Rolling Your Own Wireless Communications System? 254
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."
This is easy! (Score:5, Funny)
2) Get a laptop (with an 802.11g card in it, of course) and backpack for each crewmember.
3) Every crew member joins the game on their laptop, sets the laptop to never suspend, throws it in their backpack, and uses headsets [csnation.net] to communicate with their team members!
Other than the sound of an explosion every three minutes or so, and the occasional "Terrorists Win!" all your communications problems are solved!
Re:This is easy! (Score:1)
Re:This is easy! (Score:2)
Not PDAs (Score:4, Insightful)
Still, if you want to try it XTEN makes a SIP softphone for PocketPC. There's probably ones for Palm OS too.
Re:This is easy! (Score:2)
Re:This is easy! (Score:2)
Re:This is easy! (Score:5, Informative)
Clearcom (Score:2, Informative)
Re:This is easy! (Score:2)
You obviously have no sense of humor. Or spelling.
Re:This is easy! (Score:2)
Seriously, I've had my fair share........so.......yeah........
Re:This is easy! (Score:2)
Re:This is easy! (Score:3, Insightful)
Shure [shure.com] makes some excellent wireless products for the music end of it. I'm sure there are other products out there that would work well. You could even be really geeky and get those Nextel [nextel.com] radio/cellphones for the crew. I've played a venue recently that the stage guys used tha
Easy solution (Score:5, Funny)
$50 Cordless phones vs $500 computers (Score:2)
Back when I was doing this at school (Score:5, Insightful)
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.
Re:Back when I was doing this at school (Score:2)
Regardless, any brew-it-yourself solution would probably be far too large, anyway. I doubt you could run VoIP on anything short of a small laptop anyway, and you certainly can't go buying those for every student.
Probably best, as you said, to stick with the older tried-and-true methods. Get newer walkie-talkies with multiple channels and keep 'em charged.
Or you could get Nextels for all the crewmembers.
Re:Back when I was doing this at school (Score:3, Interesting)
Re:Back when I was doing this at school (Score:3, Funny)
Actually not a bad idea... (Score:2)
Re:Back when I was doing this at school (Score:2)
Actually, I want VOIP on my zaurus handheld.
Let me explain why: cordless phones (not cell phones, the kind that connect a base station to the wall phone jack) are easily intercepted with consumer equipment. Tin-foil hat aside, there have been several cases of weirdos tapping their neighbors' conversations just for ki
Spread-Spectrum vs. channel-based systems. (Score:2)
Re:Back when I was doing this at school (Score:2)
A solution (Score:5, Funny)
I guess if you need to tell somebody something who's level with you then you'd have to invest in some model rocket engines or something.
Vonage (Score:1)
Re:Vonage (Score:4, Informative)
http://www.vocera.com
Re:Vonage (Score:2)
Re:Vonage (Score:2)
problems (Score:3, Insightful)
I wonder how... (Score:5, Funny)
Sheesh. It's high school, dude.
Get some cups and string (Score:2, Funny)
digital walkie talkies (Score:1)
Every problem looking like a nail. (Score:3, Interesting)
ClearCom? (Score:5, Insightful)
Re:ClearCom? (Score:5, Informative)
I'll second this suggestion.
When I was in high school, we used RadioShack walkie-talkie type headsets, with both press-to-talk (PTT) and voice activated mikes. We were always dealing with dead batteries, dropouts, and the voice activated took turns being either too sensitive, or not sensitive enough for volume the stage manager neeed to speak at (fairly quiet, sitting just off stage in the wings).
We even had interference from a Fischer-Price baby monitor, and spent an afternoon walking around the neighbourhood near the school, knocking on doors and asking people if they had any babies. I don't want to know what they thought.
The next year, we got a set of wired ClearCom headsets, and all was good in the world.
The signal was clear, and reliable.
Because they were "the" standard brand, we were able to borrow extra equipment from the local theatre company when we needed an extra headset or something.
They are also good, 'cause unlike the walkie-talkies, they come either with 1 or 2 earmuffs and do a good job of cutting down on outside noise (useful if you do bands or concerts).
Spend the money. It's not that much, espcially when you consider (1) that they'll still be chugging along in 20 years, when the RadioShack stuff is lucky to make it through 20 weeks, and (2)over those 20 years, how much are you going to be spending on batteries which you need to replace each show (you are using a fresh set each show right?)
Also, we rented them out to other groups occassionally, so you get a source of income.
Do it the right way, you won't regret it.
E.
Re:ClearCom? (Score:5, Informative)
Having a cue get missed because your batteries died, or because someone is DDOS-ing your 'intercom server' is just plain unacceptable.
If money is really tight, check ebay - I wouldn't be the slightest bit surprised to find used intercom gear on there. And really, all you need is a base station and a couple of beltpacks and headsets. If you're really cheap, buy raw 2-conductor shielded cable and 3-pin XLR connectors and build your own cables (that's what I do
Re:ClearCom? (Score:4, Informative)
ClearCom Third (Score:2, Informative)
The audio quality is as good as anything out there, the system is full duplex, so you can talk over each other. It uses standard xlr cable, so if you have a house snake you can just run it along that.
Try to get a used system, the equipment lasts forever.
My only warning about clearcom is to make shure that you don't have any short's in you cables, they can bring down the whold system. Also be cautious running it
Re:ClearCom? (Score:3, Informative)
Re:ClearCom? (Score:2)
If your school can't afford to buy a bunch, you should consider renting them, or perhaps trying to convince a local theatre group to let you borrow theirs. If you have a professionally installed PA system, the folks who supplied you with that can usually supply the belt-packs as well. Note that most of your
Re:ClearCom? (Score:2)
Yes, it does complicate things. And complication is a very bad thing in theater: if something CAN go wrong, it will. And theres enough that can already go wrong when you're doing a show.. if your communications goes wrong, it makes all those other problems that much more difficult to solve.
We used to use private-band UHF radios with headsets, or at least headphones. My dad's company had a pair of these, a
Encryption? (Score:3, Insightful)
That's simple... (Score:4, Funny)
Wait, does string count as "wireless?"
No PC (Score:2)
Re:No PC (Score:4, Insightful)
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.
Stupid technology tricks (Score:4, Insightful)
Give the Kid a Break (Score:2, Insightful)
Re:Give the Kid a Break (Score:3, Insightful)
I am definitely not a network engineer or a wireless expert, but possibly a very simple solution might be a Roger Wilco server with some bluetooth headsets. VoIP is
ClearCom (Score:3, Informative)
$800 for a CS-222 ClearCom 2 Channel Main Station is a lot of money, so another thing you may want to try are Motorola TalkAbout radios with headsets (not in VOX mode though, you don't want that in a theatre since you want to avoid unintentional chatter on the comms system). They tend to have fairly good range in my experience and if you take the time to pick out clear channels there isn't an issue with interference).
Re:ClearCom (Score:2)
Before a show we will use the pair of T5710's we have to scan for others in the area and to find a pair of clear channels. Once we find a pair of channels that works (primary and backup), we set the rest of the radios to the same channel, and make sure every one knows he backup. The system
Walkie Talkies (Score:3, Insightful)
If interference is the real issue, look into low frequency radios with a 5 watt range.
Sounds like someone wants a project.
Re:Walkie Talkies (Score:4, Insightful)
Re:Walkie Talkies (Score:5, Informative)
In a theatre, nearly everything is temporary - speakers need to be in this spot for this show, then, six weeks later, completely across the room - hence, most cabling and playback/processing equipment is portable, and certainly not run in nice steel conduit - which, sadly, leaves it susceptible to RFI.
Yes, I've also banned the use of cell phones.
(Master Electrician, Arden Theatre Company, Philadelphia, PA.)
Re:Walkie Talkies (Score:2)
I did not mention a power range -- that was the parent of my post. 5 watts is enough power to talk across town (or across country with the right antenna and frequencies, but I digress...) I imagine that even 100 mW would be plenty for these people's needs.
Unshielded lines? There's your problem. Let's hope nobody decides to use t
Re:Walkie Talkies (Score:2)
Of course, you probably already know all this :)
Cell Phones (Score:2)
Easy fix, FRS Radios (Score:4, Informative)
License required (Score:2, Insightful)
To use any GMRS-exclusive frequencies, you MUST purchase a license from the FCC and use the appropriate call sign and operating procedures.
GMRS radios are
Jim
Re:Easy fix, FRS Radios (Score:2, Interesting)
Re:Easy fix, FRS Radios (Score:3, Insightful)
FRS is not restricted in purpose. 47CFR95.193 defines the use of FRS, and the only mention of "individual" is:
There is no limitation as to the purpose of this communications with another person, other than a blanket prohibition on use in connection with a violation of federal, state, or local law. Assuming the stage crew is not supporting
Re:Easy fix, FRS Radios (Score:2, Insightful)
"You may use your FRS unit for business-related communications.
License documents are neither needed nor issued. You are provided authority to operate a FRS unit in places where the FCC regulates radio communications as long as you use only an unmodified FCC certified FRS unit. An FCC certified FRS unit has an identifying label placed on it by the manufacturer
Re:Easy fix, FRS Radios (Score:2)
Better question...digitial microphones? (Score:5, Interesting)
What I'm dreaming of is something that is purely digital, from the device the speaker wears all the way to the speaker. I envision something like a Bluetooth wireless microphone similar to the bluetooth headsets that some cellular phones use. This bluetooth microphone would relay to either a box in the speaker's pocket or inside the lecturn. This box would then use CAT-5 or 802.11 to transmit the stream as a WAV or MP3 so that it could be played on a SlimMP3 or Shuttle connected directly to the speaker system. In theory the speaker could roam freely and speak clearly and sound crystal clear.
Is there anythign like this? One place that I work for is about 100 feet from high power lines. The resulting RF interference renders even the most expensive $600-800 wireless microphone solutions worthless. Wired microphone even have a problem, even with grounding wires you still pick up pops clicks and hums over fifty feet.
So, how about it? There are plenty of devices that can take an audio stream off a network and output a sound wave? How about a device that can record the sound wave and output an audio stream?
FYI - consumer or prosumer means less than four digits...I'm sure studios and recording studios have plenty of expensive options available.
-JoeShmoe
.
Re:Better question...digitial microphones? (Score:3, Interesting)
Plenty of pros are using wireless SM58's, I guess that's UT24/58. But you've already gone there I guess, and your power lines won't move huh?
A hundred bucks can go a long way towards damned good low-Z cables. Just use real mic's! (The expensive options that the studios is still the good old wired Telefunken).
Foley guys won't touch wireless. TV news folks use AKG's and Shure's, and deal with RF issues just like you. You are
Re:Better question...digitial microphones? (Score:2)
Give me a break! As opposed to pops, clicks, hums and static when digital gets interference you just loose the signal completly!
So
As someone else told you either spend some serious dough on a real wireless system top of the line Shure or the new Audio-Technicas. Or if you're really in a high line noise envronment get a good wired mic and some super shielded cable.
Re:Better question...digitial microphones? (Score:2)
Re:Better question...digitial microphones? (Score:2)
The same thing goes for the RF interference to a wireless setup. Digital isn't a magic solution that eliminates RF problems. The better solution as far as the wireless is to just go to a frequency that the power lines aren't putting out, which probbably
Re:Better question...digitial microphones? (Score:2)
Now just wait a minute... (Score:5, Funny)
The U.S. education system must be going downhill fast.
The very latest in technology (Score:5, Funny)
Does it have to be wireless? (Score:2, Informative)
http://springtree.net/pi/econocom.html
whi c h has some packages by Production Intercom that arn't too bad price wise, and you can probably find used equipment out there for less (eBay had some real ClearCom gear last time I
Re:Does it have to be wireless? (Score:2)
Get a low-cost clone of the industry-standard ClearCom party-line intercom system. It's the tried-and-true method for theatres worldwide. There is a reason: IT WORKS! Simple setup and excellent intelligibility in noisy environments. Lots of accessories are available, such as call lights to
Any communications systems needs maintenance (Score:3, Insightful)
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.
Roll one? (Score:2)
To submitter: Why not cell phones w/ headsets? (Score:2)
GMRS or FRS (Score:2)
To solve the interference problem you could use FRS or GMRS radios with CTCSS. As long as you pick a tone no one else in the area is using, you should not hear interference even from others using the same frequency.
If you go with GMRS, someone will have to get a GMRS license. This is easy to do (no
Find you local church(es) (Score:3, Informative)
I'll bet there is more than one large church in your town, and each one has wireless gear that they use for services sunday morning, and no other time. Just talk to them in advance and borrow their gear. Most would be more than willing if you ask correctly. (and take care of the equipment)
Note that there is an art to asking. Best is to have someone in the production (actor, teacher, think outside of tech crew) ask. I'm not sure about much else because as a tech guy I don't know how to ask.
An excellent wired/wireless solution (Score:5, Informative)
Basically, it mimics a standard phone line, and any telephone device you plug in can communicate with the others. You can run long cables and use splitters [nearly] to your heart's content. For about $30-$50 per station (hundreds less than a real, however superior, Clear-Com system), you can purchase corded or cordless headset telephones which work nearly as well.
If you do that, be sure to get phones with mute capability; and if you go cordless, be sure to check on battery life and try to get phones that don't beep too loudly. You might even need to disassemble the cordless phone and disable the internal beeper to make it silent.
Two things that are really nice about true Clear-Com systems is that (1) they can be operated silently (i.e., without beeping), and (2) their mute/talk controls can be operated by feel alone -- you don't need to look at a mute LED to determine whether or not you're muted. Those features are hard to come by on unmodified corded and cordless phones.
In general, a theater intercom system needs to be absolutely reliable, and should also be full-duplex (which walkie-talkies are not, but telephones are). I'd shy away from creating a custom wireless soultion with unproven technology -- it will take much more time to develop and won't be as reliable. If anything goes wrong during a show, or if reception isn't good enough, you've got big trouble.
agreement (Score:2)
Sprint to Sprint calling (Score:2)
telex and clear com (Score:2)
VoIP wireless handsets ... (Score:2)
Better Yet. (Score:5, Insightful)
If they don't have one, perhaps its a good time to talk about splitting the cost of one.
Invest in a real system (Score:2, Insightful)
Think about it
1) The computer crashes.
2) PortabilityWill you be able to use this everywhere? You probably aren't going to take computers with you if you travel for competitions, and if you do that takes up your setup time.
3) Lag, you need real time conferencing behind the stage and can't wait even for a second of lag time if something goes wrong.
4) InterferenceMost people in the audience probably have a cell phone which operate
FRS secure channels, police/fire dept donation? (Score:2)
Best part about FRS: they're extremely cheap. Walmart has several brands for less than $10 each.
If battery life is a problem I'd recommend getting FRS radios that use as many batteries as possible. 4 AA would obviously last the longest, with 3 AA followed by 4 AAA.
If that's not
FRS? (Score:3, Interesting)
Here in Canada, we have something called (you guessed it) FRS. Stands for Family Radio Service. The handsets run for around 25-40 bux canadian. You can usually get them in a pair for 50 dollars. They put out a half watt on vhf(get about a mile of range), and operate in a band allocated ONLY to the frs. There are..14 channels?
Hm, some quick googling turns up the fact that you DO have frs down there. Other than intermod, there isnt really much interference on the band. If you are using normal walkie-talkies, try some FRS radios. If the channel you are on has interference..switch to one of the others.
Here is the bandplan from the fcc [fcc.gov].
Here are the radios at Best buy [bestbuy.com].
The only way to do this is the right way (Score:5, Informative)
Quite literally the only thing these shows have in common is the need for clear, reliable crew communications. During setup/strike (installation/teardown), crews usually have portable radios (Motorola Walkie-talkies generally), so everyone can keep in touch without shouting or running around looking for each other. Essential for big shows, unnecessary but nice for small one. However, for all shows, only "Clearcom" communications are used.
Clearcom is a brand-name of wired "party-line" communications sets. It's used generically for other brand systems, like Telex, HME, etc. It's the same thing you see camera operators on TV shoots wearing. Everyone has a headset and beltpac, and can talk to one another on a common "channel". Everything is hard-wired, and everything works, all the time, every time. The systems is used for calling show cues, as well as any other necessary communication during showtime.
However, the "wired" issue becomes a problem for some people. While audio and lighting techs can often stay put (they sit behind a board), stagehand/stage managers have to be mobile, often on stage. Usually they need to be able to communicate in a high-noise environment, and it must work reliably.
The only way to do this is via a wireless clearcom system. Telex [telex.com], HME [telex.com], and Clearcom [clearcom.com] are the big three, and all of their systems are inter-operable. I personally like HME's RadioComm, but all systems have their own benefits. Simply put, these systems are expensive but necessary. For a school situation, you can probably get away with 2 wireless stations, and 4 wired. But you can't cheap out on this. You need great headsets, and equally good beltpacs to go with them. When you're midshow, and you can't hear your cue, you'll know why.
I hope this helps. I realize that you were looking for a cheap way around the problem, but there isn't one. You'll find that with 95% of things in theater, cheaping-out never works. You buy a crappy light, or sound equipment, or cleacom, and life sux but things go on. You cheap out on rigging or construction, and people die. It's as simple as that.
-Michael Roy
A few notes (Score:2, Interesting)
Slight misappliance of science. (Score:3, Insightful)
Soon there will be 802.11-enabled mobiles in common use and all those base stations will make an awesome ad hoc network, but until then I'd suggest PRS handsets and headsets with VOX to save power.
If anyone is interested, I've developed a concept for sharing browser caches over LANs to speed up the access of all members here [family.gen.nz].
Vik
Stick with the Telex/Clear-com (Score:2, Insightful)
My Idea (Score:2, Informative)
Motorola talkabouts (Score:3, Informative)
PTT Cell phones? (Score:2, Interesting)
Challenge (Score:3, Insightful)
You obviously need voice communication without (expensive) signalling. So analog voice will do just fine. Forget computer or networking based ideas, going there is only going to sidetrack you from your goal. Remember that this is about getting your theater group to communicate, not about playing with geek toys.
Someone here has already mentioned 49 MHz headsets. Radio Shack and Maxon are common brands and those should work great for you. But if you need something with a little less interference then......
FRS, or Family Radio Service is another option. The radios are fairly inexpensive and can be had for $30 each or so. They offer multiple channels and CTCSS tones (if you don't know what that means either RTFM or get back to me, it's worth your time to understand it). Those should give you the range you're looking for. You won't get interference from businesses there, that frequency band is for non-commercial use. And if you do find someone interfering then gather information and turn them in to the FCC and your interference problem is gone.
Beyond that you could go for commercial land mobile gear. It works like FRS but you have to license a channel. You do get a lot more power and range. The drawback is that the school will have to apply for a license and that takes time. You'll have to budget $300 on up for each radio with the accessories you'll want.
If it were me I would try FRS first, a trial run with a couple of borrowed radios.
Re:GMRS Radios. (Score:2)
Re:GMRS Radios. (Score:3, Interesting)
Re:I made my own (Score:2)
2)RF modulators? Like, uh, the things you use to plug RCA (composite) video+audio input to RF (coax, RG6) output? WTF?
3)12ga wire. Ok...I can see how this would have application in a communications system. Except of course for the fact that 12ga is FUCKING HUGE and that I have NEVER IN MY FUCKING LIFE seen anyone use anything bigger than
Dont feed the.... (Score:2)
Jackass !
Re:Dont feed the.... (Score:2)
Re:A little late in the game (Score:2)
Because the "parameter of the original question", while technically interesting perhaps, and geekily cool, would be the wrong solution for the problem.
A PC-based solution will cost more and be less flexible, and be more complex, than any simple FRS/GMRS/MURS solution. Not only will there be a very high technical support requirement (e.g., what happens when the PC croaks and you need to install
Re:WVoIP *sighs* (Score:2)