Method for performing preemption management in wireless communication system and related device

Abstract

A method and related device for performing preemption management in a wireless communication system, wherein a non-access point working site (non-AP STA) device is wirelessly connected to a first access point (AP) device. The method may comprise: executing, by the first AP device, a client preemption indication in at least one transmission behavior at the beginning of a transmission period to indicate that the non-AP STA device is a preemption client and should be kept awakened in a preemption period within the transmission period; wherein the preemption period reserves for transmitting delay-sensitive traffic to the non-AP STA device.

Description

[0001] Cross-referencing

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 504,468, filed May 26, 2023, the contents of which are incorporated herein by reference. [Technical Field]

[0003] This invention relates to communication control, and more specifically, to a method for performing preemption management in a wireless communication system, and related devices, such as wireless transceiver devices (e.g., access point (AP) devices or workstation (STA) devices) in the wireless communication system. [Background Technology]

[0004] According to relevant technologies, AP devices can be configured to transmit various data to one or more STA devices. When delay-sensitive traffic arrives at the AP device's Media Access Control (MAC) circuitry, the AP device's Physical Layer (PHY) circuitry may be transmitting a Physical Layer Protocol Data Unit (PPDU), which may take several milliseconds (ms). Until the PPDU transmission is complete, the PHY circuitry typically needs to perform another Enhanced Distributed Channel Access (EDCA) process to obtain channel access for the delay-sensitive traffic, thus introducing further delay. Some suggestions have been proposed in relevant technologies to attempt to correct this problem, but these may introduce further issues, such as side effects. Therefore, a novel approach and related architecture are needed to address these issues without introducing any side effects or in a way that makes it unlikely that side effects will be introduced. [Summary of the Invention]

[0005] The objective of this invention is to provide a method for performing preemption management in a wireless communication system, and related devices, such as wireless transceiver devices (e.g., one or more AP devices and one or more non-access point (non-AP) STA devices), to solve the above-mentioned problems.

[0006] At least one embodiment of the present invention provides a method for performing preemption management in a wireless communication system, wherein a non-AP STA device is wirelessly connected to a first AP device. The method may include: the first AP device performing a preemption client indication during at least one transmission action at the beginning of a transmission cycle to indicate that the non-AP STA device is a preemption client and should remain awake during a preemption period within the transmission cycle, wherein the preemption period may be reserved for transmitting latency-sensitive traffic to the non-AP STA device. For example, in response to receiving the preemption client indication, the non-AP STA device may be scheduled to remain awake during the preemption period and prepare for any downlink (DL) traffic or any uplink (UL) trigger. According to some embodiments, the preemption client indication may include a candidate preemption client list for recording at least one candidate preemption client suitable for the latency-sensitive traffic transmission, wherein the at least one candidate preemption client may include the non-AP STA device. Furthermore, this preemption management is applicable to either the Transmission Opportunity (TXOP) level or the PPDU level to enhance overall performance.

[0007] At least one embodiment of the present invention provides an access point (AP) device for performing preemption management in the aforementioned wireless communication system, wherein the AP device may be one of a plurality of devices in the wireless communication system. The AP device may include a processing circuit arranged to control the operation of the AP device. The AP device may also include at least one communication control circuit coupled to the processing circuit and arranged to perform communication control, wherein the at least one communication control circuit is arranged to wirelessly operate with at least one other device among the plurality of devices in the wireless communication system for use by the AP device. For example, a non-AP STA device among the at least one other device is wirelessly connected to the AP device. Furthermore, the AP device may be arranged to perform a preemption client indication in at least one transmission action at the beginning of a transmission cycle to indicate that the non-AP STA device is a preemption client and should remain awake during the preemption period within the transmission cycle, wherein the preemption period may be reserved for transmitting latency-sensitive traffic to the non-AP STA device.

[0008] At least one embodiment of the present invention provides a non-AP STA device for performing preemption management in the aforementioned wireless communication system, wherein the non-AP STA device may be one of a plurality of devices in the wireless communication system. The non-AP STA device may include a processing circuit arranged to control the operation of the non-AP STA device. The non-AP STA device may also include at least one communication control circuit coupled to the processing circuit and arranged to perform communication control, wherein the at least one communication control circuit is arranged to wirelessly operate with at least one other device among the plurality of devices in the wireless communication system for use by the non-AP STA device. For example, the non-AP STA device is wirelessly connected to a first AP device among the at least one other device. Furthermore, the non-AP STA device may be arranged to receive a preemption client indication in at least one transmission action at the beginning of a transmission cycle, indicating that the non-AP STA device is a preemption client and should remain awake during a preemption period within the transmission cycle, wherein the preemption period may be reserved for transmitting latency-sensitive traffic to the non-AP STA device; and in response to receiving the preemption client indication, the non-AP STA device may be arranged to remain awake during the preemption period and prepare for any DL traffic or any UL trigger.

[0009] One advantage of this invention is that, with appropriate design, the method and related devices of this invention, such as wireless transceiver devices (e.g., one or more AP devices and one or more non-AP STA devices), can efficiently perform communication operations by means of preemption. More specifically, by using a preemption client indication carrying a list of candidate preemption clients to notify all candidate preemption clients in the candidate preemption client list that they should remain awake during the preemption period, thereby enhancing overall performance. Furthermore, the method and related devices of this invention can solve related technical problems without introducing any side effects or in a manner unlikely to introduce side effects.

[0010] These and other objectives of the present invention will undoubtedly become apparent to those skilled in the art upon reading the preferred embodiments described below in detail. [Attached Image Description]

[0011] Figure 1 This is a schematic diagram of a wireless communication system according to an embodiment of the present invention.

[0012] Figure 2 Multiple DL PPDU types relating to PPDU preemption control schemes according to embodiments of the present invention are illustrated in several sub-figures (a), (b) and (c).

[0013] Figure 3This paper describes a target client control scheme for performing a preemption management method in a wireless communication system according to an embodiment of the present invention.

[0014] Figure 4 The PPDU-level control scheme of the method according to an embodiment of the present invention is described.

[0015] Figure 5 A PPDU-level control scheme according to another embodiment of the present invention is described.

[0016] Figure 6 A PPDU-level control scheme according to another embodiment of the present invention is described.

[0017] Figure 7 A TXOP-level control scheme for the method according to an embodiment of the present invention is described.

[0018] Figure 8 The workflow of the method according to an embodiment of the present invention is described.

Detailed Implementation Methods

[0019] Certain terms are used in the following description and claims, referring to specific components. As those skilled in the art will understand, electronic device manufacturers may use different names to refer to components. This document is not intended to distinguish between components with different names but identical functions. In the following description and claims, the terms "comprising" and "including" are used in an open-ended manner and should therefore be interpreted as "including, but not limited to...". Furthermore, the term "coupled" is intended to indicate an indirect or direct electrical connection. Thus, if one device is coupled to another device, the connection can be a direct electrical connection or an indirect electrical connection via other devices and connections.

[0020] Figure 1This is a schematic diagram of a wireless communication system 100 according to an embodiment of the present invention. For better understanding, the wireless communication system 100 and any wireless transceiver device #m of the plurality of wireless transceiver devices #1… and #M may be compatible with or backward compatible with one or more versions of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, but the invention is not limited thereto. Regarding the plurality of wireless transceiver devices #1… and #M in the wireless communication system 100, one of the wireless transceiver devices may be implemented as an AP device 110, and another transceiver device may be implemented as a non-AP STA device 120, but the invention is not limited thereto. For example, two or more of the plurality of wireless transceiver devices #1… and #M may be implemented as multiple AP devices {110}. In some examples, two or more of the plurality of wireless transceiver devices #1… and #M may be implemented as multiple AP devices {110}, and / or two or more other wireless transceiver devices #1… and #M may be implemented as multiple non-AP STA devices {120}.

[0021] like Figure 1 As shown, AP device 110 may include processing circuitry 112, at least one communication control circuit (e.g., one or more communication control circuits), collectively referred to as communication control circuitry 114, and at least one antenna (e.g., one or more antennas) of communication control circuitry 114. Non-AP STA device 120 may include processing circuitry 122, at least one communication control circuit (e.g., one or more communication control circuits), collectively referred to as communication control circuitry 124, and at least one antenna (e.g., one or more antennas) of communication control circuitry 124. Figure 1 In the illustrated architecture, processing circuitry 112 can be configured to control the operation of AP device 110, and communication control circuitry 114 can be configured to perform communication control, more specifically, to perform wireless communication operations with the network (or at least one other device, such as non-AP STA device 120) for use by AP device 110. Furthermore, processing circuitry 122 can be configured to control the operation of non-AP STA device 120, and communication control circuitry 124 can be configured to perform communication control, more specifically, to perform wireless communication operations with the network (or at least one other device, such as AP device 110) for use by non-AP STA device 120.

[0022] According to some embodiments, the processing circuit 112 can be implemented using at least one processor / microprocessor, at least one random access memory (RAM), at least one bus, etc., and the communication control circuit 114 can be implemented using at least one wireless network control circuit and at least one wired network control circuit, but the invention is not limited thereto. Examples of AP devices 110 may include, but are not limited to, Wi-Fi routers. Furthermore, the processing circuit 122 can be implemented using at least one processor / microprocessor, at least one RAM, at least one bus, etc., and the communication control circuit 124 can be implemented using at least one wireless network control circuit, but the invention is not limited thereto. Examples of non-AP STA devices 120 may include, but are not limited to, multifunction mobile phones, laptops, all-in-one computers, and wearable devices.

[0023] Figure 2 The diagram illustrates multiple downlink (DL) PPDU types involved in a PPDU preemption control scheme according to an embodiment of the present invention, shown in several sub-graphs (a), (b), and (c), where PPDUs 210A, 210B, and 210C may belong to DL PPDU type 1, DL PPDU type 2, and DL PPDU type 3, respectively. For better understanding, it is assumed that one or more functions of the wireless communication system 100 may be temporarily disabled to allow the AP device 110 and non-AP STA devices 120 to operate according to the PPDU preemption control scheme, but the invention is not limited thereto. Based on the PPDU preemption control scheme, a wireless transceiver device #m (e.g., AP device 110) can perform preemption to pre-allocate certain portions of the PPDU (e.g., ...). Figure 2 The PPDU 210A shown in sub-figure (a), particularly the long PPDU, is designed so that pre-allocated resources can be used for transmission if any delay-sensitive traffic (e.g., low-latency data for the target STA device, such as non-AP STA device 120) arrives. However, if no such traffic arrives before the preemption period, the pre-allocated resources may be wasted. Taking PPDU 210A as an example, the data portion of the PPDU can be implemented in the form of resource units (RUs), and for multiple users, multiple-input multiple-output (MIMO) can be used to multiply the wireless link capacity through multiple transmit and receive antennas. More specifically, the time axis can be displayed horizontally to indicate the existence of multiple time-related fields, and different portions displayed vertically can correspond to different RUs, but the invention is not limited thereto. Furthermore, the target STA device can be implemented as STA STA(N), which for simplicity can be referred to as "STA N", and other STA devices can be implemented as STA STA(1), STA(2), etc., which for simplicity can be referred to as STA STA1, STA2, etc.

[0024] Based on the PPDU preemption control scheme, the preemption portion of the PPDU may have several design possibilities. For example, the PPDU data may be for a single user (SU). Regarding the PPDU 210A shown in sub-diagram (a), multiple fields may include “Preamble and SIG” fields, such as the preamble field / subfield and the signal (SIG) field / subfield, and further include the data fields for STA STA1 and STA2, as well as the preemption field for STA N (labeled as “PPDU data for STA1”, “PPDU data for STA2”, and “Preemption for STA N” respectively for ease of understanding). Regarding the PPDUs 210B and 210C shown in sub-diagrams (b) and (c) respectively, multiple fields may further include “Midamble and SIG” fields, such as the intermediate preamble field / subfield and the signal (SIG) field / subfield, and more specifically, when necessary, include the data field for STA STA3 (labeled as “PPDU data for STA3” for ease of understanding). If the preamble and SIG already provide sufficient information for STA N to decode the data portion in preemption, the SIG in the intermediate preamble and SIG can be optional. Multiple intermediate preamble and SIG instances may exist, and the intermediate preamble and SIG can carry an indication of whether it is the last intermediate preamble and SIG. For example, this indication can be achieved with a more intermediate preamble bit (e.g., More_Midamble). When the more intermediate preamble bit equals the first predetermined value (e.g., More_Midamble = 1), this may indicate that at least one more intermediate preamble and SIG follows in this PPDU. When the more intermediate preamble bit equals another predetermined value (e.g., More_Midamble = 0), this may indicate that the current intermediate preamble and SIG is the last in this PPDU. Furthermore, if the more intermediate preamble bit equals the first predetermined value (e.g., More_Midamble = 1), the intermediate preamble and SIG carrying that bit can provide signaling for subsequent portions of the PPDU in the same manner as the preamble and SIG. In both cases of subgraphs (b) and (c), if the intermediate preamble and SIG still carry the potential preemption of STA N during the preemption period, STA N may continue to wait and remain awake; otherwise, STA N may enter power saving (PS) mode (or PS state).

[0025] For example, when AP device 110 starts transmitting PPDU 210A, STA N needs to track STA1's PPDU data until the preemption portion. If no data arrives at STA N before preemption, the preemption (or its RU) will be wasted. When AP device 110 starts transmitting PPDU 210B, STA N can wait until the midamble and check the midamble and SIG for subsequent resource allocation. The midamble typically consumes some resources but provides flexibility in rescheduling resources. If no data arrives at STA N before preemption, resources can be reallocated. When AP device 110 starts transmitting PPDU 210C, STA N can wait until the midamble and check the midamble and SIG for subsequent resource allocation. The midamble typically consumes some resources but provides flexibility in rescheduling resources. As shown in sub-figure (c), the midamble only occupies a portion of the PPDU bandwidth. If no data arrives at STA N before preemption, resources can be reallocated. In addition, Midamble content may include short training fields (STF) and long training fields (LTF) for receiver synchronization and channel estimation, while SIG content may include the associated identifier (ID) (or "AID") of the STA that is assigned an RU for DL ​​transmission, RU allocation and channel bandwidth information, PPDU length information, permitted operations during PPDU such as spatial multiplexing (SR), and other transmit (TX) vector (or TXVECTOR) and receive (RX) vector (or RXVECTOR) information, as well as basic service set (BSS) color.

[0026] AP device 110, operating according to a PPDU preemption control scheme, can provide the client's AID in the SIG so that if the target client (e.g., STA N) is not listed in the SIG, the target client can enter PS mode, thereby skipping the PPDU (e.g., the preemptive portion of the PPDU carrying the target client's data). More specifically, the target client may not be ready to receive data due to power saving or other reasons. For example, a target client such as STA N may enter PS mode after decoding the SIG, causing STA N to be unable to receive the data carried in the PPDU. AP device 110 can operate according to at least one control scheme (e.g., one or more control schemes) to perform a method of preemption management in a wireless communication system, preparing the target client to receive data and maintaining the power saving (PS) mechanism normally without hindering any implementation of PS mode, thereby improving overall performance.

[0027] Figure 3A target client control scheme is illustrated, which describes a method for performing preemption management in a wireless communication system according to an embodiment of the present invention. This method can be applied to wireless transceiver devices #m, such as AP device 110, and another wireless transceiver device #m', such as a non-AP STA device 120 (abbreviated as "AP" and "STA," respectively), in a plurality of wireless transceiver devices #1... and #M, to perform preemption management in a wireless communication system 100, and related operations of the wireless communication system 100 operating according to this method may include:

[0028] (1) The AP device 110 (or the communication control circuitry 114 therein) may execute a preemptive client indication 311 in at least one transmission action (e.g., one or more transmission actions), which may be collectively referred to as transmission action 310, at the beginning of transmission cycle 301 to indicate that the non-AP STA device 120 is a preemptive client and should remain awake during the preemptive cycle 302 within transmission cycle 301, wherein the preemptive cycle 302 may be reserved for transmitting latency-sensitive traffic to the non-AP STA device 120;

[0029] (2) The non-AP STA device 120 (or the communication control circuit 124 therein) may receive a preemptive client indication 311 in at least one of the above transmission actions, such as transmission action 310 at the beginning of transmission period 301, to indicate that the non-AP STA device 120 is the preemptive client and should remain awake in the preemptive period 302.

[0030] (3) In response to receiving the preemption client indication 311, the non-AP STA device 120 (or the communication control circuitry 124 therein) may remain awake during the preemption period 302 and be ready for any DL traffic or any UL trigger;

[0031] (4) The AP device 110 (or the communication control circuit 114 therein) can perform delay-sensitive traffic transmission during the preemption period 302;

[0032] The preemptive client indication may include a preemptive client ID, used to indicate that the non-access point workstation device 120 is a preemptive client. More specifically, it may further include one or more preemptive client resource element (RU) indicators, indicating at least one RU for delay-sensitive traffic transmission and channel bandwidth information for delay-sensitive traffic transmission. For example, the preemptive client ID may be implemented as either an associated ID (AID) or an ID different from the AID (e.g., a shorter ID (SID) than the AID). Furthermore, the preemptive client indication 311 may include a candidate preemptive client list for recording at least one candidate preemptive client (e.g., one or more candidate preemptive clients) suitable for delay-sensitive traffic transmission. This at least one candidate preemptive client may include the non-access point workstation device 120, but the invention is not limited thereto. Regardless of whether transmission action 310 represents a single transmission action (e.g., a single communication frame) or multiple transmission actions (e.g., multiple communication frames), AP device 110 may transmit a preemption client indication 311 carrying a list of candidate preemption clients at the beginning of transmission cycle 301, indicating that at least one of the candidate preemption clients includes non-access point workstation device 120, keeping at least one candidate preemption client awake during preemption cycle 302 and ready for any downlink traffic or any uplink trigger. For example, in the first case of a single transmission action and the second case of multiple transmission actions, a portion 313 of transmission action 310 may be arranged to carry downlink data transmitted to non-access point workstation device 120 during preemption cycle 302, while another portion 312 of transmission action 310 may be arranged to carry downlink data transmitted to another non-access point workstation device before preemption cycle 302.

[0033] Table 1

[0034] Preempt client ID RU ID(STA(N1)) RU(1) ID(STA(N2)) RU(2) … …

[0035] Table 1 shows an example of a candidate preemptive client list, which may include the preemptive client IDs of the candidate preemptive clients (e.g., workstations {STA(N)}), such as the preemptive client IDs {ID(STA(N1)), ID(STA(N2)), ...} of workstations {STA(N1)), STA(N2)), ...}, and preemptive client RU indicators {RU(1), RU(2), ...} indicating the resource units used to transmit delay-sensitive traffic to workstations {STA(N1)), STA(N2), ...}. The symbol “…” may indicate that some table content may be omitted, but the invention is not limited thereto. In some examples, the candidate preemptive client list, its format, table content, and / or the number of candidate preemptive clients may vary.

[0036] Table 2

[0037]

[0038] Table 2 shows another example of a candidate preemptive client list, which may include the preemptive client IDs of the candidate preemptive clients (e.g., workstations {STA(N)}), such as the preemptive client IDs {ID(STA(N1)), ID(STA(N2)), ...} of workstations {STA(N1)), STA(N2)), ...}, and preemptive client RU indicators RU(0) indicating the common resource unit used to transmit delay-sensitive traffic to any workstation STA(N) in workstations {STA(N1)), STA(N2), ...}. The symbol “…” may indicate that some table content may be omitted, but the invention is not limited thereto. In some examples, the candidate preemptive client list, its format, table content, and / or the number of candidate preemptive clients may vary.

[0039] Preemption management applies to at least one Physical Layer Protocol Data Unit (PPDU) level to reserve a preemption period 302 for delay-sensitive traffic transmission during PPDU transmission, but the invention is not limited thereto. For example, preemption management applies to at least one Transmission Opportunity (TXOP) level to reserve a preemption period 302 for delay-sensitive traffic transmission during TXOP. With respect to the TXOP level, the transmission period 302 may be a period corresponding to the TXOP, and the preemption client indication 311 may be carried in the initial control frame (ICF) of at least one of the aforementioned transmission actions (e.g., transmission action 310). In some examples, preemption management applies to any level, both the PPDU and TXOP levels. If any of the aforementioned levels represents a PPDU level, the transmission period 302 may be a period corresponding to the PPDU, and the preemption client indication 311 may be carried in at least one field of the at least one of the aforementioned transmission actions (e.g., transmission action 310) (e.g., at least one PPDU among a plurality of PPDUs, the plurality of PPDUs including PPDU 302 and any other PPDU 302). If any of the above levels represent the TXOP level, the transmission period 302 can be a period corresponding to the TXOP, and the preemptive client indication 311 can be carried in the ICF in at least one of the above transmission actions (e.g., transmission action 310).

[0040] According to certain embodiments, AP device 110 can operate according to the cross-link wake-up indication control scheme of the method to perform preemption by means of the cross-link wake-up indication. For example, AP device 110 and non-AP STA device 120 can be implemented as multi-link devices (MLDs), and thus can be referred to as AP MLD 110 and non-AP STA MLD 120, respectively, wherein AP MLD 110 can be configured to have multiple APs associated with AP MLD 110, which can cooperate closely to effectively utilize multiple wireless media and increase transmission / reception diversity. More specifically, the communication control circuit 114 may include multiple communication control circuits (e.g., two or more communication control circuits as two or more APs) to communicate with the non-AP STA MLD 120 respectively via multiple links (e.g., two or more links), which correspond to multiple predetermined radio frequency (RF) bands (e.g., two or more predetermined RF bands), such as the 2.4 GHz band, the 5 GHz band, and the 6 GHz band, and the communication control circuit 124 may include multiple communication control circuits (e.g., two or more communication control circuits as two or more STAs) to communicate with the AP MLD 110 respectively via multiple links (e.g., two or more links), which correspond to multiple predetermined RF bands (e.g., two or more predetermined RF bands), such as the 2.4 GHz band, the 5 GHz band, and the 6 GHz band. When a multi-link operation (MLO) device, such as AP MLD 110, is transmitting a long TX time PPDU to client 1 on link 1, and simultaneously some latency-sensitive traffic arrives at client 2, the MLO device, such as AP MLD 110, can send an indication to client 2 on another link, such as link 2, to wake up client 2 on link 1. For example, client 2 may be in PS mode because the PPDU is for client 1, but the PPDU may be preempted to transmit latency-sensitive traffic for client 2. This indication needs to be sent to client 2 in a timely manner to wake it up during the preemption of link 1 to receive any potential DL data.

[0041] Figure 4 A PPDU-level control scheme based on an embodiment of the present invention is illustrated. The transmission period 401 and the preemption period 402 can be respectively used as… Figure 3The example shown is a transmission cycle 301 and a preemption cycle 302, and PPDU 410 and preemption client indication 411 can be examples of the aforementioned transmission behavior 310 and preemption client indication 311, respectively. Transmission cycle 401 can be a cycle corresponding to PPDU 410, and preemption client indication 411 can be carried in at least one field within PPDU 410 (e.g., the field "Preamble and SIG"). Compared to PPDU 210A, which lacks the aforementioned preemption client indication, PPDU 410 includes preemption client indication 411 at the beginning of transmission cycle 401 to indicate that at least one candidate preemption client, such as a non-AP STA device 120, remains awake during preemption cycle 402 and is ready for any DL traffic or any UL trigger.

[0042] like Figure 4 As shown, the "Preamble and SIG" field can be arranged to carry a preemption client indication 411, such as the AID (or SID) of STA N. STA N may enter PS mode after decoding the SIG in the "Preamble and SIG" field, but will be woken up during the preemption period 402. For the sake of brevity, a similar description of this embodiment will not be repeated in detail here.

[0043] Figure 5 A PPDU-level control scheme according to another embodiment of the present invention is illustrated. Transmission period 501 and preemption period 502 can respectively serve as... Figure 3 The example shown is a transmission cycle 301 and a preemption cycle 302, and PPDU 510 and preemption client indication 511 can be examples of the aforementioned transmission behavior 310 and preemption client indication 311, respectively. Transmission cycle 501 can be a cycle corresponding to PPDU 510, and preemption client indication 511 can be carried in at least one field (e.g., the field "Preamble and SIG") within PPDU 510. Compared to PPDU 210B, which lacks the aforementioned preemption client indication, PPDU 510 includes preemption client indication 511 at the beginning of transmission cycle 501 to instruct at least one candidate preemption client, such as a non-AP STA device 120, to remain awake during preemption cycle 502 and prepare for any DL traffic or any UL trigger.

[0044] like Figure 5As shown, the "Preamble and SIG" field can be arranged to carry a preemption client indication 511, such as the AID (or SID) of STA N. STA N may enter PS mode after decoding the SIG in the "Preamble and SIG" field, but wake up before the Midamble (or before the "Midamble and SIG" field). If the preemption is not directed at STA N, STA N may enter PS mode after decoding the Midamble and SIG, until the PPDU 510 ends. For the sake of brevity, a similar description of this embodiment will not be repeated in detail here.

[0045] Figure 6 This describes a PPDU-level control scheme according to another embodiment of the present invention. Transmission period 601 and preemption period 602 can respectively serve as... Figure 3 The example shown is a transmission cycle 301 and a preemption cycle 302, while PPDU 610 and preemption client indication 611 can be examples of the aforementioned transmission behavior 310 and preemption client indication 311, respectively. Transmission cycle 601 may correspond to the cycle of PPDU 610, and preemption client indication 611 may be carried in at least one field (e.g., the field "Preamble and SIG") within PPDU 610. Compared to PPDU 210C, which lacks the aforementioned preemption client indication, PPDU 610 includes preemption client indication 611 at the beginning of transmission cycle 601 to instruct at least one candidate preemption client, such as non-AP STA device 120, to remain awake during preemption cycle 602 and prepare for any DL traffic or any UL trigger.

[0046] like Figure 6 As shown, the "Preamble and SIG" field can be configured to carry a preemption client indication 611, such as the AID (or SID) of STAN. STA N may enter PS mode after decoding the SIG in the "Preamble and SIG" field, but wake up before the Midamble (or the "Midamble and SIG" field). If the preemption is not directed at STA N, STA N may enter PS mode after decoding the Midamble and SIG until the end of PPDU 610. For the sake of brevity, a similar description of this embodiment will not be repeated in detail here.

[0047] Based on the PPDU-level control scheme, an additional indicator (e.g., preemptive client indication 311, such as any one of preemptive client indications 411, 511, and 611) is included in the "Preamble and SIG" field of the PPDU (e.g., any one of PPDUs 410, 511, and 611) to announce and / or predict at least one of the aforementioned candidate preemptive clients (e.g., one or more candidate preemptive clients), such as potential clients receiving DL data during preemption. These clients may be in PS mode until the preemption phase, but the invention is not limited thereto. One or more of these clients may not be allocated DL during preemption if necessary, for example, if client traffic may not arrive or resources may be insufficient to satisfy all potential clients. Furthermore, the indication can be separate from the client indication receiving DL data immediately after SIG in the "Preamble and SIG" field of the PPDU. If there is a "Midamble and SIG" field prior to preemption, the accurate resource allocation for preemption can be announced by the AP device 110 in the Midamble and SIG fields.

[0048] Regarding how AP device 110 determines and / or selects at least one of the aforementioned candidate preemptive clients (e.g., one or more candidate preemptive clients), certain implementation details, such as potential clients in Preamble and SIG, can be further described below. In addition to the target client control scheme, PPDU-level control scheme, etc., the aforementioned at least one control scheme of the method may also include a registration control scheme regarding the registration of non-AP STA device 120 (or client), and an announcement request control scheme regarding AP device 110 announcing and / or requesting to non-AP STA device 120 (or client).

[0049] According to the registration control scheme, before transmission cycle 301 (e.g., any one of transmission cycles 401, 501, and 601), AP device 110 can perform preemptive client registration for non-AP STA device 120 to add non-AP STA device 120 as a member of the candidate preemptive client list. For example, AP device 110 can perform preemptive client registration in response to a request from non-AP STA device 120. In another example, AP device 110 can perform preemptive client registration in response to a Stream Classification Service (SCS) procedure established between non-AP STA device 120 and AP device 110. More specifically, non-AP STA device 120, as a client, can send a frame to AP device 110 carrying a request to be included in the prediction in the preamble and SIG for potential DL preemption. This request can indicate which TID(s) are included in the preemption. AP device 110 can reject or accept the request by responding to the frame. A non-AP STA device 120 acting as a client can cancel the request by sending another frame requesting cancellation. Furthermore, when a non-AP STA device 120 acting as a client establishes an SCS procedure with AP device 110 (or AP MLD 110), this request can be implicitly set, for example, to include an Extremely High Throughput (EHT) SCS, a Mirrored Stream Classification Service (MSCS) procedure for a specific TID, UL, or DL, and any other SCS-based procedure. This implicit setting can be automatically canceled when the SCS procedure ends. Even if an SCS procedure has been established, the client can request not to be included in the potential DL preemption (or candidate preemption client list) by sending an additional request frame to AP device 110. Additionally, the preemption client ID, such as AID, may be 12 bits. To save on the length of the preempted client ID (i.e., the length of the preempted client ID), such as the AID length (i.e., the length of the AID), the AP device 110 can assign a shorter ID (SID) to the non-AP STA device 120, such as the SID mentioned above (e.g., a 6-bit SID), and use the SID for indication in the SIG.

[0050] According to the announcement-request control scheme, prior to transmission cycle 301 (e.g., any one of transmission cycles 401, 501, and 601), AP device 110 may decide to add non-AP STA device 120 as a member of the candidate preemption client list, as mentioned above, and notify non-AP STA device 120 of this decision via a first frame. For example, the first frame may be arranged to indicate one or more Traffic Identifiers (TIDs) included in preemption management. AP device 110 may send the first frame as a request (or announcement) to add non-AP STA device 120 to the candidate preemption client list, allowing non-AP STA device 120 to selectively accept AP device 110's decision, whereby non-AP STA device 120 can decide whether to accept (or reject) the request. When necessary, AP device 110 may selectively cancel AP device 110's decision and notify non-AP STA device 120 of the cancellation via a second frame. More specifically, AP device 110 may decide to include a client in a potential DL preemption (or candidate preemption client list) when any of the following conditions are met:

[0051] (1) The non-AP STA device 120 acting as a client has ongoing low-latency DL traffic, for example, ongoing low-latency DL traffic may include any traffic corresponding to either AC_VO (or voice access category) or AC_VI (or video access category) TID;

[0052] (2) Any negotiation of TID-to-link mapping for DL ​​transmission by the non-AP STA device 120 as a client; and

[0053] (3) There are any other reasons to improve the client’s DL service quality (QoS).

[0054] Furthermore, AP device 110 may use a first frame to notify and / or request a non-AP STA device 120 acting as a client, which has been included in a potential DL preemption (or candidate preemption client list). This request may indicate which TID(s) or all TIDs are included in the preemption. The non-AP STA device 120 acting as a client may accept or reject the request via a response frame; for example, the non-AP STA device 120 acting as a client may have higher priority to perform power saving. If the client no longer has latency-sensitive traffic, the request may subsequently be cancelled. For example, AP device 110 may send at least one additional frame (e.g., one or more additional frames) with optional TID information to the non-AP STA device 120 acting as a client to cancel the preemption of those TIDs or all TIDs. According to some embodiments, to save preemption client ID length, such as AID length, AP device 110 may assign a shorter ID (SID) to the non-AP STA device 120, such as the aforementioned SID (e.g., a 6-bit SID), and indicate this in the SIG, but the invention is not limited thereto.

[0055] Regardless of whether any of the aforementioned levels represent PPDU or TXOP levels, in the first case of a single transmission action and the second case of multiple transmission actions, AP device 110 may prepare a preemptive client indication 311 carrying a list of candidate preemptive clients to indicate to at least one of the aforementioned candidate preemptive clients, such as one or more candidate preemptive clients, including non-AP STA device 120, and transmit the preemptive client indication 311 to keep the candidate preemptive clients awake during the preemption period 302 and ready for any DL traffic or any UL trigger. More specifically, AP device 110 has and maintains a total list of preemptive clients regarding registration control schemes and / or announcement request control schemes, such as a list of clients that have registered (or been requested) for DL ​​preemption. AP device 110 may select a subset of the list to include in the candidate preemptive client list (e.g., the candidate preemptive client list is carried by the preamble and SIG of the PPDU, where any of the above levels represent the PPDU level) to create a preemptive client indication 311. The preemptive client indication 311 includes a subset or selected set of clients, including non-AP STA devices 120 (or STA N), so that these clients can be prepared for preemptive DL transmissions in preemptive cycle 302. Under the control of AP device 110, the preemptive client indication 311 can dynamically change between various transmission cycles 301 based on load and DL traffic conditions. For short transmission cycles within the various transmission cycles 301, AP device 110 may not need to include such an indication, the preemptive client indication 311, to save some overhead. Taking the PPDU level as an example, the preemptive client indication 311 can dynamically change between each PPDU based on load and DL traffic conditions. For short PPDUs, AP device 110 may not need to include such an indication to save some overhead, but the invention is not limited thereto. In some examples, if there are Midamble and SIG before preemption, the client that announces it will have DL data in Midamble and SIG can choose from either of the following:

[0056] (1) The preemptive client instruction in 311 in the Preamble and SIG of the PPDU; and

[0057] (2) All clients in the Preamble and SIG of the PPDU, including clients included in the Preamble Client Instruction 311 and clients not included in the Preamble and SIG of the PPDU.

[0058] In AP device 110, any of the aforementioned communication control circuits, such as communication control circuit 114, may include a PHY circuit and a MAC circuit, performing PHY and MAC layer operations respectively. AP device 110 can determine whether the DL data of any client in the preemptive client indication 311 in the Preamble and SIG of the PPDU arrives at the MAC circuit within the time interval between Preamble / SIG and Preamble / SIG (e.g., any time interval between the Preamble or SIG of the field "Preamble and SIG" and the Midamble or SIG of the field "Midamble and SIG") and is ready for transmission by the PHY circuit, in order to dynamically determine or select the clients announced in the Midamble and SIG. If the DL data of these clients arrives at the MAC circuit within the time interval and is ready for transmission by the PHY circuit, AP device 110 can select these clients to announce in the Midamble and SIG. AP device 110 can send additional notifications to these clients to decode the Midamble.

[0059] According to some embodiments, considering a list of candidate preemption clients, such as a list of STAs (e.g., STA N) for candidate preemption clients, another way to ensure that PPDU preemption (if data is allocated) can be correctly received is to regulate the behavior of these STAs after receiving the Preamble and SIG, even if these STAs are not indicated in the Preamble and SIG. For example, AP device 110 may be configured to force candidate preemption clients, such as these STAs, to always be prepared to receive preemption or data in the Midamble and SIG with full RX capability (e.g., multi-space stream (SS) reception), but the invention is not limited thereto. In a more efficient manner, AP device 110 and candidate preemption clients may be configured to operate with intra-PPDU spatial multiplexing power saving (SMPS), wherein candidate preemption clients, such as these STAs, maintain a spatial stream active, thus remaining able to receive the Midamble and SIG of the PPDU, and need to revert to the original RX spatial stream capability if preemption is to carry data to them. In some examples, candidate preemptive clients, such as these STAs, can be arranged to operate with any of the SMPS in the intra-PPDU SMPS (corresponding to the PPDU level) and intra-TXOP SMPS (corresponding to the TXOP level), depending on whether any of the aforementioned levels represents the PPDU level or the TXOP level, to keep a spatial stream active to receive subsequent instructions that arrive after the preemptive client instruction (e.g., subsequent instructions in Midamble and SIG).

[0060] As described above, at least one candidate preemption client (or "candidate preemption client") may include a non-AP STA device 120. When these candidate preemption clients, such as those STAs, operate with any of the aforementioned SMPS, including intra-PPDU SMPS and intra-TXOP SMPS, the non-AP STA device 120, which has been added as a candidate preemption client member, can also operate with any of the aforementioned SMPS, including intra-PPDU SMPS and intra-TXOP SMPS, to maintain a spatial stream active to receive subsequent instructions following the preemption client instruction. In response to a subsequent instruction indicating that AP device 110 is about to transmit to non-AP STA device 120, non-AP STA device 120 can restore its original RX spatial stream capability to activate multiple spatial streams to receive data (e.g., latency-sensitive data) from AP device 110. Furthermore, preemption management applies to any of the aforementioned levels, including the PPDU level and the TXOP level. If any of the above levels represent PPDU levels, the transmission period 302 may be a period corresponding to a PPDU, and the AP device 110 and the candidate preemptive client, such as the non-AP STA device 120, may be arranged to operate together with intra-PPDUSMPS, wherein the non-AP STA device 120 maintains a spatial stream active to receive subsequent indications that arrive after the preemptive client indication, such as subsequent indications within a PPDU, and in response to the subsequent indications, the non-AP STA device 120 activates multiple spatial streams to receive latency-sensitive data from the AP device 110, but the invention is not limited thereto. If any of the above levels represent the TXOP level, the transmission period 302 can be a period corresponding to the TXOP, and the AP device 110 and the candidate preemptive client, such as the non-AP STA device 120, can be arranged to operate together with intra-TXOP SMPS, wherein the non-AP STA device 120 maintains a spatial stream active to receive subsequent indications that arrive after the preemptive client indication, such as a subsequent indication within the TXOP, and in response to the subsequent indication, the non-AP STA device 120 activates multiple spatial streams to receive latency-sensitive data from the AP device 110.

[0061] According to some embodiments, regardless of whether any of the above levels represent PPDU or TXOP levels, it is recommended that clients be included in the DL preemption (or candidate preemption client list) only for a specific (service) period, such as during the Target Wake Time (TWT) service period (SP) or during the period specified by the client in the request frame, but the invention is not limited thereto. More specifically, for the latter of these two cases, the request frame carries Time Synchronization Function (TSF) information for the start and end times, and carries a beacon interval count to indicate when the period ends. For the sake of brevity, similar descriptions of these embodiments will not be repeated in detail here.

[0062] Figure 7 A TXOP-level control scheme based on an embodiment of the present invention is illustrated. Transmission period 701 and preemption period 702 can respectively serve as... Figure 3 The examples of transmission period 301 and preemption period 302 shown are illustrated, and frames from AP device 110 (labeled "AP" for brevity), such as ICF 711 and DL PPDUs 712 and 713 to STA STA1 and STA2 (labeled "DL PPDU to STA1" and "DL PPDU to STA2" for brevity), can serve as examples of at least one of the aforementioned transmission actions (or transmission action 310), wherein transmission period 702 may be a period corresponding to TXOP, and preemption client indication 311 may be carried in ICF 711. Upon receiving ICF 711 (e.g., Request to Send (RTS)), STA STA1 may reply with an ICF Response (ICR) (e.g., Clear Send (CTS)) and begin receiving DL PPDU 712, and send a Block Acknowledgment (BA) after completing the reception of DL PPDU 712.

[0063] Regarding the use of TXOP preemption in the TXOP level control scheme, the candidate preemption client list, such as the STA list for PPDU preemption, can also be used as the STA list for TXOP preemption, so that those STAs can be woken up during the TXOP preemption period 702. If a non-AP STA device 120, such as STA STA2, receives an ICF 711 from AP device 110 that is not directed to it, it can enter PS mode until the Network Allocation Vector (NAV) set by ICF 711 ends, before the preemption period 702 (for brevity, this is labeled "STA2 is not an ICF responder and may enter PS before the preemption period"), but the invention is not limited thereto. For example, a non-AP STA device 120, such as STA STA2, can continue to listen to the channel and wait for a channel using Enhanced Distributed Channel Access (EDCA). Furthermore, if AP device 110, as the TXOP holder, announces a potential preemption period during the TXOP period, such as preemption period 702, in advance or in some way before preemption period 702, candidate preemption clients, such as STAs in the candidate preemption client list, including non-AP STA devices 120 such as STA STA2, need to wake up during this preemption period 702 and prepare for any possible DL traffic or any UL trigger. For the sake of brevity, a similar description of this embodiment will not be repeated in detail here.

[0064] Figure 8The workflow of a method according to an embodiment of the present invention is illustrated. Wireless transceiver devices #m, such as AP device 110, and other wireless transceiver devices #m', such as non-AP STA devices 120, can, according to... Figure 8 The invention operates according to the workflow shown, but is not limited thereto.

[0065] In step S11, the AP device 110 (or communication control circuit 114) may execute a preemptive client indication 311 in at least one of the above-described transmission actions, such as transmission action 310 at the beginning of transmission cycle 301, to indicate that the non-AP STA device 120 is a preemptive client and should remain awake during the preemptive cycle 302 within transmission cycle 301, wherein the preemptive cycle 302 may reserve time for transmitting delay-sensitive traffic to the non-AP STA device 120. For example, when preemptive management is applied at the PPDU level, transmission cycle 301 and preemptive cycle 302 may respectively represent Figure 4 The transmission cycle 401 and preemption cycle 402 shown are as follows: Figure 5 The transmission cycle 501 and preemption cycle 502 shown are, or Figure 6 The transmission cycle 301 and preemption cycle 602 are shown in the diagram. In another example, when preemption management is applied at the TXOP level, the transmission cycle 301 and preemption cycle 302 can respectively represent... Figure 7 The transmission cycle 701 (e.g., corresponding to the TXOP cycle) and preemption cycle 702 are shown.

[0066] In step S12, the AP device 110 (or communication control circuit 114) may perform delay-sensitive traffic transmission during the preemption period 302. For example, since the preemption client indication 311 may include a candidate preemption client list for recording at least one candidate preemption client suitable for delay-sensitive traffic transmission, the non-AP STA device 120 may remain awake during the preemption period 302 and be ready to receive delay-sensitive traffic transmitted during the preemption period 302. For the sake of brevity, a similar description of this embodiment will not be repeated in detail here.

[0067] To better understand, you can... Figure 8 The workflow shown illustrates the method, but the invention is not limited thereto. According to some embodiments, it is possible to... Figure 8One or more steps can be added, deleted, or modified in the illustrated workflow. For example, a non-AP STA device 120 (or communication control circuitry 124) may receive a preemptive client indication 311 during at least one of the aforementioned transmission actions, such as transmission action 310 at the beginning of transmission cycle 301, to indicate that the non-AP STA device 120 is a preemptive client and should remain awake during preemption cycle 302. In response to receiving the preemptive client indication 311, the non-AP STA device 120 (or communication control circuitry 124) may remain awake during preemption cycle 302 and prepare for any DL traffic or any UL trigger. For the sake of brevity, similar descriptions of these embodiments will not be repeated in detail here.

[0068] Those skilled in the art will readily observe that many modifications and alterations can be made to the apparatus and methods while retaining the teachings of the present invention. Therefore, the above disclosure should be interpreted only within the scope and limits of the appended claims.

Claims

1. A method for performing preemption management in a wireless communication system, wherein a non-access point workstation device is wirelessly connected to a first access point (AP) device, the method comprising: The first AP device performs a preemptive client indication in at least one transmission action at the beginning of the transmission cycle to indicate that the non-access point workstation device is a preemptive client and should remain awake during the preemptive period within the transmission cycle; This preemption period is reserved for transmitting latency-sensitive traffic to the non-access point workstation device.

2. The method of claim 1, further comprising: The first AP device performs the latency-sensitive traffic transmission during the preemption period.

3. The method of claim 1, wherein the preemption management is applied to at least one Transmission Opportunity (TXOP) level to reserve the preemption period for the transmission of the delay-sensitive traffic during the TXOP.

4. The method of claim 3, wherein with respect to the TXOP level, the transmission period is the period corresponding to the TXOP, and the preemptive client indicates that it is carried in the initial control frame (ICF) of the at least one transmission action.

5. The method of claim 1, wherein the preemption management is applied to at least one physical layer (PHY) protocol data unit (PPDU) level to reserve the preemption period for the delay-sensitive traffic transmission during PPDU transmission.

6. The method of claim 1, wherein the preemptive client indication includes a candidate preemptive client list for recording at least one candidate preemptive client suitable for the latency-sensitive traffic transmission, wherein the at least one candidate preemptive client includes the non-AP STA device.

7. The method of claim 6, wherein prior to the transmission cycle, the first AP device is configured to perform preemptive client registration on the non-APSTA device in order to add the non-APSTA device as a member of the at least one candidate preemptive client to the candidate preemptive client list.

8. The method of claim 7, wherein the first AP device is configured to perform the preemptive client registration in response to a request from the non-AP STA device.

9. The method of claim 7, wherein the first AP device is configured to perform the preemptive client registration in response to a Flow Classification Service (SCS) procedure established between the non-AP STA device and the first AP device.

10. The method of claim 6, wherein prior to the transmission cycle, the first AP device is configured to decide to add the non-AP STA device as a member of the at least one candidate preemptive client to the candidate preemptive client list, and to notify the non-AP STA device of the decision via a first frame.

11. The method of claim 10, wherein the first frame is arranged to indicate one or more traffic identifiers (TIDs) included in the preemption management.

12. The method of claim 10, wherein the first AP device is configured to send the first frame as a request or announcement to add the non-AP STA device to the candidate preemption client list, thereby allowing the non-AP STA device to selectively accept the decision of the first AP device.

13. The method of claim 10, wherein the first AP device is configured to selectively cancel the decision and notify the non-AP STA device of the cancellation via a second frame.

14. The method of claim 1, wherein the preemptive client indication includes a preemptive client identifier (ID) indicating that the non-AP STA device is the preemptive client.

15. The method of claim 14, wherein the preemptive client ID is implemented as either an associated ID (AID) or an ID different from the AID.

16. The method of claim 14, wherein the preemptive client indication further comprises one or more preemptive client resource unit (RU) indicators indicating at least one RU for the delay-sensitive traffic transmission and channel bandwidth information for the delay-sensitive traffic transmission.

17. The method of claim 1, wherein the first AP device is configured to transmit the preemption client indication carrying a list of candidate preemption clients, indicating that at least one candidate preemption client includes the non-AP STA device, so that the at least one candidate preemption client remains awake during the preemption period and is ready for any downlink (DL) traffic or any uplink (UL) trigger.

18. The method of claim 17, wherein the at least one candidate preemptive client is arranged to operate with any Spatial Multiplexing Power Saving (SMPS), including intra-TXOP SMPS and intra-PPDU SMPS, to keep a spatial stream active to receive a subsequent indication following the preemptive client indication; and in response to the subsequent indication indicating that the first AP device is about to transmit to the non-AP STA device, the non-AP STA device is arranged to restore its original receive (RX) spatial stream capability to activate multiple spatial streams to receive data from the first AP device.

19. An access point (AP) device for performing preemption management in a wireless communication system, the AP device comprising: A processing circuit that arranges and controls the operation of the AP device; as well as At least one communication control circuit, coupled to the processing circuit, is arranged to perform communication control, wherein the at least one communication control circuit is arranged to perform wireless communication operation with at least one other device in the wireless communication system for use by the AP device, wherein a non-AP STA device among the at least one other device is wirelessly connected to the AP device; in: The AP device is scheduled to execute a preemptive client indication in at least one transmission action at the beginning of a transmission cycle, indicating that the non-AP STA device is a preemptive client and should remain conscious during the preemption period of that transmission cycle; and This preemption period is reserved for transmitting latency-sensitive traffic to the non-AP STA device.

20. A non-AP STA device for performing preemption management in a wireless communication system, the non-AP STA device comprising: A processing circuit that arranges and controls the operation of the non-AP STA device; as well as At least one communication control circuit, coupled to the processing circuit, is arranged to perform communication control, wherein the at least one communication control circuit is arranged to perform wireless communication operation with at least one other device in the wireless communication system for use by the non-APSTA device, wherein the non-APSTA device is wirelessly connected to a first access point (AP) device among the at least one other device; in: The non-AP STA device is scheduled to receive a preemptive client indication in at least one transmission action at the beginning of a transmission cycle, indicating that the non-AP STA device is a preemptive client and should remain conscious during the preemptive period within the transmission cycle, wherein the preemptive period is reserved for transmitting latency-sensitive traffic to the non-AP STA device. and In response to receiving the preemption client instruction, the non-AP STA device is scheduled to remain awake during the preemption period and be ready for any downlink (DL) traffic or any uplink (UL) trigger.

21. The non-AP STA device as claimed in claim 20, wherein the non-AP STA device is configured to operate with any Spatial Multiplexing Power Saving (SMPS), including intra-TXOP SMPS and intra-PPDU SMPS, to maintain a spatial stream active to receive a subsequent indication following the preemptive client indication; and in response to the subsequent indication indicating that the first AP device is about to transmit to the non-AP STA device, the non-AP STA device is configured to restore its original receive (RX) spatial stream capability to activate multiple spatial streams to receive data from the first AP device.

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