If you like hard sci-fi, the amazing trilogy by Liu Cixin The Three Body Problem uses gravitational wave communication as an important part of the plot.
Long membrane communication.
Such a great chapter. It amazes me how the author can take a huge step back and get into the mind of this curious character
Is it possible that alien civilizations are using gravitational waves to communicate? Maybe that's why we've literally had "radio silence" so far.
Exactly what I was thinking, given we are beginning to go dark (in terms of radio transmission) as well, perhaps SETI are looking at the wrong type of information transmission to detect our neighbours. A hypothetical alien civilization could be using an entirely different type of technology to transmit information to what we have previously assumed, maybe gravity waves maybe something else, that we haven't even thought of yet.