Patent ID: 7859271

Claim:
A method comprising: determining a length of a lossy electrical cable using a time-domain reflectometry (TDR) technique, wherein said determining the length of the lossy electrical cable using the TDR technique includes: sending an electrical pulse into the lossy electrical cable, wherein the electrical pulse comprises a leading edge portion and a non-leading edge portion, wherein the leading edge portion comprises a positive exponential waveform, wherein the positive exponential waveform maintains its shape during transmission through the lossy electrical cable, wherein the non-leading edge portion does not maintain its shape during transmission through the lossy electrical cable; and detecting a reflected signal in response to the electrical pulse, wherein the reflected signal is due to presence of an impedance discontinuity at an end of the lossy electrical cable, wherein the reflected signal comprises a leading-edge portion and a non-leading edge portion, wherein the leading-edge portion of the reflected signal comprises the positive exponential waveform; determining a time of flight between the positive exponential waveform within the leading edge portion of the electrical pulse and the positive exponential waveform within the leading edge portion of the reflected signal; determining the length of the lossy electrical cable based on the time of flight.