5G • RAN
SIB1
System Information Block 1 (RMSI)
Remaining Minimum System Information (RMSI) defining cell selection parameters, PLMN IDs, and RACH initial configuration.
Technical Explanation
Transmitted on PDSCH and scheduled via PDCCH using SI-RNTI, SIB1 contains fundamental parameters required for a UE to access the cell: PLMN identities, Tracking Area Code (TAC), Cell Identity, Cell Selection Info (Qrxlevmin, Qqualmin), servingCellConfigCommon, and scheduling info for other SIBs.
Key Functions
- Broadcasts PLMN list, TAC, and 36-bit Cell Identity
- Provides S-criterion thresholds for cell selection (Qrxlevmin, Qqualmin)
- Configures common PRACH parameters (preambles, time/frequency occasions)
- Defines scheduling windows and periodicities for OSI (SIB2-SIB9)
Specifications
3GPP TS 38.331, TS 38.213
Interfaces
Uu
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