A system that permits use of existing cable TV wiring for home networking is disclosed. Because of the presence of splitters, notch filters, and other components in the cable distribution system, certain of the premises installations in the system can locally communicate over the same frequency as one another, without interference. In a disclosed embodiment, the cable operator determines the attenuation and isolation among different premises in the system, and then assigns home network frequencies to the particular premises, with those premises installations that are sufficiently isolated from one another being assigned the same home network frequency.