Shared TXOP Coordination Across OBSS to Cut WLAN Latency

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Solution Overview

Problem

Current WLAN protocols are limited in performance due to channel contention and interference between Basic Service Sets (BSS) and Overlapping Basic Service Sets (OBSS), leading to inefficiencies in TXOP transmission sharing and increased latency, especially in applications requiring real-time communication.

Innovation Solution

A wireless communications protocol that allows non-AP STAs to autonomously share a Transmit Opportunity (TXOP) with other STAs within the same BSS or OBSS, either through semi-static or dynamic methods, enabling direct communication and reducing reliance on AP scheduling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If non-AP STAs wait for AP trigger frames to initiate uplink transmission, then channel access is coordinated within BSS, but transmission latency increases and real-time communication performance deteriorates

Engineering Contradiction:
Improvetransmission latencyVSAvoidchannel access coordination
Core Design Contradiction:
Loss of timeVSEase of operation

Solution Approach 1:

Non-AP STAs autonomously initiate uplink transmissions by sensing channel availability and transmitting data without waiting for AP trigger frames. The STAs self-manage channel access coordination within their BSS, eliminating the mandatory waiting period for AP scheduling while maintaining orderly channel usage through carrier sense multiple access collision avoidance protocols.

Inventive Principle:
Principle #25Self-service

2Area of stationary object

If BSS and OBSS operate simultaneously in close proximity, then network coverage is extended, but channel contention and interference increase leading to packet losses

Engineering Contradiction:
Improvenetwork coverage areaVSAvoidpacket delivery reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent introduces a new dimension of operation by allowing non-AP STAs to autonomously access channels and share TXOPs across BSS and OBSS boundaries. This dimensional shift from AP-centric coordination to distributed STA autonomy enables simultaneous operation of overlapping networks while reducing contention through coordinated TXOP sharing among multiple STAs, thereby maintaining packet delivery reliability despite extended coverage area.

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

3Device complexity

If AP intermediates all TXOP sharing decisions, then centralized control is maintained, but device complexity and scheduling overhead increase

Engineering Contradiction:
Improvescheduling overheadVSAvoidcentralized control capability
Core Design Contradiction:
Device complexityVSExtent of automation

Solution Approach 1:

The patent extracts the TXOP sharing decision-making function from the AP and relocates it to non-AP STAs. Each STA independently determines whether to share its acquired TXOP with other STAs in the same or overlapping BSSs, eliminating the need for AP-mediated scheduling. This extraction significantly reduces AP device complexity and scheduling overhead while maintaining coordinated control through distributed autonomous decisions.

Inventive Principle:
Principle #2Taking out (Extraction)

4Productivity

If non-AP STAs autonomously share TXOP with STAs in OBSS, then channel utilization efficiency increases, but interference management complexity increases

Engineering Contradiction:
Improvechannel utilization efficiencyVSAvoidinterference management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent creates a universal TXOP sharing mechanism that operates across both intra-BSS and inter-BSS (OBSS) boundaries using the same autonomous decision-making framework. STAs apply identical procedures for determining TXOP sharing opportunities regardless of whether potential sharing partners are in the same BSS or overlapping BSSs. This universal approach maximizes channel utilization efficiency while avoiding the need for separate interference management protocols, thereby controlling complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4233441B1Coordinated stations in OBSS with shared TXOP in time domain
Publication Date: 2026.04.15 SONY GROUP CORP
  • EP4233441B1 patent drawingFigure 1~2
  • EP4233441B1 patent drawingFigure 3~5
  • EP4233441B1 patent drawingFigure 6

AI summary

A wireless local area network (WLAN) protocol allowing a Transmit Opportunity (TXOP) holder to share the TXOP with other stations (STAs) residing in either the same Basic Service Set (BSS) of the TXOP holder, or in an other BSS (OBSS). An intent to share the TXOP is communicated to the Access Point (AP), and/or directly to other STAs. Scheduling information (time and duration) are shared with the STAs either directly, or through one or more APs. When the TXOP occurs, the STAs can access the channel at the time and for the duration specified, thus providing increased use of the TXOP to improve efficiency.