That may differ from country to country though. I only sniffed to it ~30 years ago as a member of a local youth club (a socialist version of scouts) so the license was held by the club but man, did we have strict rules what was allowed and what not!

Err, sorry about this nostalgic off-topic diversion

Estel, I think if PSTN is what we want there is plenty of open code for 14400 win modems. AFAIK it is code to control a sound card with a second i/o and matching for PSTN. The code will fall back to whatever bit rate is sustainable, like in the old days using acoustic couplers.

yeah i felt the same and i deleted the post long before and you need not to say please for that

It=? I lost idea about which of the projects you're talking about.

What interest us, is FOSS software, that can communicate through audio link (of varying quality), using either (as in "able to use this *or* that) N900 with it's known audio input/output ports, or standard computer with sound output/input.

What we use for that audio link - PSTN or ham radio or whatever - doesn't matter. As long as we're able to use any available audio link, *not* be forced to have one of them handy.

/Estel

Another great way (at least where i live) to get data when experiencing a blackout, is residential wifi mesh isps. Theres a network that uses microwave backhaul to link small remote communities to metropolitan areas.

All the subscribers have directional (i assume) modified dd-wrt routers in them, that connect via pptp to AP's located ~1m from the furthest client, and have backup power when AC is down.

All you need, is a dish wifi antenna, a signal amplifier (1w works good), and a ddwrt router configured as an client.

You connect to their unsecured AP's, and are presented with a billing/login page upon opening a web page. You can buy a day/week/month pass.

Its what i do when the power goes out. But since my neighbors host one of the AP's, i don't need an amplifier or parabolic wifi antenna, just 2 flat directional ones, and a ddwrt rosewill router setup for wifi client connection. Power them off a AGM sla bank/voltage regulator, and your in business.

But, long range wifi with signal amps and homemade antennas can acheive decent range, anywere from miles to tens of miles, and the record i think is in hundreds.

Of course that requires both endpoints to have the same transmission/recieveing output power, and directional antenna, but no licensing like ham.

Or you could use a liscenced ham op's equipment as the backhaul if you wanted. IE wifi mesh locally -> wifi AP hosted by ham operator, and on the other end a ham operator who routes that into an ISP connection/internet however they may go about it.

I'm afraid, that your AP operator could get shut down like every other ISP, in case of real emergency (think big crisis and martial law). Independence from "big brother(s)" is key think in this thread - which, BTW, evolved voice-only transfer, into data-transfer of any type (after all, voice send through electronic is a type of data...).

Nevertheless, mesh WiFi network (really independent from providers) is great thing. It's pity, that it never worked on N900, and instead of getting fixed, it got disabled in KP (modules for it cashed crashes, or something like that). Not enough knowledgeable enough people interested in bringing them to workable state, I think.

/Estel

You're getting a bit off point.
Back on the subject ... check out this.
http://code.google.com/p/whisper-encryption/
"We introduce a software prototype for analogue speech scrambling which acts as a transparent encryption layer for any subsequent digital processing. This allows the user to secure his voice communication regardless of the voice client (and therefore compression algorithm) and can theoretically also be used for mobile phones."
This project looks nice, and It's licensed under GPLv2.... and as far as I remember ( I took a fast look over it some time ago ) the only thing missing on N900 to get it working was lib cryptopp (witch I coudnt compile ..my C skills sux! )...
Anyway I think the main idea here is about encryption software working with pre-shared keys (probably both devices are n900/n9) and the communication is transmiter throu the gsm network.