et cell RSCPs. The RNC commands handover when the handover criteria is fulfilled. Connected Mode Power Control Transmission power is one of limiting resources of the WCDMA system. Common channels (CCHs) are transmitted with fixed output power and the power control algorithm minimizes the transmission power for dedicated channels. The common channels are transmitted with fixed output power. They consume a fixed amount of transmission power resources. It can be seen in the example in Figure 2.43 that the used transmission power recourses for common channels can only take 6 W out of the 20 W total transmission power available in the WBTS. Power Control Algorithms Power control algorithms minimise the transmission power used for dedicated channels. The closed loop power control adjusts the transmission power. Fast Closed Loop Power Control The closed loop power control adjusts the transmission power 1500 times a second to keep the power at the minimum required level. The closed loop power control uses the signal-to-interference ratio (SIR) to adjust the transmission power. It measures the SIR independently for each connection and adjusts the transmission power an every timeslot basis. The measured SIR is compared with the SIR target. If the target is not reached the transmission power is increased; otherwise the transmission power is decreased. In the downlink direction all the NodeBs participating with the SHO connection measure their SIR and determine their power control command. They independently adjust their transmission power according to the power control commands (TPC) received from the UE. Radio Network Planning and Optimisation Total power used for common channels: Common channels Power / CPICH Power on/off CPICH 33 dBm 2.00 W 30 dBm -3 dB 1.00 W 30 dBm -3 dB 1.00 W PCCPCH 28 dBm -5 dB 0.63 W SCCPCH 33 dBm 2.00 W 25 dBm -8 dB 0.32 W 25 dBm -8 dB 0.32 W Total 6.62 W during SCH 38.21 dBm 5.25 W during PCCPCH 37.20 dBm 5.39 W averaged 37.32 dBm Figure 2.43 Total power used for CCHs To determine the power contr