Per-Sub-Band NAV Access for Dynamic Wi-Fi Channel Use

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Solution Overview

Problem

Current Wi-Fi 802.11 specifications underutilize spectrum due to virtual sensing network allocation vectors (NAV) being set on the entire bandwidth, preventing secondary channels from being used even if they are not busy, leading to inefficient spectrum usage, especially for bandwidth-limited stations with high data rate requirements.

Innovation Solution

Implementing per-bandwidth NAVs for stations to allow dynamic sub-band operation (DSO) and non-primary channel access (NPCA), enabling stations to transition to secondary channels based on actual channel usage, optimizing operations by correlating NAV with overlapping basic service set (OBSS) bandwidth and duration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If virtual sensing NAV is set on the entire bandwidth, then channel access control is simplified, but spectrum usage efficiency deteriorates

Engineering Contradiction:
Improvechannel access control complexityVSAvoidspectrum usage efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent divides the bandwidth into multiple sub-bands and implements separate NAV counters for each sub-band instead of a single NAV for the entire bandwidth. This segmentation allows independent channel access control for each sub-band, enabling stations to access available sub-bands while respecting reservations in other sub-bands, thus improving spectrum usage efficiency without significantly increasing control complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension to channel access control by implementing per-sub-band NAV counters and sub-band identification mechanisms. This dimensional expansion from a single bandwidth-level NAV to multiple sub-band-level NAVs enables fine-grained spectrum management, allowing stations to make informed access decisions based on the specific availability of each sub-band

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

2Device complexity

If bandwidth-limited stations operate only on primary channels, then device complexity is reduced, but data transmission efficiency deteriorates

Engineering Contradiction:
Improvestation operation complexityVSAvoiddata transmission efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent enables dynamic sub-band operation where bandwidth-limited stations can dynamically switch between primary and secondary sub-bands based on channel availability and their own bandwidth capabilities. This dynamic behavior allows stations to adapt to changing spectrum conditions and access available resources, significantly improving data transmission efficiency while maintaining manageable device complexity through standardized procedures

Inventive Principle:
Principle #15Dynamics

3Reliability

If stations reserve entire bandwidth using NAV, then channel access reliability is improved, but spectrum underutilization increases

Engineering Contradiction:
Improvechannel access reliabilityVSAvoidspectrum underutilization
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies local quality by implementing NAV reservations at the sub-band level rather than uniformly across the entire bandwidth. This allows different NAV values and reservation states for different sub-bands, enabling reliable channel access control where needed while leaving other sub-bands available for access, thus eliminating spectrum underutilization caused by conservative full-bandwidth reservations

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4648507A1Enhanced non-primary channel access, dynamic sub-band operation, and non-dynamic sub-band operation with per- bandwidth virtual sensing
Publication Date: 2025.11.12 INTEL CORP
  • EP4648507A1 patent drawingFigure 1
  • EP4648507A1 patent drawingFigure 2
  • EP4648507A1 patent drawingFigure 3

AI summary

This disclosure describes systems, methods, and devices for using a per-bandwidth virtual sensing network allocation vector (NAV) for sub-band operations. An access point may send an overlapping basic service set (OBSS) frame using at least a subset of an operating bandwidth of the access point, wherein the OBSS frame signals to a receiving device operating in the at least the subset of the operating bandwidth to set a network allocation vector (NAV) of the receiving device to on only in the at least the subset of the operating bandwidth; send an initial control frame (ICF) using the operating bandwidth; identify an initial control response (ICR) received, based on the ICF and based on the OBSS frame having used the at least the subset of the operating bandwidth; send an in-basic service set (in-BSS) transmission; and identify an acknowledgement to the in-BSS transmission.