# US 7,613,236 B2 · Transmit power adjustment based on estimated electrical length of a loop > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,613,236 B2 - Document ID: US7613236B2 - Status: Granted - Kind: B2 - Application number: 11/430,775 - Filed: 2006-05-09 - Published: 2006-09-14 - Granted: 2009-11-03 - Earliest claimed: 2002-07-23 - Assignees: Broadcom Corporation - Inventors: Vladimir Oksman; Raphael Rahamim - Web page: https://patentgrep.com/patent/US7613236B2 ## CPC - H04L 12/66: Arrangements for connecting between networks having differing types of switching systems, e.g. gateways - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method for estimating electrical length of a loop in a digital subscriber line (DSL) system begins by estimating an electrical length of a loop for each of a plurality signals based on a known power level of the plurality of signals, a known frequency for each of the plurality of signals, and a received power level for each of the plurality of signals. The method continues by processing the plurality of estimated electrical lengths in accordance with a function corresponding to characteristics of the loop to produce a determined electrical length. ## Claims ### Claim 1 A method for estimating electrical length of a loop in a digital subscriber line (DSL) system, the method comprises: estimating an electrical length of the loop for each of a plurality of signals based on a known power level of the plurality of signals, a known frequency for each of the plurality of signals, and a received power level for each of the plurality of signals; and selecting one of the plurality of estimated electrical lengths having a smallest value to produce a determined electrical length of the loop. ### Claim 2 (depends on 1) The method of claim 1, wherein the estimating the electrical length of the loop for each of the plurality of signals comprises: receiving the plurality of signals, wherein each signal of the plurality of signals is transmitted at the known power level; and determining the received power level for each signal of the plurality of signals as the signal is received. ### Claim 3 (depends on 1) The method of claim 1, wherein the estimating the electrical length of the loop for a signal of the plurality of signals comprises: determining an attenuation factor based on the known power level and the received power level of the signal; and dividing the attenuation factor by a reference attenuation value to produce a corresponding one of the plurality of estimated electrical lengths, wherein the reference attenuation value is obtained by taking a square root of the frequency of the signal, by taking the square root of the frequency of the signal and adding a first coefficient thereto, or by taking the square root of the frequency of the signal and adding a first coefficient thereto and adding a product of the frequency of the signal and a second coefficient. ### Claim 4 An apparatus for estimating electrical length of a loop in a digital subscriber line (DSL) system, the apparatus comprises: means for estimating an electrical length of the loop for each of a plurality of signals based on a known power level of the plurality of signals, a known frequency for each of the plurality of signals, and a received power level for each of the plurality of signals; and means for selecting one of the plurality of estimated electrical lengths having a smallest value to produce a determined electrical length of the loop. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the means for estimating the electrical length of the loop for each of the plurality of signals functions to: receive the plurality of signals, wherein each signal of the plurality of signals is transmitted at the known power level; and determine the received power level for each signal of the plurality of signals as the signal is received. ### Claim 6 (depends on 4) The apparatus of claim 4, wherein the means for estimating the electrical length of the loop for a signal of the plurality of signals functions to: determine an attenuation factor based on the known power level and the received power level of the signal; perform a square root function of the known frequency for the signal to produce a frequency value; and divide the attenuation factor by the frequency value to produce a corresponding one of the plurality of estimated electrical lengths. ### Claim 7 A method for estimating electrical length of a loop in a digital subscriber line (DSL) system, the method comprises: estimating an electrical length of the loop for each of a plurality of signals based on a known power level of the plurality of signals, a known frequency for each of the plurality of signals, and a received power level for each of the plurality of signals; weighting each of the plurality of estimated electrical lengths to produce a plurality of weighted estimated electrical lengths; and computing a determined electrical length of the loop as a function of the plurality of weighted estimated electrical lengths. ### Claim 8 (depends on 7) The method of claim 7, wherein the estimating the electrical length of the loop for each of a plurality signals comprises: receiving the plurality of signals, wherein each signal of the plurality of signals is transmitted at the known power level; and determining the received power level for each signal of the plurality of signals as the signal is received. ### Claim 9 (depends on 7) The method of claim 7, wherein the estimating the electrical length of the loop for a signal of the plurality of signals comprises: determining an attenuation factor based on the known power level and the received power level of the signal; and dividing the attenuation factor by a reference attenuation value to produce a corresponding one of the plurality of estimated electrical lengths, wherein the reference attenuation value is obtained by taking a square root of the frequency of the signal, by taking the square root of the frequency of the signal and adding a first coefficient thereto, or by taking the square root of the frequency of the signal and adding a first coefficient thereto and adding a product of the frequency of the signal and a second coefficient. ### Claim 10 (depends on 7) The method of claim 7, wherein the weighting each of the plurality of estimated electrical lengths comprises: determining for each of the plurality of estimated electrical lengths a weighting factor that is proportional to an inverse of a magnitude of the estimated electrical length; and weighting each of the plurality of estimated electrical lengths by their respective weighting factor. ### Claim 11 (depends on 7) The method of claim 7, wherein computing the determined electrical length comprises: computing at least one of an average, a root mean square, and a least mean square of the plurality of weighted estimated electrical lengths. ### Claim 12 (depends on 11) The method of claim 11, wherein each of the plurality of estimated electrical lengths are weighted such that smaller valued ones of the plurality of estimated electrical lengths have a greater weighting factor than larger valued ones of the plurality of estimated electrical lengths. ### Claim 13 An apparatus for estimating electrical length of a loop in a digital subscriber line (DSL) system, the apparatus comprises: means for estimating an electrical length of the loop for each of a plurality of signals based on a known power level of the plurality of signals, a known frequency for each of the plurality of signals, and a received power level for each of the plurality of signals; and means for weighting each of the plurality of estimated electrical lengths to produce a plurality of weighted estimated electrical lengths; and means for computing a determined electrical length of the loop as a function of the plurality of weighted estimated electrical lengths. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the means for estimating the electrical length of the loop for each of the plurality signals functions to: receive the plurality of signals, wherein each signal of the plurality of signals is transmitted at the known power level; and determine the received power level for each signal of the plurality of signals as the signal is received. ### Claim 15 (depends on 13) The apparatus of claim 13, wherein the means for estimating the electrical length of the loop for a signal of the plurality of signals functions to: determine an attenuation factor based on the known power level and the received power level of the signal; perform a square root function of the known frequency for the signal to produce a frequency value; and divide the attenuation factor by the frequency value to produce a corresponding one of the plurality of estimated electrical lengths. ### Claim 16 (depends on 13) The apparatus of claim 13, wherein the means for weighting each of the plurality of estimated electrical lengths functions to: determine for each of the plurality of estimated electrical lengths a weighting factor that is proportional to an inverse of a magnitude of the estimated electrical length; and weight each of the plurality of estimated electrical lengths by their respective weighting factor. ### Claim 17 (depends on 13) The apparatus of claim 13, wherein the means for computing the determined electrical length functions to: compute at least one of an average, a root mean square, and a least mean square of the plurality of weighted estimated electrical lengths. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein each of the plurality of estimated electrical lengths are weighted such that smaller valued ones of the plurality of estimated electrical lengths have a greater weighting factor than larger valued ones of the plurality of estimated electrical lengths.