VDSL Transmit Power Spectrum Adjustment for Crosstalk Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current DSL network technologies face challenges in optimizing transmit power spectra due to crosstalk issues, particularly in scenarios with distributed VDSL COs, leading to suboptimal use of transmission capacity and interference between ADSL and VDSL systems.
Innovation Solution
A DSL transceiver device with a transmit/receive modem and a transmit power spectrum adjuster that determines a modified attenuation measure based on the length of cables connecting different subscriber devices, allowing for adjusted transmit power spectra to equalize interference and maximize transmission capacity across varying line lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If all subscriber devices transmit with the same transmit power spectral density, then the transmission setup is simple, but CPEs closer to the CO cause high crosstalk interference to CPEs further away
Solution Approach 1:
The patent applies parameter changes by adjusting the transmit power spectral density based on cable length. Instead of using a fixed transmission power for all devices, the system modifies the power parameter dynamically according to the distance from the CO, thereby reducing crosstalk from nearby devices while maintaining adequate signal strength for distant devices.
2Object-affected harmful factors
If transmit power spectral density is reduced for shorter lines to reduce crosstalk, then interference is minimized, but transmission capacity is not optimized
Solution Approach 1:
The patent implements local quality by applying different transmit power spectral density adjustments to different cable segments based on their specific characteristics. Each cable length category receives a tailored power adjustment rather than a uniform reduction, optimizing transmission capacity for each local segment while collectively minimizing overall crosstalk interference.
3Adaptability or versatility
If distributed VDSL COs are implemented, then service coverage is improved, but interference between ADSL and VDSL systems increases
Solution Approach 1:
The patent applies segmentation by dividing the cable network into distinct segments based on length categories (e.g., first cable group with shorter lengths, second cable group with longer lengths). This segmentation allows for differentiated power spectral density management in each segment, enabling the system to accommodate multiple CO types while controlling interference through localized power adjustments.
4Device complexity
If standard UPBO method is used assuming single CO location, then implementation is straightforward, but it does not account for distributed CO scenarios
Solution Approach 1:
The patent implements dynamics by making the UPBO method adaptive to different CO configurations. The system dynamically determines cable length categories and applies appropriate power adjustments based on the actual network topology, whether single CO or distributed COs. This dynamic approach maintains operational simplicity while providing versatility across different deployment scenarios.
Data Source
AI summary
A UPBO is performed based on an attenuation of a first VDSL-cable connecting a first VDSL-CPE and a first VDSL-CO, and also based on an attenuation or electrical length of cable pieces between said first VDSL-CO and a further distant second VDSL-CO. Further, an extended DPBO for the first VDSL-CO is described not only regarding ADSL-cables originating from an ADSL-CO but also VDSL-cables from the further distant second VDSL-CO.