radiotelegraphy vs radiotelephone

radiotelegraphy

noun
  • The process and techniques of sending telegrams using radio waves rather than wires. 

radiotelephone

noun
  • a device that allows two-way communication via radio 

verb
  • To communicate via such a device 

How often have the words radiotelegraphy and radiotelephone occurred in a corpus of books? (source: Google Ngram Viewer )