Double-ended line probing (DELP) for DSL systems
AssigneeIkanos Communications, Inc.
InventorsNima Ferdosi, Jalil Kamali
Life of this patent
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Abstract
Double-ended line probing (DELP) techniques are described herein that enable a loop configuration to be identified based on mathematically simple error functions, which are both time-efficient and less sensitive to measurement errors. A DELP algorithm uses readily available data about the channel that is generated prior to the modem operation (e.g., theoretical loop models) and other available data (e.g., that provided by loop diagnostic modules) to estimate the loop configuration including the line length and gauge, as well as the number of bridge taps and their gauges, lengths, and locations.
Claims18
A method for double-ended line probing (DELP) on a copper telephone line having up to two bridge taps located thereon, comprising:
- measuring an overall channel insertion loss magnitude on the copper telephone line;
- generating a bridge tap error function #1 which includes the measured channel insertion loss magnitude measured in the measuring act and estimated insertion loss magnitudes of the bridge taps for all possible bridge tap gauges and lengths;
- estimating a gauge and length for each bridge tap that minimizes the bridge tap error function #1 generated in the generating act;
- deriving the insertion loss for the line with no bridge taps by dividing the overall channel insertion loss measured in the measuring act by a product of insertion loss magnitudes associated with the estimated bridge tap length and gauge estimated in the estimating act;
- and
- estimating a first approximation of a length and gauge for the line based on the insertion loss of the line with no bridge taps derived in the deriving act;
- thereby transforming the measured overall channel insertion, loss magnitude into physical and topological parameters of the copper telephone line, including both the estimated length and gauge of the telephone line together with estimated bridge tap length and gauge thereof.
A means for double-ended line probing (DELP) on a copper telephone line having up to two bridge taps located thereon, comprising:
- means for measuring an overall channel insertion loss magnitude on the copper telephone line;
- means for generating a bridge tap error function #1 which includes the measured channel insertion loss magnitude measured by the means for measuring and estimated insertion loss magnitudes of the bridge taps for all possible bridge tap gauges and lengths;
- means for estimating a gauge and length for each bridge tap that minimizes the bridge tap error function #1 generated by the means for generating;
- means for deriving the insertion loss for the line with no bridge taps by dividing the overall channel insertion loss measured by the means for measuring by a product of insertion loss magnitudes associated with the estimated bridge tap length and gauge estimated by the means for estimating;
- and
- means for estimating a first approximation of a length and gauge for the line based on the insertion loss of the line with no bridge taps derived by the means for deriving;
- thereby transforming the measured overall channel insertion loss magnitude into physical and topological parameters of the copper telephone line, including both the estimated length and gauge of the telephone line together with estimated bridge tap length and gauge thereof.
Dependencies are inferred from the claim text.