R-TWT Schedule Coordination Across Overlapping Wi-Fi BSSs

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Solution Overview

Problem

The Restricted Target Wake Time (R-TWT) schedule in Wireless Fidelity (Wi-Fi) networks is limited to a single basic service set and fails to coordinate between overlapping basic service sets (OBSS), leading to signal interference due to conflicting service times.

Innovation Solution

An R-TWT schedule adjustment method that coordinates R-TWT schedules between AP devices in overlapping basic service sets (OBSS) by adjusting service times and frequency domain resources to prevent interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If R-TWT schedules are independently established in each BSS, then low-latency service communication is ensured within the BSS, but signal interference occurs between BSSs in OBSS scenarios

Engineering Contradiction:
Improvelow-latency service communication reliabilityVSAvoidsignal interference between BSSs
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent merges the scheduling decisions of multiple BSSs by having APs exchange R-TWT schedule information and jointly determine non-overlapping service periods. This combines previously independent scheduling systems into a coordinated system that eliminates inter-BSS interference while maintaining low-latency service guarantees.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces schedule information exchange as an intermediary mechanism between APs in different BSSs. By sharing R-TWT schedule data through communication frames, APs can coordinate their service periods without direct interference, acting as mediators that resolve the contradiction between independent operation and interference avoidance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If R-TWT service periods are extended to cover more time, then more low-latency services can be accommodated, but the probability of conflict with other BSSs increases

Engineering Contradiction:
Improvenumber of low-latency services accommodatedVSAvoidconflict probability with other BSSs
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent resolves the time-dimension conflict by introducing coordination in the information-exchange dimension. APs share schedule information and coordinate service periods across BSS boundaries, effectively adding a coordination dimension that allows extended service periods without increased conflict probability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Object-affected harmful factors

If R-TWT schedules are coordinated between BSSs, then signal interference is reduced, but system complexity increases due to additional information exchange

Engineering Contradiction:
Improvesignal interference between BSSsVSAvoidschedule coordination system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts the coordination function from the core R-TWT mechanism by implementing it as a separate information-exchange process. APs exchange schedule information through dedicated frames and independently adjust their schedules based on received information, separating the coordination complexity from the fundamental R-TWT operation.

Inventive Principle:
Principle #2Taking out (Extraction)

4Object-affected harmful factors

If R-TWT service periods are made flexible to avoid conflicts, then interference with other BSSs is reduced, but the guarantee of low-latency service is weakened

Engineering Contradiction:
Improveinterference with other BSSsVSAvoidlow-latency service guarantee
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies preliminary action by having APs exchange schedule information before establishing R-TWT service periods. This advance coordination allows APs to pre-determine non-overlapping time windows, ensuring both low-latency service guarantees and interference avoidance from the outset rather than adjusting later.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4642126A1R-TWT protocol adjustment method and apparatus, and device and storage medium
Publication Date: 2025.10.29 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4642126A1 patent drawingFigure 1~2
  • EP4642126A1 patent drawingFigure 3~4
  • EP4642126A1 patent drawingFigure 5~6

AI summary

The embodiments of the present disclosure relate to the technical field of communications. Provided are a restricted target wake time (R-TWT) schedule adjustment method and apparatus, and a device and a storage medium, which can be applied to a first AP device. The method comprises : receiving at least one first frame, wherein each first frame comprises a first R-TWT schedule between one second AP device and at least one station (STA) device in a basic service set (BSS) of the second AP device, and a first AP device and each second AP device form an overlapping basic service set (OBSS); and adjusting at least one second R-TWT schedule according to each received first R-TWT schedule, wherein each second R-TWT schedule is an R-TWT schedule between the first AP device and one STA device in the BSS of the first AP device. In the embodiments of the present disclosure, in an OBSS scenario, an R-TWT schedule between at least one AP device and at least one STA device in a BSS of the AP device can be coordinated, so as to reduce interference between low-latency service communications between BSSs in the OBSS scenario.