Trigger-Based Negotiation for Wireless Time-Synchronization Overhead

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Solution Overview

Problem

Time-sensitive wireless networks face inefficiencies in time-synchronization, particularly in large networks where existing protocols like IEEE 802.1AS require individual sessions for synchronization, leading to high signaling overhead and reduced efficiency.

Innovation Solution

Implementing a trigger-based (TB) negotiation mechanism that groups stations into polling and non-polling groups, allowing the responding STA to determine which ISTAs require polling or not, thereby bypassing unnecessary polling phases and directly triggering measurement phases for non-polling devices, optimizing the 802.11az FTM protocol for reduced overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If individual time-synchronization sessions are performed for each station according to IEEE 802.1AS, then time-synchronization accuracy is improved, but signaling overhead increases and efficiency decreases

Engineering Contradiction:
Improvetime-synchronization accuracyVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent merges multiple individual time-synchronization sessions into a single group-based synchronization process. Stations are divided into polling groups, and the AP performs collective time-synchronization measurements with each group rather than individually with every station. This combining approach maintains synchronization accuracy while significantly reducing the number of signaling exchanges required.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the network into multiple polling groups, where each group contains multiple stations. By organizing stations into these segments, the system can perform time-synchronization in a structured manner that reduces overall overhead. Each group is handled as a unit during the polling phase, preventing measurement conflicts and reducing the total number of synchronization sessions needed.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If polling phase is performed for all stations, then time-synchronization accuracy is improved, but time consumption and overhead increase

Engineering Contradiction:
Improvetime-synchronization accuracyVSAvoidtime consumption
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by performing polling only for specific groups of stations that require it, rather than for all stations universally. The AP determines which stations need polling based on their characteristics and requirements, and applies the polling phase selectively. This prevents unnecessary time consumption on stations that do not require polling while maintaining accuracy for those that do.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent introduces dynamic group management where polling groups are formed and updated based on network conditions and station requirements. The system can adaptively adjust which stations are placed in polling groups versus non-polling groups, optimizing the balance between measurement accuracy and time consumption. This dynamic approach allows the system to respond to changing network conditions and station needs.

Inventive Principle:
Principle #15Dynamics

3Reliability

If more polling groups are created, then measurement conflicts are reduced, but device complexity increases

Engineering Contradiction:
Improvemeasurement conflict reductionVSAvoidgroup management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent creates polling groups that serve multiple functions simultaneously: they reduce measurement conflicts by separating stations in time, they enable efficient resource allocation, and they provide a framework for both polling and non-polling operations. This multi-functionality means that the group structure itself handles multiple tasks, reducing the need for separate mechanisms and thereby limiting the increase in device complexity despite the benefits.

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

Data Source

PatentEP4475509A1Efficient time-synchronization in wireless time-sensitive networks using trigger-based negotiation for mixed polling and non-polling operation
Publication Date: 2024.12.11 INTEL CORP
  • EP4475509A1 patent drawingFigure 1~2
  • EP4475509A1 patent drawingFigure 3~4
  • EP4475509A1 patent drawingFigure 5

AI summary

A station (STA), when operating as a responding STA (RSTA) for time-synchronization of a plurality of initiating STAs (ISTAs) in a time-synchronized network (TSN), may determine, during a negotiation phase, whether each of the ISTAs that intend to participate in one or more measurement phases are requesting to be polled or are requesting not to be polled. For the ISTAs that are requesting to be polled, the RSTA may perform a polling phase prior to performing each of the one or more measurement phases. For the ISTAs that are requesting not to be polled, the RSTA may refrain from performing a polling phase prior to performing each of the one or more measurement phases. The RSTA can directly trigger the measurement phase for ISTAs that are requesting not to be polled. By grouping ISTAs into polling and non-polling groups, efficiency improvements are achieved.