I am using site survey (EKAHAU) to do survey of one of dormitory building.
I am getting different strength of signals from different access points (Cisco LAP 1131 )
My questions are: Should I modify all access points to transmit at full power or leave it globally set?
Is there reason for tx power level to be various ( range 1 to 4 ).
In 99% of cases I'd agree with Leolaohoo, the only exception to that is if you are doing a site survey in order to do a new design/layout of ap's in the facility. If that is the end goal of your survey then yes I'd select the desired power level and hard set the AP's to that level for the duration of your survey but then return them to auto once complete. As for your other question there are many reasons why some AP's maybe at a power level of 1 and others at 4 or anywhere inbetween.. This is a function of the Auto-RF systems adjusting the power levels to comply with the specified thresholds.
Hope this helps.
I'd leave it all alone. If your APs are controller-based, then if an AP should be detected to have failed by the controller, then the controller can ramp up the transmission power.