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Rolling Your Own Wireless Communications System?
nuggetman asks: "My high school, like most others, has a theater program. One critical element of the show is the tech crew - the group of people behind the scenes who keep it all running. Communication between the stage manager (myself) and crew members (as well as between crew members) is critical. For this job right now, we're using standard hand-held walkie-talkies. They get the job done, but they're susceptible to dead batteries, incompatibility between VOX headsets, and interference from janitors, the office, hall monitors, and even the local McDonald's. We've been wanting to invest in a theater-communication system, but they can run extremely expensive. Is there any hardware out there that could use a standard PC (Linux or Windows) and some wireless headsets to roll your own communication system that could cover a long enough range (say the theater which is the size of a gym plus a decent range outside it) at a low enough cost? Our school just installed 802.11b/g throughout the hallways, so we could tap into that if necessary and add our own router near the stage if we had to."
... which was admittedly about 18 years ago, we were happy to have the very latest technology... microphones and headphones (well, it was on a school-sized budget :-)
To be honest, I'd be surprised if WiFi would help you very much - it'd have to be a VoIP network, which isn't an obvious use of WiFi (the range is too short - most people would simply shout!)
Bluetooth might be an option, but they're basically clever walkie-talkies. Buy some rechargeable batteries and carry them. Sometimes the "clever" solution is the low-tech one...
Simon.
Physicists get Hadrons!
I'm sure there are probably a lot of problems with interference, but shouldn't it be possible to just get better walkie-talkies? Computers have their own problems too, and I'd imagine that any device you are using to communicate will have dead battery problems (unless you want to have 20 ft cords running all over the place).
Just buy a few ClearCom headsets. If wireless costs too much for you, get the old-style models and some lengths of XLR cable. Why waste time with all this computer stuff? It just complicates things. Use the simplest solution.
Why not buy some new handheld walki-talkies that have built in encryption (digital), wouldn't that be cheaper/easier than any computer network?
No, this is just silly. A laptop is going to be far more expensive than some high-quality two-way radios from Motorola or the like. Even if you already had the laptop, there's nothing that allows you to easily tap into VOIP via independent headsets. I'm not sure why regular, quality two-way radios (at $40 for a pair with rechargeable batteries) isn't good enough for this simple application?
More information for my original post.
Consider the cost of your solution vs the cost of a regular system.
CS-222 Clearcom 2 channel base station: $876
Belt pack: $238
Headset: $149
Now you'll need a headset for the base station (which is a station by its self). So say you need 1 stage left, 1 stage right, and your base station will be at FOH for sound/lighting. That takes a basic solution to $1799 without XLR cables. Buying used you could probably save even more. Remember, not every single person needs a headset. You basically need someone stage left, stage right and FOH to give messages and give cues. I was in highschool theator and I know how much everyone loves to wear the headset to sound important. I can also remember how many cues people missed because they were messing around on them.
The problems you cite are universal for portable communications systems. Batteries going dead, bad headsets etc. The key is planning and maintenance. If it is critical to the show then make darn sure the batteries are charged before the show starts and if one doesn't last the entire show then dispose of it. (Nicads and nickel-metal hydride need to be disposed of properly, Radio Shack does this for free) Keep a couple of spare radios ready to go and charge some extra batteries as well.
The better route to go is to get a license for your own radio channel and use higher end radios like police and firemen do. Schools often have a business band license for buses or maintenance that you could use on the off hours, this keeps other people off your frequency. The radios cost more but you are paying for reliability.
Don't whine that you don't have the money, get a system designed by your local radio (Motorola) dealer and then start getting the money through grants and donations. I get solicited all the time for free stuff and sometimes the dealers can hook you up with a corporation that is changing systems out and looking for a place to donate the old (but good) equipment too.
The main thing is plan ahead, and plan for things not going perfectly.
Forget about Wifi PDAs. Since Wifi is an always-on data connection, it's inefficient with power. Battery life sucks and you can't get headsets for them. Most have headphone jacks but no microphone jacks.
Still, if you want to try it XTEN makes a SIP softphone for PocketPC. There's probably ones for Palm OS too.
Don't buy anything. Work on sharing the football team's headsets. They probably have a bigger budget than your theatre department anyways. This should work out as long as you never have a performance during a game, which you should never do anyways!!
If they don't have one, perhaps its a good time to talk about splitting the cost of one.