Hello!

I'm one of the 1.7 million people currently coding a survival game set in a zombie-infested post-apocalyptic world. I'm thinking of adding some kind of a radio system to the game but unfortunately I don't have any expertise in the field of radio transmissions and frequencies, so I'm looking for some help. I'm not aiming for ultra realism, but it would be nice to make everything at least remotely realistic. Maybe there's a radio amateur lurking in the forum who could give me some pointers.

My idea is that the player can find some kind of a battery-run radio receiver and try to listen to different frequencies. There would be some kind of a "government" frequency, some more local S.O.S. signals etc. and maybe even a rogue radio station of some kind. Being able to hear different signals would depend strongly on player's position and his altitude.

Which set of radio frequencies would likely be used in a situation where the civilization has collapsed? What kind of gadgets and technology would transmitting/receiving require? Any relative information and ideas are much appreciated.

(edit: I'm sorry if this is not the right sub-forum! Feel free to move it.)

Perhaps this resource will be of use to you: https://en.wikipedia.org/wiki/Amateur_radio

Hi! I run a postapocalyptic amateur radio club. We communicate with people all over the world using the kind of gear you're thinking of. Want to pick my brain?

http://www.wccorp.org

Hello!

I'm one of the 1.7 million people currently coding a survival game set in a zombie-infested post-apocalyptic world.

Then you have quite a big dev team there

There's an Arma mod called ACRE that adds a semi-realistic radio system.

Maybe you can get some good ideas from the links in their wiki:

http://tracker.idi-systems.com/projects/acre/wiki

You will likely want to sit down and look at the history of radio communications. Post Apocalyptic times will mean a far less cluttered radio spectrum in most cases, as there would be far fewer people transmitting. (Possibly some of it will be less useful due to environmental effects)

So much of it will be cobbled together with different era of tech, depending on what tools and knowledge are available at the time. Totally understandable to have someone transmitting with a very crude spark gap pulse code (morse code) working next to someone with a digital field video point to point radio. One would be something made from materials on hand, the other most likely a surviving relic.

Also don't forget the issues of radio location, bandwidth, and power. It is possible for someone to be heard by you, but you being unable to reply. Someone can use up a huge amount of bandwidth on a high power signal, which drowns out other signals in an area. (It isn't unusual for some radio operators to use max legal power on their signals to talk to someone on the other side of a town, which is basically just their way of showing off big their gear is. Highly annoying to other operators.)

Most probably HAM radio over large distances, and CB radio (like truckers use) or improvised spark-gap transmitters over intermediate/short distances. Those would be most prominent near the beginning of the scenario, and would probably decay/evolve over time as equipment breaks and needs a replacement cobbled together.

A local radio station could be 'taken over' by people and utilized, but usually the transmitter itself is far away, and analog broadcasts require a great deal of power (proportional to their signal range) -- they'd need a significant power source that's still intact, and may have reduced range based on available power.

AM radio can bounce off the upper atmosphere, and with the relatively low amount of other interfering signals and clear skies, can reach a great distance. I remember being young, growing up in Minnesota, we could sometimes pick up AM radio stations from Quebec, Japan, and Russia when conditions were right. HAM radio is the same. This might be a believable way to get news about how the rest of the world is doing if language is not a barrier.

Post Apocalyptic times will mean a far less cluttered radio spectrum in most cases, as there would be far fewer people transmitting. (Possibly some of it will be less useful due to environmental effects)

Obviously depending on what type of postapocalyptic scenario we're talking about, this may or may not be opposite of the case. Currently there are approximately 765,000 licensed amateur radio operators in the US and Canada. During the ARRL Field Day 2012, by leaps and bounds the largest emergency communications exercise in the US and Canada, 2,657 stations reported their logs. This represents probably ~30,000 total operators. This weekend represents an absolute peak of cluttered radio spectrum. This during a weekend where the vast majority of licensed operators are apparently not transmitting.

Now imagine a world where all the "normal" networks (internet, landline phone, cell networks) have been rendered useless. I'd say whoever is left that has access to a ham radio is going to be working that thing during all hours in order to provide neccessary communication services to their local communities / bands of raiders / cannibal tribes.

If we're looking at an extinction level event where some fraction of a percent of the people have survived, obviously the bands will be very quiet. If we're looking at a devolution into feudal factions and small villages, I think that there is data to support the theory that it will be hard to get a word in edgewise on popular, well propagating bands such as 20m.

Thanks to everyone, great and useful answers until now! I'll keep doing research and see what comes out...

This might be a dumb idea but at the other end of the spectrum I suggest adding satellite radio that doesn't "do" anything but broadcasts old news/music from times before the apocalypse, in an eery sort of way. For instance even if civilization collapsed it's likely there would still be satellites in service for at least 5-10 years (after which their orbit eventually decays). They could also be a minor gameplay element e.g. hacking them remotely or something to increase your communications range :p (that would require advanced technology though)

Again just an idea, I have no idea if this is even plausible, but if it is, then it would certainly seem as though those satellites would have significant strategic importance given their wide range and rather safe position (especially spy satellites).