[hackerspaces] spread spectrum para-Internet?
myrcurial at thinkhaus.org
Thu Feb 16 12:16:45 CET 2012
On 2012-02-16, at 5:46 AM, Walter van Holst wrote:
> On 2012-02-16 07:45, James Arlen wrote:
>> While theoretically possible, one runs into issues around
>> long-distance backhaul between nodes pretty quickly - land topology
>> tends to get in the way and those pesky oceans are hard to cross.
> It depends, Wireless Belgium has achieved amazing distances so far:
> I think especially in rural areas it is a lot easier to get to alternative infrastructures using unlicensed spectrum than you may realise. ISP services tend to be outright poor in rural areas whereas the amount of buildings that get in the way of WiFi or free space optics is low. I think your average farmer is willing to look into allowing a WiFi repeater on top of a grain or fodder silo if that helps him and his neighbours to get proper internet.
> OTOH, we've been looking into getting the Belgian network expanded into the Netherlands and the cost of each serious repeater node is pretty steep.
Rural isn't as easy as you might think -- I'm Canadian, pretty much all we have is rural in a way that europeans just can't grasp :)
Self-powered wifi repeater packages have been in use in rural environments for upwards of a decade - I have a reference design that I implemented a few of kicking around somewhere in the archives. You run into latency issues as you add hops, which brings us back to "when you say internet, do you mean "network of connected networks" or "just like the commercial high-speed, graphical Internet" -- if FTP-by-mail is acceptable (and it was for me 20 years ago) then you don't really care about latency.
>> Look at some of the mesh radio stuff and some of the early
>> experiments in optical networking -- there was a DIY 10mb/s optical
>> ethernet system at one point called RONJA that would haul over a
>> pretty decent distance (approx 1 mile at 10mb/s full duplex)
> The Ronja stuff is still around, the Twibright guys are amazing:
> One of the things that would be interesting to hack is finding out whether it is possible to use current generation high-power LEDs for this purpose. That might solve the current range limitations of the Ronja concept.
>> As long as you steer clear of spectra that the government considers
>> to belong to someone else, you should be fine -- and all of the old
>> software is still out there.
> The fun part is: especially free space optics is never going to be regulated at all.
Free space optics are pretty heavily regulated - you shine a light in the wrong direction and you run up against all kinds of laws - everything from neighborhood associations right up to "you flashed an airplane with your laser, enjoy prison".
And it only takes one nut-job to shut down any radiated energy source -- they're shutting down WiFi in schools where I live because of nut-job level concerns.
> Another avenue worth looking into for extreme long-distance low-bandwidth digital communication is meteor burst radio:
> HAM-licenses aren't too hard to get nowadays (they dropped the morse requirements) and given that this was feasible in the 60's, it should be doable at a much lower price now.
> A big enabler for this would be open source modular phased array antennas for the 2 meter band. Anyone knows about a design in that area?
Back to the "which Internet are you talking about" -- a lot of what we use the Internet for (as a society) is not permissable within the restrictions of amateur radio licensing.
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