ia broadcast SI or UE- specific RRC signaling depending on whether it is a common CORESET or UE-specific CORESET. Compared to LTE PDCCH, the configurability of the CORESETs enable effi- cient resource sharing between downlink control and shared channels, thereby allowing efficient layer-1 signaling overhead management. One of the factors which could impact Chapter 4 PDCCH aggregation level 2 PDCCH REIRE ERERERE One-symbol CORESET REG10 REG11 REG12 REG13 REG14 REG15 REG16 REG17 Two-symbol CORESET REG10 REG12 REG14 REG16 REG18 REG20 REG22 REG24 REG26 REG28 REG30 REG32 REG34 REG11 REG13 REG15 REG17 REG19 REG21 REG23 REG25 REG27 REG29 REG31 REG33 REG35 REG bundle One-symbol CORESET, bundling size 2 REG10 REG11 REG12 REG13 REG14 REG15 REG16 REG17 REG Bundle Two-symbol CORESET, bundling size 2 REG10 REG12 REG14 REG16 REG18 REG20 REG22 REG24 REG26 REG28 REG30 REG32 REG34 REG11 REG13 REG15 REG17 REG19 REG21 REG23 REG25 REG27 REG29 REG31 REG33 REG35 REG bundle Two-symbol CORESET, bundling size 6 REG10 REG12 REG14 REG16 REG18 REG20 REG22 REG24 REG26 REG28 REG30 REG32 REG34 REG11 REG13 REG15 REG17 REG19 REG21 REG23 REG25 REG27 REG29 REG31 REG33 REG35 Frequency Figure 4.14 Illustration of RE, REG, CCE, REG bundle, and CORESET and example mappings of CCE to REG Bundles 14,68]. the time-domain duration of a CORESET is the bandwidth of the corresponding carrier, where more control symbols may be allowed for smaller bandwidths. For example, assum- ing a CORESET consists of 48 PRBs with 2 OFDM symbols, there are 16 CCEs that could accommodate up to 2 PDCCH candidates at AL-8 or a single candidate at AL-16. Furthermore, there can be multiple CORESETs inside the system bandwidth; thus the CORESET may not fully occupy the system bandwidth in the frequency domain. Downlink power adjustment can be applied to CORESETs that occupy narrower fre- quency regions within the carrier bandwidth, depending on desired coverage and link New Radio Access Physical Layer Aspects (Part 2) 443 budget. In that case, one or two OFDM symbols may not be s