In the Star Wars movie Rogue One, we see the Rebels communicating over the radio whilst at Light-speed. I don't recall seeing this in other Star Wars movies. (They pop out of Hyperdrive - and the situation is a big surprise).
Generally the idea of Hyperspace (note that we're making a distinction between Hyperdrive in Star Wars, and Warp Drive in Star Trek) is that you're in other dimension and can't communicate. Speaking generally - we do see a Star Trek movie make a big deal of being able to beam someone onto a ship travelling at Warp.
To me it seems that communicating over the radio at Hyperspace affects the plot (ie a Plot Hole) of some of the other Star Wars movies.
LANDO Don't worry, my friends are down there. They'll have that shield down on time... (to himself) or this'll be the shortest offensive of all time.
The copilot flips some switches and grunts an alien comment.
ACKBAR (VO) All craft, prepare to jump to hyperspace on my mark.
92 EXT SPACE - ENDOR, DEATH STAR, REBEL FLEET
The Death Star and its Sanctuary Moon hang distant in space as the Rebel fleet comes out of hyperspace with an awesome roar. The Millennium Falcon and several Rebel fighters are at the front as the space armada bears down on its target.
LANDO Break off the attack! The shield is still up.
RED LEADER (VO) I get no reading. Are you sure?
LANDO Pull up! All craft pull up!
The Falcon turns hard to the left. Out the window the stars and the Death Star move off right.
Now if Hyperspace radio existed - they wouldn't need to plan to 'hope' they've opened the shield - they could just radio back and tell them.
My question is: Does Rogue One create a plot hole in Return of the Jedi re Hyperspace Radio?