Multi-Link NAV Sharing for Secondary WLAN Channel Access

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Solution Overview

Problem

Existing wireless LAN systems face challenges in accessing secondary channels when the primary channel is busy, leading to inefficiencies and potential failures due to mismatched Network Allocation Vector (NAV) settings between transmitting and receiving devices.

Innovation Solution

A method and apparatus for sharing NAV information between multi-link devices (MLDs) to enable efficient access to secondary channels by indicating RU allocation in an ascending order based on the lowest subcarrier frequency, ensuring synchronized NAV settings across devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the primary channel is busy, then the device cannot access the primary channel for transmission, but the secondary channel could be used to improve medium utilization efficiency

Engineering Contradiction:

Improvemedium use efficiencyVSAvoidsecondary channel access reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent divides the channel into primary and secondary channels, allowing independent access to each. When the primary channel is busy, the device can segment the transmission and use the secondary channel separately, improving medium utilization without affecting primary channel operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The NAV information sharing mechanism acts as an intermediary to coordinate access between primary and secondary channels. By sharing NAV settings, it ensures that secondary channel access does not cause conflicts with primary channel transmissions, resolving the reliability concern.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If NAV information is not shared between devices, then each device independently manages its NAV, but this causes mismatched NAV settings leading to failed secondary channel access

Engineering Contradiction:

Improveindependent NAV managementVSAvoidsecondary channel access success rate

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where NAV information is shared between transmitting and receiving devices. The receiving device sends back the NAV information it derived from the transmitted frame, allowing the transmitting device to verify and correct any mismatches, ensuring reliable secondary channel access.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent performs preliminary NAV information sharing before secondary channel access attempts. By establishing synchronized NAV settings in advance through information exchange, the system prevents mismatches that would otherwise cause access failures.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP4727249A1Method and apparatus for sharing NAV information for secondary channel access in wireless LAN system

Publication Date: 2026.04.15 LG ELECTRONICS INC

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AI summary

Disclosed are a method and an apparatus for sharing NAV information for secondary channel access in a wireless LAN system. A method performed by a first MLD, according to an embodiment of the present disclosure, may comprise the steps of: a first STA belonging to the first MLD receiving a first frame from a first AP belonging to a second MLD through a first link, the first link and a second link being configured for a multi-link operation, and the first frame including first NAV information regarding an NAV of a second AP belonging to the second MLD configured for a primary channel of the second link; and on the basis of the first NAV information, a second STA belonging to the first MLD receiving a second frame from the second AP on one or more secondary channels of the second link.