tics of the MIB message support and SIB messages. RLC mode Logical channel Transport channel Physical channel No object Master Information Block No object DL-SCH PDSCH System Information Block Table 9.1. Support of message relating to system information NG-RAN and 5G-NR: 5G Radio Access Network and Radio Interface, First Edition. Frédéric Launay. C ISTE Ltd 2021. Published by ISTE Ltd and John Wiley & Sons, Inc. 238 NG-RAN and 5G-NR The BCCH logical channel transports MIB information on 24 bits. The PBCH physical channel adds an additional 8 bits of payload (PBCH Payload). Generation of the PBCH data is therefore composed of a 24-bit block from the BCH channel, then 8 bits and the 24-bit CRC code (Figure 9.1). The payload of the PBCH contains: - 4 least significant bits completing the frame number transmitted in the MIB message; - 3 bits for (depending on the number of SSB (synchronization signal block) bursts): - the index of the synchronization signal block (SSB Index) for beam sweeping of 64 bursts (FR2), - or 1 most significant bit for the offset of the SSB block (Kssb) and 2 bits not used in the specification of Release 16; - 1 bit indicating the half-frame. Bit half-frame SSB Index CRC (24 bits) Bits SFN Figure 9.1. PBCH physical channel. For a color version of this figure, see www.iste.co.uk/launay/5g.zip The SI-RNTI (System Information - Radio Network Temporary Identifier) is used to retrieve the description of the resource assigned to SIB messages in the PDSCH (Physical Downlink Shared Channel). This description is provided by the PDCCH (Physical Downlink Shared Channel). 9.1.1. MIB message The MIB message is transmitted in the synchronization signal block. 5G-NR Radio Interface - Radio Access Procedure The MIB provides the information needed by the mobile to read the PDCCH. During this step, the information carried by the PDCCH only makes it possible to read the SIB1 message. The MIB message contains the following parameters: MasterInformationBlock systemFrameNumber subCarrierSpacingCommon ssb-Subcarrie