Restricted Target Wait Time (R-TWT) Operations and Parameters

Abstract

The wireless protocol implements restricted target wait time (R-TWT) signaling and its parameters to reduce latency, such as for real-time application traffic. Further control of traffic flows is provided during the R-TWT service period (SP), including whether the R-TWT SP can be extended, whether multiple overlapping R-TWT SPs on different links can start, whether spatial reuse is required during the R-TWT SP, whether transmissions outside the R-TWT SP are allowed, or whether a silent element is used to protect the R-TWT SP, thereby describing R-TWT operations (modes) through enhanced operations. The protocol applies to wireless local area networks (WLANs), particularly to 802.11be, 802.11ax, real-time application (RTA) traffic, such as on time-sensitive networks, Wi-Fi, and on multi-link devices (MLDs).

Description

[0001] (Cross - Reference to Related Applications)

[0002] This application claims the priority and benefit of U.S. Patent Application Serial No. 17 / 679798, filed on February 24, 2022, which is incorporated herein by reference in its entirety. This application claims the priority and benefit of U.S. Provisional Patent Application Serial No. 63 / 211683, filed on June 17, 2021, which is incorporated herein by reference in its entirety. This application claims the priority and benefit of U.S. Provisional Patent Application Serial No. 63 / 192656, filed on May 25, 2021, which is incorporated herein by reference in its entirety.

[0003] (Statement Regarding Federally Sponsored Research or Development)

[0004] Not applicable.

[0005] (Notice of Copyrighted Material)

[0006] A portion of the material in this patent document may be subject to copyright protection under the copyright laws of the United States and other countries. The copyright owner does not object to the reproduction of the patent document or patent disclosure as it appears in the publicly available files or records of the United States Patent and Trademark Office, but reserves all copyrights in other cases. The copyright owner hereby does not waive any of its rights to keep this patent document confidential, including, but not limited to, its rights under 37 CFR 1.14. Field of the Invention

[0007] The technology of the present disclosure generally relates to using Target Wake Time (TWT) on a WLAN station, and more specifically, to setting a reserved TWT mode and its various parameters for enhanced TWT usage. Background Art

[0008] Target Wake Time (TWT) was first introduced in 802.11ah and has evolved to 802.11ax. The goal of TWT is to enable devices to determine when and how to wake up to send and receive data. For example, in 802.11ax, an access point can increase the device sleep time to save battery life. This aspect is particularly beneficial in roles such as the Internet of Things (IoT). TWT also provides a mechanism by which a wireless access point and similar devices negotiate a specific time to access the medium, which helps with spectrum efficiency.

[0009] However, TWT is mainly targeted at energy conservation and does not specifically address real - time latency reduction.

[0010] Therefore, there is a need for enhanced TWT processing. The present disclosure meets this need and provides additional benefits. Summary of the Invention

[0011] A method for performing Restricted Target Wait Time (R-TWT) signaling, where the R-TWT signaling is conveyed using bits in a broadcast TWT parameter set field for set parameters for R-TWT, and the broadcast TWT parameter set field is defined as reserved according to IEEE 802.11ax. R-TWT is particularly beneficial for use with real-time application traffic or other latency-sensitive traffic, especially traffic from stations operating in a low-power configuration and thus waking up to receive and transmit data.

[0012] In addition to indicating the R-TWT to be performed, additional parameters are described to specify traffic flows that can be transmitted during an R-TWT service period (SP), including a parameter indicating whether the R-TWT SP can be extended; a parameter indicating whether multiple overlapping R-TWT SPs on different links can start; a parameter indicating whether spatial reuse is required during the R-TWT SP; a parameter indicating whether a Quiet element is used to protect the R-TWT SP. Thus, the selection of the R-TWT operation (mode) is described together with enhanced operations and their associated parameters.

[0013] Specifically, the disclosed technique describes using reserved bits in the broadcast TWT parameter set field to establish an R-TWT parameter setting. For example, for the R-TWT parameter setting, reserved bits 5 to 7 of the broadcast TWT recommendation subfield and bit 15 (B15) in the request type field of the broadcast TWT parameter set field are used. Additionally, for enhanced R-TWT signaling, several of these additional parameters are described.

[0014] This disclosure applies to wireless local area networks (WLANs), particularly to 802.11be 802.11ax, real-time application (RTA) traffic (or latency-sensitive traffic), such as in time-sensitive networks, over Wi-Fi, and on multi-link devices (MLDs).

[0015] Other aspects of the techniques described herein will be presented in the following sections of the specification, where the purpose of the detailed description is to fully disclose the preferred embodiments of the technique without limiting it. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The techniques described herein will be more fully understood by reference to the following drawings, which are for explanatory purposes only:

[0017] Figure 1 is a hardware block diagram of a wireless station (STA) hardware according to at least one embodiment of the present disclosure.

[0018] Figure 2Is a hardware block diagram of a station configuration such as included in multi-link device (MLD) hardware according to at least one embodiment of the present disclosure.

[0019] Figure 3 Is a data field diagram of a broadcast TWT parameter set field utilized according to at least one embodiment of the present disclosure.

[0020] Figure 4 Is a data field diagram of a broadcast TWT information sub-field utilized according to at least one embodiment of the present disclosure.

[0021] Figure 5 Is a data field diagram of a request type sub-field from a broadcast TWT parameter set field utilized according to at least one embodiment of the present disclosure.

[0022] Figure 6 Is a flowchart of selecting each reserved bit to indicate an option of R-TWT setting according to at least one embodiment of the present disclosure.

[0023] Figure 7 Is a flowchart of identifying whether a received broadcast TWT parameter set field indicates using a first R-TWT signaling option according to at least one embodiment of the present disclosure.

[0024] Figure 8 Is a flowchart of identifying whether a received broadcast TWT parameter set field indicates using a second R-TWT signaling option according to at least one embodiment of the present disclosure.

[0025] Figure 9 Is a data field diagram of a request type sub-field in a broadcast TWT recommendation field using a first R-TWT signaling option according to at least one embodiment of the present disclosure.

[0026] Figure 10 Is a data field diagram of using reserved bits in a broadcast TWT information field R-TWT information according to at least one embodiment of the present disclosure.

[0027] Figure 11 Is a data field diagram of setting all SCSs (Stream Classification Service) that are not allowed according to at least one embodiment of the present disclosure.

[0028] Figure 12 Is a data field diagram of indicating the existence of a link ID bitmap utilized according to at least one embodiment of the present disclosure.

[0029] Figure 13 Is a flowchart of performing overlapping R-TWT SP on multiple links according to at least one embodiment of the present disclosure.

[0030] Figure 14Is a communication diagram of a first example of overlapping R-TWT on a multi-link (ML) utilized according to at least one embodiment of the present disclosure.

[0031] Figure 15 Is a communication diagram of a second example of overlapping R-TWT on an ML utilized according to at least one embodiment of the present disclosure.

[0032] Figure 16 Is a communication diagram of a third example of overlapping R-TWT on an ML utilized according to at least one embodiment of the present disclosure.

[0033] Figure 17 Is a communication diagram of a fourth example of overlapping R-TWT on an ML utilized according to at least one embodiment of the present disclosure.

[0034] Figure 18 Is a communication diagram of an example of an extended R-TWT SP according to at least one embodiment of the present disclosure.

[0035] Figure 19 Is a communication diagram of an example that does not allow R-TWT extension according to at least one embodiment of the present disclosure.

[0036] Figure 20 Is a communication diagram of setting parameterized spatial reuse reception (PSRR) to allow parameterized spatial reuse (PSR) according to at least one embodiment of the present disclosure.

[0037] Figure 21 Is a communication diagram of a first example of using a silent element according to at least one embodiment of the present disclosure.

[0038] Figure 22 Is a communication diagram of a second example of using a silent element according to at least one embodiment of the present disclosure. Detailed Description

[0039] 1. Introduction

[0040] The broadcast TWT (B-TWT) signaling defined in IEEE 802.11ax is also suitable for supporting restricted TWT (R-TWT) signaling. As defined in proposal P802.11be D1.31, a specific value (e.g., 4) of the broadcast TWT recommendation subfield of the broadcast TWT parameter set field can be used to indicate that the signaling is for R-TWT.

[0041] B-TWT allows an AP such as a TWT scheduling AP to schedule a TWT service period (SP) to exchange frames with other stations (STAs) that are STAs (or members of the TWT) scheduled for TWT. As a result of negotiation with the scheduling AP, a single STA can have membership in a broadcast TWT. A TWT scheduled STA shall not transmit frames to a TWT scheduling AP outside the broadcast TWT SP, and shall not transmit frames not included in a trigger-based (TB) high efficiency (HE) PPDU to a TWT scheduling AP within a trigger-enabled broadcast TWT SP, except that the STA may transmit frames within a negotiated individual TWT SP defined in accordance with Proposal P802.11ax_D8.0 in 26.8.2 (e.g., the individual TWT protocol).

[0042] The R-TWT SP can be scheduled and notified in the same manner as the B-TWT SP. If the signaling is for the R-TWT, the TWT SP in the signaling is scheduled for the R-TWT. Otherwise, the TWT SP in the signaling is scheduled for the B-TWT.

[0043] As described in the following sections, the present disclosure provides enhanced R-TWT signaling.

[0044] 2. Embodiments

[0045] The enhanced use of R-TWT can be implemented in various 802.11 hardware configurations, which are provided by way of example and not limitation.

[0046] 2.1. Station Hardware Configuration

[0047] Figure 1 Exemplary embodiment 10 of STA hardware configured to execute the protocol of the present disclosure is shown. An external I / O connection 14 is preferably coupled to an internal bus 16 of a circuit 12, on which a CPU 18 for executing a program implementing a communication protocol and a memory (e.g., RAM) 20 are connected. The host houses at least one modem 22 to support communication coupled to at least one RF module 24, 28, and each RF module 24, 28 is connected to one or more antennas 29, 26a, 26b, 26c~26n. The RF module having multiple antennas (e.g., an antenna array) allows beamforming to be performed during transmission and reception. In this way, the STA can transmit signals using multiple sets of beam patterns.

[0048] Bus 14 allows various devices to be connected to the CPU, such as sensors and actuators. Instructions from memory 20 are executed on processor 18 to execute a program implementing a communication protocol, which 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 understood that the programming is configured to operate in different modes (TXOP holder, TXOP sharing participant, source, intermediate, destination, first AP, other AP, station associated with the first AP, station associated with other APs, coordinator, coordinatee, AP in OBSS, and STA within OBSS, etc.), depending on the role it plays in the current communication environment.

[0049] Accordingly, the STA HW is shown configured with at least one modem and associated RF circuitry for providing communication on at least one frequency band. The present disclosure is mainly directed to the sub 6GHz frequency band.

[0050] It should be understood that the present disclosure may be configured with multiple modems 22, each modem coupled to any number of RF circuits. Generally, using a greater number of RF circuits will result in a wider coverage of the antenna beam direction. It should be understood that the number of RF circuits used and the number of antennas are determined by the hardware constraints of a particular device. When the STA determines that communication with adjacent STAs is not required, a portion of the RF circuits and antennas may be disabled. In at least one embodiment, the RF circuitry includes a frequency converter and an array antenna controller, etc., and is connected to multiple antennas that are controlled to perform beamforming for transmission and reception. In this way, the STA can transmit signals using multiple sets of beam patterns, with each beam pattern direction being regarded as an antenna sector.

[0051] In addition, it should be noted that multiple instances of the station hardware shown in the figure may be combined into a multi-link device (MLD), which generally has a processor and memory for coordinating activities, and a separate CPU and memory are not always required for each STA in the MLD.

[0052] Figure 2 Exemplary embodiment 40 showing the hardware configuration of a multi-link device (MLD) is presented. Multiple STAs are attached to the MLD, and each STA operates on a link at a different frequency. The MLD has an external I / O access to an application, which is connected to an MLD management entity 48 having a CPU 62 and a memory (e.g., RAM) 64 to allow execution of a program implementing a communication protocol at the MLD level. The MLD can assign tasks to each attached station connected to it and collect information from each attached station, exemplified here as STA 1 42, STA 2 44 to STA N 46 and information sharing among the attached STAs.

[0053] In at least one embodiment, each STA of the MLD has its own CPU 50 and memory (RAM) 52 coupled to at least one modem 54 via a bus 58, and the at least one 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 in an antenna array. The modem, in combination with the RF circuit and the associated antennas, 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 circuits for connecting to its own antennas.

[0054] It should be understood that according to a particular MLD embodiment, since the STAs of the MLD can share resources with each other and / or with the MLD management entity, each STA does not necessarily need its own processor and memory. It should be understood that the above MLD diagrams are given by way of example and not limitation, and the present disclosure can operate in a wide range of MLD embodiments.

[0055] 2.2. Data Fields for TWT

[0056] Figure 3 Exemplary embodiment 110 showing the broadcast TWT parameter set field is presented. As described in IEEE 802.11ax (Proposal P802.11ax_D8.0), the field is represented as request type, target wake time, nominal minimum TWT wake duration, TWT wake interval mantissa, and broadcast TWT information.

[0057] Figure 4 Exemplary embodiment 130 showing the broadcast TWT information (Info) sub - field is presented. The field is represented as reserved, broadcast TWT ID (identification), and broadcast TWT persistence.

[0058] Figure 5 Exemplary embodiment 150 showing the request type field in the broadcast TWT parameter set field is presented. The field is represented as TWT request, TWT setup command, trigger, last broadcast parameter set, flow type, broadcast TWT recommendation, TWT wake interval exponent, and reserved field.

[0059] 3. Problem Statement

[0060] The broadcast TWT recommendation sub - field provides an indication for R - TWT. However, in order to provide enhanced R - TWT operation as disclosed herein, it is necessary to determine what parameter settings should be included in the B - TWT signaling of R - TWT. The following is a list of some candidate parameter settings for R - TWT.

[0061] (a) Parameters specifying a traffic flow can be transmitted during the R-TWT SP. (i) A traffic flow can be identified by an SCS ID, a traffic identifier (TID), a real-time application (RTA) ID, or a user priority (UP). It should be noted that the RTA ID can be an ID representing one or more low-latency traffic flows. (ii) The R-TWT signaling frame may also carry a TSPEC element to specify that only the traffic under the traffic specification (TSPEC) element can be transmitted during the R-TWT SP. It should be noted that the flow classification service (SCS) allows flows to be arbitrarily mapped to the primary queue and the backup queue.

[0062] (b) Parameters indicating whether the R-TWT SP can be extended. For example, the R-TWT SP may not start at its scheduled start time. If the R-TWT SP starts late, the R-TWT SP can be extended after its scheduled end time.

[0063] (c) Parameters indicating whether multiple overlapping R-TWT SPs on different links can be started. Multiple overlapping R-TWT SPs can be scheduled on different links; thus there are two options. In the first option, only one of these scheduled overlapping R-TWT SPs can be started, and the others are cancelled. In the second option, multiple of these scheduled overlapping R-TWT SPs can be started.

[0064] (d) Parameters indicating whether spatial reuse is required during the R-TWT SP. For example, this parameter can require the scheduling AP of the R-TWT to use the parameterized spatial reuse transmission (PSRT) or parameterized spatial reuse reception (PSRR) physical layer convergence procedure (PLCP) protocol data unit (PPDU) defined by IEEE 802.11ax.

[0065] (e) Parameters indicating whether a silent element is used to protect the R-TWT SP. During the R-TWT SP, the scheduling AP can schedule silent intervals to prevent channel contention from STAs that are not members of the R-TWT SP. These STAs can enter the silent mode during the R-TWT SP after receiving the silent element command from the scheduling AP.

[0066] 4.0. Objectives of the present disclosure

[0067] This R-TWT disclosure has the following objectives.

[0068] (a) Use Figure 5The reserved bits in the broadcast TWT parameter set field are used to set the R-TWT parameter settings. For example, set the request type field in the broadcast TWT parameter set field. In the broadcast TWT recommendation subfield: retain the values of bits 5-7 of this field, and also retain B15 of the broadcast TWT parameter set field.

[0069] (b) In Figure 4 the broadcast TWT information subfield of, retain bits B0 to B2.

[0070] (c) Implement enhanced R-TWT operations.

[0071] 5.0. Embodiment

[0072] 5.1. Reserved bit options for representing R-TWT settings

[0073] Figure 6 Exemplary embodiment 170 shows the options of each reserved bit representing R-TWT settings. It should be noted that the definition of each reserved bit for R-TWT signaling is pre-determined in the protocol. In this flowchart, the protocol should select option 1 or option 2. This flowchart describes the parameters that the STA can set in the broadcast TWT parameter set field for R-TWT signaling. The STA can be a TWT scheduling AP or a single STA.

[0074] Specifically, the flowchart describes the STA reusing the broadcast TWT parameter set field 172 for R-TWT signaling and the selection 174 of option 1 or option 2. For option 1, the STA sets 176 the most significant bit of the broadcast TWT recommendation subfield to a first state (e.g., "1") to indicate that the signaling is for R-TWT, and the other bits are for R-TWT parameter settings. Then at block 180, the STA uses the other reserved bits in the broadcast TWT parameter set field for R-TWT parameter settings.

[0075] Otherwise, if it is determined at block 174 to use option 2, the STA sets 178 the broadcast TWT recommendation subfield to a value greater than or equal to 4 to indicate that the signaling is for a different type of R-TWT, after which it proceeds to the aforementioned block 180.

[0076] Figure 7 Shows an exemplary embodiment 190 describing whether the STA identifies that the received broadcast TWT parameter set field indicates R-TWT signaling when using option 1 from Figure 6 It should be understood that the STA can be a TWT scheduling AP or a single STA.

[0077] Specifically, the flowchart depicts that the STA receives the 192 broadcast TWT parameter set field, and then performs a check 194 to determine whether the most significant bit of the broadcast TWT recommendation subfield is set to a first state (e.g., "1").

[0078] If this bit is not set to the first state, the broadcast TWT parameter set field in the B-TWT signaling reaches block 200.

[0079] Otherwise, if this bit is in the first state, then execution moves from the check 194 to block 196, which identifies that the broadcast TWT parameter set field is set for R-TWT signaling. After that, the STA uses 198 the parameters found in the parameter set field of the broadcast TWT for R-TWT.

[0080] Figure 8 Illustrates an exemplary embodiment 210 of a flowchart depicting whether the received broadcast TWT parameter set field indicates R-TWT signaling when using option 2 from Figure 6 The flowchart explains how the STA identifies whether the received broadcast TWT parameter set field is used for R-TWT signaling when using option 2 from

[0081] It should be understood that the STA can be a TWT scheduling AP or a single STA. Figure 6 Specifically, the flowchart depicts that the STA receives 212 the broadcast TWT parameter set field, where a check 214 is performed on the broadcast TWT recommendation subfield to determine whether its value is equal to or greater than a set value, which is "4" when providing compatibility with the existing subfield value. If the value is not equal to or greater than this set value, it has been determined 220 to perform B-TWT signaling.

[0082] Otherwise, if at block 214 the value matches (is equal to or greater than the set value which is 4 in this case), then execution reaches block 216, through which it is determined that the broadcast TWT parameter set field indicates that R-TWT signaling is to be performed. Then in block 218, the STA uses the parameter settings in the broadcast TWT parameter set field for R-TWT.

[0083]

[0084] 5.2. Option 1: Each reserved bit represents an R-TWT setting

[0085] Figure 9 Illustrates an exemplary embodiment 230 of the request type field in the broadcast TWT recommendation subfield showing option 1 where each reserved bit represents an R-TWT setting

[0086] ​The request type field in the broadcast TWT parameter set field only contains B7 to B15. When it is used for R-TWT signaling, especially during R-TWT negotiation, additional bits can be added at any position in the request type field or in the broadcast TWT parameter set field for R-TWT parameter setting. It should be noted that the positions of the individual parameters can be changed.

[0087] The R-TWT indication subfield is at bit 9 (B9) of the request type field (or the most significant bit) in the broadcast TWT parameter set field. The R-TWT indication provides a one-bit indication for indicating whether the signaling is for R-TWT or for B-TWT. For example, when set to the first state (e.g., "1"), this indicates that the signaling is for R-TWT rather than B-TWT. Thus, for the TWT SP in the R-TWT SP scheduling signaling. Otherwise, the value of the broadcast TWT recommendation field is 0 to 3 for broadcast TWT signaling, and for the TWT SP in the B-TWT SP scheduling signaling.

[0088] For the other reserved bits in the broadcast TWT parameter set field, if the signaling is for R-TWT, the bits can be used to set the parameter set of R-TWT. It is possible that each option bit can be set only by the scheduling AP, and other STAs must follow the setting of the scheduling AP when sending the broadcast TWT parameter set for the same R-TWT.

[0089] Alternatively, in at least one embodiment, each option bit can be negotiated between the scheduling AP only and the STA requesting membership in the R-TWT. After the negotiation, the scheduling AP sets and broadcasts the option bit to other members, or the option bit is reserved when the scheduling AP broadcasts it.

[0090] For example, Figure 9 the overlapping R-TWT on the ML field in is set when the STA requests membership in the R-TWT, but is reserved (not used) when the scheduling AP broadcasts the broadcast TWT parameter set. If the option bit is reserved when the scheduling AP broadcasts it, the bit option is only effective between the scheduling AP and the R-TWT member STA (or the scheduled STA) that negotiated the option. If the option bit is set when the scheduling AP broadcasts it, the bit option is also effective for all member STAs of the corresponding R-TWT. It should be noted that the following descriptions of the options can represent the default operation of R-TWT, even if it is not a parameter set in the broadcast TWT parameter set field. For example, since R-TWT SP is always allowed by default, the extended R-TWT SP field may not be a parameter set in the broadcast TWT parameter set field.

[0091] Note that the following options can be any bit in the broadcast TWT parameter set field (including additional bits added to the broadcast TWT parameter set field for the R-TWT parameter set).

[0092] (1) Silent Element Protection: This bit indicates whether a silent interval is scheduled to protect the R-TWT SP. This subfield is set to a first state (e.g., "1") to indicate that the scheduling AP will use a silent element to schedule a silent interval to protect the R-TWT SP. The STA that receives this bit (or only the member STAs of the R-TWT SP) can ignore the silent intervals scheduled during the R-TWT SP. Otherwise, this subfield is set to a second state (e.g., "0"), and no silent interval is scheduled to protect the R-TWT SP.

[0093] (2) All SCS (or All Traffic Streams (TS)): This bit indicates whether traffic belonging to all SCS (or TS) is allowed to be transmitted during the R-TWT SP. If allowed, this field is set to a first state (e.g., "1"), or if not allowed, it is set to a second state (e.g., "0"), and only traffic belonging to the specified SCS (or TS) can be transmitted during the R-TWT SP. In at least one embodiment, SCS (or TS) setting information (such as SCS ID, TID, TSPEC element, or QoS characteristic element) may be included in a TWT signaling frame such as a TWT request / response frame.

[0094] (3) Extended R-TWT SP: This subfield can consist of a one-bit indication. If this bit is set to a first state (e.g., "1"), the R-TWT SP can be extended by members of the R-TWT (or only the scheduling AP); for example, if its R-TWT SP does not start as scheduled, or if members of the R-TWT cannot access the channel at the scheduled start time of the R-TWT SP.

[0095] Then, it is possible that the scheduling AP or a member STA may retain the TXOP during an R-TWT SP that exceeds the end time of the originally scheduled R-TWT SP. It should be noted that in at least one embodiment, the extended R-TWT SP time is constrained such that it is not longer than the transmission opportunity (TXOP) limit. Additionally, in at least one embodiment, the TXOP time obtained by the R-TWT members (including the scheduling AP) during the R-TWT SP is constrained such that it is not longer than the scheduled R-TWT SP time. In at least one embodiment, the R-TWT can be trigger-based, where only the AP can extend the R-TWT SP. Otherwise, the bit is set to a second state (e.g., "0"), and the R-TWT SP cannot be extended. The R-TWT SP must end at the scheduled end time, and the TXOP retained by the R-TWT members (including the scheduling AP) during the R-TWT SP cannot exceed the end time of the original schedule of the R-TWT SP. In at least one embodiment, if there is another R-TWT SP scheduled immediately following the current R-TWT SP schedule, the range of the R-TWT SP subfield of the current R-TWT SP should be set to a second state (e.g., "0"). In at least one embodiment, the scheduling AP makes the decision to set this subfield.

[0096] In some cases, the R-TWT SP can be extended only for DL transmissions of any member STA of the R-TWT SP and / or UL / P2P transmissions of member STAs of the R-TWT SP that do not contend for the channel outside the R-TWT SP.

[0097] (4) Required target wake-up: This subfield can be indicated by one bit. If this bit is set to a first state (e.g., "1"), the members of the R-TWT wake up and go to sleep according to the broadcast TWT. For example, the member STAs of the R-TWT wake up during the R-TWT SP and go to sleep outside the R-TWT SP. Otherwise, this bit is set to a second state (e.g., "0"), and the member STAs of the R-TWT always remain awake. Then, the scheduling AP can transmit DL transmissions (and / or trigger UL / P2P transmissions) to member STAs outside the R-TWT SP. It should be noted that the R-TWT SP is scheduled and notified in the same way as the B-TWT SP.

[0098] (5) Overlapping R-TWT on ML: This bit indication can be set to indicate whether the scheduling AP MLD and the same R-TWT MLD members are allowed to start multiple overlapping R-TWT SPs on different links. If this bit is set to the first state (e.g., "1"), the AP and the R-TWT members are allowed to start multiple R-TWT SPs on different links. In at least one embodiment, the use of silent intervals may not be allowed, thus protecting the R-TWT SP. Otherwise, this bit is set to the second state (e.g., "0"), and even if there are multiple overlapping R-TWT SPs scheduled on different links, the AP and the R-TWT members can only start one R-TWT SP on a link.

[0099] (6) PSRR: This bit indication can be used to indicate whether the AP must send a PSRR PPDU to trigger a UL transmission. If this bit is set to the first state (e.g., "1"), the AP is configured to send a PSRR PPDU during the R-TWT SP to trigger a UL transmission (PSRT PPDU). That is, the AP cannot set the spatial reuse field in the uplink (UL) spatial reuse subfield in the common information field of the trigger frame (PSRR PPDU) to PSR_DISALLOW or PSR_AND_NON-SRG_OBSS_PD_PROHIBITED to disallow OBSS STAs from performing SR transmissions based on parameterized spatial reuse (PSR). The spatial reuse value of the requested TBPPSU should follow the PSRR PPDU. When an overlapping basic service set (OBSS) STA receives this bit, it will recognize that there is a spatial reuse parameter (SRP) during the R-TWT SP.

[0100] Otherwise, this bit is set to the second state (e.g., "0"), and the AP does not send a PSRR PPDU when triggering a UL transmission. If the AP broadcasts this option, the OBSS STAs that receive this option can access the channel during parameterized spatial reuse (PSR) opportunities, and if the STAs within the basic service set (BSS) do not support SR based on PSR, they may not request membership in the R-TWT. The STAs within the BSS are also able to request a change to this option when they request membership.

[0101] (7) SR Enable: This bit can be used to indicate whether spatial reuse is allowed during the R-TWT SP. When this bit is set to the first state (e.g., "1"), the AP and members of the R-TWT can (or must) perform spatial reuse operations during the R-TWT SP, such as OBSS preamble detection (PD)-based spatial reuse and PSR-based spatial reuse defined in IEEE 802.11ax. The spatial reuse operations during the R-TWT SP can be the same as those outside the R-TWT. Otherwise, this bit is set to the second state (e.g., "0"), and the scheduling AP and members of the R-TWT are not allowed to perform spatial reuse operations during the R-TWT SP. If the AP broadcasts this option, the OBSS STA that receives this option can access the channel during the spatial reuse (SR) opportunity, and if the STA within the BSS does not support SR, it may not request membership in the R-TWT. The STA within the BSS can also request to change this option when it requests membership.

[0102] (8) TWT Protection: This bit is similar to the TWT protection request type field in a single TWT parameter set field.

[0103] (9) All TID: This bit is set to indicate whether it is allowed to transmit traffic belonging to all TIDs during the R-TWT SP. If it is allowed to transmit traffic belonging to all TIDs (possibly only low-latency traffic) during the R-TWT SP, this field is set to the first state (e.g., "1"), and the STA that is a member of the R-TWT can transmit traffic belonging to all TIDs to be transmitted during the R-TWT SP (possibly only low-latency traffic). Otherwise, this subfield is set to the second state (e.g., "0"), and only traffic belonging to the specified TID (possibly only low-latency traffic) can be transmitted during the R-TWT SP. The traffic information can be included in TWT signaling frames such as TWT request / response frames.

[0104] (10) Link ID Bitmap Existence: This bit can be used to indicate whether there is a Link ID Bitmap field in the broadcast TWT parameter set field. If this bit is set to the first state (e.g., "1"), the R-TWT signaling is for multi-link R-TWT, and the Link ID Bitmap field exists in the broadcast TWT parameter set field. The R-TWT SP should be scheduled on the links indicated in the Link ID Bitmap field. Otherwise, this bit is set to the second state (e.g., "0"), and the Link ID Bitmap field does not exist in the broadcast TWT parameter set field. The R-TWT signaling is only for the link through which the signaling is transmitted.

[0105] (11) Transmission outside the R-TWT is allowed: This field is set to a first state (e.g., "1") to indicate that member STAs of the R-TWT are allowed to contend for channel access outside the R-TWT SP (i.e., transmit frames). In the TWT request frame, this bit (set to "1") can also indicate that a single STA applying for R-TWT membership needs (or will) transmit (and / or receive) frames outside the R-TWT SP. In the TWT response frame, this bit (set to "1") can also indicate that the R-TWT scheduling AP can / will schedule UL (and / or DL and / or P2P) transmissions for member STAs of the R-TWT. Otherwise, this bit is set to a second state (e.g., "0") to indicate that member STAs of the R-TWT are not allowed (or should not) contend for channel access outside the R-TWT SP (which can also be transmission and reception). In the TWT request frame, this bit (set to "0") can also indicate that a single STA applying for R-TWT membership will not transmit (and / or receive) frames outside the R-TWT SP. In the TWT response frame, this bit (set to "0") can also indicate that the R-TWT scheduling AP will not schedule UL (and / or DL and / or P2P) transmissions for member STAs of the R-TWT.

[0106] It is possible that when a single STA sets this bit in the TWT request frame to indicate that it needs (or will) transmit (and / or receive) frames outside the R-TWT SP and the TWT request is accepted, the R-TWT scheduling AP only schedules (or triggers) UL (and / or DL and / or P2P) transmissions for individual STAs within the R-TWT SP for scheduling. For example, if the R-TWT SP is extended after the end time of scheduling, the R-TWT scheduling AP will not schedule UL (and / or DL and / or P2P) transmissions for individual STAs. That is, the UL (and / or DL and / or P2P) transmissions for individual STAs that are members of the R-TWT do not extend the R-TWT SP. It is possible that when an individual STA sets this bit in the TWT request frame to indicate that it does not transmit (and / or receive) frames outside the R-TWT and the TWT request is accepted, the R-TWT scheduling AP can extend the R-TWT SP for UL (and / or DL and / or P2P) transmissions of individual STAs that are members of the R-TWT SP.

[0107] This illustration depicts an example of an overlapping R-TWT with B7 for all SCS sub-fields, B8 for the silent element protection sub-field, and B15 for the ML sub-field. It should be noted that each reserved bit can be used for any R-TWT parameter set option. For example, all SCS sub-fields in B7 can be replaced by all TID sub-fields. It should be noted that if the request type field in the broadcast TWT parameter set field of the R-TWT is used for R-TWT signaling, it can add additional bits. For example, as shown in the figure, the PSRR field, SR enable field, TWT protection field, all TID fields, link ID bitmap presence field, transmission permission field outside the R-TWT are located in the additional bits for R-TWT parameter setting. It should also be understood that these additional bits can be located anywhere in the broadcast TWT parameter set field for R-TWT parameter setting.

[0108] 5.3. Example of Using Reserved Bits in Broadcast TWT Information

[0109] Figure 10 Exemplary embodiment 250 showing the use of reserved bits in the broadcast TWT information field. As shown in the example, when B-TWT signaling is used for R-TWT, the reserved bits B0 - B2 in the broadcast TWT information field can be used for R-TWT information. It should be noted that the reserved bits can be used for Figure 9 any of the fields shown.

[0110] (1) All SCS: This bit is set to indicate whether traffic belonging to all SCS is allowed to be transmitted during the R-TWT SP. This field is set to the first state (e.g., "1") to allow traffic belonging to all SCS to be transmitted during the R-TWT SP, and a STA that is a member of the R-TWT can transmit traffic belonging to all SCS that is to be transmitted during the R-TWT SP. Otherwise, this sub-field is set to the second state (e.g., "0"), and only traffic belonging to the specified SCS can be transmitted during the R-TWT SP. SCS setting information (e.g., SCS ID field, TSPEC element (or QoS characteristic element), TCLAS element, traffic classification (TCLAS) processing element, within-access-category priority element) can be included in a TWT signaling frame such as a TWT request / response frame. The SCS setting information can be used to set the SCS for the traffic to be transmitted during the R-TWT SP. In this example, if the all SCS field is set to the second state (e.g., "0"), the traffic from the SCS indicated in the SCS ID field can be transmitted during the R-TWT SP.

[0111] (2) AC: When this field is set to AC, traffic with a priority higher than or equal to the AC indicated in the AC field can be transmitted during the R-TWT SP. For example, the value of AC_BK is 0, the value of AC_BE is 1, the value of AC_VI is 2, and the value of AC_VO is 3. Since AC_VO and AC_VI have a higher priority than AC_BE, when this field is set to 1, the traffic of AC_VO, AC_VI, and AC_BE can be transmitted during the R-TWT SP. In some cases, only the traffic of the AC indicated in the AC field may be transmitted during the R-TWT SP.

[0112] (3) When the broadcast TWT information is used for R-TWT, the broadcast TWT ID represents the R-TWT ID. It should be noted that the scheduling AP or STA should not set the same ID as both R-TWT and broadcast TWT at the same time. In this way, the AP or STA can distinguish the broadcast TWT and the R-TWT by their IDs.

[0113] (4) The AC subfield can be carried by any other two reserved bits in the broadcast TWT parameter set field.

[0114] 5.4. Example of Setting All SCSs to Zero

[0115] Figure 11 Exemplary embodiment 290 shows setting all SCSs to not allowed (e.g., "0"). The upper part of the figure depicts the broadcast TWT information field, and the lower part of the figure depicts the broadcast TWT parameter set field.

[0116] (1) When the all-SCS field is set to "0" (the second state), traffic information such as SCSID, TSPEC (or QoS characteristic elements), and the TID of each traffic flow (i.e., of each traffic flow) can be included in the broadcast TWT parameter set field in a TWT signaling frame such as a TWT setup (request / response) frame. It should be understood that the all-SCS field can be replaced by any field that can indicate the existence of traffic information. In at least one embodiment, the SCSID, TID, and TSPEC fields (or QoS characteristic elements) may exist by default, for example, when sent by a non-AP STA to request membership in the R-TWT. The traffic information can be included at any position within the TWT signaling frame (such as in a TWT setup (request / response) frame).

[0117] (2) When traffic information exists in the broadcast TWT parameter set field of a broadcast TWT setup frame sent by a non-AP STA to request membership in an R-TWT, the traffic information specifies that traffic belonging to the traffic flow (between the non-AP STA and the scheduling AP) indicated in the traffic information needs to be transmitted during the R-TWT SP. When the scheduling AP receives this information, it can decide whether to accept the membership request based on this information. The following are two examples where the scheduling AP does not accept the membership request due to what is found in the traffic information.

[0118] (a) In at least one embodiment, if the total time required to transmit the traffic of all traffic flows indicated in the broadcast TWT parameter set field exceeds the amount of time that can be scheduled for the R-TWT SP, the membership request is not accepted. For example, the sum of the medium times in the TSPEC elements of all traffic flows indicated in the broadcast TWT parameter set field is longer than the time allowed per second for the scheduled R-TWT SP.

[0119] (b) In at least one embodiment, if the total time required to transmit the traffic of all traffic flows indicated in the broadcast TWT parameter set field exceeds the upper limit of the total time of all R-TWT SPs that the scheduling AP can schedule (or that the scheduling AP MLD can schedule on all links), the membership request is not accepted. There may be an upper limit to the total time of all R-TWT SPs that each scheduling AP can schedule in the network (or that the scheduling AP MLD can schedule on all links). If the transmission time of all traffic flows indicated in the broadcast TWT parameter set field (e.g., the sum of the medium times in the TSPEC elements of all traffic flows indicated in the broadcast TWT parameter set field is equal to 60 ms per second) requires the scheduling AP to schedule R-TWT SP time, and this R-TWT SP time causes the total time of all R-TWT SPs of the scheduling AP (or the scheduling AP MLD) to exceed the upper limit (e.g., upper limit = 5 ms per beacon interval (e.g., 0.1 s) or approximately 5 ms / 0.1 s = 50 ms / s < 60 ms / s), then the scheduling AP can reject the membership request.

[0120] (3) When traffic information exists in the broadcast TWT - parameter set field of a broadcast TWT setup frame sent by the scheduling AP to accept a membership request for an R-TWT, the traffic information can represent the traffic that is allowed to be transmitted during the scheduled R-TWT SP (transmitted between the non-AP STA and the scheduling AP), while other traffic (transmitted between the non-AP STA and the scheduling AP) may not be allowed to be transmitted or may be transmitted with a lower priority (compared to the traffic indicated in the traffic information) during the R-TWT SP.

[0121] (4) When traffic information exists in the broadcast TWT parameter set field of the broadcast TWT setup frame sent by the scheduling AP in response to the membership request of the R-TWT and the TWT setup command field in the response frame is Alternate TWT or Dictation TWT, the traffic information may represent traffic proposed to be transmitted during the R-TWT SP (transmitted between the non-AP STA and the scheduling AP). The non-AP STA may send another request frame with the proposed traffic information to request membership in the R-TWT.

[0122] (5) More SCS / TID: This field is set to a first state (e.g., "1") to indicate that there is more traffic information, such as SCS ID, TSPEC, and TID for another traffic flow. Otherwise, this bit is set to a second state (e.g., "0").

[0123] (6) Traffic information can be used to identify traffic, such as differentiating delay-sensitive traffic under an SCS or TSPEC from other traffic.

[0124] (7) It should be noted that the scheduling AP MLD is an MLD with multiple schedules attached to different links. It is possible that one traffic flow (such as an SCS) can be mapped to only one R-TWT of the scheduling AP MLD, or can be mapped to only one R-TWT of the scheduling AP on one link. For example, one SCS can be mapped to only one R-TWT. That is, when an R-TWT is allowed to transmit traffic of an SCS during its R-TWT SP, other R-TWTs should not accept requests to transmit traffic of that SCS during their R-TWT SPs.

[0125] 5.5. Example of the Existence of the Set Link ID Bitmap

[0126] Figure 12 An exemplary embodiment 310 indicating the existence of the link ID bitmap is shown. The upper part of the figure depicts the request type field in the broadcast TWT parameter set field of the R-TWT, while the lower part of the figure depicts the broadcast TWT parameter set field.

[0127] When the signaling is for the R-TWT and the link ID bitmap existence is set to a first state (e.g., "1") in the signaling, then the link ID bitmap exists in the broadcast TWT parameter set field.

[0128] As shown in the figure, B15 of the request type field in the broadcast TWT parameter set field of the R-TWT is used to carry the link ID bitmap existence field. Although any reserved bit in the broadcast TWT parameter set field can operate in the same manner as B15 of the request type field in the broadcast TWT parameter set field.

[0129] Link ID bitmap: This field consists of a series of bits, each bit being pre-set or mapped to a link. If a bit is set to a first state (e.g., "1"), then an R-TWT is set for the link regarding that bit. Otherwise, the bit is set to a second state (e.g., "0"), and the R-TWT is not used for the link regarding that bit. It should be noted that this is one possible way to schedule overlapping R-TWT SPs on multiple links. It should also be noted that there are sub-fields in the link ID bitmap that can also be used for broadcast TWT settings on multiple links. It should be noted that in the link ID bitmap field, not only one bit can be set to "1".

[0130] 5.6. Option 2: Each value represents an R-TWT option

[0131] In Option 2, the bit values of bits 4 to 7 in the broadcast TWT recommendation field represent an R-TWT with a default parameter set.

[0132] By way of example and not limitation, each value between 4 and 7 can be set to represent one of the following R-TWT settings:

[0133] - Basic R-TWT, or

[0134] - R-TWT with a silent element or protection, or

[0135] - R-TWT with a silent element or protection and only for a specified SCS, or

[0136] - R-TWT only for a specified SCS, or

[0137] - Overlapping R-TWT on the ML, or

[0138] - Overlapping R-TWT on the ML only for a specified SCS, or

[0139] - R-TWT that does not require a target wake-up, or

[0140] - The constraints on the frames transmitted during the R-TWT SP are similar to those of the R-TWT with values 0 to 3.

[0141] In this example, for instance, the value 4 represents a basic R-TWT. It should be understood that the values can be mapped in any desired sequence without departing from the teachings of the present disclosure.

[0142] 5.6. Overlapping R-TWT SPs on Multiple Links

[0143] Figure 13Exemplary embodiment 330 showing the execution of overlapping R-TWT SPs on multiple links. The overlapping R-TWTs on different links are R-TWTs managed by the scheduling AP MLD, and their R-TWT SPs on different links are scheduled over the same time period. It should be noted that overlapping R-TWTs may only represent those serving the same TID or the same SCS or traffic flow or the same MLD member.

[0144] Specifically, the operation depicts scheduling 332 multiple overlapping R-TWT SPs on different links for the same R-TWT members over the same time period.

[0145] Check 334 determines whether overlapping R-TWTs on multiple links are allowed. For example, this may include checking whether the ML subfield is set to a first state (e.g., "1"), indicating that overlapping R-TWTs on ML are allowed, while if the overlapping R-TWT on the ML subfield is set to a second state (e.g., "0"), overlapping R-TWTs on ML are not allowed.

[0146] If overlapping R-TWTs on multiple links are not allowed, then in block 338, if the process determines to start an R-TWT SP on one link, other overlapping R-TWT SPs on other links scheduled over the same time period are to be cancelled.

[0147] Otherwise, if overlapping R-TWTs on multiple links are allowed, then in block 336, if the process determines that an R-TWT SP starts on one link, other overlapping R-TWT SPs on other links scheduled over the same time period may still start.

[0148] 5.7. Example of Overlapping R-TWT on ML

[0149] Figure 14 Exemplary embodiment 350 showing a first example of overlapping R-TWT on ML (overlapping R-TWT on ML = 0).

[0150] The illustration depicts an MLD 352 with AP1 354 and AP2 356.

[0151] There are multiple overlapping R-TWT SPs, such as R-TWT SP1 358 and SP2 360 scheduled on different links (e.g., link 1 and link 2). For the overlapping R-TWT SPs, the overlapping R-TWT on the ML field is set to 0. The MLD member starts 364 R-TWT SP2 366 on link 2.

[0152] All MLDs operating on Link 1 and Link 2 can confirm that R-TWT SP2 starts on Link 2, for example, by sensing a frame indicating the start of R-TWT SP2. And since the overlapping R-TWT on the ML field = 0, it will be recognized that R-TWT SP1 on Link 1 is cancelled 362. Then, all MLDs (or only MLDs that are not R-TWT members) can contend for the channel on Link 1 during R-TWT SP1. If there is a silent interval scheduled during R-TWT SP on Link 1, the STA operating on Link 1 can ignore the silent interval.

[0153] AP2 or an R-TWT SP2 member can send a frame to indicate the start of R-TWT SP2. This frame can be, for example, a clear to send (CTS) frame having a specific receiver address (RA) field indicating the start of R-TWT SP2. The RA field of the frame (e.g., CTS) can be set to a specific ID of the link that can be mapped to an R-TWT ID and / or a STA ID and / or a BSS ID. In at least one embodiment or implementation, the RA field of the frame can be set to the address of AP2. Other stations (nodes) can determine the start of R-TWT SP2 scheduled by AP2.

[0154] Figure 15 Exemplary embodiment 370 showing a second example of overlapping R-TWT on the ML (overlapping R-TWT on the ML = 0). This diagram depicts the communication between MLD 352 with its AP1 354 and AP2 356 and another MLD 396 that is not a member of the R-TWT and has associated stations STA1 398 and STA2 400.

[0155] There are multiple overlapping R-TWT SPs, here illustrated as R-TWT SP1 372 and SP2 374, scheduled on different links shown as Link 1 and Link 2. For overlapping R-TWT SPs, the overlapping R-TWT field on the ML field is set to 0. The MLD member starts 378 R-TWT SP2 380 on Link 2.

[0156] All MLDs operating on Link 1 and Link 2 confirm that R-TWT SP2 starts on Link 2, such as by sensing a frame indicating the start of R-TWT SP2, etc. And since the overlapping R-TWT on the ML field = 0, they recognize that R-TWT SP1 on Link 1 is cancelled 376.

[0157] Then, all MLDs (or only those MLDs that are not members of the R-TWT) can contend for the channel on Link 1 during R-TWT SP1. If there is a silent interval scheduled during the R-TWT SP on Link 1, those MLDs operating on Link 1 can ignore the silent interval.

[0158] AP2 or an R-TWT SP2 member can send a frame to indicate the start of R-TWT SP2. The frame can be a CTS frame with a specific RA indicating the start of R-TWT SP2. The RA field of the frame (e.g., CTS) can be set to a specific ID of the link that can be mapped to the R-TWT ID and / or STA ID and / or BSS ID. The RA field of the frame can also be set to the address of AP2. Other nodes can recognize the start of R-TWT SP2 scheduled by AP2.

[0159] The AP (e.g., AP1) affiliated with the same MLD that is a member of R-TWT SP2 on Link 1 can access the channel on Link 1 for communication until the R-TWT on Link 2 ends for the following purposes only. The scheduling AP can access the channel to send a frame (such as a QoS Data or QoS Null frame with the EOSP subfield equal to 1) to indicate the end of R-TWT SP1 as it is cancelled. The AP can access the channel to serve its R-TWT members whose MLDs are not members of the R-TWT on Link 2. The AP can access the channel to send a frame (e.g., CF-End) to indicate the end of the R-TWT SP on Link 1 shown as 384 in the figure or the end of the silent time. The TA field of the frame (e.g., CF-End) can be set to a specific ID of the link that can be mapped to the R-TWT ID and / or STA ID and / or BSS ID.

[0160] The AP can access the channel to send DL traffic (or only DL traffic not allowed to be transmitted during the R-TWT SP) to its associated STA or trigger UL traffic (or only UL traffic not allowed to be transmitted during the R-TWT SP). The AP can access the channel to send control frames or management frames. For example, the illustration shows a PPDU 386 sent from AP1 to STA1 on Link 1, followed by a block acknowledgment (BA) 388 from the STA. A trigger frame (TF) 390 is shown sent from AP1 to STA1, and in response to it, a trigger-based (TB) PPDU 392 from STA1 to AP1, followed by a BA 394 from AP1.

[0161] In at least one embodiment, R-TWT members may classify events by indicating the end / termination of the R-TWT SP in the same manner as the B-TWT in IEEE 802.11ax.

[0162] Figure 16 Exemplary embodiment 410 showing a third example of overlapping R-TWTs on the ML (overlapping R-TWTs on the ML = 0). The illustration depicts an MLD 352 with an AP1 354 and an AP2 356.

[0163] There are multiple overlapping R-TWT SPs, illustrated as R-TWT SP1 358 and SP2 360, that schedule the same MLD members on different links shown as Link 1 and Link 2. For overlapping R-TWT SPs, the overlapping R-TWT field on the ML field is set to 0. The MLD member starts 364 R-TWT SP2 366 on Link 2.

[0164] All MLDs operating on Link 1 and Link 2 can confirm the start of R-TWT SP2 on Link 2, such as by receiving a frame indicating the start of R-TWT SP2, and then, since the overlapping R-TWT field on the ML field = 0, identify that R-TWT SP1 on Link 1 is cancelled 362. Then, all MLDs (or only MLDs that are not R-TWT members) can contend for the channel on Link 1 during R-TWT SP1. If there is a silent interval scheduled during R-TWT SP on Link 1, the MLDs operating on Link 1 can ignore the silent interval.

[0165] STA attached to the same MLD that is an R-TWT member on Link 1 may not be allowed to access the channel on Link 1 until the R-TWT SP2 on Link 2 ends. The R-TWT SP2 368 on Link 2 may end 370 earlier than it is scheduled. The AP2 or other R-TWT SP2 members can send a frame (e.g., a contention-free (CF)-End as in the previous example) to indicate the end of R-TWT SP2. The frame (e.g., CF-End) can indicate the end of the silent interval on Link 2.

[0166] An AP (e.g., AP1) that is a member of the same MLD as the R-TWT SP2 attached to Link 1 can access the channel on Link 1 until the R-TWT SP on Link 1 (or Link 2) ends solely for the following purposes. The AP can access the channel to serve R-TWT members whose MLDs are not members of the R-TWT on Link 2. The AP can access the channel to send a frame (e.g., CF-End) to indicate the end of the R-TWT SP or the end of the silent period on Link 1. The TA field of the frame (e.g., CF-End) can be set to a specific ID of the link that can be mapped to the R-TWT ID and / or STA-ID and / or BSS ID. The AP can access the channel to send downlink (DL) traffic to its associated STAs (or just DL traffic that is not allowed to be transmitted during the R-TWT SP) or trigger uplink traffic (or just UL traffic that is not allowed to be transmitted during the R-TWT SP). The AP can access the channel to send control frames or management frames.

[0167] Figure 17 Exemplary embodiment 450 showing a fourth example of overlapping R-TWTs on the ML. In this example, up to two overlapping R-TWT SPs on different links are allowed during the same time period. The illustration depicts an MLD 452 with AP1 454, AP2 456, and AP3 458.

[0168] The illustration represents an overlapping R-TWT with ML = 1, and there are scheduled R-TWT SPs 460, 462, and 464. In this example, only a limited number of overlapping R-TWT SPs are allowed to start on different links. In the example, at most two overlapping R-TWT SPs can start (or be initiated) during the same R-TWT SP time period on different links. This example can work only if the trigger subfield in the request type field in the broadcast TWT parameter set field = 1.

[0169] It can be seen that AP2 starts 466 R-TWT SP2 on Link 2, and then, when AP3 starts 470 R-TWT SP3 on Link 3, R-TWT SP1 is cancelled 468.

[0170] Figure 18An exemplary embodiment 490 of an extended R-TWT SP is shown. The illustration shows an example of extending the R-TWT SP such as when the sub-field Extend R-TWT SP is set to a first state (e.g., "1"), which indicates that the R-TWT SP is extended. In the illustration, it can be seen that the AP or STA has an R-TWT SP 494 with a schedule that can be extended for a time period time1 502. The AP or other R-TWT members can start 496 the R-TWT SP (e.g., the time to obtain channel access and obtain the TXOP) within the time period time2 498 until the R-TWT SP ends 504. The present disclosure can provide many options for R-TWT SP extension.

[0171] By way of example and not limitation, the following options for restricting R-TWT SP extension are provided.

[0172] Option 1: time1 should not be longer than the TXOP limit.

[0173] Option 2: time1 should not be longer than a given fraction (e.g., 50%) of the TXOP limit duration.

[0174] Option 3: time2 should not be longer than the TXOP limit.

[0175] Option 4: time2 should not be longer than a given fraction (e.g., 50%) of the TXOP limit.

[0176] Option 5: time2 should not be longer than the scheduled R-TWT SP time.

[0177] Option 6: time1 should not exceed the next target beacon transmission time.

[0178] Option 7: An AP or STA that is a member of the R-TWT SP can extend the R-TWT SP when it obtains the TXOP during the scheduled R-TWT SP and the TXOP duration exceeds the end time of the scheduled R-TWT SP. The R-TWT SP is extended to the end time of the TXOP.

[0179] Option 8: An AP or STA that is a member of the R-TWT SP can extend the R-TWT SP when it starts a PPDU transmission during the scheduled R-TWT SP and the PPDU duration and the requested transmission exceed the end time of the scheduled R-TWT SP. The R-TWT SP is extended to the end time of the PPDU transmission and its requested transmission.

[0180] The TXOP limit can be the TXOP limit of the AC that obtains the TXOP. The TXOP limit can also be the TXOP limit of the AC whose traffic is scheduled to be transmitted during the R-TWT SP for the highest priority TID. The TXOP limit can also be the maximum TXOP limit of the TIDs whose traffic is scheduled to be transmitted during the R-TWT. The TXOP limit can be a value set only for the R-TWT SP.

[0181] Figure 19 Exemplary embodiment 510 when R-TWT extension is not allowed is shown. This example represents the case where the R-TWT SP is not allowed to be extended. For example, when the subfield Extend R-TWT SP is set to the second state indicating that extension is not allowed (e.g., "0").

[0182] The AP or STA 512 is shown as having a scheduled R-TWT SP 514. The AP2 or other R-TWT member accesses the channel 516 until the maximum TXOP length 518.

[0183] As shown in the figure, the R-TWT SP cannot be extended. When an R-TWT member accesses the channel during the R-TWT SP, it cannot retain a TXOP that exceeds the end time 520 of the R-TWT.

[0184] Figure 20 Exemplary embodiment 530 of setting the PSRR to allow PSR (such as setting the PSRR to the first state (e.g., "1")) is shown. The AP1 should always set the parameters in the PSRR PPDU to allow PSR.

[0185] AP1 532 and AP2 534 are shown as having an R-TWT SP on link 1 536 such that the AP1 accesses the channel to start 538 the R-TWT SPT with the PSRR PPDU 540. This illustration also exemplifies the received TB PPDU 542 during which the AP2 sends the PSRT PPDU 544 representing the block acknowledgment 546.

[0186] In this example, the AP1 cannot set the spatial reuse field in the UL space reuse subfield of the common information field of the trigger frame (PSRR PPDU) to PSR_DISALLOW or PSR_AND_NON-SRG_OBSS_PD_PROHIBITED to disallow OBSS STAs from performing PSR-based SR transmissions. The spatial reuse value of the requested TB PPSU should follow the PSRR PPDU.

[0187] 5.8. Using the silence element to schedule the silent time

[0188] In at least one embodiment or aspect, a silent element is utilized to schedule silent time within an R-TWT SP to protect the R-TWT SP. The silent interval shall not exceed the R-TWT SP time. The end of the silent time shall be aligned with the end time of the R-TWT SP (and / or the start time of the silent time shall be aligned with the start time of the R-TWT SP).

[0189] If an R-TWT SP member accesses the channel during an R-TWT for R-TWT purposes, it may send a certain frame (e.g., CF-End) to cancel the silent time scheduled during the silent time.

[0190] If the end of an R-TWT SP occurs earlier than it is scheduled, it may send a certain frame (e.g., CF-End) to cancel the silent time scheduled during the current R-TWT SP.

[0191] Figure 21 Exemplary embodiment 550 showing a first example of using a silent element, wherein the end time of the silent interval is aligned with the end time of the R-TWT SP.

[0192] This diagram represents AP1 552 on link 1, STA1 554 as a member of the R-TWT on link 1, and STA2 556 which is not a member of the R-TWT on link 1.

[0193] An R-TWT SP on link 1 558 is shown during which AP1 560 accesses the channel to start the R-TWT SP on link 1. The scheduled silent interval 562 starts on link 1 such that STA2 enters 564 the silent mode. The end of the silent time interval coincides with the end of the R-TWT SP 566 on link 1, and STA2 ends 568 its silent mode here.

[0194] Figure 22 Exemplary embodiment 570 showing a second example of using a silent element. This diagram represents the same stations as in the previous example.

[0195] The R-TWT SP 572 on link 1 is shown to occur at the time when the silent element schedules a silent interval 574 on link 1. In response, STA2 enters 576 the silent mode.

[0196] AP1 accesses 578 the channel to start the R-TWT SP on link 1. The end of the silent time interval coincides with the end of the R-TWT SP 580 on link 1, and STA2 ends 582 its silent mode here.

[0197] 6. General scope of the embodiments

[0198] This document may describe embodiments of the present technology with reference to flowcharts of methods and systems according to embodiments of the present technology and / or also in terms of processes, algorithms, steps, operations, formulas, or other computational descriptions that can be implemented as a computer program product. At this point, each block or step of the flowchart, combinations of blocks (and / or steps) in the flowchart, and any process, algorithm, step, operation, formula, or computational description can be implemented by various means such as hardware, firmware, and / or software including one or more computer program instructions implemented in computer-readable program code. It will be understood that any such computer program instructions can be executed by one or more computer processors or other programmable processing devices including, but not limited to, general-purpose or special-purpose computers to create a machine such that the computer program instructions executed on the computer processor or other programmable processing device create means for implementing the specified functions.

[0199] Accordingly, the blocks of the flowcharts described herein, as well as the processes, algorithms, steps, operations, formulas, or computational descriptions, support combinations of means for performing the specified functions, combinations of steps for performing the specified functions, and computer program instructions such as embodied in computer-readable program code logic means for performing the specified functions. It should also be understood that the blocks of the flowcharts described herein, as well as any process, algorithm, step, operation, formula, or computational description and combinations thereof, can be implemented by a special-purpose hardware-based computer system that performs the specified functions or steps, or by a combination of special-purpose hardware and computer-readable program code.

[0200] In addition, such computer program instructions, as embodied in computer-readable program code, can also be stored in one or more computer-readable memories or memory devices, which can direct a computer processor or other programmable processing device to operate in a particular manner such that the instructions stored in the computer-readable memory or memory device produce a manufacture including instruction means for implementing the functions specified in the blocks of the flowchart. The computer program instructions can also be executed by a computer processor or other programmable processing device to cause a series of operational steps to be executed on the computer processor or other programmable processing device to produce a computer-implemented process such that the instructions executed on the computer processor or other programmable processing device provide steps for implementing the functions specified in the blocks, processes, algorithms, steps, operations, formulas, or computational descriptions.

[0201] It should also be understood that the terms "programming" or "executable program" as used herein refer to one or more instructions that can be executed by one or more computer processors to perform one or more functions described herein. The instructions can be embodied in software, firmware, or a combination of software and firmware. The instructions can be stored in a non-transitory medium local to the device, or can be stored remotely, such as on a server, or all or part of the instructions can be stored locally and remotely. The remotely stored instructions can be downloaded (pushed) to the device by a user initiation, or can be automatically downloaded based on one or more factors.

[0202] It should also be understood that the terms processor, hardware processor, computer processor, central processing unit (CPU), and computer are used synonymously herein to denote a device capable of executing instructions and communicating with an input / output interface and / or peripheral devices, and that the terms processor, hardware processor, computer processor, CPU, and computer are intended to include single or multiple devices, single-core and multi-core devices, and their variants.

[0203] From the description herein, it can be understood that the present disclosure includes multiple embodiments of the present technology, which include but are not limited to the following aspects:

[0204] A device for wireless communication in a network, the device comprising: (a) wireless communication circuitry as a wireless station (STA), the STA operating as a conventional STA or an access point (AP) STA for wireless communication with other wireless stations (STAs) over a wireless local area network (WLAN) by using a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism; (b) a processor coupled to the wireless communication circuitry to operate over the WLAN; (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs; and (d) wherein the instructions, when executed by the processor, perform one or more steps of a wireless communication protocol for the wireless communication circuitry, including: (d)(i) reusing a broadcast target wake time (B-TWT) signaling defined in IEEE 802.11ax to establish a restricted TWT (R-TWT); (d)(ii) indicating within the B-TWT by using bits of a broadcast TWT parameter set field reserved in IEEE 802.11ax to indicate the use of the R-TWT; and (d)(iii) in response to using other bits in a broadcast TWT recommendation field reserved in IEEE 802.11ax, indicating additional settings for a traffic flow specifying the R-TWT.

[0205] An apparatus for wireless communication in a network, the apparatus comprising: (a) wireless communication circuitry as a wireless station (STA), the STA operating as a conventional STA or an access point (AP) STA for wireless communication with other wireless stations (STA) over a wireless local area network (WLAN) by using a carrier sense multiple access / collision avoidance (CSMA / CA) mechanism; (b) a processor coupled to the wireless communication circuitry to operate over the WLAN; (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs; and (d) wherein the instructions, when executed by the processor, perform one or more steps of a wireless communication protocol for the wireless communication circuitry, including: (d)(i) reusing broadcast target wake time (B-TWT) signaling defined in IEEE 802.11ax to establish a restricted TWT (R-TWT); (d)(ii) indicating within the B-TWT by using bits of a broadcast TWT parameter set field reserved in IEEE 802.11ax to indicate the use of the R-TWT; (d)(iii) in response to using other bits in a broadcast TWT recommendation field reserved in IEEE 802.11ax, indicating additional settings for a traffic flow specifying the R-TWT; and (d)(iv) wherein one or more of the traffic flow settings are selected from a traffic flow setting group including the following traffic flow settings: (A) indicating whether to use a silent element to protect the R-TWT, (B) indicating whether the restricted TWT can be extended beyond the end time of its own schedule in the case of no transmission of corresponding traffic at the end of the R-TWT SP, (C) indicating whether the AP is forced to use PSR-based spatial reuse during the restricted TWT SP, (D) indicating whether the AP and R-TWT members can access multiple overlapping R-TWT SPs on different links within the same time period, (E) indicating whether traffic from all SCSs is allowed to be transmitted during the R-TWT SP, (F) indicating whether the members of the R-TWT need to wake up / sleep in response to the broadcast TWT, (G) indicating the amount of traffic information included in the broadcast TWT parameter set field.

[0206] A method for wireless communication in a network, comprising: (a) communicating between a wireless station (STA) and other wireless stations (STA) on a wireless local area network (WLAN) by using a Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) mechanism, the wireless station executing a wireless communication protocol and operating as a regular STA or an access point (AP) STA to perform wireless communication with the other wireless stations; (b) reusing Broadcast Target Wake Time (B-TWT) signaling defined in IEEE 802.11ax to establish a Restricted TWT (R-TWT); (c) indicating within the B-TWT by using bits of a Broadcast TWT parameter set field reserved in IEEE 802.11ax to indicate the use of the R-TWT; and (d) in response to utilizing other bits in a Broadcast TWT recommendation field reserved in IEEE 802.11ax, indicating additional settings for specifying traffic flows of the R-TWT.

[0207] An apparatus for wireless communication in a network, the apparatus comprising: (a) a wireless communication circuit of a wireless station (STA) that operates arbitrarily as a regular STA or an access point (AP) STA for performing wireless communication with other wireless stations (STA) on a wireless local area network (WLAN) by using a Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) mechanism used with a Multi-Link Device (MLD); (b) a processor coupled to the wireless communication circuit to operate on the WLAN; (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs; and (d) wherein the instructions, when executed by the processor, perform one or more steps of a wireless communication protocol for the wireless communication circuit, including: (d)(i) scheduling, by the MLD, multiple overlapping R-TWT SPs; (d)(ii) starting an R-TWT SP on a link if the number of overlapping R-TWT SPs already started on other links has not reached a maximum number; and (d)(iii) canceling an R-TWT SP on a specific link if the number of R-TWT SPs already started on other links has reached the maximum number.

[0208] An apparatus for wireless communication in a network, the apparatus comprising: (a) wireless communication circuitry as a wireless station (STA), the STA operating as a regular STA or an access point (AP) STA for wireless communication with other wireless stations (STA) over a wireless local area network (WLAN) by using a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism; (b) a processor coupled to the wireless communication circuitry to operate over the WLAN; (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs; and (d) wherein the instructions, when executed by the processor, perform one or more steps of a wireless communication protocol for the wireless communication circuitry, including: (d)(i) establishing an R-TWT and scheduling a silent interval, whereby the R-TWT SP end time is aligned with the end time of the silent interval; (d)(ii) having STAs that are not members of the R-TWT enter a silent mode during the silent interval; and (d)(iii) wherein STAs that are members of the R-TWT are not permitted to enter a silent mode during the silent interval.

[0209] An apparatus for wireless communication in a network, the apparatus comprising: (a) wireless communication circuitry as a wireless station (STA), the STA operating as a regular STA or an access point (AP) STA for wireless communication with other wireless stations (STA) over a wireless local area network (WLAN) by using a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism; (b) a processor coupled to the wireless communication circuitry to operate over the WLAN; (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs; and (d) wherein the instructions, when executed by the processor, perform one or more steps of a wireless communication protocol for the wireless communication circuitry, including: (d)(i) sending an R-TWT membership request with specific traffic information transmitted during the R-TWT SP to an associated AP; (d)(ii) wherein acceptance of the R-TWT membership request is determined by the associated AP based on the specific traffic information; and (d)(iii) wherein the associated AP uses the specific traffic information to distinguish traffic matching the specific traffic information from other traffic information.

[0210] An apparatus for wireless communication in a network, the apparatus comprising: (a) wireless communication circuitry acting as a wireless station (STA), the STA operating as a regular STA or an access point (AP) STA for wireless communication with other wireless stations (STAs) over a wireless local area network (WLAN) by using a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism; (b) a processor coupled to the wireless communication circuitry to operate over the WLAN; (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs; and (d) wherein the instructions, when executed by the processor, perform one or more steps of a wireless communication protocol for the wireless communication circuitry, including: (d)(i) scheduling, by the AP, a start time of an R-TWT SP; (d)(ii) starting, by the AP and R-TWT members, the R-TWT SP according to the schedule; and (d)(iii) extending, by the AP and R-TWT members, the R-TWT SP to an extended time if the AP and R-TWT members cannot start the R-TWT SP according to the schedule.

[0211] A wireless communication apparatus for performing transmission of packets, wherein CSMA / CA is applied in the system / apparatus, comprising: (A) the STA reusing the broadcast TWT signaling defined in IEEE 802.11ax to establish a restricted TWT; (b) the STA indicating, in a broadcast TWT recommendation field in a reserved bit of a broadcast TWT parameter set field, that the signaling is for a restricted TWT; and (c) the STA indicating additional settings of the restricted TWT in the broadcast TWT recommendation field.

[0212] A wireless communication apparatus for performing transmission of packets, wherein CSMA / CA is applied in the system / apparatus, comprising: (A) the MLD scheduling multiple overlapping R-TWT SPs; (b) being able to start an R-TWT SP on a link if the number of overlapping R-TWT SPs already started on other links has not reached a maximum number (the overlapping R-TWTs may only represent those serving the same TID or the same SCS or traffic flow); (c) canceling R-TWT SPs on some links if the maximum number of R-TWT SPs has been started on other links.

[0213] A wireless communication apparatus for performing transmission of packets, wherein CSMA / CA is applied in the system / apparatus, comprising: (A) the STA establishing an R-TWT and scheduling a silent interval, whereby the end time of the R-TWT SP is aligned with the end time of the silent interval; (b) STAs that are not members of the R-TWT entering a silent mode during the silent interval; (c) STAs that are members of the R-TWT being able not to enter the silent mode during the silent interval.

[0214] A wireless communication device for performing grouped transmissions, wherein CSMA / CA is applied in the system / device, comprising: (A) the STA sends an R-TWT membership request with specific traffic information to be transmitted during the R-TWT SP; (b) the AP determines whether to accept the R-TWT membership request based on the specific traffic information; (c) the AP uses the specific traffic information to distinguish traffic matching the specific traffic information from other traffic.

[0215] A wireless communication device for performing grouped transmissions, wherein CSMA / CA is applied in the system / device, comprising: (A) the AP schedules the start time of the R-TWT SP; (b) the AP and the R-TWT members attempt to start the R-TWT SP as scheduled; (c) if the AP and the R-TWT members cannot start the R-TWT SP as scheduled, they extend the R-TWT SP.

[0216] The device or method according to any of the foregoing embodiments,

[0217] The device or method according to any of the foregoing embodiments, wherein the STA uses bit 9 (B9) of the request type field in the broadcast TWT parameter set field to indicate whether broadcast TWT signaling is used for restricted TWT (R-TWT).

[0218] The device or method according to any of the foregoing embodiments, wherein the STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate additional settings for the restricted TWT.

[0219] The device or method according to any of the foregoing embodiments, wherein the STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether to use a silent element to protect the R-TWT; and the silent element is used to schedule a silent interval to prevent channel contention from STAs that are not members of the R-TWT SP and to enter a silent mode during the R-TWT SP after receiving a silent element command from the scheduling AP.

[0220] The device or method according to any of the foregoing embodiments, wherein the STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether the restricted TWT can be extended beyond its scheduled end time if the corresponding traffic is not transmitted at the end of the R-TWT SP.

[0221] The apparatus or method according to any of the foregoing embodiments, wherein the STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether the AP is forced to use PSR-based spatial reuse during the restricted TWT SP.

[0222] The apparatus or method according to any of the foregoing embodiments, wherein the PSR-based spatial reuse includes parameterized spatial reuse transmission (PSRT) or parameterized spatial reuse reception (PSRR) physical layer convergence procedure (PLCP) protocol data unit (PPDU) defined by IEEE 802.11ax for spatial reuse.

[0223] The apparatus or method according to any of the foregoing embodiments, wherein the STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether the AP and R-TWT members can access multiple overlapping R-TWT SPs on different links within the same time period.

[0224] The apparatus or method according to any of the foregoing embodiments, wherein the options for multiple overlapping R-TWT SPs are selected from an option group including the following options: (a) only allowing the start of one scheduled overlapping R-TWT SP and canceling the others; and (b) allowing the start of multiple scheduled overlapping R-TWT SPs.

[0225] The apparatus or method according to any of the foregoing embodiments, wherein the STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether traffic from all SCSs is allowed to be transmitted during the R-TWT SP.

[0226] The apparatus or method according to any of the foregoing embodiments, wherein the STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether the members of the R-TWT need to perform the wake-up and sleep indicated by the broadcast TWT.

[0227] The apparatus or method according to any of the foregoing embodiments, wherein the STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate the amount of traffic information included in the broadcast TWT parameter set field.

[0228] The apparatus or method according to any of the foregoing embodiments, wherein the traffic information is selected from the group of traffic information including a traffic specification (TSPEC), a flow classification service identifier (SCSID), and a traffic identifier (TID).

[0229] The apparatus or method according to any of the foregoing embodiments, wherein the STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether to allow R-TWT members to perform channel contention outside the R-TWT SP.

[0230] The apparatus or method according to any of the foregoing embodiments, wherein the STA uses bit 9 (B9) of the request type field in the broadcast TWT parameter set field to indicate whether the broadcast TWT signaling is used for a restricted TWT (R-TWT).

[0231] The apparatus or method according to any of the foregoing embodiments, wherein overlapping R-TWTs may only represent those serving the same TID or the same SCS or traffic flow.

[0232] The apparatus or method according to any of the foregoing embodiments, wherein the R-TWT SP may end earlier than when it is scheduled.

[0233] The apparatus or method according to any of the foregoing embodiments, wherein the STA may send a frame to indicate the start of the R-TWT SP.

[0234] The apparatus or method according to any of the foregoing embodiments, wherein an STA that is a member of a cancelled R-TWT SP is not allowed to access the channel until the R-TWT SP on another link ends.

[0235] The apparatus or method according to any of the foregoing embodiments, wherein the STA on the link where the R-TWT SP is cancelled follows EDCA or CSMA / CA to contend for the channel.

[0236] The apparatus or method according to any of the foregoing embodiments, wherein the number of overlapping R-TWT SPs that can start on different links is limited.

[0237] The apparatus or method according to any of the foregoing embodiments, wherein the R-TWT member sends a frame to indicate the end of the R-TWT SP.

[0238] The apparatus or method according to any of the foregoing embodiments, wherein the STA that receives a frame indicating the end of the R-TWT SP may start contending for the channel.

[0239] The apparatus or method according to any of the foregoing embodiments further includes transmitting a frame to indicate the end of the current R-TWT SP or the end of the silent interval.

[0240] The apparatus or method according to any of the foregoing embodiments, wherein a silent interval longer than the R-TWT SP duration cannot be scheduled.

[0241] The apparatus or method according to any of the foregoing embodiments further includes transmitting a silent element to notify other STAs of the silent interval scheduling.

[0242] The apparatus or method according to any of the foregoing embodiments, wherein the specific information is selected from the group of information including SCS ID, TID, and TSPEC.

[0243] The apparatus or method according to any of the foregoing embodiments further includes: if the associated AP determines that the R-TWT SP cannot meet the transmission requirements of specific traffic, rejecting the R-TWT membership request.

[0244] The apparatus or method according to any of the foregoing embodiments further includes: if the total time required to transmit specific traffic exceeds the upper limit of the total time of all R-TWT SPs that the associated AP is allowed to schedule, rejecting the R-TWT membership request.

[0245] The apparatus or method according to any of the foregoing embodiments further includes: if the total time required to transmit specific traffic exceeds the upper limit of the total time of all R-TWT SPs that the MLD to which the AP belongs is allowed to schedule on all links, rejecting the R-TWT membership request.

[0246] The apparatus or method according to any of the foregoing embodiments, wherein the same specific traffic is not accepted by two different R-TWTs of an AP on one link.

[0247] The apparatus or method according to any of the foregoing embodiments, wherein the same specific traffic cannot be accepted by two different R-TWTs of the AP MLD on all links.

[0248] The apparatus or method according to any of the foregoing embodiments, wherein the extended time of the R-TWT SP cannot exceed the TXOP limit or a determined fraction of the TXOP limit.

[0249] The apparatus or method according to any of the foregoing embodiments, wherein the actual R-TWT SP duration cannot exceed the TXOP limit or a determined fraction of the TXOP limit.

[0250] The apparatus or method according to any of the foregoing embodiments, wherein the actual R-TWT SP duration cannot exceed the scheduled R-TWT SP time.

[0251] The apparatus or method according to any of the foregoing embodiments, wherein the extended time of the R-TWT SP cannot exceed the next target beacon transmission time.

[0252] The apparatus or method according to any of the foregoing embodiments, wherein when an AP or STA that is a member of an R-TWT obtains a TXOP during a scheduled R-TWT SP, in the case where the TXOP extends beyond the end time of the scheduled R-TWT SP, it may extend the R-TWT SP; and wherein the R-TWT SP is extended to the end time of the TXOP.

[0253] The apparatus or method according to any of the foregoing embodiments, wherein when an AP or STA that is a member of an R-TWT SP starts PPDU transmission during a scheduled R-TWT SP and the PPDU duration and the requested transmission exceed the end time of the scheduled R-TWT SP, it may extend the R-TWT.

[0254] The apparatus or method according to any of the foregoing embodiments, wherein the R-TWT SP is extended to the end time of the PPDU transmission and its requested transmission.

[0255] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use B9 of the request type field in the broadcast TWT parameter set field to indicate whether the broadcast TWT signaling is used for a restricted TWT.

[0256] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use one bit between B7 and B8 or B15 of the request type field in the broadcast TWT parameter set field to indicate an additional setting of the restricted TWT.

[0257] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use one bit between B7 and B8 or B15 of the request type field in the broadcast TWT parameter set field to indicate whether a silent element is used for a restricted TWT.

[0258] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use one bit between B7 and B8 or B15 of the request type field in the broadcast TWT parameter set field to indicate whether the restricted TWT can be extended in the case where there is no transmission of corresponding traffic at the end of the R-TWT SP.

[0259] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use one bit between B7 and B8 or B15 of the request type field in the broadcast TWT parameter set field to indicate whether the AP is forced to use PSR-based spatial reuse during the restricted TWT SP.

[0260] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use one bit between B7 and B8 or B15 of the request type field in the broadcast TWT parameter set field to indicate whether the AP and the R-TWT members can access multiple R-TWT SPs on different links within the same time period.

[0261] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use one bit between B7 and B8 or B15 of the request type field in the broadcast TWT parameter set field to indicate whether traffic from all SCSs is allowed to be transmitted during the R-TWT SP.

[0262] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use one bit between B7 and B8 or B15 of the request type field in the broadcast TWT parameter set field to indicate whether the members of the R-TWT need to wake up and sleep according to the broadcast TWT.

[0263] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use one bit between B7 and B8 or B15 of the request type field in the broadcast TWT parameter set field to indicate whether there is one or more traffic information, such as TSPEC, SCSID, or TID, included in the broadcast TWT parameter set field.

[0264] The apparatus or method according to any of the foregoing embodiments, wherein the STA may use one bit between B7 and B8 or B15 of the request type field in the broadcast TWT parameter set field to indicate whether the R-TWT members are allowed to contend for the channel outside the R-TWT SP.

[0265] The apparatus or method according to any of the foregoing embodiments, wherein the R-TWT SP may end earlier than it is scheduled.

[0266] The apparatus or method according to any of the foregoing embodiments, wherein the STA may send a frame to indicate the start of the R-TWT SP.

[0267] The apparatus or method according to any of the foregoing embodiments, wherein a STA that is a member of a cancelled R-TWT SP is not allowed to access the channel until the R-TWT SP on other links ends.

[0268] The apparatus or method according to any of the foregoing embodiments, wherein all STAs on the link where the R-TWT SP is cancelled follow EDCA or CSMA / CA to contend for the channel.

[0269] The apparatus or method according to any of the foregoing embodiments, wherein the number of overlapping R-TWT SPs that can start on different links is limited.

[0270] The apparatus or method according to any of the foregoing embodiments, wherein an R-TWT member may send a frame to indicate the end of the R-TWT SP.

[0271] The apparatus or method according to any of the foregoing embodiments, wherein an STA that receives a frame indicating the end of the R-TWT SP may start contending for the channel.

[0272] The apparatus or method according to any of the foregoing embodiments, wherein an STA may send a frame such as CF-End to indicate the end of the current R-TWT SP or the end of the silent interval.

[0273] The apparatus or method according to any of the foregoing embodiments, wherein an STA cannot schedule beyond the silent interval of the R-TWT SP.

[0274] The apparatus or method according to any of the foregoing embodiments, wherein an STA may send a silent element to notify other STAs of the silent interval scheduling.

[0275] The apparatus or method according to any of the foregoing embodiments, wherein the specific information includes the SCSID.

[0276] The apparatus or method according to any of the foregoing embodiments, wherein the specific information includes the TID.

[0277] The apparatus or method according to any of the foregoing embodiments, wherein the specific information includes the TSPEC.

[0278] The apparatus or method according to any of the foregoing embodiments, wherein if the R-TWT SP cannot meet the transmission requirements of specific traffic, the AP may reject the R-TWT membership request.

[0279] The apparatus or method according to any of the foregoing embodiments, wherein if the total time required to transmit specific traffic exceeds the upper limit of the total time of all R-TWT SPs that the AP is allowed to schedule (or that the scheduling AP MLD can schedule on all links), the AP may reject the R-TWT membership request.

[0280] The apparatus or method according to any of the foregoing embodiments, wherein the AP may reject an R-TWT membership request if the total time required to transmit a specific traffic exceeds an upper limit of the total time of all R-TWT SPs scheduled by the MLD to which the AP belongs on all links.

[0281] The apparatus or method according to any of the foregoing embodiments, wherein the same specific traffic cannot be accepted by two different R-TWTs of an AP on one link.

[0282] The apparatus or method according to any of the foregoing embodiments, wherein the same specific traffic cannot be accepted by two different R-TWTs of the AP MLDs on all links.

[0283] The apparatus or method according to any of the foregoing embodiments, wherein the extended time of the R-TWT SP cannot be longer than the TXOP limit.

[0284] The apparatus or method according to any of the foregoing embodiments, wherein the extended time of the R-TWT SP cannot be longer than a given fraction (e.g., 50%) of the TXOP limit.

[0285] The apparatus or method according to any of the foregoing embodiments, wherein the actual R-TWT SP duration cannot be longer than the TXOP limit.

[0286] The apparatus or method according to any of the foregoing embodiments, wherein the actual R-TWT SP duration cannot be longer than a fraction of the TXOP limit.

[0287] The apparatus or method according to any of the foregoing embodiments, wherein the actual R-TWT SP duration cannot be longer than the scheduled R-TWT SP time.

[0288] The apparatus or method according to any of the foregoing embodiments, wherein the extended time of the R-TWT SP cannot exceed the next target beacon transmission time.

[0289] The apparatus or method according to any of the foregoing embodiments, wherein an AP or STA that is a member of an R-TWT SP may extend the R-TWT when it obtains a TXOP during the scheduled R-TWT SP and the TXOP duration exceeds the end time of the scheduled R-TWT SP. The R-TWT SP is extended to the end time of the TXOP.

[0290] The apparatus or method according to any of the foregoing embodiments, wherein an AP or STA that is a member of an R-TWT SP may extend the R-TWT when it starts a PPDU transmission during a scheduled R-TWT SP and the PPDU duration and the requested transmission exceed the end time of the scheduled R-TWT SP. The R-TWT SP is extended to the end time of the PPDU transmission and its requested transmission.

[0291] As used herein, the term "embodiment" is intended to include, but not be limited to, examples, instances, or other forms of implementing the technologies described herein.

[0292] As used herein, unless the context clearly dictates otherwise, the singular terms "a," "an," and "the" may include plural referents. The object in the singular form does not mean "one and only one" unless explicitly stated, but rather "one or more."

[0293] Phrase structures in this disclosure, such as "A, B, and / or C," describe situations where any of A, B, or C may exist arbitrarily, or any combination of item A, item B, and item C. Phrase structures indicating "at least one" of a set of elements, such as the following, indicate that at least one of these sets of elements exists, which includes any possible applicable combinations of the listed elements.

[0294] References in this disclosure to "an embodiment," "at least one embodiment," or similar language of embodiments indicate that a particular feature, structure, or characteristic described in connection with the described embodiment is included in at least one embodiment of this disclosure. Thus, these different embodiment phrases do not necessarily all refer to the same embodiment or to a particular embodiment different from all other embodiments being described. The language of embodiments should be interpreted to mean that, in one or more embodiments of the disclosed apparatus, system, or method, the particular features, structures, or characteristics of a given embodiment may be combined in any suitable manner.

[0295] As used herein, the term "set" refers to a collection of one or more objects. Thus, for example, a set of objects may include a single object or multiple objects.

[0296] Relational terms such as first and second, and top and bottom, may be used only to distinguish one entity or action from another entity or action, and do not necessarily require or imply any actual such relationship or order between such entities or actions.

[0297] The terms "comprising", "including", "having", "containing" or other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or apparatus that comprises, has, includes or contains a list of elements not only includes those elements, but may also include other elements not expressly listed or inherent to such process, method, article or apparatus. Without further limitation, an element preceded by "comprising...", "having...", "including...", or "containing..." does not preclude the presence of additional identical elements in the process, method, article or apparatus that comprises, has, includes or contains the element.

[0298] As used herein, the terms "approximate", "substantially", "essentially", "substantively" and "about", or any other version thereof, are used to describe and account for minor variations. When used in connection with an event or circumstance, these terms can refer to instances where the event or circumstance occurs precisely, as well as instances where the event or circumstance occurs nearly. When used in connection with a numerical value, these terms can refer to a range of variation of plus or minus 10% of the numerical value, such as plus or minus 5%, plus or minus 4%, plus or minus 3%, plus or minus 2%, plus or minus 1%, plus or minus 0.5%, plus or minus 0.1% or plus or minus 0.05%. For example, "substantially" aligned can refer to a range of angular variation of plus or minus 10°, such as plus or minus 5°, plus or minus 4°, plus or minus 3°, plus or minus 2°, plus or minus 1°, plus or minus 0.5°, plus or minus 0.1% or plus or minus 0.05°.

[0299] In addition, quantities, ratios and other numerical values may sometimes be presented in a range format. It should be understood that this range format is used for convenience and brevity and should be interpreted flexibly as including the numerical values expressly designated as the limits of the range, but also including all individual numerical values or sub-ranges subsumed within that range as if each numerical value and sub-range were expressly designated. For example, a ratio in the range of about 1 to about 200 should be understood to include the expressly recited limits of about 1 and about 200, but also individual ratios such as about 2, about 3 and about 4, and sub-ranges such as about 10 to about 50 and about 20 to about 100.

[0300] The term "coupled" as used herein is defined as connected, although not necessarily directly, and not necessarily mechanically. An apparatus or structure that is "configured" in a certain way is configured at least in that way, but may also be configured in ways not listed.

[0301] Benefits, advantages, solutions to problems, and any element that may cause any benefit, advantage or solution to occur or become more apparent should not be construed as critical, required or essential features or elements of the technology described herein or in any or all of the claims.

[0302] In addition, in the above disclosure, for the sake of simplicity of disclosure, various features may be grouped together in various embodiments. This disclosed method should not be construed as reflecting an intention that the claimed embodiments require more features than those expressly recited in each claim. The subject matter of the present invention may lie in less than all of the features of a single disclosed embodiment.

[0303] The abstract of the present disclosure is provided to enable the reader to quickly confirm the nature of the technical disclosure. There is an understanding that, when it is submitted, it is not to be used to interpret or limit the scope or meaning of the claims.

[0304] It should be understood that the practice in some jurisdictions may require the deletion of one or more portions of the disclosure after the filing of the application. Accordingly, the reader should refer to the filed application for the original content of this disclosure. Any deletion of the disclosure should not be construed as a disclaimer, forfeiture, or dedication to the public of any subject matter of the originally filed application.

[0305] The following claims are hereby incorporated into this disclosure, each claim as a separate subject matter claimed on its own.

[0306] Although the description herein contains many details, these details should not be construed as limiting the scope of the disclosure, but rather as providing illustrations of some of the currently preferred embodiments. Accordingly, it should be understood that the scope of the disclosure fully encompasses other embodiments that may become apparent to those skilled in the art.

[0307] All structural and functional equivalents of the elements of the disclosed embodiments known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by these claims. Also, no element, component, or method step in this disclosure is intended to be dedicated to the public, regardless of whether the element, component, or method step is expressly recited in the claims. An element shall not be construed as a "means-plus-function" element unless the claim element herein is expressly recited using the phrase "means for" ... "for". Nor shall any such element be construed as a "step-plus-function" element unless the claim element herein is expressly recited using the phrase "step for...".

Claims

1. An apparatus for wireless communication in a network, the apparatus comprising: (a) wireless communication circuitry as a wireless station (STA), the STA operating as a conventional STA or an access point (AP) STA for wireless communication with other wireless stations (STAs) over a wireless local area network (WLAN) by using a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism; (b) a processor coupled to the wireless communication circuitry to operate over the WLAN; (c) non-transitory memory storing instructions executable by the processor for communicating with other STAs; and (d) wherein the instructions, when executed by the processor, perform steps for a wireless communication protocol for the wireless communication circuitry, including: (i) reusing broadcast target wake time (B-TWT) signaling defined in IEEE 802.11ax to establish a restricted TWT (R-TWT); (ii) indicating, within the B-TWT, by using bits of a broadcast TWT parameter set field reserved in IEEE 802.11ax, an indication of the use of the R-TWT; and (iii) in response to using other bits in a broadcast TWT recommendation field reserved in IEEE 802.11ax, indicating additional settings for a traffic flow specifying the R-TWT.

2. The device according to claim 1, wherein The STA uses bit 9 (B9) of a request type field in the broadcast TWT parameter set field to indicate whether the broadcast TWT signaling is used for a restricted TWT (R-TWT).

3. The device according to claim 1, wherein, The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of a request type field in the broadcast TWT parameter set field to indicate additional settings for the restricted TWT.

4. The apparatus according to claim 1: Among them, The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of a request type field in the broadcast TWT parameter set field to indicate whether to use a silent element to protect the R-TWT; and wherein the silent element is used to schedule a silent interval to prevent channel contention from STAs that are not members of the R-TWT SP and enter a silent mode during the R-TWT SP after receiving a silent element command from a scheduling AP.

5. The device according to claim 1, wherein The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of a request type field in the broadcast TWT parameter set field to indicate whether the restricted TWT can be extended beyond its own scheduled end time in the case where no corresponding traffic is transmitted at the end of the R-TWT SP.

6. The device according to claim 1, wherein The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of a request type field in the broadcast TWT parameter set field to indicate whether the AP is forced to use PSR-based spatial reuse during the restricted TWT SP.

7. The device according to claim 6, wherein, The PSR-based spatial reuse includes a parameterized spatial reuse transmission (PSRT) or parameterized spatial reuse reception (PSRR) physical layer convergence procedure (PLCP) protocol data unit (PPDU) for spatial reuse defined in IEEE 802.11ax.

8. The device according to claim 1, wherein, The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether the AP and R-TWT members can access multiple overlapping R-TWT SPs on different links within the same time period.

9. The device according to claim 8, wherein, Options for multiple overlapping R-TWT SPs are selected from an option group including the following options: (a) only allowing the start of one scheduled overlapping R-TWT SP and canceling other overlapping R-TWT SPs; and (b) allowing the start of multiple scheduled overlapping R-TWT SPs.

10. The device according to claim 1, wherein, The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether traffic from all SCSs is allowed to be transmitted during the R-TWT SP.

11. The device according to claim 1, wherein The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether the members of the R-TWT need to perform the wake-up and sleep indicated in the broadcast TWT.

12. The device according to claim 1, wherein The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate the amount of traffic information included in the broadcast TWT parameter set field.

13. The apparatus according to claim 12, wherein, The traffic information is selected from the group of traffic information including traffic specification (TSPEC), flow classification service identification (SCSID), and traffic identifier (TID).

14. The device according to claim 1, wherein The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of the request type field in the broadcast TWT parameter set field to indicate whether R-TWT members are allowed to perform channel contention outside the R-TWT SP.

15. An apparatus for wireless communication in a network, the apparatus comprising: (a) wireless communication circuitry as a wireless station (STA), the STA operating as a conventional STA or an access point (AP) STA for wirelessly communicating with other wireless stations (STA) on a wireless local area network (WLAN) by using a carrier sense multiple access / collision avoidance (CSMA / CA) mechanism; (b) a processor coupled to the wireless communication circuitry to operate on the WLAN; (c) non-transitory memory storing instructions executable by the processor for communicating with other STAs; and (d) wherein, when executed by the processor, the instructions perform steps of a wireless communication protocol for the wireless communication circuitry, including: (i) reusing the broadcast target wake-up time (B-TWT) signaling defined in IEEE 802.11ax to establish a restricted TWT (R-TWT); (ii) within the B-TWT, it is indicated by using bits of a broadcast TWT parameter set field reserved in IEEE 802.11ax to indicate the use of R-TWT; and (iii) in response to using other bits in a broadcast TWT recommendation field reserved in IEEE 802.11ax, indicating additional settings for specifying a traffic flow of R-TWT; and (iv) wherein one or more of the traffic flow settings are selected from a group of traffic flow settings including the following traffic flow settings: (A) indicating whether to use a silent element to protect R-TWT, (B) indicating whether a restricted TWT can be extended beyond the end time of its own schedule when there is no transmission of corresponding traffic at the end of the R-TWT SP, (C) indicating whether an AP is forced to use PSR-based spatial reuse during the restricted TWT SP, (D) indicating whether an AP and R-TWT members can access multiple overlapping R-TWT SPs on different links within the same time period, (E) indicating whether traffic from all SCSs is allowed to be transmitted during the R-TWT SP, (F) indicating whether members of R-TWT need to wake up / sleep in response to a broadcast TWT, (G) indicating the amount of traffic information included in the broadcast TWT parameter set field.

16. The device according to claim 15, wherein, The STA uses bit 9 (B9) of a request type field in the broadcast TWT parameter set field to indicate whether the broadcast TWT signaling is used for a restricted TWT (R-TWT).

17. The device according to claim 16, wherein, The STA uses one bit between bit 7 (B7) and bit 8 (B8) or bit 15 (B15) of a request type field in the broadcast TWT parameter set field to indicate additional settings of the restricted TWT.

18. The apparatus according to claim 15, wherein The traffic information is selected from a group of traffic information including a traffic specification (TSPEC), a flow classification service identifier (SCSID), and a traffic identifier (TID).

19. A method for wireless communication in a network, comprising: (a) communicating between a wireless station (STA) and other wireless stations (STA) over a wireless local area network (WLAN) by using a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism, the wireless station implementing a wireless communication protocol and operating as a regular STA or an access point (AP) STA to perform wireless communication with the other wireless stations; (b) reusing a broadcast target wake time (B-TWT) signaling defined in IEEE 802.11ax to establish a restricted TWT (R-TWT); (c) within the B-TWT, it is indicated by using bits of a broadcast TWT parameter set field reserved in IEEE 802.11ax to indicate the use of R-TWT; and (d) in response to using other bits in a broadcast TWT recommendation field reserved in IEEE 802.11ax, indicating additional settings for specifying a traffic flow of R-TWT.

20. The method according to claim 19, wherein The STA uses bit 9 (B9) of a request type field in the broadcast TWT parameter set field to indicate whether the broadcast TWT signaling is used for a restricted TWT (R-TWT).

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