Sender and receiver should get together. The separation between transmitter and receiver is mere a political operation. Technologically, there is no separation in them. Message' is also problematic. Media don't transport message but do refer here to there.
Airwaves relate to casting and resonating.
As a casting medium, airwaves spread information upon the audience. As a resonating medium, however, airwaves create various enclaves of emotions in the audience. The Internet and cable media depend on lines. Lines relate to binding, weaving, and streaming. However, lines are not always tight but loose.