, 50%, 56%, 63%, 70%, 80%, 90%, 95% and 100%. The configuration where UE power resources are simply divided between MCG and SCG (i.e. P_MeNB + P_SeNB = 100%) can be easily done. It is also possible to make a configuration where P_MeNB + P_SeNB < 100%. In this case, there is remaining power that is not dedicated to certain cell group and this remaining power can be dynamically allocated to MCG or SCG depending on scheduling. After the uplink power is allocated to MCG and SCG, Release 11 power scaling and channel dropping rules are applied within the cell group. It should be noted that guaranteed powers and remaining power allocation are applicable to PUCCH, PUSCH and SRS transmissions but PRACH can use all the UE power, if needed. Dual connectivity can be used both in synchronous and asynchronous networks. Two power control modes have been defined for dual connectivity: PCM1 (power control mode1) is used in synchronous and PCM2 in asynchronous networks. All the dual connectivity capable UEs must support PCM1. If UE supports both power control modes, eNB configures the power control mode to be used by the UE. In the Figure 4.8, power control mode 1 is depicted. The priority order for allocating the remaining power to MCG and/or SCG transmissions is based on UCI type. The priority order is the following: HARQ/ACK = SR > CSI > PUSCH without UCI > SRS. If same type of UCI transmission takes place simultaneously in MCG and SCG, MCG transmission is prioritized. If less than the guaranteed power is required for transmission to one of the cell groups, unused power can be used in the other cell group. The allocation of remaining power is done separately to the SRS symbol. If network is not synchronous, eNodeB configures PCM2 for the UEs. In the asynchronous case, sub-frame boundaries are not aligned between transmissions to MeNodeB and SeNodeB, as can be seen in Figure 4.9. In the standard it has been assumed that UE is not fast enough PUSCH/PUCCH MeNB PUSCH/PUCCH SeNB Figure 4.9 Asynchronous operation LTE Small Cell Optim