Inspired from this question, do FTL communications exist in the Aliens franchise/universe?
FTL communications certainly exists with the 'Aliens' universe. On at least one occasion we see a colony (in this case the former mining colony depicted in Alien³) "phoning home". Just seconds later they receive a written response.
The novelisation explains it as a function of subspace. Apparently it's ferociously expensive, to the point that the colony has never received a realtime communication in its entire history.
Andrews sat back in his chair, his eyes cutting into his guest. "At 0700 hours I received a reply to my report from the Network. I may point out that to the best of my knowledge this is the first high-level, priority communication this installation has ever received. Even when Fiorina was a working, functioning mining and refining operation it was never so honored. You know why?"
Clemens sipped his tea. "High-level priority communications have to go through subspace to beat the time problem. That costs plenty."
Andrews was nodding. "More than you or I’ll ever see."
There's another example of FLT communication in Aliens. We learn that after Ripley's testimony The Company (and more specifically Carter Burke) sent a communique to Hadley's Hope telling them the approximate location of the downed Space Jockey ship and asking them to go take a look.
A deleted scene also mentions that at their distance, it usually takes 2 weeks to get a cursory response. This lends weight to the idea that there are two sets of FTL communications; realtime subspace, and low priority comms (presumably carried on ships traveling between star systems).
In the schematic offered in the "Alien Vault" factbook, we learn that the Nostromo also has a subspace communications antenna for interstellar communications.