General Instrument Corporation

Motorola Corporation

Arris Technology, Inc.

General Information Corporation

Motorola Mobility LLC

Arris Enterprises LLC

Andrew Wireless Systems Gmbh

Google Technology Holdings LLC

Arris International IP Ltd

Michael Jaimie Cooper

Robert J Thompson

Charles Sidney Moore

John L Moran, Iii

John L Moran

Charles S Moore

Marc L Morrissette

Brian K Thibeault

Stephen Schroeder

Mark Charles Miner

Robert G Uskali

Patrick D Smith

Richard C Wade

Daniel Ryan

Wei-Hung Hui

Keith M Conger

Veronica M Lobo

Poth Boontor

Thomas R Keske

John Leo Moran

John L Iii Moran

John L Moran Iii

Daniel T Ryan

Iii Moran John L

John Leo Iii Moran

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

Logical channels in a network are automatically be configured by using measured network parameters. The measured network parameters are determined in cooperation with the network elements without interruption of active communication services. The network parameters include upstream or downstream modulation error ratio (MER), upstream or downstream signal to noise ratio (SNR), upstream or downstream microreflections, upstream transmit level, downstream receive power level, cable modem type (DOCSIS 1.0,1.1,2.0), functional capabilities (e.g., VoIP, 256QAM, etc), network element location with in a cable plant (e.g., node location or amplifier cascade depth), network element manufacturer, or type of services provided by the network element (including telephony versus data). An interactive display is provided to an operator which enables analysis of communication parameters, including modulation profiles and channel performance.

Method and apparatus for configuring logical channels in a network

A method and computing device receives data packets on an upstream bonding group in full service mode, where the upstream bonding group includes a set of channels and each channel has a transmission quality. The method detects that a select channel in the set of channels is impaired when the transmission quality of the select channel is below a threshold value, and transitions the receiving of the data packets from full service mode to partial service mode by disabling data grant scheduling on the select channel. The method monitors the select channel using a spectrum management method while the receiving of the data packets is in partial service mode. The method transitions the receiving of the data packets from partial service mode to full service mode when a result from the spectrum management method indicates that the select channel can transmit data packets error free.

Upstream channel bonding partial service using spectrum management

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

Instability resulting from non-linear impairments is detected and an equalizer of an end device is reset. An equalization instability threshold is retrieved from a data storage device. An equalization parameter for the end device is monitored and, if the equalization parameter exceeds the equalization instability threshold, the equalizer is reset.

Monitoring instability and resetting an equalizer

A network element is identified from among a plurality of network elements to be used to test parameters of a network. The use of one network element to test the network provides more reliable results than using random communications from a plurality of network elements. The test network element is identified using testing pool definitions which may be provided by a network operator. The testing procedure using the single network element may use multiple pings to reduce the affect of transient responses on the network.

Method and apparatus for selecting a network element for testing a network

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.

Efficient use of trusted third parties for additional content-sharing security

Preamble length of burst communication signals dynamically changed to compensate in changes to linear distortion of a communication channel. Pre-equalization coefficients are provided to network element which pre-equalize communications with the CMTS. Long preamble lengths are used for a select few communications while short preamble lengths are used for the rest of the communication signals. When change in distortion characteristics is detected, a station maintenance is performed on the affected network element and new pre-equalization coefficients are determined and provided to the network element. Alternatively, all communications may be provided with long preamble lengths and communications may continue while the CMTS determines new pre-equalization coefficients.

Method and apparatus for dynamically changing the preamble length of a burst communication

The present methods and systems provide spectrum management for enhancing upstream performance for cable networks. According to one embodiment, a method of enhancing upstream performance in a cable network includes the steps of measuring performance of an upstream channel at a first data signaling rate; determining whether the upstream channel supports a second data signaling rate based on the performance; and selectively transitioning to the second data signaling rate based on said determination. The second data signaling rate is a higher rate than the first data signaling rate.

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Marietta, GA, United States of America

Michael Jaimie Cooper