The paper deals with the possibility of using the distribution line carrier (DLC) in order to prevent dispersed generation islanding. The feasibility of this technology applied to MV networks has been investigated from a theoretical as well as experimental point of view. A multiconductor matrix procedure based on bus admittance matrix allows us to predict the high frequency behaviour of MV lines (overhead and cable): the signal strength can be verified at any section of MV networks. Moreover two measurement campaigns have been performed on real MV networks in order to validate the theoretical results.