weird wireless problem in hotel room

The room I had at a hotel recently had the following characteristics.

1. I got a strong signal on their wireless network, everywhere in the
room.

2. I could only get an IP address in some parts of the room. Watching
with tcpdump, I'd see my computer sending DHCP requests, and in some
parts of the room, there was a quick answer from the DHCP server. In
others, there was no answer at all.

3. The areas where I could get an IP address were small. Maybe a couple
of feet in diameter. They were fairly consistent. If I could get an IP
address on the left side of the couch in the morning, I'd still be able
to get one there that night. And if I could not get one in the morning
at the desk, I would not be able to get one that night or the next day.

(And there was no obvious patter to the areas where I could get an
address. It wasn't the case that, say, the left side of the room,
worked. Rather, it was a spot here, and a spot there, and another spot
over there, and so on).

4. If I would go to one of the spots where I could get an IP address,
get one, and then move the computer to one of the spots where I could
not get one, the one I got worked fine (until it was time to renew the
lease, and then things would stop working).

This puzzles me. Given that I have a strong signal, so it isn't the
case that I'm just barely in range of their access point or router or
whatever it is I'm connecting to, why the devil would whether or not
their DHCP server responds to me vary, and over such a short distance?

Anyone have an idea of what the heck is wrong?

Tim Smith <reply_in_group@mouse-potato.com> hath wroth:

>The room I had at a hotel recently had the following characteristics.
(...)
>This puzzles me. Given that I have a strong signal, so it isn't the
>case that I'm just barely in range of their access point or router or
>whatever it is I'm connecting to, why the devil would whether or not
>their DHCP server responds to me vary, and over such a short distance?

Multipath, reflections, and interference. My guess(tm) is that you're
looking at multiple access points on the same channel, mixed in with
traffic from other clients in the hotel. Possibly some additional
interference from other wireless LAN's, especially municipal networks.
In other words, interference. If you fire up Kismet on your
unspecified operating system, you might be able to see these (if the
access points are broadcasting their SSID).

Look at the signal quality indicator rather than the signal strength.
You can have a very strong signal, but if there's junk from other
users on the channel(s), then your signal quality will suck.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558