reference point ? you mean where it is measured ? It is measured at the TRX connector.
you can get the path balance from Abis Measurement Results, or from radio measurement statistics, in alcatel systems (= RMS)
the formula is :
Path balance = (RxLev UL – MS Tx Pwr) – (RxLev DL – BTS Tx Pwr)
You can obtain these four values from a measurement result. By averaging all results on one hour, you can get a prety good idea of the path balance in each TRX.
Power control is using the same four values, so both path balance and power control will show the same effects :
If path balance = 0, the power control will attenuate the DL Tx Pwr and the UL Tx Pwr by the same amount.
But power control is not a side effect of path balance ! They are just using the same inputs, so obviously they’ll reflect the same logic.