Deterministic Stream Scheduling for Jitter-Tolerant TSN Bridging

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Solution Overview

Problem

In networks like 5th Generation System (5GS) used as a bridge for Time-Sensitive Networking (TSN), jitter on transmission links between nodes affects deterministic flow transmission, and existing solutions require strict clock synchronization, which is costly and impractical.

Innovation Solution

A method and system that determine specified queue information for service packets based on a scheduling and forwarding mapping correspondence between transmission nodes, allowing packets to enter specific cyclic scheduling queues, ensuring deterministic forwarding even with asynchronous clocks and jitter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If strict clock synchronization is implemented between transmission nodes, then deterministic flow transmission can be achieved, but system complexity and cost increase significantly

Engineering Contradiction:
Improvedeterministic flow transmissionVSAvoidclock synchronization system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a scheduler as an intermediary component that mediates between transmission nodes with asynchronous clocks. The scheduler receives packets from the transmission node and determines appropriate transmission times based on pre-established scheduling information, eliminating the need for direct clock synchronization between nodes while maintaining deterministic transmission guarantees.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements preliminary scheduling actions where transmission timing information is pre-calculated and stored before actual packet transmission. The scheduler uses this pre-established scheduling information to determine when packets should be transmitted, allowing deterministic flow transmission to be achieved without requiring real-time clock synchronization between nodes.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If packet processing and retransmission mechanisms are introduced in 5GS, then reliability is improved, but jitter increases on transmission links

Engineering Contradiction:
Improvepacket transmission reliabilityVSAvoidtransmission timing stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent extracts the timing control function from the packet processing mechanism. Instead of relying on synchronized clocks at each node to maintain timing stability, the scheduling information is extracted and stored in a centralized scheduler, which then manages transmission timing independently of the packet processing and retransmission operations in the 5GS network.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The scheduler acts as an intermediary that decouples the packet processing functions (which may introduce jitter) from the transmission timing control. By using the scheduler to manage when packets are actually transmitted based on pre-established schedules, the system maintains timing stability even though packet processing and retransmission mechanisms are present in the network.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If jitter compensation mechanisms are implemented, then deterministic transmission can be maintained, but additional processing complexity is required

Engineering Contradiction:
Improvedeterministic transmission guaranteeVSAvoidjitter compensation system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of implementing complex real-time jitter compensation mechanisms, the patent uses preliminary scheduling actions. Transmission timing information is pre-calculated and stored before packets arrive, allowing the scheduler to simply retrieve and execute pre-determined transmission times without needing complex real-time compensation algorithms, thus reducing processing complexity while maintaining deterministic transmission guarantees.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4425896B1Deterministic stream transmission method and system, and electronic device
Publication Date: 2025.12.24 NEW H3C TECH CO LTD
  • EP4425896B1 patent drawingFigure 1~3
  • EP4425896B1 patent drawingFigure 4~5
  • EP4425896B1 patent drawingFigure 6~7

AI summary

Deterministic flow transmission methods and systems, and electronic devices are provided by the present application. In embodiments of the present application, the first service packet sent by the first transmission node within a certain scheduling cycle is specified to enter a certain cyclic scheduling queue of the second transmission node (that is, the specified cyclic scheduling queue), so as to ensure that the first service packet is scheduled and forwarded on time by the second transmission node. As such, even if there is jitter on the transmission link between the first transmission node and the second transmission node, due to both a scheduling cycle for the first transmission node to schedule and transmit the first service packet and a scheduling cycle for the second transmission node to schedule and transmit the first service packet can be directly determined, it can be ensured that the above-mentioned jitter has no influence on deterministic parameters of the first service packet (which is equivalent to de-jittering the above-mentioned jitter), and a deterministic flow transmission for the first service packet is realized.