Acterna LLC

Digital Communications Corporation

Ever-gard Vehicle Security Systems, Inc.

Other

Hughes Electronics Corporation

Paul Francis Wyar

Robert L Richmond

Richard G Peters

John Garfield Williams

David R Smith

David Johnson

Richard Liberman

Greg Quiggle

Duane Eareckson

Larry Hartman

An adaptive pulse width (APW) Time Domain Reflectometer (TDR) comprises an enhancement to the standard Pulse TDR by adjusting the effective pulse width as a function of time. Improved resolution for a large range of cable lengths is obtained, as well as allowing an all-in-one view of the processed return signal trace.

Adaptive pulse width time domain reflectometer

In a system and method for testing and displaying the abnormalities, includes opens, shorts, bridged-taps and wet sections, of a copper pair line for xDSL service use, the abnormalities are amplified and normalized so as to be displayed within a predetermined observation range. The normalization steps include piecewise gaining and biasing the reflected pulse of various gains to create a first normalized reflected trace which match the reflected traces within a predetermined observation range and thereby constitute a total smooth curve; and amplifying the first normalized reflected trace according to a function of time to create a second normalized reflected trace so as to eliminate an exponential gain decay curve of a no-fault copper pair line with the same predetermined characteristic parameters from the first normalized reflected trace to thereby obtain a second normalized reflected trace showing any amplified abnormalities.

System and method for providing a time varying gain TDR to display abnormalities of a communication cable or the like

In a system and method for determining the suitability of a copper pair line for xDSL service use, characteristic parameters of a copper pair line to be tested are measured. These characteristics include a wire gauge, length, and temperature of the copper pair line. In addition, characteristics such as the presence of short circuits, longitudinal balance, the presence of load coils, wideband noise and loop attenuation are tested for the copper pair line. A plant map of the copper pair line is then determined based on the measured and tested characteristics. Using the above characteristics and the plant map of the copper pair line, a transfer function representative of the plant map is determined which is then used to analyze and thereby qualify the copper pair line.

System and method for single-ended line analysis for qualification and mapping

A method and apparatus for testing telephone equipment for longitudinal balance. A signal generating circuit places a test signal at a certain frequency on the tip and ring wires of a telephone line. The telephone line is monitored and the signals on the tip and ring wires are measured and compared against each other. The frequency is gradually increased in set increments until the test frequency is in the megahertz range.

Apparatus and method for a wide band spectral balance measurement

A redundant system, such as a redundant-modem system, having a plurality of similar components capable of operating independently of each other. At least one of the components serves as a spare component. The system further includes a plurality of switches connected to the inputs and outputs of the components such that the inputs and outputs of each of the components may be rerouted through the component operating as the spare. When operating as a spare, a component monitors status information received from the other components and detects when one of the other components has failed. When one of the components has failed, the component acting as a spare controls the switches such that the spare component (,) replaces the failed component.

Complexity reduction system and method for integrated redundancy switchover systems

An alarm system for an automotive vehicle including direct coupled input connections which provide a voltage proportional to the amount of current interchanged between, the battery and the electrical system of the vehicle. An arming circuit is responsive to the voltage and arms the burglar alarm only when less than a predetermined current is interchanged between the battery and the electrical system. An alarm circuit produces an alarm when the alarm system is armed and more than a predetermined amount of current is drawn from the battery.

Automotive burglar alarm that recycles after its initial alarm production

An alarm system for an automotive vehicle including direct coupled input connections which provide a voltage proportional to the amount of current interchanged between the battery and the electrical system of the vehicle. An arming circuit is responsive to the voltage and arms the burglar alarm only when less than a predetermined current is interchanged between the battery and the electrical system. An alarm circuit produces an alarm when the alarm system is armed and more than a predetermined amount of current is drawn from the battery.

Automotive burglar alarm system using direct current sensing

An on-line channel monitor, for measuring E.sub.b /N.sub.O, measures the quality of a communication channel while the channel is in use. The channel monitor employs a soft-decision demodulator so as to compare analog signal levels of an AGC compensated signal in a demodulator with the desired signal level. Deviations, termed pseudo-errors, are counted and the number of counts integrated. The result is employed to drive a meter calibrated in terms of E.sub.b /N.sub.O.

On-line channel quality monitor for a communication channel

The digital demodulator produces an information bearing analog signal which is controlled in peak-to-peak amplitude. The signal is coupled to a soft-decision demodulator which provides a multi-bit output representative of magnitude (polarity and amplitude) of the analog signal at a rate determined by the symbol clock derived from the digital demodulator. Logic means produces a logic signal of a first or second type in response to selected multi-bit outputs of the soft-decision demodulator. A logic output of the first type is produced if either the multi-bit output represents an analog signal of one polarity and amplitude greater than a predetermined amplitude, or if the multi-bit output represents an analog signal of the other polarity and amplitude less than an equal predetermined amplitude of the other polarity. The logic output is coupled to an integrating means which produces a control signal representative of deviations of the logic signal of the first type from 50% duty cycle. The deviation from 50% duty cycle determines the amplitude of the DC offset, and the polarity of the deviation determines the polarity of the offset. The output of the detector can be used in a feedback loop to eliminate the DC offset by coupling the control signal to a summing junction, to which is also coupled the analog signal.

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Mt. Airy, MD, United States of America

Paul Francis Wyar