initial rural range test

[Marcelo Tosatti]

Hi James,

On Tue, Dec 12, 2006 at 08:25:29PM +1100, James Cameron wrote:
> G'day,
> 
> I've three BTest-1 units, running olpc193_A54.zip from Mitch.  I did a
> quick test this afternoon using a WOAP54G access point mounted on a step
> ladder on a remote farm.  The access point antenna was 2m above the
> ground.
> 
> I carried one unit (QUOZL 1) on a walk.  I only tried three positions:
> 200m, 500m, and 900m away.  Operating position was ears up, with me
> standing up.  I'm 186cm or so tall.  The terrain is lightly undulating,
> as can be seen in the photographs.  I made sure I could see the step
> ladder.

Great testing! Keep up the good work.

> I was able to get perfect operation at the first two positions.  Beyond
> 400m the presence of vegetation between the laptop and the access point
> began to matter.  At the 900m position, the network name was selectable
> on the user interface, but association did not succeed.

We've got a problem here: association error code is not properly reported
down to the user...

> I don't believe anything significant can be drawn from these results at
> this stage, because I don't have a baseline to compare them against, and
> the access point is an unknown.
> 
> Brief pictures ...
> 
> http://quozl.linux.org.au/olpc/2006-12-12/
> 
> (The start of the test was an ssh client connected to mpg123, playing a
> long music podcast so I'd enjoy the test more, while pinging at one
> second intervals.  The ssh stream involved a lot of buffering, so it
> wasn't a useful indication.  The ping was most useful.  Later after
> losing association and regaining it, I tested with flood ping, which is
> very useful for displaying the effect of buffered retransmitted packets
> ... the line of dots grows on loss, and recedes on gain.)
> 
> Things I'm yet to do ...
> 
> - try the other two units, to normalise the test,
> 
> - monitor received signal strength on laptop (is this available
>   anywhere?),

You can switch to a terminal and run "iwconfig" for that.

> - monitor received signal strength on access point (OpenWrt, already
>   know how to do this),
> 
> - map signal strength by GPS coordinates, seating position, laptop
>   antenna deployment mode, EBook configuration,
> 
> - map throughput,
> 
> - test ad-hoc mode (waiting for availability).