(keitai-l) Re: International Usage

From: Curt Sampson <cjs_at_cynic.net>
Date: 07/10/02
Message-ID: <[email protected]>
On Tue, 9 Jul 2002, Benjamin wrote:

> >  is 5 GHz, yes, and
> > is spec'd at 45 Mbps. In reality, you're lucky to get 20 Mbps out of it,
> > and the range is generally under 10m indoors.
> I am surprised to hear that. Why would it be spec'd at 45 if you can
> only hope to get less than half of that ?

Why is 802.11b spec'd at 11 Mbps when you almost never get more
than 7 Mbps, and often get 1-2 Mbps?

The "spec'd" limit is a theoretical limit, and of course it's the one
all the marketing folks quote because it's the highest number. But next
time you're using 802.11b, for example, have a look at what rate your
card is actually running at, and then try using netpipe or another
benchmark to see what throughput you're actually getting.

> However, if you were to use this as point to point, from roof-top to
> roof-top or from roof-top to a fixed spot at ground level, provided
> there is clear line of sight, I would think that it should be possible
> with uni-directional antennae, proper alignment and calibration, to get
> close to the maximum bandwidth as per spec. Wouldn't you think so?

I honestly don't know. I am not familiar enough with 5 GHz to know its
propagation characteristics well. But my friend found his real-world
experience with an installation that was done under pretty darn good
conditions (indoors, relatively small area) to be very disappointing.

Curt Sampson  <cjs_at_cynic.net>   +81 90 7737 2974   http://www.netbsd.org
    Don't you know, in this new Dark Age, we're all light.  --XTC
Received on Wed Jul 10 07:09:28 2002