Wi-Fi TWT Parameter Synchronization via Extended Frames

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Solution Overview

Problem

In Wi-Fi networks, when an access point (AP) attempts to update target wake time (TWT) parameters for multiple stations (STAs), some STAs may not receive the new parameters due to channel occupation or interference, leading to asynchronous wake-up times and inefficiencies in serving all STAs simultaneously with Orthogonal Frequency-Division Multiple Access (OFDMA).

Innovation Solution

The method involves transmitting an extended TWT response frame carrying new parameters and synchronization information during a first TWT service period, with stations that receive it implementing the changes at a predetermined time, and those that do not receive it getting a subsequent frame during a second TWT service period to synchronize with the others, ensuring all STAs wake up synchronously.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the AP transmits a TWT response frame to multiple STAs during a TWT service period, then the power consumption performance of STAs is improved, but some STAs may not receive the new parameters due to channel occupation or interference, leading to asynchronous wake-up times

Engineering Contradiction:

Improvepower consumption performanceVSAvoidparameter reception reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by having the AP transmit a first TWT response frame in advance during a first TWT service period, containing new TWT parameters and a first target wake time. This allows STAs to prepare for synchronized parameter updates before actually applying them, ensuring that all STAs receive and process the same parameters at the same time, thus preventing the reliability issue while maintaining power efficiency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the parameter update process into two distinct phases: (1) transmission phase where the AP sends the first TWT response frame during the first TWT service period, and (2) application phase where all STAs simultaneously apply the new parameters at the specified first target wake time. This segmentation ensures that STAs don't need to immediately process and apply parameters, allowing reliable reception while maintaining synchronized updates.

Inventive Principle:

Principle #1Segmentation

2Productivity

If the AP transmits new TWT parameters to multiple STAs, then the TWT parameters can be updated for power saving, but the beginnings of TWT service periods will be different for different STAs, preventing simultaneous OFDMA service

Engineering Contradiction:

Improveservice efficiencyVSAvoidsynchronization of TWT service periods

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent uses preliminary action by including a first target wake time in the first TWT response frame that specifies when all STAs should apply the new parameters. This predetermined time allows the AP to coordinate all STAs to transition to new parameters simultaneously, ensuring stable synchronization and enabling subsequent OFDMA operations without disrupting service efficiency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by having the AP transmit a second TWT response frame to STAs that have successfully applied the new parameters, confirming their status. This feedback mechanism ensures that all STAs are properly synchronized before the AP initiates OFDMA service, maintaining both stability and productivity.

Inventive Principle:

Principle #23Feedback

3Stability of the object's composition

If the AP waits for all STAs to receive new TWT parameters before updating, then synchronization is maintained, but the TWT service period duration is extended, reducing productivity

Engineering Contradiction:

Improvesynchronization of TWT parametersVSAvoidservice update speed

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent applies preliminary action by transmitting the new TWT parameters and target wake time in advance during the first TWT service period. STAs process and prepare to apply these parameters at the scheduled first target wake time without extending the current service period. This allows synchronization to be maintained while avoiding delays to productivity, as the parameter update occurs at a predetermined future time rather than requiring immediate coordination.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20240357490A1Method for setting target wake time

Publication Date: 2024.10.24 REALTEK SEMICON CORP

AI summary

A method for setting a target wake time (TWT) includes the following steps: making an access point transmit an extended TWT response frame to N stations during a first TWT service period (SP), wherein the frame carries new TWT parameters and TWT synchronization information; when M station(s) of the N stations receive(s) the extended TWT response frame and (N−M) station(s) of the N stations do(es) not receive the extended TWT response frame, making the M station(s) use the new TWT parameters at a predetermined time point according to the TWT synchronization information and then making the accessing point transmit a next extended TWT response frame to the (N−M) station(s) during a second TWT SP to request the (N−M) station(s) to apply the new TWT parameters at the predetermined time point, wherein the predetermined time point is not earlier than the end of the second TWT SP.