A system includes a first communication module to be coupled to a first transmission medium for distributing power using a voltage waveform having a first amplitude; and a second communication module to be coupled to a second transmission medium for distributing power using a voltage waveform having a second amplitude different from the first amplitude, the second transmission medium being coupled to the first transmission medium. Each of the first and second communication modules is configured to use signals that propagate between the first and second transmission media.