Enables legacy (non-EHT) stations to operate on the conditional link of the soft AP MLD.

Abstract

A wireless communication protocol to enable legacy (non-EHT) stations (STAs) to operate on a conditional link of a softAP MLD. The legacy devices can connect and establish link connections on the conditional link, and a scheduler is configured to allow the legacy STAs to use the conditional link without IDC interference issues on the softAP MLD. The enhanced protocol utilizes a collaborative HCCA schedule created for simultaneous transmission and reception over the primary and conditional links, or an adaptive poll-based schedule performed for the conditional link in response to a link status of the primary link.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to U.S. Patent Application Serial No. 17 / 737,255, filed May 5, 2022, the entire contents of which are incorporated herein by reference. This application also claims priority and benefit to U.S. Provisional Patent Application Serial No. 63 / 208,551, filed June 9, 2021, the entire contents of which are incorporated herein by reference.

[0003] Statements regarding federally funded research or development are not applicable.

[0004] Notice of copyright protection for the material

[0005] Under the copyright laws of the United States and other countries, some materials in this patent document may be protected by copyright. The copyright holder does not object to any person facsimile of this patent document or patent publication as published in any document or record publicly available at the Patent and Trademark Office, but otherwise reserves all copyright. The copyright holder hereby does not waive any right to maintain the confidentiality of this patent document, including but not limited to its rights under 37C.FR §1.14. Background Technology 1. Technical Field

[0007] The technology disclosed herein generally relates to wireless network protocols for operation on multi-link device (MLD) stations, and more specifically to conditional links that enable legacy (non-EHT) MLD stations to use soft access point MLDs.

[0008] 2. Background Technical Discussion

[0009] The Hybrid Coordination Function (HCF) was introduced in IEEE 802.11e to provide Quality of Service (QoS) for real-time applications. This protocol uses Enhanced Distributed Channel Access (EDCA) for contention-based transmission and Controlled Channel Access (HCF Controlled Channel Access (HCCA)) for contention-free transmission. EDCA defines multiple Access Classes (ACs) that include AC-specific Contention Window (CW) sizes, Arbitrated Inter-Frame Space (AIFS) values, and Transmission Opportunity (TXOP) limits to support MAC-level QoS and prioritization. These standards target stations with Extremely High Throughput (EHT) designed to provide Wi-Fi via the 2.4 GHz, 5 GHz, and 6 GHz bands.

[0010] Under this protocol, soft AP MLDs are designed to typically communicate only with legacy (non-EHT) STAs on the basic link to prevent in-device coexistence (IDC) interference; thus, the achievable quality of service and performance are limited.

[0011] Therefore, the ability of legacy (non-EHT) devices to operate on these advanced networks is severely limited.

[0012] Therefore, there is a need for advanced means of handling soft AP issues when enabling legacy (non-EHT) stations. This disclosure addresses these needs and provides additional benefits. Summary of the Invention

[0013] This disclosure discloses a protocol that allows non-EHT legacy STAs to operate on conditional links of a soft AP MLD, for example, configurable for High Throughput (HT), Very High Throughput (VHT), or High Efficiency (HE) protocols. Legacy devices can connect and establish link connections on conditional links via active or passive scanning. If no IDC interference issues are introduced at the soft AP MLD, the scheduler is configured to allow legacy STAs to use conditional links.

[0014] In previous protocols, to prevent IDC interference on the soft AP side, the soft AP MLD protocol could only communicate with legacy (non-EHT) STAs on the basic link; this reduced the quality of service and throughput of legacy STAs due to the limitation of their channel resources.

[0015] This enhanced protocol allows for overcoming these problems using two main approaches. In the first approach, cooperative HCCA scheduling is created for simultaneous transmission and reception on both the base link and the conditional link. In the second approach, adaptive polling-based scheduling is performed on the conditional link based on the base link state.

[0016] Further aspects of the technology described herein will be set forth in the following sections of the specification, wherein the detailed description is intended to fully disclose preferred embodiments of the technology and not to impose limitations thereon. Attached Figure Description

[0017] The techniques described herein will be more fully understood by referring to the following figures, which are for illustrative purposes only:

[0018] Figure 1 is a communication diagram of the Controlled Access Phase (CAP), which shows the HCF Controlled Channel Access (HCCA) Transmission Opportunity (TXOP) and the Enhanced Distributed Channel Access (EDCA) TXOP within the CAP, in which legacy STAs use the Distributed Coordination Function (DCF) for access.

[0019] Figure 2 is a communication diagram of a typical polling TXOP.

[0020] Figure 3 is a diagram of the data fields in the QoS(+)CF polling frame format.

[0021] Figure 4 is a diagram of the data fields of the Traffic Specification (TSPEC) element used for admission control in Parametric Quality of Service (QoS).

[0022] Figure 5 is a data field diagram depicting the subfields within the TS information field shown in Figure 4.

[0023] Figure 6 This is a hardware block diagram of wireless station (STA) hardware according to at least one embodiment of the present disclosure.

[0024] Figure 7 It is a hardware block diagram of a station configuration, such as that included in a multi-link device (MLD) hardware, according to at least one embodiment of the present disclosure.

[0025] Figure 8 This is a general multi-link network topology according to at least one embodiment of the present disclosure.

[0026] Figure 9 It is a network topology including a general multi-link connection of soft AP MLDx and non-AP MLDy according to at least one embodiment of the present disclosure.

[0027] Figure 10A and Figure 10B This is a communication diagram of cooperative HCCA scheduling for NSTR on the basic link and conditional link according to at least one embodiment of the present disclosure.

[0028] Figure 11 This is a communication diagram of admission control based on frame switching of ADDTS based on non-triggered TXOP, according to at least one embodiment of the present disclosure.

[0029] Figure 12A and Figure 12B This is a communication diagram of a TS established by trigger-based TXOP cascading according to at least one embodiment of the present disclosure.

[0030] Figure 13 This is a communication diagram illustrating a second solution for Tx and Rx in an EDCATXOP between a soft AP MLD and a non-AP MLD, according to at least one embodiment of the present disclosure.

[0031] Figure 14 This is a communication diagram of legacy stations LSx and LSM operating on a basic link and a conditional link according to at least one embodiment of the present disclosure.

[0032] Figure 15 This is a communication diagram of another example of legacy stations LSx and LSM operating on a basic link and a conditional link according to at least one embodiment of this disclosure.

[0033] Figure 16 This is a communication diagram illustrating another example of operation on a base link and a conditional link according to at least one embodiment of the present disclosure.

[0034] Figures 17A to 17E This is a flowchart of communication between the soft AP MLD and LS during EDCA TXOP according to at least one embodiment of the present disclosure.

[0035] Figure 18 This is a communication diagram of simultaneously scheduled UL / DL TXOPs according to at least one embodiment of the present disclosure.

[0036] Figure 19 This is a flowchart of cooperative scheduling on a basic link and a conditional link having a duration HCCA TXOP, according to at least one embodiment of the present disclosure.

[0037] Figure 20 This is a topology diagram of example 1-3-1 of the problem of recovering from unexpected reception in the case of a hidden terminal, according to at least one embodiment of the present disclosure.

[0038] Figure 21 The communication diagram is an example 1-3-1 illustrating a solution embodiment for a collision problem caused by a hidden AP, according to at least one embodiment of the present disclosure.

[0039] Figure 22 This is a topology diagram of Example 1-3-2 regarding the problem of recovery from unexpected reception in a hidden terminal under CFP conditions, according to at least one embodiment of the present disclosure.

[0040] Figure 23 This is a communication diagram illustrating an example 1-3-2 of a recovery scheme embodiment for a collision problem caused by a hidden terminal in a CFP initiating HCCATXOP, according to at least one embodiment of the present disclosure.

[0041] Figure 24 It is a communication graph of adaptive polling-based scheduling on a conditional link based on basic link state, according to at least one embodiment of the present disclosure.

[0042] Figure 25 This is a communication diagram of Example 2-1, which utilizes UL TXOP alignment according to at least one embodiment of the present disclosure.

[0043] Figure 26 This is a communication diagram of Example 2-2, which utilizes DL TXOP alignment according to at least one embodiment of the present disclosure.

[0044] Figures 27A to 27D This is a flowchart of a TXOP scheduled on a conditional link based on a basic link state according to at least one embodiment of the present disclosure. Detailed Implementation

[0045] 1. Introduction

[0046] 1.1. Hybrid Coordination Function (HCF)

[0047] IEEE 802.11e proposes providing QoS for real-time applications. It consists of Enhanced Distributed Channel Access (EDCA) for contention-based transmissions and Controlled Channel Access (HCF Controlled Channel Access (HCCA)) for contention-free transmissions.

[0048] 1.2. HCF Controlled Channel Access (HCCA)

[0049] HCCA uses a Quality of Service (QoS)-aware centralized coordinator called the Hybrid Coordinator (HC) to initiate frame-switching sequences and allocate Transmission Opportunities (TXOPs) to itself and other Stations (STAs) for contention-free (CF) transmission of QoS data. The HC has a higher Media Access (MAC) priority than non-access point (non-AP) STAs. The HC grants STAs a polling TXOP, the duration of which is specified in the QoS(+)CF polling frame. STAs can initiate multiple frame-switching sequences during the polling TXOP period, which is limited by the TXOP duration.

[0050] When it is determined that the wireless medium (WM) is idle at the transmission (Tx) PCF inter-frame space (PIFS) slot boundary, the HC may access the wireless medium (WM) to begin the controlled access phase (CAP). The HC shall send the first frame of either the QoS(+)CF polling or any permitted frame exchange sequence, the duration of which is set to cover either the polling TXOP or the HCCA TXOP, respectively.

[0051] CAP should not span the Target Beacon Transmission Time (TBTT) measured in Units of Time (TU). The occurrence of TBTT signifies the end of CAP, after which the normal channel access procedure (EDCA or HCCA) resumes. If it is determined that the WM is idle at the TxPIF slot boundary after the HCCA TXOP, then the HC can sense the channel and reclaim it. CAP ends when the HC fails to reclaim the channel at the TxPIFS slot boundary after the HCCA TXOP.

[0052] Figure 1 depicts the Controlled Access Phase (CAP), illustrating HCCA TXOP and EDCA TXOP within the CAP, as well as access performed by legacy STAs using the Distributed Coordination Function (DCF). The figure shows the Delivery Traffic Indication Message (DTIM), whose time period value is a number used to determine the frequency at which the beacon frame contains the DTIM; this number is included in each beacon frame. A beacon is seen at the beginning of each DTIM. As shown, during the CAP or HCCA TXOP, or EDCA TXOP period, the HC can poll the QoS STA during the EDCA TXOP. The CAP includes not only the HCCA TXOP but also portions of the EDCA TXOP.

[0053] 1.3. Types of TXOP

[0054] Enhanced Distributed Channel Access (EDCA) TXOP is a TXOP obtained using the Arbitrated Interframe Space (AIFS), a method of prioritizing one Access Class (AC) over others. The length of the EDCA Function (EDCAF) TXOP is specified in the beacon frame.

[0055] HCCA TXOP is a TXOP obtained using PIFS.

[0056] The polling TXOP is the result of the HCCA TXOP obtained from the QoS(+)CF polling from the HC. The length of the polling TXOP is specified in the QoS(+)CF polling frame.

[0057] Figure 2 illustrates an example of a polling TXOP. After gaining channel access, the HC polls the QoSSTAs in turn via the QoS(+)CF. Non-AP STAs that receive the QoS(+)CF poll should respond within the SIFS, regardless of the NAV setting.

[0058] If the polling QoS STA has no queued traffic to send or if the MPDU to be sent is too long within the specified TXOP limit, the QoS STA will send a QoS(+) empty frame to indicate the corresponding queue size for the HC used to reallocate the TXOP. Within a polled TXOP, the unused portion of the TXOP should not be used by the STA and can be reallocated by the HC. As shown, the polled TXOP is protected by the NAV set by the duration field of the QoS(+)CF polling frame. All transmissions within a polled TXOP, including response frames, are considered part of the TXOP. Based on the polled TXOP limit, all decisions regarding which MAC Service Data Units (MSDUs), A-MSDUs, and / or MAC Management Protocol Data Units (MMPDUs) are sent during any given TXOP are made by the STA maintaining the TXOP.

[0059] 1.4. Acceptance control at HC

[0060] Admission control at the HC provides a guarantee of the amount of time a STA can access the channel. The Hybrid Coordinator (HC) manages admission control in the network.

[0061] Contention-based admission control is used, where the AP uses the ACM (Forced Admission Control) subfield advertised in the EDCA parameter set element to indicate whether each AC requires admission control. The ACM subfield should be static for the duration of the Basic Service Set (BSS) lifetime. The STA should send an ADD Traffic Flow (ADDTS) request frame to the HC to request admission of traffic in any direction for the AC that requires admission control.

[0062] The ADDTS request frame should include the user priority (UP) associated with the traffic and should indicate the EDCA as an access policy.

[0063] At non-AP STAs, each EDCA function (EDCAF) should maintain two MAC variables: the intermediate time allowed by the AP, `admitted_time`, and the amount of time used, named `used_time`. After negotiating with the AP via ADDTS request and response frame exchanges, the STA should calculate `admitted_time` for the specified EDCAF. The STA updates the value of `used_time` at specific times, such as after each successful or unsuccessful frame exchange.

[0064] If the used_time value reaches or exceeds the admitted_time value, the corresponding EDCAF will no longer use the EDCA parameters specified in the QoS parameter set element for that AC to send QoS data frames or QoS empty frames.

[0065] However, if those ACs do not require admission control, then the STA can choose to temporarily replace the EDCA parameters of the EDCAF with those parameters specified for the lower priority ACs.

[0066] 1.5. Controlled Access Admission Control

[0067] The Hybrid Coordinator (HC) is responsible for granting or denying polling services to admitted TSs based on the associated TSPEC. Polling services for admitted TSs provide "guaranteed channel access" from the scheduler to meet their QoS requirements. If a TS is admitted by the HC, the scheduler will provide service to the STA during a Service Period (SP), which begins at fixed time intervals. The AP should schedule the transports in the HCCA TXOP and communicate the service schedule to the STA. The AP can subsequently update the service schedule as long as it meets the TSPEC requirements. The HC can update the service schedule at any time by sending a scheduling element in the scheduling frame. The updated schedule takes effect when the HC receives the Ack frame of the scheduling frame.

[0068] 1.6. QoS(+) CF Polling Frame

[0069] Figure 3 illustrates the QoS(+)CF polling frame format with the following fields. The frame control field specifies the protocol version, type, subtype, and corresponding frame control information. A QoS(+)CF polling frame refers to all four QoS data subtypes with CF polling: QoS CF polling frame, subtype 1110; QoS CF-Ack+CF polling frame, subtype 1111; QoS data+CF polling frame, subtype 1010; and QoS data+CF-Ack+CF polling frame, subtype 1011.

[0070] Within a data frame containing QoS CF polling, the duration / ID field value is set to one of the following: (a) if the TXOP limit is non-zero, then one SIFS plus the TXOP limit, or (b) if the TXOP limit is 0, then the time required to transmit an MPDU of nominal MSDU size and the associated Ack frame plus two SIFS.

[0071] The address 1 field identifies the intended recipient of the frame; the address 2 field identifies the sender of the frame.

[0072] The sequence control field specifies the sequence number and fragment number, which are not present in the control frame. The QoS control field identifies the TC or TS to which the frame belongs, as well as various other QoS-related, A-MSDU-related, and mesh-related information about the frame that varies depending on the frame type, subtype, and transmission STA type.

[0073] The HT Control field indicates HT control information for HT variants and VHT variants. The Frame Body field contains information specific to each frame type and subtype. The FCS field contains a 32-bit Cyclic Redundancy Check (CRC). The FCS field value is calculated over all fields in the MAC header and frame body.

[0074] 1.7. TSPEC Elements

[0075] Figure 4 illustrates the Flow Specification (TSPEC) elements used in admission control in parameterized QoS. This provides informational elements for management frames (e.g., ADDTS request / response, ADDTS reservation request, DMS request / response, etc.). It also defines the characteristics of the traffic flow and QoS expectations.

[0076] The main parameters of TSPEC include the following. The Delay Bound field specifies the maximum amount of time (in microseconds) allowed to transmit an MSDU or A-MSDU belonging to a TS in this TSPEC. Service Start Time (µs): Indicates the time when a STA first expects to be ready to send frames and when STAs in power-saving (PS) mode need to wake up to receive these frames.

[0077] The minimum service interval specifies the minimum interval (in microseconds) between the start of two consecutive service points (SPs).

[0078] The Maximum Service Interval field works as follows. When the TSPEC element is used to admit HCCA flows, it specifies the maximum interval, in microseconds, between the start of two consecutive SPs. If the TSPEC element is intended for EDCA admission control, then the Maximum Service Interval field indicates a latency limit that restricts the number of aggregations (A-MSDU or A-MPDU) used to prevent excessive latency.

[0079] The Inactivity Interval field specifies, in microseconds, the minimum amount of time, which can elapse before the MAC entity at the HC deletes the TS if no MPDU belonging to the TS arrives or is transmitted.

[0080] The Suspension Interval field specifies, in microseconds, the minimum amount of time, in microseconds, that can elapse before continuous QoS (+) CF polling for this TS ceases if an MSDU belonging to this TS has not arrived or been transmitted. Certain values, such as 4 294967 295 (=2^32-1), disable the Suspension Interval, indicating that polling of the TS will not be interrupted due to inactivity.

[0081] The Service Start Time field specifies the time, in microseconds, when the first scheduled SP begins. The Service Start Time indicates to the AP that the STA first anticipates being ready to send frames and, for power saving (e.g., in the M101-Wi-Fi SiP module), the time the STA needs to wake up to receive frames. If the APSD and scheduling subfields are 0, then this field is also set to 0 (unspecified).

[0082] The Delay Bound field specifies the maximum amount of time, in microseconds, that is allowed to transmit an MSDU or A-MSDU belonging to a TS in this TSPEC element. It is measured between the time when the first MSDU, which marks an MSDU or constitutes an A-MSDU, arrives at the local MAC sublayer in the local MAC SAP and the time when the successful transmission or retransmission of the MSDU or A-MSDU to the destination is completed.

[0083] The completion of an MSDU or A-MSDU transmission includes the transmission time of the associated acknowledgment frame, if any.

[0084] The Medium Time field contains the amount of time accepted for access to the medium, in units of 32 µs / s. This field is reserved in the ADDTS request frame and set by the HC in the ADDTS response frame. This field is not used for controlled channel access.

[0085] Figure 5 depicts the subfields within the TS information field shown in Figure 4.

[0086] 2. Motivation and Problems

[0087] One of the primary motivations for this disclosure is to prevent IDC interference issues on the soft AP side. Typically, soft AP MLDs are designed to communicate with legacy STAs only on the basic link to prevent such interference.

[0088] This rule degrades the quality of service (QoS) of legacy STAs by severely limiting / reducing their channel resources. This degradation increases latency and reduces throughput, thus significantly impacting the performance of legacy STAs, especially RTAs.

[0089] If the base link is a 2.4GHz and 5GHz link, and the conditional link is a 6GHz link, the following problem arises. Legacy STAs that support 2.4GHz, 5GHz, and 6GHz links (e.g., HE STAs) will waste the advantages of using the 6GHz channel, which has a much wider bandwidth and a much lower client density than the base link.

[0090] If the underlying link is a 2.4GHz and 6GHz link and the conditional link is a 5GHz link, the following problems will occur: Legacy STAs that only support the 5GHz channel (e.g., VHT STAs) will be completely inoperable. Legacy STAs that support both 2.4GHz and 5GHz channels (e.g., HT STAs) will only operate at 2.4GHz, thus wasting all channel resources of the 5GHz channel.

[0091] In summary, allowing legacy devices to use only basic links severely limits their options. Therefore, this disclosure discusses systems and methods that enable all legacy STAs (HT, VHT, and HE) to operate on conditional links. Legacy devices can connect to conditional links via active or passive scanning. Legacy STAs are able to establish link connections on conditional links. The scheduler should not prevent legacy STAs from using conditional links unless IDC interference issues are introduced at the soft AP MLD.

[0092] 3. Hardware Implementation Examples

[0093] The ability to enable legacy (non-EHT) stations to operate on conditional links of soft AP MLDs can be implemented in various 802.11 hardware configurations, as shown below by way of example rather than limitation.

[0094] 3.1. Station Hardware Configuration

[0095] Figure 6 An example embodiment 10 of STA hardware configured to execute the protocols of this disclosure is illustrated. An external I / O connection 14 is preferably coupled to an internal bus 16 of a circuit system 12, on which a CPU 18 and a memory (e.g., RAM) 20 are connected for executing one or more programs that implement the communication protocol. The host machine houses at least one modem 22 to support communication coupled to at least one RF module 24, 28, each RF module being connected to one or more antennas 29, 26a, 26b, 26c to 26n. RF modules having multiple antennas (e.g., antenna arrays) allow beamforming to be performed during transmission and reception. In this way, the STA can transmit signals using multiple sets of beam patterns.

[0096] Bus 14 allows various devices to be connected to the CPU, such as sensors, actuators, etc. Instructions from memory 20 are executed on processor 18 to execute a program that implements the communication protocol. This program is executed to allow the STA to perform the functions of an access point (AP) station or a regular station (non-AP STA). It should also be recognized that the programming is configured to operate in different modes (TXOP holder, TXOP sharing participant, source, intermediate, destination, first AP, other APs, station associated with the first AP, station associated with other APs, coordinator, coordinated party, AP in OBSS, STA in OBSS, etc.) depending on its role in the current communication context.

[0097] Therefore, the STA HW is shown as configured with at least one modem and associated RF circuitry for providing communication in at least one frequency band. This disclosure is primarily directed to the sub-6 GHz band.

[0098] It should be recognized that this disclosure can be configured with multiple modems 22, each coupled to any number of RF circuits. Generally, using a larger number of RF circuits results in a wider coverage area in the antenna beam direction. It should be recognized that the number of RF circuits and antennas used is determined by the hardware constraints of the specific device. When a STA determines that it does not need to communicate with neighboring STAs, a portion of the RF circuit system and antennas can be disabled. In at least one embodiment, the RF circuit system includes a frequency converter, an array antenna controller, etc., and is connected to multiple antennas that are controlled to perform beamforming for transmission and reception. In this way, a STA can use multiple sets of beam patterns to transmit signals, each beam pattern direction being considered an antenna sector.

[0099] In addition, it should be noted that multiple instances of the station hardware shown in the figure can be combined into a multi-link device (MLD), which typically has a processor and memory for coordinating activities, and each STA within the MLD does not always require a separate CPU and memory.

[0100] Figure 7 Example embodiment 40 of a multi-link device (MLD) hardware configuration is illustrated. A soft AP MLD is an MLD consisting of one or more auxiliary STAs that operate as APs. The soft AP MLD should support multiple radio operations on 2.4 GHz, 5 GHz, and 6 GHz. Among the multiple radio devices, the basic link set is a pair of links that satisfy the synchronous transmit and receive (STR) mode, for example, a basic link set (2.4 GHz and 5 GHz) or a basic link set (2.4 GHz and 6 GHz).

[0101] A conditional link is a link that forms an asynchronous transmit and receive (NSTR) link pair with some basic links. For example, when 5GHz is the basic link, these link pairs may include a 6GHz link as the conditional link corresponding to the 5GHz link; when 6GHz is the basic link, the 5GHz link is the conditional link corresponding to the 6GHz link. Soft APs are used in different scenarios, including Wi-Fi hotspots and data connection sharing (tethering).

[0102] Multiple STAs are attached to an MLD, each operating on a link at a different frequency. The MLD has external I / O access to the application, which connects to an MLD management entity 48 with a CPU 62 and memory (e.g., RAM) 64 to allow the execution of one or more programs that implement the communication protocol at the MLD level. The MLD can assign tasks to each attached station it is connected to, for example, STA 1 42, STA 2 44 up to STA N 46, collect information from them, and share information among the attached STAs.

[0103] In at least one embodiment, each STA of the MLD has its own CPU 50 and memory (RAM) 52, which are coupled to at least one modem 54 via a bus 58. The modem 54 is connected to at least one RF circuit 56 having one or more antennas. In this example, the RF circuit has multiple antennas 60a, 60b, 60c to 60n, such as in an antenna array. The modem, in conjunction with the RF circuit and the associated antenna(s), transmits / receives data frames with adjacent STAs. In at least one embodiment, the RF module includes a frequency converter, an array antenna controller, and other circuitry for interfacing with its antennas.

[0104] It should be recognized that each STA in an MLD does not necessarily require its own processor and memory, as STAs may share resources with each other and / or with the MLD management entity, depending on the specific MLD implementation. It should also be recognized that the MLD diagrams above are given as examples and not as limitations, and this disclosure can be used with a wide range of MLD implementations.

[0105] 4. Network Topology

[0106] Figure 8 An example of a typical multi-link connected network topology 70 is illustrated. A soft AP MLDx 72 is shown connected to a legacy station 74 and a non-AP STA MLDy 76 via multiple wireless links.

[0107] Soft AP MLDs (EHT devices) have an identifier (ID) represented by "x", while any non-AP MLD (EHT device) is represented by an MLD ID represented by "y", and any legacy STA (non-EHT device) is represented by IDs such as "x, y, and z" for legacy systems (LS). In the example, soft AP MLD x has three affiliated AP stations, represented as APx_1, APx_2, and APx_3. Non-AP MLD y has three affiliated non-AP stations, represented as STAy_1, STAy_2, and STAy_3. APx_1, STAy_1, and LSx operate on link 1 (L1). APx_2, STAy_2, and LSy operate on link 2 (L2), while APx_3, STAy_3, and LSz operate on link 3 (L3).

[0108] Figure 9 Example 90 illustrating a network topology is illustrated for discussion purposes and not as a limitation. Soft AP MLDx 92 and non-AP MLDx 94 operate on 5GHz 104 and 6GHz 106 links. LSx 100 and LSy 102 operate only on the 5GHz link. LSm 96 and LSn 98 operate only on the 6GHz link 106. Since the 2.4GHz link is a fundamental link isolated from the 5GHz or 6GHz links, such as one unaffected by IDC interference, the following discussion will not include consideration of the 2.4GHz link.

[0109] 5. Enable legacy STAs on the conditional link of the soft AP MLD.

[0110] 5.1. Solution 1: Cooperative HCCA scheduling for NSTR on basic and conditional links

[0111] Figure 10A and Figure 10B An example embodiment 110 of cooperative HCCA scheduling for NSTR on base link 111a and condition link 111b is illustrated.

[0112] The APs on the condition link and the basic link have the same SME and are configured in this disclosure to: (1) cooperate with each other to handle simultaneous EDCA TXOPs and HCCA TXOPs on the basic link and the condition link, and (2) schedule and allocate synchronized UL or DL ​​HCCA TXOPs on both links.

[0113] Admission control will be applied to both links. Initial TS establishment and negotiation should primarily take place during the EDCA TXOP (as shown in Example 1-1), and the admission access policy should be HCCA on both the base link and the condition link. MLDs listening on the base link and the condition link can perform EDCA access during the EDCA TXOP on both links.

[0114] The associated AP of the soft AP MLD should schedule synchronized HCCA TXOP 113, 126 on both links based on the SP information obtained from the TS establishment, including at least one of the following fields: average data rate, nominal MSDU size, minimum PHY rate, remaining bandwidth tolerance, maximum service interval and delay boundary, and other desired fields.

[0115] The auxiliary APs of the soft AP MLD obtain information from the TID subfield and QoS control subfield of the received QoS data frames of all MSDUs, such as the TID, the queued traffic of the STA corresponding to a specific TID, or the next TXOP duration request for traffic belonging to a specific TID. If the request belongs to the TS, then the AP can reallocate the TXOP.

[0116] If a flow is added or dropped, the AP should reallocate the HCCA TXOP. The service interval (SI) of different admitted TSs is not necessarily the same. The AP should schedule the TXOP accordingly. There may be multiple frame exchange sequences within an HCCA TXOP, which is limited by the TXOP duration. As PPDUs, data exchange on the basic link and conditional link should be aligned at both start and end times. The diagram depicts beacons 112a and 112b followed by UL polling TXOPs 114a and 114b, DL HCCA TXOPs 116a and 116b, and HCCA TXOPs until the UL polling TXOPs 118a and 118b at the end of the HCCA TXOP period. A PPDU is a physical layer protocol data unit in the protocol and contains a preamble and a data field. It will be noted that each of these TXOPs is aligned between the basic link and conditional link at both start and end times. This is also... Figure 10B The process continues after another set of beacons 124a and 124b, with HCCA TXOP 126 being an example of DL HCCA TXOP 128a and 128b until UL polls TXOP 130a and 130b.

[0117] Soft AP MLDs, non-AP MLDs, and legacy STAs can use any type of padding to align the end time of transmitted PPDUs. Scheduling algorithms between two links are not within the scope of this proposal. PS STAs wake up at DTIM to receive beacons and should acquire some information, such as QoS and admission information.

[0118] The figure also illustrates the presence of EDCA TXOP periods 119 and 131. Figure 10A The diagram shows EDCA TXOP 120a with CAP 122a and EDCA TXOP 120b with optional CAP 122, illustrated near the end of the diagram. Figure 10B The image shows EDCA TXOP 132a and 132b with CAP 134a and 134b, which then send out another set of beacons 136a and 136b.

[0119] For this solution, access restrictions should apply to both the basic link and the conditional link. Therefore, on both links: the beacon frame should specify ACM (Forced Admission Control) = 1 for all ACs. The TS establishment procedure should be performed as described in Example 1-1. During admission control, soft APs on both the basic and conditional links should specify the access policy as HCCA with an ADDTS response frame by setting the access policy subfield in the TSPEC element, thus specifying HCCA as the access method to be used for the TS. Non-APSTA acceptance admission rules should enforce the channel access policy as HCCA.

[0120] Figure 11 and Figures 12A to 12B Example embodiments of admission control 150 and 190 are illustrated. Admission control via frame switching of ADDTS requests and responses can be performed on all legacy devices based on non-triggered TXOPs (successful transmission alone will not cause or suffer from any errors caused by IDC interference), such as... Figure 11 As seen, or for HE devices, this is executed via trigger-based MU cascading TXOP, such as Figures 12A to 12B As seen in the text.

[0121] exist Figure 11 The example TS establishment 150 is shown via a non-triggered TXOP. Interactions between soft APx_2 152 and LSx 100 on the base link and soft APx_3 154 and LSm 96 on the conditional link are shown. Backoff (BO) 156 is performed on the base link, where LSx acquires the base link and performs ADDTS frame exchange with soft APx_2 by transmitting an ADDTS request 158 ​​and receiving an ADDTS response 162, which is processed according to cases B-3 through B-6 of Example 1-2, as follows. Figure 15As seen in the diagram. While LSx is being transmitted to soft APx_2 on the basic link, the data 160 seen as UL PPDU can optionally be transmitted from LSM to soft APx_3 on another link (e.g., a conditional link), which does not cause IDC interference on the basic link. Another ADDTS request 166 and response 170 are shown as occurring on the conditional link after BO 164, while the basic link can be idle 168.

[0122] The initial TS establishment sequence for ADDTS request and response frame exchange is based on EDCA access, and frame exchange may fail, as shown in the figure (e.g., Figure 15 B-3, B-5 ​​and B-7 and Figure 16 )

[0123] After the initial TS establishment, the exchange of ADDTS request and response frames, such as updating TS establishment / negotiation, can use HCCA TXOP, which does not follow the rules of... Figure 15 and Figure 16 The process seen is based on cases B-3 to B-6 of Example 1-2.

[0124] exist Figure 12A and Figure 12B The diagram shows 190 established via TS cascading based on triggered TXOPs. The illustration shows a soft AP MLDx 192 with APx_1 associated with basic link L1 194, APx_2 associated with basic link L2 196, and APx_3 associated with conditional link L3 198. Basic link L1 is not used in this diagram.

[0125] exist Figure 12A In the middle, APx_2 on the basic link L2 begins backoff (BO) 202, while Figure 12B The conditional link L3 is in the idle 200 state. When BO 202 counts down to zero, APx_2 and APx_3 simultaneously send trigger frames (TF) 206 and 208 on L2 and L3 respectively to initiate simultaneous UL / DL cascade TXOP 204 on L2 and L3, which is used for multi-user (MU) 210 cascade sequence.

[0126] exist Figure 12A In this example, APx_2 receives UL MU data 212 as a response to TF frame 206 from some unicast RUs, along with one or more random access RUs (RA-RUs) that can also be allocated in TF 206 to receive UL PPDUs. However, in this example, it does not show any STAs using RA-RU 212.

[0127] exist Figure 12BIn this configuration, APx_3 receives UL DATA from one unicast RU as a response to TF 208, and receives two ADDTS request frames from two other unicast RUs 214. Another RA-RU 214 is reserved and is not used by any STA on L3.

[0128] Upon receiving a UL DATA or ADDTS request frame, APx_2 and APx_3 respond with acknowledgments in their respective unicast RUs (one or more). Along with BA or ACK, the AP can transmit DL DATA and / or trigger (TR) frames in the DL concatenation sequence, such as... Figure 12A 216, 224, 232 in the middle Figure 12B As shown in 218, 226, and 234, APx_2 and APx_3 can use RA-RU frequency slots to transmit some DL DATA and / or TR frames in the DL concatenation sequence, such as... Figure 12A 216 and 224 in the middle and Figure 12B As shown in 218 and 226.

[0129] After receiving a TR on one or more allocated unicast RUs, if the receiver STA has already buffered DATA and completed TS establishment, then the receiver STA can respond with UL DATA in the UL concatenation sequence, such as... Figure 12A 220, 228 and Figure 12B As shown in 222 and 230. Otherwise, the receiver may not respond in the UL cascade sequence (indicated as NONE), as... Figure 12B As shown in 222, the RA-RU is reserved for random access based on (OFDMA) (UORA) in the UL cascade sequence, as... Figure 12A 220, 228 and Figure 12B As shown in 222 and 230.

[0130] exist Figure 12B In this context, after APx_3 responds with ACK 218 to ADDTS request frame 214 on one or more unicast RUs, it also responds with ADDTS response frame 226 on the same RU(s). Along with this, APx_3 can transmit DL DATA and / or trigger (TR) frames in the DL concatenation sequence, such as... Figure 12B As shown in 226.

[0131] As will be noted from the diagram, TS establishment is performed during TB concatenation transmission. Non-AP stations use the specific RU assigned by the AP to transmit ADDTS request frames and receive ADDTS response frames. If the ADDTS response frame cannot be transmitted in the current TXOP, it can be transmitted in the next TXOP. TS establishment can also be performed during TB UL-only transmissions. In this case, the ADDTS response frame should be aligned with the ACK / BA frames transmitted on one or more other RUs.

[0132] 5.1.1. Solution 1-2: Tx and Rx between soft AP and non-AP MLD in EDCA TXOP

[0133] Figure 13 An example embodiment 250 of the second solution is illustrated, showing Tx and Rx in the EDCA TXOP between a soft AP MLD and a non-AP MLD. Soft APx_2252a and soft APx_3252b are affiliated APs of the same soft AP MLD; while non-AP STAx_2254a and non-AP STAx_3254b are affiliated non-AP STAs of the same non-AP MLD.

[0134] Part A-1 258a begins after APx_2 first obtains (wins) channel access 256a on the basic link. APx_2 transmits DL PPDU 260 on the basic link, while on the conditional link, if access is available, APx_3 transmits DL PPDU synchronously with AP x_2; otherwise, it does not transmit. Then, non-AP stations simultaneously send BA 262 on both the basic and conditional links as a response to the receipt of DL DATA.

[0135] In part A-2 258b AP x_3, a 256b conditional link is acquired. If the basic link is available, then AP x_2 and AP x_3 transmit DL PPDU simultaneously, followed by BA; otherwise, they do not transmit and reset EDCA on the conditional link.

[0136] In part of the A-3 258c non-AP STA x_2, a 256c basic link is acquired. On the basic link, the non-AP STA x_2 transmits UL PPDUs. On the conditional link, if access is available, the non-AP STA x_3 synchronously transmits UL PPDUs, where BA 262 is considered a response to the UL PPDU received on each link. If access is unavailable on the conditional link, no transmission occurs on that link.

[0137] In part of A-4 258d, non-AP STAx_3 senses that the conditional link is idle and completes the BO count on the contention link. If the basic link is available, then non-AP STAx_2 and non-AP STAx_3 simultaneously transmit UL PPDUs and simultaneously receive BAs. Otherwise, they do not transmit or reset EDCAs on the conditional link.

[0138] It should be noted that access availability on conditional links can be determined by PIFS sensing, and access availability on basic links can be determined by EDCA rules.

[0139] Figure 14 Another example embodiment 290 is illustrated, where LSx 294a and LSm 294b are legacy stations operating on the basic link and conditional link, respectively, and are associated with APx_2292a and APx_3 292b, respectively. APx_2 292a and APx_3 292b are auxiliary APs of the same soft AP MLD.

[0140] The AP attached to the soft AP MLD should be able to detect whether the received PPDU comes from an EHT device or a non-EHT device (legacy device) based on the PPDU preamble. As shown in the figure, the soft AP MLD may have different responses after receiving a non-EHT PPDU.

[0141] In part B-1:298a, APx_2 has already obtained channel access 296a on the basic link and transmits DL PPDU 300; if the conditional link is available, then APx_3 synchronously transmits another DL PPDU 302, the endpoint of which is aligned with the DL PPDU 300 transmitted on the basic link. Otherwise, if the conditional link is unavailable, then APx_3 does not transmit any DL PPDU. After receiving the aligned DL PPDU on the basic link and the conditional link, LSx and LSM simultaneously respond with aligned BA 304 on the corresponding links.

[0142] In part B-2 298b, APx_3 obtains 296b conditional link access. If the basic link is available, then APx_2 and APx_3 can simultaneously transmit DL PPDU 300 (aligned), followed by their respective aligned BA 304. Otherwise, if the basic link is unavailable, then APx_3 should not transmit and EDCA is reset on the conditional link.

[0143] Figure 15Another embodiment 330 is illustrated, showing another example of legacy stations LSx 294a and LSm 294b operating on the basic link and conditional link, respectively, which are associated with APx_2 292a and APx_3 292b, respectively. APx_2 292a and APx_3 292b are auxiliary APs of the same soft AP MLD.

[0144] In part B-3 333a, LSx first acquires 332a (wins) the basic link for non-TB UL transmission, and then transmits UL PPDU 334 on the basic link LSx, which can be followed by RTS-CTS frame exchange with APx_2.

[0145] On the conditional link, if access is available and if APx_3 can align the frame switching sequence of the conditional link with the frame switching sequence of the basic link, then APx_3 should initiate a UL TB PPDU simultaneously with APx_2. Otherwise, APx_3 should not send any frames to trigger a UL PPDU, nor should it respond to any received UL PPDU.

[0146] Due to concurrent DL TX on the base link such as BA 336, any UL PPDU on the condition link that is out of sync with the base link may suffer IDC interference at AP x_3 338.

[0147] In section B-4 333b, APx_2 first acquires the 332b base link for TB UL transmission and initiates a TB ULTXOP. A trigger frame (TF) 342, followed by a UL PPDU, can be seen being sent on both the base link and the conditional link (if available). If APx_3 cannot use the conditional link simultaneously with APx_2, then it should not send any UL PPDUs. A BA is sent in response to any UL PPDU.

[0148] In part of B-5 333c, the LSM acquires a conditional link for UL TX (332c). Because the primary link is currently idle, the LSM begins transmitting UL PPDU 340 on the conditional link. However, if APx_2 acquires the primary link and begins transmitting DLPPDU, this UL PPDU on the conditional link will not be heard by APx_3. Therefore, the UL PPDU on the conditional link appears to be in progress, and becomes subject to IDC interference while DL PPDU is transmitted on the primary link. The DLPPDU on the primary link may be an immediate response to a previously received frame or an urgent DL PPDU that needs to be transmitted immediately.

[0149] In part B-6 333d APx_3, a conditional link 332d is obtained to trigger a UL TX. Then, if the basic link is available, APx_2 and APx_3 should initiate triggers to simultaneously trigger UL PPDUs. Otherwise, APx_3 should not transmit anything and the EDCA should be reset on the conditional link.

[0150] Figure 16 Example embodiment 390 is illustrated, which shows another example of operation on basic and conditional links. Legacy stations LSx 394a and LSM 394b are considered to operate on the basic link and conditional link, respectively, and they are associated with APx_2 392a and APx_3 392b, respectively. APx_2 392a and APx_3 392b are auxiliary APs of the same soft AP MLD.

[0151] In a portion of the B-7 400 soft AP MLDx, APx_2 first acquires 396 (basic link 398) when the conditional link CCA is busy. On the basic link, APx_2 transmits DL PPDU 402, and subsequently receives BA 406. On the conditional link, APx_3 is unable to transmit DL PPDUs due to CCA busy 398, and the end of the CCA busy period cannot be detected due to DL TX interference from the basic link. Any UL PPDU 404 from LSM cannot be heard on the conditional link due to IDC interference.

[0152] It should be noted that if a soft AP MLD communicates with different non-AP STAs that may not be from the same non-AP MLD via different links, then the non-AP STAs are unaware of each other's TX / RX status. Therefore, the channel access situation is covered in B1-B7 of the previous diagram.

[0153] Figures 17A to 17E The illustration shows an example embodiment 430 of soft AP MLD communication with a legacy station (LS) during EDCA TXOP.

[0154] exist Figure 17A In the process, the soft AP MLD checks 432 to determine if it has acquired (won) access to the basic link channel. If it has acquired the basic link, then at check 434 it determines if it needs to send one or more DLPPDUs to the legacy system (LS). If it does need to send one or more DLPPDUs to the LS on the basic link, then at box 436 a check is performed to determine if the conditional link is idle. If the conditional link is idle, then at box 438, the basic link AP and the conditional link AP of the same soft AP MLD simultaneously transmit one or more DLPPDUs and maintain alignment, and then the process continues... Figure 17EThe middle part ends here.

[0155] However, if the AP at the soft AP MLD in box 432 has not yet obtained a basic link, then a move to [the specified location] is performed. Figure 17C Box 448 in the code checks whether the AP in the soft AP MLD has acquired (obtained / won) a conditional link. If no conditional link has been acquired, then a move to the conditional link is performed. Figure 17D Box 462 in the code checks whether the legacy system (LS) has acquired a basic link. If not, then a move to a new system is performed. Figure 17E Box 470 in the code checks whether the LS has already acquired a conditional link. If not, the process ends because no link has been acquired yet.

[0156] Returning to the condition when the soft AP MLD's AP has acquired (won) the condition link meets the conditions. Figure 17C The process proceeds to box 448, then moves to box 450, which checks whether the conditional link AP needs to send a DL PPDU to the legacy system (LS). If the condition is not met, the process moves to box 456, which determines whether the conditional link AP needs to trigger a ULPPDU. If this condition is not met, the process continues... Figure 17E The process ends here. Otherwise, the AP needs to trigger one or more ULPPDUs and move to check 458 to determine if the base link is idle at this time. If the base link is not idle, then move to box 454 in the diagram (discussed below). If the base link is idle, then at box 460, the base link AP and the condition link AP of the same soft APMLD trigger UL PPDUs simultaneously, and the process ends here.

[0157] Now we return to block 450, which discusses the case where the conditional link AP needs to send a DL PPDU to the LS, and proceeds to block 452, which determines whether the basic link is idle. If the basic link is idle, then proceeds to move to... Figure 17A In box 438, the base link AP and condition link AP of the same soft AP MLD transmit DL PPDU simultaneously before the process ends. Otherwise, if it is determined at box 452 that the base link is not idle, then it is determined at box 454 that the condition link AP is not allowed to transmit DL / UL PPDU, and the process ends.

[0158] Now let's go back to the discussion. Figure 17A Box 434 in the diagram addresses the situation where the condition for the basic link AP to send a DL PPDU to the LS is not met, and a move to the LS is performed. Figure 17B Box 440 in the code performs a check to determine if the basic link AP needs to trigger a UL PPDU. If the condition is not met, then execution is performed in... Figure 17EThe process ends there. Otherwise, proceed to box 442, which determines whether the conditional link is idle. If the conditional link is not idle, then at box 446 it is determined that only the basic link AP should perform the transmission and the process ends. However, if the conditional link is idle at box 442, then at box 444, both the basic link AP and the conditional link AP transmit the UL PPDU simultaneously before the process ends.

[0159] Returning if the conditional link is not idle Figure 17A Box 436 in the middle, then execute to reach Figure 17B Box 446 in the diagram determines that only the basic link AP should perform the transmission and the process ends.

[0160] Now return to Figure 17D In block 462, for the case where the LS has acquired the basic link and performed a move to block 464, it checks whether the conditional link AP can be scheduled for a simultaneous UL TXOP with the basic link. If the condition is met, then at block 466, the conditional link AP and the basic link AP are scheduled for a simultaneous UL TXOP, and the process ends. Otherwise, if the condition is not met, then at block 468, the basic link AP and the LS perform a UL TXOP, but the conditional link AP should not send any PPDU, and the process ends.

[0161] Now return to Figure 17E In block 470, if the LS has already acquired a conditional link, proceed to block 472, which determines whether the basic link is available. If the basic link is available, then at block 474, the basic link AP and the conditional link AP schedule simultaneous UL TXOP transmissions, after which the process ends. Otherwise, since the basic link is unavailable, then at block 476, the conditional link AP is not allowed to send any PPDUs, and the process ends.

[0162] 5.2. Simultaneously UL / DL HCCA TXOP

[0163] Simultaneously scheduled UL / DL TXOPs can be applied to: (a) legacy STAs, (b) (same or different) non-AP MLDs and their affiliates, and (c) non-AP MLDs and legacy STAs on the basic link or conditional link.

[0164] Figure 18 An example embodiment 510 of simultaneously scheduled UL / DL TXOPs is illustrated. If both links are idle at the TxPIFS time slot boundary, then two APs attached to the same soft AP MLD simultaneously acquire the basic link 512 and the conditional link 514. All stations comply with the HCF NAV rules, and each frame transmitted under HCF includes an NAV duration value.

[0165] If an AP has no more STAs to poll and no more data, management, block acknowledgment request (BACK) or block acknowledgment (BACK) frames to send, it can reset the NAV of all QoS STAs in the BSS by sending a QoS CF polling frame, where the RA matches its own MAC address and the duration / ID field is set to 0.

[0166] When a STA receives a frame addressed to it and requires acknowledgment, it should respond with an Ack or QoS+CF-ACK frame, regardless of its NAV. Non-AP STAs should accept polled TXOPs by initiating a frame exchange sequence, regardless of their NAV.

[0167] for Figure 18 In the UL TXOP, the auxiliary APs of the soft AP MLD simultaneously poll non-AP stations operating on both the basic link and the conditional link by allocating the same polling TXOP duration. The polling TXOP durations 516a, 516b, 518a, 518b, 520a, 520b, 522a, and 522b on the basic link and the conditional link are scheduled based on the traffic conditions of the polling station.

[0168] Polling of non-AP stations (which are non-AP QoS STAs with their own addresses that match the address 1 field of the received QoS CF polling frames) should not exceed the polling TXOP duration and any type of padding or frame aggregation may be used to maintain PPDU end-time alignment on the basic link and conditional link.

[0169] If a polling non-AP station uses only a portion of its allocated TXOP, the receiving AP should not poll until the polling TXOP on another link is complete. Attached APs to a soft AP MLD should poll simultaneously. A polling non-AP station can transmit multiple frame-switching sequences within a given polling TXOP, which is limited by the TXOP duration.

[0170] for Figure 18 In the DL TXOP, the auxiliary AP of the soft AP MLD should simultaneously send one or more DL PPDUs to the non-AP station operating on each link by allocating the same HCCA TXOP duration. The auxiliary AP of the soft AP MLD can transmit multiple frame-switching sequences within a given polling TXOP, which is limited by the TXOP duration. The auxiliary AP of the soft AP MLD can use any type of padding to align the end time of the transmitted PPDUs.

[0171] 5.2.1. Cooperative Scheduling on HCCA TXOP for Basic Link and Conditional Link Duration

[0172] Figure 19 The illustration shows an example implementation 550 of cooperative scheduling.

[0173] In block 552, it is checked whether the APs of the same soft AP MLD have acquired (won) the basic link and the conditional link. If the condition is not met, then wait 554 occurs before a repeat check (within limits). If the condition is met, then in block 556, it is checked whether the soft AP MLD needs to send a DL PPDU. If the condition is met, then in block 558, the basic link AP and the conditional link AP simultaneously initiate DL HCCA PPDUs on the basic link and the conditional link, and the process ends. Otherwise, if the condition in block 556 is not met, then in block 560, it is checked whether the soft AP MLD needs to poll for a UL PPDU. If polling is not required, then the process ends. Otherwise, in block 562, the basic link AP and the conditional link AP simultaneously initiate UL polling TXOPs on the basic link and the conditional link, and the process ends.

[0174] 5.3. Example 1-3-1 Recovery from the absence of expected reception

[0175] Figure 20 The diagram illustrates topology 590 of Example 1-3-1 regarding the problem of recovery from unexpected reception in the case of a hidden terminal. It should be noted that the separation of 5GHz and 6GHz in the diagram only indicates frequency band separation, not spatial separation. The diagram shows a soft AP MLDy 592 operating in 5GHz 608 and 6GHz 612, along with associated APs, such as softAPy_2 and softAPy_3, respectively; a soft AP MLDx 594 operating in both 5GHz 606 and 6GHz 610, along with associated APs, such as softAPx_2 and softAPx_3, respectively; softAPy_2, softAPy_3, softAPx_2, and softAPx_3 are not shown in the diagram. A non-AP MLDx 600 operating in the 5GHz 606 and 6GHz 610 links uses associated non-AP STAs, such as non-AP STA x_2 and non-AP STAx_3, respectively. Non-AP STA x_2 and non-AP STA x_3 are not shown in this figure.

[0176] Legacy stations LSx 602 and LSy 598 are associated with one of the auxiliary APs of soft AP MLDx 594, which operates on 5 GHz. Legacy stations LSm 604 and LSn 596 are associated with one of the auxiliary APs of soft AP MLDx 594, which operates on 6 GHz. LSy and LSn are within the coverage area of ​​the auxiliary AP of soft AP MLDy, on 5 GHz and 6 GHz respectively.

[0177] This diagram illustrates an example of a collision between a QoS CF polling frame and another management frame in a hidden terminal scenario. Assume that soft APx_3 of soft AP MLDx and soft APy_3 of soft AP MLDy are operating on a 6GHz channel and cannot hear each other. A collision occurs when soft APx_3 and soft APy_3 simultaneously transmit frames to / to LSN 596. It should be noted that the interfering frame may not be transmitted to LSN; the arrows indicate frames that can be heard by a specific station but are not addressed to that station.

[0178] Figure 21 The illustration shows Example 1-3-1 of 630, which illustrates the composition of... Figure 20 This diagram illustrates an embodiment of a solution to the conflict problem caused by the hidden AP issue. The diagram depicts the interactions between soft APx_2 632 and LSy598, soft APx_3 634 and LSn 596, and soft APy_3 636 and LSn 596. It should be recognized that LSn is shown on two lines in the diagram during the communication interaction because it involves communication between hidden terminals, where one hidden terminal communicates with LSn and the other hidden terminal interferes with LSn.

[0179] To address the collision issues caused by hidden APs sending management frames on a single link (e.g., a 6GHz link), in at least one embodiment of this disclosure, a very small (compact) DL PPDU without a DATA payload is sent instead of QoS CF polling immediately at the start of TXOP, since the recovery / retransmission time on one link may be affected by the size of the UL PPDU polled on another link.

[0180] In the diagram, soft APy_3 is performing backoff 638, and soft APx_2 and soft APx_3 are similarly competing for channel access. Soft APy_3 completes its backoff countdown, and soft APx_2 and soft APx_3 sense that the channel is idle at TxPIF boundary 640, and then each of the three simultaneously acquires its respective link.

[0181] In the solution to this 1-3-1 problem, element (a) is executed, where it can be seen that if both the basic link and the conditional link are idle at the TxPIFS slot boundary, then the two APs attached to the soft AP MLDx simultaneously transmit very small (compact) DL PPDU frames 644 and 645 (e.g., RTS, empty, control, or management frames) on both links, and the duration of NAV 642 protecting the TXOP can be seen in response to the start of DL PPDU transmission. However, the soft APy_3 simultaneously transmits the full DL PPDU 648.

[0182] The condition regarding element (a) includes (a)(i) where if any AP station cannot receive CTS / ACK / BA as a response to DL PPDU 650 after SIFS 646, then it indicates a possible collision. The retransmission process should repeat this short DL PPDU transmission as in (a). Thus, we can see that soft APx_2 and soft APx_3 regain access to the channel and send short DL PPDUs 652 and 656, NAV 654 and 660, and we can see that soft APx_3 is busy at 658.

[0183] (a)(ii) If two APs receive CTS / ACK / BA as responses to DL PPDU 662 and 664 after SIFS, then they should poll 666 and 668 UL TXOP or send DL TXOP simultaneously on the basic link and the conditional link, with an updated NAV duration of 654.

[0184] (a)(iii) Two APs attached to a soft AP MLDx can limit the number of retransmissions of small DL PPDU frames on both links (in the case of soft APy_3 sending very long DL PPDUs). When the retransmission limit is met, the AP receives CTS / ACK / BA as a response to the DL PPDU after SIFS and should poll the UL TXOP or send the DL TXOP independently. If the AP does not receive CTS / ACK / BA as a response to the DL PPDU, it should not poll the UL TXOP or send the DL TXOP.

[0185] After CF polling, you can see that LSy and LSN send UL PPDU 670 and 672 to the soft AP MLD from which it receives BA 674 and 676.

[0186] Figure 22 The illustration shows example topology 690, such as 1-3-2, regarding the problem of recovery from a hidden terminal in a CFP scenario where there is no expected reception, where a collision occurs between QoS CF polling frames using HCCA. The diagram is... Figure 20The diagram also shows variants of the soft AP MLDy 592 operating in 5GHz 608 and 6GHz 612, along with associated APs, such as softAPy_2 and softAPy_3, respectively; and soft AP MLDx 594 operating in both 5GHz 606 and 6GHz 610, along with associated APs, such as softAPx_2 and softAPx_3, respectively; softAPy_2, softAPy_3, softAPx_2, and softAPx_3 are not shown in the diagram. Non-AP MLDx 600 operating in the 5GHz 606 and 6GHz 610 links uses associated non-AP STAs, such as non-AP STAx_2 and non-AP STAx_3, respectively. Non-AP STAx_2 and non-AP STAx_3 are not shown in the diagram.

[0187] Legacy stations LSx 602 and LSy 598 are associated with one of the auxiliary APs of soft AP MLDx 594, which operates on 5 GHz. Legacy stations LSm 604 and LSn 596 are associated with one of the auxiliary APs of soft AP MLDx 594, which operates on 6 GHz. LSy and LSn are within the coverage area of ​​the auxiliary AP of soft AP MLDy, on the 5 GHz and 6 GHz links, respectively.

[0188] This diagram illustrates an example of a QoS CF polling frame conflict caused by a hidden terminal issue. Soft APs MLDx and MLDy operate on 5GHz and 6GHz links respectively and cannot hear each other. A conflict occurs when the auxiliary APs of soft APx and soft APy simultaneously send QoS CF polling frames to LSN on the 6GHz link and LSY on the 5GHz link.

[0189] Figure 23 The figure illustrates Example 1-3-2 of 710, which shows an embodiment of a recovery scheme for a conflict problem caused by a hidden terminal in a CFP when initiating an HCCA TXOP. The figure depicts the interactions between soft APx_2 712 and LSy 598, soft APy_2 714 and LSy598, soft APx_3 716 and LSn 596, and soft APy_3 718 and LSn 596.

[0190] This addresses the conflict issue caused by hidden terminals sending QoS CF polling frames according to the HCCA policy. This is related to... Figure 21 It is the same as that described in element (a) of Example 1-3-1.

[0191] (a)(i) If any AP station fails to receive a CTS / ACK / BA as a response to a DL PPDU after SIFS, it indicates a potential collision. However, if it proceeds directly to step (a), a subsequent collision may occur. To avoid subsequent collisions, simultaneous recovery and / or retransmission for each soft AP MLD can begin after aSIFSTime + n * aSlotTime, where n is a random variable.

[0192] (a)(ii) This is the same process as described in (a)(ii) of, for example, 1-3-1.

[0193] The diagram shows soft APs acquiring the 720 link at the TxPIF slot boundary 722 and each sending DL PPDU 724. Since these soft APs do not receive any response to the DL PPDU, they retrace their channel access. Soft APx_2 and soft APx_3 retrace their channel access after SIFS time; soft APy_2 and soft APy_3 retrace their channel access after SIFS + 2 * SlotTime. Then, after SIFS, soft APx_2 and soft APx_3 can be seen to acquire the channel again and send short DL PPDUs 730 and 736, NAV 734 and 740, and soft APy_2 and 3APy_3 can be seen to be busy at 732 and 738. If APx_2 and APx_3 both receive CTS / ACK / BA as responses to the DL PPDUs 742 and 746 after SIFS, then they poll 748 and 750 UL TXOP. As can be seen, UL PPDUs 752 and 754 are received, and then the AP responds with the associated BAs 756 and 758.

[0194] 5.3.1. Solution 2: Adaptive round-robin scheduling of conditional links based on basic link status.

[0195] Figure 24 An example embodiment 790 of adaptive polling-based scheduling on conditional links based on basic link states is illustrated.

[0196] Stations operating on the basic link use the EDCA policy to access the channel. Legacy (non-EHT) devices access the conditional link based on the HCCA policy. EHT devices can access the conditional link via either EDCA or HEMM, i.e., a hybrid HCCA / EDCA mode. All stations comply with the HCF's NAV rules.

[0197] The APs associated with the soft AP MLD are aware of UL / DL transmissions on the primary link because they share the same Station Management Entity (SME). The APs in the soft AP MLD for the conditional link should schedule UL / DL transmissions on the conditional link based on concurrent UL / DL transmissions on the primary link.

[0198] The AP in a Soft AP MLD on a conditional link can negotiate with a non-AP legacy STA to agree on a large maximum service interval (SI) value during admission control. The AP in a Soft AP MLD can schedule the maximum SI of the admitted traffic flow (TS) to prevent being unable to serve the TS at the scheduled time due to simultaneous transmission and reception on the basic link and conditional link, or interference with the conditional link. If the next service start time meets the maximum SI value for admission on the conditional link, but one or more HCCA TXOP scheduling on the conditional link would result in asynchronous UL / DL transmissions alongside concurrent basic link transmissions, then the AP in a Soft AP MLD on the conditional link should not serve the TS.

[0199] The AP in the soft AP MLD grants the STA a polling TXOP with a duration specified in the QoS(+)CF polling frame. One or more frame exchanges may occur within the polling TXOP, and the start and end times of the frame exchange sequences on the basic link and conditional link should be aligned.

[0200] Figure 24 The illustration shows an example embodiment 790 of a STA operating on a basic link 792 accessing a channel based on an EDCA policy, where a legacy (non-EHT) device accesses a conditional link 794 using an HCCA policy. A BO 796 is visible on the basic link, and when the BO countdown reaches zero, the conditional link is sensed as idle at the TxPIF boundary 798. Therefore, EDCA ULTXOP 800 begins on the basic link, while UL polling TXOP 802 is executed on the conditional link simultaneously. A similar example can be seen: EDCA DL TXOP 804 on the basic link and simultaneous DL HCCA TXOP 806 on the conditional link. Furthermore, after the BO, EDCA DL TXOP 808 begins on the basic link, while DL HCCA TXOP 810 is on the conditional link. Then, after the BO, EDCA UL TXOP 812 begins on the basic link, while UL polling TXOP 814 is on the conditional link.

[0201] 5.4. Admission Control: Only used for conditional links with polling-based access.

[0202] For this solution, access restrictions should only apply to devices operating on the conditional link. Therefore, the following regarding conditional links is correct: The beacon frame should set (specify) ACM (Forced Admission Control) = first state (e.g., "1"), meaning true for all ACs. The TS establishment procedure should be performed as described in Example 1-1. When the AP receives an ADDTS request during admission control, it can distinguish between EHT PPDUs and non-EHT PPDUs, such as from header information.

[0203] The following applies during admission control. If an ADDTS request is received from a non-EHT device (legacy device), the soft AP on the conditional link should specify the channel access policy by sending an ADDTS response frame to the legacy device and setting the access policy subfield in the TSPEC element indicating that the admitted TS is HCCA to HCCA. If an ADDTS request is received from an EHT device, the soft AP on the conditional link should specify the channel access policy as EDCA or HEMM.

[0204] Non-AP legacy STAs and non-AP EHT devices operating on conditional links that accept admission rules should follow the access policies agreed upon during admission control.

[0205] 5.4.1. Example 2-1 UL TXOP Alignment

[0206] Figure 25 The illustration shows Example Embodiment 830, illustrating Example 2-1 UL TXOP alignment. The figure depicts the interactions between APx_2 832 and LSx 602, APx_3 834 and LSm 604, APx_2 836 and non-AP STAx_2 837, and APx_3 838 and non-AP STAx_3 839.

[0207] In section (A) of the figure, the base link AP of the soft AP MLD initiates a trigger-based UL TXOP for non-EHT devices by performing backoff 840 and sending TF 842. During TF, the APx_3 sensing condition link of the same AP MLD is idle at the TxPIF boundary and can simultaneously poll any non-EHT device on the 844 condition link. The AP can be seen receiving UL PPDUs 850 and 852 in response from the AP with BA858.

[0208] In section (B) of the figure, the non-EHT device initiates a UL TXOP on the basic link using RTS frame 860 after its BO 840. The AP responds with CTS 864, and during this time, if the channel is detected to be idle at the TxPIF boundary, the conditional link APs of the same APMLD simultaneously poll any non-EHT device on the conditional link 866. It can be seen that the AP receives UL PPDUs 872 and 874 in response to the AP with BA 858.

[0209] In section (C) of the diagram, the base link AP of the soft AP MLD initiates a UL TXOP for the EHT device using TF 846. Simultaneously with TF 846, if the channel is detected to be idle at the TxPIF boundary, the soft AP MLD AP sends a TF / QoS CF polling 848 on the conditional link. It can be seen that the AP receives UL PPDUs 854 and 856, and responds to them with BA.

[0210] In section (D) of the diagram, the EHT device on the basic link initiates a UL TXOP to the soft AP MLD using RTS frame 862 after BO 840, and the AP responds with CTS 868. Simultaneously with CTS 868, the soft AP MLD sends a TF / QoS CF poll 870 on the conditional link. It can be seen that the AP receives UL PPDU 876 and optional 878 in response from the AP with BA.

[0211] The soft AP SME should guarantee the alignment of each simultaneous UL and DL transmission. If the conditional link is busy (e.g., due to Overlapping Basic Service Set (OBSS) interference), then the conditional link AP should not send TF / polling / CTS frames on the conditional link.

[0212] 5.4.2. Example 2-2 DL TXOP Alignment

[0213] Figure 26 The illustration shows an example embodiment 930 of DL TXOP alignment in Example 2-2. As previously shown in Figure 9 The stations shown in the topology example are depicted as having interactions between APx_2 832 and LSx 100, APx_3 834 and LSm 96, APx_2 836 and non-APSTAx_2 94a, and APx_3838 and non-APSTAx_3 94b.

[0214] In section (A) of the figure, it can be seen that the base link AP of the soft AP MLD initiates a DL TXOP for non-EHT devices after BO 932. The DL TXOP is shown along with DL PPDU 934 and BA response 946. If the conditional link is available as shown in the figure, the conditional link AP of the same soft AP MLD should initiate a DL TXOP for any non-EHT device operating on the conditional link after detecting that the conditional link is idle at the TxPIF boundary, with the end time of each DL PPDU 936 aligned by segmentation or padding 944.

[0215] In section (B) of this figure, the base link AP of the soft AP MLD initiates a DLTXOP for the EHT device after BO 932. The DL TXOP is shown along with DL PPDU 938 and BA response 946. If the conditional link is available, as illustrated here, the conditional link AP of the same soft AP MLD can send a concurrent DL PPDU 940 after sensing that the conditional link is idle at the TxPIF boundary. If the conditional link AP has no DL PPDU to send, then the DL PPDU can be a single DLNULL PPDU, where the NAV is set to concurrent DL TXOP on the base link. If the conditional link AP has a DL PPDU to send after sending a DL NULL PPDU, then it can send DL PPDU 942 after sensing that the conditional link is idle at the TxPIF boundary on the conditional link, where the end of the PPDU is aligned with the DL PPDU from the base link. This shows that a gap appears between DL PPDUs, where the non-AP STAx_3 performs CCA sensing, acquires the channel, and transmits another DL PPDU 942 to align with the DL PPDU of the base link during the PIFS duration.

[0216] In (A) and (B), if the conditional link is unavailable, then the AP on the conditional link should not send DL PPDU on the conditional link.

[0217] Figures 27A to 27D The illustration shows an example embodiment 970 of TXOP scheduling on a conditional link based on the basic link state. During this scheduled TXOP process, check 972 determines whether the conditional link is idle. If it is not idle, then the process continues... Figure 27DThe process ends in [section 974]. Otherwise, block 974 checks whether the AP of the soft AP MLD has acquired the basic link and is initiating a TBUL TXOP. If the condition is met, then at block 976, the AP of the same soft AP MLD sends a trigger or polling frame on the conditional link, while simultaneously sending a trigger frame on the basic link. Execution proceeds to block 978, where the polling UP TXOP is set to the same TXOP duration as the concurrent UL TXOP on the basic link.

[0218] Execute move to Figure 27C In block 994, the polling STA on the conditional link checks whether it has a ULPPDU to transmit. If a UL PPDU exists, then each UL PPDU on the conditional link is transmitted at block 996 to align with the UL PPDU on the base link, and in block 998, the AP of the soft AP MLD responds with ACK / BA on both the base link and the conditional link upon receiving the UL PPDU, after which the process ends.

[0219] Now, returning to box 994, if the polled STA has no UL PPDU to transmit, then at box 1000, the UL PPDU is sent only on the basic link, and STAs on the conditional link are not allowed to access the conditional link until the NAV expires. Then, at box 1002, the AP of the soft AP MLD receives the UL PPDU on the basic link and responds with ACK / BA, after which the process ends.

[0220] return Figure 27A Block 974 addresses the case where the soft AP MLD has not acquired the basic link for initiating the TB UL TXOP, and then proceeds to block 980. Block 980 checks whether the AP of the soft AP MLD has received a Ready to Transmit (RTS) from the non-AP STA. If the condition is met, then at block 982, the AP responds by sending a Clear Transmit (CTS). Subsequently, in block 984, the AP of the same soft AP MLD sends a polling frame on the conditional link and a CTS frame on the basic link, and proceeds to block 978, as previously described.

[0221] Now return to box 980, for the case where the soft AP MLD does not receive RTS from the non-AP STA, and then perform a move to... Figure 27B Box 986. In box 986, a check is performed to determine if the soft AP MLD has acquired a basic link and is initiating a DL TXOP. If the conditions are not met, then the process proceeds... Figure 27DEnd of section. Otherwise, since the AP of the soft AP MLD has acquired the basic link and is initiating a DL TXOP, a check is performed in block 988 to determine whether the AP of the same soft AP MLD has a DL PPDU to send to any non-AP STA on the conditional link.

[0222] If the conditions are met, then at box 990, the conditional link AP initiates a DL TXOP, the duration of which is the same as the concurrent DL TXOP on the basic link, and performs the move. Figure 27D Box 1004. In box 1004, padding is applied to align the end time of each DL PPDU on the conditional link with that on the basic link. Then, at box 1006, the AP of the soft AP MLD should simultaneously receive ACK / BA from the non-AP STA as a response to the DL PPDU, after which the process ends.

[0223] Now return to Figure 27B Block 988 addresses the case where the AP in the same soft AP MLD has no DL PPDU to send on the conditional link to any non-AP STA, therefore execution proceeds to block 992, where the AP for the conditional link can send a DL NULL PPDU with the same NAV duration as the concurrent DL TXOP duration on the basic link, after which execution moves to block 992. Figure 27D The box is 1008.

[0224] Decision block 1008 checks whether the conditional link AP has a DL PPDU to send after the DL NULL PPDU and before the concurrent DL PPDU ends on the basic link. If the condition is not met, then at block 1012, the soft AP MLD receives an ACK / BA as a response to the DL PPDU on the basic link, and the process ends.

[0225] Otherwise, if the condition in box 1008 is met, then at box 1010, the condition link AP sends a DL PPDU whose end time is aligned with the concurrent DL PPDU on the basic link, and the process ends.

[0226] 6. Summary

[0227] Legacy (non-EHT) devices are capable of establishing link connections on conditional links. The scheduler should not prevent legacy STAs from using conditional links unless it will cause IDC interference issues at the soft AP MLD.

[0228] 6.1. Method 1: Cooperative HCCA scheduling for simultaneous transmission and reception on basic and conditional links

[0229] (1) APs on the condition link and the basic link are attached to the same soft AP MLD, have the same SME, and should cooperate with each other to handle simultaneous EDCA TXOP and HCCA TXOP on the basic link and the condition link.

[0230] (2) Admission control applies to both links. TS establishment / negotiation should primarily take place in EDCA TXOP, and HCCATXOP scheduling should be based on the SP information for admission obtained from TS establishment. The access policy for admission should be HCCA on both the basic link and the conditional link.

[0231] (3) APs attached to the same soft AP MLD should schedule and allocate synchronized UL or DL ​​TXOPs on the basic link and conditional link during the HCCA TXOP period. (a) Attached APs of the soft AP MLD may schedule synchronized HCCA TXOPs based on SP information obtained from the TS establishment, such as average data rate, nominal MSDU size, minimum PHY rate, remaining bandwidth tolerance, and at least one of maximum service interval and delay limits. (b) Attached APs of the soft AP MLD obtain information from the TID subfield and QoS control subfield of the received QoS data frames for all MSDUs, such as the TID, queued traffic of the STA corresponding to a specific TID, or the next TXOP duration request for traffic belonging to a specific TID. If the request belongs to the TS, the AP may reallocate the TXOP.

[0232] (4) If a flow is added or dropped, the scheduler should reallocate the HCCA TXOP.

[0233] (5) The service interval (SI) of different admitted TSs may not be the same. The AP should schedule TXOP accordingly.

[0234] (6) Multiple frame exchange sequences are allowed within an HCCA TXOP, which is limited by the TXOP duration. PPDUs on the basic link and conditional link should be aligned at the start and end times.

[0235] (7) Soft AP MLD, non-AP MLD and legacy STA can use any type of padding to align the end time of the transmitted PPDU.

[0236] (8) Simultaneously scheduled UL / DL HCCA TXOP can be applied to a) legacy STAs, b) (same or different) non-AP MLDs, and c) non-AP MLDs and legacy STAs on the basic link and conditional link.

[0237] (9) If both links are idle at the TxPIFS time slot boundary, then the two APs attached to the soft AP MLD will simultaneously obtain the basic link and the conditional link.

[0238] (10) All stations adhere to the HCF NAV rules, and each frame transmitted under HCF includes an NAV duration value. (a) If the AP has no more STAs to poll and no more data, management, block acknowledgment requests, or block acknowledgment frames to send, it can reset the NAV of all QoS STAs in the BSS by sending a QoS CF polling frame, where the RA matches its own MAC address and the duration / ID field is set to 0. (b) When a STA receives a frame addressed to it and requests acknowledgment, it should respond with an Ack or QoS+CF-Ack frame, independent of its NAV. Non-AP STAs should accept polled TXOPs by initiating a frame exchange sequence, independent of their NAV.

[0239] (11) For scheduling UL HCCA TXOP:

[0240] (a) The affiliated APs of the soft AP MLD simultaneously poll non-AP stations operating on the basic link and the conditional link, allocating the same polling TXOP duration.

[0241] (b) Polling of non-AP stations (which are non-AP QoS STAs whose own address matches the address 1 field of the received QoS CF polling frame) should not exceed the polling TXOP duration and any type of padding may be used to maintain PPDU end time alignment on the basic link and conditional link.

[0242] (b)(i) If a non-AP station being polled only uses a portion of the allocated TXOP, then the receiving AP should not poll until the polling TXOP on the other link is complete. The affiliated APs of the soft AP MLD should poll simultaneously.

[0243] (b)(ii) Polled non-AP stations may transmit multiple frame exchange sequences within a given polling TXOP, which is limited by the duration of the TXOP.

[0244] (12) For the scheduled DL HCCA TXOP:

[0245] (a) The affiliated AP of the soft AP MLD shall simultaneously send DL PPDU to the non-AP station operating on each link, allocating the same HCCA TXOP duration.

[0246] (b) The auxiliary AP of the soft AP MLD can transmit multiple frame exchange sequences within a given polling TXOP, which is limited by the duration of the TXOP.

[0247] (c) The auxiliary AP of the soft AP MLD can use any type of padding to align the end time of the transmitted PPDU.

[0248] (13) To avoid conflicts caused by hidden terminals, if both the basic link and the conditional link are idle at the TxPIFS time slot boundary, then two APs attached to the soft AP MLD can simultaneously send very small (compact) DL PPDU frames (e.g., RTS, empty, control, or management frames) on both links. The DL PPDU has NAV establishment to protect the TXOP duration.

[0249] (a) If any AP station fails to receive a CTS / ACK / BA as a response to a DL PPDU after SIFS, it indicates a possible collision. The process repeats step (13) after aSIFSTime+n*aSlotTime, where n is a random variable.

[0250] (b) If two APs receive CTS / ACK / BA as a response to DL PPDU after SIFS, then they should poll UL TXOP or send DL TXOP simultaneously on the basic link and the conditional link to set the updated NAV duration.

[0251] (c) For retransmissions of small DL PPDUs by two APs within the same soft AP MLD, the number of retransmissions on both links can be limited (in the case of an interfering AP acting as a hidden terminal sending a very long DL PPDU as interference). When the retransmission limit is met, the AP should poll the UL TXOP or send a DL TXOP independently if it receives a CTS / ACK / BA response as a short DL PPDU after SIFS. If the AP does not receive a CTS / ACK / BA response as a DL PPDU, it should neither poll the UL TXOP nor send a DL TXOP.

[0252] (14) The PS STA should obtain some QoS and admission information from the beacon.

[0253] 6.2. Method 2: Perform adaptive round-robin scheduling on conditional links based on the basic link status.

[0254] (1) Stations operating on the basic link access channel based on the EDCA strategy.

[0255] (2) Legacy (non-EHT) devices should access the conditional link based on the HCCA policy. EHT devices can access the conditional link through EDCA or HEMM, which is a hybrid HCCA / EDCA mode.

[0256] (3) The condition link AP knows about the UL / DL transmission on the basic link because the condition link AP and the basic link AP of the same soft AP MLD have the same SME.

[0257] (4) The condition link AP schedules UL / DL transmissions on the condition link based on the concurrent UL / DL transmissions on the basic link.

[0258] (5) One or more frame exchanges may occur in a scheduled TXOP on the conditional link. The start and end times of each PPDU in the frame exchange sequence on the conditional link should be aligned with the PPDU on the base link.

[0259] (6) Soft AP MLD, non-AP MLD and legacy STA can use any type of padding to align the end time of the transmitted PPDU.

[0260] (7) All stations comply with HCF's NAV rules. (Same as step 3 in Method 1).

[0261] (8) The AP of the soft AP MLD on the conditional link can negotiate with the non-AP legacy STA to agree on a large maximum SI value during admission control.

[0262] (a) The AP of the soft AP MLD can be scheduled using the maximum SI of the admitted TS in case it is unable to provide services to the TS at the scheduled time due to simultaneous transmission and reception on the basic link and the conditional link, or interference on the conditional link.

[0263] (b) If the next service start time meets the maximum SI value for acceptance on the conditional link, but any HCCA TXOP scheduling on the conditional link will result in asynchronous UL / DL transmission with concurrent basic link transmission, then the AP of the soft AP MLD on the conditional link should not serve the TS.

[0264] (9) For scheduled UL TXOPs, if the conditional link is available, then if the QoS CF polling can be aligned with the trigger frame (AP-initiated UL TXOP) or CTS frame (non-AP-initiated UL TXOP) sent by the base link AP attached to the same soft AP MLD, then the conditional link AP should send the polling frame to the non-EHT device on the conditional link.

[0265] (10) For a scheduled DL TXOP, if the conditional link is available, the conditional link AP in the same soft AP MLD should send a concurrent DL PPDU using the base link AP. If the conditional link AP has no DL PPDU to send, it can send a single DL NULL PPDU and set the NAV to the concurrent DL TXOP on the base link. If the conditional link AP has a DL PPDU to send after sending a DL NULL PPDU, it can send the DL PPDU on the conditional link, aligned with the end of the DL PPDU on the base link.

[0266] (11) For scheduled UL / DL TXOP, if the condition link is unavailable, the AP on the condition link should not send DL PPDU on the condition link.

[0267] 7. General Scope of the Embodiments

[0268] Embodiments of this technology may be described herein with reference to flowchart illustrations of methods and systems according to embodiments of this technology, and / or may also be described as processes, algorithms, steps, operations, formulas, or other computational depictions implemented as computer program products. In this regard, each block or step of a flowchart, combinations of blocks (and / or steps) in a flowchart, and any process, algorithm, step, operation, formula, or computational depiction may be implemented by various means, such as hardware, firmware, and / or software including one or more computer program instructions contained in computer-readable program code. As will be appreciated, any such computer program instructions may be executed by one or more computer processors (including, but not limited to, general-purpose or special-purpose computers, or other programmable processing means that produce a machine) to create means for implementing the specified functions(s).

[0269] Therefore, the blocks and processes, algorithms, steps, operations, formulas, or calculations depicted in the flowcharts described herein support combinations of means for performing one or more specified functions, combinations of steps for performing one or more specified functions, and computer program instructions (such as those implemented in computer-readable program code logic means) for performing one or more specified functions. It will also be understood that each block of the flowchart illustrations described herein, as well as any process, algorithm, step, operation, formula, or calculation depiction and its combination, can be implemented by a dedicated hardware-based computer system or a combination of dedicated hardware and computer-readable program code that performs the specified functions or steps.

[0270] Furthermore, computer program instructions, such as those implemented in computer-readable program code, may also be stored in one or more computer-readable storage media or memory devices, which may instruct a computer processor or other programmable processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage media or memory devices produce an article of art including instruction means that implement the functions specified in one or more blocks of one or more flowcharts. The computer program instructions may also be executed by a computer processor or other programmable processing apparatus to cause a series of operational steps to be performed on the computer processor or other programmable processing apparatus to produce a computer-implemented process, such that the instructions executing on the computer processor or other programmable processing apparatus provide steps for implementing the functions specified in one or more blocks, one or more processes, one or more algorithms, one or more steps, one or more operations, one or more formulas, or one or more calculations depicted in one or more flowcharts.

[0271] It will also be recognized that, as used herein, the terms "programmable program" or "executable program" refer to one or more instructions that can be executed by one or more computer processors to perform one or more functions as described herein. Instructions may be implemented as software, firmware, or a combination of software and firmware. Instructions may be stored locally on a device on a non-transitory medium, or remotely on a server, or all or part of the instructions may be stored both locally and remotely. Remotely stored instructions may be downloaded (pushed) to the device by user initiation or automatically based on one or more factors.

[0272] It will also be recognized that, as used herein, the terms processor, computer processor, central processing unit (CPU) and computer are used synonymously to refer to a device capable of executing instructions and communicating with input / output interfaces and / or peripheral devices, and the terms processor, computer processor, CPU and computer are intended to include single or multiple devices, single-core and multi-core devices and variations thereof.

[0273] As will be appreciated from the description herein, this disclosure covers various embodiments of the technology, including but not limited to the following:

[0274] An apparatus for wireless communication in a network, the apparatus comprising: (a) a wireless communication circuit of a soft access point (AP) multilink device (MLD) configured to wirelessly communicate with other wireless stations (STAs) via a basic link and a conditional link when performing multilink operation (MLO) on a wireless local area network (WLAN) in accordance with the IEEE 802 protocol, and configured to allow legacy (non-EHT) devices to establish link connections on the conditional link; (b) a processor coupled to the wireless communication circuit for operation as an STA on the WLAN; (c) a non-transitory memory storing instructions executable by the processor to communicate with other STAs; and (d) wherein the instructions, when executed by the processor, perform one or more steps, including: (d)(i) wherein the soft AP MLD has AP STAs for communication via the basic link and AP STAs for communication via the conditional link; (d)(ii) wherein the soft AP MLD has a station management entity (SME), APs on the basic link The STA and the APSTA on the conditional link cooperate with each other through the station management entity to simultaneously process Enhanced Distributed Channel Access (EDCA) Transmission Opportunity (TXOP) and HCF Controlled Channel Access (HCCA) TXOP through the basic link and the conditional link; (d)(iii) Admission control is performed on both the basic link and the conditional link, wherein a flow stream (TS) is established and negotiated in the EDCA TXOP, and the scheduling of the HCCA TXOP is based on the service period (SP) information for admission obtained during the TS establishment, wherein the access policy of HCCA admission is used on both the basic link and the conditional link; and (d)(iv) wherein APs attached to the same soft AP MLD schedule and allocate synchronized uplink (UL) or downlink (DL) TXOPs through both the basic link and the conditional link during the HCCA TXOP period.

[0275] An apparatus for wireless communication in a network, the apparatus comprising: (a) a wireless communication circuit of a soft access point (AP) multilink device (MLD) configured to wirelessly communicate with other radio stations (STAs) via a base link and a conditional link when performing multilink operation (MLO) on a wireless local area network (WLAN) in accordance with the IEEE 802 protocol, and configured to allow legacy (non-EHT) devices to establish link connections on the conditional link; (b) a processor coupled to the wireless communication circuit for operation as an STA on the WLAN; (c) a non-transitory memory storing instructions executable by the processor to communicate with other STAs; and (d) wherein the instructions, when executed by the processor, perform one or more steps, including: (d)(i) accessing the base link based on an enhanced distributed channel access (EDCA) policy; (d)(ii) for devices not configured to operate at extremely high throughput (EHT) and therefore non-EHT. (d)(iii) Access to the conditional link by the legacy station of the STA based on the HCF Controlled Channel Access (HCCA) strategy; (d)(iv) Access to the conditional link via EDCA or HCCA-EDCA hybrid mode (HEMM); (d)(iv) Where the access point (AP) accessing the conditional link can identify uplink / downlink (UL / DL) transmissions being performed on the basic link because the AP accessing the conditional link and the AP accessing the basic link of the same soft AP MLD share the station management entity (SME); (d)(v) Based on concurrent UL / DL transmissions on the basic link, the AP of the conditional link schedules a transmission opportunity (TXOP) as a UL / DL transmission on the conditional link; and (d)(vi) During the TXOP scheduled on the conditional link, one or more frames of physical layer protocol data units (PPDUs) are transmitted in a frame exchange sequence, wherein the start and end times of each PPDU during the frame exchange sequence on the conditional link are aligned with the PPDUs transmitted on the basic link.

[0276] A method for wireless communication in a network includes: (a) performing wireless communication between a soft access point (AP) multilink device (MLD) and other radio stations (STAs) via a base link and a conditional link while performing multilink operation (MLO) on a wireless local area network (WLAN) according to the IEEE 802 protocol, the protocol being configured to allow legacy (non-EHT) devices to establish link connections on the conditional link; (b) wherein the soft AP MLD has AP STAs for communicating via the base link and AP STAs for communicating via the conditional link; (c) wherein the soft AP MLD has a station management entity (SME) through which the AP STAs on the base link and the AP STAs on the conditional link cooperate to simultaneously process Enhanced Distributed Channel Access (EDCA) Transport Opportunity (TXOP) and HCF Controlled Channel Access (HCCA) TXOP via the base link and the conditional link; and (d) performing admission control on both the base link and the conditional link, establishing a traffic flow (TS) and negotiating in the EDCA TXOP, while the HCCA... The scheduling of TXOPs is based on the service period (SP) information of admission obtained during TS establishment, wherein the access policy of HCCA admission is used on both the basic link and the conditional link; and (e) wherein APs attached to the same soft AP MLD schedule and allocate synchronized uplink (UL) or downlink (DL) TXOPs on both the basic link and the conditional link during the HCCA TXOP period.

[0277] A method for wireless communication in a network includes: (a) performing wireless communication between a soft access point (AP) multilink device (MLD) and other wireless stations (STAs) via a base link and a conditional link while performing multilink operation (MLO) on a wireless local area network (WLAN) according to the IEEE 802 protocol, the protocol being configured to allow legacy (non-EHT) devices to establish link connections on the conditional link; (a) accessing the base link based on an enhanced distributed channel access (EDCA) policy; (b) accessing the conditional link for legacy stations not configured to operate at extremely high throughput (EHT) and therefore being non-EHT STAs, based on an HCF controlled channel access (HCCA) policy; (c) accessing the conditional link via EDCA or a hybrid HCCA-EDCA mode (HEMM); (d) wherein the access point (AP) accessing the conditional link can identify that uplink / downlink (UL / DL) transmission is being performed on the base link because the AP accessing the conditional link and the accessing soft AP are connected to the same soft AP. The MLD's base link AP's AP sharing station management entity (SME); (e) scheduling transmission opportunities (TXOPs) by the condition link AP as UL / DL transmissions on the condition link based on concurrent UL / DL transmissions on the base link; and (f) transmitting one or more frames of Physical Layer Protocol Data Units (PPDUs) in a frame switching sequence during the TXOP scheduled on the condition link, wherein the start and end times of each PPDU during the frame switching sequence on the condition link are aligned with the PPDUs transmitted on the base link.

[0278] Any apparatus or method of the foregoing embodiments, wherein scheduling and allocating synchronized UL or DL ​​TXOPs via basic and conditional links during an HCCA TXOP period includes: (a) scheduling synchronized HCCA TXOPs by an affiliated AP of a soft AP MLD based on SP information of acceptance obtained from TS establishment; and (b) obtaining information about the next TXOP duration request for queued traffic or traffic belonging to a specific TID from the TID subfield and QoS control subfield of received QoS data frames of all MAC Service Data Units (MSDUs); and (c) wherein, if the request belongs to a given TS, the AP of the soft AP MLD is configured to reallocate the TXOP.

[0279] In any of the apparatuses or methods described above, the SP information received from the TS is selected from a set of communication information including at least one of average data rate, nominal MSDU size, minimum PHY rate, remaining bandwidth tolerance, and maximum service interval and delay limit.

[0280] Any apparatus or method of the foregoing embodiments, wherein if a stream is added or dropped, the HCCA TXOP is reassigned by the STA scheduler.

[0281] In any of the apparatuses or methods described above, the service intervals (SIs) of different admitted traffic flows (TS) do not need to be the same, because the AP is configured to schedule TXOPs accordingly.

[0282] Any apparatus or method of the foregoing embodiments, wherein, under the condition of being limited to the duration of TXOP, multiple frame exchange sequences can be executed within an HCCA TXOP, and PPDUs on the basic link and conditional link have aligned start and end times.

[0283] Any apparatus or method of the foregoing embodiments, wherein padding may be used to align the end times of the transmitted individual PPDUs.

[0284] Any apparatus or method of the foregoing embodiments, wherein the simultaneously scheduled UL / DL HCCA TXOP can be used on the basic link and conditional link by a legacy STA, or an affiliated STA of the same or different non-AP MLD, or an affiliated STA of a non-AP MLD and a legacy STA.

[0285] In any of the foregoing embodiments of the apparatus or method, if two of the basic link and the conditional link are idle in the Transmission PCF Inter-Frame Space (PIFS), which serves as the TxPIFS time slot boundary, then the AP attached to the soft AP MLD simultaneously obtains both the basic link and the conditional link.

[0286] Any apparatus or method of the foregoing embodiments, wherein all STAs comply with the HCF NAV rules, and each frame transmitted under HCF contains an NAV duration value.

[0287] Any apparatus or method of the foregoing implementation, wherein during the scheduling of a UL HCCA TXOP: (a) the affiliated AP of the soft AP MLD simultaneously polls non-AP stations operating on the base link and condition link and allocating the same polling TXOP duration; and (b) a non-AP station polled by a non-AP QoS STA whose address matches the address 1 field of the received QoS CF polling frame is not allowed to exceed the polling TXOP duration; (b)(i) wherein if the polling non-AP station uses only a portion of the allocated TXOP, then the receiving AP does not perform polling until the polling TXOP on another link has been completed, while the affiliated AP of the soft AP MLD simultaneously polls; and / or (b)(ii) wherein the polling non-AP station transmits multiple frame-switching sequences within a given polling TXOP limited by the TXOP duration.

[0288] Any apparatus or method of the foregoing embodiments, wherein scheduling of DL HCCA TXOP includes: (a) a soft AP MLD's affiliated AP simultaneously sending DL PPDUs to non-AP stations operating on each link by allocating the same HCCA TXOP duration; (b) a soft AP MLD's affiliated AP transmitting multiple frame-switching sequences within a given polling TXOP limited by the TXOP duration; and (c) a soft AP MLD's affiliated AP being able to use padding to align the end times of the transmitted PPDUs.

[0289] In any of the foregoing embodiments of the apparatus or method, in order to avoid conflicts caused by hidden terminals, if both the basic link and the conditional link are idle at the TxPIFS time slot boundary, then two APs attached to the soft AP MLD simultaneously transmit DL PPDU frames without DATA payloads on both links, the DL PPDU having NAV establishment to protect the TXOP duration.

[0290] In any of the foregoing embodiments of the apparatus or method, the DL PPDU frame is selected from a frame group consisting of Ready to Send (RTS), empty, control, or management frames.

[0291] Any apparatus or method of the foregoing embodiments, wherein the power saving (PS) station obtains QoS and admission information from the received beacon frames.

[0292] Any apparatus or method of the foregoing implementation, wherein the AP of the conditional link of the soft AP MLD negotiates with the non-AP legacy STA to agree on a large maximum SI value during admission control.

[0293] In any of the foregoing embodiments of the apparatus or method, if the conditional link is available to perform a scheduled ULTXOP, and if the Quality of Service (QoS) Contention-Free (CF) polling is aligned with the trigger frame of an AP-initiated uplink (UL) TXOP or the clear transmission (CTS) frame of a non-AP-initiated UL TXOP, such as that sent by an AP attached to the base link of the same soft AP MLD, then the AP on the conditional link sends a polling frame to the non-EHT STA on the conditional link.

[0294] Any apparatus or method of the foregoing embodiments, wherein if a conditional link is available for scheduling of a DL TXOP, then the AP of the conditional link AP of the same soft AP MLD performs simultaneous transmission of downlink (DL) PPDU on the basic link.

[0295] Any apparatus or method of the foregoing embodiments, wherein if the AP of the conditional link has no DLPPDU to send, then it sends a single DL NULL PPDU, and the NAV is set to concurrent DL TXOP on the basic link.

[0296] Any apparatus or method of the foregoing embodiments, wherein if the AP on the conditional link has a DL PPDU to send after sending a DL NULL PPDU, then it can send the DL PPDU on the conditional link and have end alignment with the DL PPDU on the basic link.

[0297] In any of the apparatuses or methods described above, if the conditional link is not available for scheduling of the UL / DLTXOP, then the AP on the conditional link does not transmit the DL PPDU on the conditional link.

[0298] As used herein, the term “implementation” is intended to include, but is not limited to, embodiments, examples or other forms of practicing the techniques described herein.

[0299] As used herein, unless the context clearly indicates otherwise, the singular terms “a,” “an,” and “the” may include plural indications. Unless explicitly stated otherwise, references to objects in the singular are not intended to mean “one and only one,” but rather “one or more.”

[0300] The phrase constructs in this disclosure (such as “A, B and / or C”) describe situations in which A, B or C, or any combination of items A, B and C, may be present. Phrase constructs indicating, such as “at least one” followed by a list of element groups, indicate the presence of at least one of these group elements, which includes any possible combination of the listed elements (if applicable).

[0301] References to the terms "embodiment," "at least one embodiment," or similar embodiments in this disclosure indicate that a particular feature, structure, or characteristic described in connection with the described embodiments is included in at least one embodiment of this disclosure. Therefore, these various embodiment phrases do not necessarily refer to the same embodiment or a specific embodiment different from all other embodiments described. The term "embodiment" should be interpreted as meaning that a particular feature, structure, or characteristic of a given embodiment can be combined in any suitable manner in one or more embodiments of the disclosed apparatus, system, or method.

[0302] As used herein, the term "collection" refers to a set of one or more objects. Thus, for example, a collection of objects may include a single object or multiple objects.

[0303] Relational terms such as first and second, top and bottom can be used simply to distinguish one entity or action from another, without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0304] The terms “comprising,” “including,” “having,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes, has, or contains a list of elements includes not only those elements but may also include other elements not expressly listed or other elements inherent to such a process, method, article, or apparatus. Without further limitation, an element preceded by “comprising…,” “having…,” or “including…” does not preclude the presence of identically identical elements in a process, method, article, or apparatus that includes, has, or contains that element.

[0305] As used herein, the terms “approximately,” “approximately,” “substantially,” “essentially,” and “about,” or any variations thereof, are used to describe and explain small variations. When used with an event or situation, the term may refer to an instance where the event or situation happens exactly as well as instances where the event or situation occurs. When used with a numerical value, the term may refer to a range of variation less than or equal to ±10% of that value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, “substantially” may refer to a range of angular variation less than or equal to ±10° of that value, such as less than or equal to ±5°, less than or equal to ±4°, less than or equal to ±3°, less than or equal to ±2°, less than or equal to ±1°, less than or equal to ±0.5°, less than or equal to ±0.1°, or less than or equal to ±0.05°.

[0306] In addition, quantities, ratios, and other numerical values ​​may sometimes be presented in range format in this document. It should be understood that this range format is used for convenience and brevity and should be flexibly interpreted to include not only the numerical values ​​explicitly specified as range limits, but also all individual numerical values ​​or subranges contained within that range, as with each explicitly specified numerical value and subrange. For example, a ratio in the range of approximately 1 to approximately 200 should be understood to include the explicitly listed limits of approximately 1 and approximately 200, but also individual ratios such as approximately 2, approximately 3, and approximately 4, and subranges such as approximately 10 to approximately 50, approximately 20 to approximately 100, etc.

[0307] As used in this article, the term "coupling" is defined as a connection, but it is not necessarily direct and not necessarily mechanical. A device or structure that is "configured" in a certain way is configured at least in this way, but it may also be configured in ways not listed.

[0308] Benefits, advantages, solutions to problems, and any element(s) that may lead to or make any benefit, advantage, or solution appear or become more apparent shall not be construed as a technically critical, essential, or fundamental feature or element described herein or in all claims.

[0309] Furthermore, in the foregoing disclosure, various features may be combined in various embodiments for the purpose of simplification. This approach of the present disclosure should not be construed as reflecting an intention to claim more features than expressly listed in each claim. Inventive subject matter may be present in all features of a single disclosed embodiment.

[0310] An abstract of this disclosure is provided to allow the reader to quickly determine the nature of the technical disclosure. It is understood that this abstract is not intended to interpret or limit the scope or meaning of the claims.

[0311] It will be recognized that practice in some jurisdictions may require the deletion of one or more portions of this disclosure after the filing of an application. Therefore, readers should consult the filed application for the original contents of this disclosure. Any deletion of the contents of this disclosure should not be construed as a disclaimer, forfeiture, or public offering of any subject matter of the originally filed application.

[0312] The following claims are incorporated herein by reference, each of which stands independently as a separate subject matter.

[0313] While the description herein contains numerous details, these details should not be construed as limiting the scope of this disclosure, but rather as providing illustration of some currently preferred embodiments. Therefore, it will be appreciated that the scope of this disclosure fully covers embodiments that will become obvious to those skilled in the art.

[0314] All structural and functional equivalents of the elements of the disclosed embodiments known to those skilled in the art are expressly incorporated herein by reference and are intended to be covered by the claims of this application. Furthermore, regardless of whether an element, component, or method step is expressly stated in the claims, none of the elements, components, or method steps in this disclosure are intended for public use. The claims herein should not be construed as "component plus function" elements unless the element is expressly described using the phrase "component for...". The claims herein should not be construed as "step plus function" elements unless the element is expressly described using the phrase "step for...".

Claims

1. An apparatus for wireless communication in a network, the apparatus comprising: (a) The wireless communication circuitry of a soft access point (AP) multilink device (MLD) is configured to communicate wirelessly with other radio stations (STAs) via a basic link and a conditional link when performing multilink operation (MLO) on a wireless local area network (WLAN) in accordance with the IEEE 802 protocol, and is configured to allow legacy (non-EHT) devices to establish link connections on the conditional link. (b) A processor coupled to the wireless communication circuitry to operate as a STA on a WLAN; (c) Non-transitory memory, storing instructions that can be executed by the processor to communicate with other STAs; as well as (d) The instruction wherein, when executed by the processor, performs one or more steps, including: (i) wherein the soft AP MLD has an AP STA for communication via a basic link and an AP STA for communication via a conditional link; (ii) wherein the soft AP MLD has a station management entity (SME) through which AP STAs on the basic link and AP STAs on the conditional link cooperate to simultaneously process Enhanced Distributed Channel Access (EDCA) Transmission Opportunity (TXOP) and Hybrid Coordination Function (HCF) Controlled Channel Access (HCCA) TXOP through the basic link and the conditional link. (iii) Admission control is performed on both the basic link and the conditional link, wherein traffic flows (TS) are established and negotiated in the EDCA TXOP, and the scheduling of the HCCA TXOP is based on the service period (SP) information obtained during TS establishment, wherein the HCCA admission access policy is used on both the basic link and the conditional link; and (iv) During the HCCA TXOP period, APs attached to the same soft AP MLD schedule and allocate synchronized uplink (UL) or downlink (DL) TXOPs through both the basic link and the conditional link.

2. The apparatus of claim 1, wherein scheduling and allocating synchronized UL or DL ​​TXOPs via basic link and conditional link during the HCCA TXOP period comprises: (a) HCCATXOP synchronized by the affiliated AP of the soft AP MLD based on the SP information obtained from the TS establishment; as well as (b) Obtain information about the queued traffic of the AP STA corresponding to a specific Traffic Identifier (TID) or the next TXOP duration request for traffic belonging to a specific TID from the TID subfield and QoS control subfield of the received QoS data frames of all MAC Service Data Units (MSDUs); as well as (c) Wherein, if the request belongs to a given TS, then the AP of the soft AP MLD is configured to reallocate the TXOP.

3. The apparatus of claim 2, wherein the SP information received from the TS is selected from a set of communication information including at least one of average data rate, nominal MSDU size, minimum PHY rate, remaining bandwidth tolerance, and maximum service interval and delay limit.

4. The apparatus of claim 1, wherein, If a stream is added or dropped, the HCCA TXOP is reassigned by the STA scheduler.

5. The apparatus of claim 1, wherein, The service intervals (SIs) of different admitted traffic flows (TS) do not need to be the same, because the AP is configured to schedule TXOPs accordingly.

6. The apparatus of claim 1, wherein, Under the condition of being limited to the duration of TXOP, multiple frame switching sequences can be executed within HCCATXOP, and PPDUs on the basic link and conditional link have aligned start and end times.

7. The apparatus of claim 1, wherein padding is used to align the end times of the transmitted PPDUs.

8. The apparatus of claim 1, wherein the simultaneously scheduled UL / DL HCCA TXOP is used on the basic link and conditional link by a legacy STA, or an affiliated STA of the same or different non-AP MLD, or an affiliated STA of a non-AP MLD and a legacy STA.

9. The apparatus of claim 1, wherein, If both the basic link and the conditional link are idle in the Transmission PCF Inter-Frame Space (PIFS), which serves as the TxPIFS time slot boundary, then the AP attached to the soft AP MLD simultaneously acquires both the basic link and the conditional link.

10. The apparatus of claim 1, wherein, All STAs comply with the HCF NAV rules, and each frame transmitted under HCF includes an NAV duration value.

11. The apparatus of claim 1, wherein during the scheduling of uplink (UL) HCCA TXOP: (a) The auxiliary APs of the soft AP MLD simultaneously poll non-AP stations operating on both the base link and the condition link and allocating the same polling TXOP duration; as well as (b) Non-AP stations polled by a non-AP QoS STA whose own address matches the address 1 field of the received QoS CF polling frame are not allowed to exceed the polling TXOP duration; (i) where, If a non-AP station polling only uses a portion of its allocated TXOP, then the receiving AP does not perform polling until the polling TXOP on another link is completed, while the affiliated APs of the soft AP MLD simultaneously perform polling; and / or (ii) Wherein, A polling non-AP station transmits multiple frame exchange sequences within a given polling TXOP, which is limited by the TXOP duration.

12. The apparatus of claim 1, wherein performing the scheduling of DL HCCA TXOP comprises: (a) The affiliated APs of the soft AP MLD simultaneously send DL PPDUs to non-AP stations operating on each link by allocating the same HCCA TXOP duration; (b) The auxiliary AP of the soft AP MLD transmits multiple frame switching sequences within a given polling TXOP, which is limited by the duration of the TXOP; as well as (c) The auxiliary AP of the soft AP MLD uses padding to align the end time of the transmitted PPDU.

13. The apparatus of claim 1, wherein, To avoid conflicts caused by hidden terminals, if both the basic link and the conditional link are idle at the TxPIFS time slot boundary, then the two APs attached to the soft AP MLD simultaneously transmit DL PPDU frames without DATA payloads on both links, where the DL PPDU has NAV establishment to protect the TXOP duration.

14. The apparatus of claim 13, wherein the DL PPDU frame without DATA payload is selected from a frame group consisting of Ready to Send (RTS), empty, control, or management frames.

15. The apparatus of claim 1, wherein the power saving (PS) station obtains QoS and admission information from the received beacon frame.

16. An apparatus for conducting wireless communication in a network, the apparatus comprising: (a) The wireless communication circuitry of a soft access point (AP) multilink device (MLD) is configured to communicate wirelessly with other radio stations (STAs) via a basic link and a conditional link when performing multilink operation (MLO) on a wireless local area network (WLAN) in accordance with the IEEE 802 protocol, and is configured to allow legacy (non-EHT) devices to establish link connections on the conditional link. (b) A processor coupled to the wireless communication circuitry to operate as a STA on a WLAN; (c) Non-transitory memory, storing instructions that can be executed by the processor to communicate with other STAs; as well as (d) The instruction wherein, when executed by the processor, performs one or more steps, including: (i) Accessing the basic link based on the Enhanced Distributed Channel Access (EDCA) strategy; (ii) For legacy stations that are not configured to operate at extremely high throughput (EHT) and are therefore non-EHT STAs, access is provided to a conditional link based on the Hybrid Coordination Function (HCF) Controlled Channel Access (HCCA) strategy. (iii) Access conditional links via EDCA or HCCA-EDCA hybrid mode (HEMM); (iv) Where the access point (AP) of the access condition link is identified as performing uplink / downlink (UL / DL) transmission on the basic link because the AP of the access condition link and the AP of the basic link accessing the same soft AP MLD share the station management entity (SME). (v) Based on concurrent UL / DL transmissions on the basic link, transmission opportunities (TXOPs) are scheduled by the AP on the conditional link as UL / DL transmissions on the conditional link; and (vi) During a TXOP scheduled on the conditional link, one or more frames of physical layer protocol data units (PPDUs) are transmitted in a frame exchange sequence, wherein the start and end times of each PPDU during the frame exchange sequence on the conditional link are aligned with the PPDUs transmitted on the basic link.

17. The apparatus of claim 16, wherein padding may be used to align the end time of the transmitted PPDU.

18. The apparatus of claim 16, wherein the STA complies with the Network Assignment Vector (NAV) rules of the Hybrid Coordination Function (HCF) under IEEE 802.

11.

19. The apparatus of claim 16, wherein the AP on the conditional link of the soft AP MLD negotiates with the non-AP legacy STA to agree on a maximum SI value during admission control.

20. The apparatus of claim 16, wherein, If the conditional link is available to perform a scheduled UL TXOP, and if the Quality of Service (QoS) Contention-Free (CF) polling is aligned with the trigger frame of an AP-initiated uplink (UL) TXOP or the Clear Send (CTS) frame of a non-AP-initiated UL TXOP sent by an AP attached to the base link of the same soft AP MLD, then the AP on the conditional link sends a polling frame to the non-EHT STA on the conditional link.

21. The apparatus of claim 16, wherein, If a conditional link is available for scheduling a DL TXOP, then the AP of the conditional link AP of the same soft AP MLD sends downlink (DL) PPDUs simultaneously with the execution on the basic link.

22. The apparatus of claim 21, wherein, If the AP on the conditional link has no DL PPDU to send, it sends a single DL NULL PPDU, where the NAV is set to the concurrent DL TXOP on the basic link.

23. The apparatus of claim 22, wherein, If the AP on the conditional link has a DLPPDU to send after sending a DL NULL PPDU, then the DL PPDU is sent on the conditional link and is end-aligned with the DL PPDU on the basic link.

24. The apparatus of claim 23, wherein, If the conditional link is not available for scheduling UL / DL TXOP, then the AP on the conditional link will not transmit DL PPDU on the conditional link.

25. A method for wireless communication in a network, comprising: (a) When performing multilink operation (MLO) on a wireless local area network (WLAN) in accordance with the IEEE 802 protocol, wireless communication is conducted between a soft access point (AP) multilink device (MLD) and other wireless stations (STAs) via a basic link and a conditional link, the protocol being configured to allow legacy (non-EHT) devices to establish link connections on the conditional link. (b) wherein the soft AP MLD has an AP STA for communication via a basic link and an AP STA for communication via a conditional link; (c) The soft AP MLD has a station management entity (SME) through which AP STAs on the basic link and AP STAs on the conditional link cooperate to process Enhanced Distributed Channel Access (EDCA) Transmission Opportunity (TXOP) and HCF Controlled Channel Access (HCCA) TXOP simultaneously through the basic link and the conditional link. (d) Admission control is performed on both the basic link and the conditional link. Traffic flows (TS) are established and negotiated in the EDCA TXOP, while scheduling of the HCCA TXOP is based on the service period (SP) information obtained during TS establishment. The HCCA admission access policy is used on both the basic link and the conditional link. (e) APs attached to the same soft AP MLD schedule and allocate synchronized uplink (UL) or downlink (DL) TXOPs through both the basic link and the conditional link during the HCCA TXOP period.

26. A method for wireless communication in a network, comprising: (a) When performing multilink operation (MLO) on a wireless local area network (WLAN) in accordance with the IEEE 802 protocol, wireless communication is conducted between a soft access point (AP) multilink device (MLD) and other wireless stations (STAs) via a basic link and a conditional link, the protocol being configured to allow legacy (non-EHT) devices to establish link connections on the conditional link. (b) Accessing the basic link based on the Enhanced Distributed Channel Access (EDCA) strategy; (c) Access to a conditional link based on the HCF Controlled Channel Access (HCCA) policy for a legacy station that is not configured to operate at extremely high throughput (EHT) and is therefore a non-EHT STA; (d) Access conditional links via EDCA or HCCA-EDCA hybrid mode (HEMM); (e) Where the access point (AP) of the access condition link is identified as performing uplink / downlink (UL / DL) transmission on the basic link because the AP of the access condition link and the AP of the basic link accessing the same soft AP MLD share the station management entity (SME). (f) Based on concurrent UL / DL transmissions on the basic link, transmission opportunities (TXOPs) are scheduled by the AP on the conditional link as UL / DL transmissions on the conditional link; and (g) Transmit one or more frames of Physical Layer Protocol Data Units (PPDUs) in a frame switching sequence during a TXOP scheduled on the conditional link, wherein the start and end times of each PPDU during the frame switching sequence on the conditional link are aligned with the PPDUs transmitted on the base link.

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