US-12628200-B2 - Early frame check sequence (FCS) for trigger frame validation

Abstract

This disclosure provides methods, devices, and systems for wireless communications. The present implementations more specifically relate to trigger frame designs that support early validation of trigger frames. In some aspects, an AP may transmit a trigger frame soliciting a trigger-based (TB) physical layer convergence protocol (PLCP) protocol data unit (PPDU) from one or more wireless stations (STAs), where the trigger frame includes one or more user information fields, an early frame check sequence (eFCS) following the user information fields, a series of padding bits following the eFCS, and a frame check sequence (FCS) following the series of padding bits. Each STA associated with the AP may receive and validate a first portion of the trigger frame based on the eFCS. Any non-solicited STAs that receive the trigger frame may enter a low power mode in response to validating the first portion of the trigger frame, without receiving the padding bits.

Inventors

• Girish Anantrao Madpuwar
• Saishankar Nandagopalan

Assignees

• SYNAPTICS INCORPORATED

Dates

Publication Date

20260512

Application Date

20231120

Claims (20)

1. 1 . A method for wireless communication by a wireless communication device, comprising: receiving a first portion of a trigger frame soliciting a trigger-based (TB) physical layer convergence protocol (PLCP) protocol data unit (PPDU) from one or more wireless communication devices, the trigger frame including one or more user information fields, a first frame check sequence (FCS) following the one or more user information fields, a plurality of padding bits following the first FCS, and a second FCS following the plurality of padding bits; validating the first portion of the trigger frame based on the first FCS; and selectively entering a low power mode which prevents the wireless communication device from receiving a second portion of the trigger frame that includes the plurality of padding bits, based on the one or more user information fields, in response to validating the first portion of the trigger frame.
2. 2 . The method of claim 1 , wherein the wireless communication device is configured to operate in an enhanced multi-link single-radio (EMLSR) mode.
3. 3 . The method of claim 1 , wherein the selective entering of the low power mode comprises: determining whether any of the one or more user information fields includes an association identifier (AID) subfield having a value that matches an AID associated with the wireless communication device; and entering the low power mode responsive to determining that none of the user information fields includes an AID subfield having a value that matches the AID associated with the wireless communication device.
4. 4 . The method of claim 3 , wherein the wireless communication device is configured to remain in the low power mode for a duration of the TB PPDU.
5. 5 . The method of claim 1 , wherein the selective entering of the low power mode comprises: determining whether any of the one or more user information fields includes an AID subfield having a value that matches an AID associated with the wireless communication device; and refraining from entering the low power mode responsive to determining that one of the user information fields includes an AID subfield having a value that matches the AID associated with the wireless communication device.
6. 6 . The method of claim 5 , further comprising: validating the trigger frame based on the second FCS; and transmitting the TB PPDU in response to validating the trigger frame.
7. 7 . The method of claim 1 , wherein the first FCS is carried in a special user information field following the one or more user information fields.
8. 8 . The method of claim 7 , wherein the special user information field includes an AID subfield having a value different than any AIDs associated with the one or more wireless communication devices.
9. 9 . The method of claim 1 , wherein the first FCS and the plurality of padding bits are carried in a padding field following the one or more user information fields.
10. 10 . The method of claim 9 , wherein the padding field includes an AID subfield having a value equal to 4095.
11. 11 . A wireless communication device, comprising: a processing system; and a memory storing instructions that, when executed by the processing system, cause the wireless communication device to: receive a first portion of a trigger frame soliciting a trigger-based (TB) physical layer convergence protocol (PLCP) protocol data unit (PPDU) from one or more wireless communication devices, the trigger frame including one or more user information fields, a first frame check sequence (FCS) following the one or more user information fields, a plurality of padding bits following the first FCS, and a second FCS following the plurality of padding bits; validate the first portion of the trigger frame based on the first FCS; and selectively enter a low power mode which prevents the wireless communication device from receiving a second portion of the trigger frame that includes the plurality of padding bits, based on the one or more user information fields, in response to validating the first portion of the trigger frame.
12. 12 . The wireless communication device of claim 11 , wherein the wireless communication device is configured to operate in an enhanced multi-link single-radio (EMLSR) mode.
13. 13 . The wireless communication device of claim 11 , wherein the selective entering of the low power mode comprises: determining whether any of the one or more user information fields includes an association identifier (AID) subfield having a value that matches an AID associated with the wireless communication device; and entering the low power mode responsive to determining that none of the user information fields includes an AID subfield having a value that matches the AID associated with the wireless communication device.
14. 14 . The wireless communication device of claim 13 , wherein the wireless communication device is configured to remain in the low power mode for a duration of the TB PPDU.
15. 15 . The wireless communication device of claim 11 , wherein the selective entering of the low power mode comprises: determining whether any of the one or more user information fields includes an AID subfield having a value that matches an AID associated with the wireless communication device; and refraining from entering the low power mode responsive to determining that one of the user information fields includes an AID subfield having a value that matches the AID associated with the wireless communication device.
16. 16 . The wireless communication device of claim 15 , wherein execution of the instructions further causes the wireless communication device to: validate the trigger frame based on the second FCS; and transmit the TB PPDU in response to validating the trigger frame.
17. 17 . The wireless communication device of claim 11 , wherein the first FCS is carried in a special user information field following the one or more user information fields.
18. 18 . The wireless communication device of claim 17 , wherein the special user information field includes an AID subfield having a value different than any AIDs associated with the one or more wireless communication devices.
19. 19 . The wireless communication device of claim 11 , wherein the first FCS and the plurality of padding bits are carried in a padding field following the one or more user information fields.
20. 20 . The wireless communication device of claim 19 , wherein the padding field includes an AID subfield having a value equal to 4095.

Description

TECHNICAL FIELD The present implementations relate generally to wireless communication, and specifically to early frame check sequence (FCS) for trigger frame validation. BACKGROUND OF RELATED ART A wireless local area network (WLAN) may be formed by one or more access points (APs) that provide a shared wireless communication medium for use by a number of client devices, also referred to as wireless stations (STAs). The basic building block of a WLAN conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards is a Basic Service Set (BSS), which is managed by an AP. Each BSS is identified by a BSS Identifier (BSSID) that is advertised by the AP. An AP periodically broadcasts beacon frames to enable any STAs within wireless range of the AP to establish or maintain a communication link with the WLAN. The process of establishing a communication link is generally referred to as “association,” and involves an exchange of association frames between an AP and a STA. The STA is “associated” with the AP upon completion of the association process. Many STAs are battery-operated devices with limited power budgets. Some STAs may enter a low power mode (also referred to as a “power save” mode) to conserve power and extended battery life. However, while operating in the low power mode, a STA cannot transmit, receive, or listen to communications on a wireless channel. Thus, there is a need to increase the opportunities for a STA to enter or remain in a low power mode without hindering the STA's ability to communicate with a WLAN. SUMMARY This Summary is provided to introduce in a simplified form a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. One innovative aspect of the subject matter of this disclosure can be implemented in a method performed by a wireless communication device. The method includes receiving a trigger frame soliciting a trigger-based (TB) physical layer convergence protocol (PLCP) protocol data unit (PPDU) from one or more wireless communication devices, where the trigger frame includes one or more user information fields, a first frame check sequence (FCS) following the one or more user information fields, a plurality of padding bits following the first FCS, and a second FCS following the plurality of padding bits; validating a portion of the trigger frame based on the first FCS; and selectively entering a low power mode, based on the one or more user information fields, in response to validating the portion of the trigger frame and without receiving the plurality of padding bits. Another innovative aspect of the subject matter of this disclosure can be implemented in a wireless communication device including a processing system and a memory. The memory stores instructions that, when executed by the processing system, causes the wireless communication device to receive a trigger frame soliciting a TB PPDU from one or more wireless communication devices, where the trigger frame includes one or more user information fields, a first FCS following the one or more user information fields, a plurality of padding bits following the first FCS, and a second FCS following the plurality of padding bits; validate a portion of the trigger frame based on the first FCS; and selectively enter a low power mode, based on the one or more user information fields, in response to validating the portion of the trigger frame and without receiving the plurality of padding bits. BRIEF DESCRIPTION OF THE DRAWINGS The present implementations are illustrated by way of example and are not intended to be limited by the figures of the accompanying drawings. FIG. 1 shows an example wireless communication network. FIG. 2 shows a timing diagram depicting example wireless communications between an access point (AP) and a number of wireless stations (STAs) associated with the AP. FIG. 3 shows an example trigger frame usable for wireless communications between an AP and a number of STAs, according to some implementations. FIG. 4 shows another example trigger frame usable for wireless communications between an AP and a number of STAs, according to some implementations. FIG. 5 shows another example trigger frame usable for wireless communications between an AP and a number of STAs, according to some implementations. FIG. 6 shows another timing diagram depicting example wireless communications between an AP and a number of STAs associated with the AP, according to some implementations. FIG. 7 shows a block diagram of an example wireless communication device, according to some implementations. FIG. 8 shows an illustrative flowchart depicting an example trigger frame validation operation based on an early frame check sequence (FCS), according to some implementations. DETAILED DESCRIPTION In the