Multi-link traffic indication for multi-link devices

Abstract

A wireless communication network includes an access point (AP) multilink device (MLD) and a non-AP MLD. The AP MLD generates a traffic indication graph (TIM) element that indicates suspended buffered traffic for a plurality of non-AP MLDs associated with the AP MLD, and based on determining whether all of the plurality of non-AP MLDs have a default traffic identifier (TID)-to-link mapping and whether the AP MLD has buffered traffic with TIDs of all enabled links that are not mapped to at least one non-AP MLD. A multi-link traffic indication element is selectively generated that includes a per-link traffic indication for retrieving buffered traffic for at least one non-AP MLD. The AP MLD sends a beacon frame including a TIM element and an optional multi-link traffic indication element to a plurality of non-AP MLDs.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communications, and more particularly to multilink traffic indication, for example but not limited to, for multilink devices in wireless communication systems. Background Art

[0002] Since the late 1990s, wireless local area network (WLAN) technology has evolved toward increased data rates and continues its growth in various markets such as home, enterprise, and hotspots. WLAN allows devices to access the Internet in the 2.4GHz, 5GHz, 6GHz, or 60GHz frequency bands. WLAN is based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. The IEEE802.11 family of standards is designed to increase speed and reliability and extend the operating range of wireless networks.

[0003] WLAN devices are increasingly required to support various delay-sensitive or real-time applications, such as augmented reality (AR), robotics, artificial intelligence (AI), cloud computing, and driverless vehicles. In order to achieve the extremely low latency and extremely high throughput required for such applications, multi-link operation (MLO) has been proposed for WLAN. A WLAN is formed by WLAN devices in a limited area such as a home, school, apartment, or office building. Each WLAN device may have one or more stations (STAs), such as an access point (AP) STA and a non-access point (non-AP) STA.

[0004] MLO can enable a non-AP multi-link device (MLD) to establish multiple links with an AP MLD. Each of the multiple links can independently implement channel access and frame exchange between the non-AP MLD and the AP MLD, which can reduce latency and increase throughput.

[0005] The descriptions set forth in the Background section should not be assumed to be prior art merely because they are set forth in the Background section. The Background section may describe aspects or embodiments of the present disclosure. Summary of the invention

[0006] One embodiment of the present disclosure provides an access point (AP) multi-link device (MLD) associated with a wireless network. The AP MLD includes at least two APs attached to the AP MLD and a processor coupled to the at least two APs. The processor is configured to generate a traffic indication map (TIM) element, the TIM element indicating pending buffered traffic of multiple non-AP MLDs associated with the AP MLD. The processor is configured to selectively generate a multi-link traffic indication element based on determining whether all multiple non-AP MLDs have a default traffic identifier (TID) to link mapping and whether the AP MLD has buffered traffic with a TID mapped to all enabled links of at least one non-AP MLD, the multi-link traffic indication element including a per-link traffic indication for retrieving buffered traffic for at least one non-AP MLD. The processor is configured to generate a beacon frame including the TIM element and the selectively included multi-link traffic indication element. The processor is configured to send the beacon frame to multiple non-AP MLDs.

[0007] In some embodiments, the processor is configured to generate a multi-link traffic indication element when at least one of the associated non-AP MLDs has successfully negotiated a TID-to-link mapping with the AP MLD and the AP MLD has buffered traffic having TIDs that are not mapped to all enabled links of the at least one non-AP MLD.

[0008] In some embodiments, the processor is configured to generate the multi-link traffic indication element when the AP MLD intends to provide a link recommendation for retrieving buffered traffic to at least one non-AP MLD.

[0009] In some embodiments, the processor is configured to refrain from generating the multi-link traffic indication element when the AP MLD does not intend to provide a link recommendation for retrieving buffered traffic to any associated non-AP MLD, and when the AP MLD does not have buffered traffic for a TID that maps to only a subset of enabled links of any associated non-AP MLD.

[0010] In some embodiments, the multi-link traffic indication element includes a recommendation field indicating at least one non-AP MLD for which the AP MLD provides per-link traffic indications to retrieve buffered traffic. The per-link traffic indications include link recommendations or traffic indications.

[0011] In some embodiments, the recommendation field includes a set of bits. Starting from the offset number of the traffic indication virtual bitmap in the TIM element, each bit corresponds to a corresponding one of the associated non-AP MLD and non-AP station (STA). Each bit indicates whether the AP MLD provides per-link traffic indication for the corresponding non-AP MLD or non-AP STA.

[0012] In some embodiments, the recommendation field includes a set of bits. Each bit corresponds to a corresponding one of the associated non-AP MLDs and non-AP STAs indicated as having buffered traffic in a traffic indication virtual bitmap of a TIM element, the traffic indication virtual bitmap of the TIM element starting from an offset number of the traffic indication virtual bitmap in the TIM element. Each bit indicates whether the AP MLD provides per-link traffic indication for the corresponding non-AP MLD or non-AP STA.

[0013] In some embodiments, the multi-link traffic indication element optionally includes a recommendation field, and the multi-link traffic indication element includes a recommendation present field, which indicates whether the recommendation field is present in the multi-link traffic indication element.

[0014] In some embodiments, the multi-link traffic indication element includes one or more per-link traffic indication fields, each field providing a link recommendation or traffic indication for a corresponding one of the at least one non-AP MLD.

[0015] In some embodiments, a multi-link traffic indication element is included in a group addressed frame and is not associated with a TIM element, including a recommendation field indicating at least one non-AP MLD for which the AP MLD provides per-link traffic indication to retrieve buffered traffic.

[0016] One embodiment of the present disclosure may provide a non-AP MLD associated with a wireless network. The non-AP MLD includes at least two stations attached to the non-AP MLD and a processor coupled to the at least two STAs. The processor is configured to: receive a traffic indication map (TIM) element included in a beacon frame from an AP MLD associated with the non-AP MLD. The TIM element indicates the suspended buffered traffic of the non-AP MLD. The processor is configured to determine whether a multi-link traffic indication element is present in the beacon frame. Based on whether all multiple non-AP MLDs associated with the AP MLD have a default traffic identifier (TID) to link mapping and whether the AP MLD has buffered traffic, the buffered traffic has a TID mapped to all enabled links of the associated non-AP MLD. The processor is configured to determine whether there is a per-link traffic indication for the non-AP MLD in the multi-link traffic indication element when the multi-link traffic indication element is present, the per-link traffic indication providing a traffic indication or a link recommendation to retrieve the buffered traffic for the non-AP MLD. The processor is configured to: when there is a per-link traffic indication for the non-AP MLD, send a trigger frame to the AP MLD to retrieve buffered traffic via the link indicated in the per-link traffic indication. The processor is configured to receive buffered traffic from the AP MLD via the link indicated in the per-link traffic indication.

[0017] In some embodiments, the multi-link traffic indication element is present in the beacon frame when at least one of the associated non-AP MLDs has successfully negotiated TID-to-link mapping with the AP MLD and the AP MLD has buffered traffic with TIDs that are not mapped to all enabled links of the associated non-AP MLDs.

[0018] In some embodiments, the multi-link traffic element is present in the beacon frame when the AP MLD intends to provide a link recommendation to at least one associated non-AP MLD to retrieve buffered traffic.

[0019] In some embodiments, when the AP MLD does not intend to provide link recommendations to any associated non-AP MLDs, and when the AP MLD does not have buffered traffic whose TIDs are mapped to only a subset of enabled links of any associated non-AP MLDs, the multi-link traffic indication element is not present in the beacon frame.

[0020] In some embodiments, the multilink traffic indication element includes a recommendation field indicating at least one non-AP MLD for which the AP MLD provides per-link traffic indication. The processor is configured to determine whether the per-link traffic indication of the non-AP MLD is present in the multilink traffic indication element based on the recommendation field.

[0021] In some embodiments, the recommendation field includes a set of bits. Starting from the offset number of the traffic indication virtual bitmap in the TIM element, each bit corresponds to a corresponding one of the associated non-AP MLD and non-AP station (STA). Each bit indicates whether the AP MLD provides per-link traffic indication for the corresponding non-AP MLD or non-AP STA.

[0022] In some embodiments, the recommendation field includes a set of bits. Each bit corresponds to a corresponding one of the associated non-AP MLDs and non-AP STAs indicated as having buffered traffic in a traffic indication virtual bitmap in a TIM element, the traffic indication virtual bitmap in the TIM element starting from an offset number of the traffic indication virtual bitmap in the TIM element. Each bit indicates whether the APMLD provides per-link traffic indication for the corresponding non-AP MLD or non-AP STA.

[0023] In some embodiments, the multi-link traffic indication element optionally includes a recommendation field, and the multi-link traffic indication element includes a recommendation presence field, which indicates whether the recommendation field is present in the multi-link traffic indication element. The processor is further configured to determine whether the multi-link traffic indication element includes the recommendation field based on the recommendation presence field.

[0024] In some embodiments, the multiple traffic indication element includes one or more per-link traffic indication fields. Each field provides a link recommendation or traffic indication for a corresponding one of the at least one non-AP MLD.

[0025] In some embodiments, a multi-link traffic indication element is included in a group addressed frame and is not associated with a TIM element, comprising a recommendation field indicating at least one non-APMLD for which the AP MLD provides per-link traffic indication. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 An example of a wireless network according to an embodiment is shown.

[0027] Figure 2a An example of an AP according to an embodiment is shown.

[0028] Figure 2b An example of a STA according to an embodiment is shown.

[0029] Figure 3 An example of a multi-link communication operation according to an embodiment is shown.

[0030] Figure 4 An example of a TID-to-link mapping element according to an embodiment is shown.

[0031] Figure 5a An example of a multi-link traffic indication element according to an embodiment is shown.

[0032] Figure 5b An example of construction of a multi-link traffic indication element according to an embodiment is shown.

[0033] Figure 6a Another example of a multi-link traffic indication element according to an embodiment is shown.

[0034] Figure 6b and Figure 6c Another example of construction of a multi-link traffic indication element according to an embodiment is shown.

[0035] Figure 7a Another example of a multi-link traffic indication element according to an embodiment is shown.

[0036] Figure 7b and Figure 7c Another example of construction of a multi-link traffic indication element when a recommended partial virtual bitmap field is present according to an embodiment is shown.

[0037] Figure 8a Another example of a multi-link traffic indication element according to an embodiment is shown.

[0038] Figure 8b Another example of construction of a multi-link traffic indication element according to an embodiment is shown.

[0039] Fig. 9 Another example of construction of a multi-link traffic indication element according to an embodiment is shown.

[0040] Fig.10 An example of a process for indicating buffered traffic using a multi-link traffic indication element by an AP MLD according to an embodiment is shown.

[0041] Fig.11 Another example of a process for indicating buffered traffic using a multi-link traffic indication element by an AP MLD according to an embodiment is shown.

[0042] Fig.12 An example of a process for receiving a multi-link traffic indication element by a non-AP MLD according to an embodiment is shown.

[0043] In one or more embodiments, all of the components depicted in each figure may not be required, and one or more embodiments may include additional components not shown in the figures. The arrangement and type of components may be varied without departing from the scope of the present disclosure. Additional components, different components, or fewer components may be utilized within the scope of the present disclosure. DETAILED DESCRIPTION

[0044] The detailed description set forth below in conjunction with the drawings is intended to be a description of various embodiments, and is not intended to represent the only embodiment in which the subject technology can be practiced. On the contrary, the detailed description includes specific details for providing a thorough understanding of the subject of the present invention. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways, all without departing from the scope of the present disclosure. Therefore, the drawings and descriptions are considered to be illustrative and non-restrictive in nature. The same reference numerals represent the same elements.

[0045] For the purpose of describing the innovative aspects of the present disclosure, the following description is directed to certain embodiments. However, one of ordinary skill in the art will readily recognize that the teachings herein can be applied in a variety of different ways. The examples in the present disclosure are based on WLAN communications according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, including the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard. However, the described embodiments may be implemented in a manner capable of transmitting and receiving radio frequency (RF) signals in accordance with standards such as the IEEE 802.11 standard, the Bluetooth standard, Global System for Mobile Communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband CDMA (W-CDMA), Evolution-Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed ​​Packet Access (HSPA), High Speed ​​Downlink Packet Access (HSDPA), High Speed ​​Uplink Packet Access (HSUPA), Evolved High Speed ​​Packet Access (HSPA+), Long Term Evolution (LTE), 5G NR (New Radio), AMPS, or other known signals for communicating within a wireless, cellular, or Internet of Things (IoT) network, such as a system utilizing 3G, 4G, 5G, 6G, or further implementations thereof.

[0046] Figure 1 An example of a wireless network 100 according to an embodiment is shown. Figure 1 The embodiment of the wireless network 100 shown in FIG. 1 is for illustration purposes only. Other embodiments of the wireless network 100 may be used without departing from the scope of the present disclosure.

[0047] like Figure 1As shown, the wireless network 100 includes multiple wireless communication devices. Each wireless communication device may include one or more stations (STA). A STA may be a logical entity that is a separately addressable instance of a media access control (MAC) layer and a physical (PHY) layer interface to a wireless medium. A STA may be classified into an access point (AP) STA and a non-access point (non-AP) STA. An AP STA may be an entity that provides access to distribution system services via a wireless medium for associated STAs. A non-AP STA may be a STA that is not included in an AP-STA. To simplify the description, an AP STA may be referred to as an AP, and a non-AP STA may be referred to as a STA. In Figure 1 In the example of , APs 101 and 103 are wireless communication devices, each of which may include one or more AP STAs. In such an embodiment, APs 101 and 103 may be AP multi-link devices (MLDs). Similarly, STAs 111-114 are wireless communication devices, each of which may include one or more non-AP STAs. In such an embodiment, STAs 111-114 may be non-AP MLDs.

[0048] APs 101 and 103 communicate with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network. AP 101 provides wireless access to network 130 for multiple stations 111-114 having a coverage area 120 of AP 101. AP 101 and AP 103 may communicate with each other and with STAs using Wi-Fi or other WLAN communication technologies.

[0049] Depending on the network type, other well-known terms may be used instead of "access point" or "AP", such as "router" or "gateway". For convenience, the term "AP" is used in this disclosure to refer to a network infrastructure component that provides wireless access to a remote terminal. In a WLAN, assuming that the AP also competes for a wireless channel, the AP may also be referred to as a STA. In addition, depending on the network type, other well-known terms may be used instead of "station" or "STA", such as "mobile station", "subscriber station", "remote terminal", "user equipment", "wireless terminal" or "user device". For convenience, the terms "station" and "STA" are used in this disclosure to refer to remote wireless equipment that wirelessly accesses an AP or competes for a wireless channel in a WLAN, whether the STA is a mobile device (such as a mobile phone or smart phone) or is generally considered to be a fixed device (such as a desktop computer, AP, media player, fixed sensor, television, etc.).

[0050] exist Figure 1, the dashed lines show the approximate extents of the coverage areas 120 and 125 of APs 101 and 103, which are shown as approximately circular for purposes of illustration and explanation. It should be clearly understood that the coverage areas associated with APs, such as coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on the configuration of the APs.

[0051] As described in more detail below, one or more of the APs may include circuitry and / or programming for managing MU-MIMO and OFDMA channel sounding in a WLAN. Figure 1 One example of a wireless network 100 is shown, but may be Figure 1 Various changes may be made. For example, the wireless network 100 may include any number of APs and any number of STAs in any suitable arrangement. In addition, the AP 101 may communicate directly with any number of STAs and provide these STAs with wireless broadband access to the network 130. Similarly, each of the APs 101 and 103 may communicate directly with the network 130 and provide the STAs with direct wireless broadband access to the network 130. In addition, the APs 101 and / or 103 may provide access to other or additional external networks (such as an external telephone network or other types of data networks).

[0052] Figure 2a An example of an AP 101 according to an embodiment is shown. Figure 2a The embodiment of AP 101 shown in FIG. 1 is for illustrative purposes, and Figure 1 The APs 103 may have the same or similar configurations. However, APs have a wide range of configurations, and Figure 2a The scope of the present disclosure is not limited to any particular implementation of the AP.

[0053] like Figure 2a As shown, the AP 101 includes multiple antennas 204a-204n, multiple radio frequency (RF) transceivers 209a-209n, transmit (TX) processing circuitry 214, and receive (RX) processing circuitry 219. The AP 101 also includes a controller / processor 224, a memory 229, and a backhaul or network interface 234. The RF transceivers 209a-209n receive incoming RF signals from the antennas 204a-204n, such as signals transmitted by STAs in the network 100. The RF transceivers 209a-209n down-convert the incoming RF signals to generate intermediate (IF) or baseband signals. The IF or baseband signals are sent to the RX processing circuitry 219, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The RX processing circuitry 219 sends the processed baseband signals to the controller / processor 224 for further processing.

[0054] The TX processing circuit 214 receives analog or digital data (such as voice data, network data, email, or interactive video game data) from the controller / processor 224. The TX processing circuit 214 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceivers 209a-209n receive the outgoing processed baseband or IF signals from the TX processing circuit 214 and up-convert the baseband or IF signals to RF signals that are transmitted via the antennas 204a-204n.

[0055] The controller / processor 224 may include one or more processors or other processing devices that control the overall operation of the AP 101. For example, the controller / processor 224 may control the reception of uplink signals and the transmission of downlink signals by the RF transceivers 209a-209n, the RX processing circuit 219, and the TX processing circuit 214 according to well-known principles. The controller / processor 224 may also support additional functions, such as more advanced wireless communication functions. For example, the controller / processor 224 may support beamforming or directional routing operations, in which outgoing signals from multiple antennas 204a-204n are weighted differently to effectively guide the outgoing signals in the desired direction. The controller / processor 224 may also support OFDMA operations, in which outgoing signals are assigned to different subcarrier subsets of different recipients (e.g., different STAs 111-114). The controller / processor 224 may support any of a variety of other functions in the AP 101, including a combination of DL MU-MIMO and OFDMA in the same transmit opportunity. In some embodiments, the controller / processor 224 includes at least one microprocessor or microcontroller. The controller / processor 224 is also capable of executing programs and other processes, such as an OS, residing in the memory 229. The controller / processor 224 can move data into or out of the memory 229 as required by the executed process.

[0056] The controller / processor 224 is also coupled to a backhaul or network interface 234. The backhaul or network interface 234 allows the AP 101 to communicate with other devices or systems over a backhaul connection or over a network. The interface 234 can support communication over any suitable wired or wireless connection. For example, the interface 234 can allow the AP 101 to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The interface 234 includes any suitable structure that supports communication over a wired or wireless connection (such as Ethernet or an RF transceiver). The memory 229 is coupled to the controller / processor 224. A portion of the memory 229 may include RAM, and another portion of the memory 229 may include flash memory or other ROM.

[0057] As described in more detail below, AP 101 may include circuitry and / or programming for managing the channel sounding process in a WLAN. Figure 2a An example of AP 101 is shown, but the Figure 2a For example, AP101 may include Figure 2a . As a specific example, the AP may include multiple interfaces 234, and the controller / processor 224 may support routing functions to route data between different network addresses. As another example, although shown as including a single instance of TX processing circuitry 214 and a single instance of RX processing circuitry 219, the AP 101 may include multiple instances of each (such as one for each RF transceiver). Alternatively, for example, only one antenna and RF transceiver path may be included in a traditional AP. In addition, Figure 2a The various components in may be combined, further subdivided, or omitted, and additional components may be added according to specific needs.

[0058] like Figure 2a As shown, in some embodiments, the AP 101 may be an APMLD including a plurality of APs 202a-AP 202n. Each of the APs 202a-AP 202n is attached to the AP MLD 101 and includes a plurality of antennas 204a-204n, a plurality of radio frequency (RF) transceivers 209a-209n, a transmit (TX) processing circuit 214, and a receive (RX) processing circuit 219. Each of the APs 202a-AP 202n may independently communicate with the controller / processor 224 and other components of the AP MLD 101. Figure 2a Each of the APs 202a-202n is shown as having separate multiple antennas, but each of the APs 202a-202n may share multiple antennas 204a-204n instead of requiring separate multiple antennas. Each of the APs 202a-202n may represent a physical (PHY) layer and a lower medium access control (MAC) layer.

[0059] Figure 2b An example of STA 111 according to an embodiment is shown. Figure 2b The embodiment of STA 111 shown in FIG. 1 is for illustration purposes, and Figure 1 STAs 111-114 may have the same or similar configurations. However, STAs have a variety of configurations, and Figure 2b The scope of the present disclosure is not limited to any particular implementation of a STA.

[0060] like Figure 2bAs shown, STA 111 includes antenna 205, RF transceiver 210, TX processing circuit 215, microphone 220 and RX processing circuit 225. STA 111 also includes speaker 230, controller / processor 240, input / output (I / O) interface (IF) 245, touch screen 250, display 255 and memory 260. Memory 260 includes operating system (OS) 261 and one or more applications 262.

[0061] RF transceiver 210 receives incoming RF signals sent by APs of network 100 from antenna 205. RF transceiver 210 downconverts the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are sent to RX processing circuitry 225, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 225 sends the processed baseband signals to speaker 230 (such as for voice data) or to controller / processor 240 for further processing (such as for web browsing data).

[0062] The TX processing circuit 215 receives analog or digital voice data from the microphone 220, or receives other outgoing baseband data (such as network data, email, or interactive video game data) from the controller / processor 240. The TX processing circuit 215 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 210 receives the outgoing processed baseband or IF signal from the TX processing circuit 215 and up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna 205.

[0063] The controller / processor 240 may include one or more processors and execute a basic OS program 261 stored in the memory 260 to control the overall operation of the STA 111. In one such operation, the controller / processor 240 controls the RF transceiver 210, the RX processing circuit 225, and the TX processing circuit 215 to receive downlink signals and transmit uplink signals according to well-known principles. The controller / processor 240 may also include a processing circuit configured to provide management of the channel sounding process in the WLAN. In some embodiments, the controller / processor 240 includes at least one microprocessor or microcontroller.

[0064] The controller / processor 240 is also capable of executing other processes and programs resident in the memory 260, such as operations for managing the channel sounding process in the WLAN. The controller / processor 240 can move data into or out of the memory 260 as required by the executed process. In some embodiments, the controller / processor 240 is configured to execute multiple applications 262, such as applications for channel sounding, including feedback calculations based on received null data packet announcements (NDPA) and null data packets (NDP), and sending beamforming feedback reports in response to trigger frames (TFs). The controller / processor 240 can operate multiple applications 262 based on the OS program 261 or in response to signals received from the AP. The controller / processor 240 is also coupled to the I / O interface 245, which provides the STA111 with the ability to connect to other devices such as laptops and handheld computers. The I / O interface 245 is a communication path between these accessories and the main controller / processor 240.

[0065] The controller / processor 240 is also coupled to an input 250 (e.g., a touch screen) and a display 255. An operator of the STA 111 can use the input 250 to enter data into the STA 111. The display 255 can be a liquid crystal display, a light emitting diode display, or other display capable of presenting text and / or at least limited graphics, such as from a website. A memory 260 is coupled to the controller / processor 240. A portion of the memory 260 can include random access memory (RAM), and another portion of the memory 260 can include flash memory or other read-only memory (ROM).

[0066] although Figure 2b An example of STA 111 is shown, but the Figure 2b Make various changes. For example, Figure 2b The various components in the 240 may be combined, further subdivided, or omitted, and additional components may be added as required. In a specific example, the STA 111 may include any number of antennas 205 for MIMO communication with the AP 101. In another example, the STA 111 may not include voice communications, or the controller / processor 240 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In addition, although Figure 2b The STA 111 is shown configured as a mobile phone or smart phone, but the STA may be configured to operate as other types of mobile or stationary devices.

[0067] like Figure 2bAs shown, in some embodiments, STA 111 may be a non-AP MLD including a plurality of STAs 203a-203n. Each of STA 203a-203n is attached to non-AP MLD 111 and includes an antenna 205, an RF transceiver 210, a TX processing circuit 215, and an RX processing circuit 225. Each of STA 203a-203n may independently communicate with the controller / processor 240 and other components of non-AP MLD 111. Figure 2b Each of the STA 203a-STA 203n is shown as having a separate antenna, but each of the STA 203a-203n may share antenna 205 without requiring a separate antenna. Each of the STA 203a-STA 203n may represent a physical (PHY) layer and a lower medium access control (MAC) layer.

[0068] Figure 3 An example of a multi-link communication operation according to an embodiment is shown. The multi-link communication operation can be used in the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard. Figure 3 In the example, the AP MLD 310 can be Figure 1 The wireless communication devices 101 and 103 in the embodiment, and the non-AP MLD 220 may be Figure 1 One of the wireless communication devices 111-114 in.

[0069] like Figure 3 As shown, AP MLD 310 may include multiple subordinate APs, for example, including AP 1, AP 2, and AP 3. Each subordinate AP includes a PHY interface to a wireless medium (Link 1, Link 2, or Link 3). AP MLD 310 includes a single MAC service access point (SAP) 318, and the subordinate APs of AP MLD 310 communicate with a higher layer (Layer 3 or network layer) through SAP 318. Each subordinate AP of AP MLD 310 may have a different MAC address (lower MAC address) from any other subordinate AP of AP MLD 310. AP MLD 310 may have an MLD MAC address (upper MAC address), and the subordinate APs share a single MAC SAP 318 to Layer 3. Therefore, the subordinate APs share a single IP address, and Layer 3 identifies AP MLD 310 by assigning a single IP address.

[0070] The non-AP MLD 320 may include a plurality of subordinate STAs, for example, including STA 1, STA 2, and STA 3. Each subordinate STA includes a PHY interface to a wireless medium (Link 1, Link 2, or Link 3). The non-AP MLD 320 includes a single MAC SAP 328 through which the subordinate STAs of the non-AP MLD 320 communicate with a higher layer (Layer 3 or Network Layer). Each subordinate STA of the non-AP MLD 320 may have a MAC address (low MAC address) different from any other subordinate STA of the non-AP MLD 320. The non-AP MLD 320 may have an MLD MAC address (high MAC address), and the subordinate STAs share a single MACSAP 328 to Layer 3. Therefore, the subordinate STAs share a single IP address, and Layer 3 identifies the non-AP MLD 320 by assigning a single IP address.

[0071] The AP MLD 310 and the non-AP MLD 320 may establish multiple links between their subordinate APs and STAs. In this example, AP 1 and STA 1 may establish Link 1 operating in the 2.4 GHz band. Similarly, AP 2 and STA 2 may establish Link 2 operating in the 5 GHz band, and AP 3 and STA 3 may establish Link 3 operating in the 6 GHz band. Each link may independently enable channel access and frame exchange between the AP MLD 310 and the non-AP MLD 320, which may increase data throughput and reduce latency.

[0072] In order to prioritize the transmission of different types of traffic identified by traffic identifiers (TIDs) on established links, the non-AP MLD 320 may negotiate a TID-to-link mapping with the AP MLD 310. The TID-to-link mapping allows the APMLD 310 and the non-AP MLD 320 to determine how frames belonging to a TID are allocated for transmission on each established link in the uplink and downlink directions, respectively. When at least one TID associated with the non-AP MLD 320 is mapped to an established link in either the uplink or downlink direction, the link is referred to as an enabled link of the non-AP MLD 320. By default, all TIDs are mapped to all established links between the AP MLD 310 and the non-AP MLD 320, and the mapping is referred to as a default TID-to-link mapping. During association, the non-AP MLD 320 may negotiate a non-default mapping of TIDs to established links using a negotiation process by including a TID-to-link mapping element in an association request frame or a reassociation request frame. The non-default mapping may be the case where all TIDs are mapped to the same subset of established links, or the case where not all TIDs are mapped to the same subset of established links. The AP MLD 310 may also use a broadcast procedure to indicate a switch to a non-default mapping for all associated non-AP MLDs. In the default mapping mode, all TIDs are mapped to all established links for downlinks and uplinks, and all established links are enabled. When TID-to-link mapping negotiation does not occur or is unsuccessful, the non-AP MLD 320 operates in the default mapping mode.

[0073] Figure 4 An example of a TID-to-link mapping element 400 is shown according to an embodiment. Figure 4 This example may be applicable to the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard. The TID-to-link mapping element 400 may indicate the links on which frames belonging to each TID may be exchanged.

[0074] like Figure 4 As shown, the TID to link mapping element 400 may include an element ID field, a length field, an element ID extension field, a TID to link mapping control field, a mapping switch time field, an expected duration field, and an optional link mapping field for TID n.

[0075] The element ID field and the element ID extension field may include information for identifying the TID-to-link mapping element 400. The length field may indicate the length of the TID-to-link mapping element 400.

[0076] The TID to link mapping control field may include a direction subfield, a default link mapping subfield, a mapping switch time existence subfield, an expected duration existence subfield, a link mapping size subfield, a reserved subfield, and an optional link mapping existence indicator subfield. The direction subfield may indicate whether the TID to link mapping element 400 is for a downlink frame, an uplink frame, or both. For example, for a downlink frame, the direction subfield may be set to 0, for an uplink frame, the direction subfield may be set to 1, and for a frame sent on both the downlink and the uplink, the direction subfield may be set to 2. The default link mapping subfield may indicate whether the TID to link mapping element 400 represents a default TID to link mapping. For example, for a default mapping, the subfield may be set to 1, and for a non-default mapping, the subfield may be set to 0. The mapping switch time existence subfield may indicate whether the mapping switch time field exists in the TID to link mapping element 400. The expected duration existence subfield may indicate whether the expected duration field exists in the TID to link mapping element 400. The link mapping size subfield may indicate the length field of the link mapping of TID n. The link map presence indicator subfield may indicate whether a link map field for TID n exists in the TID to link map element 400 .

[0077] The Mapping Switch Time field is present when the TID-to-Link Mapping element 400 is sent in a beacon or probe response frame by an AP attached to an AP MLD and the indicated TID-to-link mapping has not yet been established.

[0078] The expected duration field may indicate the duration for which the proposed TID-to-link mapping is expected to be valid when the mapping switch time field is present, and the remaining duration for which the proposed TID-to-link mapping is expected to be valid when the mapping switch time field is not present.

[0079] The Link Mapping for TID n field (e.g., where n=0, 1, ..., 7) may indicate links on which frames belonging to TID n are allowed to be sent. The Link Mapping for TID n field may carry a bitmap of links to which TID n is mapped. The Link Mapping for TID n field may not be present when the Default Link Mapping subfield of the TID to Link Mapping Control field indicates a default TID to link mapping. For example, when the Direction subfield is set to 0, the Default Link Mapping subfield is set to 0, and the Link Mapping for TID 0 field is configured as 10000...0, the configuration indicates that downlink data corresponding to TID 0 is sent on Link 1.

[0080] The TID-to-link mapping element 400 may be included in various management frames, such as a beacon frame, an association request / response frame, a reassociation request / response frame, or a probe response frame.

[0081] To allow non-AP MLDs to save power, several power management schemes may exist. For example, a STA of a non-AP MLD may be in a doze state for an extended period of time during which it is not expected to be able to send or receive frames. During this time, the corresponding AP of the AP MLD may buffer buffer-able units (BUs) (buffered BUs or buffered traffic) addressed to the STA of the non-AP MLD. In order to indicate the presence of pending BUs to all associated non-AP MLDs via broadcast or multicast signaling, each AP attached to the AP MLD periodically includes a traffic information map (TIM) element in the beacon frames it sends, and each AP attached to the AP MLD may optionally send a separate periodic broadcast TIM frame. In multi-link operation, the AP of the AP MLD may include a multi-link traffic indication element in the beacon frame to indicate the link on which the buffered BUs (or buffered traffic) may be retrieved. A BU may be a medium access control (MAC) service data unit (MSDU), an aggregated MAC service data unit (MSDU) [quality of service (QoS) station (STA) only], or a bufferable MAC management protocol data unit (MMPDU). A BU may be buffered to operate in a power saving mode. In this disclosure, the terms 'buffered traffic' and 'buffered BU' are used interchangeably and have the same meaning.

[0082] Figure 5a An example of a multi-link traffic indication element according to an embodiment is shown. This example may be applicable to the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard.

[0083] like Figure 5a As shown, the multi-link traffic indication element 500 may include an element ID field, a length field, an element ID extension field, a multi-link traffic indication control field, and a per-link traffic indication list field.

[0084] The element ID field and the element ID extension field may include information for identifying the multi-link traffic indication element 500. The length field may indicate the length of the multi-link traffic indication element 500.

[0085] The multi-link traffic indication control field may include a bitmap size subfield, an association identifier (AID) offset subfield, and a reserved subfield. The bitmap size subfield may indicate the size of each per-link traffic indication bitmap subfield in the per-link traffic indication list field. The AID offset subfield may indicate the k-numbered bit of the traffic indication virtual bitmap in the TIM. The traffic indication virtual bitmap indicates that there is pending traffic for a specific STA or non-AP MLD at the AP MLD.

[0086] The per-link traffic indication list field may include a plurality of per-link traffic indication bitmap subfields and a padding subfield. The per-link traffic indication bitmap subfield may indicate per-link traffic indication of a non-AP MLD that has negotiated TID-to-link mapping with the AP MLD, and not all TIDs are mapped to all enabled links. In an embodiment, the per-link traffic indication bitmap subfield may indicate a link recommendation to retrieve buffered traffic for a non-AP MLD that has negotiated TID-to-link mapping with the AP MLD, where all TIDs are mapped to all enabled links. In an embodiment, the per-link traffic indication bitmap subfield may indicate a link recommendation to retrieve buffered traffic for at least one non-AP MLD in a default mapping mode. The padding subfield may include padding bits to make the per-link traffic indication list field a multiple of 8 bits.

[0087] Figure 5b An example of construction of a multi-link traffic indication element according to an embodiment is shown.

[0088] exist Figure 5b , the traffic indication virtual bitmap shown in the top and middle parts and the partial virtual bitmap subfield in the TIM element show how to indicate the AIDs of the associated non-AP MLDs and STAs. The AP attached to the AP MLD can use the partial virtual bitmap of the TIM element to indicate the pending buffered traffic of the non-AP MLDs and STAs associated with the AP MLD. The partial virtual bitmap subfield in the TIM element can include a portion of the traffic indication virtual bitmap shown in the top. The AP attached to the APMLD should include the multilink traffic indication element 500 in the beacon frame, which is Figure 5b The bottom portion is shown.

[0089] As explained, the multilink traffic indication element 500 may include a per-link traffic indication bitmap subfield corresponding to the AID of the non-AP MLD or STA, starting from the bit number k of the traffic indication virtual bitmap indicated in the AID offset subfield in the multilink traffic indication element 500. The order of the per-link traffic indication bitmap subfields may follow the order of the bits set to 1 in the partial virtual bitmap subfield in the TIM element. If the non-AP MLD has a non-default TID-to-link mapping with the AP MLD, then if the AP MLD has a buffered BU or a media access control (MAC) management protocol data unit (MMPDU) while the TID is mapped to the link for the non-AP MLD, then the bit position i of the per-link traffic indication bitmap subfield for link ID i may be set to 1, otherwise the bit should be set to 0. If the non-AP MLD is in the default mapping mode, then if the AP MLD has a buffered BU or MMPDU and the non-AP MLD can use link i to retrieve the buffered BU or MMPDU, then the bit position i of the per-link traffic indication bitmap subfield for link ID i may be set to 1. Therefore, the AP MLD may provide a link recommendation to the non-AP MLD to retrieve buffered traffic (BU or MMPDU) using one or more enabled links.

[0090] exist Figure 5b In the example of , the first, third, fourth, and sixth AIDs in the partial virtual bitmap subfield in the TIM are set to 1, starting from the bit number k of the traffic indication virtual bitmap indicated in the AID offset subfield. The per-link traffic indication bitmap subfields correspond to the first, third, fourth, and sixth AIDs in the partial virtual bitmap subfield in ascending order. The first per-link traffic indication bitmap subfield can indicate in AID k that the AP MLD has pending buffered traffic in link 0. Therefore, the non-AP MLD with AID k can use link 0 to retrieve pending buffered traffic. The remaining per-link traffic indication bitmap subfields indicate recommended links in a similar manner.

[0091] In some embodiments, the AP MLD may not provide link recommendations for many non-AP MLDs. For example, this may occur in the case of an AID with a default TID to link mapping or with a non-default mapped AID, but the pending BU is mapped to all enabled links. The same is true for individually addressed management frames mapped to all established links. In such cases, the transmission of the multi-link traffic indication element 500 may be avoided.

[0092] In an embodiment, if all associated non-AP MLDs for which there are buffered BUs have at least one link to which all TIDs are mapped, the AP MLD may not provide the multilink traffic indication element 500 in the beacon frame. In addition, if all associated non-AP MLDs for which there are buffered BUs have default TID-to-link mapping or all TIDs are mapped to the same subset of links, the AP MLD may not provide the multilink traffic indication element in the beacon frame. Therefore, when at least one of the associated non-AP MLDs has successfully negotiated TID-to-link mapping and the AP MLD has buffered BUs with TIDs that are not mapped to all enabled links of the non-AP MLD, the AP affiliated with the AP MLD may include the multilink traffic indication element 500 in the beacon frame. Therefore, the non-AP MLD may selectively include the multilink traffic indication element 500, thereby helping to solve the beacon bloating problem.

[0093] In some implementations, there may be a mechanism for the AP MLD in default mapping mode to indicate to the non-AP MLD that the APMLD does not have any link recommendations for the non-AP MLD. In some implementations, there may also be a mechanism for the AP MLD in non-default mapping mode to indicate to the non-AP MLD whether pending BUs can be acquired or retrieved from any established link.

[0094] In an embodiment, when the non-AP MLD has negotiated a non-default TID-to-link mapping, but pending buffered flows in the AP MLD are mapped to all enabled links, the AP MLD may perform any of the following actions: i) set all bits of the per-link flow indication bitmap subfield corresponding to the AID of the non-AP MLD in the multi-link flow indication element to 0, indicating that all buffered flows may be obtained from any enabled link; or ii) set the bit corresponding to link i of the AID of the non-AP MLD in the per-link flow indication bitmap subfield of the multi-link flow indication element to 1, indicating that buffered flows may be obtained from link i. When at least one pending flow in the AP MLD for the non-AP MLD is not mapped to all enabled links, the AP MLD may not set all bits of the per-link flow indication bitmap subfield corresponding to the AID of the non-AP MLD in the multi-link flow indication element to 0. When a STA of a non-AP MLD in non-default TID-to-link mapping mode receives a TIM element with the bit corresponding to its AID set to 1, and in addition, all bits in the per-link traffic indication bitmap subfield corresponding to its AID in the multi-link traffic indication element may be set to 0, any STA of the non-AP MLD operating on the enabled link may send a PS (Power Save)-Poll frame or a U-APD (Unscheduled Automatic Power Save Delivery) Trigger frame (if the STA is using U-APD and delivery is enabled for all access categories) to retrieve all buffered BUs from the AP MLD.

[0095] In one embodiment, the AP MLD may set all bits in the per-link traffic indication bitmap subfield corresponding to the AID of the non-AP MLD to indicate to the non-AP MLD that "most" pending BUs can be acquired from any enabled link. In one embodiment, the AP MLD may use, for example, an "all zero" indication for the non-AP MLD in the default TID-to-link mapping mode to indicate that the AP MLD does not have a recommended link for the non-AP MLD to use to acquire buffered BUs.

[0096] In some embodiments, unnecessary reserved bits for indicating recommended links may be wasteful and undesirable. This may result in a very large size of the multi-link traffic indication element 500, which may reduce efficiency and may make it difficult to fit these bits within the beacon frame. Therefore, a mechanism is needed to effectively indicate recommended links to obtain buffered BUs only for non-AP MLDs for which the AP MLD has link recommendations.

[0097] Figure 6a Another example of a multi-link traffic indication element 600 according to an embodiment is shown. Figure 6b and Figure 6cAnother example of the construction of the multi-link traffic indication element according to the embodiment is shown. This example can be applicable to the IEEE 802.11be standard and any future revision of the IEEE 802.11 standard.

[0098] like Figure 6a As shown, the multi-link traffic indication element 600 may include an element ID field, a length field, an element ID extension field, a multi-link traffic indication control field, a recommended partial virtual bitmap field, and a per-link traffic indication list field. The multi-link traffic indication control field may include a bitmap size subfield, an AID offset subfield, and a reserved subfield.

[0099] In some aspects, the various fields or subfields in the multi-link traffic indication element 600 may be Figure 5a The corresponding fields or subfields in the multi-link traffic indication element 500 in FIG. 6 are the same or similar, with examples of differences described below. For example, the multi-link traffic indication element 600 may include an additional field referred to as a recommended partial virtual bitmap field.

[0100] Reference Figure 6a and Figure 6b , the AID Offset subfield in the multi-link traffic indication element 600 may indicate the bit number k of the traffic indication virtual bitmap. The Recommended Partial Virtual Bitmap field may have bits for all AIDs in the Partial Virtual Bitmap subfield of the TIM element, starting from AID k indicated in the AID Offset subfield. The bit for a specific AID may be set to 1 only when the AP MLD has a pending BU for the AID and the AP MLD has a recommended link for retrieving the pending BU. Otherwise, the bit for the AID may be set to 0. For a non-MLD STA or non-AP MLD with a single enabled link, this bit may always be set to 0.

[0101] It is recommended that the length of the Partial Virtual Bitmap field (excluding zero padding) be the same as the length of the Partial Virtual Bitmap subfield in the TIM element, such as Figure 6b In one embodiment, zero padding may be used to make the length of the field a multiple of 8 bits. In one embodiment, the multi-link traffic indication element 600 may additionally have a recommended partial virtual bitmap length field, indicating the length of the recommended partial virtual bitmap field (in 8 bits).

[0102] The per-link traffic indication list field in the multi-link traffic indication element 600 may be in the same format as Figure 5a and Figure 5b A similar approach as shown in includes multiple per-link traffic indication bitmap subfields and padding subfields. The per-link traffic indication bitmap subfield may correspond to the AID of the non-AP MLD and STA and be set to 1, starting from bit number k of the traffic indication virtual bitmap, such as Figure 6b The per-link traffic indication list field may contain l per-link traffic indication bitmap subfields, where l is the number of bits corresponding to the AIDs of non-AP MLDs and STAs in the recommended portion virtual bitmap field of the multi-link traffic indication element 600 and set to 1 starting from AID k.

[0103] exist Figure 6b In the example of , there are 4 bits set to 1 in the partial virtual bitmap subfield in the TIM element corresponding to 4 AIDs (i.e., AID k, AID k+2, AID k+3, and AID k+5). However, only 2 bits corresponding to 2 AIDs (i.e., AID k and AID k+5) are set to 1 in the recommended partial virtual bitmap because the AP MLD does not have link recommendations for AID k+2 and AID k+3, which are set to 1 in the partial virtual bitmap. As a result, the per-link traffic indication list field contains only two per-link traffic indication bitmap subfields, which correspond to AID k and AID k+5, which are set to 1 in the recommended partial virtual bitmap. The first per-link traffic indication bitmap subfield indicates link 0 as a recommended link for a non-AP MLD having AID k, and the second per-link traffic indication bitmap subfield indicates link 1 as a recommended link for a non-AP MLD having AID k+5 by setting the bit corresponding to the recommended link to 1 and the other bits to 0.

[0104] In an embodiment, the recommended partial virtual bitmap field may be carried in an information element or frame different from the multilink traffic indication element 600. For example, it may be carried in a TIM element or in an EHT action frame.

[0105] Figure 6c Another example of construction of a multi-link traffic indication element according to an embodiment is shown. Figure 6c This example uses reference Figure 6a and Figure 6b The multi-link traffic indication element 600 is depicted, with examples of differences being described below.

[0106] The length of the Recommended Partial Virtual Bitmap field may be equal to the number of bits l (excluding zero padding) corresponding to the AIDs of the non-AP MLDs or STAs and set to 1 starting from bit number k of the Partial Virtual Bitmap subfield of the TIM element. The order of the bits in the Recommended Partial Virtual Bitmap field may follow the order of the AID bits of the non-AP MLDs or STAs set to 1 in the Partial Virtual Bitmap of the TIM element. Figure 6cIn the example, if AID k+3 is the third bit set to 1 in the partial virtual bitmap of the TIM element (counting from AID k), the third bit of the recommended partial virtual bitmap field in the multi-link traffic indication element 600 corresponds to AID k+3. The length of the recommended partial virtual bitmap field can be inferred from the number of bits set to 1 in the partial virtual bitmap of the TIM element, starting from AID k. In an embodiment, zero padding can be used to make the length of this field a multiple of 8 bits. In one embodiment, the multi-link traffic indication element 600 may additionally have a recommended partial virtual bitmap length field, indicating the length of the recommended partial virtual bitmap field (in eight bits). In the example, the recommended partial virtual bitmap length field is inferred from the number of bits set to 1 in the partial virtual bitmap of the TIM element, starting from AID k. ... an embodiment, zero padding can be used to make the length of this field a multiple of 8 bits. In an embodiment, the multi-link traffic indication element 600 may additionally have a recommended partial virtual bitmap length field, indicating the length of the recommended partial virtual bitmap field (in eight bits). Figure 6c In the , the recommended length of the Partial Virtual Bitmap field is 4 bits excluding zero padding, while the length of the Partial Virtual Bitmap subfield in the TIM element is 6 bits, because counting from AID k, only 4 bits corresponding to 4 of the 6 AIDs (i.e., AID k, AID k+2, AID k+3, AID k+5) are set to 1. As a result, Figure 6b Compared with the embodiment, it is recommended that the length of the partial virtual bitmap field can be reduced by 2 bits.

[0107] The per-link traffic indication list field in the multi-link traffic indication element 600 may be in the same format as Figure 6b The similar manner shown in includes multiple per-link traffic indication bitmap subfields and padding subfields. The per-link traffic indication bitmap subfield corresponds to the AID of the non-AP MLD and STA and is set to 1, starting from the bit number k of the traffic indication virtual bitmap, such as Figure 6c The per-link traffic indication list field contains l per-link traffic indication bitmap subfields, where l is the number of bits corresponding to the AIDs of non-AP MLDs and STAs and set to 1 in the recommended partial virtual bitmap field of the multi-link traffic indication element 600.

[0108] exist Figure 6cIn the example of , there are 4 bits set to 1 in the partial virtual bitmap subfield in the TIM element corresponding to 4 AIDs (i.e., AID k, AID k+2, AID k+3, and AID k+5). However, only 2 bits corresponding to 2 AIDs (i.e., AID k and AID k+5) are set to 1 in the recommended partial virtual bitmap because the AP MLD does not have link recommendations for AID k+2 and AID k+3 set to 1 in the partial virtual bitmap. As a result, the per-link traffic indication list field contains only two per-link traffic indication bitmap subfields corresponding to AID k and AID k+5 set to 1 in the recommended partial virtual bitmap. The first per-link traffic indication bitmap subfield indicates link 0 as a recommended link for a non-AP MLD having AID k, and the second per-link traffic indication bitmap subfield indicates link 1 as a recommended link for a non-AP MLD having AID k+5 by setting the bit corresponding to the recommended link to 1 and the other bits to 0.

[0109] Figure 7a Another example of a multi-link traffic indication element 700 according to an embodiment is shown. This example may be used in the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard.

[0110] like Figure 7a As shown, the multi-link traffic indication element 700 may include an element ID field, a length field, an element ID extension field, a multi-link traffic indication control field, an optional recommended partial virtual bitmap field, and a per-link traffic indication list field. The multi-link traffic indication control field may include a bitmap size subfield, an AID offset subfield, and a recommended bitmap presence subfield.

[0111] In some aspects, the various fields or subfields in the multi-link traffic indication element 700 may be Figure 6a The corresponding fields or subfields in the multilink traffic indication element 600 in the multilink traffic indication control field are the same or similar, with examples of differences described below. For example, the multilink traffic indication element 700 may include an additional subfield in the multilink traffic indication control field, which is called the recommended bitmap exists subfield. The recommended bitmap exists subfield indicates whether an optional recommended partial virtual bitmap field exists. If the recommended partial virtual bitmap field exists, the recommended bitmap exists subfield is set to 1. Otherwise, the recommended bitmap exists subfield is set to 0.

[0112] Figure 7b Another example of the construction of the multi-link traffic indication element when the recommended partial virtual bitmap field is present according to an embodiment is shown. Figure 7bThe Recommended Bitmap Present subfield (B15) in the Multilink Traffic Indication Control field is set to 1 to indicate the presence of the optional Recommended Partial Virtual Bitmap field. The order of the AIDs and the indication of the recommended links in the Per-Link Traffic Indication List field is the same as Figure 6c The per-link traffic indication list field may contain l per-link traffic indication bitmap subfields, where l is the number of bits corresponding to the AIDs of non-AP MLDs and STAs and set to 1 in the recommended portion virtual bitmap field of the multi-link traffic indication element 700.

[0113] Figure 7c Another example of the construction of the multi-link traffic indication element when the recommended partial virtual bitmap field does not exist according to an embodiment is shown. Figure 7c The Recommended Bitmap Present subfield (B15) in the Multilink Traffic Indication Control field is set to 0 to indicate that the optional Recommended Partial Virtual Bitmap field is not present. The order of the AIDs and the indication of the recommended links in the Per-Link Traffic Indication List field is the same as Figure 5b The per-link traffic indication list field contains l per-link traffic indication bitmap subfields, where l is the number of bits corresponding to the AIDs of non-APMLDs and STAs and set to 1 starting from AID k in the partial virtual bitmap subfield of the TIM element included in the beacon frame with the multi-link traffic indication element.

[0114] The AP MLD may determine whether to include the recommended partial virtual bitmap field based on, for example, the number of AIDs with pending traffic and the number of AIDs for which the AP MLD has link recommendations for acquiring pending traffic.

[0115] When the Recommended Partial Virtual Bitmap field is present, if the non-AP MLD receives a TIM element with the Partial Virtual Bitmap of its AID set to 1 and a Multilink Traffic Indication element 700 with the Recommended Partial Virtual Bitmap of its AID set to 0, the non-AP MLD may not decode the rest of the Multilink Traffic Information element. In an embodiment, the non-AP MLD may use any enabled link to obtain pending BUs at the AP MLD. In an embodiment, the non-AP MLD may use any enabled link with all TIDs mapped thereto to obtain pending BUs at the AP MLD.

[0116] In an embodiment, if the Recommended Partial Virtual Bitmap field is present and the non-AP MLD receives the multi-link traffic indication element 700 with the Recommended Partial Virtual Bitmap set to 1 for its AID, or if the Recommended Partial Virtual Bitmap field is not present, the non-AP MLD may parse the Per-Link Traffic Indication List field to determine a recommended link list for the non-AP MLD.

[0117] In one embodiment, the recommended partial virtual bitmap field may be carried in an information element or frame different from the multilink traffic indication element 700. For example, it may be carried in a TIM element or in an EHT action frame.

[0118] Figure 8a Another example of a multi-link traffic indication element 800 according to an embodiment is shown. This example may be used in the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard.

[0119] like Figure 8a As shown, the multilink traffic indication element 800 may include an element ID field, a length field, an element ID extension field, a multilink traffic indication control field, an optional incremental AID list field, and a per-link traffic indication list field. The multilink traffic indication control field may include a bitmap size subfield, an AID offset subfield, and a traffic list format subfield.

[0120] In some aspects, the various fields or subfields in the multi-link traffic indication element 800 may be Figure 7a The corresponding fields or subfields in the multi-link traffic indication element 700 in FIG. 8 are the same or similar, with examples of differences described below. For example, the multi-link traffic indication element 800 may include an optional incremental AID list field instead of Figure 7a The multilink traffic indication element 700 may include an optional recommended partial virtual bitmap field in the multilink traffic indication element 700. In addition, the multilink traffic indication element 800 may include a traffic list format subfield in the multilink traffic indication control field instead of the recommended bitmap existence subfield. The traffic list format subfield may indicate whether there is an incremental AID list field. If the incremental AID list field exists, the traffic list format subfield may be set to 1. Otherwise, the traffic list format subfield may be set to 0.

[0121] If the Traffic List Format subfield is set to 0, the Incremental AID List field may not be present, and the Per-Link Traffic Indication List field may contain l Per-Link Traffic Indication Bitmap subfields, where l is the number of bits corresponding to the AIDs of non-AP MLDs and STAs and set to 1 in the Partial Virtual Bitmap subfield of the TIM element. The order of the AIDs and the indication of the recommended links in the Per-Link Traffic Indication List field may be the same as Figure 5b Same or similar.

[0122] If the Traffic List Format subfield is set to 1, the Incremental AID List field may be present and may indicate the AID list for which the AP MLD provides link recommendations to obtain pending BUs. In this embodiment, instead of indicating the actual AID value, only the incremental value relative to k is indicated. The size of each incremental AID value in bits may be , where m is the number of bits in the partial virtual bitmap subfield of the TIM element, starting from the bit corresponding to AID k. The per-link traffic indication list field may contain l per-link traffic indication bitmap subfields, where l is the number of bits corresponding to the AIDs of non-AP MLDs and STAs with incremental AID values ​​(relative to k) as indicated in the incremental AID list field. The number of per-link traffic indication bitmap subfields may be the same as the number of entries in the incremental AID list. A specific AID may be included in the incremental AID list field by the AP MLD, and accordingly, is included in the per-link traffic indication list field only when the AP MLD has a pending BU for the AID and the AP MLD provides a link recommendation for the AID to obtain buffered traffic. Otherwise, the AID may not be included in the incremental AID list field and the per-link traffic indication list field. AIDs corresponding to non-MLD STAs or non-AP MLDs with a single enabled link may always be excluded.

[0123] Figure 8b Another example of construction of a multi-link traffic indication element according to an embodiment is shown.

[0124] exist Figure 8b In the Incremental AID List Format field, there is a list of AIDs including AID k and AID k+5 in the Partial Virtual Bitmap subfield. Since there are no corresponding incremental values ​​for AID k+2 and AID k+3 even if the corresponding bits in the Partial Virtual Bitmap subfield are set to 1, there are no link recommendations for AID k+2 and AID k+3 in the Per-Link Traffic Indication List field. Therefore, the Per-Link Traffic Indication List field contains 2 Per-Link Traffic Indication Bitmap subfields because the Incremental AID List field has two bits corresponding to AID k and AID k+5.

[0125] In one embodiment, for any AID x, the incremental AID value may keep a count of the number of bits set to 1 between the bits for AID k and the bits corresponding to AID x, and the size in bits of each incremental AID value may be , where l is the number of bits set to 1 in the partial virtual bitmap of the TIM element.

[0126] In an embodiment, the length of each of the incremental AID values ​​in the incremental AID list format field may be indicated in a separate and optional incremental AID length field or subfield of the multilink traffic indication element.

[0127] If the non-AP MLD receives a TIM element whose partial virtual bitmap of AIDs is set to 1 and a multilink traffic indication element 800 in which the incremental AID list field does not contain its corresponding incremental value (relative to k), the non-AP MLD may not decode the remaining portion of the multilink traffic indication element 800. In this case, the non-AP MLD may use any one of its enabled links to obtain pending buffered BUs at the AP MLD. In one embodiment, the non-AP MLD may use any one of its enabled links to obtain pending buffered BUs at the AP MLD, the enabled links having all TIDs mapped to the enabled links.

[0128] In an embodiment, if the non-AP MLD receives the multi-link traffic indication element 800 in which the incremental AID list field contains its corresponding incremental value (relative to k), or if the traffic list format subfield is set to 0, the non-AP MLD may parse the per-link traffic indication list field to determine the link recommendation for the non-AP MLD.

[0129] In one embodiment, the incremental AID list fields may be carried in a different information element or frame than the multilink traffic indication element 800. For example, they may be carried in a TIM element or an EHT action frame.

[0130] Fig. 9 Another example of construction of a multi-link traffic indication element according to an embodiment is shown.

[0131] The multi-link traffic indication element may also be transmitted in an individual addressed or group addressed frame without an associated TIM element. In this example, the multi-link traffic indication element may be referred to as a "long term" multi-link traffic indication element.

[0132] Long-term multi-link flow indication elements can be used with Figure 6a The multi-link traffic indication element 600 in FIG. 1 is the same or similar, except that Fig. 9The AID Offset subfield indicating the number n is shown. The Recommended Part Virtual Bitmap field may have bits for all AIDs starting from AID f(n). Here, f(n) may be some function of n, such as 2n, 8n, or 16n. The bit for a particular AID in the Recommended Part Virtual Bitmap field may be set to 1 only when the AP MLD intends to provide a link recommendation for obtaining buffered suspended traffic to the non-AP MLD with the AID. Otherwise, the bit for the AID may be set to 0. In an embodiment, zero padding may be used to make the length of this field a multiple of 8 bits.

[0133] In an embodiment, the long-term multi-link traffic indication element may additionally have a recommended partial virtual bitmap length field to indicate the length of the recommended partial virtual bitmap field in units of octets.

[0134] A non-AP MLD that receives a long-term multi-link traffic indication element may use the recommended link set to obtain pending buffered traffic indicated in all subsequent TIM elements, unless the TIM element is accompanied by an associated multi-link traffic indication element that recommends an alternative link set to obtain the buffered traffic indicated in the TIM element. Thus, a long-term multi-link traffic indication element without an associated TIM element may be a "long-term" link recommendation indicated to the non-AP MLD.

[0135] The newly received long-term multi-link traffic indication element may replace the indication of the previous long-term multi-link traffic indication element for the non-AP MLD. If the link recommendation for the non-AP MLD is included in the new long-term multi-link traffic indication element and the bits for all links are set to 1, it may indicate that the previous long-term multi-link traffic indication element is destroyed or deactivated for the non-AP MLD. In one embodiment, if the link recommendation in the long-term multi-link traffic indication element is sufficient and valid for retrieving the buffered traffic for all associated non-AP MLDs for which buffered BUs exist, the APMLD may not provide the multi-link traffic indication element together with the TIM element in the beacon frame.

[0136] Fig.10 An example of a process 1000 for indicating buffered traffic using a multi-link traffic indication element by an AP MLD is shown according to an embodiment.

[0137] In operation 1001, the AP MLD determines whether the AP MLD has pending buffered traffic for a non-AP MLD having AID x. When the AP MLD has pending buffered traffic for the non-AP MLD having AID x, the process 1000 proceeds to operation 1003. In an embodiment, the process 1000 operates when the non-AP MLD associated with the AP MLD has negotiated a non-default TID-to-link mapping, but the pending buffered traffic at the AP MLD is mapped to all enabled links.

[0138] In operation 1003 , the AP MLD sets the bit corresponding to the AID x in the partial virtual bitmap subfield of the TIM element to 1. Then, the process 1000 proceeds to operation 1005 .

[0139] In operation 1005, the AP MLD determines whether all buffered traffic can be acquired from any enabled link by the non-AP MLD with AID x. When the non-AP MLD with AID x can acquire all buffered traffic from any enabled link, the process 1000 proceeds to operation 1007, otherwise proceeds to operation 1009.

[0140] In operation 1007, the AP MLD sets all bits corresponding to the AID x of the non-AP MLD in the per-link traffic indication bitmap subfield of the multi-link traffic indication element to 0. It indicates that all buffered traffic can be extracted from any enabled link of the non-AP MLD with AID x.

[0141] In operation 1009, the AP MLD does not set all bits corresponding to the AID x of the non-AP MLD in the per-link traffic indication bitmap subfield of the multi-link traffic indication element to 0. The AP MLD may set the bit corresponding to the link i of the non-AP MLD having the AID x in the per-link traffic indication bitmap subfield of the multi-link traffic indication element to 1 to indicate that the pending buffered traffic can be obtained from the link i.

[0142] Fig.11 Another example of a process 1100 for indicating buffered traffic using a multi-link traffic indication element by an AP MLD according to an embodiment is shown.

[0143] In operation 1101 , the AP MLD determines whether the AP MLD has pending buffered traffic for the non-AP MLD having AID x. When the AP MLD has pending buffered traffic for the non-AP MLD having AID x, the process 1100 proceeds to operation 1103 .

[0144] In operation 1103 , the AP MLD sets the bit corresponding to the AID x in the partial virtual bitmap subfield of the TIM element to 1. Then, the process 1100 proceeds to operation 1105 .

[0145] At operation 1105, the AP MLD determines whether to include an optional field in the multi-link traffic indication element. In an embodiment, the optional field may be a reference Figure 6a-Figure 9 The process 1100 may further include the following steps: The process 1101 may further include the following steps: The process 1102 may further include the following steps: The process 1103 may further include the following steps: The process 1104 may further include the following steps: The process 1105 may further include the following steps: The process 1106 may further include the following steps:

[0146] In operation 1107, the AP MLD determines whether it has a link recommendation for the non-AP MLD having AID x. When the APMLD has a link recommendation for the non-AP MLD having AID x, the process 1100 proceeds to operation 1109. Otherwise, proceeds to operation 1111.

[0147] At operation 1109, the AP MLD includes an optional field in the multi-link traffic indication element. For example, the optional field may be a recommended partial virtual bitmap field, a recommended partial virtual bitmap length field, a recommended bitmap existence subfield, an incremental AID list field, or a traffic list format subfield. In addition, the AP MLD includes the AID x of the non-AP MLD in the per-link traffic indication list field in the multi-link traffic indication element.

[0148] In operation 1111, the AP MLD includes an optional field in the multi-link traffic indication element. For example, the optional field may be a recommended partial virtual bitmap field, a recommended partial virtual bitmap length field, a recommended bitmap existence subfield, an incremental AID list field, or a traffic list format subfield. However, the AP MLD does not include the AID x of the non-AP MLD in the per-link traffic indication list field in the multi-link traffic indication element.

[0149] In operation 1113, the AP MLD includes the AID x of the non-AP MLD in the per-link traffic indication list field in the multi-link traffic indication element.

[0150] Fig.12 An example of a process 1200 for receiving a multi-link traffic indication element by a non-AP MLD is shown according to an embodiment.

[0151] In operation 1201, the non-AP MLD detects that the non-AP MLD receives a TIM element in a beacon frame, the TIM element indicating pending buffered traffic for the AID of the non-AP MLD. When the non-AP MLD receives the TIM element in the beacon frame, the process 1200 proceeds to operation 1203. Otherwise, proceed to operation 1211 and return to the snooze state.

[0152] In operation 1203 , the non-AP MLD determines whether a multi-link traffic indication element exists in the beacon frame. When the multi-link traffic indication element exists in the beacon frame, the process 1200 proceeds to operation 1205 . Otherwise, proceed to operation 1209 .

[0153] In operation 1205, the non-AP MLD determines whether there is a per-link traffic indication for the AID of the non-AP MLD. The per-link traffic indication may be present in a per-link traffic indication bitmap subfield within a per-link traffic indication list field of a multi-link traffic indication element. In one embodiment, the multi-link traffic indication element may include an optional field, for example, the optional field may be a recommended portion virtual bitmap field, a recommended portion virtual bitmap length field, a recommended bitmap existence subfield, an incremental AID list field, or a traffic list format subfield. The recommended portion virtual bitmap field and the incremental AID list field indicate the recommended link to the non-AP MLD. Therefore, the non-AP MLD may determine whether there is a per-link traffic indication for the AID of the non-AP MLD in the per-link traffic indication bitmap subfield based on the recommended portion virtual bitmap field and the incremental AID list field. When there is a per-link traffic indication for the AID of the non-AP MLD, the process 1200 proceeds to operation 1207. Otherwise, proceed to operation 1209.

[0154] In operation 1207, the non-AP MLD obtains the pending traffic at the AP MLD using the link indicated in the per-link traffic indication list field of the multi-link traffic indication element. The STA of the non-AP MLD operating on the link indicated in the per-link traffic indication list field may send a PS-Poll frame or a U-APD trigger frame to retrieve the buffered traffic from the AP MLD.

[0155] In operation 1209, the non-AP MLD acquires the pending buffered traffic at the AP MLD using the predetermined link list by sending a PS-Poll frame or a U-APD trigger frame to retrieve the buffered traffic from the AP MLD.

[0156] Unless otherwise specified, references to singular elements are not intended to mean one and only one, but rather one or more. For example, "a" module may refer to one or more modules. Without further limitation, an element preceded by "a", "an", "the" or "said" does not exclude the presence of additional identical elements.

[0157] Headings and subheadings, if any, are used for convenience only and do not limit the invention. The word "exemplary" is used to mean serving as an example or illustration. To the extent that the terms "including," "having," and the like are used, such terms are intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when used as a transitional word in the claims. Relational terms such as first and second, and the like may be used to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0158] Phrases such as aspect, aspect, another aspect, some aspects, one or more aspects, implementation, implementation, another implementation, some implementations, one or more implementations, embodiment, embodiment, one embodiment, some embodiments, one or more embodiments, configuration, configuration, another configuration, some configurations, one or more configurations, subject technology, the present disclosure, the present disclosure, other variations thereof, etc. are for convenience and do not imply that the disclosure associated with such phrases is essential to the subject technology or that such disclosure applies to all configurations of the subject technology. The disclosure associated with such phrases may apply to all configurations or one or more configurations. The disclosure associated with such phrases may provide one or more examples. Phrases such as aspect or some aspects may refer to one or more aspects and vice versa, and this applies similarly to the other aforementioned phrases.

[0159] The phrase "at least one of," preceding a list of items, where the terms "and" or "or" are used to separate any one of the items, modifies the list as a whole, rather than each member of the list. The phrase "at least one of" does not require selection of at least one of the items; rather, the phrase allows for a meaning that includes at least one of any one item and / or at least one of any combination of items and / or at least one of each item. For example, each of the phrases "at least one of A, B, and C" or "at least one of A, B, or C" means only A, only B, or only C; any combination of A, B, and C; and / or at least one of each of A, B, and C.

[0160] It should be understood that the specific order or hierarchy of steps, operations or processes disclosed is an illustration of an exemplary method. Unless otherwise explicitly stated, it should be understood that the specific order or hierarchy of steps, operations or processes can be performed in a different order. Some of the steps, operations or processes can be performed simultaneously or as part of one or more other steps, operations or processes. The attached method claims (if any) present the elements of various steps, operations or processes in a sample order and are not meant to be limited to the specific order or hierarchy presented. These can be performed serially, linearly, in parallel, or in different orders. It should be understood that the instructions, operations, and systems described can generally be integrated together in a single software / hardware product or packaged into multiple software / hardware products.

[0161] The present disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. In some instances, known structures and components are shown in block diagram form to avoid blurring the concept of the subject technology. The present disclosure provides various examples of the subject technology, and the subject technology is not limited to these examples. It will be apparent to those skilled in the art that various modifications to these aspects will be apparent, and the principles described herein can be applied to other aspects.

[0162] All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later become known to one of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element should be interpreted under the provisions of .C. §112, sixth paragraph, unless the element is explicitly recited using the phrase "means for..." or, in the case of a method claim, the phrase "step for..." is used to recite the element.

[0163] The title, background technology, figure description, abstract, and drawings are incorporated into the present disclosure and are provided as illustrative examples of the present disclosure rather than as limiting descriptions. It should be understood that the submitted abstract will not be used to limit the scope or meaning of the claims. In addition, in the specific implementation, it can be seen that the description provides illustrative examples, and various features are grouped together in various implementations for the purpose of simplifying the present disclosure. The method of the present disclosure should not be interpreted as reflecting the intention that the claimed subject matter requires more features than the features explicitly stated in each claim. On the contrary, as reflected in the following claims, the inventive subject matter lies in less than all the features of a single disclosed configuration or operation. The attached claims are incorporated into the specific implementation, wherein each claim itself is a subject matter claimed separately.

[0164] The claims are not intended to be limited to the aspects described herein, but are to be given the full scope consistent with the language of the claims and to encompass all legal equivalents. Nevertheless, the claims are not intended to encompass subject matter that does not satisfy applicable patent law requirements, nor should they be interpreted in such a manner.

Claims

1. An access point AP multi-link device MLD associated with a wireless network, the AP MLD comprising: At least two APs, attached to the AP MLD; as well as a processor, coupled to the at least two APs, the processor being configured to: generating a traffic indication map (TIM) element, the TIM element indicating pending buffered traffic for a plurality of non-AP MLDs associated with the AP MLD, selectively generating a multi-link traffic indication element based on determining whether all of the plurality of non-AP MLDs have a default traffic identifier TID to link mapping and whether the AP MLD has buffered traffic with TIDs mapped to all enabled links of at least one non-AP MLD, the multi-link traffic indication element including a per-link traffic indication for retrieving buffered traffic for the at least one non-AP MLD, generating a beacon frame including the TIM element and optionally including the multilink traffic indication element, and The beacon frame is sent to the plurality of non-AP MLDs.

2. The AP MLD according to claim 1, wherein: The processor is configured to generate the multi-link traffic indication element when at least one of the associated non-AP MLDs has successfully negotiated TID-to-link mapping with the AP MLD and the AP MLD has buffered traffic with TIDs that are not mapped to all enabled links of the at least one non-AP MLD.

3. The AP MLD according to claim 1 or 2, wherein the processor is configured to generate the multi-link traffic indication element when the AP MLD intends to provide a link recommendation for retrieving buffered traffic to the at least one non-AP MLD.

4. The AP MLD according to any one of the preceding claims, wherein: The processor is configured to refrain from generating the multi-link traffic indication element when the APMLD is not going to provide a link recommendation for retrieving buffered traffic to any of the associated non-AP MLDs, and when the AP MLD does not have buffered traffic with TIDs that map to only a subset of enabled links of any of the associated non-AP MLDs.

5. The AP MLD according to any one of the preceding claims, wherein: The multi-link traffic indication element includes a recommendation field, the recommendation field instructing the at least one non-APMLD for which the AP MLD provides the per-link traffic indication to retrieve buffered traffic, wherein the per-link traffic indication includes a link recommendation or a traffic indication.

6. A non-access point AP multi-link device MLD associated with a wireless network, the non-AP MLD comprising: At least two stations STA, attached to the non-AP MLD; as well as A processor is coupled to the at least two STAs, the processor being configured to: receiving a traffic indication map (TIM) element included in a beacon frame from an AP MLD associated with the non-AP MLD, the TIM element indicating pending buffered traffic for the non-AP MLD, determining whether a multi-link traffic indication element is present in the beacon frame, wherein the multi-link traffic indication element is selectively included in the beacon frame based on whether all of the plurality of non-AP MLDs associated with the AP MLD have a default traffic identifier TID to link mapping and whether the AP MLD has buffered traffic with TIDs mapped to all enabled links of the associated non-AP MLDs, When the multi-link traffic indication element is present, determining whether there is a per-link traffic indication for the non-AP MLD in the multi-link traffic indication element, the per-link traffic indication providing a traffic indication or a link recommendation for retrieving buffered traffic for the non-AP MLD, When there is a per-link traffic indication for the non-AP MLD, sending a trigger frame to the AP MLD to retrieve buffered traffic via a link indicated in the per-link traffic indication, and Buffered traffic is received from the AP MLD via the link indicated in the per-link traffic indication.

7. The non-AP MLD according to claim 6, wherein: The multi-link traffic indication element is present in the beacon frame when at least one of the associated non-AP MLDs has successfully negotiated TID-to-link mapping with the AP MLD and the AP MLD has traffic with TIDs that are not mapped to all enabled links of the associated non-AP MLDs.

8. The non-AP MLD according to claim 6 or 7, wherein: The multi-link traffic element is present in the beacon frame when the AP MLD intends to provide a link recommendation for retrieving buffered traffic to at least one associated non-AP MLD.

9. The non-AP MLD according to any one of claims 6 to 8, wherein: The multi-link traffic indication element is not present in the beacon frame when the AP MLD does not intend to provide link recommendations to any of the associated non-AP MLDs and when the AP MLD does not have buffered traffic with TIDs that map to only a subset of enabled links for any of the associated non-AP MLDs.

10. The non-AP MLD according to any one of claims 6 to 9, wherein: The multi-link traffic indication element includes a recommendation field, the recommendation field indicating at least one non-APMLD for which the AP MLD provides the per-link traffic indication, and The processor is configured to determine whether a per-link traffic indication for the non-AP MLD is present in the multi-link traffic indication element based on the recommendation field.

11. The non-AP MLD according to any one of claims 6 to 10, wherein: The recommendation field includes a bit set starting from an offset number of a traffic indication virtual bitmap in the TIM element, each bit corresponding to a corresponding one of an associated non-AP MLD and a non-AP station STA, wherein each bit indicates whether the AP MLD provides the per-link traffic indication for the corresponding non-AP MLD or non-AP STA.

12. The non-AP MLD according to any one of claims 6 to 11, wherein: The recommendation field includes a set of bits starting from an offset number of a traffic indication virtual bitmap in the TIM element, each bit corresponding to a corresponding one of an associated non-AP MLD and a non-AP STA indicated as having buffered traffic in the traffic indication virtual bitmap in the TIM element, wherein each bit indicates whether the AP MLD provides the per-link traffic indication for a corresponding non-AP MLD or non-AP STA.

13. The non-AP MLD according to any one of claims 6 to 12, wherein: The multi-link traffic indication element optionally includes the recommendation field, and the multi-link traffic indication element includes a recommendation presence field, the recommendation presence field indicating whether the recommendation field exists in the multi-link traffic indication element, and The processor is further configured to determine whether the multi-link traffic indication element includes the recommendation field based on the recommendation presence field.

14. The non-AP MLD according to any one of claims 6 to 13, wherein: The multiple traffic indication element includes one or more per-link traffic indication fields, each field providing a link recommendation or traffic indication for a corresponding one of the at least one non-AP MLD.

15. The non-AP MLD according to any one of claims 6 to 14, wherein: The multi-link traffic indication element is included in a group-addressed frame and is not associated with the TIM element, the multi-link traffic indication element comprising a recommendation field indicating at least one non-AP MLD for which the AP MLD provides the per-link traffic indication.

Images