A two-step (hybrid) procedure to extract open port physical line topology 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 defining an objective function and iterating based on the measured FDR data, and the computed frequency domain echo of the initial estimate. Verification for this optimization scheme was done by actual FDR measurement Tests on physical loops. Additionally introduced is a Genetic Algorithm (GA) procedure to verify the measurement data for plain lines. Simulations are presented for a typical physical power lines using the hybrid method. No prior knowledge of the network topology is required.
Index Terms -Digital subscriber line (DSL), Power Line Communication (PLC), Frequency domain Reflectometry (FDR), Correlation time domain Reflectometry (CTDR), Loop qualification.