5G NR MIB and its Example

[alhamdisyukra]

The Master Information Block (MIB) is transmitted using the BCCH logical channel, the BCH transport channel and the PBCH physical channel. The MIB provides the UE with information regarding the Control Resource Set (CORESET) and Search Space used by the PDCCH when making a resource allocation for SIB 1.
The characteristic of MIB:
∙ Transmitted with the periodicity of 80 ms and within this 80 ms repeatative transmission happens
∙ For initial cell selection, a UE may assume that half frames with SS/PBCH blocks occur with a periodicity of 2 frames
∙ Includes the parameters that are required to decode SIB1 (SystemInformationType1)

The structure of SIB is
MIB ::= SEQUENCE {
systemFrameNumber BIT STRING (SIZE (6)),
subCarrierSpacingCommon ENUMERATED {scs15or60, scs30or120},
ssb-SubcarrierOffset INTEGER (0..15),
dmrs-TypeA-Position (https://www.sharetechnote.com/html/5G/5G_PDSCH_DMRS.html) ENUMERATED {pos2, pos3},
pdcch-ConfigSIB1 INTEGER (0..255),
cellBarred ENUMERATED {barred, notBarred},
intraFreqReselection ENUMERATED {allowed, notAllowed},
spare BIT STRING (SIZE (1))
}


Example:
101681 08:08:22.511 NR 5G RRC OTA Message BCCH-BCH MIB
Ver.: 9, NR RRC Rel.: 15.9.0, NR ARFCN: 361730, NR PCI: 88
NR_Uu_RRC: BCCH_BCH_Message
- . .message:- mib
- . . . .systemFrameNumber: 58
- . . . .subCarrierSpacingCommon: 0 ( scs15or60)
- . . . .ssb-SubcarrierOffset: 15
- . . . .dmrs-TypeA-Position: 1 ( pos3)
- . . . .pdcch-ConfigSIB1
- . . . . .controlResourceSetZero: 11
- . . . . .searchSpaceZero: 2
- . . . .cellBarred: 1 ( notBarred)
- . . . .intraFreqReselection: 0 ( allowed)
- . . . .spare: 0

References: 5G NR in Bullets, Sharetechnote