 terminal measures the timing difference of the SFN and the frame boundary between the serving cell and the Chapter 5 SMTC window=2 ms Actual measurement window=3 ms Measurement gap length=4 ms RF retuning time (no RF retuning time (no data transmission) data transmission) MGRP=20 ms MGL 4 ms MGL=6ms Measurement MGL: Measurement gap length Actual measurement window MGRP: Measurement gap repetition period 15 kHz subcarrier spacing window SMTC window=4 ms Actual measurement window=5 ms Measurement gap length=6 ms RF retuning time (no RF retuning time (no data transmission) data transmission) Figure 5.16 Illustration of the NR measurement gap configuration 29]. candidate cell and reports it to the serving gNB. The observed SFTD between an LTE PCell and an NR PSCell consists of two components as follows [7]: SFN_offset = (SFNPCell - SFNpscell)Moo 1024, where SFNPCell is the SFN of an LTE PCell and SFNPSCell is the SFN of the NR PSCell from which the UE receives the clos- est starting time to the time when it receives the start of the PCell radio frame. Frame_boundary_offset = (T Frame_Boundary_PCell - /5 , where Frame_Boundary_PCell is the time when the UE receives the start of a radio frame from the PCell, is the time when the UE receives the start of the radio frame, from the PSCell, that is closest in time to the radio frame received from the PCell. The unit of (TFrame__Boundary__PCel I Frame_Boundary_PSCeI1 is the NR sampling time. The BS configures SFTD measurements for an NR UE neighbor cells. For a terminal to per- form SFTD measurements on neighboring cells to which it is not connected, measurement gaps are required. However, if the serving gNB does not know the SSB transmission timing New Radio Access RF and Transceiver Design Considerations Table 5.14: NR measurement gap pattern configurations [6]. Gap Pattern ID Measurement Gap Length (ms) Measurement Gap Repetition Period (ms) UE cannot detect the first SSB since it is overlapping with RF retuning time SMTC window=5 ms RF retuning time (no Actual measurem