[Orinoco-users] When is scanning mode available

[g***@bt.com]

Hi

I am running an Orinoco Gold PCMCIA Wifi Card in a 2.6.16 kernel Linux
system [laptop].
I notice that right after I insert the card I can successfully scan for
all Access Points (APs)
within range [with various different ESSIDs]. After I connect to one the
APs found in the scan,
use it for a while and then disconnect from the AP, then try to run a
second scan

I tried the following sequence ...

(1) Insert the Orinoco Gold card
(2) I can now successfully scan for all Access Points (APs) within range
with various
ESSIDs being available
(3) Connect to one AP found and use that WiFi network for a while
(4) Disconnect from the AP
(5) Run a scan again, this time it fails and shows no APs found
[Resource not available message from iwlist eth1 scan]
(6) I can only get the device to scan again successfully if I remove it
from the PCMCIA slot and return to step (2)

So is scanning mode unavailable after connecting to an AP ?
Is there a software means e.g. in the Linux wireless extensions to scan
more than once ? Do I need to re-initialize the
Card to scan again ? If so How can I do this via the wireless extensions
?

Thanks for any info.
BR
Graeme

Dr Graeme N Brown
Mobility Research R & V

BT Group Chief Technology Office
B28 pp 2B
Adastral Park
Ipswich
Suffolk
United Kingdom
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[Jean Tourrilhes]

Post by g***@bt.com
Hi
I am running an Orinoco Gold PCMCIA Wifi Card in a 2.6.16 kernel Linux
system [laptop].
I notice that right after I insert the card I can successfully scan for
all Access Points (APs)
within range [with various different ESSIDs]. After I connect to one the
APs found in the scan,
use it for a while and then disconnect from the AP, then try to run a
second scan
I tried the following sequence ...
(1) Insert the Orinoco Gold card
(2) I can now successfully scan for all Access Points (APs) within range
with various
ESSIDs being available
(3) Connect to one AP found and use that WiFi network for a while
(4) Disconnect from the AP
(5) Run a scan again, this time it fails and shows no APs found
[Resource not available message from iwlist eth1 scan]
(6) I can only get the device to scan again successfully if I remove it
from the PCMCIA slot and return to step (2)
So is scanning mode unavailable after connecting to an AP ?
Is there a software means e.g. in the Linux wireless extensions to scan
more than once ? Do I need to re-initialize the
Card to scan again ? If so How can I do this via the wireless extensions
?
Thanks for any info.
BR
Graeme

The Orinoco hardware is a bit limited in what it can do, other
hardware don't have this limitation. Once an ESSID is set, scanning
only search for that ESSID, and ignore other ESSID. In IEEE parlance,
it do only active scan when an ESSID is set. This has the advantage of
beeing faster...
If you want to scan all ESSIDs, you would have to do :
--------------------------------------
# iwconfig eth0 mode managed essid any
# iwlist eth0 scan
# iwconfig eth0 mode <my-mode> essid <my-essid>
--------------------------------------

Good luck...

Jean