Considerations for a Space Opera Setting: FTL Communication

22:55 Tue 05 Apr 2011
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I’m still thinking about my large-scale science-fiction/space opera project, and the next major consideration after FTL travel is faster-than-light communication.

While I’ve already decided that FTL travel is possible in this universe, a valid and underexplored variant is where FTL travel isn’t possible but FTL communication is.

Expense, reliability, speed, and bandwidth are all important characteristics, but I’ll dispense with reliability here because it seems like an invitation to unsavory plot shenanigans (e.g. the protagonists escape when a convenient “ion storm” or “disturbance in the aether” foul up communications at just the right time). It also seems that no large-scale civilization could or would survive without having solved the reliability issue by some means. (Note however that the Warhammer 40,000 universe plays with this in interesting ways.)

As regards speed, the first issue is whether or not FTL communication is faster than FTL travel. If not, then the fastest mode of communication will be by messenger ships designed for the purpose, and other FTL communication forms will be of secondary importance. This question is particularly critical in terms of military conflict and history, boiling down to: can communications move faster than the fleet? If not, this suggests to me a less stable political system, where events move faster than messages about those events and it’s easier for defending forces to be caught unawares even on a very large scale. It also plays with economics, allowing more potential for arbitrage and fostering demand for expensive messenger services; the larger the gap between travel and communication speed, the more important these are.

In this universe, FTL communication will be faster. This allows for centralized command structures to operate more efficiently, makes FTL travel less of an escape for those on the run, speeds the pace of events by allowing all participants to react more quickly, and increases financial/economic interdependence.

A related issue here is whether or not ships travelling at FTL speeds are able to access FTL communications; my hunch is that any ability to do so is quite recent, is regarded as a significant strategic advantage, and that this may well provide a plot point.

So, how fast is it? Exact numbers don’t matter, but what’s more important is whether or not news crosses the known universe so that there’s not much lag. The faster it is, the more connected the culture is, and I’m leaning towards it being highly connected, so that news travels quickly indeed, and crosses the entire known realms in a matter of days at most; there may be speed bumps in the communications grid related to bandwidth and/or expense, or other local conditions, but these are issues more likely to affect the periphery and not the center.

Bandwidth is related to expense, but technical or other non-economic issues could constrain it. Extremely low-bandwidth communications would still be incredibly useful, particularly for military, political, and economic purposes, which would probable have a stranglehold on it. However, as I want this to be a more connected culture, I’m going to go ahead with high-bandwidth, so that colossal amounts of information can be transmitted rapidly; note that this also enables the equivalent of the internet spread across space, which clearly has a profound affect on how things in general work.

Expense must be reasonably low in order for high levels of connectedness, but the question of infrastructure arises here. Is it quick to set up, you just need some kind of transmitter and a power source and that’s it? Or do planets require highly expensive machinery that’s centralized? Do relay points have to be “hung” in warp space, and if so, how expensive is this? Would this mean that beyond some point on the periphery, ships do travel faster than communications? I’m not sure about my answers to this, but I’m tending towards something like that, where relay points of some kind have to be established at considerable expense, and while this is a routine and well-understood process, the network expands at some lag behind the extent of human activity. Transmitters will be relatively closely watched by governmental forces, but they don’t have an absolute monopoly. Ships out beyond the network can still communicate, but with far less bandwidth and possibly even less speed, or with some draconian relationship between speed and power requirements.

Because FTL communication during FTL travel has only recently become possible and is still rare, the emergence of a ship from warp space is an extremely significant moment informationally: the first thing any ship is going to do is re-establish connections to the network and download a lot of information. Protocols for this would have to be well-defined, but of course there are all kinds of opportunities there for trickery, fraud, and deception.


  • FTL communication is definitely present.
  • It’s faster than FTL travel.
  • It’s really fast, so that messages can cross the entire setting in days or less.
  • It’s cheap and highly available in the center, growing less so at the edges.
  • It’s an expanding network, and humans definitely live outside it.
  • It requires a lot of expensive infrastructure, and is not wholly monopolized by state or other actors.
  • It’s only recently become possible to use while engaged in FTL travel.
  • It’s possible outside the network, but has significant restrictions.

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