Single ended line probing in DSL system using combined FDR-TDR approach
OwnerJalil Kamali, Farrokh Rashid-Farrokhi +1inventors
InventorsJalil Kamali, Farrokh Rashid-Farrokhi, Guozhu Long
Life of this patent
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Abstract
A Single Ended Line Probing (SELP) technique using combined Frequency Domain Reflectometry (FDR) and Time Domain Reflectometry (TDR) for characterizing a transmission medium (e.g., DSL) is disclosed. FDR is used to detect one or more reflectors (e.g., short, load coil, bridge tap) in the transmission medium. TDR is then used to determine the location of the reflectors in the transmission medium. In one embodiment, a wide band periodic probing signal is used to probe the transmission medium for reflectors. In another embodiment, gauge information can be used to increase the valid range of the combined FDR/TDR SELP technique.
Claims13
A method of estimating a length of a transmission medium using Single Ended Line Probing (SELP), the method comprising the steps of:
- probing the transmission medium with a probe signal;
- receiving a reflected version of the probe signal;
- determining if a reflector is present in the transmission medium using Frequency Domain Reflectometry (FDR);
- and responsive to a determination that a reflector is present in the transmission medium,
- determining the location of the reflector in the transmission medium using Time Domain Reflectometry (TDR).
A system for estimating a length of a transmission medium using Single Ended Line Probing (SELP), the system comprising:
- a transmitter adapted to be coupled to the transmission medium for probing the transmission medium with a probe signal;
- a processor coupled to the transmitter and adapted for processing a reflected version of the probe signal to determine if a reflector is coupled to the transmission medium using Frequency Domain Reflectometry (FDR);
- and responsive to a determination that a reflector is present in the transmission medium, using Time Domain Reflectometry (TDR) to determine the location of the reflector in the transmission medium.
A computer-readable medium having instructions contained thereon, which, when executed by a processor in a Single Ended Line Probing (SELP) device, perform the operations of:
- configuring a transmitter in the SELP device to probe a transmission medium with a probe signal and process a reflected version of the probe signal to determine if a reflector is present in the transmission medium using Frequency Domain Reflectometry (FDR);
- and responsive to a determination that a reflector is present in the transmission medium, using Time Domain Reflectometry (TDR) to determine the location of the reflector in the transmission medium.
A system for estimating the length of a transmission medium using Single Ended Line Probing (SELP), comprising:
- means for probing the transmission medium with a probe signal;
- means for receiving a reflected version of the probe signal;
- means for determining if a reflector is present in the transmission medium using Frequency Domain Reflectometry (FDR);
- and responsive to a determination that a reflector is present in the transmission medium,
- means for determining the location of the reflector in the transmission medium using Time Domain Reflectometry (TDR).
A processor for use in a Digital Subscriber Line (DSL) modem, comprising:
- memory adapted for storing computer program code, the computer program code including instructions for processing a reflected version of a probe signal received from a transmission medium to determine if a reflector is present in the transmission medium using Frequency Domain Reflectometry (FDR), and responsive to a determination that a reflector is present in the transmission medium, using Time Domain Reflectometry (TDR) to determine the location of the reflector in the transmission medium;
- and
- circuitry for executing the computer program code.
Dependencies are inferred from the claim text.