Wi-Fi Duration Signaling for Unlicensed Spectrum Interference Avoidance

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Solution Overview

Problem

Inter-system interference occurs between communications systems using unlicensed spectrum due to channel occupation issues, particularly affecting sidelink-unlicensed (SL-U) systems when Wi-Fi systems occupy channels for extended periods, leading to reduced performance.

Innovation Solution

A first device broadcasts a Wi-Fi message with duration indication information to indicate other systems, such as Wi-Fi, to skip channel occupation for a specified duration, allowing communication to continue within the same system while reducing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple communications systems share the unlicensed spectrum, then spectrum utilization is improved, but inter-system interference increases

Engineering Contradiction:
Improvespectrum utilizationVSAvoidinter-system interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by having the first device send a Wi-Fi message before actually transmitting data on the unlicensed spectrum. This message reserves the channel in advance, indicating to other systems (particularly Wi-Fi) that the channel is occupied. By performing this reservation action before the main communication, the patent prevents inter-system interference while ensuring spectrum utilization, as other devices will avoid the reserved channel during the indicated time period.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a device continuously monitors channel occupancy, then interference detection is improved, but power consumption increases

Engineering Contradiction:
Improveinterference detectionVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies self-service by having the first device send a Wi-Fi message that includes information about its own upcoming transmission. This message serves dual purposes: it reserves the channel for the first device's own use, and simultaneously informs other devices to avoid the channel. The first device doesn't need to continuously monitor for interference because it has already proactively announced its occupancy intentions, allowing other devices to self-regulate their channel access based on this information.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4161193B1Inter-system interference avoidance method, device and system
Publication Date: 2026.04.22 HUAWEI TECH CO LTD
  • EP4161193B1 patent drawingFigure 1a~1b
  • EP4161193B1 patent drawingFigure 1c
  • EP4161193B1 patent drawingFigure 1d~1e

AI summary

Embodiments of this application provide an inter-system interference avoidance method, a device, and a system, and relate to the field of communications technologies, to reduce inter-system interference between various communications systems on an unlicensed spectrum. The method includes: A first device broadcasts a wireless fidelity Wi-Fi message. The first device performs communication by using a first communications system. The first communications system is a sidelink-unlicensed SL-U system, a new radio-unlicensed NR-U system, or a licensed assisted access LAA system. The Wi-Fi message includes duration indication information. The duration indication information is used to indicate first duration. The first duration is used to indicate a second device to skip occupying a first channel within the first duration. A spectrum on which the first channel is located is an unlicensed spectrum. The second device is a device that performs communication by using a Wi-Fi system. The first device sends first information to a third device by using the first communications system. The first information includes service data and/or control information.