[OLPC India] How to? School server implementation

Edward Cherlin echerlin at gmail.com
Fri Jan 18 23:34:09 EST 2008

On Jan 18, 2008 2:50 AM, James Cameron <quozl at laptop.org> wrote:
> G'day,
> I've tested the XO and the active antenna devices in the desert in
> Australia.

Good on you.

> On Fri, Jan 18, 2008 at 02:51:57PM +0545, sulochan acharya wrote:
> > 2. Is the active antenna  the same as any wireless router working as
> > an access point?
> No.  A typical access point consists of a radio and a small computer
> which runs an embedded operating system from flash memory.  Such
> wireless routers will lack the mesh interoperability.  Without a mesh
> gateway, the mesh will not work ... an XO that is outside the access
> point range will not be able to get to the internet through other XOs.
> > 3. What is the range of the antenna by itself? (discarding the fact
> > that the XO's can relay)
> The prototype active antenna that I've tested (2007-11-10) easily
> achieved 1km between each when held at 3m above ground.  Range is
> decreased as height is reduced, or when obstructions are in a path, or
> when other 2.4GHz radio traffic is nearby.

Many of us have been waiting to hear of a replication of the previous
50-unit test, this time over 50 km rather than 10,000 ft (3 km). In
some suitably flat and barren desert or dry lake bed. Then, of course,
we need tests in cities, rain forest, savannah, hills, high mountains,
and tundra. Are any of these planned?

> It is very difficult to predict how a location will operate.  I would
> expect a range of about 200m in an area with moderate building density,
> if the antenna is mounted above the buildings.  Plan for ranges between
> 50m and 500m.
> (Those with more knowledge please correct me.)
> --
> James Cameron    mailto:quozl at us.netrek.org     http://quozl.netrek.org/
> _______________________________________________
> Devel mailing list
> Devel at lists.laptop.org
> http://lists.laptop.org/listinfo/devel

Edward Cherlin
End Poverty at a Profit by teaching children business
"The best way to predict the future is to invent it."--Alan Kay

More information about the India mailing list