Multi-Link LL TWT Scheduling for NSTR Low-Latency Transmission

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Solution Overview

Problem

Existing wireless communication technologies struggle to guarantee low-latency service transmission requirements in scenarios involving multiple links, particularly due to out-of-band interference and unsynchronized data transmission, which can lead to incomplete data transfer during overlapping service periods.

Innovation Solution

A multi-link Low Latency Target Wake Time (LL TWT) mechanism is introduced for Non-Simultaneous Transmit and Receive (NSTR) Multi-Link Devices (MLDs), incorporating a leader/follower transmission mode to synchronize data transmission across multiple links, ensuring that low-latency services are completed within designated periods by aligning PPDU ending times and using a Quiet element to manage channel access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple links of NSTR MLD carry low-latency services simultaneously, then service throughput is improved, but out-of-band interference occurs and delay requirements cannot be guaranteed

Engineering Contradiction:
Improveservice throughputVSAvoiddelay requirement guarantee
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the service period into multiple sub-intervals, with each sub-interval dedicated to a specific link's low-latency service transmission. This segmentation prevents overlapping transmissions on different links, eliminating out-of-band interference while maintaining high throughput by systematically utilizing all links.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic link selection and service period allocation based on real-time channel conditions and service requirements. The system dynamically adjusts which link transmits during each sub-interval, optimizing throughput while ensuring delay requirements are met through adaptive resource management.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If data transmission is unsynchronized across multiple links, then device complexity is reduced, but data transfer completeness deteriorates during overlapping service periods

Engineering Contradiction:
Improvesynchronization complexityVSAvoiddata transfer completeness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements periodic service periods with fixed durations and predetermined sub-interval allocations for each link. This periodic structure ensures that transmissions on different links are time-multiplexed rather than synchronized, reducing the complexity of inter-link coordination while guaranteeing complete data transfer by preventing overlaps.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent pre-allocates specific sub-intervals to specific links before transmission begins, based on predetermined rules or agreements. This preliminary assignment eliminates the need for real-time synchronization decisions during transmission, reducing device complexity while ensuring data completeness through advance planning.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4322654B1Wireless communication method and device
Publication Date: 2026.03.25 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP4322654B1 patent drawingFigure 1~3
  • EP4322654B1 patent drawingFigure 4~5
  • EP4322654B1 patent drawingFigure 6

AI summary

The embodiments of the present disclosure provide a wireless communication method and device. When there is an overlapping region between LL TWT SPs on a plurality of links of an NSTR Non-AP MLD, leader/follower transmission modes on the multiple links are set, so as to solve the problem that a low-latency service on a certain link cannot be transmitted in an LL TWT SP as the NSTR Non-AP MLD cannot receive and transmit at the same time. Therefore, the transmission delay requirement of the low-latency service on the plurality of links of NSTR Non-AP MLD can be guaranteed, and the transmission on the plurality of links of the NSTR Non-AP MLD can be optimized.