Communications
The very first dedicated FTL communications systems of most powers were simply automated FTL buoys (most often warp-drive or hyperdrive for many powers). The buoys would be dispatched, either on command or a regular basis, between systems. This was both expensive and quite readily able to be interrupted.For those powers that had developed hyperdrive, experimentation often proceeded with attempts to send pulses in hyperspace (or at least along the hyper-stratum with later understanding). These experiments sometimes succeeded, and sometimes did not (the Royal Elven Kingdoms managed a workable system, Earth-N did not), but they were little if any faster than a starship courier and required a disproportionate amount of energy.
Ultimately, it was the quantum entanglement which eventually provided the impetus for true, long-range FTL communications. The science of quantum entanglement itself, let alone the more advanced sciences that spun off it, is a heavy topic to broach, but the simple explanation is that if you do something to one particle of an quantum entangled pair, the other shows the same effect, even if they are separated widely by distance. With a series of these, you can use this to transmit data.Quantum entanglement itself became something of a dead-end technology. As it relies on pairs of particles, on at each end of the communication, it limits the system to between the two fixed points. In order to have a communications network, the number of pairs for each separate node quickly snowballs. For a typically a century or so, such systems lingered for critical communications links between the governors of planets, but eventually, they were superseded.But the idea persisted. Between the knowledge of other-dimensional spaces like hyperspace and subspace and teleportation (powers with access to magic had a greater head start here), could there be a way to use those spaces to, essentially instantly transmit data from one point to another?The answer was yes. It was answered in a myriad of ways, by various powers. Indeed, modern communications systems are not a single device, but a plethora of various transmitter and receiver devices in them, acting in concert. However, all these devices have more or less the same convergent properties (there are only so many ways of doing things, after all), which means it is very rare for even unknown species not to be able to interact on at some level.The single largest feature most FTL communications systems have in common is that they are all, fundamentally, still point-to-point, going directly between the nodes of the communication units. The speed of this communication is effectively instantaneous. However, the terminology still refers to "transmitting" and "receiving," since the time in which the data travels is not actually instantaneous, and there is measurable travel time. The differences are so small, however, that to get true lag, distances would be in tens of thousands of light years – far beyond the range of the current communications systems.Furthermore, unlike theoretical perfect quantum entanglement systems, however, the range at which a communication system can do so is limited. While a larger array can connect to a node further away, there is a limiting factor of technology how large an array can become. (Especially so on a starship.) To once again re-visit and inaccurate-but-illustrative example, like an arc of electricity jumping between two points – too much distance and the arc cannot leap across the inherent resistance of the air; in this case, the communications signal is the arc, and the "air" the underlying fabric of the universe (and/or the other-space the signal is sent along).A full-spectrum broadcast, like an unshielded civilian transmission or a distress beacon may be thought of as arcing simultaneously to all nodes within range. (These signals are so-called because it will transmit across all of the pertinent devices in all directions.) A transmission that is more directed (such as between warships) would be between specifically selected nodes.The range can be increased by transmitting the signal through another node, however, making the true transmission range only limited by the extent of the node network. The un-augmented range of a modern communication is still significant. Even ancillary systems like helmet or scanner communications can reach distance of AU by themselves, and hand-held communicators can reach a few light-years, even without a starship or satellite from which to "bounce" the signal further. The difference in range due to size is also disproportionately greater, with larger systems having considerably better ranges. Dedicated long-range communications gear has even greater ranges, but these are usually only found on fixed installations or stations or on specialised fleet command and communications ships. I.e. specialist support vessels above and beyond normal, smaller communications vessels.
For example, in the Aotrs fleet, the Traitor Recon Destroyer serves as the communications vessel for task forces and detected fleet elements. But for an entire fleet (e.g. the Aotrs 1st or 2nd Fleet, which have hundreds of vessels including ancillary and support ships) there may be usually only one or two long-range communications vessels in the entire fleet. These specialist support vessels are not typically combat vessels at all, like the repair and refuelling vessels they accompany. (In the specific case of the Aotrs, such vessels are typically refits of large capital ships, often of prior generations, or aboard the few supercruisers, instead of a dedicated ship design.)This is further complicated by the fact that an active communication system, actively transmitting or not, acts as a dimple of lower "resistance" inherently – as it must to be able to receive any signals at all. Thus, if you are reasonably familiar with, and have at least technological parity with a power's communication system, you can "bounce" your own communications through these points of low resistance and further extend your range without actually interacting with their node directly at all. This somewhat reduces the range you can jump between nodes, however, proportionally to how "close" you come to actually connecting to their node (and thus them getting your transmission directly).This capability is limited to military-grade systems (legal or otherwise), though some very high technological civilian technology bases can do it if they are superior.
As an illustrative example of communications limitations in action, we can look back the incident transcribed in the postscript of the Guide to the Aotrs. To recap, Damning Echo Base is a facility located by the Aotrs Myst Exploratory Teams through the Myst Gate, which lies significantly across the galaxy. Damning Echo Base is sufficiently far from Aotrs space that direct communications to it are only possible once relayed through Myst Base with the Myst Gate open. (This is the case with the majority of the AMET expeditions.)
At the time of the incident, the new Echo defence fleet had not even arrived at the facility; it was at least three weeks away from Damning Echo and already well out of Aotrs space. However, Lord Death Despoil was able to contact Echo fleet and immediately issue orders.This was possible because Lord Death Despoil was on Fearmore, which as the capital world has significant communications facilities of its own. However, Admiral Fellbane's fleet also would have specialised long-range communications gear on the fleet command vessels – the sort of vessels which do not typically sit in the main battle line, but remain with transport units in the rear deployment of a combat zone. Echo fleet was also transporting more such equipment to set up at the base, specifically to be able to communicate with the far-distant Aotrs space. This equipment was of sufficient size that it could not be transported through the Myst Gate, which was why Damning Echo was still reliant on the Myst Gate for communications.
So, on the one hand, modern communications have only a limited (but large) range to which they can transmit or receive from another unit; on the other, if the unit is in range of the transmitter, there is no perceivable lag. The effects of enemy ECM, spatial anomalies and other phenomena can have an effect on signal clarity, communications range and even signal lag, but these are rare exceptions to the rule.
It is rare, then, for a star system to entirely lose communications altogether. The nightmarish scenarios of colonies lost for centuries when they dropped off the grid has thus failed to materialise, because the modern grids are so dispersed as to be indestructible on a practical level (unless the colony itself is completely levelled). However, this can occasionally happen in specific circumstances.The fall of the Strayvian Empire caused such a black-put to occur in their former territories. This was in part, however, due to the Strayvian's own control-freak tendencies, where they had made a spirited effort for control the flow of information through their own communications arrays. They could achieve this due to their technological superiority at the time. These arrays were all destroyed during the various rebellions, as they were all, ultimately, military facilities used by the occupation. The surviving powers did not build replacements, or if they did, with but a fraction of the strength. And so the region remained a black box until the modern era, which meant that humanity had no prior warning of the Strayvian's sudden re-appearance a hundred and fifty years later.It is thus possible to see how a species that did not discover FTL communications technology could fall prey to such incidents. Given the variability of the ease at which one can break through into other-space, it is possible a power in a fairly difficult region might not find access to the means required. (This is one suggestion as to why the elenthnars did not discover hyperdrive first.) So there may indeed be unknown empires out in the galaxy which still have to rely on STL communications methods.Intercepting Communications
Actually intercepting communications (as to be able to read their contents) is quite difficult with FTL communications gear. As such transmissions are, by nature point-to-point, they leave no trace when not active. Unlike slower-than-light transmissions which can spend centuries crossing the void of space, in order to be able to intercept an FTL communications system, the interceptor needs to be within sensor range of the communicators to be even able to see them. This usually means navigational sensors [a few to a few tens of lightyears, dependant on the size and technology of the sensors], since while possible with active sensors, the chances of catching FTL communications in the much smaller bubble are drastically lower.The sensors also need to be sufficiently advanced to be able to detect the transmissions. Finally, even if the transmission can be detected and read, there are the problems of breaking encryption and translation.
While "universal" translators exist (and does translation magic), these generally are only helpful for extrapolating from all known languages and/or are geared specifically towards the humanoid (and elenthnaroid) brain. Extremely esoteric or alien languages are beyond their capabilities. Notable examples of languages are extremely difficult or near-impossible to translate even by linguistic specialists (with dedicated computers and/or magic) are the Harbinger, the Stone Portal and Grey Watcher In The Mire (i.e. Rift Collective) languages, as is the encoding of a Cybertank's brain.In the earliest days of space-travel, sensor arrays focussed to looking outside of a system had to rely on passive systems like space telescopes, or like Earth's SETI program, hoping to catch stray alien STL transmissions. As technology advanced, the early FTL phase saw these sorts of programs have their golden age, with large arrays of navigational sensors, looking towards other parts of space in the hopes of likewise catching information.However, in generally, FTL transit is much more readily visible than FTL communications, and it is thus always a far better indicator of the presence of an unknown power. (That said, absence of evidence is not evidence of absence – not detecting any FTL signatures in a region just might mean that it is too advanced for your sensors.)In the modern era, then, such sensor arrays are back to the prominence of their origins. As the civilisations of the galaxy have expanded, so the reach of fixed installations has relatively shrunk, since they cannot now look past their neighbours. The programs still exist in the larger powers, but now the distances they can usefully reach into space that is not known to be occupied is increasingly small. This is not to say these methods are useless – the existence of some powers known only by name (such as the Flangz or the Valkan Worlds Alliance) comes from this sort of information source.But in the main, exploration is now as always, best done by sending ships into systems, despite the greater risks this presents. The single greatest risk, of course, being of appearing in the wrong space and starting a first-contact war. However, as might be noted, with the known galactic powers like the Cybertanks, Strayvians or Blastarons, more or less the worst has already happened. Any other such power would present merely a threat in their magnitude of their strength and their capabilities while those remained unknown. It is, after all, difficult to conceive of a species that could be more xenocidal than the Cybertanks we are already so familiar with.