[harshreality]

Wouldn't SDRs be a lot more useful for creating higher-bandwidth wireless networks in the sort of disaster where the FCC opens up other frequency ranges?

The amateur radio regulation regime and common ham radios work well for small numbers of small messages sent around in a well-regulated way, without the government initiating a frequency band jubilee. But beyond that, HAM radios are limited, even if they're modded, and the cheap SDRs are even cheaper than baofeng handhelds, so where does that leave amateur radio in a real frequency free-for-all? I think what would matter is, as mentioned above, availability of SDRs, and secondly, parties of people tracking down transmitters that are messing up the ad-hoc sdr wireless nets.

[Florin_Andrei]

Sure, but everything has to be ready, prepared and exercised before anything happens. Whatever plan you may conceive, you have to do plenty of test runs in advance. After it happens, it's chaos, it's too late to start new initiatives.

And there are caveats anyway.

For local connections, some kind of WiFi mesh might still be the best option.

For long distance, I don't think you can currently use anything but proper HAM equipment, and fairly large power at that. For a reliable connection, especially at good bandwidth, you need lots of power and a good antenna. But if you blow standards out of the water, and start pumping out huge bandwidths at huge powers, you run again into a tragedy of commons - you're taking up large chunks of spectrum over entire continents.

There is no free lunch.

[acidburnNSA]

As a fellow ham, I have to say: guys, guys... it's ham, not HAM. Other than that I totally agree with you.

The (VHF and UHF) ham bands will send data a few tens of kilometers with good messaging bandwidth. Here in Seattle there's a Monday-night digital net through a repeater on the Columbia tower where folks send text messages and some (slow) photos on 444.55 MHz. Typical speeds are like 9600 baud.

As you mention, when you go down to the HF bands like 20m you can transmit and receive around the world, but there's far less bandwidth. The tragedy of the commons is right on.

I've operated PSK31 (which runs at 31 baud) worldwide on 20m and it's pretty much a chatroom. You can get a lot said with that, but you certainly won't be browsing the web.

It would be cool to play around with connecting 2.4 GHz local wifi meshnets with ham repeaters at ranges of say 50 km. Then you'd have nice fast local communication with reasonable long distance. .