated with the NSTR softAP MLD may not be able to access or utilize the non-primary link. In some aspects, the NSTR softAP MLD may transmit a notification frame on the primary link to indicate that the non-primary link is no longer included in the multi-link context.

[0177] 23 is a flow chart illustrating an example process 2300 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 2300 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2300 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2300 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0178] In some implementations, the process 2300 may be performed after removing a non-primary link from a multilink context at block 2202 of FIG. 22. For example, at block 2302, the process 2300 begins with determining that the non-primary link is available after removing the non-primary link from the multilink context. At block 2304, the process 2300 continues with adding the non-primary link to the multilink context based on the determined availability of the non-primary link. In some instances, a wireless communication device associated with the NSTR softAP MLD may be able to access and utilize the non-primary link without disassociating or reassociating with the NSTR softAP MLD once the non-primary link is added to the multilink context. In some aspects, the NSTR softAP MLD may transmit a notification frame on the primary link to indicate that the non-primary link has been added to the multilink context.

[0179] FIG. 24 is a flow chart illustrating an example process 2400 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 2400 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2400 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2400 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0180] In some implementations, the process 2400 may be another implementation of disabling the non-primary link at block 2102 of FIG. 21. For example, at block 2402, the process 2400 begins with remapping a traffic identifier (TID) from the non-primary link to the primary link. As an example, the primary link may be initially associated or attributed with a first TID value indicating a first type or flow of traffic, and the non-primary link may be initially associated or attributed with a second TID value indicating a second type or flow of traffic. When the non-primary link is unavailable, the NSTR softAP MLD may remap the second TID value from the non-primary link to the primary link. In this manner, the traffic type or flow indicated by the second TID value may be communicated on the primary link (but not on the non-primary link). In some aspects, the NSTR softAP MLD may transmit a notification frame on the primary link to indicate that the TID belonging to the non-primary link has been remapped to the primary link.

[0181] FIG. 25 is a flow chart illustrating an example process 2500 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 2500 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2500 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2500 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0182] In some implementations, the process 2500 may be performed after remapping TIDs from a non-primary link to a primary link at block 2402 of FIG. 24. For example, at block 2502, the process 2500 begins with determining that a non-primary link is available after disabling the non-primary link. At block 2504, the process 2500 continues with remapping TIDs from the primary link to the non-primary link based on the availability of the non-primary link. Continuing with the example described with reference to FIG. 24, when the non-primary link becomes available, the NSTR softAP MLD may remap a second TID value from the primary link to the non-primary link. In this manner, communications of the traffic type or flow indicated by the second TID value may be returned to the non-primary link. In some aspects, the NSTR softAP MLD may transmit a notification frame on the primary link to indicate that some TIDs belonging to the primary link have been remapped to the non-primary link.

[0183] FIG. 26 is a flow chart illustrating an example process 2600 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 2600 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2600 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2600 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7B.

[0184] In some implementations, the process 2600 may be performed after transmitting a frame at block 1606 of Figure 16. For example, at block 2602, the process 2600 begins with switching a primary link from a first channel to a second channel simultaneously with switching a non-primary link from a second channel to a first channel. In some instances, the first channel is in one of the 5 GHz frequency band or the 6 GHz frequency band, and the second channel is in the other of the 5 GHz frequency band or the 6 GHz frequency band.

[0185] FIG. 27 is a flow chart illustrating an example process 2700 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 2700 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2700 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2700 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 8A.

[0186] In some implementations, process 2700 begins at block 2702 with receiving a clear to send (RTS) frame from the STA MLD on the primary link. At block 2704, process 2700 continues with transmitting a clear to send (CTS) frame to the STA MLD on the primary link and the non-primary link based on receiving the RTS frame. At block 2706, process 2700 continues with receiving one or more uplink (UL) physical layer protocol data units (PPDUs) from the STA MLD on the primary link and the non-primary link. In some instances, the NSTR softAP MLD may indicate availability of the non-primary link by transmitting a CTS frame on both the primary link and the non-primary link. When the STA MLD receives a CTS frame on both the primary link and the non-primary link, the STA MLD may transmit UL data on both the primary link and the non-primary link. Conversely, if the STA MLD receives a CTS frame only on the primary link, the STA MLD may transmit UL data to the NSTR softAP MLD only on the primary link.

[0187] FIG. 28 is a flow chart illustrating an example process 2800 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 2800 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2800 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2800 may be performed by a STA MLD, such as the STA MLD described with reference to FIG. 8B.

[0188] In some implementations, the process 2800 begins at block 2802 by receiving a first frame from an NSTR softAP MLD associated with the primary link and the non-primary links only on the primary link. The first frame may include a complete profile of the primary link and MLD information common to the primary link and the non-primary links. The complete profile may include at least a beacon interval, capability information, SSID, supported rates, a TSF value, and one or more additional fields or elements related to discovering the primary link. At block 2804, the process 2800 continues by transmitting a second frame to the NSTR softAP MLD only on the primary link, the second frame requesting a complete profile of the non-primary link. At block 2806, the process 2800 continues by receiving a third frame from the NSTR softAP MLD only on the primary link, the third frame indicating a complete profile of the non-primary link. In some instances, the first frame may be one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. The second frame may be one of a probe request frame, an association request frame, or a reassociation request frame. The third frame may be one of a probe response frame, an association response frame, or a reassociation response frame.

[0189] In some implementations, the first frame includes a frame body including a number of fields and elements carrying a complete profile of the primary link and including an ML element consisting of MLD common information. The third frame may include a frame body including an ML element carrying a profile sub-element for each STA indicating a complete profile of the non-primary link. The body of the third frame may also include an RNR element carrying a Neighbor AP Information field associated with the non-primary link. The Neighbor AP Information field may carry a TBTT Information field consisting of the BSSID and one or more MLD parameters of the non-primary link. In some instances, the TBTT offset, abbreviated SSID, BSS parameters, and PSD parameters of the non-primary link may be inherited from the primary link. Thus, the TBTT offset subfield, abbreviated SSID subfield, BSS parameters subfield, and PSD subfield may be omitted from the TBTT information field in the Neighbor AP Information field associated with the non-primary link, thereby reducing the size and overhead of the RNR element. In some aspects, the length of the TBTT information field is 9 octets.

[0190] FIG. 29 is a flow chart illustrating an example process 2900 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 2900 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 2900 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 2900 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 7A.

[0191] In some implementations, the process 2900 begins at block 2902 with operating as an NSTR softAP MLD associated with a primary link and a non-primary link. At block 2904, the process 2900 continues with transmitting a frame including one or more timing parameters associated with the primary link only on the primary link, where the timing parameters of the non-primary link are based on the one or more timing parameters associated with the primary link. In some aspects, the timing parameters of the non-primary link are inherited from the primary link. The frame may be one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame. In some instances, the primary link is associated with a target beacon transmission time (TBTT), and the non-primary link may be a pseudo BSS aligned with the TBTT of the primary link. The one or more timing parameters may include at least one of a channel switch announcement, a wait period, or a beacon interval.

[0192] FIG. 30 is a flow chart illustrating an example process 3000 for wireless communication with an NSTR softAP MLD according to some implementations. The process 3000 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 3000 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 3000 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 9A.

[0193] In some implementations, the process 3000 begins at block 3002 by operating as an NSTR softAP MLD associated with a primary link and a non-primary link. At block 3004, the process 3000 continues by obtaining channel access on the primary link. At block 3006, the process 3000 continues by transmitting a first frame to a first associated STA on the primary link. At block 3008, the process 3000 continues by putting the non-primary link into a diff state for the duration of the frame transmission on the primary link. At block 3010, the process 3000 continues by bringing the non-primary link out of the diff state after the end of the frame transmission on the primary link. In some implementations, the frame may be any suitable frame, including, but not limited to, a management frame, a control frame, or a data frame.

[0194] FIG. 31 is a flow chart illustrating an example process 3100 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 3100 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 3100 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 3100 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 9A.

[0195] In some implementations, the process 3100 may be performed after reinstating the non-primary link at block 3010 of FIG. 30. For example, at block 3102, the process 3100 begins with obtaining channel access on the non-primary link based on the channel access to the primary link. At block 3104, the process 3100 continues with transmitting a second frame on the non-primary link to a second associated STA simultaneously with transmitting a third frame on the primary link to a first associated STA. In some implementations, the NSTR softAP MLD may synchronize the transmission of the second frame on the non-primary link with the transmission of the third frame on the primary link. In some instances, the first associated STA is a legacy device configured to operate in accordance with IEEE 802.11ax or an earlier amendment to the 802.11 family of wireless communications standards, and the second associated STA is a non-legacy device configured to operate in accordance with IEEE 802.11be or a later amendment to the 802.11 family of wireless communications standards.

[0196] FIG. 32 is a flow chart illustrating an example process 3200 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. For example, the process 3200 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 3200 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 3200 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 9A.

[0197] In some implementations, the process 3200 may be performed after reinstating a non-primary link at block 3010 of FIG. 30. For example, at block 3202, the process 3200 begins with obtaining channel access on the non-primary link during at least a portion of the channel access obtained on the primary link. At block 3204, the process 3200 continues with transmitting a second frame to one or more second associated STAs on the non-primary link during transmission of the first frame on the primary link.

[0198] FIG. 33 is a flow chart illustrating an example process 3300 for wireless communication with an NSTR softAP MLD according to some implementations. The process 3300 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 3300 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 3300 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 9B.

[0199] In some implementations, the process 3300 begins at block 3302 by operating as an NSTR softAP MLD associated with a primary link and a non-primary link. At block 3304, the process 3300 continues with obtaining channel access to the primary link and the non-primary link. At block 3306, the process 3300 continues with establishing a coordinated target latency (TWT) session on the primary link and the non-primary link. At block 3308, the process 3300 continues with transmitting a first trigger frame on the primary link, the first trigger frame soliciting uplink (UL) transmissions from a first group of STAs on the primary link. At block 3310, the process 3300 continues with transmitting a second trigger frame on the non-primary link concurrently with the transmission of the first trigger frame on the primary link, the second trigger frame soliciting UL transmissions from a second group of STAs on the non-primary link. In some cases, a coordinated TWT session may include one or more respective service periods (SPs) during which a corresponding STA or a corresponding group of STAs may be scheduled or triggered for UL transmissions on respective primary and non-primary links.

[0200] FIG. 34 is a flow chart illustrating an example process 3400 for wireless communication with an NSTR softAP MLD according to some implementations. The process 3400 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 3400 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 3400 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 9B.

[0201] In some implementations, the process 3400 may be performed after transmitting a trigger frame at blocks 3308 and 3310 of FIG. 33. For example, the process 3400 may begin at block 3402 with receiving one or more first UL PPDUs from a first group of STAs over a primary link based on the first trigger frame. At block 3404, the process 3400 continues with receiving one or more second UL PPDUs from a second group of STAs over a non-primary link based on the second trigger frame. In some instances, the transmission of the first and second UL PPDUs from the first and second respective groups of STAs may be synchronized with one another.

[0202] FIG. 35 is a flow chart illustrating an example process 3500 for wireless communication with an NSTR softAP MLD according to some implementations. The process 3500 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 3500 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 3500 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 9B.

[0203] In some implementations, the process 3500 may be performed in conjunction with the process 3300 of Figure 33. For example, the process 3500 may begin at block 3502 with synchronizing one or more TWT service periods on a non-primary link with one or more respective TWT service periods on the primary link. In this manner, transmission of one or more first UL PPDUs by a first group of STAs on the primary link may be time-aligned with transmission of one or more second UL PPDUs by a second group of STAs on the non-primary link.

[0204] FIG. 36 is a flow chart illustrating an example process 3600 for wireless communication supporting multi-link communication with an NSTR softAP MLD, according to some implementations. The process 3600 may be performed by a wireless communication device, such as the wireless communication device 500 described above with reference to FIG. 5. In some implementations, the process 3600 may be performed by a wireless communication device operating as or within a STA, such as one of the STAs 104 or 604 described above with reference to FIG. 1 and FIG. 6B, respectively. In some instances, the process 3600 may be performed by an AP MLD, such as the NSTR softAP MLD described with reference to FIG. 9B.

[0205] In some implementations, process 3600 may be performed after receiving one or more first and second UL PPDUs at blocks 3402 and 3404 of FIG. 34. For example, process 3600 may begin with transmitting one or more first downlink (DL) PPDUs to a first group of STAs on a primary link at block 3602. At block 3604, process 3600 continues with transmitting one or more second DL PPDUs to a second group of STAs on a non-primary link concurrently with the transmission of the one or more first DL PPDUs to the first group of STAs on the primary link.

[0206] FIG. 37 illustrates a block diagram of an example wireless communication device 3700 according to some implementations. In some implementations, the wireless communication device 3700 is configured to perform the communication 700 of FIG. 7A, the communication 710 of FIG. 7B, or the communication 810 of FIG. 8A. The wireless communication device 3700 may be an example implementation of the wireless communication device 500 described above with reference to FIG. 5. For example, the wireless communication device 3700 may be a chip, SoC, chipset, package, or device including at least one processor and at least one modem (e.g., a Wi-Fi (IEEE 802.11) modem or a cellular modem). In some implementations, the wireless communication device 3700 may be a device for use in a STA, such as one of the STAs 104 and 604 described with reference to FIG. 1 and FIG. 6B, respectively. In some other implementations, the wireless communication device 3700 may be a STA including such a chip, SoC, chipset, package, or device, and at least one antenna (such as the antenna 625 of FIG. 6B). In various implementations, the wireless communication device 3700 may be an example of one or more of the NSTR softAP MLDs described herein.

[0207] The wireless communication device 3700 includes a receiving component 3710, a communications manager 3720, and a transmitting component 3730. The communications manager 3720 further includes a channel access component 3721, a frame generation component 3722, a link profile component 3723, a link availability component 3724, a parameter update component 3725, and a timing and synchronization component 3726. One or more portions of the components may be implemented at least partially in hardware or firmware. In some implementations, at least some of the components 3721, 3722, 3723, 3724, 3725, and 3726 are implemented at least partially as software stored in a memory (such as memory 508 of FIG. 5). For example, one or more portions of components 3721, 3722, 3723, 3724, 3725, and 3726 may be implemented as non-transitory instructions (or "code") executable by a processor (such as processor 506 in FIG. 5) to perform the functions or operations of the respective components.

[0208] The receiving component 3710 is configured to receive RX signals from other wireless communication devices over one or more wireless channels or links. The communications manager 3720 is configured to control or manage communications with other wireless communication devices. In some implementations, the channel access component 3721 contends for and obtains channel access to a primary link and / or a non-primary link associated with the wireless communication device 3700. The frame generation component 3722 generates frames for transmitting discovery information, profile information, operating parameters, updates to the operating parameters, link availability, link timing references, and other suitable information related to MLDs operating on the primary and non-primary links. The link profile component 3723 generates a complete or partial profile for one or more of the primary and non-primary links. The link availability component 3724 indicates whether the primary and / or non-primary links are available. The parameter update component 3725 determines changes to one or more parameters of the primary and non-primary links and transmits an indication of the parameter update. The timing and synchronization component 3726 generates a timing reference for the non-primary links relative to the primary link.

[0209] The transmitting component 3730 is configured to transmit TX signals over a wireless channel to one or more other wireless communication devices. In some implementations, the transmitting component 3730 may transmit frames including or indicating discovery information, profile information, operating parameters, updates to operating parameters, link availability, link timing references, and other suitable information regarding primary and non-primary links associated with the wireless communication device 3700.

[0210] FIG. 38 illustrates a block diagram of another exemplary wireless communication device 3800 according to some implementations. In some implementations, the wireless communication device 3800 is configured to perform the communication 810 of FIG. 8B. The wireless communication device 3800 may be an exemplary implementation of the wireless communication device 500 described above with reference to FIG. 5. For example, the wireless communication device 3800 may be a chip, SoC, chipset, package, or device including at least one processor and at least one modem (e.g., a Wi-Fi (IEEE 802.11) modem or a cellular modem). In some implementations, the wireless communication device 3800 may be a device for use in a STA, such as one of the STAs 104 and 604 described with reference to FIG. 1 and FIG. 6B, respectively. In some other implementations, the wireless communication device 3800 may be a STA including such a chip, SoC, chipset, package, or device and at least one antenna (such as the antenna 625 of FIG. 6B). In various implementations, the wireless communication device 3800 may be an example of any one or more of the STA MLDs described herein.

[0211] The wireless communication device 3800 includes a receiving component 3810, a communications manager 3820, and a transmitting component 3830. The communications manager 3820 further includes a channel access component 3821, a frame generation component 3822, and a profile request component 3823. One or more portions of the components may be implemented at least partially in hardware or firmware. In some implementations, at least some of the components 3821, 3822, and 3823 are implemented at least partially as software stored in a memory (such as memory 508). For example, one or more portions of the components 3821, 3822, and 3823 may be implemented as non-transitory instructions (or "code") executable by a processor (such as processor 506) to perform the functions or operations of the respective components.

[0212] The receiving component 3810 is configured to receive RX signals from other wireless communication devices over one or more wireless channels or links. The communications manager 3820 is configured to control or manage communications with other wireless communication devices. In some implementations, the channel access component 3821 contends for and obtains channel access to a primary link and / or a non-primary link associated with an AP MLD, such as an NSTR softAP MLD. The frame generating component 3822 generates frames to hold capabilities and operating parameters of the wireless communication device 3800. The profile request component 3823 generates a request for the AP MLD to provide a complete or partial profile of one or more of the primary and non-primary links.

[0213] The transmitting component 3830 is configured to transmit a TX signal over a wireless channel to one or more other wireless communication devices. In some implementations, the transmitting component 3830 may transmit frames that include or indicate capabilities, operational parameters, profile requests, and other suitable information for the primary and non-primary links associated with the AP MLD.

[0214] The following numbered sections explain implementation examples. 1. A method for wireless communication by a wireless station (STA), comprising: operating as a non-simultaneous transmit / receive (NSTR) soft AP multi-link device (MLD), including a first access point (AP) associated with a primary link and including a second AP associated with a non-primary link; 1. A method comprising: transmitting frames only on a primary link, the frames including a complete profile of the primary link and indicating a complete profile of a non-primary link, the complete profile of each of the primary link and non-primary links including at least a beacon interval, capability information, a service set identifier (SSID), supported rates, a timing synchronization function (TSF) value, and one or more additional fields or elements associated with discovery of the respective link.

[0215] 2. The method of claim 1, wherein the frame is one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame.

[0216] 3. A method according to any one or more of items 1 to 2, wherein the beacon interval, SSID, and TSF values ​​of the non-primary link are inherited from the primary link.

[0217] 4. The frame includes a frame body, the frame body being A number of fields and elements that hold the complete profile of the primary link; A method according to any one or more of items 1 to 3, comprising: a Multi-Link (ML) element having a profile sub-element for each STA indicating a complete profile of the non-primary link.

[0218] 5. The method of claim 4, wherein the ML element further includes a common information field carrying a BSS Parameter Change Count (BPCC) value indicating updates to one or more Basic Service Set (BSS) parameters associated with the primary link.

[0219] 6. The method according to any one or more of items 4 to 5, wherein one or more bits of the multilink control field or common information field of the ML element indicate whether the frame is being transmitted from the first AP of the NSTR softAP MLD.

[0220] 7. A method according to any one or more of items 4 to 6, wherein the frame body further includes a reduced neighbor report (RNR) element including a neighbor AP information field associated with a non-primary link, the neighbor AP information field including a target beacon transmission time (TBTT) information field consisting of a basic service set identity (BSSID) of the non-primary link and one or more MLD parameters.

[0221] 8. The method according to item 7, wherein the TBTT offset subfield, the shortened SSID subfield, the BSS parameters subfield, and the power spectral density (PSD) subfield are not present in the TBTT information field corresponding to the non-primary link.

[0222] 9. The method of any one or more of items 7-8, wherein the neighboring AP information field includes a TBTT information field type set to a value indicating that the neighboring AP information field holds information relating to only non-primary links.

[0223] 10. The method of claim 9, wherein the TBTT information field type is set to 1 or a reserved value.

[0224] 11. The method according to any one or more of items 7 to 10, wherein the length of the TBTT information field indicates whether the frame is transmitted from the first AP of the NSTR softAP MLD.

[0225] 12. The method according to any one or more of items 7 to 11, wherein the length of the TBTT information field is 9 octets.

[0226] 13. The method of any one or more of items 7 to 12, wherein the one or more MLD parameters carried in the TBTT information field include a BSS Parameter Change Count (BPCC) value indicating an update to one or more Basic Service Set (BSS) parameters associated with the non-primary link.

[0227] 14. Receiving an update to at least one of the BSS parameters associated with the non-primary link; and incrementing a value of a Basic Service Set (BSS) Parameter Change Count (BPCC) field in a Target Beacon Transmission Time (TBTT) information field included in a Reduced Neighbor Report (RNR) element of another frame based on the received update; setting a critical update flag (CUF) in a capability information field of the other frame based on incrementing the value of the BPCC field; Item 14. The method of item 13, further comprising: transmitting the other frame only on a primary link, the other frame indicating an update to at least one BSS parameter associated with a non-primary link.

[0228] 15. The method of claim 13, wherein the BSS parameters include at least one of a channel switch announcement (CSA) element, an extended channel switch announcement (eCSA) element, an enhanced distributed channel access (EDCA) parameter, a waiting period element, a direct sequence spread spectrum (DSSS) parameter set, a high throughput (HT) operation element, a very high throughput (VHT) operation element, a high efficiency (HE) operation element, an extremely high throughput (EHT) operation element, a wideband channel switch element, an operating mode notification element, a broadcast target latency (TWT) element, a BSS color change announcement element, a multi-user (MU) EDCA parameter set, a spatial reuse parameter set, or an uplink (UL) orthogonal frequency division multiple access (OFDMA) random access (UORA) parameter set.

[0229] 16. Receiving updates to one or more basic service set (BSS) parameters associated with the non-primary link; and 16. The method according to any one or more of items 1 to 15, further comprising: transmitting one or more updated BSS parameters associated with the non-primary links only on the primary link.

[0230] 17. The method of item 16, wherein the one or more updated BSS parameters are part of a partial profile of a non-primary link.

[0231] 18. A wireless communication device, comprising: At least one modem; at least one processor communicatively coupled to the at least one modem; and at least one memory communicatively coupled to the at least one processor and storing processor-readable code, the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, Operate as a non-simultaneous transmit / receive (NSTR) soft AP multi-link device (MLD), including a first access point (AP) associated with a primary link and including a second AP associated with a non-primary link; and 1. A wireless communications device configured to transmit frames only on a primary link, the frames including a complete profile of the primary link and indicating a complete profile of a non-primary link, the respective complete profiles of the primary link and non-primary links each including at least a beacon interval, capability information, a service set identifier (SSID), supported rates, a timing synchronization function (TSF) value, and one or more additional fields or elements associated with discovery of the respective link.

[0232] 19. The wireless communication device of item 18, wherein the frame is one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame.

[0233] 20. A wireless communication device according to any one or more of items 18-19, wherein the beacon interval, SSID, and TSF values ​​of the non-primary link are inherited from the primary link.

[0234] 21. The frame includes a frame body, the frame body being A number of fields and elements that hold the complete profile of the primary link; A multilink (ML) element having a profile sub-element for each STA indicating a complete profile of a non-primary link.

[0235] 22. The wireless communication device of item 21, wherein the ML element further includes a common information field carrying a BSS Parameter Change Count (BPCC) value indicating updates to one or more Basic Service Set (BSS) parameters associated with the primary link.

[0236] 23. A wireless communication device described in any one or more of items 21 to 22, wherein one or more bits of a multilink control field or a common information field of an ML element indicate whether the frame is being transmitted from a first AP of an NSTR softAP MLD.

[0237] 24. A wireless communication device according to any one or more of items 21 to 23, wherein the frame body further includes a reduced neighbor report (RNR) element including a neighbor AP information field associated with a non-primary link, the neighbor AP information field including a target beacon transmission time (TBTT) information field consisting of a basic service set identity (BSSID) of the non-primary link and one or more MLD parameters.

[0238] 25. The wireless communication device of item 24, wherein the TBTT offset subfield, the shortened SSID subfield, the BSS parameters subfield, and the power spectral density (PSD) subfield are not present in the TBTT information field corresponding to the non-primary link.

[0239] 26. A wireless communications device as described in any one or more of clauses 24 to 25, wherein the neighboring AP information field includes a TBTT information field type set to a reserved value indicating that the neighboring AP information field contains information relating only to non-primary links.

[0240] 27. A wireless communication device according to any one or more of items 24 to 26, wherein the length of the TBTT information field indicates whether the frame is being transmitted from the first AP of the NSTR softAP MLD.

[0241] 28. The wireless communication device of item 24, wherein the one or more MLD parameters retained in the TBTT information field include a BSS Parameter Change Count (BPCC) value indicating an update to one or more Basic Service Set (BSS) parameters associated with the non-primary link.

[0242] 29. Execution of processor-readable code receiving an update to at least one of the BSS parameters associated with the non-primary link; incrementing a value of a Basic Service Set (BSS) Parameter Change Count (BPCC) field in a Target Beacon Transmission Time (TBTT) information field included in a Reduced Neighbor Report (RNR) element of another frame based on the received update; setting a critical update flag (CUF) in a capability information field of the other frame based on incrementing the value of the BPCC field; 30. The wireless communication device of claim 28, further configured to: transmit the other frame only on a primary link, the other frame indicating an update to at least one BSS parameter associated with a non-primary link.

[0243] 30. Execution of processor-readable code receiving updates to one or more basic service set (BSS) parameters associated with the non-primary link; 30. The wireless communication device of any one or more of items 18-29, further configured to: transmit one or more updated BSS parameters associated with the non-primary links only on the primary link.

[0244] 31. A method for wireless communication by a wireless station (STA), comprising: operating as a non-simultaneous transmit / receive (NSTR) soft AP multi-link device (MLD), including a first access point (AP) associated with a primary link and including a second AP associated with a non-primary link; determining that a non-primary link is unavailable; transmitting a frame carrying an indication of unavailability of the non-primary link only on the primary link.

[0245] 32. The method of claim 31, wherein the frame includes one of a beacon frame, a probe response frame, an association response frame, a reassociation response frame, or an action frame.

[0246] 33. A method according to any one or more of items 31 to 32, wherein the frame includes a profile sub-element or a reduced neighbor report (RNR) element for each STA having a do not send (DNT) bit set to a value of 1, the DNT bit being set to a value of 1 indicating unavailability of a non-primary link.

[0247] 34. The method according to any one or more of items 31 to 33, wherein the frame includes a capability information field carrying a critical update flag (CUF), the CUF being set to a value of 1 based on unavailability of a non-primary link.

[0248] 35. The method of any one or more of items 31-34, further comprising operating as a single-link device on the primary link based on unavailability of a non-primary link.

[0249] 36. Determining that a non-primary link is available while operating as a single-link device on a primary link; resetting a do not send (DNT) bit to a value of 0 based on the availability of a non-primary link; Item 36. The method of item 35, further comprising: transmitting a reset DNT bit of another frame only on the primary link, the another frame including a profile sub-element or a reduced neighbor report (RNR) element for each STA that has a reset DNT bit with a value of 0.

[0250] 37. After transmitting the instruction, determining that the non-primary link is available; and transmitting an indication of availability of the non-primary links only on the primary link; 37. The method of any one or more of items 31-36, further comprising operating as a multi-link device on the primary link and the non-primary links based on availability of the non-primary links.

[0251] 38. The method of any one or more of items 31-36, further comprising disabling the non-primary links or placing the non-primary links in a power saving state based on unavailability of the non-primary links.

[0252] 39. The method of claim 38, wherein disabling the non-primary link includes removing the non-primary link from a multi-link context associated with the NSTR softAP MLD.

[0253] 40. Determining that the non-primary link is available after removing the non-primary link from the multilink context; 40. The method of claim 39, further comprising adding non-primary links to the multilink context based on availability of the non-primary links.

[0254] 41. The method of claim 38, wherein disabling the non-primary link includes remapping a traffic identifier (TID) from the non-primary link to the primary link.

[0255] 42. Determining that the non-primary links are available after disabling the non-primary links; Item 42. The method of item 41, further comprising remapping the TID from the primary link to the non-primary link based on availability of the non-primary link.

[0256] 43. Receiving a ready to send (RTS) frame from a STA MLD on a primary link; transmitting a clear to send (CTS) frame to the STA MLD on the primary link and the non-primary link based on receiving the RTS frame; 43. The method according to any one or more of items 31 to 42, further comprising receiving one or more uplink (UL) physical layer protocol data units (PPDUs) from the STA MLD on the primary link and the non-primary link.

[0257] 44. The method of any one or more of items 31-42, further comprising switching the primary link from the first channel to the second channel simultaneously with switching the non-primary link from the second channel to the first channel.

[0258] 45. The method of claim 44, wherein the first channel is in one of the 5 GHz frequency band or the 6 GHz frequency band, and the second channel is in the other of the 5 GHz frequency band or the 6 GHz frequency band.

[0259] 46. ​​A wireless communication device, comprising: At least one modem; at least one processor communicatively coupled to the at least one modem; and at least one memory communicatively coupled to the at least one processor and storing processor-readable code, the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, Operate as a non-simultaneous transmit / receive (NSTR) soft AP multi-link device (MLD), including a first access point (AP) associated with a primary link and including a second AP associated with a non-primary link; Determining that a non-primary link is unavailable, and 11. A wireless communications device configured to transmit a frame bearing an indication of unavailability of a non-primary link only on a primary link.

[0260] 47. The wireless communication device of item 46, wherein the frame includes one of a beacon frame, a probe response frame, an association response frame, a reassociation response frame, or an action frame.

[0261] 48. A wireless communications device according to any one or more of items 46 to 47, wherein the frame includes a profile sub-element or a reduced neighbor report (RNR) element for each STA having a do not transmit (DNT) bit set to a value of 1, the DNT bit set to a value of 1 indicating unavailability of a non-primary link.

[0262] 49. A wireless communications device according to any one or more of items 46-47, wherein the frame includes a capability information field carrying a Critical Update Flag (CUF), the CUF being set to a value of 1 based on unavailability of a non-primary link.

[0263] 50. Execution of processor-readable code 50. The wireless communication device of any one or more of items 46-49, further configured to operate as a single link device on the primary link based on unavailability of a non-primary link.

[0264] 51. Execution of processor-readable code determining that a non-primary link is available while operating as a single-link device on the primary link; resetting the Do Not Send (DNT) bit to a value of 0 based on the availability of a non-primary link, and Item 51. The wireless communication device of item 50, further configured to transmit a reset DNT bit of another frame only on the primary link, the another frame including a profile sub-element or a reduced neighbor report (RNR) element for each STA that has a reset DNT bit with a value of 0.

[0265] 52. Execution of processor-readable code determining that the non-primary link is available after sending the indication; transmits indications of non-primary link availability only on the primary link, and 52. The wireless communication device of any one or more of items 46-51, further configured to operate as a multi-link device on the primary link and the non-primary links based on the availability of the non-primary links.

[0266] 53. A wireless communication device according to any one or more of clauses 46 to 52, wherein execution of the processor-readable code is further configured to disable the non-primary link or place the non-primary link in a power saving state based on unavailability of the non-primary link.

[0267] 54. The wireless communications device of item 53, wherein disabling the non-primary link includes removing the non-primary link from a multilink context associated with the NSTR softAP MLD.

[0268] 55. Execution of processor-readable code determining that the non-primary link is available after removing the non-primary link from the multilink context; and Item 55. The wireless communication device of item 54, further configured to add non-primary links to the multilink context based on availability of the non-primary links.

[0269] 56. The wireless communications device of item 53, wherein disabling the non-primary link includes remapping a traffic identifier (TID) from the non-primary link to the primary link.

[0270] 57. Execution of processor-readable code determining that the non-primary links are available after disabling the non-primary links; and Item 57. The wireless communication device of item 56, further configured to remap the TID from the primary link to the non-primary link based on availability of the non-primary link.

[0271] 58. Execution of processor-readable code Receives a Ready to Send (RTS) frame from the STA MLD on the primary link Transmitting a Clear to Send (CTS) frame to the STA MLD on the primary link and on the non-primary link based on receiving the RTS frame; and 58. The wireless communication device of any one or more of items 46 to 57, further configured to receive one or more uplink (UL) physical layer protocol data units (PPDUs) from the STA MLD on the primary link and the non-primary link.

[0272] 59. Execution of processor-readable code 59. The wireless communication device of any one or more of items 46-58, further configured to switch the primary link from the first channel to the second channel simultaneously with switching the non-primary link from the second channel to the first channel.

[0273] 60. The wireless communication device of item 59, wherein the first channel is in one of the 5 GHz frequency band or the 6 GHz frequency band, and the second channel is in the other of the 5 GHz frequency band or the 6 GHz frequency band.

[0274] 61. A method for wireless communication by a wireless station (STA), comprising: receiving, on only the primary link, a first frame from a non-simultaneous transmit / receive (NSTR) soft access point (AP) multi-link device (MLD) associated with the primary link and the non-primary links, the first frame including a complete profile of the primary link and MLD information common to the primary link and the non-primary links, the complete profile including at least a beacon interval, capability information, a service set identifier (SSID), supported rates, a timing synchronization function (TSF) value, and one or more additional fields or elements associated with discovering the primary link; sending a second frame to the NSTR softAP MLD only on the primary link, the second frame requesting a complete profile for the non-primary link; receiving a third frame from the NSTR softAP MLD only on the primary link, the third frame indicating a complete profile of the non-primary link.

[0275] 62. The method of item 61, wherein the first frame is a beacon frame, the second frame is a probe request frame, and the third frame is a probe response frame.

[0276] 63. A method according to any one or more of items 61 to 62, wherein the first frame includes a frame body carrying a complete profile of the primary link and including a multi-link (ML) element consisting of MLD common information.

[0277] 64. The method of item 63, wherein the MLD common information includes an MLD medium access control (MAC) address field, a link ID information field, a basic service set (BSS) parameter change count (BPCC) field, a synchronization delay field, an enhanced multilink (EML) capability field, and an MLD capability field.

[0278] 65. The method of item 64, wherein the BPCC field indicates an update to one or more BSS parameters associated with the primary link.

[0279] 66. A method according to any one or more of items 64 to 65, in which link information of a non-primary link is not present in the ML element of the first frame.

[0280] 67. The method of any one or more of items 61 to 66, wherein the third frame includes a frame body including a multi-link (ML) element carrying profile sub-elements for each STA indicating a complete profile of the non-primary link.

[0281] 68. The method of item 67, wherein the frame body of the third frame further includes a reduced neighbor report (RNR) element carrying a neighbor AP information field associated with the non-primary link, the neighbor AP information field carrying a target beacon transmission time (TBTT) information field consisting of a basic service set identity (BSSID) and one or more MLD parameters of the non-primary link.

[0282] 69. The method according to item 68, wherein the TBTT offset subfield, the shortened SSID subfield, the BSS parameters subfield, and the power spectral density (PSD) subfield are not present in the TBTT information field corresponding to the non-primary link.

[0283] 70. The method according to any one or more of items 61 to 69, wherein the beacon interval, SSID, and TSF values ​​of the non-primary link are inherited from the primary link.

[0284] 71. A wireless communication device, comprising: At least one modem; at least one processor communicatively coupled to the at least one modem; and at least one memory communicatively coupled to the at least one processor and storing processor-readable code, the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, receiving, on only the primary link, a first frame from a non-simultaneous transmit / receive (NSTR) soft access point (AP) multi-link device (MLD) associated with the primary link and the non-primary links, the first frame including a complete profile of the primary link and MLD information common to the primary link and the non-primary links, the complete profile including at least a beacon interval, capability information, a service set identifier (SSID), supported rates, a timing synchronization function (TSF) value, and one or more additional fields or elements associated with discovering the primary link; sending a second frame to the NSTR softAP MLD only on the primary link, the second frame requesting a complete profile for the non-primary link; and receiving a third frame from an NSTR softAP MLD only on a primary link, the third frame indicating a complete profile of a non-primary link.

[0285] 72. The wireless communication device of item 71, wherein the first frame is a beacon frame, the second frame is a probe request frame, and the third frame is a probe response frame.

[0286] 73. A wireless communication device according to any one or more of items 71 to 72, wherein the first frame includes a frame body carrying a complete profile of the primary link and including a multi-link (ML) element consisting of MLD common information.

[0287] 74. The wireless communication device of item 73, wherein the MLD common information includes an MLD medium access control (MAC) address field, a link ID information field, a basic service set (BSS) parameter change count (BPCC) field, a synchronization delay field, an enhanced multilink (EML) capability field, and an MLD capability field.

[0288] 75. The wireless communications device of item 74, wherein the BPCC field indicates an update to one or more BSS parameters associated with the primary link.

[0289] 76. The wireless communication device of item 73, wherein link information for a non-primary link is not present in the ML element of the first frame.

[0290] 77. A wireless communications device according to any one or more of items 71 to 76, wherein the third frame includes a frame body including a multi-link (ML) element carrying a profile sub-element for each STA indicating a complete profile of the non-primary link.

[0291] 78. The wireless communication device of item 77, wherein the frame body of the third frame further includes a reduced neighbor report (RNR) element carrying a neighbor AP information field associated with the non-primary link, the neighbor AP information field carrying a target beacon transmission time (TBTT) information field consisting of a basic service set identity (BSSID) and one or more MLD parameters of the non-primary link.

[0292] 79. The wireless communication device of item 78, wherein the TBTT offset subfield, the shortened SSID subfield, the BSS parameters subfield, and the power spectral density (PSD) subfield are not present in the TBTT information field corresponding to the non-primary link.

[0293] 80. A wireless communication device according to any one or more of items 71 to 79, wherein the beacon interval, SSID, and TSF values ​​of the non-primary link are inherited from the primary link.

[0294] 81. A method for wireless communication by a wireless station (STA), comprising: Operate as a non-simultaneous transmit / receive (NSTR) soft access point (AP) multi-link device (MLD) associated with a primary link and a non-primary link; transmitting a frame only on the primary link that includes one or more timing parameters associated with the primary link, wherein the non-primary links include one or more timing parameters inherited from the primary link.

[0295] 82. The method of claim 81, wherein the frame is one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame.

[0296] 83. The method of any one or more of clauses 81-82, wherein the one or more timing parameters include at least one of a channel switch announcement, a wait period, or a beacon interval.

[0297] 84. The method of any one or more of items 81-83, wherein the primary link is associated with a target beacon transmission time (TBTT) and the non-primary links include a pseudo BSS aligned with the TBTT of the primary link.

[0298] 85. The method of any one or more of items 81-84, wherein a target latency (TWT) session established on a non-primary link is synchronized with a TWT session established on the primary link.

[0299] 86. The method of any one or more of items 81-85, further comprising aligning uplink (UL) transmissions to the NSTR softAP MLD on the non-primary link with UL transmissions to the NSTR softAP MLD on the primary link.

[0300] 87. A wireless communication device, comprising: At least one modem; at least one processor communicatively coupled to the at least one modem; and at least one memory communicatively coupled to the at least one processor and storing processor-readable code, the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, Operates as a non-simultaneous transmit / receive (NSTR) soft access point (AP) multilink device (MLD) associated with a primary link and a non-primary link, and 1. A wireless communications device configured to transmit frames including one or more timing parameters associated with the primary link only on a primary link, wherein non-primary links include one or more timing parameters inherited from the primary link.

[0301] 88. The wireless communication device of item 87, wherein the frame is one of a beacon frame, a probe response frame, an association response frame, or a reassociation response frame.

[0302] 89. The wireless communication device of any one or more of clauses 87-88, wherein the one or more timing parameters include at least one of a channel switch announcement, a wait period, or a beacon interval.

[0303] 90. A wireless communication device according to any one or more of items 87-89, wherein the primary link is associated with a target beacon transmission time (TBTT) and the non-primary links include a pseudo BSS aligned with the TBTT of the primary link.

[0304] 91. A wireless communications device according to any one or more of items 87-90, wherein a target latency (TWT) session established on a non-primary link is synchronized with a TWT session established on the primary link.

[0305] 92. Execution of processor-readable code 92. The wireless communication device of any one or more of items 87-91, further configured to align uplink (UL) transmissions to the NSTR softAP MLD on a non-primary link with UL transmissions to the NSTR softAP MLD on a primary link.

[0306] 93. A method for wireless communication by a wireless station (STA), comprising: Operate as a non-simultaneous transmit / receive (NSTR) soft access point (AP) multi-link device (MLD) associated with a primary link and a non-primary link; Obtaining channel access on a primary link; transmitting a first frame on a primary link to a first associated STA; placing the non-primary links in a def state for the duration of the frame transmission on the primary link; and returning the non-primary links from a diff state after completion of frame transmission on the primary link.

[0307] 94. The method of claim 93, wherein the first frame comprises a management frame, a control frame, or a data frame.

[0308] 95. Obtaining channel access on a non-primary link based on channel access obtained on a primary link; 96. The method of any one or more of items 93-95, further comprising transmitting the second frame to the second associated STA on the non-primary link simultaneously with transmitting the third frame to the first associated STA on the primary link.

[0309] 96. The method of item 95, wherein the first associated STA is a legacy device configured to operate in accordance with IEEE 802.11ax or an earlier amendment to the 802.11 family of wireless communications standards, and the second associated STA is a non-legacy device configured to operate in accordance with IEEE 802.11be or a later amendment to the 802.11 family of wireless communications standards.

[0310] 97. The method of claim 95, further comprising synchronizing transmission of the second frame on the non-primary link with transmission of the third frame on the primary link.

[0311] 98. Obtaining channel access on a non-primary link during at least a portion of the channel access obtained on the primary link; Item 94. The method of item 93, further comprising: transmitting a second frame on a non-primary link to one or more second associated STAs during transmission of the first frame on the primary link.

[0312] 99. The method of item 98, wherein the first frame is a beacon frame and the second frame is an aggregated transmission to one or more second associated STAs.

[0313] 100. The method of claim 99, wherein the one or more second associated STAs are multi-radio devices operating on the primary link and the non-primary link.

[0314] 101. A wireless communication device, comprising: At least one modem; at least one processor communicatively coupled to the at least one modem; and at least one memory communicatively coupled to the at least one processor and storing processor-readable code, the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, Acts as a non-simultaneous transmit / receive (NSTR) soft access point (AP) multilink device (MLD) associated with a primary link and a non-primary link; Obtain channel access on the primary link, Transmitting a first frame on a primary link to a first associated STA; Putting the non-primary links into a DEF state for the duration of the frame transmission on the primary link, and 11. A wireless communications device configured to restore a non-primary link from a def state after completion of frame transmission on the primary link.

[0315] 102. The wireless communication device of item 101, wherein the first frame comprises a management frame, a control frame, or a data frame.

[0316] 103. Execution of processor-readable code Obtaining channel access on the non-primary link based on the channel access obtained on the primary link; and 103. The wireless communication device of claim 101, further configured to transmit a second frame to a second associated STA on a non-primary link simultaneously with transmitting a third frame to a first associated STA on the primary link.

[0317] 104. The wireless communication device of item 103, wherein the first associated STA is a legacy device configured to operate in accordance with IEEE 802.11ax or an earlier amendment to the 802.11 family of wireless communications standards, and the second associated STA is a non-legacy device configured to operate in accordance with IEEE 802.11be or a later amendment to the 802.11 family of wireless communications standards.

[0318] 105. Execution of processor-readable code Item 104. The wireless communication device of item 103, further configured to synchronize transmission of the second frame on the non-primary link with transmission of the third frame on the primary link.

[0319] 106. Execution of processor-readable code obtaining channel access on a non-primary link during at least a portion of the channel access obtained on the primary link; and Item 102. The wireless communication device of item 101, further configured to transmit a second frame on a non-primary link to one or more second associated STAs during transmission of the first frame on the primary link.

[0320] 107. The wireless communications device of item 106, wherein the first frame is a beacon frame and the second frame is an aggregated transmission to one or more second associated STAs.

[0321] 108. The wireless communications device of item 107, wherein the one or more second associated STAs are multi-radio devices operating on a primary link and a non-primary link.

[0322] 109. A method for wireless communication by a wireless station (STA), comprising: Operate as a non-simultaneous transmit / receive (NSTR) soft access point (AP) multi-link device (MLD) associated with a primary link and a non-primary link; Obtaining channel access to a primary link and a non-primary link; establishing a coordinated target latency (TWT) session on a primary link and a non-primary link; transmitting a first trigger frame on a primary link, the first trigger frame soliciting uplink (UL) transmissions from a first group of STAs on the primary link; transmitting a second trigger frame on a non-primary link concurrently with transmitting a first trigger frame on the primary link, the second trigger frame requesting UL transmissions from a second group of STAs on the non-primary link.

[0323] 110. Receiving one or more first UL physical layer protocol data units (PPDUs) from a first group of STAs on a primary link based on a first trigger frame; Item 109. The method of item 109, further comprising: receiving one or more second UL PPDUs from a second group of STAs on the non-primary link based on the second trigger frame.

[0324] 111. The method of claim 110, further comprising synchronizing one or more TWT service periods on the non-primary links with one or more respective TWT service periods on the primary link.

[0325] 112. The method of item 110, wherein transmission of one or more second UL PPDUs by a second group of STAs on the primary link is time-aligned with transmission of one or more first UL PPDUs by a first group of STAs on the primary link.

[0326] 113. Transmitting one or more first downlink (DL) PPDUs to a first group of STAs on a primary link; Item 111. The method of item 110, further comprising: transmitting one or more second DL PPDUs to a second group of STAs on a non-primary link simultaneously with transmitting one or more first DL PPDUs to a first group of STAs on the primary link.

[0327] 114. A wireless communication device, comprising: At least one modem; at least one processor communicatively coupled to the at least one modem; and at least one memory communicatively coupled to the at least one processor and storing processor-readable code, the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, Acts as a non-simultaneous transmit / receive (NSTR) soft access point (AP) multilink device (MLD) associated with a primary link and a non-primary link; Obtaining channel access to the primary and non-primary links; Establishing a coordinated target latency (TWT) session on the primary link and on the non-primary links; transmitting a first trigger frame on a primary link, the first trigger frame requesting uplink (UL) transmissions from a first group of STAs on the primary link; and 1. A wireless communications device configured to transmit a second trigger frame on a non-primary link concurrently with transmission of a first trigger frame on a primary link, the second trigger frame soliciting UL transmissions from a second group of STAs on the non-primary link.

[0328] 115. Execution of processor-readable code receiving one or more first UL physical layer protocol data units (PPDUs) on a primary link from a first group of STAs based on a first trigger frame; and Item 115. The wireless communication device of item 114, further configured to receive one or more second UL PPDUs on the non-primary link from a second group of STAs based on the second trigger frame.

[0329] 116. Execution of processor-readable code Item 116. The wireless communication device of item 115, further configured to synchronize one or more TWT service periods on the non-primary links with one or more respective TWT service periods on the primary link.

[0330] 117. The wireless communications device of item 115, wherein transmission of one or more second UL PPDUs by a second group of STAs on the primary link is time-aligned with transmission of one or more first UL PPDUs by a first group of STAs on the primary link.

[0331] 118. Execution of processor-readable code Transmitting one or more first downlink (DL) PPDUs to a first group of STAs on a primary link; and Item 116. The wireless communications device of item 115, further configured to transmit one or more second DL PPDUs to a second group of STAs on a non-primary link simultaneously with transmitting one or more first DL PPDUs to a first group of STAs on the primary link.

[0332] As used herein, a phrase referring to "at least one of" or "one or more of" a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to encompass the possibilities of a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a, b, and c.

[0333] The various example components, logic, logic blocks, modules, circuits, operations, and algorithmic processes described with respect to implementations disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware, or software, including the structures disclosed herein and structural equivalents thereof. The interchangeability of hardware, firmware, and software has been described generally in terms of functionality and illustrated in the various example components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware, firmware, or software depends on the particular application and design constraints imposed on the overall system.

[0334] Various modifications of the implementations described in this disclosure may be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the spirit or scope of the present disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but are to be accorded the widest scope consistent with the present disclosure, the principles and novel features disclosed herein.

[0335] Moreover, various features described herein in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations separately or in any suitable subcombination. Thus, although features may be described above as working in a particular combination and may even initially be claimed as such, in some cases one or more features from a claimed combination may be deleted from that combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0336] Similarly, although operations are shown in the figures in a particular order, this should not be understood as requiring such operations to be performed in the particular order or sequential order shown, or that all of the operations shown be performed, to achieve a desired result. Furthermore, the figures may generally illustrate one or more exemplary processes in the form of a flow chart or flow diagram. However, other operations not shown may be incorporated into the generally illustrated exemplary process. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. In some situations, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the program components and systems described may generally be integrated together in a single software product or packaged into multiple software products.

Claims

1. A method for wireless communication by a wireless station (STA), comprising: operating as a non-simultaneous transmit and receive (NSTR) soft AP multi-link device (MLD) that includes a first access point (AP) associated with a primary link and a second AP associated with a non-primary link; determining that the non-primary link is unavailable; transmitting, only on the primary link, a frame carrying an indication of the unavailability of the non-primary link; based on the unavailability of the non-primary link, disabling the non-primary link or putting the non-primary link into a power-saving state.

2. The method according to claim 1, wherein the frame includes one of a beacon frame, a probe response frame, an association response frame, a re-association response frame, or an action frame.

3. The method according to claim 1, wherein the frame includes a profile sub-element or a reduced neighbor report (RNR) element for each STA that carries a transmit disable (DNT) bit set to a value of 1, and the DNT bit set to the value of 1 indicates the unavailability of the non-primary link.

4. The method according to claim 1, wherein the frame includes a capability information field that carries a critical update flag (CUF), and the CUF is set to a value of 1 based on the unavailability of the non-primary link.

5. The method according to claim 1, further comprising operating as a single-link device on the primary link based on the unavailability of the non-primary link.

6. Determining that the non-primary link is available while operating as the single link device on the primary link; Resetting a Do Not Transmit (DNT) bit to a value of 0 based on the availability of the non-primary link; Further comprising transmitting a reset DNT bit for another frame only on the primary link, wherein the another frame includes a profile sub-element or a reduced neighbor report (RNR) element for each STA having the reset DNT bit having the value of 0, the method of claim 5. **Claim 7** After transmitting the indication, determining that the non-primary link is available; Transmitting an indication of the availability of the non-primary link only on the primary link; Further comprising operating as a multi-link device on the primary link and the non-primary link based on the availability of the non-primary link, the method of claim 1. **Claim 8** Invalidating the non-primary link includes removing the non-primary link from a multi-link context associated with the NSTR softAP MLD, the method of claim 1. **Claim 9** After removing the non-primary link from the multi-link context, determining that the non-primary link is available; Further comprising adding the non-primary link to the multi-link context based on the availability of the non-primary link, the method of claim 8. **Claim 10** Invalidating the non-primary link includes remapping a traffic identifier (TID) from the non-primary link to the primary link, the method of claim 1. **Claim 11** After invalidating the non-primary link, determining that the non-primary link is available; Remapping the TID from the primary link to the non-primary link based on the availability of the non-primary link, the method according to claim 10, further comprising. **Claim 12** Receiving a transmission ready (RTS) frame from the STA MLD on the primary link; Based on receiving the RTS frame, transmitting a clear to send (CTS) frame to the STA MLD on the primary link and the non-primary link; Receiving one or more uplink (UL) physical layer protocol data units (PPDUs) from the STA MLD on the primary link and the non-primary link, the method according to claim 1, further comprising. **Claim 13** Switching the non-primary link from a second channel to a first channel and simultaneously switching the primary link from the first channel to the second channel, the method according to claim 1, further comprising. **Claim 14** The method according to claim 13, wherein the first channel is in one of a 5 GHz frequency band or a 6 GHz frequency band, and the second channel is in the other of the 5 GHz frequency band or the 6 GHz frequency band. **Claim 15** A wireless communication device, At least one modem; At least one processor communicatively coupled to the at least one modem; At least one memory communicatively coupled to the at least one processor and storing processor-readable code, which when executed by the at least one processor in cooperation with the at least one modem, causes the wireless communication device to configured to operate as a non-simultaneous transmit and receive (NSTR) soft access point multi-link device (MLD) that includes a first access point (AP) associated with a primary link and a second AP associated with a non-primary link, determine that the non-primary link is unavailable, and a wireless communication device configured to transmit a frame carrying an indication of the unavailability of the non-primary link only on the primary link.

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