Interstellar Communication

Communication within the Highlands, and among some of the more advance Midland communities is very much based upon the existence of the hypercable communication system which is strung along the Major Routes. Worlds located in systems within transmission distance of the subspace gates or anchored hypercable relay stations have effectively instant communication with every other world on a major route.
Subspace gates provide the conduit between the hypercable system in subspace and standard transmission in real space. Most gates are either in stellar or planetary orbit. For those in stellar orbit there would often be a noticeable lag, as gates not placed in stabilized subspace must be at least 100 solar and planetary diameters away from these bodies.
So for example in the Solar System a gate would have to be located in an orbit at least 70 million miles beyond the sun. Since the minimum distance a gate would have to be from Earth would be at least 791,000 miles it could not be placed in a standard orbit, it would most likely be placed in one of the Lagrange points which are far enough to be outside the 100 diameter limits, yet close enough to ensure both minimum transit time to Earth and minimum time lag for communication carried on electromagnetic waves (radio).
Of course the gate orbiting Earth is in stabilized subspace. A hyperdrill has been used to provide a subspace conduit that allows the gate to be place within the normally exclusive 100 diameter zone. This allows  the Earth gate to be located in a geostationary orbit at approximately 22,236 miles above the equatorial Pacific Phoenix Islands.
Of course this creates another problem, which is the delay caused by the distance between Earth and the colonies in the Trans-Jupiter and farside asteroid belt.
Under normal circumstances a message transmitted from the communication array at EarthGate could require almost a hour to reach one of the moon stations at Jupiter
This problem is addressed through the use of hypercable boundary relays. A hypercable boundary relay is an unmanned station about the size of an old style bus which is place by a hyperdrill. It is place at the boundary of subspace with its body anchored to the subspace plane by a gravity anchor. Within the relay a microgate allows a transmission antenna to extend into real space. This antenna would be located within a suitable distance of Jupiter, orbiting with the planet.
So to send a message from Earth to Ganymede Base the message would be routed not to EarthGate's real space EM array, but rather through the hypercable relays already placed along the Major Route in subspace. From there it would be sent to the boundary relay, where it would then be transmitted to real space in the general vicinity of Jupiter. This results in not just effectively instant communication from Earth, but instant communication from anywhere in the Highlands.
Since for all intents and purposes everything is data the hypercable system provides the backbone for a Highland wide network of connected devices. Citizens of the Union use this network for everything from communication to entertainment. It also provides a vast repository of knowledge which is available to any world connected to the system.
But of course even in the Highlands there are many worlds not connected to the system. Worlds along Blue Highways are not hooked into the hypercable system, though it is quite possible local system wide relays might exists.
Typically worlds along Blue Highways have local networks which receive recorded data from the closest hypercable node, delivered by the Grand Postal Service. Most such systems do not have boundary relays so interplanetary communication is often plagued by time lags that make email a better communication medium than video calls. Interstellar communication is primarily via text or recorded message.
Because the network of the Major Routes do not consist of a regular pattern, but are distributed based upon world location, population, and other economic factors how a message is routed can have a significant effect on the time involved in delivering it. The Grand Postal Service spends a lot of resources determining the routes which will result in the fastest delivery of message sent to disconnected worlds.
This disjointed system often results in news being delivered almost or more rapidly by private or commercial vessels before official news organizations. Both Church and government maintain couriers in an attempt to stay ahead of rumor or even official news.