Since the invention of radio, Earth has been broadcasting signals out into the universe. The very first signals were extremely basic. AM basically takes vibration and slaps a carrier wave on it. Over time, signals got more complicated, but if you understood how the first signals worked, you could probably guess what changes happened to create the new format. An alien wanting to communicate with earthlings could probably go and sample everything Earth has broadcast over the decades and learn how that new and improved protocol works.
Or comms with a new civilization could start with some exchange of voyager-style basic info about the species, then negotiate an AM signal, then use that to negotiate a more complex signal, until you build up a complex and data-dense signal that both ships are able to encode and decode.
Also, a lot of the complexity of modern signals comes from compression and encryption. Compression because you want to get as much signal as possible through a crowded transmission medium. Encryption because you don’t want unauthorized people to access the data. In a ship-to-ship encounter in space you might not need to worry about those two things. You can use immense bandwidth because there’s nobody else using that section of space so there’s no need to restrict your transmission, and you want to communicate so you’ll remove all the encryption that would prevent that.
I’m imagining two super-competent AI speaking to each other like - “Here’s three terabytes of our home planet history in annotated pictures, it covers the period since my people first crawled out of the sea, and yea that’s why we are using base-14 numerical system, just count the number of the tail spikes. Okay, in three milliseconds the captain will press the communication button, just draw this picture stream however you like, it doesn’t matter if you draw left-to-right or right-to-left, you are aliens anyway so you won’t tell one fish face from another, and your species see in different color range, so just swap the colors to look fancier, our skin will look to you dull grey in person.”
Since the invention of radio, Earth has been broadcasting signals out into the universe. The very first signals were extremely basic. AM basically takes vibration and slaps a carrier wave on it. Over time, signals got more complicated, but if you understood how the first signals worked, you could probably guess what changes happened to create the new format. An alien wanting to communicate with earthlings could probably go and sample everything Earth has broadcast over the decades and learn how that new and improved protocol works.
Or comms with a new civilization could start with some exchange of voyager-style basic info about the species, then negotiate an AM signal, then use that to negotiate a more complex signal, until you build up a complex and data-dense signal that both ships are able to encode and decode.
Also, a lot of the complexity of modern signals comes from compression and encryption. Compression because you want to get as much signal as possible through a crowded transmission medium. Encryption because you don’t want unauthorized people to access the data. In a ship-to-ship encounter in space you might not need to worry about those two things. You can use immense bandwidth because there’s nobody else using that section of space so there’s no need to restrict your transmission, and you want to communicate so you’ll remove all the encryption that would prevent that.
I’m imagining two super-competent AI speaking to each other like - “Here’s three terabytes of our home planet history in annotated pictures, it covers the period since my people first crawled out of the sea, and yea that’s why we are using base-14 numerical system, just count the number of the tail spikes. Okay, in three milliseconds the captain will press the communication button, just draw this picture stream however you like, it doesn’t matter if you draw left-to-right or right-to-left, you are aliens anyway so you won’t tell one fish face from another, and your species see in different color range, so just swap the colors to look fancier, our skin will look to you dull grey in person.”