Hi Konrad,
Maybe this is the default value you were referring to?
Transmit Power Control Algorithm
The TPC algorithm, run at an un-modifiable ten-minute interval, is used by the RF Group Leader to determine APs RF proximities and adjust each band?s transmit power level downward, as necessary. this is performed in order to limit excessive cell overlap and co-channel interference.
Each AP reports an RSSI-ordered list of all neighboring APs. Provided an AP has three or more neighboring APs, the RF Group Leader applies the TPC algorithm on a per-band, per-AP basis in order to adjust AP power transmit levels downward such that the third loudest neighbor AP is heard at a signal level of -65dBm (default value) or lower.
Power changes are only made when the third loudest neighbor of a given AP is heard at a signal level higher than the default value of -65 dBm.
Note: When all APs boot up for the first time, the APs transmit at their maximum power levels. Also, if the APs do not see each other with a -65dBm (default value), they push the power level up to the maximum in order to achieve this. If you go to the Controller CLI and issue the show ap auto-rf 802.11b command, there is a Nearby APs section near the bottom of the command output. In this section, you find the dBm listing. If this dBm listing has values more than -65, then the AP transmit power is at the maximum. This is tweakable to an extent. You can issue the Config advanced 802.11b tx-power-control-thresh <-50 to -80> command.
From this excellent doc (Thanks Ben!);
http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a008072c759.shtml
Hope this helps!
Rob
