Communication is one of the central pieces in science fiction. It can define how fast the information propagates. The control of it also defines who is in power. And that's pretty much true in the real world as well.
The predictions made decades ago are starting to become reality. Wireless ubigous communication is here, has been many years already. We can transfer information at the speed of light all around the globe.
But the speed haven't really increased over the years. Our ancestors were already able to communicate at the same speed thousands of years ago using things fire beacons, semaphores or smoke signals. The reach has just become better. So far, it has been enough. There isn't any notable delay in real time communications between any point on earth. But as soon as we leave this planet things get interesting. The delay just between the closest celestial body is already 2,5 seconds. And in stellar scale that's practically nothing.
There is a lot of solutions for this problem presented in sci-fi: hyperspace, wormholes, quantum entanglement or tachyons have all been used to transfer information faster than traditional physics would allow. But despite thousands of years of progress in science, we are still bound to that limit.