ening are used depending on the code rate. When the code rate is lower than or equal to 7/16, puncturing is used, whereas shortening is used for other rates. A bit interleaver is only applied to the UL control channel. The interleaver is known as the triangular interleaver, where the write-read operation is similar to traditional block interleaving. 6.14 Dual Connectivity The use of dual connectivity with either LTE or another 5G carrier is an essential part of 5G operation. The very first wave of 5G devices need to support the dual connectiv- ity operation between LTE and 5G. This requires some extra considerations, especially for the resource sharing between the two uplink transmissions. The dual connectivity between 5G and LTE does not assume tight coordination between the eNB and gNB. Also, co-siting is not required for dual connectivity operation, unlike with traditional carrier aggregation. Dual connectivity was also introduced in LTE Release 12, but dual connectivity was not deployed in real networks and is not supported on the UE side. The challenge was the requirement of two independent transmitters and receivers, as only a limited set of UEs supported uplink carrier aggregation even if the uplink throughput had clearly improved. The key element is the uplink power sharing between LTE and 5G. If the power sharing is semi-static, this would mean that even if, for example, LTE would not be transmit- ting anything, the UE would reserve part of the transmission power for the LTE side, 6.14 Dual Connectivity thus reducing coverage for the 5G side. With dynamic power sharing, the 5G uplink transmission power is reduced only momentarily if transmission power is really needed on the LTE side. The uplink power control was addressed in further detail in Section 6.11. Release 15 (part of the late drop) also includes 5G-5G dual connectivity, which assumed synchronization between different gNBs. This was necessary to limit the impact to the uplink power control, as the uplink frame timing has some alignment between t