Dynamic Time Adjustment for FTTdp Near-End Crosstalk Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In FTTdp networks using G.fast technology, asynchronous upstream and downstream transmission times lead to near-end crosstalk, degrading the performance of vectoring technologies and resulting in low line rates and unstable performance due to impedance mismatch between sending and receiving states of transceivers.
Innovation Solution
A dynamic time adjustment method and apparatus that adjust the lengths of upstream and downstream transmission durations based on traffic conditions, using a processor and communications interface to send indication messages and adjust transmission configurations, ensuring synchronized transmission states across multiple transceivers to mitigate crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dynamic time assignment adjusts upstream and downstream transmission durations based on traffic conditions, then transmission efficiency is improved, but asynchronous transmission states cause near-end crosstalk
Solution Approach 1:
The network side device sends indication information to the user side device in advance before adjusting the transmission duration, allowing the user side device to prepare for the time adjustment and synchronize its transmission timing accordingly, preventing near-end crosstalk caused by asynchronous states
Solution Approach 2:
The system uses feedback mechanisms where the network side device monitors transmission states and sends indication information to user side devices to coordinate timing adjustments, ensuring that all devices transition to new transmission durations in a synchronized manner that eliminates crosstalk
2Object-generated harmful factors
If the transceiver remains in sending state during transition, then near-end crosstalk is avoided, but impedance mismatch degrades vectoring technology performance
Solution Approach 1:
The system sends indication information in advance to coordinate the transition timing, ensuring that all transceivers switch states simultaneously rather than having some in sending state and others in receiving state, thereby eliminating impedance mismatch while still preventing near-end crosstalk
Solution Approach 2:
The system dynamically adjusts the transmission duration parameters and coordinates state transitions by changing the timing parameters of all transceivers simultaneously, ensuring that impedance characteristics remain consistent across the network during dynamic time assignment
Data Source
Figure 1A~2
Figure 3~4
Figure 5
AI summary
This application discloses a dynamic time adjustment method, apparatus, and system, and pertains to the field of network communications. The method includes: determining a length of a new downstream transmission duration; updating lengths of upstream and downstream transmission durations based on the determined length of the new downstream transmission duration; and keeping silent or sending an idle symbol or another symbol with known content in a transition zone until all user-side devices complete updating of the lengths of the upstream and downstream transmission durations, where the transition zone is an additional zone of the new downstream transmission duration compared with a currently used downstream transmission duration, or an additional zone of a new upstream transmission duration compared with a currently used upstream transmission duration. Keeping silent or sending an idle symbol or another symbol with known content in these zones can avoid affecting normal data transmission.