MIB
MIB is an RRC message of 3GPP TS 38.331 (38331), the 5G NR Radio Resource Control (RRC) protocol.
Definition
The MIB includes the system information transmitted on BCH.
MIB ::= SEQUENCE {
systemFrameNumber BIT STRING (SIZE (6)),
subCarrierSpacingCommon ENUMERATED {scs15or60, scs30or120},
ssb-SubcarrierOffset INTEGER (0..15),
dmrs-TypeA-Position ENUMERATED {pos2, pos3},
pdcch-ConfigSIB1 PDCCH-ConfigSIB1,
cellBarred ENUMERATED {barred, notBarred},
intraFreqReselection ENUMERATED {allowed, notAllowed},
spare BIT STRING (SIZE (1))
}Candidate change requests of v15.3.0
The CRs whose title or cover names this change, strong and likely matches only.
- CR 0100 r4 (likely): Introduction of SA
Fields (8)
| Field | Description |
|---|---|
| systemFrameNumber BIT STRING (SIZE (6)) | The 6 most significant bits (MSB) of the 10-bit System Frame Number (SFN). The 4 LSB of the SFN are conveyed in the PBCH transport block as part of channel coding (i.e. outside the MIB encoding), as defined in clause 7.1 in TS 38.212 [17]. |
| subCarrierSpacingCommon ENUMERATED {scs15or60, scs30or120} | Subcarrier spacing for SIB1 , Msg.2/4 and MsgB for initial access, paging and broadcast SI-messages. If the UE acquires this MIB on an FR1 carrier frequency, the value scs15or60 corresponds to 15 kHz and the value scs30or120 corresponds to 30 kHz. If the UE acquires this MIB on an FR2 carrier frequency, the value scs15or60 corresponds to 60 kHz and the value scs30or120 corresponds to 120 kHz. For operation with shared spectrum channel access in FR1 (see 37.213 [48]) and for operation in FR2-2, the subcarrier spacing for SIB1 , Msg.2/4 and MsgB for initial access, paging and broadcast SI-messages is same as that for the corresponding SSB. For operation with shared spectrum channel access, this field instead is used for deriving the QCL relation between SS/PBCH blocks as specified in TS 38.213 [13], clause 4.1. |
| ssb-SubcarrierOffset INTEGER (0..15) since v15.1.0 | Corresponds to kSSB (see TS 38.213 [13]), which is the frequency domain offset between SSB and the overall resource block grid in number of subcarriers. (See TS 38.211 [16], clause 7.4.3.1). For operation with shared spectrum channel access in FR1 (see 37.213 [48]), this field corresponds to $\overline{k}_{\text{SSB}}$ , and kSSB is obtained from $\overline{k}_{\text{SSB}}$ (see TS 38.211 [16], clause 7.4.3.1); the LSB of this field is used also for deriving the QCL relation between SS/PBCH blocks as specified in TS 38.213 [13], clause 4.1. The value range of this field may be extended by an additional most significant bit encoded within PBCH as specified in TS 38.213 [13]. This field may indicate that this cell does not provide SIB1 and that there is hence no CORESET#0 configured in MIB (see TS 38.213 [13], clause 13). In this case, the field pdcch-ConfigSIB1 may indicate the frequency positions where the UE may (not) find a SS/PBCH with a control resource set and search space for SIB1 (see TS 38.213 [13], clause 13). |
| dmrs-TypeA-Position ENUMERATED {pos2, pos3} | Position of (first) DM-RS for downlink (see TS 38.211 [16], clause 7.4.1.1.2) and uplink (see TS 38.211 [16], clause 6.4.1.1.3). |
| pdcch-ConfigSIB1 PDCCH-ConfigSIB1 since v15.1.0 | Determines a common ControlResourceSet (CORESET), a common search space and necessary PDCCH parameters. If the field ssb-SubcarrierOffset indicates that SIB1 is absent, the field pdcch-ConfigSIB1 indicates the frequency positions where the UE may find SS/PBCH block with SIB1 or the frequency range where the network does not provide SS/PBCH block with SIB1 (see TS 38.213 [13], clause 13). |
| cellBarred ENUMERATED {barred, notBarred} | Value barred means that the cell is barred, as defined in TS 38.304 [20]. This field is ignored by IAB-MT and NCR-MT. This field is ignored for connectivity to NTN or ATG. |
| intraFreqReselection ENUMERATED {allowed, notAllowed} | Controls cell selection/reselection to intra-frequency cells when the highest ranked cell is barred, or treated as barred by the UE, as specified in TS 38.304 [20]. This field is ignored by IAB-MT, NCR-MT and (e)RedCap UE. |
| spare BIT STRING (SIZE (1)) |