General Instrument Corporation

Arris Technology, Inc.

Arris Enterprises LLC

General Information Corporation

Charles Sidney Moore

Robert J Thompson

Michael Jaimie Cooper

John L Moran, Iii

John L Moran

Marc L Morrissette

Brian K Thibeault

John M Gatewood

Douglas Alexander Ridley

Matthew J Kuester

Nicholas E Burmylo

Rick Thomas Macias

Portable skid assemblies are shown and disclosed. In some embodiments, the portable skid assemblies include a frame having two or more pockets sized to receive the fork of a forklift, telehandler, or pallet jack. The portable skid assemblies additionally include a support assembly having a base attached to the frame and at least one support member that moves vertically relative to the base between a retracted position suitable for at least one of storage or transport, and an extended position where the skid assembly is configured to communicate wireless signals.

Portable skid assemblies

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.

Method of characterizing impairments detected by equalization on a channel of a network

The dynamic range of an optical link in a network is determined by simultaneously transmitting signals from two network elements at first and second frequencies, which create a combined signal at a third frequency. The transmission power levels of selected network elements is successively increased until the measured power from the third frequency no longer changes in a predictable manner, at which point the upper limit of the dynamic range of the optical link is determined.

Method and apparatus for determining the dynamic range of an optical link in an HFC network

A method and apparatus for updating equalization coefficients of an adaptive pre-equalizer of a network element are provided. The method includes monitoring a communications channel to measure distortion of a communications signal received from the network element and detecting whether a transient impairment is present in the communication signal. When a transient impairment is not detected to be present, a pre-equalization coefficient update is transmitted to the network element. However, when a transient impairment is detected to be present, at least selected ones of the pre-equalization coefficients are scaled before the update is transmitted to the network element or the update is withheld from being transmitted to the network element. An apparatus is also disclosed.

Method and apparatus for updating equalization coefficients of adaptive pre-equalizers

The presence of micro-reflections is determined in a network by determining micro-reflections from amplifier and diplex filter impedance mismatches and micro-reflections from drop cable impedance mismatches. The micro-reflections from impedance mismatches are determined by instructing network element to transmit a test signal at a first symbol rate and a first resolution for amplifier and diplex filter impedance mismatches and a second frequency with a second symbol rate and second resolution for micro-reflections from drop cable impedance mismatches. The tests are performed with several frequencies and the channels with the least micro-reflections are identified.

Method and apparatus for determining micro-reflections in a network

A system estimates impairment contributions for upstream communications in a cable television system. The system receives equalization coefficients used by end devices in the cable television system. The equalization coefficients are used by equalizers to mitigate distortion in upstream channels for the end devices. The system analyzes the coefficients based on impairment thresholds to determine whether impairment problems exist and to identify the types of impairment problems that exist.

Using equalization coefficients of end devices in a cable television network to determine and diagnose impairments in upstream channels

A logical channel is configured to match a modulation profile of an active channel. A network element is assigned to the logical channel and a ping request is sent to the network element. A response from the network element is measured, such as measuring the MER. The modulation profile is increased in the logical channel and another ping request is sent to the network element. The response is measured again, and the process is repeated until a non-linearity is detected in the response. The acceptable modulation profiles are indicated before the non-linearity is detected in the response.

Method and apparatus for determining modulation levels that are supported on a channel

Methods are described for identifying a dominant impairment on a communication channel impaired by an interference issue. The methods include systematic examination of total power loading, systematic examination of signal power reduction, statistical examination of communication channel noise power, and systematic examination of interleaver effectiveness. Each relates to automatically diagnosing and characterizing distortion-based interference issues by monitoring the performance of a communication channel during a testing procedure. These methods enable a technician or engineer to remotely diagnose distortion-based interference issues relatively quickly without having to use external test equipment and without having to deploy technicians to various locations within the cable plant. A system by which these methods can be implemented is also disclosed.

Methods and system for determining a dominant impairment of an impaired communication channel

The available modulation schemes of a network are analyzed to determine which ones contain excessive phase noise or narrowband interference. A network element is selected and assigned to a test channel at a first modulation scheme at a predetermined power level to achieve a predetermined PER. The network element transmits a test signal and the network controller measures the signal to noise ratio (SNR) in the received test signal. If the SNR is not within a predetermined tolerance range of an estimated SNR for the modulation scheme at the predetermined PER, the modulation scheme is determined to have excessive phase noise or narrowband interference. Each available modulation scheme is tested by instructing the network element to transmit the test signal using each modulation scheme and assigning the power level of each modulation scheme. The suitable modulation schemes may be determined.

Method and apparatus for characterizing modulation schemes in an HFC network

Network elements are identified as being connected to optical nodes by instructing two network elements in a spectrum group of the CMTS to transmit at frequencies fand f, respectively. Frequencies fand fare selected such that they produce intermodulation distortions (intermods) in the laser transmitter at fwhen combined. If intermods are produced which exceed a predetermined threshold, then the two network elements are determined to be on the same node. If the total power of the signal by the laser transmitter exceeds an impact threshold, then the test is stopped and new network elements are selected for testing.

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Langhorne, PA, United States of America

Charles Sidney Moore