Communications Range in T20

[SOCOM242]

Greetings All!

I'm a recent convert to all things Traveller (currently gearing up for a T20 campaign). One thing I'm trying to get a grasp on is the range and speed of communication within the Imperium and the fringe systems. I realize that the X-Boats are couriers that are as fast as their Jump Drives, but what about radio/laser communications? How far and fast can they reach? Do they use relay stations of a sort?

If you can point me to a book (I've got the CT reprints and the T20 available) or maybe a forum thread, I'd really appreciate. Looking forward to more discussions. Thanks in advance!

SOCOM, out!

 

[mike wightman]

Welcome aboard SOCOM

Radio and laser comms are only useful for inside a system, taking many years to cross the distance between star systems.

Even within a system there could be a considerable communications delay due to the distances involved.

 

[mbrinkhues]

Except Couriers (XBoats etc) all Traveller communication is "Speed of light".

Let's take earth:

A ship will drop out of jump 100 planetary diameters or 1.275.6000 km from Earth. (Earth-Moon is 384.000km) Lightspeed is 300.000km/sec so it will take about four seconds to contact earth from the egress-point one way (8 second delay in talks)

Another problem is that most comm-systems except Meson Comms are blocked by any stellar object (say the moon). And they are either pinpoint precision (Laser/Maser) so you need to know exactly where the receiver is or wide area broadcast (Radio) and you'll get potential evasdroppers.

Some more ranges (Sol is a resonably typical system):

Earth-Mars Orbit is 78 Million Kilometers (Around 4-5 Minutes at Ligh-Speed one way)

Earth-Asteroid Orbit is 149 Million Kilometers (Around 8-9 Minutes at Light Speed one way)

Depending on where the planets are, the actual distance can be much longer and blocked by that big hung of Hydrogen in the middle of the system.


So one can assume that any system with more than one settlement (IMTU: Every system with TL 9+ and a population > 1 Million) will have a number of relais stations and repeaters in system just to allow communications.

Direct radio communication does not work due to the timelag. This is more like HAM Radio or Morse. Send message, wait for other side to reply.

 

[SOCOM242]

WOW! Thank you all for the quik response! I'm getting a feel for the response time for communications. I figured lightspeed would be the logical limit. Looks like no instantaneous transmissions of any sort in this universe. Thanks again, gang!

SOCOM, out!

 

[epicenter00]

No, there's not. If you really look at the distances from Core to, say, the Spinward Marches, it's really extremely far. There's a chart in the Rebellion supplement where they talk about how fast the news of the Emperor's assassination reaches the fringes - it can take upwards of a year for news to reach areas.

It's part of the charm of the Traveller universe. After all, the Imperium has its own secret Jump-6 courier system, but the rest of us people have to use Jump-4 Xboats for news. So the government literally knows things before we do, usually weeks before the rest of us do.

 

[stofsk]

Originally posted by SOCOM242:
WOW! Thank you all for the quik response! I'm getting a feel for the response time for communications. I figured lightspeed would be the logical limit. Looks like no instantaneous transmissions of any sort in this universe. Thanks again, gang!

SOCOM, out!

The other thing to remember is that there is a (strong IMO) correlation between communications and sensor technology, eg: radio communication and radar, for example; signal fires and line of sight, etc.

What does this mean: if there is no FTL communication there shouldn't be FTL sensors either. These are things to remember about the setting. The idea is to replicate an age of steam/sail feel for the galaxy. Ships will be independent, carry the flag but kinda have to fend for themselves; it's a self-help world outside of the core sectors.

And this I believe is part of the charm of Traveller and marks it out as distinct from other, similar, space opera settings (such as Star Wars, with it's galaxy spanning hyperdrive and holonet).

 

[SOCOM242]

Originally posted by stofsk:
And this I believe is part of the charm of Traveller and marks it out as distinct from other, similar, space opera settings (such as Star Wars, with it's galaxy spanning hyperdrive and holonet).

Very true. I love space opera, but Traveller's feel makes better "heroes" IMHO, because they are more prone to getting things done for themselves, instead of say calling in the authorities instantaneously thru "subspace" and having them jump out of "warp drive" in no time...and so on, and so on.

Again, thank you all for your input!