Thursday, February 4, 2010

Better Ways to Use Foreign Aid

Like yesterday, today marks a new peak in the size of Jalalabad's Fabfi network--26 simultaneous live nodes. More importantly, the way those nodes are being made is changing.

When we first brought FabFi to Afghanistan we brought our own idea of the best solution. It looked something like the photo at right. With a little training, our afghan friends figured out how to copy reflectors like the one in the photo and make links. That's super cool and all, but you can't always get nice plywood and wire mesh and acrylic and Shop Bot time when you want to make a link. Maybe it's the middle of the night and the lab is closed. Maybe you spent all your money on a router and all you have left for a reflector is the junk in your back yard. That, dear world, is when you IMPROVISE:




Pictured above is a makeshift reflector constructed from pieces of board, wire, a plastic tub and, ironically enough, a couple of USAID vegetable oil cans that was made today by Hameed, Rahmat and their friend "Mr. Willy". It is TOTALLY AWESOME, and EXACTLY what Fab is all about.

For those of you who are suckers for numbers, the reflector links up just shy of -71dBm at about 1km, giving it a gain of somewhere between 5 and 6dBi. With a little tweaking and a true parabolic shape, it could easily be as powerful as the small FabFi pictured above (which is roughly 8-10dBi depending on materials)

For me, the irony of the last photo above is particularly acute when one considers that an 18-month World Bank funded infrastructure project to bring internet connectivity to Afghanistan began more than SEVEN YEARS ago and only made its first international link this June. That project, despite hundreds of millions of dollars in funding, is still far from being complete. Meanwhile, FabLabbers are building useful infrastructure for pennies on the dollar out of their garbage.

Where would you put YOUR money?

4 comments:

  1. Nice and very impressive. Best wishes four your country andy our people from Europe.

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  2. FabFi should get one penny out of every Aid-Dollar spend in any 3rd world country on communication, then, I am sure, you'd get 80 % of the overall work done and be hard put where to spend all the leftover money you'd accumulate!!! Send a Letter to Obama, he's just the guy to get the joke and make it work!
    Best of Luck

    Werner from Montreal

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  3. How did you determine the approximate dBi of the antenna based on your receive signal (-71dB) and the distance (1km)?

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  4. @Anonymous: We know the link distance, frequency and transmit power of the radio. We then measured the receive strength using the router's software and backed out the gain from the fundamental physics, using an online SOM calculator. SOM calculators are linked in this post: http://fabfiblog.fabfolk.com/2008/12/antenna-resources.html

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