ipw3945 and general WLAN questions

[Stefan Bellon <sbellon@sbellon.de>]

I have a IBM/Lenovo ThinkPad T60 which needs the ipw3945 driver in
order to make WLAN working.

I removed all of IEEE802.11 from the kernel sources of the 2.6.16
kernel, installed an up-to-date IEEE802.11 subsystem (version 1.1.12),
installed version 1.0.2 of the ipw3945 software from sourceforge and
the required firmware binary and the user space daemon.

The relevant dmesg output looks like this:

ieee80211_crypt: registered algorithm 'NULL'
ieee80211: 802.11 data/management/control stack, 1.1.12
ieee80211: Copyright (C) 2004-2005 Intel Corporation
<jketreno@linux.intel.com>
ipw3945: Intel(R) PRO/Wireless 3945 Network Connection driver for
Linux, 1.0.2d
ipw3945: Copyright(c) 2003-2006 Intel Corporation
ipw3945: Detected Intel PRO/Wireless 3945ABG Network Connection
ipw3945: Detected geography ABG (13 802.11bg channels, 23 802.11a
channels)

The WLAN LED is flickering all the time in this state. iwconfig shows
the following:

io:/home/sbellon# iwconfig eth1
eth1      unassociated  ESSID:off/any  
          Mode:Managed  Frequency=nan kHz  Access Point: Not-Associated
  
          Bit Rate:0 kb/s   Tx-Power:16 dBm   
          Retry limit:15   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality:0  Signal level:0  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:1   Missed beacon:0

Even after setting the ESSID and a key, with

# iwconfig eth1 essid <ESSID>
# iwconfig eth1 key <KEY>

there's still no link quality, no frequency, no access point, no bit
rate etc. in the iwconfig output.

And eth1 doesn't show up in ifconfig either. Should it?

What am I missing?

Although I'm quite skilled with TCP/IP networking in general, I'm
very new to WLAN and would welcome some link to a WLAN Debian HOWTO
or something similar.

In addition to the above questions: Even if I've managed to bring up
the WLAN interface by hand, how can I automate it? For wired LAN I
use DHCP at work and at home, so the notebook gets always the correct
environment configuration. Can I do something similar for WLAN as well?
Does this work by just adding eth1 to /etc/network/interfaces once
the basic low-level problems are solved?

Thanks a lot for your help already in advance!

-- 
Stefan Bellon