Cable Gateway Digital Filter for DOCSIS MoCA Interference
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Solution Overview
Problem
The increasing demand for high-speed internet access and streaming services in cable networks leads to conflicts between DOCSIS 3.1 downstream signals and MoCA signals, causing interference due to overlapping frequency spectra in the upper spectrum.
Innovation Solution
A cable network gateway that converts DOCSIS 3.1 downstream signals to digital, low-pass filters to attenuate the upper spectrum, and combines them with MoCA signals to prevent interference, ensuring seamless communication within the home.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If DOCSIS 3.1 downstream signals are transmitted in the cable network, then high-speed internet access is improved, but interference with MoCA signals occurs due to overlapping frequency spectra
Solution Approach 1:
The patent extracts and removes the harmful upper spectrum components (1000-1200 MHz) from the DOCSIS 3.1 downstream signal using digital filtering. This extraction eliminates the interference with MoCA signals while preserving the beneficial lower spectrum components that carry high-speed internet data, thus resolving the contradiction between maintaining high internet speed and preventing signal interference
Solution Approach 2:
The patent applies local quality by differentially treating different frequency portions of the DOCSIS signal. The lower spectrum (54-960 MHz) is preserved with full quality for high-speed internet, while the upper spectrum (1000-1200 MHz) is attenuated to prevent MoCA interference. This localized quality adjustment allows simultaneous operation of both DOCSIS 3.1 and MoCA without interference
2Reliability
If the upper spectrum is attenuated to prevent MoCA interference, then signal compatibility is improved, but some bandwidth is lost
Solution Approach 1:
The patent changes the frequency domain parameters of the DOCSIS 3.1 signal by applying digital filtering that selectively attenuates the upper spectrum (1000-1200 MHz) while preserving the lower spectrum (54-960 MHz). This parameter change creates a modified signal spectrum that is compatible with MoCA operation, achieving reliable multi-standard coexistence with acceptable bandwidth utilization
Data Source
AI summary
A cable network gateway receives a downstream broadband signal via service provider cabling at an interface. An Analog to Digital Converter (ADC) converts the downstream broadband signal to a digital downstream broadband signal. A digital filter attenuates an upper spectrum from the digital downstream broadband signal to produce a filtered digitized downstream broadband signal. An in-home communications transceiver produces a digital in-home communications signal that overlaps the upper spectrum. Summing circuitry sums the filtered digitized downstream broadband signal with the digital in-home communications signal to produce a combined digital signal. A Digital to Analog Converter (DAC) converts the combined digital signal to a combined analog signal and an in-home cable interface transmits the combined analog signal via in-home cabling. The downstream broadband signal may be a Data over Cable System Interface Specification (DOCSIS) 3.0/3.1 signal and the digital in-home communications signal comprises a Multimedia over Coaxial Alliance (MoCA) signal.