Coordinated WLAN Stations: Frequency-Domain TXOP Sharing for Lower Latency

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Solution Overview

Problem

Current Wi-Fi network protocols do not effectively minimize latency for real-time applications, leading to increased delays in packet transmission due to reliance on AP-initiated UL transmissions and inefficient channel resource distribution.

Innovation Solution

A shared TXOP protocol is introduced, allowing non-AP STAs to initiate MU UL transmissions and schedule channel resources for other STAs within a single BSS, reducing the need for AP coordination and enabling immediate channel access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If non-AP STAs wait for AP-initiated UL transmissions, then channel access is coordinated and controlled, but latency increases for real-time applications

Engineering Contradiction:

ImprovelatencyVSAvoidchannel access coordination

Core Design Contradiction:

Loss of timeVSEase of operation

Solution Approach 1:

Non-AP STAs are empowered to autonomously initiate UL transmissions and share TXOPs without waiting for AP triggers. The STA that gains channel access can directly schedule other STAs using trigger frames, enabling self-service channel access that eliminates waiting delays while maintaining coordinated multi-user transmission through distributed scheduling.

Inventive Principle:

Principle #25Self-service

2Productivity

If AP coordinates all UL transmissions, then channel resource distribution is centralized and controlled, but channel utilization efficiency decreases

Engineering Contradiction:

Improvechannel utilization efficiencyVSAvoidcoordination overhead

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The centralized AP coordination function is segmented and distributed to individual non-AP STAs. Each STA that gains channel access becomes a temporary coordinator, capable of initiating UL transmissions and scheduling other STAs independently. This segmentation enables parallel channel access opportunities and improves overall channel utilization by eliminating the single-point coordination bottleneck.

Inventive Principle:

Principle #1Segmentation

3Loss of time

If non-AP STAs share TXOP in frequency domain, then latency is reduced for real-time applications, but resource allocation complexity increases

Engineering Contradiction:

Improvepacket transmission delayVSAvoidresource allocation management

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The patent transitions from time-domain TXOP sharing to frequency-domain resource unit (RU) allocation. The initiating STA allocates specific RUs within the shared TXOP to different STAs, enabling simultaneous frequency-division multi-user transmissions. This dimensional shift from temporal to spectral resource allocation reduces latency by allowing parallel transmissions while managing complexity through standardized RU assignment mechanisms.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4147528B1Coordinated stations in a single BSS with shared TXOP in the frequency domain

Publication Date: 2025.07.30 SONY GROUP CORP

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AI summary

A wireless local area network (WLAN) protocol allowing a Transmit Opportunity (TXOP) holder to share the TXOP with other stations acting cooperatively. An intent to share the TXOP is communicated to other stations that a TXOP is available for sharing, and notifying the Access Point (AP) station of the stations willing to join that TXOP. When the TXOP occurs, the stations can access the channel over different frequency domain simultaneously and for the duration specified, thus providing increased use of the TXOP to improve efficiency.