Viavi Solutions Inc.

Wavetek Corporation

Jds Uniphase Corporation

Acterna LLC

Other

Wavetek Wandel Goltermann

Daniel Keith Chappell

Loren R Eggert

Adam D Gray

Richard Earl Jones, Jr

David W Jones

Ben Maxson

Ching-Chang Liao

Kyle Harris

Timothy R Voght

Pingnan Shi

Walter L Miller

Gregory W Massey

Michael D Gotwals

Jim Walsh

Andrew E Bowyer

Cinna Soltanpur

Douglas J Franchville

Adam A Nowotarski

Vincent Michael Zipparo

Michael J Kunczt

Kelly Watts

Brett Emsley

Eddie B Gaines

David Hering

Walter Miller

A method, apparatus and system for per-channel MER calibration and determination on a multi-channel receiver.

Per-channel modulation error ratio (MER) calibration and determination on a multi channel receiver

A CMTS may instruct one or more cable modems to transmit an upstream test signal with a particular preamble (and or any other type of signature) in the upstream transmission bandwidth. The preamble may be within a significant band of the upstream transmission bandwidth. A leakage detection device may be brought in the vicinity of the cable network to listen for various signals. The leakage detection device may filter received signals to retain the portions thereof within a desired limited band and further filter the band-limited signals to reduce noise, e.g., removing the payload following the preamble. A correlation filter in the leakage detection device may compare the pattern in the band-limited filtered signal with a stored preamble. If there is a match, the leakage detection device may generate an indication that leakage is detected in the upstream transmission.

Upstream signal leakage detection in high-split cable network

A method and an apparatus providing common path distortion (CPD) detection from a field instrument, particularly when the source of the common path distortion is at a portion of the network beyond the subscriber's tap.

Method and apparatus providing common path distortion (CPD) detection from a field instrument

Systems and methods for detecting leakage in a cable network system are disclosed. In at least some illustrative embodiments, a system may include a digital tagger operable to generate a digital tag including a chirp signal configured to be placed on a downstream signal path of the cable network system, and a cable network test instrument configured detect the digital tag in wireless signal data received from the cable network system when a point of ingress is presented in the cable network system. The network test instrument may be operable to provide a user-perceptible indication when the digital tag is detected to inform a technician or other user that a flaw in the cable network system is nearby.

Systems and methods for detecting leakage in a cable network system

A test instrument connectable to a cable television (CATV) network to provide a high resolution time domain reflectometry (TDR) in a fault location measurement is disclosed. The test instrument may have a port connectable to a test point in the CATV network. The test instrument may also have a processing circuit to perform a calibration measurement and a fault location measurement by transmitting frequency-chirped probe pulses into a closed calibration circuit within the test instrument, and receiving return signals at an analog-digital converter in the test instrument. The processing circuit may resample the calibration measurement and the fault location measurement at a high sampling rate, cross-correlate the fault location with the calibration measurement to generate a cross-correlation TDR waveform, and generate a new TDR waveform using a refinement processing technique to remove echoes from the cross-correlation TDR waveform.

High resolution time domain reflectometry (TDR) in fault location measurement in a cable network

A network test instrument is operable to conduct sweep tests with a cable modem termination system having a distributed architecture. Through signaling performed via a telemetry channel between the network test instrument and a sweep server, the network test instrument can initiate the sweep test. The sweep server communicates with the cable modem termination system to facilitate the sweep test between the network test instrument and the cable modem termination system.

Upstream sweep test with sweep server signaling

A TDR technique for performing in-service distance-to-fault measurements in cable TV networks is disclosed. Using a cable network tester configured to generate chirped probe pulses and to perform pulse-matched filtering and averaging of received echoes, network faults may be detected without interfering with the downstream reception. The probe pulse transmission may be timed to take advantage of the error correction coding in the network.

Distance to fault measurements in cable TV networks

Methods and devices for characterization of repetitious noise in cable networks are disclosed. A frequency band of interest is identified, a time trace of a signal parameter within the frequency band is obtained, and an autocorrelation of the time trace is computed to detect repetitious noise. The repetition frequency can serve as an indicator of the noise source type, and thus it can assist in noise segmentation.

Characterizing ingress noise

A network test instrument is operable to generate an interference profile for a bursty channel of a cable television network. Frequency spectrum data of a received signal is cross-correlated with predetermined frequency spectrum data to identify traces representative of noise. The interference profile may be built from the traces.

Interference profile of a bursty channel

Apparatus and method are provided for obtaining an upstream signal spectrum as it was during a time of transmission of a received upstream data packet. The apparatus includes an analog-to-digital converter (ADC), a packet detector coupled to ADC, and a spectrum calculation unit coupled to the ADC and the packet detector. In operation, the spectrum calculation unit computes a spectrum of the digitized upstream signal as it was between the start and end times of the first packet. As a result, the obtained spectrum is representative of a condition of the transmission path during transmission of the upstream data packet.

Cable network spectral measurement during upstream packet transmission

Growing community of inventors

Greenwood, IN, United States of America

Daniel Keith Chappell