Foo Fighters - Over and Out Lyrics Meaning

I think the song is about Dave's personal relationship with someone he knew before reaching stardom (first to reach the stars wins a broken heart). At this point, his only way of reaching her is through song, more specifically the radio. Hence the name Over and Out, obviously serving as a double entendree because the state of the relationship is in the same position. The song is his last attempt to make any contact with her. He is using it in the same way someone would use a walkie-talkie to try to make contact with someone.