WLAN Unavailability Signaling for Multi-User Coexistence Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Managing coexistence events in wireless communication systems to reduce collisions and interference among multiple wireless technologies sharing radio resources is challenging, particularly in environments where devices operate using IEEE 802.11 standards and other technologies like Bluetooth.

Innovation Solution

Wireless devices transmit unavailability announcements to communication partners, indicating future periods of unavailability due to scheduled activities or coexistence events, allowing partners to adjust their transmissions and avoid resource conflicts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple wireless technologies share radio resources, then device versatility and connectivity are improved, but collisions and interference increase

Engineering Contradiction:

Improvedevice connectivityVSAvoidcollisions and interference

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by having devices announce their future unavailability periods in advance through control frames (such as MU-RTS or BSRP responses). This allows other devices to prepare for potential conflicts by adjusting their transmission schedules before collisions occur, thereby reducing interference while maintaining multi-technology sharing capability.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If devices continuously monitor and adjust transmissions to avoid collisions, then reliability is improved, but device complexity and overhead increase

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidcoexistence management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements feedback mechanisms where devices respond to control frames with unavailability information. This feedback loop allows the network to dynamically adjust transmissions based on real-time coexistence conditions, improving reliability without requiring complex continuous monitoring, as the feedback is triggered by specific control frame exchanges.

Inventive Principle:

Principle #23Feedback

3Object-affected harmful factors

If devices transmit frequent unavailability announcements, then collision avoidance is improved, but communication overhead increases

Engineering Contradiction:

Improvecollision avoidanceVSAvoidcommunication overhead

Core Design Contradiction:

Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The patent applies periodic action by integrating unavailability announcements into existing periodic control frame exchanges (such as MU-RTS/CTS or BSRP responses) rather than transmitting continuous or frequent separate announcements. This leverages the existing periodic communication infrastructure to convey coexistence information, reducing additional overhead while maintaining effective collision avoidance.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS20250351175A1Coexistence Unavailability Indication in a Multi-user Transmission Opportunity

Publication Date: 2025.11.13 APPLE INC

AI summary

Methods, systems and devices for transmitting unavailability information in a wireless local area network. A wireless device establishes first and second wireless connections using a first set of radio resources. The wireless devices receives a multi-user initial control frame (ICF) from a wireless access point over the first wireless connection. Based on receiving the multi-user ICF, the wireless device transmits a control response message to the wireless access point that indicates unavailability information for the wireless device.