Apparatus for and method of cable diagnostics utilizing time domain reflectometry
First Claim
1. A method of performing diagnostics on a channel including a cable using circuitry embedded in a communications transceiver without the need to use special cable measurement equipment, said method comprising the steps of:
- generating, in said communications transceiver, a programmed pulse based on a dynamic channel impulse response of said channel, wherein said pulse may be positive or negative;
transmitting said pulse from one end of said cable;
receiving a reflected signal and generating a plurality of sequences of samples therefrom;
ignoring an initial sequences of samples;
detecting and measuring the amplitude of positive and negative peaks present in said reflected signal;
determining diagnostic information about said cable based on the location and amplitude of said positive and negative peaks; and
identifying a topology for said cable.
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Accused Products
Abstract
A novel mechanism for performing high accuracy cable diagnostics. The mechanism utilizes time domain reflectometry (TDR) to detect and identify cable faults, perform estimations of cable length, identify cable topology, identify load and irregular impedance on metallic paired cable, such as twisted pair and coaxial cables. The TDR mechanism transmits pulses whose shapes are programmable and analyzes the signal reflections. The shapes of the pulses transmitted can be optimized in accordance with the channel characteristics. Further, the TDR mechanism is adapted to operative in the presence of high pass filters in the channel.
37 Citations
18 Claims
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1. A method of performing diagnostics on a channel including a cable using circuitry embedded in a communications transceiver without the need to use special cable measurement equipment, said method comprising the steps of:
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generating, in said communications transceiver, a programmed pulse based on a dynamic channel impulse response of said channel, wherein said pulse may be positive or negative; transmitting said pulse from one end of said cable; receiving a reflected signal and generating a plurality of sequences of samples therefrom; ignoring an initial sequences of samples; detecting and measuring the amplitude of positive and negative peaks present in said reflected signal; determining diagnostic information about said cable based on the location and amplitude of said positive and negative peaks; and identifying a topology for said cable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An apparatus embedded in a communications transceiver, said apparatus for performing cable diagnostics on a channel including a, comprising:
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a pulse generator coupled to said channel, said pulse generator operative to program a pulse based on a dynamic channel impulse response of said channel which is transmitted onto said cable; a peak detector coupled to said cable and operative to detect and measure the amplitude of positive and negative peaks present in a reflected signal; a memory coupled to said peak detector for storing peak location and amplitude information; and means for determining diagnostic information about said cable based on the location and amplitude of said positive and negative peaks.
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17. An apparatus embedded in a communications transceiver, said apparatus for performing cable diagnostics on a channel including a cable, said apparatus comprising:
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means for generating in said communications transceiver a programmed pulse based on a dynamic channel impulse response of said channel, wherein said pulse is transmitted from one end of said cable; means for receiving a reflected signal and generating a sequence of samples therefrom; means for detecting and measuring the amplitude of positive and negative peaks present in said reflected signal; and means for determining diagnostic information about said cable based on the location and amplitude of said positive and negative peaks.
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18. A communications transceiver having an embedded time domain reflectometry (TDR) diagnostic module and coupled to a channel including a cable, said transceiver comprising:
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a pulse generator coupled to said channel, said pulse generator operative to program a pulse based on a dynamic channel impulse response of said channel; a transmitter to transmit said pulse onto said cable; a receiver for receiving a reflected signal; a peak detector coupled to said cable and operative to detect and measure the amplitude of positive and negative peaks present in said reflected signal; a memory coupled to said peak detector for storing peak location and amplitude information; and means foe determining diagnostic information about said cable based on the location and amplitude of said positive and negative peaks.
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Specification