Multi-access point coordination based on connection priority

Abstract

Methods, devices, and systems are provided to improve the operation of multi-connection devices. In one example, a device is designed to act as a first access point (AP) and perform operations that include: receiving, from a second AP, a first frame indicating the priority of a first connection among a multitude of connections, for the transmission of first-category traffic over the first connection by the second AP; and transmitting, over a second connection among the multitude of connections, a second frame containing second-category traffic, with the second connection being selected based on the priority of the first connection. The device can be designed to select the second connection for transmitting the second-category traffic.

Description

AREA

[0001] The present invention relates to wireless networks, in particular, but not limited to, those using local area network technologies such as IEEE 802.11. STATE OF THE ART

[0002] Modern wireless networks are often densely populated, and devices must be able to adapt to changing situations. In other words, flexibility is desirable even for complex devices. Requirements for low-latency data traffic can also lead to additional limitations. SUMMARY

[0003] The inventors have realized that when using multi-link devices (MLDs) and requiring low-latency data transmission, a situation can arise where two devices use multi-link connections. Specifically, the inventors have realized that problems can occur when an MLD non-AP STA receives a frame transmitted as an AP-to-AP frame over one of the multi-link connections. The STA may defer the transmission of potentially urgent (e.g., low-latency) data. In the case of IEEE 802.11, this may involve the STA terminating the NAV (Network Access Vehicle). Alternatively, the MLD STA may not receive the AP-to-AP frame and may proceed with a transmission that interferes with the AP-to-AP frame.

[0004] Accordingly, embodiments and aspects of the invention are defined in the accompanying claims.

[0005] In one aspect, a procedure is provided comprising receiving a first frame by a first access point (AP) from a second AP, which specifies the priority of a first connection from a plurality of connections, for transmitting first-category traffic by the second AP over the first connection; selecting a second connection from the plurality of connections by the first AP based on the priority of the first connection to transmit second-category traffic to the second AP; and transmitting a second frame, comprising the second-category traffic, by the first AP to the second AP over the second connection.

[0006] In one aspect, a procedure is provided comprising receiving, by a first access point (AP) from a second AP, a first frame that specifies the priority of a first connection of a plurality of connections for the transmission of first-category traffic over the first connection by the second AP; and transmitting, by the first AP, over a second connection of the plurality of connections, a second frame that includes second-category traffic, the second connection being selected based on the priority of the first connection.

[0007] According to one embodiment, transmitting the second frame includes transmitting the second frame to the second AP or to a first STA.

[0008] According to one embodiment, receiving the first frame includes receiving the first frame via the first connection or the second connection.

[0009] According to one embodiment, the priority of the first connection means that the second AP transmits only first-category traffic over the first connection.

[0010] According to one embodiment, the priority of the first connection means that the second AP does not transmit any first-category traffic over the first connection.

[0011] According to one embodiment, a data traffic stream of the first category is assigned to the first connection at the second AP.

[0012] According to one embodiment, the data traffic of the first category includes low-latency data traffic.

[0013] According to one embodiment, the data traffic of the first category includes the data traffic between the second AP and a second STA that is assigned to the second AP.

[0014] According to one embodiment, the data traffic of the second category includes the data traffic between the first AP and the second AP.

[0015] According to one embodiment, the first frame further specifies the priority of the second connection for the transmission of first-category traffic over the second connection by the second AP.

[0016] According to one embodiment, the first frame further includes a period for the transmission of first-category traffic over the first connection by the second AP.

[0017] According to one embodiment, the first frame includes a management frame.

[0018] According to one embodiment, the management frame includes a beacon frame with an element that specifies the priority of the first connection.

[0019] According to one embodiment, the management frame includes an action frame which includes an "Action" field that specifies the priority of the first connection.

[0020] According to one embodiment, a third frame is sent from the first AP to the second AP to request the first frame.

[0021] According to one embodiment, a fourth frame is sent from the first AP to the second AP as a response to the first frame.

[0022] According to one embodiment, the first AP and the second AP form a multi-AP group.

[0023] According to one embodiment, the first AP or the second AP or the APs comprise a multi-link device (MLD).

[0024] In one aspect, a device is designed to act as a first access point (AP) and to perform operations that include receiving, from a second AP, a first frame indicating the priority of a first connection among a multitude of connections, transmitting first-category traffic over the first connection through the second AP, and transmitting, over a second connection among the multitude of connections, a second frame comprising second-category traffic, the second connection being selected based on the priority of the first connection.

[0025] According to one embodiment, the device is designed to select the second connection for the transmission of the second category.

[0026] In one aspect, a system is provided that includes a device and a second AP as described herein.

[0027] In one aspect, a computer program product is provided that is stored on a computer-readable medium and, when executed on a processor, performs the procedure described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Examples of several of the different embodiments of the present disclosure are described herein with reference to the drawings. Fig. Figure 1 illustrates examples of wireless communication networks in which embodiments of the present disclosure can be implemented. Fig. Figure 2 is a block diagram illustrating example implementations of a station (STA) and an access point (AP). Fig. Figure 3 illustrates an example of a Medium Access Control Frame format (MAC frame format). Fig. Figure 4 illustrates an example management frame that can be used as an action frame. Fig. Figure 5 illustrates an example control frame that can be used as a trigger frame. Fig. Figure 6 illustrates an example data frame that can be used as a Quality of Service (QoS) null frame. Fig. Figure 7 illustrates an example format for a physical layer (PHY) protocol data unit (PPDU). Fig. Figure 8 illustrates an exemplary reference model for a multiple connection device (MLD). Fig. Figure 9 illustrates an example of an AP-MLD and an associated non-AP-MLD. Fig. Figure 10 illustrates an example of a multi-connect setup between an AP-MLD and a non-AP-MLD. Fig. Figure 11 illustrates an example of how to assign a traffic identifier (TID) to a connection in a multi-connection communication environment. Fig. Figure 12 illustrates an example of a multi-AP network. Fig. Figure 13 illustrates an example network that includes a coordinated AP set. Fig. Figure 14 illustrates an example of a multi-AP operational workflow. Fig. Figure 15 illustrates an exemplary multi-AP exploration phase. Fig. Figure 16 illustrates an example multi-AP downlink data transmission phase. Fig. Figure 17 illustrates an exemplary multi-AP uplink data transmission phase. Fig. Figure 18 illustrates an exemplary multi-AP information exchange phase. Fig. Figure 19 illustrates an example of a target wake-up time (TWT). Fig. Figure 20 illustrates an example of a multi-AP network that supports the multiple connection operation (MLO). Fig. Figure 21 illustrates an example of a multi-AP procedure in a multi-connection environment. Fig. Figure 22 illustrates an example of a multi-AP coordination procedure in a multi-connection environment according to one embodiment. Fig. Figure 23 illustrates a further example of a multi-AP coordination procedure in a multi-connection environment according to one embodiment. Fig. Figure 24 illustrates a further example of a multi-AP coordination procedure in a multi-connection environment according to one embodiment. Fig. Figure 25 illustrates a further example of a multi-AP coordination procedure in a multi-connect environment according to embodiments. Fig. Figure 26 illustrates an exemplary beacon frame that can be used according to embodiments. Fig. Figure 27 illustrates an exemplary action frame that can be used according to embodiments. Fig. 28 illustrates an example process according to an embodiment of the present disclosure. Fig. 29 illustrates an example process according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] In this disclosure, various embodiments are presented as examples of how the disclosed techniques can be implemented and / or how the disclosed techniques can be practiced in various environments and scenarios. It is obvious to a person skilled in the art that various modifications in form and detail can be made without altering the scope of protection. After reading the description, a person skilled in the art will understand how alternative embodiments can be implemented. The present embodiments may not be limited by any of the exemplary embodiments described. The embodiments of this disclosure are described with reference to the accompanying drawings.Limitations, features, and / or elements of the disclosed exemplary embodiments can be combined to create further embodiments within the scope of protection of the disclosure. All figures that highlight functionality and advantages serve only as examples. The disclosed architecture is sufficiently flexible and configurable so that it can also be used in ways other than those shown. For example, the actions listed in a flowchart can be rearranged or used only optionally in some embodiments.

[0030] Exemplary embodiments can be configured to function as needed. The disclosed mechanism can be executed when certain criteria are met, for example, in a station, access point, radio environment, network, a combination of the foregoing, and / or the like. Exemplary criteria may be based, at least in part, on configurations of wireless devices or network nodes, traffic load, initial system setup, packet sizes, traffic characteristics, a combination of the foregoing criteria, and / or the like. If one or more criteria are met, different exemplary embodiments can be applied. Therefore, it may be possible to implement exemplary embodiments that selectively implement disclosed protocols.

[0031] In this revelation, “a” and “an” and similar expressions are to be interpreted as “at least one” and “one or more.” Likewise, any term ending with the suffix “(s)” is to be interpreted as “at least one” and “one or more.” In this revelation, the term “may” is to be interpreted as “may, for example.” In other words, the term “may” indicates that the phrase following the term “may” is an example of one of many suitable possibilities that may or may not be used by one or more of the various embodiments. The terms “comprises” and “consists of,” as used herein, enumerate one or more components of the described element. The term “comprises” is interchangeable with “includes” and does not preclude the inclusion of unenumerated components in the described element.In contrast, "consists of" provides a complete list of one or more components of the described element. The term "based on," as used here, can be interpreted as "at least partially based on" and not, for example, as "exclusively based on." The term "and / or," as used here, represents any possible combination of the listed elements. For example, "A, B and / or C" could stand for A; B; C; A and B; A and C; B and C; or A, B, and C.

[0032] If A and B are sets and every element of A is an element of B, then A is called a subset of B. This patent specification considers only non-empty sets and subsets. Possible subsets of B = {STA1, STA2} are, for example: {STA1}, {STA2}, and {STA1, STA2}. The phrase "based on" (or equally "at least based on") indicates that the phrase following "based on" is an example of one of many suitable possibilities that may or may not be used for one or more of the various embodiments. The phrase "in response to" (or equally "at least in response to") indicates that the phrase following "in response to" is an example of one of many suitable possibilities that may or may not be used for one or more of the various embodiments.The phrase "depending on" (or equally "at least dependent on") indicates that the phrase following "depending on" is an example of one of many suitable options that may or may not be used for one or more of the various embodiments. The phrase "use / employ" (or equally "at least use / employ") indicates that the phrase following "use / employ" is an example of one of many suitable options that may or may not be used for one or more of the various embodiments.

[0033] The term "configured" can refer to the performance capabilities of a device, regardless of whether the device is in an operational or non-operational state. "Configured" can also refer to specific settings within a device that affect its operational characteristics, regardless of whether the device is in an operational or non-operational state. In other words, the hardware, software, firmware, registers, memory values, and / or the like within a device can be "configured," regardless of whether the device is in an operational or non-operational state, to impart specific characteristics to the device.Terms such as "a control message to be triggered in a device" can mean that a control message contains parameters that can be used to configure certain properties or to implement certain actions in the device, regardless of whether the device is in an operational or non-operational state.

[0034] In this disclosure, parameters (or equivalently fields or information elements: IEs) can comprise one or more information objects, and an information object can comprise one or more other objects. For example, if parameter (IE) N comprises parameter (IE) M, and parameter (IE) M comprises parameter (IE) K, and parameter (IE) K comprises parameter (information element) J, then, for example, NK comprises and N comprises J. If, in an exemplary embodiment, one or more messages / frames comprise a plurality of parameters, this means that a parameter from the plurality of parameters is included in at least one of the one or more messages / frames, but need not be included in every one of the one or more messages / frames.

[0035] Many of the presented features are described as optional by the use of "may" or by the use of parentheses. For the sake of brevity and readability, this disclosure does not explicitly address every single permutation that can be obtained by selecting from the set of optional features. This disclosure is to be interpreted as explicitly disclosing all such permutations. For example, a system described by three optional features can be embodied in seven ways: with only one of the three possible features, with any two of the three possible features, or with all three of the three possible features.

[0036] Many of the elements described in the disclosed embodiments can be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure can be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with a biological element), or a combination thereof, which may be behaviorally equivalent. For example, modules can be implemented as a software routine written in a computer language configured for execution by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab, or similar) or a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEW MathScript.It may be possible to implement modules using physical hardware containing separate or programmable analog, digital, and / or quantum hardware. Examples of programmable hardware include computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages ​​such as assembly language, C, C++, or similar. FPGAs, ASICs, and CPLDs are often programmed using hardware description languages ​​(HDLs) such as VHSIC or Verilog, which configure connections between lower-level internal hardware modules on a programmable device. These technologies are frequently used in combination to achieve the result of a functional module.

[0037] Fig. Figure 1 illustrates examples of wireless communication networks 100 in which embodiments of the present disclosure can be implemented.

[0038] As in Fig. As shown in Figure 1, the exemplary wireless communication networks 100 can include an infrastructure network 102 of the Institute of Electrical and Electronic Engineers (IEEE) 802.11 (WLAN). The WLAN infrastructure network 102 can include one or more Basic Service Sets (BSSs) 110 and 120, as well as a Distribution System (DS) 130.

[0039] BSS 110-1 and 110-2 each comprise a set consisting of an access point (AP or AP-STA) and at least one station (STA or non-AP-STA). For example, BSS 110-1 includes an AP 104-1 and an STA 106-1, and BSS 110-2 includes an AP 104-2, STA 106-2, and STA 106-3. The AP and the at least one STA in a BSS use an assignment procedure to communicate with each other.

[0040] The DS 130 can be configured to connect BSS 110-1 and BSS 110-2. Therefore, the DS 130 can enable an Extended Service Set (ESS) 150. Within the ESS 150, AP 104-1 and AP 104-2 are connected via the DS 130 and can have the same Service Set Identification (SSID).

[0041] The WLAN infrastructure network 102 can be linked to one or more external networks. For example, as shown in Fig. Figure 1 shows that the WLAN infrastructure network 102 is connected to another network 108 (e.g., 802.X) via a portal 140. The portal 140 can act as a bridge, connecting the DS 130 of the WLAN infrastructure network 102 to the other network 108.

[0042] The in Fig. The exemplary wireless communication networks illustrated in Figure 1 may further include one or more ad-hoc networks or independent BSSs (IBSSs). An ad-hoc network or IBSS is a network that includes a multitude of STAs located within communication range of each other. The multitude of STAs is configured to communicate with each other via direct peer-to-peer communication (i.e., not via an AP).

[0043] For example, in Fig. STA 106-4, STA 106-5, and STA 106-6 can be configured to form a first IBSS 112-1. Similarly, STA 106-7 and STA 106-8 can be configured to form a second IBSS 112-2. Because an IBSS does not include an access point, there is no centralized management unit. Instead, STAs within an IBSS are managed in a distributed manner. STAs that make up an IBSS can be fixed or mobile.

[0044] A system access control (STA), as the predefined functional medium, can include a Medium Access Control (MAC) layer that conforms to an IEEE 802.11 standard. A physical layer interface for a radio medium can be used between the access points (APs) and the non-AP stations (STAs). The STA can also be referred to by various other terms, including mobile terminal, wireless device, wireless transmit / receive unit (WTRU), user device (UE), mobile station (MS), mobile subscriber unit, or user. For example, the term "user" can be used to refer to an STA participating in an uplink transmission using Multi-User Multiple Input, Multiple Output (MU-MIMO) and / or an uplink transmission using Orthogonal Frequency Division Multiple Access (OFDMA).

[0045] A physical layer (PHY) protocol data unit (PPDU) can be a composite structure comprising a PHY preamble and a payload in the form of a PHY service data unit (PSDU). For example, the PSDU might include a PHY preamble and a PHY header and / or one or more MAC protocol data units (MPDUs). The information provided in the PHY preamble can be used by a receiving device to decode the subsequent data in the PSDU. In cases where PPDUs are transmitted over a bonded channel (a channel formed by channel bonding), the preamble fields can be duplicated and transmitted in each of the multiple component channels. The PHY preamble can include both a legacy portion (or "legacy preamble") and a non-legacy portion (or "non-legacy preamble").The legacy preamble can be used for purposes including packet detection, automatic gain control, and channel estimation. It can also generally be used to maintain compatibility with legacy devices. The format, encoding, and information in the non-legacy portion of the preamble are based on the specific IEEE 802.11 protocol intended for transmitting the payload.

[0046] A frequency band can include one or more sub-bands or frequency channels. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, 802.11ax, and / or 802.11be standard amendments can be transmitted over the 2.4 GHz, 5 GHz, and / or 6 GHz bands, with each band potentially subdivided into multiple 20 MHz channels. PPDUs can be transmitted over a physical channel with a minimum bandwidth of 20 MHz. Larger channels can be created by channel bonding. For example, PPDUs can be transmitted over physical channels with bandwidths of 40 MHz, 80 MHz, 160 MHz, or 1120 MHz by bonding multiple 20 MHz channels.

[0047] Fig. Figure 2 is a block diagram 200 illustrating example implementations of an STA 210 and an AP 260. As shown in Fig. As shown in Figure 2, STA 210 can include at least one processor 220, one memory 230, and at least one transceiver 240. AP 260 can include at least one processor 270, one memory 280, and at least one transceiver 290. The processor 220 / 270 can be operationally connected to the transceiver 240 / 290.

[0048] The 240 / 290 transceiver can be configured to transmit / receive radio signals. In one embodiment, the 240 / 290 transceiver can implement a PHY layer of the corresponding device (STA 210 or AP 260).

[0049] In one embodiment, the STA 210 and / or AP 260 can be a multi-link device (MLD), i.e., a device that can operate over multiple links, as defined in the IEEE 802.11be standard amendment. Therefore, the STA 210 and / or AP 260 can each have multiple PHY layers. These multiple PHY layers can be implemented using one or more 240 / 290 transceivers.

[0050] The 220 / 270 processor can implement functions of the PHY layer, the MAC layer and / or the Logical Link Control layer (LLC layer) of the corresponding device (STA 210 or AP 260).

[0051] Processor 220 / 270 and / or transceiver 240 / 290 may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and / or data processors. Memory 230 / 280 may include read-only memory (ROM), random-access memory (RAM), flash memory, a memory card, a storage medium, and / or another storage unit.

[0052] When the embodiments are executed by software, the techniques (or methods) described herein can be implemented using modules (e.g., processes, functions, etc.) that perform the functions described herein. The modules can be stored in memory 230 / 280 and executed by processor 220 / 270. Memory 230 / 280 can be implemented (or located) inside or outside of processor 220 / 270. Memory 230 / 280 can be operationally connected to processor 220 / 270 by various means known in the prior art.

[0053] Fig. Figure 3 illustrates an example format for a MAC frame 300. In operation, a STA can create a subset of MAC frames for transmission and, after validation, decode a subset of the received MAC frames. The specific subsets of frames that an STA can create and / or decode can be determined by the functions supported by the STA. An STA can validate a received MAC frame using the frame check sequence (FCS) contained in the frame and interpret certain fields from the MAC headers of all frames.

[0054] As in Fig. As shown in Figure 3, the MAC frame 300 includes a MAC header, a variable-length frame body, and a block check string (FCS).

[0055] The MAC header includes a "Frame Control" field, an optional "Duration / ID" field (not in PS poll frames), address fields, an optional "Sequence Control" field, an optional "QoS Control" field (only in QoS data frames), and an optional "High Throughput Control" field (HT Control field) (only in +HTC frames).

[0056] The "Frame Control" field includes the following subfields: Protocol Version, Type, Subtype, To DS, From DS, Additional Fragments, Retry, Power Management, Additional Data, Protected Frame, and High Throughput Control (+HTC).

[0057] The "Protocol Version" subfield remains unchanged in size and placement across all revisions of the IEEE 802.11 standard. The value of the "Protocol Version" subfield is 0 for MAC frames.

[0058] The subfields "Type" and "Subtype" together identify the function of the MAC frame. There are three frame types: control, data, and management. Each frame type has several defined subtypes. Bits within the "Subtype" subfield are used to indicate a specific modification of the base data frame (subtype 0). For example, in data frames, the most significant bit (MSB) of the "Subtype" subfield, bit 7 (B7) of the "Frame Control" field, is defined as the "QoS" subfield. When the "QoS" subfield is set to 1, it indicates a data frame of subtype "QoS," meaning a data frame that contains a "QoS Control" field in its MAC header. The second MSB of the "Subtype" field, bit 6 (B6) of the "Frame Control" field, when set to 1 in data subtypes, indicates a data frame that does not contain a "Frame Body" field.

[0059] The subfield "To DS" indicates whether a data frame is intended for the DS. The subfield "From DS" indicates whether a data frame originates from the DS.

[0060] The "Additional Fragments" subfield is set to 1 in all data or management frames that are followed by another fragment of the MAC Service Data Unit (MSDU) or MAC Management Protocol Data Unit (MMPDU) transmitted by the MAC frame. In all other frames where the "Additional Fragments" subfield is present, it is set to 0.

[0061] The "Repeat" subfield is set to 1 in every data or management frame that is a retransmission of a previous frame. In all other frames where the "Repeat" subfield exists, it is set to 0. A receiving STA uses this information to help eliminate duplicate frames. These rules do not apply to frames sent by an STA under a block agreement.

[0062] The "Energy Management" subfield is used to specify the energy management mode of an STA.

[0063] The "Additional Data" subfield indicates to a data center (STA) in power-saving mode (PS mode) that bufferable units (BUs) for this STA are buffered at the access point (AP). The "Additional Data" subfield is valid in individually addressed data or management frames that are transferred from an AP in PS mode to an STA. The "Additional Data" subfield is set to 1 to indicate that at least one additional buffered BU is available for the STA.

[0064] The "Protected Frame" subfield is set to 1 if the frame body field contains information that has been processed by a cryptographic encapsulation algorithm.

[0065] The subfield “+HTC” indicates that MAC frame 300 contains an “HT Control” field. A frame containing the “HT Control” field is called a +HTC frame. A control wrapper frame is a +HTC frame.

[0066] The "Duration / ID" field of the MAC header contains different information depending on the frame type and subtype, as well as the QoS capabilities of the sending STA. For example, in control frames of the "Power Save Poll" (PS Poll) subtype, the "Duration / ID" field contains the association identifier (AID) of the STA that transmitted the frame in the 14 least significant bits (LSB), and the two most significant bits (MSB) are both set to 1. In other frames sent by STAs, the "Duration / ID" field contains a duration value (in microseconds) that a receiver uses to update a network allocation vector (NAV). The NAV is a counter that indicates to an STA the period of time during which it must refrain from accessing the shared medium.

[0067] The MAC frame 300 format can contain up to four address fields. These fields are used to specify the Basic Service Set Identifier (BSSID), the source address (SA), the destination address (DA), the sending address (TA), and the receiving address (RA). Some frames may lack certain address fields. The use of specific address fields can be indicated by the relative position of the address field (1-4) within the MAC header, regardless of the address type present in that field. Specifically, the "Address 1" field always identifies the intended recipient(s) of the frame, and the "Address 2" field, if present, always identifies the sender of the frame.

[0068] The "Sequence Control" field includes two subfields: the "Sequence Number" subfield and the "Fragment Number" subfield. In data frames, the "Sequence Number" subfield specifies the sequence number of the MSDU (unless it is an aggregated MSDU (A-MSDU)) or A-MSDU. In management frames, the "Sequence Number" subfield specifies the sequence number of the frame. The "Fragment Number" subfield specifies the number of each fragment of an MSDU or MMPDU. The fragment number is set to 0 in the first or only fragment of an MSDU or MMPDU and incremented by one for each subsequent fragment of that MSDU or MMPDU. The fragment number is set to 0 in a MAC protocol data unit (MPDU) containing an A-MSDU or in an MPDU containing a non-fragmented MSDU or MMPDU. The fragment number remains constant across all retransmissions of the fragment.

[0069] The "QoS Control" field identifies the traffic category (TC) or traffic stream (TS) to which MAC frame 300 belongs. The "QoS Control" field can also specify various other QoS-related, A-MSDU-related, and mesh-related information about the frame. This information can vary depending on the frame type, frame subtype, and type of transmitting STA. The "QoS Control" field is present in all data frames where the "QoS" subfield of the "Subtype" subfield is equal to 1.

[0070] The "HT Control" field is present in QoS data frames, QoS null frames, and management frames, as determined by the "+HTC" subfield of the "Frame Control" field. The control frame subtype for which the "HT Control" field exists is the control wrapper frame. A control frame described as +HTC (for example, a Send Request (RTS)+HTC, Send Release (CTS)+HTC, Block Acknowledge (BlockAck)+HTC, or Block AckReq (BlockAckReq)+HTC frame) implies the use of the control wrapper frame to transmit that control frame.

[0071] The "Frame-Body" field is a variable-length field containing specific information about individual frame types and subtypes. It can include one or more MSDUs or MMPDUs. The minimum length of the frame body is 0 octets.

[0072] The "FCS" field contains a 32-bit CRC (Cyclic Redundancy Check) code. The value of the "FCS" field is calculated across all fields of the MAC header and the "Frame Body" field.

[0073] Fig. Figure 4 illustrates an example management frame 400 that can be used as an action frame. For instance, management frame 400 includes a MAC header, a variable-length frame body, and a block check string (FCS). The MAC header includes a "Frame Control" field, a "Duration / ID" field, an "Address 1" field, an "Address 2" field, an "Address 3" field, a "Sequence Control" field, and an optional "HT Control" field. The presence of the "HT Control" field is determined by setting a subfield "+HTC" of the "Frame Control" field.

[0074] As in Fig. As shown in Figure 4, when used as an action frame, the frame body of the management frame contains an "Action" field, vendor-specific elements, a Management Message Integrity Code (MME) element, a Message Integrity Code (MIC), and an authenticated mesh peering exchange element.

[0075] The "Action" field includes a "Category" field and an "Action Details" field. The "Action" field provides a mechanism for defining advanced administrative actions. The "Category" field specifies a category for the action frame. The "Action Details" field contains the details of the action requested by the action frame. For example, the action frame might be a public action frame. As in Fig. As shown in Figure 4, the "Action Details" field in the public action frame format includes a "Public Action" field in the octet immediately after the "Category" field, followed by a variable-length "Public Action Details" field.

[0076] Optionally, one or more vendor-specific elements may be present. These elements are missing if the "Category" subfield of the "Action" field is vendor-specific.

[0077] The MME is present if the management frame's protection is negotiated, the frame is a group-addressed robust action frame, and (MBSS only) the action frame's category does not support group-addressed privacy, as indicated by the category values; otherwise, it is not present.

[0078] The MIC element is present in a self-protected action frame if a common pairwise master key (PMK) exists between the sender and the receiver of that frame; otherwise, it is not present.

[0079] The authenticated mesh peering exchange element is present in a self-protected action frame if a common PMK exists between the sender and receiver of that frame; otherwise, it is not present.

[0080] Fig. Figure 5 illustrates a sample format for a Trigger Frame 500. A Trigger Frame 500 can be used by an AP to allocate and request resources for one or more TB-PPDU transfers from one or more STAs. The Trigger Frame 500 can also contain other information that a responding STA needs to transfer a TB-PPDU to the AP.

[0081] As in Fig. As shown in Figure 5, the trigger frame 500 includes a "Frame Control" field, a "Duration" field, a "Receiver Address" (RA) field, a "Sender Address" (TA) field, a "General Information" field, a "User Information List" field, a "Padding" field, and an "FCS" field.

[0082] The "Frame Control" field includes the following subfields: Protocol Version, Type, Subtype, To DS, From DS, Other Fragments, Retry, Power Management, Other Data, Protected Frame and +HTC.

[0083] The "Duration" field displays different content depending on the frame type and subtype, as well as the QoS capabilities of the sending STA. For example, in control frames of the "Power Save Poll" (PS-Poll) subtype, the "Duration" field contains an allocation identifier (AID) of the STA that transmitted the frame in the 14 least significant bits (LSB), and the two most significant bits (MSB) are both set to 1. In other frames sent by STAs, the "Duration" field contains a duration value (in microseconds) that is used by a receiver to update a network allocation vector (NAV).

[0084] The "RA" field is the address of the STA that will receive the incoming transmission from the sending station. The "TA" field is the address of the STA that will transmit trigger frame 500 if trigger frame 500 is addressed to STAs belonging to a single BSS. The "TA" field is the transmitted BSSID if trigger frame 500 is addressed to STAs of at least two different BSSs in the set with multiple BSSIDs.

[0085] The "General Information" field specifies the trigger frame type of trigger frame 500, the transmit power of trigger frame 500 in dBm, and several key parameters of a TB-PPDU transmitted by a STA in response to trigger frame 500. The trigger frame type of a trigger frame used by an AP to receive QoS data using UL-MU operation is referred to as the basic trigger frame. A non-EHT, non-AP HE STA interprets the "General Information" field as an HE variant. A non-AP EHT STA interprets the "General Information" field as an HE variant if B54 and B55 in the "General Information" field are equal to 1; otherwise, it interprets the "General Information" field as an EHT variant.The "General Information" field of the HE variant and the "General Information" field of the EHT variant use the same coding procedure for the subfields "Trigger Type", "UL Length", "Additional TF", "CS Required", "LDPC Additional Symbol Segment", "AP-TX Power", "Pre-FEC Padding Factor", "PE Uniqueness" and "Trigger-Dependent General Information".

[0086] The "User Information List" field contains zero or more "User Information" fields. There are three variants for the "User Information" field: the "Special User Information" field, the "EHT Variant User Information" field, and the "HE Variant User Information" field.

[0087] The "Special User Information" field is a user information field that does not contain user-specific information, but rather extended general information not provided in the "General Information" field. If the "Special User Information" field is included in the trigger frame, the "Special User Information Field Flag" subfield of the "General Information" field in the EHT variant is set to 0; otherwise, it is set to 1. The "Special User Information" field is identified by an AID12 value of 2007 and is optionally present in a trigger frame generated by an EHT AP. If present, the "Special User Information" field is located immediately after the "General Information" field in the trigger frame and contains information for the "U-SIG" field of a requested EHT TB-PPDU.The "PHY Version Identifier" subfield specifies the PHY version of the requested TB-PPDU that is not an HE-TB-PPDU. The "PHY Version Identifier" subfield is set to 0 for EHT. Other values ​​from 1 to 7 are reserved. The "UL Bandwidth Extension (UL-BW Extension)" subfield, together with the "UL-BW" subfield in the "General Information" field, specifies the bandwidth of the requested TB-PPDU from the addressed EHT-STA (i.e., the bandwidth in the "U-SIG" field of the EHT-TB-PPDU). The "EHT Spatial Reuse n" subfield contains the values ​​to be included in the corresponding "Spatial Reuse n" subfield in the "U-SIG" field of the EHT-TB-PPDU. The subfield “Ignore and validate U-SIG” contains the values ​​to be included in the “Ignore” and “Validate” subfields of the “U-SIG” field of the requested EHT-TB-PPDU.The presence and length of the subfield "Trigger-dependent user information" in the field "Special user information" depend on the variant of the trigger frame.

[0088] The "EHT Variant User Information" field contains one "User Information" field per STA, addressed in trigger frame 500. The "User Information per STA" field includes, among other things, an "AID12" subfield, a "RU Assignment" subfield, a "UL-FEC Encoding Type" subfield, a "UL-EHT-MCS" subfield, a "Reserved" subfield, a "Spatial Stream (SS) Assignment / RA-RU Information" subfield, a "UL Destination Receive Power" subfield, and a "Power Saving (PS) 160" subfield, to be used by an STA in a TB-PPDU transmitted in response to trigger frame 500, as well as a "Trigger-Dependent User Information" subfield.The subfield "RU Assignment" in an "EHT Variant User Information" field in a trigger frame that is not an MU-RTS trigger frame, together with the subfield "UL-BW" in the "General Information" field, the subfield "UL-BW Extension" in the "Special User Information" field, and the subfield "PS160" in the "EHT Variant User Information" field, identifies the size and location of the RU or MRU. The values ​​of subfield "PS160" and B0 of subfield "RU Assignment" specify the 80 MHz frequency sub-block in which the RU or MRU is located for 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 484-tone RU, 996-tone RU, 52+26-tone RU, and 106+26-tone RU. The values ​​of subfield "PS160" specify the 160 MHz segment in which the RU or MRU is located for 2□996-tone RU, 996+484-tone MRU, and 996+484+242-tone MRU. The subfield “UL-FEC Encoding Type” of the “User Information” field specifies the encoding type of the requested EHT-TB-PPDU.The "UL-FEC Encoding Type" subfield is set to 0 to indicate BCC and to 1 to indicate LDPC. The "UL-EHT-MCS" subfield of the "User Information" field specifies the EHT-MCS of the requested EHT-TB-PPDU. The "SS Assignment" subfield of the "EHT Variant User Information" field specifies the spatial streams of the requested EHT-TB-PPDU. The "UL Target Receive Power" subfield specifies the expected received signal power, measured at the AP's antenna port and averaged across the antennas for the EHT portion of the EHT-TB-PPDU being transmitted on the assigned RU. The "Trigger-Dependent User Information" subfield can be used by an AP to specify a preferred access category (AC) per STA. The preferred AC determines the minimum priority AC traffic that can be sent by a participating STA.The AP determines the list of participating STAs along with BW, MCS, RU allocation, SS allocation, Tx power, preferred AC, and maximum TB-PPDU duration for each participating STA. The subfield "RA-RU Information" is reserved within the "EHT Variant User Information" field.

[0089] The padding field is optionally present in trigger frame 400 to extend the frame length and give the receiving STAs sufficient time to prepare a response for transmitting a SIFS after receiving the frame. If present, the padding field is at least two octets long, and all digits are set to 1.

[0090] The "FCS" field is used by a STA to validate a received frame and to interpret certain fields from the MAC headers of a frame.

[0091] Fig. Figure 6 illustrates an example data frame 600 that can be used as a QoS null frame. A QoS null frame refers to a QoS data frame with an empty frame body. The QoS null frame includes a "QoS Control" field and an optional "HT Control" field, which can contain a "Buffer State Report (BSR) Control" subfield. A QoS null frame that specifies buffer state information can be transmitted from a STA to an AP.

[0092] The "QoS control" field can include a subfield "Traffic Identifier (TID)", a subfield "Ack Confirmation Policy Indicator" and a subfield "Queue Size" (or a subfield "Requested Transfer Opportunity Duration" (TXOP)).

[0093] The "TID" subfield identifies the TC or TS of the traffic for which a TXOP is requested, by setting the requested TXOP duration or the "Queue Size" subfield. The encoding of the "TID" subfield depends on the access policy (e.g., a allowed value of 0 to 7 for the Enhanced Distributed Channel Access (EDCA) policy to identify the user priority for the TC or TS).

[0094] The subfield “Ack Policy Indicator” identifies, along with other information, the Ack policy that was followed when submitting the MPDU (e.g. normal Ack, implicit block Ack request, no Ack, block Ack, etc.).

[0095] The "Queue Size" subfield is an 8-bit field that specifies the amount of buffered traffic for a particular TC or TS at the STA for transmission to the AP, which is identified by the receiver address of the frame containing the subfield. The "Queue Size" subfield is present in QoS null frames sent by an STA when bit 4 of the "QoS Control" field is set to 1. The AP can use the information contained in the "Queue Size" subfield to determine the TXOP duration allocated to the STA or to determine the uplink resources (UL resources) allocated to the STA.

[0096] In a frame sent to or from a non-high-efficiency (non-HE) STA, the following rules may apply to the queue size value: The queue size value is the approximate total size, rounded up to the nearest multiple of 256 octets and expressed in units of 256 octets, of all MSDUs and A-MSDUs buffered at the STA (excluding the MSDU or A-MSDU contained in the current QoS data frame) in the delivery queue used for MSDUs and A-MSDUs with TID values ​​that match the value specified in the "TID" subfield of the "QoS Control" field.

[0097] A queue size value of 0 is used solely to indicate the absence of any buffered traffic in the queue used for the specified TID.

[0098] For all sizes above 64,768 octets, a queue size value of 254 is used.

[0099] A queue size value of 255 is used to indicate an unspecified or unknown size.

[0100] In a frame sent from an HE-STA to an HE-AP, the following rules can apply to the queue size value.

[0101] The queue size value QS is the approximate total size in octets of all MSDUs and A-MSDUs buffered at the STA (including MSDUs or A-MSDUs contained in the same PSDU as the frame containing the "Queue Size" subfield) that are in the delivery queue used for MSDUs and A-MSDUs with TID values ​​that match the value specified in the "TID" subfield of the "QoS Control" field.

[0102] The subfield "Queue Size" includes a subfield "Scaling Factor" in bits B14-B15 of the "QoS Control" field and an unscaled value, UV, in bits B8-B13 of the "QoS Control" field. The subfield "Scaling Factor" specifies the scaling factor SF.

[0103] A STA receives the queue size QS from a received field “QoS control”, which contains a scaling factor SF and an unscaled value UV, as follows: QS = 16×UV if SF equals 0; 1024 + 256×UV if SF equals 1; 17 408+2048×UV, if SF equals 2; 148 480+32 768×UV, if SF equals 3 and UV is less than 62; >2 147 328, if SF equals 3 and UV equals 62;

[0104] Not specified or Unknown if SF equals 3 and UV equals 63.

[0105] The "Requested TXOP Duration" subfield, which can be included in place of the "Queue Size" subfield, specifies the duration, in units of 32 microseconds (µs), that the sending STA requires for its next TXOP for the specified TID. The "Requested TXOP Duration" subfield is set to 0 to indicate that no TXOP is requested for the specified TID during the current service period (SP). The "Requested TXOP Duration" subfield is set to a non-zero value to specify a requested TXOP duration in the range of 32 µs to 8160 µs, in increments of 32 µs.

[0106] The field "HT Control" can include a subfield "Aggregated Control" (A Control). The subfield "A Control" can include a subfield "Control List", which in turn contains one or more subfields "Control".

[0107] The subfield "Control" can be a subfield "BSR Control" which can contain buffer status information used for UL-MU operation. The "BSR Control" subfield can be formed from a subfield "ACI Bitmap" (Access Category Index Bitmap), a subfield "Delta TID", a subfield "ACI High", a subfield "Scaling Factor", a subfield "Queue Size High", and a subfield "Queue Sizes All" of the field "HT Control".

[0108] The "ACI-Bitmap" subfield specifies the access categories for which the buffer status is reported (e.g., B0: Best Effort (AC_BE), B1: Background (AC_BK), B2: Video (AC_VI), B3: Speech (AC_VO), etc.). Each bit of the "ACI-Bitmap" subfield is set to 1 to indicate that the buffer status of the corresponding AC is included in the "Queue Size All" subfield, and is otherwise set to 0, except that if the "ACI-Bitmap" subfield is 0 and the "Delta-TID" subfield is 3, then the buffer status of all 8 TIDs is included.

[0109] The subfield “Delta-TID”, together with the values ​​of the subfield “ACI-Bitmap”, specifies the number of TIDs for which the STA reports the buffer status.

[0110] The subfield "ACI high" specifies the ACI of the AC for which the BSR is specified in the subfield "Queue size high". The mapping of ACI to AC is defined as mapping ACI value 0 to AC_BE, ACI value 1 to AC_BK, ACI value 2 to AC_VI, and ACI value 3 to AC_VO.

[0111] The subfield "Scaling factor" specifies the unit SF in octets of the subfields "Queue size high" and "Queue size all".

[0112] The subfield "Queue size high" specifies the amount of buffered traffic in units of SF octets for the AC identified by the subfield "ACI high", which is destined for the STA identified by the receiver address of the frame containing the subfield "BSR control".

[0113] The subfield "Queue size all" specifies the amount of buffered traffic in units of SF octets for all ACs identified by the subfield "ACI bitmap", which is intended for the STA identified by the receiver address of the frame containing the subfield "BSR control".

[0114] The queue size values ​​in the subfields "Queue size high" and "Queue size all" are the total sizes, rounded up to the nearest multiple of SF octets, of all MSDUs and A-MSDUs buffered at the STA (including the MSDUs or A-MSDUs contained in the same PSDU as the frame containing the "BSR control" subfield) in delivery queues used for MSDUs and A-MSDUs associated with AC(s) specified in the subfields "ACI high" and "ACI bitmap".

[0115] A queue size value of 254 in the "Queue Size High" and "Queue Size All" subfields indicates that the amount of buffered traffic is greater than 254 × SF octets. A queue size value of 255 in both the "Queue Size High" and "Queue Size All" subfields indicates that the amount of buffered traffic is of an unspecified or unknown size. The queue size value of QoS data frames containing fragments can remain constant even if the amount of traffic in the queue changes as successive fragments are transmitted.

[0116] The MAC service allows peer entities to exchange MSDUs. To support this service, a local MAC uses the underlying service at the PHY layer to transport the MSDUs to a peer MAC entity. This asynchronous MSDU transport is connectionless.

[0117] Fig. Figure 7 illustrates an example format for a PPDU. As shown, the PPDU can include a PHY preamble, a PHY header, a PSDU, and tail and padding bits.

[0118] The PSDU can contain one or more MPDUs, such as a QoS data frame, an MMPDU, a MAC control frame, or a QoS null frame. In the case of an MPDU containing a QoS data frame, the MPDU's frame body can include an MSDU or an A-MSDU.

[0119] By default, MSDU transport follows the best-effort principle. This means there is no guarantee that a transmitted MSDU will be successfully delivered. However, the QoS function uses a traffic identifier (TID) to specify differentiated services based on MSDUs.

[0120] A STA can differentiate MSDU delivery based on the defined traffic category (TC) or traffic stream (TS) of individual MSDUs. The MAC sublayer entities determine a user priority (UP) for an MSDU based on a TID value provided with the MSDU. The QoS function supports eight UP values. The UP values ​​range from 0 to 7, forming an ordered sequence of priorities, with 1 being the lowest value, 7 the highest value, and 0 being between 2 and 3.

[0121] An MSDU with a specific UP belongs to a traffic category with that UP. The UP can be directly provided as a UP parameter for each MSDU at the Medium Access Control Service Access Point (MAC-SAP). An A-MPDU can include MPDUs with different TID values.

[0122] A STA can deliver Buffer Status Reports (BSRs) to assist an AP in allocating UL-MU resources. The STA can deliver BSRs either implicitly in the QoS Control field or the BSR Control subfield of any frame transmitted to the AP (unsolicited BSR), or explicitly in a frame sent to the AP in response to a BSRP trigger frame (solicited BSR).

[0123] The buffer status reported in the "QoS Control" field includes a queue size value for a specific TID. The buffer status reported in the "BSR Control" field includes an ACI bitmap, a delta TID, a high-priority AC, and two queue sizes.

[0124] A STA can report the buffer status of the transmitted QoS null frames and QoS data frames to the AP in the "QoS control" field and in the "BSR control" subfield (if available) of the transmitted QoS null frames, QoS data frames and management frames as defined below.

[0125] The STA can report the queue size for a specific TID in the "Queue Sizes" subfield of the "QoS Control" field of transmitted QoS data frames or QoS null frames. The STA can set the "Queue Size" subfield to 255 to indicate an unknown / unspecified queue size for that TID. The STA can combine multiple QoS data frames or QoS null frames in an A-MPDU to report the queue size for different TIDs.

[0126] The STA can report the buffer status in the "BSR control" subfield of the transmitted frames if the AP has indicated its support for receiving the "BSR control" subfield.

[0127] A high-efficiency (HE) STA can report the queue size for a preferred AC, specified by the "High ACI" subfield, in the "High Queue Size" subfield of the "BSR Control" subfield. The STA can set the "High Queue Size" subfield to 255 to indicate an unknown / unspecified queue size for that AC.

[0128] A HE-STA can report the queue size for ACs, specified by the "ACI Bitmap" subfield in the "Queue Size All" subfield of the "BSR Control" subfield. The STA can set the "Queue Size" subfield to 255 to indicate an unknown / unspecified BSR for these ACs.

[0129] Fig. Figure 8 illustrates an exemplary reference model for a multi-link device (MLD). An MLD is a unit capable of managing communication across multiple links. The MLD can be a logical unit and have more than one connected station (STA). An MLD can be an access-point MLD (AP-MLD), where an STA connected to the MLD is an AP-STA (or an AP). An MLD can also be a non-access-point MLD (non-AP-MLD), where an STA connected to the MLD is a non-AP-STA (or an STA).

[0130] Communication across different frequency bands / channels may or may not occur simultaneously, depending on the capabilities of the communicating AP-MLD and the non-AP-MLD.

[0131] As in Fig. As shown in Figure 8, an MLD can have a single MAC service access point (MAC-SAP) to the LLC layer, which includes a MAC data service. The MLD can support multiple MAC sublayers coordinated by a sublayer management entity (SME). Each AP-STA (or non-AP-STA) connected to an AP-MLD (or non-AP-MLD) has a different MAC address within the MLD.

[0132] The SME is responsible for coordinating the MAC sublayer management units (MLMEs) of the MLD's affiliated STAs to maintain a single Robust Security Network Association (RSNA) robust key management unit and a single IEEE 802.1X authenticator or supplicant for multi-link operation (MLO).

[0133] Using multiple link operation (MLO) procedures, a pair of MLDs can discover, synchronize, (de)authenticate, (re)assign, disconnect, and manage resources on all shared bands or channels supported by both MLDs. The authenticator and MAC-SAP of an AP-MLD can be identified by the same AP-MLD MAC address. The supplicant and MAC-SAP of a non-AP-MLD can be identified by the same non-AP-MLD MAC address.

[0134] Fig. Figure 9 illustrates an example of an AP-MLD and an associated non-AP-MLD.

[0135] As shown, the AP-MLD has two connected APs (AP1 and AP2), and the non-AP-MLD has two connected STAs (STA1 and STA2). The AP-MLD and the non-AP-MLD can be communicatively coupled via two connections (Connection 1 and Connection 2). Connection 1 is established between AP1 and STA1, and Connection 2 is established between AP2 and STA2.

[0136] Generally, the MAC addresses of an MLD and its associated STAs differ from each other. As in Fig. As shown in Figure 9, for example, the AP-MLD can have the MAC address M, AP 1 can have the MAC address w, and AP2 can have a MAC address x. Similarly, the non-AP-MLD can have the MAC address P, STA 1 can have the MAC address y, and STA2 can have the MAC address z.

[0137] As in Fig. As shown in Figure 9, the MAC sublayer of each MLD can be further subdivided into an upper MAC sublayer and a lower MAC sublayer. The upper MAC sublayer (MLD) of the MLD performs functions common to all connections. The lower MAC sublayer of the MLD performs functions local to each connection. Some of these functions require joint processing by both the upper and lower MAC sublayers of the MLD.

[0138] The functions of the upper MAC sublayer of the MLD can include: Authentication, mapping and remapping (between an AP-MLD and a non-AP-MLD); Security association (e.g. Pairwise Master Key Security Association (PMKSA), Pairwise Transient Key Security Association (PTKSA)) and distribution of Group Temporary Key (GTK) / Integrity GTK (IGTK) / Beacon IGTK (BIGTK); Assignment of sequence numbers (SN) / packet numbers (PN) for frames to be encrypted with Pairwise Transient Key (PTK) for unicast frames; Encryption / decryption with PTK for unicast frames; Selection of the lower MAC sublayer of the MLD for transmission (TID-to-connection mapping); Reordering the packages to ensure sequential delivery for each block ack session; Block ack scoreboarding for individually addressed frames (in cooperation with the lower MAC sublayer of the MLD); optionally, the upper MAC sublayer of the MLD passes the block ack record on one connection to the lower MAC sublayer of the MLD on other connections; and Exchange / provision of administrative information at the MLD level via the lower MAC sublayer of the MLD.

[0139] The functions of the lower MAC sublayer of the MLD can include: Maintenance of connection-specific GTK / IGTK / BIGTK (between an AP connected to the AP-MLD and an STA connected to the non-AP-MLD); Connection-specific encryption / decryption / integrity protection and PN assignment using GTK / IGTK / BIGTK (between an AP connected to the AP-MLD and an STA connected to the non-AP-MLD); Connection-specific exchange / connection-specific provision of administrative information (e.g., beacon); Connection-specific exchange / connection-specific provision of control information (e.g. RTS / CTS, acknowledgments, etc.); Energy saving state and mode; MAC address filtering for frame reception; and Block ack scoreboarding for individually addressed frames (in cooperation with the upper MAC sublayer of the MLD); optionally, the lower MAC sublayer of the MLD receives the block ack data set on the other links from the upper MAC sublayer of the MLD.

[0140] Establishing a multi-connection between a non-AP MLD and an AP MLD can involve exchanging reassignment request / response frames. This exchange of reassignment request / response frames for a multi-connection setup can include both frames containing a basic multi-connection element.

[0141] In the (re)assignment request frame, the non-AP MLD specifies the connections requested for (re)establishment, as well as the capabilities and operating parameters of the requested connections. The non-AP MLD can request the (re)establishment of connections with a subset of the APs associated with the AP MLD. The connections requested for (re)establishment, as well as the capabilities and operating parameters of the requested connections, are independent of existing establishment connections with an associated AP MLD and the capabilities and operating parameters of those establishment connections.

[0142] In the (re)assignment response frame, the AP-MLD can specify the requested connections that are accepted and those that are rejected for (re)assignment, as well as the capabilities and operating parameters of the requested connections. The AP-MLD may accept a subset of the connections requested for (re)assignment. The (re)assignment response frame is sent to the non-AP-STA connected to the non-AP-MLD that sent the (re)assignment response frame.

[0143] An MLD that requests or accepts the (re)establishment of multiple connections for any two connections ensures that each connection is on a different, non-overlapping channel. After successful (re)establishment of a multiple connection between a non-AP MLD and an AP MLD, the non-AP MLD and the AP MLD establish connections for multiple connection operation, and the non-AP MLD is (re)assigned to the AP MLD. For each established connection, the corresponding non-AP STA associated with the non-AP MLD is in the same connection state as the non-AP MLD and is connected to a corresponding AP associated with the AP MLD. For each established connection, functions between a non-AP STA and its associated AP are enabled, unless the functions have been extended to the MLD level or otherwise specified.

[0144] Fig. Figure 10 illustrates an example of a multi-link setup between an AP-MLD and a non-AP-MLD. As shown, the AP-MLD has three connected APs: AP 1 operates in the 2.4 GHz band, AP 2 operates in the 5 GHz band, and AP 3 operates in the 6 GHz band. The non-AP-MLD has three connected STAs: Non-AP-STA 1, operating in the 2.4 GHz band, Non-AP-STA 2, operating in the 5 GHz band, and Non-AP-STA 3, operating in the 6 GHz band.

[0145] The non-AP MLD can initiate multi-connection setup by sending an MLD request frame to AP 1, which is connected to the AP MLD. In the MLD request frame, the Sender Address (TA) field is set to the MAC address of non-AP STA 1, and the Receiver Address (RA) field is set to the MAC address of AP 1. The MLD request frame includes a basic multi-connection element that specifies the MLD MAC address of the non-AP MLD and complete information about non-AP STA 1, non-AP STA 2, and non-AP STA 3. The MLD request frame can request the establishment of three connections between the non-AP MLD and the AP MLD (one connection between AP 1 and non-AP STA 1, one connection between AP 2 and non-AP STA 2, and one connection between AP 3 and non-AP STA 3).

[0146] The AP-MLD can respond to the requested multi-connection setup by having the AP send an Mapping Request Frame to the non-AP-STA 1 connected to the non-AP-MLD. In the Mapping Request Frame, the "TA" field is set to the MAC address of AP 1 and the "RA" field is set to the MAC address of non-AP-STA 1. The Mapping Request Frame contains a basic multi-connection element that specifies the MLD MAC address of the AP-MLD and complete information about AP 1, AP 2, and AP 3. The Mapping Request Frame signals the successful multi-connection setup by establishing three connections between the non-AP-MLD and the AP-MLD (connection 1 between AP 1 and non-AP-STA 1, connection 2 between AP 2 and non-AP-STA 2, and connection 3 between AP 3 and non-AP-STA 3).

[0147] By default, all TIDs on the non-AP MLD are mapped to all facility connections for both uplink and downlink. The TID-to-connection mapping mechanism allows an AP MLD and a non-AP MLD that have performed or are performing a multi-connection setup to specify how UL and DL QoS traffic corresponding to different TIDs (e.g., between 0 and 7) can be allocated to the facility connections. With a negotiated TID-to-connection mapping, a TID can be assigned to a connection set that represents a subset of facility connections, ranging from a single facility connection to all facility connections.

[0148] A facility connection is defined as enabled for a non-AP MLD if at least one TID is assigned to that connection in either DL or UL, and as disabled if no TIDs are assigned to that connection in either DL or UL. At any given time, a TID is always assigned to at least one facility connection in both DL and UL. This means that a change to the TID-to-connection mapping can only be valid and successful if it does not result in a TID having an assigned connection set consisting of zero facility connections.

[0149] By default, all facility connections are enabled. If a connection is enabled for a non-AP MLD, it can be used to exchange individually addressed frames, depending on the power state of the non-AP STA operating on that connection. Only MSDUs or A-MSDUs with TIDs assigned to a connection may be transmitted on this connection, in the direction (DL / UL) corresponding to the TID-to-connection mapping. Individually addressed management and control frames can be sent in both DL and UL directions over any enabled connection between a connected STA of the non-AP MLD and a corresponding AP of the AP MLD.

[0150] If a connection is disabled for a non-AP-MLD, the connection must not be used for exchanging individually addressed frames between a connected STA of the non-AP-MLD and a corresponding AP of the AP-MLD.

[0151] If a TID in UL is associated with a set of enabled connections for a non-AP MLD, the non-AP MLD can use any connection within that set of enabled connections to transmit individually addressed MSDUs or A-MSDUs corresponding to that TID.

[0152] When a TID in DL is associated with a set of enabled connections for a non-AP MLD, the non-AP MLD can retrieve individually addressed BUs on each connection in the set of enabled connections. These BUs are buffered in the AP MLD and are MSDUs or A-MSDUs corresponding to the TID. Conversely, the AP MLD can use each connection within the set of enabled connections to transmit individually addressed MSDUs or A-MSDUs according to the TID, depending on the energy state of the non-AP STA on each of the connections used.

[0153] When the default mode is used, the non-AP-MLD can retrieve BUs buffered by the AP-MLD on any facility connection, although the AP-MLD may recommend a connection.

[0154] A non-AP MLD can retrieve buffered BUs, which are MMPDUs buffered on the AP MLD on each enabled connection. An AP MLD can use each enabled connection to transmit individually addressed, bufferable management frames, which are not measurement MMPDUs, depending on the power state of the non-AP STA on the connection in use.

[0155] If an STA connected to a non-AP MLD is in active mode on a link with a set of TIDs allocated for DL ​​transmission, its associated AP connected to the AP MLD can transmit the following to the STA: MSDUs / A-MSDUs for the set of allocated TIDs for the non-AP MLD; and MMPDUs that are not measurement MMPDUs for the non-AP MLD or the associated STAs, unless the frames are being transmitted to another STA connected to the same non-AP MLD and in active mode.

[0156] As mentioned above, in the standard mapping mode, all TIDs are mapped to all setup connections for DL ​​and UL, and all setup connections are enabled. A non-AP MLD and an AP MLD performing a multi-connection setup should operate in this mode if a TID-to-connection mapping negotiation for another mapping has not occurred, was unsuccessful, or was aborted.

[0157] In a multi-connection (re)establishment procedure, a non-AP MLD can initiate a TID-to-connection mapping negotiation by inserting a TID-to-connection mapping element into a (re)assignment request frame if an AP MLD has specified support for TID-to-connection mapping negotiation.

[0158] After receiving the (re)mapping request frame containing the TID-to-connection mapping element, the AP MLD can respond to the (re)mapping request frame according to the following rules. The AP MLD can only accept the requested TID-to-connection mapping specified in the TID-to-connection mapping element in the received (re)mapping request frame if it accepts the (re)establishment of multiple connections for all connections on which at least one TID is to be mapped. In this case, the non-AP MLD includes a TID-to-connection mapping element in the (re)mapping response frame. Otherwise, the non-AP MLD indicates the rejection of the proposed TID-to-connection mapping by inserting a TID-to-connection mapping element into the (re)mapping request frame that proposes a preferred TID-to-connection mapping.

[0159] After a successful (re-)establishment of multiple connections, an initiating MLD can send an individually addressed TID-to-connection mapping request frame to a responding MLD that has indicated support for negotiating the TID-to-connection mapping.

[0160] Upon receiving the individually addressed TID-to-connection mapping request frame, the responding MLD sends an individually addressed TID-to-connection mapping request frame to the initiating MLD according to the following rules. The responding MLD can accept the requested TID-to-connection mapping specified in the TID-to-connection mapping element in the received TID-to-connection mapping request frame by transmitting a TID-to-connection mapping request frame. Otherwise, the responding MLD can indicate the rejection of the proposed TID-to-connection mapping in the TID-to-connection mapping request frame. The responding MLD can propose a preferred TID-to-connection mapping in the TID-to-connection mapping request frame by including the TID-to-connection mapping element in the TID-to-connection mapping request frame.

[0161] An MLD can propose a preferred TID-to-connection mapping to a peer MLD by sending an unsolicited TID-to-connection mapping request frame that includes a TID-to-connection mapping element.

[0162] If a peer MLD specifies a preferred TID-to-connection mapping, an MLD can consider this preferred mapping when initiating a new TID-to-connection mapping. Furthermore, an AP MLD can consider the traffic flows associated with the non-AP MLD, as well as the capabilities and limitations (if any) of the non-AP MLD.

[0163] If two MLDs have negotiated a TID-to-connection mapping, either MLD can terminate the negotiated TID-to-connection mapping by sending an individually addressed TID-to-connection mapping abort frame. After the abort, the MLDs operate in the default mapping mode.

[0164] When an MLD successfully negotiates a TID-to-link mapping with a peer MLD, both the MLD and the peer MLD update the TID-to-link mapping information for the uplink and / or downlink according to the negotiated TID-to-link mapping.

[0165] If an MLD successfully negotiates an uplink and / or downlink TID-to-connection mapping with a peer MLD, where the bit position i of a "Connection Mapping" field n in the TID-to-Connection Mapping element is set to 0, a TID n must not be assigned to the connection that corresponds to connection ID i in the uplink and / or downlink. If an MLD successfully negotiates an uplink and / or downlink TID-to-connection mapping with a peer MLD, where the bit position i of a "Connection Mapping" field n in the TID-to-Connection Mapping element is set to 1, the TID n is assigned to the connection that corresponds to connection ID i in the uplink and / or downlink.

[0166] Fig. Figure 11 illustrates an example of a TID-to-connection mapping in a multi-connection communication environment. As shown, the multi-connection communication environment includes an AP-MLD with three connected APs and a non-AP-MLD with three connected STAs.

[0167] During or after the establishment of multiple connections, the non-AP MLD and the AP MLD can negotiate a TID-to-connection mapping. The TID-to-connection mapping assigns TIDs on the non-AP MLD UL and DL to establish connections between the AP MLD and the non-AP MLD. As described in Fig. As shown in Figure 11, the TID-to-connection mapping can, for example, map TIDs 0-6 in UL and DL to connection 1 and TID 7 in UL and DL to connection 2. Therefore, connections 1 and 2 are enabled, and connection 3 is disabled. The TID-to-connection mapping negotiation can be performed by exchanging a mapping request / response frame or a TID-to-connection mapping request / response frame between the non-AP MLD and the AP MLD.

[0168] An AP-MLD can announce a mandatory TID-to-connection mapping by inserting a TID-to-connection mapping element into the beacon and probe response frames transmitted by the APs connected to the AP-MLD.

[0169] An AP connected to an AP-MLD can schedule the transmission of a connection recommendation frame to provide a connection recommendation to a group of non-AP-MLDs.

[0170] An AP-MLD uses the TID-to-connection mapping procedures announced in beacon and probe response frames to disable or enable a connection for all associated non-AP-MLDs.

[0171] A non-simultaneous transmit and receive (NSTR) mobile AP MLD is a mobile AP MLD with at least one NSTR link pair. An NSTR link pair is a pair of links corresponding to STAs associated with an MLD for which the receive requirements on one link cannot be met when an STA associated with the MLD transmits on the other link. Each link of such a pair is a member of the NSTR link pair. For example, if an MLD supports transmitting on link 1 simultaneously with receiving on link 2, but cannot support transmitting on link 2 simultaneously with receiving on link 1, then link 1 and link 2 constitute an NSTR link pair for that MLD.

[0172] A simultaneous transmit and receive link pair (STR link pair) is a link pair that is not an NSTR link pair. If a link pair on which an MLD is operating is an STR link pair, then a STA connected to the MLD and operating on a first link in the STR link pair must access the wireless medium on the first link by following the EDCA rules, regardless of any activity on a second link of the STR link pair, unless expressly stated otherwise.

[0173] All connection pairs for an AP-MLD that is not a mobile NSTR-AP-MLD and operates on more than one connection must be STR connection pairs. If an AP-MLD that is not a mobile NSTR-AP-MLD operates on only one connection, all STR requirements and capabilities corresponding to a connection pair no longer apply.

[0174] An AP connected to an AP-MLD that has been granted the right to initiate the transmission of a frame of an AC on a link via the EDCA rules may choose not to transmit a frame corresponding to that AC because interference is to be expected from the transmission at the STA operating on the other link of an NSTR link pair to which the link belongs within the intended non-AP-MLD of the receiver, and because no alternative frame is available in the queue that would not present a possibility for such interference.

[0175] A non-AP STA connected to a non-AP MLD operating on one link of an NSTR link pair, and which has been granted the right to initiate the transmission of an AC frame on one link through EDCA backoff rules, or which is authorized by an AP that is the TXOP holder to use part of the received TXOP through triggered TXOP sharing rules, may choose not to transmit a frame corresponding to that AC due to anticipated interference from the transmission at the non-AP STA operating on the other link of the NSTR link pair within the non-AP MLD, and due to the lack of an alternative frame available in the queue that would not present a possibility for such interference.

[0176] Fig. Figure 12 shows an example of a Multi-AP Network 1200. This example Multi-AP Network 1200 can be a Multi-AP network according to the Wi-Fi Alliance standard specification for Multi-AP networks. As shown in Fig. As shown in Figure 12, the Multi-AP Network 1200 can include a Multi-AP Controller 1202 and a variety of Multi-AP Groups (or Multi-AP Sets or AP Candidate Sets), including the Multi-AP Group 1204, the Multi-AP Group 1206, and the Multi-AP Group 1208.

[0177] The Multi-AP Controller 1202 can be a logical unit that implements logic for controlling the access points (APs) in the Multi-AP Network 1200. The Multi-AP Controller 1202 can receive capability information and measurements from the APs and trigger AP control commands and operations on the APs. The Multi-AP Controller 1202 can also provide onboarding functions for boarding and deploying APs in the Multi-AP Network 1200.

[0178] Multi-AP groups 1204, 1206, and 1208 can each contain multiple APs. APs in a multi-AP group are within communication range of each other. However, the APs in a multi-AP group do not need to share the same primary channel. For the purposes of this text, the primary channel for an AP refers to a standard channel that the AP monitors for management frames and / or uses to transmit beacon frames. For a STA associated with an AP, the primary channel refers to the AP's primary channel, which is announced via the AP's beacon frames.

[0179] In one approach, one of the access points (APs) in a multi-AP group can be designated as the master AP. The master AP can be determined by the Multi-AP Controller 1202 or by the APs themselves within the multi-AP group. The master AP of a multi-AP group can be fixed or change over time among the APs in the group. An AP that is not the master AP of the multi-AP group is designated as a slave AP.

[0180] In this approach, a multi-AP group or AP candidate set is a set of APs that can initiate or participate in multi-AP coordination. An AP in a multi-AP group can participate as a slave AP in multi-AP coordination initiated by a master AP in the same multi-AP group. At least one AP in a multi-AP group must be capable of being a master AP.

[0181] In one approach, access points (APs) within a multi-AP group can coordinate with each other, including coordinating transmissions within the multi-AP group. One aspect of this coordination can include coordinating the execution of multi-AP transmissions within the multi-AP group. In the sense used here, a multi-AP transmission is a transmission event in which multiple APs (of a multi-AP group or a multi-AP network) transmit simultaneously over a period of time. The period of simultaneous AP transmission can be a continuous timeframe.

[0182] Coordination of multi-AP groups can be enabled by the multi-AP controller and / or the master AP of the multi-AP group. In one approach, the multi-AP controller and / or the master AP can control the time and / or frequency allocation within a TXOP. For example, when one of the APs (e.g., the master AP) in the multi-AP group receives a TXOP, the multi-AP controller and / or the master AP can control how the TXOP's time / frequency resources are shared with other APs in the multi-AP group. In one implementation, the AP in the multi-AP group that receives a TXOP becomes the master AP of the multi-AP group. The master AP can then share a portion of its received TXOP (which could be the entire TXOP) with one or more other APs in the multi-AP group.

[0183] Multi-AP operation can be enabled by at least two APs that support multi-AP coordination within one or more multi-AP groups. The APs can support multi-AP transmission schemes in a multi-AP network. A master AP can coordinate with slave APs to enable multi-AP coordination and support multi-AP transmission. Slave AP(s) can participate in a multi-AP transmission. The master AP can select the slave AP(s) suitable for the multi-AP transmission. Slave APs can be candidates for a multi-AP transmission before being assigned by the master AP.

[0184] Multi-AP transmission schemes can include transmission schemes such as coordinated OFDMA, coordinated time division multiple access (TDMA), coordinated spatial reuse, coordinated beamforming, joint transmit or receive (JT / JR), or a combination of two or more of the above schemes.

[0185] Coordinated OFDMA and coordinated TDMA can be categorized as coordinated TXOPs, where the frequency or time resources of a TXOP can be used to coordinate interference. Coordinated Spatial Reuse (CSR) can enable the reuse of the spatial range of neighboring BSSs by adjusting the transmit power of coordinated APs. Coordinated Beamforming (CBF) can provide dedicated zero-point control with spatial radiation based on channel state information (CSI) feedback from coordinated APs using multiple antennas to suppress interference. JT / JR can use shared CSI for distributed MIMO pre-coding or detection of data streams between multiple APs.

[0186] Fig. Figure 13 shows an example network 1300 that includes a coordinated AP set. As in Fig. As shown in Figure 13, the coordinated AP set can include AP 1302-1 and AP 1302-2. The coordinated AP set can be a subset of an established multi-AP group. At least one STA can be assigned to each of APs 1302-1 and 1302-2. For example, STA 1304-1 can be assigned to AP 1302-1 and STA 1304-2 to AP 1302-2.

[0187] APs 1302-1 and 1302-2 can belong to the same ESS, as described above. Fig. As described in section 1, in such a case, APs 1302-1 and 1302-2 can be connected via a DS to support ESS features. Furthermore, APs 1302-1 and 1302-2 can be connected as part of a coordinated AP set via a backhaul. The backhaul is used to quickly share information between APs, thus supporting coordinated transmissions. The shared information can include channel state information or data to be sent to associated STAs. The backhaul can be wired or wireless. For high-capacity information transmission, a wired backhaul is preferred to avoid burdening the APs' main radios. However, a wired backhaul can result in higher deployment costs and greater limitations on AP placement.Wireless backhaul is preferred due to its lower deployment costs and flexibility in AP placement. However, because wireless backhaul relies on the APs' main radios to transmit information, the APs cannot send or receive data while wireless backhaul is in use.

[0188] Normally, one of the APs, 1302-1 and 1302-2, can act as the master AP and the other as the slave AP. The master AP is the AP that owns the TXOP (Transaction Opportunity). During the TXOP, the master AP shares frequency resources with the slave AP. If there are more than two APs in the coordinated set, a master AP can only share its TXOP with a subset of the coordinated AP set. The role of the master AP can change over time. For example, the master AP role can be assigned to a specific AP for a certain period. Similarly, the slave AP role can be dynamically chosen by the master AP or pre-assigned for a specific period.

[0189] Depending on the capabilities of the APs in a coordinated AP set, the APs may only be able to perform certain types of coordinated transfers. For example, if in Fig. While AP 1302-1 supports JT and CSR, and AP 1302-2 supports CSR and CBF, both APs can only perform CSR as a coordinated transfer scheme. An AP may also prefer to perform individual AP transfers for a certain period if the benefits of a coordinated transfer do not outweigh some of its disadvantages, such as reduced flexibility and higher computational demands.

[0190] CSR is a type of multi-AP coordination that can be supported by AP 1301-1 and AP 1302-2, as described in Fig. Figure 13 shows that spatial reuse using CSR can be more robust than non-AP-coordinated spatial reuse schemes such as OBSS-PD-based SR (Overlapping Basic Service Set, OBSS; Packet Detect, PD) and PSR-based SR. For example, in the example network 1300, APs 1302-1 and 1302-2 can perform a joint probing operation to measure path loss (PL) on paths of network 1300. For example, the joint probing operation can result in a measurement of PL 1308 for the path between APs 1302-1 and 1302-2, path loss 1310 for the path between AP 1302-1 and STA 1304-2, and path loss 1312 for the path between AP 1302-2 and STA 1304-1. The measured path loss information can then be shared between APs 1302-1 and 1302-2 (e.g., using the backhaul) to enable simultaneous transmissions by APs 1302-1 and 1302-2 to their associated STAs 1304-1 and 1304-2, respectively.In particular, one of the APs, 1302-1 and 1302-2, receives a TXOP to become the master AP. The master AP can then send a CSR announcement frame to the other APs. In one embodiment, the master AP can perform a polling operation before sending the CSR announcement frame to query the slave APs regarding packet availability for transmission. If at least one slave AP responds and indicates packet availability, the master AP can proceed with sending the CSR announcement frame. In the CSR announcement, the master AP can limit the transmit power of a slave AP to protect its own transmission to its destination STA. The slave AP can similarly protect its own transmission to its destination STA by choosing a modulation scheme that provides a sufficiently high signal-to-interference ratio (SIR) margin to tolerate interference from the master AP's transmission to its destination STA.

[0191] Fig. Figure 14 illustrates Example 1400 of a multi-AP operating procedure. Example 1400 illustrates the multi-AP operating procedure with respect to a multi-AP network that includes APs 1402 and 1404 and STAs 1406 and 1408. In this example, APs 1402 and 1404 can form a multi-AP group. AP 1402 can be the master AP and AP 1404 a slave AP of the multi-AP group. For example, AP 1402 can receive a TXOP that makes it the master AP of the multi-AP group. Alternatively, AP 1402 can be designated as the master AP by a multi-AP controller.

[0192] As in Fig. As shown in Figure 14, the multi-AP operating procedure can include a series of phases over time, each of which can contain a variety of frame exchanges within the multi-AP network. Specifically, the multi-AP operating procedure can include a multi-AP selection phase (1410), a multi-AP data exchange phase (1412), a multi-AP probing phase (1414), and a multi-AP data transmission phase (1416).

[0193] A multi-AP network can operate in multi-AP mode based on a specific multi-AP transmission scheme. The multi-AP transmission scheme can be selected by the master AP based on the capabilities of the slave APs in a multi-AP group. Before multi-AP operation, a slave AP can inform the master AP about capability information related to itself, including its ability to support one or more multi-AP transmission schemes. The slave AP can also inform the master AP about its own BSS (Business Service Server) information and link quality information for any STAs (Connection Safety Devices) associated with it. The master AP can receive information about all available slave APs. This slave AP information can include capability information, BSS information, and link quality information.Based on the information provided by the available slave APs, the master AP can determine, during a multi-AP selection phase, the slave APs to be selected for a multi-AP transmission and a specific multi-AP transmission scheme to be used during the multi-AP transmission.

[0194] The multi-AP selection phase 1410 can include procedures for a master AP to request, select, or assign slave APs for a multi-AP group. As described in Fig. As shown in frame 14, the multi-AP selection phase can include transmissions of frame 618 from AP 1402 and frame 1420 from AP 1404. AP 1402 can transmit frame 1418 to request buffer status information from AP 1404. In response, AP 1404 can transmit frame 1420 to inform AP 1402 about its own buffer status and that of its associated STAs, and / or whether it intends to join the multi-AP operation. The multi-AP selection phase 1410 can also be used to exchange information related to the multi-AP operation, including, for example, BSS information from APs and link quality information between each AP and its associated STAs. An AP's BSS information may include a BSS ID of the AP's BSS, identifiers and / or capabilities of the STAs belonging to the BSS, information on the STAs' probing capabilities, information on the AP's MIMO capabilities, etc.Link quality information can include the received signal strength indicator (RSSI), the signal-to-noise ratio (SNR), the signal-to-interference-plus-noise ratio (SINR), channel status information (CSI), and the channel quality indicator (CQI).

[0195] The multi-AP data exchange phase 1412 can include procedures for sharing data frames that are to be transferred from APs to associated STAs between the master AP and selected slave APs via direct connections between the APs. Phase 1412 may be optional for some multi-AP data transfer schemes. For example, phase 1412 may be required for JT / JR because data frames can be exchanged between APs before or after the multi-AP data transfer phase 1416.

[0196] The Multi-AP Data Exchange Phase 1412 can be performed using a wired backhaul, a wireless in-channel backhaul, or a wireless off-channel backhaul. In some cases, the Multi-AP Data Exchange Phase 1412 can be performed over an in-channel backhaul, for example, using the same wireless channel used to send / receive data to / from STAs. As described in Fig. As shown in Figure 14, AP 1402 in phase 1412 can, for example, transmit a frame 1422 that can be received by AP 1404. Frame 1422 can include MPDUs that AP 1402 wants to transmit to associated STAs using a multi-AP operation. Similarly, AP 1404 can transmit a frame 1424 that can be received by AP 1402. Frame 1424 can include MPDUs that AP 1404 wants to transmit to associated STAs using a multi-AP operation.

[0197] The multi-AP sounding phase 1414 can include multi-AP channel sounding procedures, including channel estimation and feedback of channel estimates between the master AP, the eligible slave APs, and the associated STAs. Phase 1414 may be optional for some multi-AP transmission schemes such as COFDMA, CDTMA, and CSR. For example, phase 1414 can be performed by the master AP to assist in the allocation of resource units when orchestrating a COFDMA transmission.

[0198] The multi-AP data transfer phase 1416 can include the exchange of data frames between the master AP, the slave APs, and their associated STAs based on multi-AP transfer schemes defined by the master AP. Depending on the multi-AP transfer schemes used, phase 1416 can include optional synchronization between APs in the multi-AP group before data frames are exchanged between APs and STAs within the multi-AP group.

[0199] The sequence of phases 1410, 1412, 1414 and 1416 can be determined from the one in Fig. The 14 shown may differ. For example, with COFDMA, phase 1416 may occur immediately after phase 1410, while with JT / JR, phase 1412 may occur after phase 1410. Furthermore, as mentioned above, some phases may be optional and may or may not be present. For example, phase 1414 may not be required for COFDMA, but it is for JT / JR.

[0200] Fig. Figure 15 illustrates an example of a multi-AP exploration phase (1500). Multi-AP exploration phase 1500 can be an example of multi-AP exploration phase 1414. As in Fig. As shown in Figure 15, Example 1500 can include a master AP 1502 and a slave AP 1504 of a multi-AP group. Example 1500 can also include an STA 1506 connected to AP 702 and an STA 1508 connected to AP 1504.

[0201] As in Fig. As shown in Figure 15, the multi-AP probing phase 1500 can comprise frame exchanges to allow AP 1502 (the master AP) to acquire channel state information (CSI) from channels in the multi-AP group. In one implementation, phase 1500 can include a first sub-phase 1510 and a second sub-phase 1512.

[0202] During the first sub-phase 1510, APs can begin channel probing and STAs can estimate CSI. For example, AP 1502 can transmit a frame 1514 to AP 1504 (the slave AP) to initiate a multi-AP probing. Frame 1514 can include a multi-AP trigger frame. Subsequently, APs 1502 and 1504 can each send announcement frames 1516-1 and 1516-2 to their respective associated STAs 1506 and 1508 to announce the transmission of probing frames. Frames 1516-1 and 1516-2 can include multi-AP zero data packet announcement (NDPA) frames. Frames 1516-1 and 1516-2 can be transmitted concurrently. Next, APs 1502 and 1504 can transmit frames 1518-1 and 1518-2 to STAs 1506 and 1508, respectively. Frames 1518-1 and 1518-2 can contain multi-AP null data packet (NDP) frames. STAs 1506 and 1508 receive frames 1518-1 and 1518-2, respectively.1518-2 and perform a channel estimation of the channels from AP 1502 to STA 1506 and from AP 1504 to STA 1508, respectively.

[0203] During the second sub-phase 1512, APs can initiate a process in which STAs report channel estimates back to the APs. For example, AP 1502 can transmit a frame 1520 to trigger STAs 1506 and 1508 to transmit their channel estimates to APs 1502 and 1504, respectively. Frame 1520 can include a multi-AP trigger frame. In response, STAs 1506 and 1508 can each transmit frames 1522 and 1524, including feedback on the channel estimates, to APs 1502 and 1504, respectively. Frames 1522 and 1524 can include NDP feedback frames. The feedback on the channel estimates can include NDP feedback, CSI-related information, a beamforming report (BFR), or a channel quality indication report (CQI).

[0204] Fig. Figure 16 illustrates an example 1600 of a multi-AP downlink data transmission phase. The multi-AP downlink data transmission phase 1600 can be an example of the multi-AP data transmission phase 1516. As in Fig. As shown in Figure 16, Example 1600 can include a master AP 1602 and a slave AP 1604 of a multi-AP group. Example 1600 can further include a STA 1606 connected to AP 1602 and a STA 1608 connected to AP 1604.

[0205] As in Fig. As shown in Figure 16, the multi-AP downlink data transmission phase can include 1600 frame exchanges to enable the master AP 1602 to coordinate with the slave AP 1604 to execute specific multi-AP transmission schemes with their associated STAs 1606 and 1608, respectively. The multi-AP transmission schemes can include COFDMA, CTDMA, CSR, CBF, JT / JR, or a combination of two or more of the schemes mentioned above.

[0206] As in Fig. As shown in Figure 16, master AP 1602 can begin phase 1600 by transmitting a frame 1610 to AP 1604. Frame 1610 can include information about AP 1604 (e.g., an identifier for AP 1604), synchronization information, information about a specific multi-AP transmission scheme to be used, and / or information about a resource unit (RU) for use by AP 1604 to acknowledge frame 1610. Frame 1610 can include a control frame. For example, frame 1610 can include a multi-AP trigger frame.

[0207] Slave AP 1604 can receive frame 1610 and use the synchronization information to synchronize with master AP 1602. APs 1602 and 1604 can then transmit data to their associated STAs 1606 and 1608, respectively. Specifically, AP 1602 can transmit data frame 1612 to its associated STA 1606, and AP 1604 can transmit data frame 1614 to its associated STA 1608. Depending on the multi-AP transmission scheme used, APs 1602 and 1604 can transmit frames 1612 and 1614, respectively, to different STAs in different BSSs. For example, if the multi-AP transmission scheme is JT / JR, AP 1602 can also transmit frame 1612 to STA 1608, which is connected to slave AP 1604, and AP 1604 can also transmit frame 1614 to STA 1608, which is connected to AP 1604. The resources for sending and receiving frames 1612 and 1614 may depend on the specific multi-AP transmission scheme used.

[0208] STAs 1606 and 1608 can acknowledge frames 1612 and 1614, respectively. For example, STA 1606 can transmit frame 1616 to AP 1602, and STA 1608 can transmit frame 1618 to AP 1604. Frames 1616 and 1618 can include block acknowledgment (BA) frames. STAs 1606 and 1608 can also transmit frames 1616 and 1618 to APs in different BSSs if required by the multi-AP transmission scheme in use. For example, if the multi-AP transmission scheme is JT / JR, STA 1606 can also transmit frame 1616 to AP 1604, and STA 1608 can also transmit frame 1618 to AP 1602. The resources required to send and receive frames 1616 and 1618 may depend on the specific multi-AP transmission scheme used.

[0209] Fig. Figure 17 illustrates an example 1700 of a multi-AP uplink data transmission phase. The multi-AP uplink data transmission phase 1700 can be an example of the multi-AP data transmission phase 1516. As in Fig. As shown in Figure 17, Example 1700 can include a master AP 1702 and a slave AP 1704 of a multi-AP group. Example 1700 can further include STAs 1706 and 1708 connected to AP 1702, as well as STA 1710 connected to AP 1704.

[0210] As in Fig. As shown in Figure 17, the multi-AP uplink data transmission phase 1700 can include frame exchanges to enable the master AP 1702 to coordinate with the slave AP 1704 to perform certain multi-AP transmission schemes with the STAs 1706, 1708, and 1710. The multi-AP transmission schemes can include COFDMA, CTDMA, CSR, CBF, JT / JR, or a combination of two or more of the schemes mentioned above.

[0211] As in Fig. As shown in Figure 17, master AP 1702 can begin phase 1700 by transmitting frame 1712 to AP 1704. Frame 1712 can include information about AP 1704 (e.g., an identifier for AP 1704), synchronization information, information about a specific multi-AP transmission scheme to be used, and / or information about a RU for use by AP 1704 to acknowledge frame 1712. Frame 1712 can include a control frame. For example, frame 1712 can include a multi-AP trigger frame.

[0212] Slave AP 1704 can receive frame 1712 and use the synchronization information to synchronize with master AP 1702. Subsequently, APs 1702 and 1704 can request uplink data transmissions from their associated STAs 1706, 1708, and 1710 using trigger frames. Specifically, AP 1702 can transmit a trigger frame 1714 to its associated STAs 1706 and 1708, and AP 1704 can transmit a trigger frame 1716 to its associated STA 1710. Depending on the multi-AP transmission scheme used, APs 1702 and 1704 can also transmit frames 1714 and 1716, respectively, to STAs in different BSSs. For example, if the multi-AP transmission scheme is JT / JR, AP 1702 can also transmit frame 1714 to STA 1710, which is connected to slave AP 1704, and AP 1704 can also transmit frame 1716 to STAs 1706 and 1708, which are connected to AP 1702.The resources required to send and receive frames 1714 and 1716 may depend on the specific multi-AP transmission scheme used.

[0213] STAs 1706 and 1708 can respond to frame 1714, and STA 1710 can respond to frame 1716. For example, STAs 1706 and 1708 can transmit frames 1718 and 1720, respectively, to AP 1702, while STA 1710 can transmit frame 1722 to AP 1704. Frames 1718, 1720, and / or 1722 can be transmitted simultaneously. Frames 1718, 1720, and 1722 can contain data frames or null data frames. STAs 1706, 1708, and 1710 can also transmit frames 1718, 1720, and 1722, respectively, to APs in different BSSs if required by the multi-AP transmission scheme in use. For example, if the multi-AP transmission scheme is JT / JR, STAs 1706 and 1708 can also transmit frames 1718 and 1720 to AP 1704, and STA 1710 can also transmit frame 1722 to AP 1702. The resources required to send and receive frames 1718, 1720, and 1722 may depend on the specific multi-AP transmission scheme used.

[0214] Fig. Figure 18 illustrates an example of a multi-AP information exchange phase (1800). Multi-AP information exchange phase 1800 can be an example of multi-AP information exchange phase 946. As in Fig. As shown in Figure 18, Example 1800 can include a master AP 1802 and a slave AP 1812 in a multi-AP group. In one example, AP 1802 and AP 1812 might have exchanged beacon frames in a previous phase (e.g., multi-AP setup phase 940). AP 1812 can be a candidate for a slave AP if phase 1800 occurs during a multi-AP setup phase or before AP 1812 is selected or designated as a slave AP in a subsequent multi-AP selection phase (e.g., multi-AP selection phase 950). Conversely, AP 1812 can be a designated slave AP if phase 1800 occurs (or recurs) after AP 1812 has been selected or designated as a slave AP in a multi-AP selection phase.

[0215] As in Fig. As shown in Figure 18, phase 1800 can include subphases 1840 and 1850. For example, during subphase 1840, AP 1802 could send frame 1842 to AP 1812 to request BSS information from AP 2. Frame 1842 could be a BSS information request frame. In response, AP 1812 could send frame 1844 to AP 1802, containing AP 1812's BSS information. Frame 1844 could be a BSS information response frame.

[0216] In one example, during subphase 1850, AP 1802 can send another frame 1852 to AP 1812 to request link quality information. In response, AP 1812 can send frame 1854 to AP 1802, which includes the requested link quality information. Frame 1852 could be a response frame containing link quality information.

[0217] The Target Wake Time (TWT) introduced in the IEEE 802.11ah standard allows STAs to control activity in the BSS by scheduling them to operate at different times to reduce conflicts. TWTs can also reduce the required operating time for an STA using a power-saving mode. TWTs can be individual or broadcast. Individual TWTs follow a TWT agreement negotiated between the STAs. Broadcast TWTs are based on a schedule set by an AP and provided to the STAs.

[0218] A TWT session can be negotiated between an AP and a STA. The TWT session can configure a TWT service period (SP) for downlink (DL) and uplink (UL) traffic between the AP and the STA. Limited traffic is to be expected within the negotiated SP. The TWT SP can start at a specific time. The TWT SP can run for a specified SP duration. The TWT SP can repeat itself at each SP interval.

[0219] Fig. Figure 19 illustrates an example TWT operation 1900. The TWT operation 1900 includes an AP 1902, a STA 1904, and a STA 1906. The AP 1902 and the STA 1904 could define a TWT-SP 1920. The AP 1902 and the STA 1906 could define a TWT-SP 1922. The TWT-SP 1920 and the TWT-SP 1922 can be configured as shown in Fig. Repeat as shown in 10, so that the TWT-SP 1920 can include a first TWT-SP 1920-1 and a second TWT-SP 1920-2, and that the TWT-SP 1922 can include a first TWT-SP 1922-1 and a second TWT-SP 1922-2.

[0220] The AP 1902 and the STA 1904 can exchange frames during the first TWT-SP 1920-1. The STA 1904 can enter a sleep state at the end of TWT-SP 1920-1 and remain in sleep mode until the start of TWT-SP 1920-2. The start of the second TWT-SP 1920-2 can be indicated by a TWT wake-up interval of 1930, which is associated with TWT-SP 1920. The AP 1902 and the STA 1904 could exchange frames again during the second TWT-SP 1920-2.

[0221] Similarly, the AP 1902 and the STA 1906 can exchange frames during the first TWT-SP 1922-1. The STA 1906 can enter a sleep state at the end of the first TWT-SP 1922-1 and remain in sleep mode until the beginning of the second TWT-SP 1922-2. The beginning of the second TWT-SP 1922-2 can be indicated by a TWT wake-up interval 1932, which is linked to the first TWT-SP 1922. The AP 1902 and the STA 1906 could exchange frames again during the second TWT-SP 1922-2.

[0222] In its awake state, a STA can be fully powered. The STA can send and / or receive frames to and from an AP or another STA. In its idle state, an STA cannot send or receive data packets to or from an AP or another STA.

[0223] The restricted TWT operation (R-TWT operation) allows STAs in a BSS to use improved mechanisms for protecting media access and reserving resources for the delivery of latency-sensitive data.

[0224] An R-TWT membership is set up using the same procedure as a Broadcast-TWT membership, except that the Broadcast-TWT element(s) transmitted in the TWT setup frame include one or more restricted fields "TWT parameter set".

[0225] The R-TWT planning AP and the R-TWT planned STA should configure the "Restricted TWT Traffic Info" field to identify the TID(s) that carry latency-sensitive traffic in the downlink and uplink for the R-TWT membership to be established.

[0226] The TID(s) marked as latency-sensitive traffic in DL and UL in the "Restricted TWT Traffic Info" field must be within the set of TIDs assigned in DL and UL, respectively, to the connection on which R-TWT membership is established. The TID(s) specified in the "Restricted TWT Traffic Info" field of the TWT element in a TWT response indicating "Accept TWT" are referred to as R-TWT DL TID(s) or R-TWT UL TID(s), and collectively as R-TWT TID(s).

[0227] If an update to the TID-to-connection mapping results in a mapping where none of the R-TWT TID(s) for an R-TWT membership is assigned to the connection on which the R-TWT membership was established, the corresponding R-TWT membership is considered to be resolved.

[0228] An R-TWT scheduled STA can signal a QoS property element for a traffic stream to be delivered during the R-TWT SPs of an R-TWT schedule in a Stream Classification Service (SCS) request framework to the R-TWT scheduling AP according to the procedures.

[0229] When an R-TWT scheduling AP receives QoS property elements from an R-TWT scheduled STA whose "TID and Direction" fields match an R-TWT TID and its specified direction for an R-TWT membership facility, the R-TWT scheduling AP can use these parameters in the QoS property element(s) as a guideline for the R-TWT membership facility.

[0230] The Stream Classification Service (SCS) is a service that an access point (AP) can provide to its associated service access points (STAs) that support SCS. Within the SCS system, the AP classifies incoming, individually addressed MSDUs based on parameters provided by the non-AP STA.

[0231] The SCS procedure is used by a non-AP-MLD to describe the classification of incoming, individually addressed MSDUs to an AP-MLD based on parameters provided by the non-AP-MLD and / or their traffic characteristics.

[0232] An EHT-STA establishes an SCS stream with an EHT-AP, as defined in the SCS procedures.

[0233] A non-AP EHT STA can send an SCS request frame with SCS descriptor element(s) containing a QoS property element if the "Request Type" field in the frame is set to "Add" or "Modify." The "QoS Properties" element describes the traffic properties of the requested SCS stream. A non-AP EHT STA cannot send an SCS request frame with SCS descriptor element(s) containing a QoS property element to an AP from which it has not received an EHT capability element with a value of 1 for the "SCS Traffic Support" field.

[0234] The MLDs manage SCSIDs at the MLD level, meaning that the SCSID used by a non-AP STA connected to a non-AP MLD in an SCS request frame sent to an AP connected to an AP MLD is unique for all STAs connected to the non-AP MLD.

[0235] All STAs connected to an MLD must set the SCS field of the "Extended Capabilities" element they transmit to the same value. The SCSID is used by a non-AP MLD to request the creation, modification, or deletion of an SCS stream. The SCSID is used by an AP MLD to identify an SCS stream in SCS responses.

[0236] An SCS request frame sent from a non-AP STA connected to a non-AP MLD to the AP of an AP MLD, and containing a QoS property element where the "Direction" subfield is set to Uplink or Downlink, or containing no QoS property element, is interpreted as a request to create an SCS stream that applies at the MLD level.

[0237] The QoS property element serves as a reference for scheduling the EHT AP. An EHT AP should schedule the transmission of downlink frames to meet the latency limit and the requested minimum data rate for downlink data frames when the "Direction" subfield of the QoS property element specifies "Downlink". An EHT AP should allow the transmission of uplink frames from the EHT STA at an interval between the requested minimum and maximum service intervals, and the AP should meet the requested minimum data rate when the "Direction" subfield of the QoS property element specifies "Uplink". An EHT AP should allow the transmission of direct link frames from the EHT STA to another STA on the connection specified in the "ConnectionID" subfield of the "Control Info" field at an interval between the requested minimum and maximum service intervals.

[0238] If the EHT-STA is a TWT-scheduled STA or a TWT-requesting STA, and TWT-SPs have been negotiated with the EHT-AP for the TID specified in the QoS property element, the EHT-AP should ensure that the service interval matches the negotiated TWT wake-up intervals.

[0239] If the EHT STA is an R-TWT scheduled STA and negotiated R-TWT SPs exist for the TID specified in the QoS property element, then the EHT AP should use these R-TWT SPs to handle traffic corresponding to the TID and the direction specified in the QoS property element. If the negotiated R-TWT SPs for the TID specified in the QoS property element are trigger-enabled R-TWTs, the EHT AP should ensure that the trigger frames are scheduled at the beginning of the R-TWT SPs.

[0240] Fig. Figure 20 illustrates an example of a Multi-AP Network 2000 that supports an MLO. As shown in Fig. As shown in Figure 20, the exemplary Multi-AP Network 2000 includes an AP 2002, an AP 2004, a STA 2006, and a STA 2008. APs 2002 and 2004 can form a coordinated AP set. The coordinated AP set can be a subset of an established Multi-AP group. AP 2002 and / or AP 2004 can include an AP MLD. In one example, AP 2002 includes a linked AP STA 2002-1 and a linked AP STA 2002-2. In another example, AP 2004 includes a linked AP STA 2004-1 and a linked AP STA 2004-2.

[0241] At least one STA can be assigned to each of the APs 2002 and 2004. For example, STA 2006 can be assigned to AP 2002, and STA 2008 can be assigned to AP 2004. STA 2006 and STA 2008 can each include a non-AP MLD. In one example, STA 2006 includes a linked non-AP STA 2006-1 and a linked non-AP STA 2006-2. In another example, STA 2008 includes a linked non-AP STA 2008-1 and a linked non-AP STA 2008-2.

[0242] In one example, AP-MLDs or non-AP-MLDs can communicate over multiple connections, such as a first connection and a second connection. In this example, the first connection could use a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band yet to be defined. Similarly, the second connection could use a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band yet to be defined, but the second connection would be different from the first.

[0243] In one example, AP-STA 2002-1, AP-STA 2004-1, non-AP-STA 2006-1, and non-AP-STA 2008-1 are operated on the first connection (connection 1). In another example, non-AP-STA 2006-1 is assigned to AP-STA 2002-1. In yet another example, non-AP-STA 2008-1 is assigned to AP-STA 2004-1. In yet another example, AP-STA 2002-2, AP-STA 2004-2, non-AP-STA 2006-2, and non-AP-STA 2008-2 are operated on the second connection (connection 2). In yet another example, non-AP-STA 2006-2 is assigned to AP-STA 2002-2. In one example, the non-AP-STA 2008-2 is assigned to the AP-STA 2008-2.

[0244] In one example, APs 2002 and 2004 can belong to the same ESS, as above in Fig. 1 described. In such a case, APs 2002 and 2004 can be connected via a DS to support ESS features. Additionally, APs 2002 and 2004 can be connected as part of a coordinated AP set via a backhaul. As described in Fig. As shown in Figure 20, an example multi-AP network 2000 can use a wireless backhaul to connect APs 2002 and 2004 via links 1 and 2. In one example, AP-STAs 2002-1 and 2004-1 belong to different Basic Service Sets (BSSs). In another example, AP-STAs 2002-2 and 2004-2 belong to different BSSs.

[0245] Future IEEE 802.11 standards are expected to provide various mechanisms to support the Quality of Service (QoS) requirements of low-latency (LL) (or latency-sensitive) traffic. This traffic may originate from various real-time applications with stringent latency requirements (e.g., very low average latency, worst-case latency on the order of a few to a few tens of milliseconds, and / or low jitter). In operation, LL traffic may be associated with one or more traffic identifiers (TIDs), which in turn may be associated with one or more predefined access categories (ACs) or traffic streams (hereinafter referred to as LL-TIDs). The one or more predefined ACs may, for example, include access categories for video (AC_VI) and voice (AC_VO).

[0246] Fig. Figure 21 illustrates an example of a multi-AP procedure 2100 in a multi-connection environment. As shown in Fig. As shown in Figure 21, the exemplary multi-AP procedure 2100 includes an AP 2102, an AP 2104, and a STA 2106. The AP 2102 and the AP 2104 can form a coordinated AP set. The coordinated AP set can be a subset of an established multi-AP group. The AP 2102 and / or AP 2104 can include an AP MLD. In one example, the AP 2102 includes a linked AP STA 2102-1 and a linked AP STA 2102-2. In another example, the AP 2104 includes a linked AP STA 2104-1 and a linked AP STA 2104-2. As shown in Figure 21, the AP 2104 includes a linked AP STA 2104-1 and a linked AP STA 2104-2. Fig. As shown in Figure 21, STA 2106 can be connected to AP 2102. STA 2106 can include a non-AP MLD. In one example, STA 2106 includes a connected non-AP STA 2106-1 and a connected non-AP STA 2106-2. In another example, AP STA 2102-1, AP STA 2104-1, and non-AP STA 2106-1 operate on a first connection (Connection 1). In another example, non-AP STA 2106-1 is associated with AP STA 2102-1. In yet another example, AP STA 2102-2, AP STA 2104-2, and non-AP STA 2106-2 operate on a second connection (Connection 2). In one example, the non-AP-STA 2106-2 is assigned to the AP-STA 2102-2.

[0247] In one example, APs 2102 and 2104 can belong to the same ESS, as shown above. Fig. 1 described. In such a case, APs 2102 and 2104 can be connected via a DS to support ESS features. Additionally, APs 2102 and 2104 can be connected as part of a coordinated AP set via a backhaul. As described in Fig. As shown in Figure 21, an example multi-AP procedure 2100 can use a wireless backhaul to connect APs 2102 and 2104 via links 1 and 2. In one example, AP-STAs 2102-1 and 2104-1 belong to different BSSs. In another example, AP-STAs 2102-2 and 2104-2 belong to different BSSs.

[0248] Example 2100 assumes that AP 2102 and STA 2106 have established a multi-connection setup. During multi-connection setup, AP 2102 can classify traffic between AP 2102 and STA 2106 into one or more categories based on the traffic's latency requirements. For example, AP 2102 can classify traffic between AP 2102 and STA 2106 into a first and second category. The first category might include low-latency traffic, while the second category might include traffic that does not have low latency. In one example, AP 2102 negotiates a TID-to-connection mapping with STA 2106 to assign traffic flows to available connections. In another example, AP 2102 can prioritize different connections based on the traffic category.For example, AP 2102 can prioritize connection 2 over connection 1 for the transmission of Category 1 traffic. In one example, a Category 1 traffic stream between AP 2102 and STA 2106 can be assigned to connection 2.

[0249] In one example, as in Fig. As shown in Figure 21, AP 2104 can send frame 2112 to AP 2102 via connection 2 at time T1. Frame 2112 could be an AP-to-AP frame. For example, the AP-to-AP frame can be used for multi-AP coordination between AP 2104 and AP 2102. In one example, STA 2106 could receive frame 2112 and determine its NAV based on frame 2112. Accordingly, STA 2106 can postpone the transmission of frame 2122, which includes first-category traffic, from time T2 to time T3 if its NAV indicates idle time. If the first-category traffic includes low-latency traffic, this traffic may be delayed. In another example, STA 2106 might not receive frame 2112 and therefore transmit frame 2122 to AP 2102 at time T2.Frame 2122 can therefore collide or interfere with frame 2112 at AP 2102, resulting in a failure to receive one or more frames.

[0250] Embodiments of the present disclosure, as described below, address the problems of existing multi-AP procedures described above. In one embodiment, a first AP receives a first frame from a second AP, indicating the priority of a first connection among a plurality of connections, over which the second AP can transmit first-category traffic. In another embodiment, the first AP can transmit a second frame containing second-category traffic over a second connection among the plurality of connections, the second connection being selected based on priority. This reduces interference and latency for first-category traffic.

[0251] Fig. Figure 22 illustrates an example 2200 for a multi-AP coordination procedure in a multi-connection environment according to one embodiment. Example 2200 is for illustrative purposes only and is not limiting. As in Fig. As shown in Figure 22, Example 2200 includes APs 2202 and 2204 and a STA 2206. AP 2202 and / or AP 2204 may include an AP-MLD. STA 2206 may include a non-AP-MLD. In one example, AP 2202 includes a connected AP-STA 2202-1 and a connected AP-STA 2202-2. In another example, AP 2204 includes a connected AP-STA 2204-1 and a connected AP-STA 2204-2. In another example, STA 2206 includes a connected non-AP-STA 2206-1 and a connected non-AP-STA 2206-2. In one example, AP-STA 2202-1, AP STA 2204-1, and non-AP STA 2206-1 are operated on a first connection (Connection 1). In this example, the first connection can use a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined later. In this example, non-AP-STA 2206-1 is assigned to AP-STA 2202-1.In one example, AP-STA 2202-2, AP-STA 2204-2, and non-AP-STA 2206-2 are operated on a second connection (Connection 2). The second connection can be a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future, and the second connection is different from the first.

[0252] In one example, APs 2202 and 2204 might belong to the same ESS. In such a case, APs 2202 and 2204 can be connected via a DS to support ESS features. Furthermore, APs 2202 and 2204 can be connected as part of a coordinated AP set via a backhaul. For example, as shown in Fig. Figure 22 shows that APs 2202 and 2204 are connected via a wireless backhaul network comprising Link 1 and Link 2. In one example, the non-AP STA 2206-2 is associated with AP STA 2202-2. In another example, AP STAs 2202-1 and 2204-1 belong to different BSSs. In yet another example, AP STAs 2202-2 and 2204-2 belong to different BSSs.

[0253] In one embodiment, the AP 2202 and the AP 2204 can form a multi-AP group. In one example, the AP-STA 2202-1 and the AP-STA 2204-1 form a multi-AP group. In another example, the AP-STA 2202-2 and the AP-STA 2204-2 form a multi-AP group.

[0254] Example 2200 assumes that AP 2202 and STA 2206 have established a multi-connection setup. During multi-connection setup, AP 2202 can classify traffic between AP 2202 and STA 2206 into one or more categories based on the traffic's latency requirements. For example, AP 2202 can classify traffic between AP 2202 and STA 2206 into a first and second category. The first category might include low-latency traffic, while the second category might include traffic that does not have low latency. In one example, AP 2202 negotiates a TID-to-connection mapping with STA 2206 to assign traffic flows to available connections. In another example, AP 2202 can prioritize different connections based on the traffic category.For example, the AP 2202 can prioritize connection 2 over connection 1 for the transmission of first category data traffic.

[0255] As in Fig. As shown in Figure 22, Example 2200 can begin with AP 2202 transmitting a first frame 2212 to AP 2204 at time T0. In one embodiment, the first frame 2212 specifies the priority of connection 2 for communication of category 1 traffic over connection 2 by AP 2202. That is, the priority of connection 2 represents the priority that connection 2 is used by AP 2202 for transmitting category 1 traffic over connection 2. In one embodiment, the first frame 2212 is transmitted over either connection 1 or connection 2. In Example 2200, the first frame 2212 is transmitted over connection 1. The first frame 2212 could be an AP-to-AP frame. For example, an AP-to-AP frame can be used for multi-AP coordination between AP 2202 and AP 2204.

[0256] In one embodiment, the priority of connection 2 can indicate that the AP 2202 transmits only first-category traffic over connection 2. In another embodiment, the priority of connection 2 can indicate that the AP 2202 does not transmit first-category traffic over connection 2.

[0257] In one example, a first-category traffic stream between AP 2202 and STA 2206 can be assigned to connection 2. In one embodiment, the first category includes low-latency traffic.

[0258] In one embodiment, the first frame 2212 can further specify a priority for connection 1 for communication of first-category traffic over connection 1 by AP 2202. In one example, the priority of connection 1 can be lower than the priority of connection 2. That is, AP 2202 prioritizes the use of connection 2 over the use of connection 1 for communication of first-category traffic by AP 2202.

[0259] In one embodiment, the first frame 2212 can comprise a management frame. In one embodiment, the management frame can be a beacon frame. In another embodiment, the management frame can be an action frame.

[0260] In one embodiment, the AP 2204 can transmit a frame 2214 over connection 1 in response to the first frame 2212. In another embodiment, the AP 2204 may not transmit a frame in response to the first frame 2212 if the first frame 2212 is a beacon frame.

[0261] In one embodiment, the AP 2204 can have second-category traffic for transmission to the AP 2202. The second category can include traffic that does not have low latency. For example, the second-category traffic can include AP-to-AP traffic used for coordination between the AP 2202 and the AP 2204.

[0262] In one embodiment, the AP 2204 can select between connection 1 and connection 2 for transmitting second-category traffic. In another embodiment, the AP 2202 can select between connection 1 and connection 2 for transmitting second-category traffic based on the priority of connection 1 and / or the priority of connection 2 specified in the first frame 2212. In one embodiment, the AP 2204 selects connection 1 based on the priority of connection 2. For example, the priority of connection 2 might indicate that connection 2 is used by the AP 2202 exclusively for first-category traffic. In another embodiment, the AP 2204 selects connection 1 based on the priority of both connection 2 and connection 1. In one example, the AP 2204 compares the priority of connection 2 with the priority of connection 1.For example, the priority of connection 2 may be higher than the priority of connection 1. Therefore, the AP 2202 may select connection 1 instead of connection 2 to transmit traffic that does not belong to the first category, such as traffic of the second category.

[0263] In example 2200, AP 2204 transmits a second frame 2216, containing the second category traffic, to AP 2202 via connection 1. As in Fig. As shown in Figure 22, the second frame 2216 can be received by AP 2202 at time T1. The second frame 2216 can be an AP-to-AP frame. For example, the AP-to-AP frame can be used for multi-AP coordination between AP 2202 and AP 2204. In one example, AP 2202 can transmit a frame 2218 over link 1 in response to the second frame 2216.

[0264] In Example 2200, Category 1 traffic can arrive at STA 2206 for transmission to AP 2202 before or after time T1. For example, if AP 2204 selects connection 1 for transmitting the second frame 2216, STA 2206 can be activated to transmit frame 2222, containing Category 1 traffic, to AP 2202 via connection 2. In one example, starting at time T2, STA 2206 can transmit frame 2222 to AP 2202 via connection 2, while AP 2202 receives frame 2216 from AP 2204 via connection 1. This allows Category 1 traffic to be delivered successfully and promptly to AP 2202.

[0265] Fig. Figure 23 illustrates another example 2300 for a multi-AP coordination procedure in a multi-connection environment according to one embodiment. Example 2300 is for illustrative purposes only and is not limiting. As in Fig. As shown in Figure 23, Example 2300 includes APs 2302 and 2304 and a STA 2306. AP 2302 and / or AP 2304 may include an AP-MLD. STA 2306 may include a non-AP-MLD. In one example, AP 2302 includes a connected AP-STA 2302-1 and a connected AP-STA 2302-2. In another example, AP 2304 includes a connected AP-STA 2304-1 and a connected AP-STA 2304-2. In another example, STA 2306 includes a connected non-AP-STA 2306-1 and a connected non-AP-STA 2306-2. In yet another example, AP-STA 2302-1, AP STA 2304-1, and non-AP STA 2306-1 operate on a first link (Link 1). The first connection can be from the 2.4 GHz band, the 5 GHz band, the 6 GHz band, or a band to be defined in the future. In one example, non-AP-STA 2306-1 is assigned to AP-STA 2302-1. In another example, AP-STA 2302-2, AP-STA 2304-2, and non-AP-STA 2306-2 are operated on a second connection (Connection 2).The second connection can include a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future, and the second connection will be different from the first connection.

[0266] In one example, APs 2302 and 2304 might belong to the same ESS. In such a case, APs 2302 and 2304 can be connected via a DS to support ESS features. Additionally, APs 2302 and 2304 can be connected as part of a coordinated AP set via a backhaul. For example, as shown in Fig. Figure 23 shows that APs 2302 and 2304 are connected via a wireless backhaul network comprising Link 1 and Link 2. In one example, non-AP-STA 2306-2 is assigned to AP-STA 2302-2. In another example, AP-STAs 2302-1 and 2304-1 belong to different BSSs. In yet another example, AP-STAs 2302-2 and 2304-2 belong to different BSSs.

[0267] In one embodiment, AP 2302 and AP 2304 can form a multi-AP group. In one example, AP-STA 2302-1 and AP-STA 2304-1 form a multi-AP group. In another example, AP-STA 2302-2 and AP-STA 2304-2 form a multi-AP group.

[0268] Example 2300 assumes that AP 2302 and STA 2306 have established a multi-connection setup. During multi-connection setup, AP 2302 can classify traffic between AP 2302 and STA 2306 into one or more categories based on the traffic's latency requirements. For example, AP 2302 can classify traffic between AP 2302 and STA 2306 into a first and second category. The first category might include low-latency traffic, while the second category might include traffic that does not have low latency. In one example, AP 2302 negotiates a TID-to-connection mapping with STA 2306 to assign traffic flows to available connections. In another example, AP 2302 can prioritize different connections based on traffic category.For example, the AP 2302 can prioritize connection 2 over connection 1 for the transmission of first category data traffic.

[0269] As in Fig. As shown in Figure 23, Example 2300 can begin with AP 2304 transmitting a frame 2310 over connection 2 to AP 2302 to request a first frame 2312 from AP 2302. In one embodiment, AP 2302 transmits the first frame 2312 to AP 2304 in response to frame 2310 at time T0. In another embodiment, the first frame 2312 indicates the priority of connection 2 for communicating category 1 traffic over connection 2 by AP 2302. That is, the priority of connection 2 represents the priority that connection 2 is used by AP 2302 for transmitting category 1 traffic over connection 2. In one embodiment, the first frame 2312 is transmitted over either connection 1 or connection 2. In Example 2300, the first frame 2312 is transmitted over connection 1. The first frame, 2312, could be an AP-to-AP frame.For example, an AP-to-AP frame can be used for multi-AP coordination between AP 2302 and AP 2304.

[0270] In one embodiment, the priority of connection 2 can indicate that the AP 2302 transmits only first-category data traffic over connection 2. In another embodiment, the priority of connection 2 can indicate that the AP 2302 does not transmit first-category data traffic over connection 2.

[0271] In one example, a first-category traffic stream between AP 2302 and STA 2306 can be assigned to connection 2. In one embodiment, the first category includes low-latency traffic.

[0272] In one embodiment, the first frame 2312 can further specify a priority for connection 1 for communication of first-category traffic over connection 1 by AP 2302. In one example, the priority of connection 1 can be lower than the priority of connection 2. That is, AP 2302 prioritizes the use of connection 2 over the use of connection 1 for communication of first-category traffic by AP 2302.

[0273] In one embodiment, the first frame 2312 can comprise a management frame. In one embodiment, the management frame can be a beacon frame. In another embodiment, the management frame can be an action frame.

[0274] In one embodiment, the AP 2304 can transmit a frame 2314 over connection 1 in response to the first frame 2312. In another embodiment, the AP 2304 might not transmit a frame in response to the first frame 2312 if the first frame 2312 is a beacon frame.

[0275] In one embodiment, the AP 2304 can have second-category traffic for transmission to the AP 2302. The second category can include traffic that does not have low latency. For example, the second-category traffic can include AP-to-AP traffic used for coordination between the AP 2302 and the AP 2304.

[0276] In one embodiment, the AP 2304 can select between connection 1 and connection 2 for transmitting second-category traffic. In another embodiment, the AP 2302 can select between connection 1 and connection 2 for transmitting second-category traffic based on the priority of connection 1 and / or the priority of connection 2 specified in the first frame 2312. In one embodiment, the AP 2304 selects connection 1 based on the priority of connection 2. For example, the priority of connection 2 might indicate that connection 2 is used by the AP 2302 exclusively for first-category traffic. In another embodiment, the AP 2304 selects connection 1 based on the priority of both connection 2 and connection 1. In one example, the AP 2304 compares the priority of connection 2 with the priority of connection 1.For example, the priority of connection 2 may be higher than the priority of connection 1. Therefore, the AP 2302 may select connection 1 instead of connection 2 to transmit traffic that does not belong to the first category, such as traffic of the second category.

[0277] In example 2300, AP 2304 transmits a second frame 2316, containing the second category traffic, to AP 2302 via connection 1. As in Fig. As shown in Figure 23, the second frame 2316 can be received by AP 2302 at time T1. The second frame 2316 can be an AP-to-AP frame. For example, the AP-to-AP frame can be used for multi-AP coordination between AP 2302 and AP 2304. In one example, AP 2302 can transmit a frame 2318 over link 1 in response to the second frame 2316.

[0278] In example 2300, first-category traffic can arrive at STA 2306 for transmission to AP 2302 before or after time T1. If, in another example, AP 2304 selects connection 1 for transmitting the second frame 2316, STA 2306 can be activated to transmit frame 2322, containing first-category traffic, to AP 2302 via connection 2. In yet another example, starting at time T2, STA 2306 can transmit frame 2322 to AP 2302 via connection 2, while AP 2302 receives frame 2316 from AP 2304 via connection 1. This allows first-category traffic to be delivered successfully and promptly to AP 2302.

[0279] Fig. Figure 24 illustrates another example 2400 for a multi-AP coordination procedure in a multi-connection environment according to one embodiment. Example 2400 is for illustrative purposes only and is not limiting. As in Fig. As shown in Figure 24, Example 2400 includes AP 2402, AP 2404, and STA 2406. AP 2402 and / or AP 2404 may include an AP-MLD. STA 2406 may include a non-AP-MLD. In one example, AP 2402 includes a connected AP-STA 2402-1 and a connected AP-STA 2402-2. In another example, AP 2404 includes a connected AP-STA 2404-1 and a connected AP-STA 2404-2. In another example, STA 2406 includes a connected non-AP-STA 2406-1 and a connected non-AP-STA 2406-2. In one example, AP-STA 2402-1, AP STA 2404-1, and non-AP STA 2406-1 are operated on a first connection (Connection 1). This first connection can be from the 2.4 GHz band, the 5 GHz band, the 6 GHz band, or a band to be defined in the future. In this example, non-AP STA 2406-1 is assigned to AP-STA 2402-1.In one example, the AP-STA 2402-2, the AP-STA 2404-2, and the non-AP-STA 2406-2 are operated on a second connection (Connection 2). The second connection can be a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future, and the second connection is different from the first connection.

[0280] In one example, APs 2402 and 2404 might belong to the same ESS. In such a case, APs 2402 and 2404 can be connected via a DS to support ESS features. Additionally, APs 2402 and 2404 can be connected as part of a coordinated AP set via a backhaul. For example, as shown in Fig. Figure 24 shows that AP 2402 and AP 2404 are connected via a wireless backhaul network comprising Link 1 and Link 2. In one example, non-AP-STA 2406-2 is assigned to AP-STA 2402-2. In another example, AP-STAs 2402-1 and 2404-1 belong to different BSSs. In yet another example, AP-STAs 2402-2 and 2404-2 belong to different BSSs.

[0281] In one embodiment, the AP 2402 and the AP 2404 can form a multi-AP group. In one example, the AP-STA 2402-1 and the AP-STA 2404-1 form a multi-AP group. In another example, the AP-STA 2402-2 and the AP-STA 2404-2 form a multi-AP group.

[0282] Example 2400 assumes that AP 2402 and STA 2406 have established a multi-connection setup. During multi-connection setup, AP 2402 can classify traffic between AP 2402 and STA 2406 into one or more categories based on the traffic's latency requirements. For example, AP 2402 can classify traffic between AP 2402 and STA 2406 into a first and second category. The first category might include low-latency traffic, while the second category might include traffic that does not have low latency. In one example, AP 2402 negotiates a TID-to-connection mapping with STA 2406 to assign traffic flows to available connections. In another example, AP 2402 can prioritize different connections based on traffic category.For example, the AP 2402 can prioritize connection 2 over connection 1 for the transmission of first category data traffic.

[0283] In one example, AP 2402 can schedule an R-TWT session with STA 2406 to enable STA 2406 to deliver Category 1 traffic. For instance, prior to the start of Example 2400, AP 2402 and STA 2406 can exchange TWT setup request / response frames to establish an R-TWT SP 2442 for a TID associated with Category 1 traffic.

[0284] In one example, as in Fig. As shown in Figure 24, Example 2400 can begin with a Stream Classification Service (SCS) between STA 2406 and AP 2402. The SCS procedure allows STA 2406 to signal to AP 2402 a QoS property element for a traffic stream to be delivered during the R-TWT-SPs of an R-TWT schedule. More specifically, STA 2406 can transmit a request frame 2422 over connection 2 to AP 2402 to inform AP 2402 about a Category 1 traffic stream to STA 2406. In one example, frame 2422 can be an SCS request frame. For instance, frame 2422 includes a QoS property element specifying R-TWT-SP 2442 and a TID for the Category 1 traffic. In response to frame 2422, AP 2402 can transmit a response frame 2424 that accepts the SCS request contained in frame 2422. For example, frame 2424 can be an SCS response frame.

[0285] Then, as in Fig. As shown in Figure 24, AP 2402 transmits a first frame 2412 to AP 2404 at time T0. In one embodiment, the first frame 2412 indicates the priority of connection 2 for communicating category 1 traffic over connection 2 by AP 2402. That is, the priority of connection 2 represents the priority that connection 2 is used by AP 2402 for transmitting category 1 traffic over connection 2. In one embodiment, the first frame 2412 is transmitted over either connection 1 or connection 2. In Example 2400, the first frame 2412 is transmitted over connection 1. The first frame 2412 could be an AP-to-AP frame. For example, an AP-to-AP frame can be used for multi-AP coordination between AP 2402 and AP 2404.

[0286] In one embodiment, the priority of connection 2 means that the AP 2402 transmits only Category 1 data traffic over connection 2. In another embodiment, the priority of connection 2 means that the AP 2402 does not transmit any Category 1 data traffic over connection 2.

[0287] In one example, a first-category traffic stream between AP 2402 and STA 2406 can be assigned to connection 2. In one embodiment, the first category includes low-latency traffic.

[0288] In one embodiment, the first frame 2412 can further specify a priority for connection 1 for communication of first-category traffic over connection 1 by AP 2402. In one example, the priority of connection 1 can be lower than the priority of connection 2. That is, AP 2402 prioritizes the use of connection 2 over the use of connection 1 for communication of first-category traffic by AP 2402.

[0289] In one embodiment, the first frame 2412 further includes a period 2440 for the communication of first-category data traffic over connection 2 by the AP 2402. As in Fig. As shown in Figure 24, period 2440 can begin earlier than R-TWT-SP 2442 and end later than R-TWT-SP 2442. In one example, period 2440 can coincide with R-TWT-SP 2442. In another example, period 2440 can be used to protect the transmission of Category 1 traffic on connection 2 between AP 2402 and STA 2406. For instance, by including period 2440 in the first frame 2412, AP 2402 can prevent AP 2404 from using connection 2 for non-Category 1 data communication during period 2440.

[0290] In one embodiment, the first frame 2412 can comprise a management frame. In one embodiment, the management frame can be a beacon frame. In another embodiment, the management frame can be an action frame.

[0291] In one embodiment, the AP 2404 may not transmit a frame 2414 in response to the first frame 2412 if the first frame 2412 is a beacon frame.

[0292] In one embodiment, the AP 2404 can have second-category traffic for transmission to the AP 2402. The second category can include traffic that does not have low latency. For example, the second-category traffic can include AP-to-AP traffic used for coordination between the AP 2402 and the AP 2404.

[0293] In one embodiment, the AP 2404 can select between connection 1 and connection 2 for transmitting second-category traffic. In another embodiment, the AP 2402 can select between connection 1 and connection 2 for transmitting second-category traffic based on the priority of connection 1, the priority of connection 2, and / or the time period 2440 specified in the first frame 2412. In one embodiment, the AP 2404 can select connection 1 based on the priority of connection 2 and the time period 2440. For example, the priority of connection 2 and the time period 2440 can indicate that the time period 2440 on connection 2 is used by the AP 2402 exclusively for first-category traffic. In yet another embodiment, the AP 2404 can select connection 1 based on the priority of connection 2, the priority of connection 1, and the time period 2440.In one example, AP 2404 could compare the priority of connection 2 with the priority of connection 1 within the time period 2440. For instance, the priority of connection 2 within the time period 2440 might be higher than the priority of connection 1. Therefore, AP 2402 could select connection 1 instead of connection 2 within the time period 2440 to transmit traffic that does not belong to the first category, such as traffic of the second category.

[0294] In example 2400, AP 2404 can transmit a second frame 2416, which includes the second category of data traffic, over connection 1 within the time period 2440. As in Fig. As shown in Figure 24, the second frame, 2416, can be received by AP 2402 at time T1. The second frame, 2416, can be an AP-to-AP frame. For example, the AP-to-AP frame can be used for multi-AP coordination between AP 2402 and AP 2404. In one example, AP 2402 can transmit a frame, 2418, over link 1 in response to frame 2416.

[0295] In Example 2400, first-category traffic can arrive at STA 2406 for transmission to AP 2402 before or after time T1. If, in another example, AP 2404 selects connection 1 for transmitting the second frame 2416, STA 2406 can be activated to transmit frame 2426, containing first-category traffic, to AP 2402 via connection 2. In yet another example, starting at time T2, STA 2406 can transmit frame 2426 to AP 2402 via connection 2, while AP 2402 receives frame 2416 from AP 2404 via connection 1. This allows first-category traffic to be delivered successfully and promptly to AP 2402.

[0296] Fig. Figure 25 illustrates another example 2500 for a multi-AP coordination procedure according to one embodiment. Example 2500 is for illustrative purposes only and is not limiting. As in Fig. As shown in Figure 25, Example 2500 includes AP 2502, AP 2504, and STA 2506. AP 2502 and / or AP 2504 may include an AP-MLD. STA 2506 may include a non-AP-MLD. In one example, AP 2502 includes a linked AP-STA 2502-1 and a linked AP-STA 2502-2. In another example, AP 2504 includes a linked AP-STA 2504-1 and a linked AP-STA 2504-2. In another example, STA 2506 includes a linked non-AP-STA 2506-1 and a linked non-AP-STA 2506-2. In one example, AP-STA 2502-1, AP STA 2504-1, and non-AP STA 2506-1 are operated on a first connection (Connection 1). This first connection can be from the 2.4 GHz band, the 5 GHz band, the 6 GHz band, or a band to be defined in the future. In this example, non-AP-STA 2506-1 is assigned to AP-STA 2502-1.In one example, the AP-STA 2502-2, the AP-STA 2504-2, and the non-AP-STA 2506-2 are operated on a second connection (Connection 2). The second connection can be a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future, and the second connection is different from the first connection.

[0297] In one example, APs 2502 and 2504 might belong to the same ESS. In such a case, APs 2502 and 2504 can be connected via a DS to support ESS features. Additionally, APs 2502 and 2504 can be connected as part of a coordinated AP set via a backhaul. For example, as shown in Fig. Figure 25 shows that AP 2502 and AP 2504 are connected via a wireless backhaul network comprising Link 1 and Link 2. In one example, non-AP-STA 2506-2 is assigned to AP-STA 2502-2. In another example, AP-STAs 2502-1 and 2504-1 belong to different BSSs. In yet another example, AP-STAs 2502-2 and 2504-2 belong to different BSSs.

[0298] In one embodiment, the AP 2502 and the AP 2504 can form a multi-AP group. In one example, the AP-STA 2502-1 and the AP-STA 2504-1 form a multi-AP group. In another example, the AP-STA 2502-2 and the AP-STA 2504-2 form a multi-AP group.

[0299] Example 2500 assumes that AP 2502 and STA 2506 have established a multi-connection setup. During multi-connection setup, AP 2502 can classify traffic between AP 2502 and STA 2506 into one or more categories based on the traffic's latency requirements. For example, AP 2502 can classify traffic between AP 2502 and STA 2506 into a first and second category. The first category might include low-latency traffic, while the second category might include traffic that does not have low latency. In one example, AP 2502 negotiates a TID-to-connection mapping with STA 2506 to assign traffic flows to available connections. In another example, AP 2502 can prioritize different connections based on traffic category.For example, the AP 2502 can prioritize connection 2 over connection 1 for the transmission of first category data traffic.

[0300] In one example, AP 2502 can schedule an R-TWT session with STA 2506 to enable STA 2406 to deliver Category 1 traffic. For instance, prior to the start of Example 2500, AP 2502 and STA 2506 can exchange TWT setup request / response frames to establish an R-TWT SP 2542 for a TID associated with Category 1 traffic.

[0301] In one example, as in Fig. As shown in Figure 25, Example 2500 can begin with an SCS procedure between STA 2506 and AP 2502. The SCS procedure allows STA 2506 to signal a QoS property element for a traffic stream to be delivered during the R-TWT-SPs of an R-TWT schedule.

[0302] More specifically, STA 2506 can transmit a request frame 2522 over connection 2 to AP 2502 to inform AP 2502 about a Category 1 traffic stream to STA 2506. For example, frame 2522 could be an SCS request frame. For instance, frame 2522 might include a QoS property element specifying R-TWT-SP 2542 and a TID for Category 1 traffic. In response to frame 2522, AP 2502 could transmit a response frame 2524 that accepts the SCS request contained in frame 2522. For example, frame 2524 could be an SCS response frame.

[0303] Then, as in Fig. As shown in Figure 25, AP 2502 transmits a first frame 2512 to AP 2504 at time T0. In one embodiment, the first frame 2512 indicates the priority of connection 2 for communication of category 1 traffic over connection 2 by AP 2502. That is, the priority of connection 2 represents the priority that connection 2 is used by AP 2502 for transmitting category 1 traffic over connection 2. In one embodiment, the first frame 2512 is transmitted over either connection 1 or connection 2. In Example 2500, the first frame 2512 is transmitted over connection 1. The first frame 2512 could be an AP-to-AP frame. For example, an AP-to-AP frame can be used for multi-AP coordination between AP 2502 and AP 2504.

[0304] In one embodiment, the priority of connection 2 means that the AP 2502 transmits only Category 1 traffic over connection 2. In another embodiment, the priority of connection 2 means that the AP 2502 does not transmit any Category 1 traffic over connection 2.

[0305] In one example, a first-category traffic stream between AP 2502 and STA 2506 can be assigned to connection 2. In one embodiment, the first category includes low-latency traffic.

[0306] In one embodiment, the first frame 2512 can further specify a priority for connection 1 for communication of category 1 traffic over connection 1 by AP 2502. In one example, the priority of connection 1 can be lower than the priority of connection 2. That is, AP 2502 prioritizes the use of connection 2 over the use of connection 1 for communication of category 1 traffic by AP 2502.

[0307] In one embodiment, the first frame 2512 further includes a period 2540 for the communication of first-category data traffic over connection 2 by the AP 2502. As in Fig. As shown in Figure 25, period 2540 can begin earlier than R-TWT-SP 2542 and end later than R-TWT-SP 2542. In one example, period 2540 can coincide with R-TWT-SP 2542. In another example, period 2540 can be used to protect the transmission of Category 1 traffic on connection 2 between AP 2502 and STA 2506. For instance, by including period 2540 in the first frame 2512, AP 2502 can prevent AP 2504 from using connection 2 for non-Category 1 data communication during period 2540.

[0308] In one embodiment, the first frame 2512 can comprise a management frame. In one embodiment, the management frame can be a beacon frame. In another embodiment, the management frame can be an action frame.

[0309] In one embodiment, the AP 2504 may not transmit a frame 2514 in response to the first frame 2512 if the first frame 2512 is a beacon frame.

[0310] In one embodiment, the AP 2504 can have second-category traffic for transmission to the AP 2502. The second category can include traffic that does not have low latency. For example, the second-category traffic can include AP-to-AP traffic used for coordination between the AP 2502 and the AP 2504.

[0311] As in Fig. As shown in Figure 25, AP 2504 may be busy on connection 1 during period 2540. In one embodiment, AP 2504 can select between connection 1 and connection 2 for transmitting second-category traffic. In another embodiment, AP 2502 can select between connection 1 and connection 2 for transmitting second-category traffic based on the priority of connection 1, the priority of connection 2, and / or the period 2540 specified in the first frame 2512. In yet another embodiment, AP 2504 can select connection 2 based on the priority of connection 2 and the period 2540. For example, the priority of connection 2 and the period 2540 may indicate that AP 2502 will use the period 2540 on connection 2 exclusively for first-category traffic.In another embodiment, AP 2504 can select connection 2 based on the priority of connection 2, the priority of connection 1, and the time period 2540. For example, AP 2504 could compare the priority of connection 2 with the priority of connection 1 within the time period 2540. For instance, the priority of connection 2 within the time period 2540 might be higher than the priority of connection 1. For example, AP 2504 might be busy on connection 1 within the time period 2540. Therefore, after the time period 2540, AP 2504 can select connection 2 instead of connection 1 to transmit traffic that does not belong to the first category, such as traffic of the second category.

[0312] In example 2500, AP 2504 can transmit a second frame 2516, which includes the second category traffic, over connection 2 within the time period 2540. As in Fig. As shown in Figure 25, the second frame, 2516, can be received by AP 2502 at time T3 after the end of period 2540. Frame 2516 could be an AP-to-AP frame. For example, the AP-to-AP frame can be used for multi-AP coordination between AP 2502 and AP 2504. In one example, AP 2502 can transmit frame 2518 over link 2 in response to frame 2516. In another example, AP 2502 can transmit frame 2518 over link 1 in response to frame 2516.

[0313] In Example 2500, first-category traffic can arrive at STA 2506 for transmission to AP 2502 before or after time T1. If, in another example, AP 2504 selects connection 2 for transmitting the second frame 2516, STA 2506 can be activated to transmit frame 2526, containing first-category traffic, to AP 2502 via connection 2. In yet another example, STA 2506 can transmit frame 2526 to AP 2502 via connection 2, starting at time T2, before AP 2502 receives frame 2516 via connection 2 at time T3. This allows first-category traffic to be delivered successfully and promptly to AP 2502.

[0314] In one embodiment, the in Fig. The first frame described in 2212, which is in Fig. The first frame described in 2312, which is in Fig. The first frame 2412 described in 24 and the one in Fig. The first frame described in 2512 may be management frames such as beacon frames.

[0315] Fig. Figure 26 illustrates an exemplary Beacon Frame 2600, which can be used according to embodiments. For example, Beacon Frame 2600 can be an embodiment of Frames 2212, 2312, 2412, and 2512. In one embodiment, Beacon Frame 2600 can specify the priority of a first connection among a plurality of connections for the transmission of first-category traffic over the first connection by an access point (AP). The first connection can be from the 2.4 GHz band, the 5 GHz band, the 6 GHz band, or a band to be defined in the future. In another embodiment, Beacon Frame 2600 can further specify the priority of a second connection among a plurality of connections for the transmission of first-category traffic over the second connection by an access point (AP).The second connection can include a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future, and the second connection is different from the first connection. In one embodiment, the Beacon Frame 2600 can further include a period for the AP to transmit first-category traffic over the first connection.

[0316] As in Fig. As shown in Figure 26, the beacon frame 2600 can include a "Frame Control" field, a "Duration" field, one or more "Address" fields, a "Sequence Control" field, an "HT Control" field, a frame body, and an "FCS" field. In one embodiment, the frame body can include an element 2602 that specifies the priority of the first connection. In one example, the element 2602 could include an "Element Identifier" (ID) field 2604, a "Length" field 2606, an "Element ID Extension" field 2608, and an "Information" field 2610. In another embodiment, the frame body can include another element such as element 2602 to specify the priority of the second connection.

[0317] For example, the field 2Information" 2610 could include a subfield "Connection priority" 2612 and an optional subfield "Connection period" 2614.

[0318] In one embodiment, the subfield "Connection Priority" 2612 can include the priority of the first connection. In another embodiment, the subfield "Connection Priority" 2612 can also include the priority of the second connection. In one implementation, the subfield "Connection Priority" 2612 can include at least one value from a list of priority values. In one implementation, a higher (or lower) priority value means that the connection has a higher priority for communicating Category 1 traffic through the AP. In another implementation, the subfield "Connection Priority" 2612 can take the value 0 or 1, where the value 1 indicates that the first connection is reserved for Category 1 traffic through the AP.

[0319] In one embodiment, the subfield "Connection Priority" 2614 can include the time period for the AP to transmit first-category traffic over the first connection. In another implementation, the subfield "Connection Period" 2614 can include a start time and a duration of the period.

[0320] In another implementation, the subfield "Connection period" 2614 can include a start time and an end time of the period.

[0321] In one embodiment, the in Fig. The first frame described in 2212, which is in Fig. The first frame described in 2312, which is in Fig. The first frame 2412 described in 24 and the one in Fig. The first frame described in 2512 is a management frame, such as an action frame.

[0322] Fig. Figure 27 illustrates an exemplary action frame 2700 that can be used according to embodiments. For example, action frame 2700 can be an embodiment of frames 2212, 2312, 2412, and / or 2512. In one example, action frame 2700 can be a public action frame. In one embodiment, action frame 2700 can include the priority of a first connection among a plurality of connections, over which an AP can transmit first-category traffic via the first connection. The first connection can include one from the 2.4 GHz band, the 5 GHz band, the 6 GHz band, or a band to be defined in the future. In another embodiment, action frame 2700 can further specify the priority of a second connection among a plurality of connections for the transmission of first-category traffic over the second connection by an AP.The second connection can include a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future, and the second connection is different from the first connection. In one embodiment, the action frame 2700 can further include a period for the AP to transmit first-category traffic over the first connection.

[0323] As in Fig. As shown in Figure 27, the action frame 2700 can include an "Action" field 2702. In one embodiment, the "Action" field 2702 can include a "Category" subfield 2704 to specify a connection priority. In one example, the "Action" field 2702 can include an "Action Details" field 2706. In another example, the "Action Details" field 2706 can include a "Connection Priority" subfield 2708 and an optional "Connection Period" subfield 2710.

[0324] In one embodiment, the "Connection Priority" subfield 2708 can include the priority of the first connection. In another embodiment, the "Connection Priority" subfield 2708 can also include the priority of the second connection. In one implementation, the "Connection Priority" subfield 2708 can include at least one value from a list of priority values. In one implementation, a higher (or lower) priority value means that the connection has a higher priority for first-category traffic communication through the AP. In another implementation, the "Connection Priority" subfield 2708 can take the value 0 or 1, where the value 1 indicates that the first connection is reserved for first-category traffic communication through the AP.

[0325] In one embodiment, the subfield "Connection Priority" 2710 can include the period for the AP to transmit Category 1 traffic over the first connection. In one implementation, the subfield "Connection Period" 2710 can include a start time and a duration of the period. In another implementation, the subfield "Connection Period" 2710 can include a start time and an end time of the period.

[0326] As a person skilled in the art would understand from the teachings contained herein, the embodiments described in the preceding examples can easily be extended to cases involving more than two APs.

[0327] As a person skilled in the art would understand from the teachings contained herein, the embodiments described in the preceding examples can easily be extended to cases involving more than two APs.

[0328] Fig. Figure 28 illustrates an example process 2800 according to one embodiment. The example process 2800 serves only for illustration and does not represent a limitation of the embodiments. The process 2800 can be performed by a first AP.

[0329] As in Fig. As shown in Figure 28, process 2800 begins with step 2802, which includes the first AP receiving a first frame from a second AP, where a first frame indicates a priority of a first link of a multitude of links over which the second AP can transmit traffic of a first category over the first link.

[0330] In one embodiment, receiving the first frame includes receiving the first frame over a first connection or a second connection. In one embodiment, the priority of the first connection specifies that the second AP transmits only first-category traffic over the first connection. In another embodiment, the priority of the first connection specifies that the second AP does not transmit any first-category traffic over the first connection. For example, the first connection may be a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future. Likewise, the second connection may be a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future, with the second connection being different from the first connection.

[0331] In one embodiment, a first-category traffic stream is assigned to the first connection at the second AP. In one embodiment, the first-category traffic includes low-latency traffic. In another embodiment, the first-category traffic includes the traffic between the second AP and a first STA assigned to the second AP.

[0332] In one embodiment, the first frame further specifies the priority of the second connection for the transmission of first-category traffic over the second connection by the second AP.

[0333] In one embodiment, the first frame further includes a period for the transmission of first-category traffic over the first connection by the second AP.

[0334] In one embodiment, the first frame comprises a management frame. In another embodiment, the management frame comprises a beacon frame with an element that specifies the priority of the first connection. In yet another embodiment, the management frame comprises an action frame that includes an action field specifying the priority of the first connection.

[0335] In an embodiment which further includes the transmission of a third frame by the first AP to the second AP in order to request the first frame.

[0336] In an embodiment which further includes the transmission of a fourth frame by the first AP to the second AP in response to the first frame.

[0337] In step 2804, process 2800 includes transmitting a second frame containing data of a second category from the first AP to the second AP via a second connection from the multitude of connections, the second connection being selected based on the priority of the first connection.

[0338] In one embodiment, transmitting the second frame includes transmitting the second frame to the second AP or to a second STA. In another embodiment, the second category of data traffic includes the data traffic between the first AP and the second AP.

[0339] In one embodiment, the first AP and the second AP form a multi-AP group.

[0340] In one embodiment, the first AP or the second AP or the APs comprise a multi-link device (MLD).

[0341] Fig. Figure 29 illustrates an example process 2900 according to one embodiment. Example process 2900 serves only for illustration and does not represent a limitation of the embodiments. Process 2900 can be performed by a first AP.

[0342] As in Fig. As shown in Figure 29, process 2900 begins with step 2902, which includes the transmission of a first frame by the first AP to a second AP, where a first frame indicates the priority of a first connection among a multitude of connections over which the first AP can transmit traffic of a first category over the first connection.

[0343] In one embodiment, transmitting the first frame includes transmitting the first frame over either the first link or the second link. In one embodiment, the priority of the first link indicates that the first AP transmits only first-category traffic over the first link. In another embodiment, the priority of the first link indicates that the first AP does not transmit any first-category traffic over the first link. For example, the first link may be a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future. Similarly, the second link may be a 2.4 GHz band, a 5 GHz band, a 6 GHz band, or a band to be defined in the future, with the second link being different from the first link.

[0344] In one embodiment, a first-category traffic stream is assigned to the first connection at the first AP. In one embodiment, the first-category traffic includes low-latency traffic.

[0345] In one embodiment, the first frame further specifies the priority of the second connection for the transmission of first-category traffic over the second connection by the first AP.

[0346] In one embodiment, the first frame further includes a period for the transmission of first-category traffic over the first connection by the first AP.

[0347] In one embodiment, the first frame comprises a management frame. In another embodiment, the management frame comprises a beacon frame with an element that specifies the priority of the first connection. In yet another embodiment, the management frame comprises an action frame that includes an action field specifying the priority of the first connection.

[0348] In an embodiment which further includes receiving a third frame from the second AP to the second AP in order to request the first frame.

[0349] In an embodiment which further includes the first AP receiving a fourth frame from the second AP in response to the first frame.

[0350] In step 2904, process 2900 includes receiving a second frame containing data of a second category by the first AP from the second AP via a second connection of the multitude of connections, the second connection being selected based on the priority of the first connection.

[0351] In one embodiment, receiving the second frame includes receiving the second frame from the first AP. In another embodiment, the second category of data traffic includes the data traffic between the first AP and the second AP.

[0352] In one embodiment, the first AP and the second AP form a multi-AP group.

[0353] In one embodiment, the first AP or the second AP or the APs comprise a multi-link device (MLD).

Claims

[1] Procedure, encompassing: Received, through a first access point (AP) from a second AP, of a first frame that indicates the priority of a first connection of a multitude of connections for the transmission of first-category traffic over the first connection by the second AP; Select, by the first AP and based on the priority of the first connection, a second connection from the multitude of connections to deliver traffic of a second category to the second AP; and Transmitted, through the first AP to the second AP and over the second connection, a second frame that includes the second category of traffic. [2] Procedure, comprehensive: Received, through a first access point (AP) from a second AP, a first frame that indicates the priority of a first connection among a multitude of connections for the transmission of first-category traffic over the first connection by the second AP; and Transmitted, through the first AP, via a second connection of the multitude of connections, a second frame, which includes traffic of a second category, with the second connection being selected based on the priority of the first connection. [3] Method according to claim 1 or 2, wherein the transmission of the second frame comprises the transmission of the second frame to the second AP or to a first STA. [4] Method according to any one of claims 1 to 3, wherein receiving the first frame comprises receiving the first frame via a first connection or the second connection. [5] Method according to any one of claims 1 to 4, wherein the priority of the first connection indicates that the second AP transmits only first category traffic over the first connection. [6] Method according to any one of claims 1 to 4, wherein the priority of the first connection indicates that the second AP does not transmit any first category traffic over the first connection. [7] Method according to any one of claims 1 to 4, wherein a data traffic stream of the first category is assigned to the first connection at the second AP. [8] Method according to any one of claims 1 to 7, wherein the data traffic of the first category comprises low-latency data traffic. [9] Method according to any one of claims 1 to 8, wherein the data traffic of the first category comprises the data traffic between the second AP and a second STA assigned to the second AP. [10] Method according to any one of claims 1 to 9, wherein the data traffic of the second category comprises the data traffic between the first AP and the second AP. [11] Method according to any one of claims 1 to 10, wherein the first frame further specifies a priority of the second connection for the transmission of first category traffic over the second connection by the second AP. [12] Method according to any one of claims 1 to 11, wherein the first frame further comprises a period for the transmission of first category traffic over the first connection by the second AP. [13] Method according to any one of claims 1 to 12, wherein the first frame comprises a management frame. [14] Method according to claim 13, wherein the management frame comprises a beacon frame which includes an element that specifies the priority of the first connection. [15] Method according to claim 13, wherein the management frame comprises an action frame which includes an action field that specifies the priority of the first connection. [16] Method according to any one of claims 1 to 15, further comprising transmitting a third frame by the first AP to the second AP to request the first frame. [17] Method according to any one of claims 1 to 13, 15 and 16, further comprising the transmission of a fourth frame by the first AP to the second AP in response to the first frame. [18] Procedures, in full: Received, through a first access point (AP) to a second AP, a first frame that indicates the priority of a first connection among a multitude of connections for the transmission of first-category traffic over the first connection by the first AP; and Received, by the first AP from the second AP, via a second connection of the multitude of connections, a second frame, which includes traffic of a second category, with the second connection being selected based on the priority of the first connection. [19] Method according to claim 18, wherein receiving the second frame comprises receiving the second frame from the first AP. [20] Method according to any one of claims 18 to 19, wherein the transmission of the first frame comprises the transmission of the first frame over the first connection or the second connection. [21] Method according to any one of claims 18 to 19, wherein the priority of the first connection indicates that the first AP transmits only first category data traffic over the first connection. [22] Method according to any one of claims 18 to 21, wherein the priority of the first connection indicates that the first AP does not transmit any first category traffic over the first connection. [23] Method according to any one of claims 18 to 22, wherein a data traffic stream of the first category is assigned to the first connection at the first AP. [24] Method according to any one of claims 18 to 23, wherein the data traffic of the first category comprises low-latency data traffic. [25] Method according to any one of claims 18 to 24, wherein the data traffic of the first category comprises the data traffic between the first AP and an STA associated with the first AP. [26] Method according to any one of claims 18 to 25, wherein the second category data traffic comprises the data traffic between the first AP and the second AP. [27] Method according to any one of claims 18 to 26, wherein the first frame further specifies a priority of the second connection for the transmission of first category traffic over the second connection by the first AP. [28] Method according to any one of claims 18 to 27, wherein the first frame further comprises a period for the transmission of first category traffic over the first connection by the first AP. [29] Method according to any one of claims 18 to 28, wherein the first frame comprises a management frame. [30] Method according to claim 29, wherein the management frame comprises a beacon frame which includes an element that specifies the priority of the first connection. [31] Method according to claim 29, wherein the management frame comprises an action frame which includes an action field that specifies the priority of the first connection. [32] Method according to any one of claims 18 to 31, further comprising receiving a third frame by the first AP from the second AP in order to request the first frame. [33] Method according to any one of claims 18 to 29, 31 and 32, further comprising receiving a fourth frame by the first AP from the second AP in response to the first frame. [34] Method according to any one of claims 1 to 33, wherein the first AP and the second AP form a multi-AP group. [35] Method according to any one of claims 1 to 34, wherein the first AP or the second AP comprises a multiple connection device (MLD). [36] Device designed to act as a first access point (AP) and to perform operations, comprising: Receiving a first frame from a second AP, indicating the priority of a first connection among a multitude of connections for the transmission of first-category traffic over the first connection by the second AP; and Transmitted, via a second connection of the multitude of connections, a second frame, which includes traffic of a second category, where the second connection is selected based on the priority of the first connection. [37] Device according to claim 36, designed to select the second connection for the transmission of the second category. [38] Device according to claim 36 or 37, wherein the data traffic of the second category is transmitted in a second frame. [39] System comprising a device and a second AP according to any one of claims 36 to 38. [40] Computer program product stored on a computer-readable medium and designed, when running on a processor, to execute the method according to any one of claims 1 to 35.

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