US-12627428-B2 - A-MPDU preemption for time-critical ultra-low latency (ULL) communications

US12627428B2US 12627428 B2US12627428 B2US 12627428B2US-12627428-B2

Abstract

Embodiments disclosed herein are directed to communicating time-critical ultra-low latency (ULL) data. An access point station (AP) communicates time-critical ULL data using aggregated MAC Protocol Data Unit (A-MPDU) preemption. When time-critical ULL data for a second associated STA (STA2) becomes available at a medium access control (MAC) layer of the AP during transmission of a physical layer protocol data unit (PPDU) to a first associate station (STA1), the AP may encode the time-critical ULL data in a new A-MPDU subframe for insertion before one of the A-MPDU subframes of the PPDU that has not yet been transmitted. The new A-MPDU subframe may be encoded to include zero-padding to set a size of the new A-MPDU subframe equal to a size of the A-MPDU subframe that has been preempted. The A-MPDU subframes 606 for STA1 may be encoded include a MAC address of the STA1 and the new A-MPDU subframe 608 may be encoded include a MAC address of the STA2.

Inventors

Juan Fang
Minyoung Park
Laurent Cariou
Qinghua Li
Dmitry Akhmetov
Xiaogang Chen
Dave A. Cavalcanti

Assignees

INTEL CORPORATION

Dates

Publication Date: 20260512
Application Date: 20220831

Claims (18)

1 . An apparatus of an access point station (AP), the apparatus comprising: processing circuitry; and memory, wherein the processing circuitry is configured to: encode a physical layer protocol data unit (PPDU) for transmission to a first associated station (STA1), the PPDU comprising a physical layer (PHY) preamble followed by a sequence of aggregated MAC Protocol Data Unit (A-MPDU subframe) subframes, initiate transmission of the PPDU; wherein when time-critical ultra-low latency (ULL) data for a second associated STA (STA2) becomes available at a medium access control (MAC) layer after transmission of the PPDU has been initiated, the processing circuitry is configured to: encode the time-critical ULL data in a new A-MPDU subframe, the new A-MPDU subframe encoded to include zero-padding to set a size of the new A-MPDU subframe equal to a size of a preempted one of the A-MPDU subframes when a size of the new A-MPDU subframe is less than a size of the preempted A-MPDU; and insert the new A-MPDU subframe before one of the A-MPDU subframes of the PPDU that has not yet been transmitted; and complete transmission of the PPDU without the preempted A-MPDU and with the new A-MPDU subframe included therein followed by remaining of the A-MPDU subframes for the STA1.
2 . The apparatus of claim 1 , wherein the processing circuitry is further configured to: encode the PHY preamble to include association identifier (AID) of the STA1; encode the A-MPDU subframes for the STA1 to include a MAC address of the STA1, and encode the new A-MPDU subframe for the STA2 to include a MAC address of the STA2.
3 . The apparatus of claim 2 , wherein the processing circuitry is further configured to: encode the A-MPDU subframes for the STA1 and indicate ACK; and encode the new A-MPDU subframe for the STA2 and indicate NACK.
4 . The apparatus of claim 3 , wherein the processing circuitry is further configured to encode the new A-MPDU subframe using one or more physical layer (PHY) parameters indicated in a signal field (SIG) of the PHY preamble of the PPDU.
5 . The apparatus of claim 4 , wherein the PPDU is encoded as a single user (SU) PPDU for the STA1, wherein prior to initiating transmission of the PPDU to the STA1, the AP and the STA2 have established a time-sensitive networking application that includes communication of the time-critical ULL data therebetween, and wherein as part of establishment of the time-sensitive networking application, the AP has indicated to the STA2 to decode PPDUs for STA1 for time-critical ULL data for STA2.
6 . The apparatus of claim 5 , wherein the time-critical ULL data for the STA2 is received at the MAC layer from an application upper layer of the AP, wherein the processing circuitry is configured to initiate transmission of the PPDU to the STA1 when there is no time-critical ULL data available for the STA2 in a transmission queue, and wherein when the time-critical ULL data for the STA2 is received at the MAC layer from the application upper layer of the AP after transmission of the PPDU has been initiated, the processing circuitry is configured to delay one of the A-MPDU subframes for the STA1 and insert the new A-MPDU subframe in the PPDU that includes that the time-critical ULL data for the STA2.
7 . The apparatus of claim 3 , wherein the time-critical ULL data has a latency requirement of less than or equal to one millisecond (ms).
8 . The apparatus of claim 7 , wherein the processing circuitry is configured to: insert the new A-MPDU subframe into the PPDU when transmission of the time-critical ULL data after transmission the PPDU would exceed the latency requirement; and refrain from inserting the new A-MPDU subframe when transmission of the time-critical ULL data after transmission the PPDU would not exceed the latency requirement.
9 . The apparatus of claim 8 , wherein after transmission of the PPDU is initiated and when the time-critical ULL data for the STA2 does not becomes available during transmission of the PPDU, the processing circuitry is configured to: refrain from encoding the time-critical ULL data in the new A-MPDU subframe; refrain from inserting the new A-MPDU subframe into the PPDU; and complete transmission of the PPDU with the A-MPDU subframes without the new A-MPDU subframe.
10 . A non-transitory computer-readable storage medium that stores instructions for execution by processing circuitry of an access point station (AP), the processing circuitry is configured to: encode a physical layer protocol data unit (PPDU) for transmission to a first associated station (STA1), the PPDU comprising a physical layer (PHY) preamble followed by a sequence of aggregated MAC Protocol Data Unit (A-MPDU subframe) subframes, initiate transmission of the PPDU; wherein when time-critical ultra-low latency (ULL) data for a second associated STA (STA2) becomes available at a medium access control (MAC) layer after transmission of the PPDU has been initiated, the processing circuitry is configured to: encode the time-critical ULL data in a new A-MPDU subframe, the new A-MPDU subframe encoded to include zero-padding to set a size of the new A-MPDU subframe equal to a size of a preempted one of the A-MPDU subframes when a size of the new A-MPDU subframe is less than a size of the preempted A-MPDU; and insert the new A-MPDU subframe before one of the A-MPDU subframes of the PPDU that has not yet been transmitted; and complete transmission of the PPDU without the preempted A-MPDU and with the new A-MPDU subframe included therein followed by remaining of the A-MPDU subframes for the STA1.
11 . The non-transitory computer-readable storage medium of claim 10 , wherein the processing circuitry is further configured to: encode the PHY preamble to include association identifier (AID) of the STA1; encode the A-MPDU subframes for the STA1 to include a MAC address of the STA1, and encode the new A-MPDU subframe for the STA2 to include a MAC address of the STA2.
12 . The non-transitory computer-readable storage medium of claim 11 , wherein the processing circuitry is further configured to: encode the A-MPDU subframes for the STA1 and indicate ACK; and encode the new A-MPDU subframe for the STA2 and indicate NACK.
13 . The non-transitory computer-readable storage medium of claim 12 , wherein the processing circuitry is further configured to encode the new A-MPDU subframe using one or more physical layer (PHY) parameters indicated in a signal field (SIG) of the PHY preamble of the PPDU.
14 . The non-transitory computer-readable storage medium of claim 13 , wherein the PPDU is encoded as a single user (SU) PPDU for the STA1, wherein prior to initiating transmission of the PPDU to the STA1, the AP and the STA2 have established a time-sensitive networking application that includes communication of the time-critical ULL data therebetween, and wherein as part of establishment of the time-sensitive networking application, the AP has indicated to the STA2 to decode PPDUs for STA1 for time-critical ULL data for STA2.
15 . The non-transitory computer-readable storage medium of claim 14 , wherein the time-critical ULL data for the STA2 is received at the MAC layer from an application upper layer of the AP, wherein the processing circuitry is configured to initiate transmission of the PPDU to the STA1 when there is no time-critical ULL data available for the STA2 in a transmission queue, and wherein when the time-critical ULL data for the STA2 is received at the MAC layer from the application upper layer of the AP after transmission of the PPDU has been initiated, the processing circuitry is configured to delay one of the A-MPDU subframes for the STA1 and insert the new A-MPDU subframe in the PPDU that includes that the time-critical ULL data for the STA2.
16 . An apparatus of a non-AP station (STA) (STA2), the apparatus comprising: processing circuitry; and memory, wherein for receiving time-critical ultra-low latency (ULL) data from an access point station (AP), the processing circuitry is configured to: decode a physical layer protocol data unit (PPDU) for a first associated station (STA1), the PPDU comprising a PHY preamble followed by a sequence of aggregated MAC Protocol Data Unit (A-MPDU subframe) subframes, decode the A-MPDU subframes to determine if one of the A-MPDU subframes have a MAC address of the STA2, wherein the time-critical ULL data is encoded in the one A-MPDU subframe that has the MAC address of the STA2.
17 . The apparatus of claim 16 , wherein when the one of the A-MPDU subframes have the MAC address of the STA2, the processing circuitry is configured to further decode the A-MPDU subframe and provide the time-critical ULL data to an application layer of the STA2.
18 . The apparatus of claim 17 , wherein the processing circuitry is further configured to: establish, with the AP, a time-sensitive networking application that includes communication of the time-critical ULL data therebetween, and wherein as part of the establishment of the time-sensitive networking application, the AP has indicated to the STA2 that PPDUs for STA1 may include A-MPDU subframes with a MAC address of the STA2 indicating the time-critical ULL data for STA2.

Description

TECHNICAL FIELD Embodiments pertain to wireless communications. Some embodiments relate to wireless networks including wireless local area networks (WLANS) including those operating in accordance with the IEEE 802.11 standards. Some embodiments relate to wireless time-sensitive networks (TSN) and wireless time-sensitive networking (WTSN). Some embodiments pertain to time-critical ultra-low latency (ULL) data communication. BACKGROUND One issue with communicating data over a wireless network is Emerging time-sensitive (TS) applications represent new markets for Wi-Fi. Industrial automation, robotics, AR/VR and HMIs (Human-Machine Interface) are example applications. Many time-sensitive applications require ultra-low latency (ULL) with minimal queuing and medium access delay within a wireless system. For instance, Programable Logic Controller (PLCs) may execute control loops requiring isochronous (cyclic) transmission of small time-critical (TC) packets (typically a few bytes) with cycles of 10's of microseconds. Furthermore, applications that need ULL typically also require very high reliability. The ULL requirement for TC packets practically imposes very high reliability requirements as multiple retransmissions (following the typical Wi-Fi protocols) are not feasible. Although IEEE 802.11ax has introduced triggered-based OFDMA operation, the overhead involved in the basic trigger-based data exchange within a TXOP is high, especially for small packet sizes. Many time-sensitive applications involve isochronous (cyclic) transmission of small packets (typically a few bytes) within very short cycles with high reliability. Thus what is needed are communication techniques suitable for time-sensitive applications that require lower overhead and are compatible with legacy network communications (i.e., IEEE 802.11ax and previous versions of the 802.11 standard). Thus, what is also needed is improved techniques to communicate time-critical ULL data. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A illustrates an example network, in accordance with some embodiments. FIG. 1B illustrates an enhanced wireless time sensitive networking (WTSN) medium access control/physical layer (MAC/PHY) configuration for a WTSN device, in accordance with some embodiments. FIG. 2 illustrates a timing diagram of an enhanced WTSN time synchronization, in accordance with some embodiments. FIG. 3A illustrates a control channel access sequence, in accordance with some embodiments. FIG. 3B illustrates a combined channel access sequence, in accordance with some embodiments. FIG. 3C illustrates an on-demand channel access sequence, in accordance with some embodiments. FIG. 4A illustrates an EHT MU PPDU format, in accordance with some embodiments. FIG. 4B illustrates an EHT TB PPDU format, in accordance with some embodiments. FIG. 5 illustrates channel access delay associated with simultaneous transmission and reception (STR) operations, in accordance with some embodiments. FIG. 6 illustrates aggregated MAC Protocol Data Unit (A-MPDU) preemption for time-critical ultra-low latency (ULL) communications, in accordance with some embodiments. FIG. 7 illustrates a functional block diagram of a wireless communication device, in accordance with some embodiments. FIG. 8 illustrates a procedure for communicating time-critical ULL data using A-MPDU preemption, in accordance with some embodiments. DETAILED DESCRIPTION The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims. Embodiments disclosed herein are directed to communicating time-critical ultra-low latency (ULL) data. In some embodiments, an access point station (AP) communicates time-critical ULL data using aggregated MAC Protocol Data Unit (A-MPDU) preemption. In these embodiments, when time-critical ULL data for a second associated STA (STA2) becomes available at a medium access control (MAC) layer of the AP during transmission of a physical layer protocol data unit (PPDU) to a first associate station (STA1), the AP may encode the time-critical ULL data in a new A-MPDU subframe for insertion before one of the A-MPDU subframes of the PPDU that has not yet been transmitted. In some of these embodiments, the new A-MPDU subframe may be encoded to include zero-padding to set a size of the new A-MPDU subframe equal to a size of the A-MPDU subframe that has been preempted. In some of these embodiments, the A-MPDU subframes 606 for STA1 may be encoded include a MAC address of the STA1 and the new A-MPDU subframe 608 may be encoded include a MAC address of the STA2. These embodiments, as well as others, are described in more detail herein. Rel