In one embodiment, a system may be provided that includes a circuit that is electrically coupled to a line. The circuit generates a direct current signal on the line, where the direct current signal has a period that includes a charge cycle and a discharge cycle. The circuit charges the line in the charge...http://www.google.fr/patents/US8058750?utm_source=gb-gplus-shareBrevet US8058750 - Discharge cycle communication
