[MLB-WIRELESS] Advice request Nepal wireless

Clae clae at tpg.com.au
Fri Feb 28 05:49:49 EST 2003

Seeking advice for a 34km link in Nepal, solar powered at one end.

Would this guy be better off using .b+ rather than .a gear?

And I guess the best other suggestion would be using 200mW cards/APs 
and the largest dishes they can find.  If 200mW hardware APs are hard 
to find, perhaps a 200mW card in a computer at the mains-powered end 
and the most powerful AP at the other.


>From: dwayne <ddraig at pobox.com>
>Date: Thu, 27 Feb 2003 03:25:04 +1100
>Subject: [BarrelfullofMonkeys] [Fwd: Re: [wireless-longhaul] unsubscribe]
>wireless in nepal!
>-------- Original Message --------
>Subject: Re: [wireless-longhaul] unsubscribe
>Date: Wed, 19 Feb 2003 10:51:59 -0800 (PST)
>From: Sage Radachowsky <sagenepal at yahoo.com>
>Reply-To: wireless-longhaul at openict.net
>To: wireless-longhaul at openict.net
>Simon asked me to post this on this list...
>I am helping to create a wireless network in Nepal to
>connect 8 villages to the internet and to each other.
>I am learning all about 802.11 technology.  There's a
>lot to learn, and it's fascinating.
>In social terms, this project has great possibilities.
>I have been to this area four times, for a total of 8
>months, and I speak fair Nepali. The ability to surf
>the web, and to communicate globally via email, would
>transform life in these villages. It would empower
>thousands of people to have their voice heard and to
>quickly gather knowledge which will empower people to
>change their lives for the better. In the midst of the
>war going on there, this would be a great step
>forward, toward peace.
>I am working with a Nepali person from one of the
>villages that will be connected, and he has some
>equipment already, and he has connected one village to
>another -- the two villages which are in direct line
>of sight, about 1 kilometer across a valley. He has
>sent email from one village to another, and served a
>website to the other village. We're also working with
>some knowledgeable and generous people in the States
>and in Belgium.
>However, the big challenge is to connect to the
>internet. The nearest city with ISP presence is 34
>kilometers away from the top of a hill. It's a direct
>line of sight, a very good line of sight, but it's a
>long distance.
>So using 802.11 technology, what do you recommend for
>this challenge?
>There is also no grid power on top of the hill so we
>will use solar panels and a battery system to power
>We have been recommended to use 802.11a (5GHz)
>technology but I have read that the higher the
>wavelength, the shorter the distance because
>attenuation is greater. (There is little chance of
>interference because this is the only wireless link in
>the whole district so far.) Also, the cost is much
>greater -- for a RedLine backhaul, for example. Cost
>is a big consideration, although reliability is also a
>big consideration.
>What antennas would you use? What power would you aim
>for? Is 100 mW or less reasonable for trying to reach
>35 kilometers? According to my calculations, it is
>possible, but that is theoretical. Would you use a
>separate bands for the backhaul and the relay to the
>other points in the network layout?
>Would a 24dBi dish-type grid be a good antenna choice?
>I think we can get these in a Chinese model for lower
>cost. How can it be aimed well without voice
>communication to the other end?  Everything is very
>remote here and there is no satellite phone either.
>Does anyone want to donate any equipment?  This is
>non-profit, totally volunteer.  I am a carpenter and I
>don't make a lot of money.  I am doing this as a
>labour of love. Nobody is making money off of it. The
>internet service will not generate revenue. After all,
>people in the village average $200 to $400 annual
>income. At most, people will give a
>We are very lucky that SmartBridges has agreed to
>provide a pair of AirPoint Pro Outdoor transceivers
>for the project at their factory cost. This is a great
>help. As some of you know, these products transmit at
>17.5 dBm -- about 50 mW. They have good receive
>sensitivity (-92dBm at 1 MB/s and -83dBm at 11 Mb/s)
>but would that transmit power be enough? I have done
>SOM calculations using the SmartBridge airPoint stats,
>and got a great SOM (22dB) at 1 Mb/s for the 34
>kilometer link but maybe I have missed something, and
>also things don't necessarily work as in the
>caluculations. (For the SOM I used 2 dB cable loss on
>Tx and Rx and 24dBi antenna gain for both ends, and
>the Tx power of 17.5dBm and receiver sensitivity of
>-92dBm. Also at 11 Mb/s the SOM was still around
>Any help/advice  greatly appreciated!
>Thanks in advance.
>Sage Radachowsky
>Boston, USA

"As a net is made up by a series of knots, so everything in this 
world is connected by a series of knots.  If anyone thinks that the 
mesh of a net is an independant, isolated thing, he is mistaken.
It is called a net because it is made up of a series of connected 
meshes, and each mesh has its place and responsibilities in relation 
to other meshes."
- The Teaching Of Buddha, (c) Bukkyo Dendo Kyokai (Buddhist Promoting 
Foundation), Tokyo 1966,

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