B.1 Open loop control

3GPP45.008GSM/EDGE Radio subsystem link controlTS

A pure open loop is achieved by setting  = 1 and keeping _CH constant. The output power will than be:

P = ₀ – _CH – C – 48

The value _CH can be calculated as follows to give a target value for the received signal, SS_b, at the BTS.

The received signal level at the MS:
SS_m = P_BTS – P_b – L

where P_BTS = BTS maximum output power
P_b = BTS power reduction due to power control
L = path loss

The C value (normalised received signal level):
C = SS_m + P_b = P_BTS – L

The MS output power: P = ₀ – _CH – C – 48 = ₀ – _CH – P_BTS + L – 48

The received signal level at the BTS:
SS_b = P – L = ₀ – _CH – P_BTS – 48

The constant value of _CH:
_CH = ₀ – P_BTS – SS_b -48