How to decrease the transmission range for Lucen't Orinoco

[David Gibson]

On Mon, Oct 07, 2002 at 12:21:06PM +0800, Ankur Jain wrote:
> Hello

> I want to know how can we decrease the transmission range of
> Lucent's Orinoco Card (Silver) to 5-10m.

Um... wrap the antenna in foil?

> Actually, I am making the testbed for mobile ad hoc networks. As our
> office space is limited, we have to place 10-12 nodes in such a way
> that they are at max 10-15m away. But, presently, the card range is
> around 80-100m. So, our whole purpose of using ad hoc mode will not
> be satisfied.

> So, could you tell me how to decrease the range. I tried changing
> the sensitivity threshold level using iwconfig. But, I can't see any
> change. Also, with my card, there is only three levels of
> sensitivity - 0,1,2,3. One of my friend is using Cisco card. He has
> 65536 levels. So, we changed the sensitivity level from 0 to 65536
> on his card and tried to connect to the base station which is placed
> at the other end of the office (30-40 m away). We can't experience
> any change is signal quality.

Yeah, I'm not sure exactly what the "sensitivity" means on these
cards.  I'm not sure it's quite what you'd think it would mean.

> I will be highly grateful if you can tell me what to do in this
> case. Is it possible with cards of some other vendors?

As far as I know there isn't any software way of doing this - I don't
believe the Lucent cards have software controllable Tx power.  So I
think you'll have to look at physicall crippling the cards - either by
shielding their antennas somehow, or by using an external antenna of
really terrible design.

I'm CCing this reply to the wireless at samba.org list, since it really
has more to do with wireless issues in general than the orinoco driver
specifically.

-- 
David Gibson			| For every complex problem there is a
david at gibson.dropbear.id.au	| solution which is simple, neat and
				| wrong.
http://www.ozlabs.org/people/dgibson