Method of characterizing impairments detected by equalization on a channel of a network
First Claim
1. An automated method of characterizing impairments detected by equalization on a channel of a network, comprising, in at least one processor:
- estimating a first equalization stress of an observed channel equalization response of an end device of the network required for equalization;
calculating a second equalization stress of a channel equalization response of the end device mathematically based on the observed channel equalization response and a removal of a suspected impairment from the network;
repeating said calculating step separately for each of a plurality of suspected impairments stored in a database of suspected impairments; and
determining a highest ranking suspected dominant impairment from the database of suspected impairments that, if removed from the network, would provide a greatest reduction of an equalization stress of a channel equalization response of the end device;
wherein equalization stress is measured by at least one metric selected from a group of metrics consisting of Main Tap Compression (MTC), Non Main Tap to Total Tap Energy Ratio (NMTTER), Pre Main Tap Energy Ratio (PreMTTER), Post Main Tap Energy Ratio (PostMTTER), Pre/Post Energy Symmetry Ratio (PPESR), and Pre/Post Tap Symmetry Ratio (PPTSR) wherein, during said determining step, an ordered series of next highest ranking suspected dominant impairments are identified from the database of suspected impairments that, if removed from the network, would provide next greatest reductions of the equalization stress of the channel equalization response of the end device.
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Abstract
An automated method of characterizing distortion detected by equalization on a channel of a network is provided. Equalization stress of an observed channel equalization response of an end device of the network is estimated, and equalization stress is calculated for a theoretical channel equalization response of the end device mathematically based on the observed channel equalization response and a theoretical removal of a suspected impairment from the network. The above referenced calculating step is separately repeated for each of a plurality of suspected impairments stored in a database of suspected impairments. A highest ranking suspected dominant impairment is determined from the database of suspected impairments such that removal of the highest ranking suspected dominant impairment from the network would provide a greatest reduction of equalization stress of a channel equalization response of the end device.
316 Citations
16 Claims
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1. An automated method of characterizing impairments detected by equalization on a channel of a network, comprising, in at least one processor:
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estimating a first equalization stress of an observed channel equalization response of an end device of the network required for equalization; calculating a second equalization stress of a channel equalization response of the end device mathematically based on the observed channel equalization response and a removal of a suspected impairment from the network; repeating said calculating step separately for each of a plurality of suspected impairments stored in a database of suspected impairments; and determining a highest ranking suspected dominant impairment from the database of suspected impairments that, if removed from the network, would provide a greatest reduction of an equalization stress of a channel equalization response of the end device; wherein equalization stress is measured by at least one metric selected from a group of metrics consisting of Main Tap Compression (MTC), Non Main Tap to Total Tap Energy Ratio (NMTTER), Pre Main Tap Energy Ratio (PreMTTER), Post Main Tap Energy Ratio (PostMTTER), Pre/Post Energy Symmetry Ratio (PPESR), and Pre/Post Tap Symmetry Ratio (PPTSR) wherein, during said determining step, an ordered series of next highest ranking suspected dominant impairments are identified from the database of suspected impairments that, if removed from the network, would provide next greatest reductions of the equalization stress of the channel equalization response of the end device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for characterizing impairments detected by equalization on a channel of a network, comprising:
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one or more processors communicatively coupled to the network, wherein the network has a headend with a cable modem termination system (CMTS); the one or more processors configured to estimate a first equalization stress of an observed channel equalization response of a cable modem of the network required for equalization; the one or more processors further configured to calculate a second equalization stress of a channel equalization response of the cable modem mathematically based on the observed channel equalization response and a removal of a suspected impairment from the network; the one or more processors further configured to repeat said calculating step separately for each of a plurality of suspected impairments stored in a database of suspected impairments; and the one or more processors further configured to determine a highest ranking suspected dominant impairment from the database of suspected impairments that, if removed from the network, would provide a greatest reduction of an equalization stress of a channel equalization response of the cable modem; wherein a communication protocol used by the cable modem and CMTS for equalization is Data Over Cable System Interface Specification (DOCSIS), and a modulation scheme used by the network is quadrature amplitude modulation (QAM); and wherein equalization stress is measured by at least one metric selected from a group of metrics consisting of Main Tap Compression (MTC), Non Main Tap to Total Tap Energy Ratio (NMTTER), Pre Main Tap Energy Ratio (PreMTTER), Post Main Tap Energy Ratio (PostMTTER), Pre/Post Energy Symmetry Ratio (PPESR), and Pre/Post Tap Symmetry Ratio (PPTSR) wherein, during said determining step, an ordered series of next highest ranking suspected dominant impairments are identified from the database of suspected impairments that, if removed from the network, would provide next greatest reductions of the equalization stress of the channel equalization response of the end device.
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10. At least one non-transitory computer readable storage medium having computer program instructions stored thereon that, when executed by at least one processor, cause the at least one processor to perform the following operations:
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estimating a first equalization stress of an observed channel equalization response of an end device of a network; calculating a second equalization stress of a channel equalization response of the end device mathematically based on the observed channel equalization response and a removal of a suspected impairment from the network; repeating said calculating step separately for each of a plurality of suspected impairments stored in a database of suspected impairments; and determining a highest ranking suspected dominant impairment from the database of suspected impairments that, if removed from the network, would provide a greatest reduction of an equalization stress of a channel equalization response of the end device; wherein equalization stress is measured by at least one metric selected from a group of metrics consisting of Main Tap Compression (MTC), Non Main Tap to Total Tap Energy Ratio (NMTTER), Pre Main Tap Energy Ratio (PreMTTER), Post Main Tap Energy Ratio (PostMTTER), Pre/Post Energy Symmetry Ratio (PPESR), and Pre/Post Tap Symmetry Ratio (PPTSR) wherein, during said determining step, an ordered series of next highest ranking suspected dominant impairments are identified from the database of suspected impairments that, if removed from the network, would provide next greatest reductions of the equalization stress of the channel equalization response of the end device. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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Specification