DSL Circuit AnnexA AnnexB POTS ISDN Compatibility
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Solution Overview
Problem
Current DSL circuit solutions require two different sets of circuits to support AnnexA and AnnexB modes, leading to a large number of board types and part numbers, as they are not compatible with both original POTS and ISDN services on a copper line.
Innovation Solution
A digital subscriber line circuit incorporating a line driver, echo cancellation module, transformer module, first high-pass filter, and bypassable high-pass filter, which allows for simultaneous support of AnnexA and AnnexB modes by selectively filtering signals to be compatible with both POTS and ISDN services, reducing the number of board types and part numbers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If two different sets of circuits are used to support AnnexA and AnnexB modes, then compatibility with POTS and ISDN services is achieved, but the number of board types and part numbers increases
Solution Approach 1:
The patent implements a universal DSL circuit that can operate in both AnnexA and AnnexB modes using the same hardware components. The circuit includes a line driver, echo cancellation module, transformer module, and high-pass filters that can be dynamically configured through control signals to support either mode, eliminating the need for separate dedicated circuits for each service type.
Solution Approach 2:
The patent employs dynamic switching mechanisms where control signals activate or deactivate specific circuit components based on the required operating mode. The high-pass filters and echo cancellation modules can be dynamically reconfigured to adapt to different frequency allocations for POTS/ISDN services, allowing a single static circuit to perform multiple functions.
2Reliability
If separate circuits are designed for AnnexA and AnnexB modes, then mode-specific performance is optimized, but manufacturing and inventory complexity increases
Solution Approach 1:
The patent designs a single universal circuit board that can be manufactured once and deployed for both AnnexA and AnnexB modes. The circuit incorporates switchable components and control logic that enable the same physical hardware to deliver mode-optimized performance, significantly reducing manufacturing variety and inventory requirements.
Solution Approach 2:
The patent achieves mode-specific optimization by dynamically changing circuit parameters such as filter cutoff frequencies and signal routing configurations rather than requiring different physical circuits. Control signals adjust these parameters to match the requirements of either AnnexA or AnnexB mode, maintaining performance while simplifying manufacturing.
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
The circuit effectively supports both AnnexA and AnnexB modes while being compatible with POTS and ISDN services on a copper line, reducing the complexity and number of board types and part numbers compared to prior art.
Implementation Method 1
The first high-pass filter is adapted to select a cut-off frequency point to normally send a downlink signal of AnnexA mode
Implementation Method 2
The bypassable high-pass filter is adapted to filter out an ISDN signal when being used in cooperation with an ISDN, and is bypassable and is adapted to receive an uplink signal of AnnexA mode when being used in cooperation with a POTS
Data Source
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AI summary
Embodiments of the present invention disclose a digital subscriber line circuit, including: a line driver, an EC module, a transformer module, a first high-pass filter, an impedance, and a bypassable high-pass filter. The transformer module is a high-pass filter, a receiving channel of the high-pass filter can receive an uplink signal of AnnexA and part of ISDN signals, and a sending channel of the high-pass filter can send a downlink signal of AnnexA. The first high-pass filter can send a downlink signal of AnnexA. The bypassable high-pass filter filters out an ISDN signal when being used in cooperation with an ISDN, and is bypassable and receives an uplink signal of AnnexA when being used in cooperation with a POTS. The embodiments of the present invention also disclose a digital subscriber line device. By using the embodiments of the present invention, both an AnnexA mode and an AnnexB mode are supported, and an original POTS service and ISDN service on a copper line are compatible.