MP Communications Plan/Strategy

[kalos72]

As we found out in another thead:

Originally Posted by dragoon500ly

According to canon, the Project has two types of communications bases. In the module Final Watch, we are introduced to Base Kilo Alpha, a automated base and in American Out back we have the manned commo base Kilo Echo. K

Kilo Echo has a 6 person team assigned to operate it. We are also advised that it is one of a chain of 26 repeater stations, not including the Prime Base radio facilities. Of these, 8 are manned Kilo Echo types, 13 are Kilo Alpha types, 4 are attached to other Project facilities and the last is part of a power generation facility.

The main radio associated with these stations is the AN/PRC-70 which is listed as having a 4,000km with the AS-2975 antenna for CW only. Range for SSB and AM is up to 800 kilometres, range for FM is 40 kilometres.

The only real objection that I have with this network is that of using Project facilities as part of this network, if only from a security point. Anything that broadcasts cannot be detected and traced.

SSb may not be a great option since the quality appears very poor. What have you done in your game to address this?

[cosmicfish]

Originally Posted by kalos72

As we found out in another thead:



SSb may not be a great option since the quality appears very poor. What have you done in your game to address this?

Nothing. I have yet to have a team that is interested in the details of communications architecture. I like what dragoon500ly did in terms of the general architecture, but I don't want to do link budgets or atmospheric analyses just to decide whether they can talk to someone or not - that is too much like work and regardless, I prefer that to be a game-play decision. I'm not going to map out the relay stations and my world is not dependent on the number of them or their specific capabilities.

As always, YMMV.

[kalos72]

I hear ya...

It seems like many of you guys who have been playing this for awhile now, have at least some level of organization mapped out, so I thought I would ask.

I am not saying what cities did you put relay stations in necessarily, unless you know them.

But more so. while you were playing out Regional bases and the like, did comms and what the MP would do to handle the situation ever come up in your game play?

[cosmicfish]

Originally Posted by kalos72

But more so. while you were playing out Regional bases and the like, did comms and what the MP would do to handle the situation ever come up in your game play?

No, because there is no one on the other end to reply, and because making too much information on the comms grid available to players could give them ideas about mapping it. It would probably have come up post Prime Base but my teams never got farther than that.

[mmartin798]

Originally Posted by kalos72

SSb may not be a great option since the quality appears very poor. What have you done in your game to address this?

The use of SSB has some challenges, but that is not the same as very poor quality. The biggest challenge is making sure the transmitter and receiver are tuned to the same frequency, since there is no carrier signal in SSB. With a manual tuner, that is very challenging. But there are ways to mitigate this. One way is the method NASA used. Just transmit a tone of a known audio frequency and let the receiver automatically lock on to it. If we assume Morrow personnel have the ability to calibrate their radios or the radios have the ability to use a transmitted tone to fine tune the radios, then the quality of SSB not a problem.

Even so, in most games there is little reason for the teams to use SSB often. The RF spectrum in the time the game is played is very quiet, so there should be plenty of bandwidth available. SSB is very bandwidth efficient and you can have more conversations in a smaller band of frequencies than AM. So while they may use it to attempting to communicate with some Morrow facility, it is unlikely to affect game play and should only be a factor if you need spotty communications for some reason. In that case, any RF transmission method can be degraded if the game play needs it.

[kalos72]

Thanks for the information!

Can you explain the RF approach that MP took, I am not sure I follow.

[dragoon500ly]

I really don't bother with a master map of relay stations at least for the nation-wide network. My own thoughts are to place the stations on the higher peaks, or provide taller masts or use an existing mast. As far as placing such a station in a city, I would think that you would want to avoid a metropolitan area as much as possible.

[kalos72]

So to avoid getting bogged down in the details, you just assume there is a relay station working when needed, or say one stopped when your talking about a player hook or something?

Makes sense...

[ArmySGT.]

Originally Posted by kalos72

So to avoid getting bogged down in the details, you just assume there is a relay station working when needed, or say one stopped when your talking about a player hook or something?

Makes sense...

That is the ONLY way. You spend weeks planning your adventure. You make maps, generate NPCs, build up encounter groups, plot points and counter points for the local governments....

Annnnnnnnnd your player decide to drive their MPV 500 miles south to open a cache immediately upon waking.

By all means, make a minimap, make details about it, and staff it with NPCs or not. Don't worry so much about where it is until your players pick a direction to travel.

[dragoon500ly]

The more that I've read over the two canon commo bases, the more questions I have, the descriptions always point out the multitude of systems, which are impressive, but, IMHO why do these stations need anything .more than AM/SSB, FM and satellite up/downlink?

Microwave relay, while possibly more secure, is a line of sight system and requires numerous, precisely aligned towers for any commo beyond line of sight, so why include it?

[mmartin798]

Originally Posted by dragoon500ly

The more that I've read over the two canon commo bases, the more questions I have, the descriptions always point out the multitude of systems, which are impressive, but, IMHO why do these stations need anything .more than AM/SSB, FM and satellite up/downlink?

Microwave relay, while possibly more secure, is a line of sight system and requires numerous, precisely aligned towers for any commo beyond line of sight, so why include it?

One reason that comes to mind is to connect some facility to the comm base to use the sat uplink. The existing wiring and comm gear is likely damaged or destroyed. Popping up a chain of microwave relays would give you a high speed data link over a sizable distance fairly quickly. Keeping all that shiny new gear from being collected by scavengers is outside the scope of this answer.

[kalos72]

Is microwave relay a viable form of communication in that timeline?

How would it work?

[kato13]

I was reading about how high speed investment traders were planning on using microwave transmitters and stationary balloons over the Atlantic to gain microseconds on their competitors who were using satellites for communications. In their business where time is literally money it was expected they could recoup the cost of building in network in a couple of years.

I have always been in favor of the project using ballons/blimps as communications relays so that might be an option for using microwaves.

[tsofian]

I'd say higher peaks. There is a lot of chance that artificial masts or other high points will be destroyed by the war or in the aftermath, although water towers might be OK since they are comparatively sturdy

Originally Posted by dragoon500ly

I really don't bother with a master map of relay stations at least for the nation-wide network. My own thoughts are to place the stations on the higher peaks, or provide taller masts or use an existing mast. As far as placing such a station in a city, I would think that you would want to avoid a metropolitan area as much as possible.

[dragoon500ly]

The problem with microwave relay is it is a line-of-sight system, dependent on multiple towers which then form a chain that a smart villain could use to backtrack, and take out, your key bases.

Radio is basically omni-directional, unless you triangulate the broadcaster, but with frequency-hopping and encryption, that becomes harder to do.

I'm going with radio and satellite links only for the commo bases.

[cosmicfish]

Originally Posted by dragoon500ly

The problem with microwave relay is it is a line-of-sight system, dependent on multiple towers which then form a chain that a smart villain could use to backtrack, and take out, your key bases.

Radio is basically omni-directional, unless you triangulate the broadcaster, but with frequency-hopping and encryption, that becomes harder to do.

I'm going with radio and satellite links only for the commo bases.

I used to be an RF/microwave engineer before I switched to optics, so I am knowledgeable but also rusty.

To be clear, "radio frequency" generally refers to electromagnetic waves between 3 kHz and 300 GHz, which includes the 300 MHz-300 GHz section called "microwave". A microwave system is already a radio system.

Microwave is not inherently line-of-sight, the issue is simply that shorter wavelengths see more opportunities to scatter and fewer opportunities to coherently reflect. That is, you can transmit on microwave frequencies isotropically (in all directions) or directionally, it all just depends on the antenna. The range you get will depend on the antenna, the power, and some phenomena of the wavelength - at the most basic level, longer wavelengths see less attenuation and therefore have longer range. And all of this is just as true for the rest of the RF, too - if you have a 5 MHz radio you can transmit isotropically for a short range with a dipole or directionally for a longer range with a dish, all at the same power level. Also note that a communications system includes two antennas, one on transmit and another on receive, and that more broadly both sets of electronics determine whether or not the link closes. You can transmit directionally and I can receive isotropically, or vice versa, or we can both be on identical systems.

As for radio direction finding... that is a complex subject, and yes, one that the military works hard to prevent. But give me a couple of decent radios and power meters and I can do basic RDF on civilian systems, and add some decent computing power and I can make very good guesses on military.

I would not obsess over the precise technology used in the comm bases unless you are willing to actually do link budgets for them. Decide on the ranges and the directionality and that is all you will generally need.