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[liberationtech] Can HAM radio be used for communication between health workers in rural areas with no cell connectivity?

Erich M. erich at moechel.com
Thu Mar 7 09:50:43 PST 2013


On 03/07/2013 09:26 AM, Griffin Boyce wrote:
>   How far is the distance being covered, and in what kind of terrain (flat
> plains, hills)? HAM might not even be necessary if it's fairly close
> (relatively speaking).  GMRS radios can cover several miles.  Other
> small/cheap handhelds can cover a couple of miles in ideal conditions.

Think I can add a few bits of info here. Of course are these analog
walkie talkies an absolute no go if you have to relay sensible information.

But ham operators _can_ help with their skills and Know-how. Here in AT
our ham radio club - my callsign is OE3EMB - operates a nationwide
wireless broadband backbone ring using TCP/IP. The ring is connected to
the German HAMnet, the network reaches from Southern Italy to
Scandinavia already. Self built self owned.

This is in German but there is an infrastucture graph
http://wiki.oevsv.at/index.php?title=Kategorie:Digitaler_Backbone

This is English showing the German HAMnet in 2009
http://kb9mwr.blogspot.co.at/2009/12/german-hsmm-hamnet-20.html

Essential is the availability of electrical power, of course. If that is
a tribal areal area I have some doubts.

Components are off the shelf outdoor WiFI routers. The backbone operates
in the 5 GHz WiFi band with directed antennas. At 5 GHz a much higher
power output ist allowed than on 2,4 GHz which is used to distribute
locally.
All in all the whole network consumes rather little power, one unit or
node - WiFi-Router and two planar directional antennas - is around USD
200 or less.

The antennas MUST look into "each others eye" that is another
difficulty. But if so you can bridge 20 kilometers safely using 4-7
stations, depending on terrain, offering 50 Mbit/sec - conservative
calculation.

- The net works like the internet, whether connected to the internet at
some single node, or without that.

- There is neither a problem with encryption nor with licenses. This
part of the frequency spectrum is open. Everbody can use it for wireless
broadband purposes.
my two Groschen and 73s
de
Erich OE3EMB

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