hile otherwise aspects are mostly in place. The 5G-5G dual connectivity example is shown in Figure 15.9. The other elements cover early measurement reporting to reduce setup delay for the dual connection or carrier aggregation operation, fast serving cell activation with min- imized signaling, and fast recovery from Master Cell Group (MCG) failure when using dual connectivity. The work is scheduled to be finalized by the end of Release 16 by March 2020. 15.2.8 Two-Step RACH The work on two-step RACH was motived by reducing the delay associated with the random access procedure. While the reduction in the number of steps necessitates more resources for the initial RACH transmission (the preamble alone is not sufficient), the benefit comes especially from reduced latency, in particular, with 5G-U, when one can avoid further LBT instances when all necessary information is sent in one go. The Release 15 RACH operation (four-step RACH) is compared to the two-step RACH in Figure 15.10. The example assumes contention-based RACH operation. 15.2.9 UE Power Consumption Reduction UE power consumption has generally always been a challenge when a new system is introduced. With 5G there are aspects (such as those discussed in Chapters 12 and 13) stemming from support of large data rates as well as large bandwidths together with multiple receiver branches which contribute to the power consumption. The use of dual connectivity with LTE does not help the situation from the power consumption point of view. The study will look into further considerations regarding UE power reduction, with the key principle being to limit the necessary processing a UE has to perform when there is no data transmission actually going or when the required data rate is small. The key principles such as bandwidth part already exist in the Release 15 specifications as well as basic discontinuous reception procedures. 5G UE 5G gNB 5G UE 5G gNB 1. Preamble 1. Preamble & message 2. RA Response 3. Scheduled Transmission 2. Response 4. Contention Resolution 4-s