Multilink DSL via Far-End Crosstalk Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In copper access networks, customers on longer loops experience lower achievable physical layer rates due to limitations in copper loop quality and length, which existing fiber-to-the-X deployments do not adequately address for legacy customers.
Innovation Solution
The implementation of a multilink digital subscriber line (DSL) system utilizing out-of-band far-end crosstalk (FEXT) coupling to create additional usable spectrum, allowing for higher rate services by sharing copper twisted pairs and establishing independent data links without requiring additional infrastructure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If fiber-to-the-X technology is deployed to improve rates, then customers on shorter copper loops achieve higher rates, but legacy customers on longer copper loops remain unaffected
Solution Approach 1:
The patent segments the communication channel by separating the direct link signal from the crosstalk signal. The direct link carries data between the CO and CPE, while the crosstalk signal (which was previously harmful interference) is extracted and used to establish an additional independent data link, effectively doubling the usable communication paths.
Solution Approach 2:
The patent converts the harmful crosstalk interference into a beneficial resource. By using vectoring technology to cancel crosstalk on the direct link, the system recovers the crosstalk signal and repurposes it to create a second data link, thereby transforming what was previously a degradation factor into an additional communication channel that serves legacy customers on longer loops.
2Reliability
If vectoring is used to cancel crosstalk, then direct link performance improves, but the crosstalk signal needed for the invention is eliminated
Solution Approach 1:
The patent applies preliminary vectoring processing to cancel crosstalk on the direct link before data transmission, ensuring high signal quality for the primary communication path. Simultaneously, it captures the crosstalk signal at the point of generation and processes it separately to establish the second data link, ensuring both the direct link and crosstalk link have adequate signal quality.
Solution Approach 2:
The patent introduces an intermediary processing stage that separates the crosstalk signal extraction from the direct link transmission. The vectoring processor acts as an intermediary that can selectively cancel crosstalk for the direct link while preserving or redirecting the crosstalk signal for use in the second data link, allowing both functions to coexist.
3Productivity
If multiple data links are established using crosstalk coupling, then service rates increase, but system complexity increases
Solution Approach 1:
The patent makes the existing copper infrastructure multi-functional by enabling it to carry both the direct link signal and the crosstalk link signal simultaneously over the same physical medium. The vectoring processor and signal extraction mechanisms are designed to handle multiple functions: canceling crosstalk for the direct link, extracting the crosstalk signal, and establishing the second data link, thereby increasing productivity without requiring additional physical infrastructure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances subscriber rates on longer copper loops, providing higher service rates to customers connected to the same binder, thereby justifying capital expenditures on new cabinet installations and improving overall network performance.
Implementation Method 1
utilizing out-of-band far-end crosstalk (FEXT) coupling to create additional usable spectrum
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A communication system, device and method for providing twisted pair multilink communications are provided. The system includes a first operator end terminal unit configured to couple to a first customer premises equipment (CPE) via a first twisted pair and configured to exchange first communications with the first CPE for transmission of a first part of traffic data of the first CPE over a first communication link on a first twisted pair. And the system includes a second operator end terminal unit configured to couple to a second CPE via a second twisted pair and configured to exchange second communications with the first CPE for transmission of a second part of traffic data of the first CPE over a second communication link that is a crosstalk link induced by the second twisted pair to the first twisted pair.