DS-TT Synchronization via NW-TT Residence Time in 5G TSN
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in determining the DS-TT ingress residence time and synchronizing the timing of the DS-TT module with the TSN Grandmaster (GM) in 5G wireless communication systems, which is not adequately addressed by existing standards.
Innovation Solution
A method is provided to determine the frequency rate ratio between the 5G and TSN time domains, using the NW-TT module to calculate the DS-TT ingress residence time, and synchronize the DS-TT module with the TSN GM by determining the frequency rate ratio and using it to adjust the DS-TT's timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the DS-TT module uses standard PTP/gPTP synchronization protocols, then basic time synchronization is achieved, but high precision synchronization (sub-microsecond level) required for deterministic data transfer cannot be guaranteed
Solution Approach 1:
The patent introduces an intermediary mechanism where the NW-TT module acts as a mediator between the TSN GM and DS-TT module. The NW-TT calculates the residence time and provides correction information to the DS-TT, enabling high precision synchronization without requiring the DS-TT to directly implement complex PTP/gPTP protocols. This intermediary approach bridges the gap between standard protocols and high precision requirements.
Solution Approach 2:
The patent applies preliminary action by pre-calculating the residence time at the NW-TT module before the synchronization message reaches the DS-TT. The NW-TT determines the residence time based on the difference between the time the sync message is received at the NW-TT ingress port and the time it is received at the DS-TT ingress port. This pre-calculated correction information is then used by the DS-TT to achieve high precision time synchronization.
2Device complexity
If the DS-TT module directly synchronizes with TSN GM without NW-TT intervention, then synchronization complexity is reduced, but accuracy of residence time calculation deteriorates
Solution Approach 1:
The NW-TT module serves as an intermediary that performs the complex residence time calculation on behalf of the DS-TT module. The NW-TT has access to timing information from both the TSN GM and the DS-TT, allowing it to accurately calculate the residence time. This approach maintains low complexity at the DS-TT while achieving high precision through the intermediary NW-TT.
3Ease of operation
If frequency rate ratio calculation is not performed, then synchronization process is simpler, but clock frequency synchronization between 5G and TSN domains cannot be achieved
Solution Approach 1:
The patent applies parameter changes by calculating and applying the frequency rate ratio between the 5G time domain clock and the TSN time domain clock. The NW-TT determines this ratio and uses it to adjust the DS-TT's timing, enabling the DS-TT to synchronize with the TSN GM despite operating in different time domains. This parameter adjustment allows the system to handle frequency differences while maintaining synchronization simplicity at the DS-TT level.
Data Source
AI summary
A method of time synchronization between a DS-TT module inside a logical TSN bridge of a communication network with a TSN Grandmaster (GM) in a TSN Time Domain of the communication network. The method comprises, at a NW-TT module inside the logical TSN bridge, determining a frequency rate ratio between a Time Domain clock frequency (f5GS) and a TSN Time Domain clock frequency (fTSN). Then, using the frequency rate ratio and respective times of receipt of a TSN GM synchronization message at an ingress port of the NW-TT module and at an ingress port of the DS-TT module to determine a DS-TT ingress residence time (RDS-TT). Then, using the RDS-TT to synchronize the DS-TT module with the TSN GM.