When we think to interstellar communications, we immediately think to radio signals with medium or large antennas :

* We all know about radio signals in [seti](https://fr.wikipedia.org/wiki/Search_for_Extra-Terrestrial_Intelligence).
* In the case of fictional stories, some peoples will even rememberer the broken antenna of Obi‑Wan in Star Wars episode 2 where he finally manage to contact coruscant half of the galaxy away *(through radio signals)*.

However, we know the drawbacks :

* the farther the target is, the more the required energy is. This start to heart our space exploration : for example, we disable many instruments on voyager probes only for few extra energy saving whereas the antenna consume more than all combined instruments.
* transfer speeds happen at speed of light : this may sound fast but at the galaxy level, things can take centuries in order to travel. Everyone know the case of the philæ probe that landed at 90° angle because as it happened in automatic mode, gyroscopic stabilizers being stopped on the first touch *(not to mention the rosetta relay requirement that prevented the primary mission objective to complete)*.

So at some point, the use of radio signals become a strong STOP *(definitely aborting the idea to send data between galaxies and well shorter before that)*. 

In the same time, there are reports of communication using quantum nonlocality over short distances *(this might only solve the energy problem, speed being only one among others)*.  

Of course I read about the theoretical possibility of quantum nonlocality in use in communications before asking this question : that’s why I think [surveys like this one](http://science.sciencemag.org/content/early/2014/05/28/science.1253512) are hoax.