< 24.5 GHz N=0:14756 24250.08 MHz +N*17.28 f > 24.5 GHz 22256+N 17.28 MHz N=0:4383 Table 6.7. Frequency search configuration Once synchronized (i.e. centered on the GSCN frequency), the mobile is able to determine the frequency position of subcarrier 0 of the SSB. However, the SSB block must be positioned in a grid of channels spaced 15 kHz apart. The frequency location of an SSB may not be aligned to a PRB. The base station sends information in the MIB message (see Chapter 9) allowing the mobile to know the frequency offset between subcarrier 0 of the SSB block and subcarrier 0 of the PRB block. This frequency offset is determined by the Kssb parameter. For the FR1 band, the frequency difference is equal to 15 kHz * Kssb, the value of 15 kHz being the measurement reference. In the case where the spacing between subcarriers is 15 kHz, the Kssh value is between 0 and 11. In the case where the spacing between subcarriers is 30 kHz, the Kssb value is between 0 and 23. For the FR2 band, the frequency deviation is equal to 120 kHz * Kssb. An additional offset also transmitted in the MIB information message allows the mobile to know the start of the active BWP band. 5G-NR Radio Interface - MIMO and Beamforming offset Initial active DL BWP Figure 6.16. SSB position relative to PRB In standby mode, the cell re-selection procedure allows the mobile to select a more suitable cell and to camp on it. When the base station broadcasts several SSB (beam-sweeping), the mobile measures each SSB. An SSB is identified by an index. The mobile selects the beam on which it can camp and whose reception power is the highest. 6.6.3. Beam management When the mobile wants to establish a radio connection, it begins by sending a random access request, as described in Figure 3.7: - the mobile UE selects the best SSB beam; - the mobile UE transmits the random access request in message 1 carrying the preamble; - the mobile UE optionally repeats the same by increasing the power to the selected beam or to different beams (UE beam sweeping); - the