Only in designated spectrum. And even then you need to register with the FCC and have the device type accepted. Take a look at all devices that transmit anything and note the FCCID string that is on said device. Those fall under the Part 95 licensing.
Remember too that many areas are too far out for even Wireless. And they are not that far from major civilization.
A good friend of mine lives in Tuscola Michigan. This very small town is about 5 miles East of Frankenmuth, MI. The only reliable means of communication he has is the POTS line. I have personally had Verizon, T-Mobile, Sprint, Nextel, and AT&T cell phones on his property. Of those the only one that ever got reliable communication was the Nextel. And that was only in his front yard. For some odd reason it wouldn't connect in his back yard.
Mind you, Frankenmuth, MI is not a huge city here, but it is certainly very well populated so it's not wasteland but it's not metropolis either. This falls true for many areas in Michigan I have been to.
And as for VoIP over satellite, good luck! Propagation delay on a satellite is upwards of a second for network communication. Anything real-time is unusable. This includes any games, etc. That's provided you have one of the newer systems that doesn't REQUIRE a POTS line for the uplink.
Note that anything over 100ms for delay renders the VoIP problematic, if not useless. I am a VoIP engineer for a living. We have to take all of this in to consideration before we even propose a solution to a customer.
Two notes only. Each coil produces one note. At least that is how they were when I saw em a couple of years ago and the setup looks the same.
Sound in real life. Loud. Really freaking loud. These are 7 foot tall units putting out sparks around 7-10 feet controlled. Sound is point source to the coil it is originating from, sorta. The sorta being pretty much the area of the spark itself, so the source is wider than one would think. Highest and lowest dunno, though it had a very good audible range. The sound was a bit harsh due to the nature of how it was being generated and the noise from the bolts themselves.
All in all darned impressive. Very well done and they were very knowledgeable. I had the chance to sit down and chat with them for a little bit before they left and all I can say is "wow".
In this case I would not want to be the recipient of the electric bill. These are not your father's tesla coils. These are fairly low voltage very high current devices. The feed they got from the hotel at Penguicon a few years back was a 220V 50A and I remember them having an ammeter on the line to make sure they didn't exceed the rating and trip the circuit.
They run high current at lower voltage to be able to use solid state switching devices to drive the coil. No rotary spark gap here just a bunch of IGBTs and other fun silicon the size of your fist.
Based on chatting with them when they did Penguicon in Michigan they use a control circuit to turn the coils on and off at a specific rate. This allows them to use the actual lightning breaks per second to generate sound. E.g. 128 breaks per second roughly equals a sound at 128 Hz.
When they were coming out here they asked us to provide 2 note MIDI files for playing. If I remember correctly the computer uses MIDI to drive the control circuitry that is fed optically (to avoid coupling to the coil itself) to the drive electronics in the coil. So not so much pre-programmed as interpreted.
Really neat technology they have put together and darned loud! I wonder if they ever built the other two notes they talked about building at Penguicon. Hearing 4 of those going in harmony would be sweet!