NonCellDefiningSSB (NonCellDefiningSSB-r17)

RRC IE · TS 38.331 v19.4.0 (2026-09) · clause 6.3.2

NonCellDefiningSSB-r17 is an RRC information element of 3GPP TS 38.331 (38331), the 5G NR Radio Resource Control (RRC) protocol.

First seen v17.0.0 (2022-04) · Last changed v17.2.0 (2022-10)

Definition

The IE NonCellDefiningSSB is used to configure a NCD-SSB to be used while the UE operates in an RedCap-specific initial BWP that does not contain the CD-SSB or a dedicated BWP that does not contain the CD-SSB.

NonCellDefiningSSB-r17 ::=      SEQUENCE {
    absoluteFrequencySSB-r17        ARFCN-ValueNR,
    ssb-Periodicity-r17             ENUMERATED { ms5, ms10, ms20, ms40, ms80, ms160, spare2, spare1 }       OPTIONAL,   -- Need S
    ssb-TimeOffset-r17              ENUMERATED { ms5, ms10, ms15, ms20, ms40, ms80, spare2, spare1 }      OPTIONAL,   -- Need S
    ...
}

Candidate change requests of v17.2.0

The CRs whose title or cover names this change, strong and likely matches only.

CR 3400 r1 (strong): Miscellaneous corrections for RedCap WI

Fields (3)

Field	Description
absoluteFrequencySSB-r17 ARFCN-ValueNR	Frequency of the NCD-SSB. The network configures this field so that the SSB is within the bandwidth of the BWP configured in BWP-DownlinkCommon .
ssb-Periodicity-r17 ENUMERATED { ms5, ms10, ms20, ms40, ms80, ms160, spare2, spare1 } · OPTIONAL Need S since v17.1.0	The periodicity of this NCD-SSB. The network configures only periodicities that are larger than the periodicity of serving cell's CD-SSB. If the field is absent, the UE applies the SSB periodicity of the CD-SSB ( ssb-periodicityServingCell configured in ServingCellConfigCommon or ServingCellConfigCommonSIB ).
ssb-TimeOffset-r17 ENUMERATED { ms5, ms10, ms15, ms20, ms40, ms80, spare2, spare1 } · OPTIONAL Need S since v17.1.0	The time offset between CD-SSB of the serving cell and this NCD-SSB. Value ms5 means the first burst of NCD-SSB is transmitted 5ms later than the first burst of CD-SSB transmitted after the first symbol of SFN=0 of the serving cell, value ms10 means the first burst of NCD-SSB is transmitted 10ms later than the first burst of CD-SSB transmitted after the first symbol in SFN=0 of the serving cell, and so on. If the field is absent, UE considers that the time offset between the first burst of CD-SSB transmitted in the serving cell and the first burst of this NCD-SSB transmitted is zero. For UEs in TDD cells, the network configures this time offset to be an integer multiple of the periodicity of the serving cell's CD-SSB.

Used by (2)

Uses (1)

ARFCN-ValueNR