cable television vs transmission line

cable television

noun
  • Television received through coaxial cables; specifically, a TV service that provides reception to suburbs or other residential areas through utility lines and offering a wide variety of TV channels through satellite reception. 

transmission line

noun
  • A set of wires used for long-distance electric power transmission; a power transmission line. 

  • A structure such as a waveguide or stripline constructed so as to pass electric signals with fidelity and little loss. 

How often have the words cable television and transmission line occurred in a corpus of books? (source: Google Ngram Viewer )