On Sat, Feb 12, 2011 at 03:12:53PM +0000, mike cloaked wrote: > I am trying to resolve some wireless issue with a laptop running F14, > and I need to change the "sens" (i.e. Sensitivity) value for the > wireless interface. > > However when trying to run the following command as root it fails: > > iwconfig wlan0 sens -65 > > gives output: > Error for wireless request "Set Sensitivity" (8B08) : > SET failed on device wlan0 ; Operation not supported. > > and yet the command "man iwconfig" gives for this section: > sens Set the sensitivity threshold. This define how sensitive is the > card to poor operating conditions (low signal, interference). > Positive values are assumed to be the raw value used by the > hardware or a percentage, negative values are assumed to be dBm. > Depending on the hardware implementation, this parameter may > control various functions. > On modern cards, this parameter usually control handover/roaming > threshold, the lowest signal level for which the hardware > remains associated with the current Access Point. When the sig‐ > nal level goes below this threshold the card starts looking for > a new/better Access Point. Some cards may use the number of > missed beacons to trigger this. For high density of Access > Points, a higher threshold make sure the card is always associ‐ > ated with the best AP, for low density of APs, a lower threshold > minimise the number of failed handoffs. > On more ancient card this parameter usually controls the defer > threshold, the lowest signal level for which the hardware con‐ > siders the channel busy. Signal levels above this threshold make > the hardware inhibits its own transmission whereas signals > weaker than this are ignored and the hardware is free to trans‐ > mit. This is usually strongly linked to the receive threshold, > the lowest signal level for which the hardware attempts packet > reception. Proper setting of these thresholds prevent the card > to waste time on background noise while still receiving weak > transmissions. Modern designs seems to control those thresholds > automatically. > Example : > iwconfig eth0 sens -80 > iwconfig eth0 sens 2 > > So the command should work according to the man command section above. Heh...honestly, does that description seem clear to you? This part of the man page is the poster child for all that is wrong with the wireless extensions API. > Can someone tell me if there is some workaround for this or is this a bug? > > I have already reported as https://bugzilla.redhat.com/show_bug.cgi?id=677008 Neither -- the driver (like all mac80211-based drivers) simply does not support that setting. mac80211-based drivers are simple, and they don't do roaming by themselves. Instead they rely on a userland component (e.g. wpa_supplicant) to take care of roaming for them. Unfortunately, I don't know of any roaming "knobs" to turn for wpa_supplicant (or NetworkManager) -- maybe it would be nice to have one. Even if it were there, I suspect that control of that "knob" would have to flow through NetworkManager if you are using it. John -- John W. Linville The truth will set you free, but first it will linville@xxxxxxxxxx make you miserable. -- James A. Garfield -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
