New method for analyzing the quality of a telephone network

The development of new broadband services over the telephone network requires a good quality of the installation. An important parameter that verifies the quality of a telephone installation system is the symmetry of the line. A measure of the symmetry, made from the telephone exchange center, does not allow remote observation of asymmetry on the client telephone installation. To address this problem, a new method for analyzing the quality of the pair is proposed in this paper. This method consists of evaluating the symmetry of the line by a LF (low frequency) measure made from the telephone exchange side. The aim of this study is to verify the feasibility and the validity of this technique, by a theoretical approach. We have developed a simulation code based on the theory of multi-wire transmission lines, associated with a topological approach. The model and the code are validated using experimental measurements. In the following, we exploit the simulation tool to evaluate this new measurement technique. A second axis of the study was to search for a correlation between the values of LF symmetry evaluated from the telephone exchange side and the values of HF symmetry evaluated at client side.