TWT Scheduling Device Responder Passive Mode Operation

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Solution Overview

Problem

In augmented and virtual reality systems, network devices like access points and station devices face challenges with power management, leading to increased latency and congestion due to unpredictable availability during interstitial periods, which affects the seamless display of virtual objects and overall network performance.

Innovation Solution

Implementing a Target Wake Time (TWT) scheduling mechanism that includes a broadcast TWT element with a responder passive mode sub-field, allowing devices to switch to a sleep state outside of service periods and manage channel switching, thereby reducing power consumption and latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If devices switch to sleep state to reduce power consumption, then energy efficiency is improved, but device availability decreases causing increased latency

Engineering Contradiction:

Improvepower consumptionVSAvoidlatency

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The system performs preliminary actions by establishing TWT schedules in advance that define specific wake times and service periods. Devices know beforehand when they will be awake and available, eliminating the need for continuous monitoring or reactive wake-up procedures. This pre-planned approach allows devices to sleep soundly between scheduled times while ensuring immediate availability at designated wake times, thus reducing both power consumption and latency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements periodic action through structured TWT service periods that occur at regular, predictable intervals. Devices alternate between sleep states and active service periods in a periodic cycle. During service periods, devices are guaranteed to be awake and available for communication. This periodic pattern ensures that while devices consume minimal power during sleep intervals, they maintain predictable availability during their active periods, resolving the contradiction between energy saving and latency.

Inventive Principle:

Principle #19Periodic action

2Speed

If access points remain continuously available to serve stations, then network responsiveness is improved, but power consumption increases

Engineering Contradiction:

Improvenetwork responsivenessVSAvoidpower consumption

Core Design Contradiction:

SpeedVSUse of energy by stationary object

Solution Approach 1:

The access point dynamically adjusts its operational state based on scheduled TWT service periods rather than maintaining a static continuous availability mode. The AP transitions between active and sleep states according to the predefined TWT schedule, being fully responsive during service periods and power-saving during interstitial periods. This dynamic approach maintains network responsiveness when needed while significantly reducing overall power consumption.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the availability parameter of the access point from a constant true state (always available) to a time-varying state defined by TWT service periods. The availability parameter becomes a function of time, alternating between available and unavailable states according to the schedule. This parameter change allows the AP to maintain full responsiveness during service periods while reducing power consumption during unavailable periods, as the unavailability is predictable and scheduled rather than random or continuous.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If devices operate without structured scheduling, then operational flexibility is maintained, but network congestion increases

Engineering Contradiction:

Improveoperational flexibilityVSAvoidnetwork throughput

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments the network operations into distinct, non-overlapping TWT service periods for different devices or device groups. Each service period is allocated to specific stations, creating a segmented schedule that prevents simultaneous transmissions and reduces congestion. This segmentation maintains operational flexibility because schedules can be customized per station or group while improving overall network throughput by eliminating collisions and interference that occur in unscheduled operations.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS20250021150A1Systems and methods for responder passive mode operation

Publication Date: 2025.01.16 META PLATFORMS TECHNOLOGIES LLC

AI summary

Systems, methods, and devices for responder passive mode operation may include a target wake time (TWT) scheduling device which generates a broadcast TWT element, the broadcast TWT element including a control field including a responder passive mode (PM) mode sub-field. The TWT scheduling device may transmit the broadcast TWT element to one or more TWT scheduled devices within a basic service set (BSS) of the TWT scheduling device.