ranularity of channel occupation in the time domain. In addition, the processing delay for the short symbol demodulation is reduced, SO retransmission for short symbols in the same MCOT becomes possible and HARQ combining gain can be achieved with low latency. Furthermore, the overhead of guard band with 60 kHz SCS wideband carrier is also smaller than that of LTE-based LAA. However, in carrier aggrega- tion scenarios, the performance gain of 60 kHz SCS relative to LTE-based LAA diminishes because of the spectrum efficiency loss from guard bands in 60 kHz SCS and 20 MHz band- width. The occupied channel bandwidth of an SS/PBCH block with subcarrier spacing 15 and 30 kHz is 3.6 and 7.2 MHz, respectively. An SS/PBCH block with subcarrier spacing 15 kHz in 5 GHz unlicensed band cannot meet the OCB requirements because system/nomi- nal bandwidth in most cases would be greater than 5 MHz. The NR-U should support simi- lar SCS in 6-7 GHz unlicensed bands. To support 60 kHz SCS for all NR-U signaling in operation below 6 GHz, some modifications in Rel-15 NR are required because NR does not support SS/PBCH block transmission using 60 kHz. In addition, the candidate SS/PBCH positions for a half frame are not defined for 60 kHz SCS. Note that the use of 60 kHz SCS for PRACH transmission in NR is also restricted to frequencies above 6 GHz. For outdoor deployments, even if the output power is limited, considerable delay spread can still be observed. For 60 kHz SCS with normal CP, the cyclic prefix is 1.17 us corresponding to a range of 175.5 m, which is very typical in outdoor environments. The cyclic prefix of 60 kHz SCS with extended CP is 4.17 us corresponding to a range of 625.5 m, which would be sufficient for most outdoor small cell deployments. In NR, the SCS for each channel or signal is configured through the BWP information ele- ment (IE) configuration, and the subcarrier spacing in the BWP IE is used for all channels and reference signals unless explicitly configured. The reference SCS of the slot structure config