A two step hybrid method for loop topology estimation of two wire and Power Lines

Physical Power Lines have the capacity to distribute broadband within residential premises. A two-step (hybrid) procedure to extract open port physical line topology, that can be used to simulate channel models is discussed here. An initial approximate estimate of the loop is obtained from Frequency Domain Reflectometry (FDR) measured data itself, or by a Correlation Time Domain Reflectometry (CTDR). Thereafter an optimization algorithm is used to predict a more accurate loop topology, by iterating with an objective function based on the measured FDR data, and the computed frequency domain echo of the initial estimate. Verification of this optimization scheme was done by actual FDR measurements on physical loops. Additionally introduced is a Genetic Algorithm (GA) procedure to verify from the measured FDR data for plain lines. Simulations are presented for a typical physical power lines using a hybrid of CTDR and FDR methods. The advantages of the proposed method are; the measurement is done by reusing most of the firmware modules in a typical DSL modem and with no prior knowledge of line topology.