SIB4

RRC IE · TS 38.331 v19.4.0 (2026-09) · clause 6.3.1

SIB4 is an RRC information element of 3GPP TS 38.331 (38331), the 5G NR Radio Resource Control (RRC) protocol.

First seen v15.3.0 (2018-09) · Last changed v19.0.0 (2025-10)

Definition

SIB4 contains information relevant for inter-frequency cell re-selection (i.e. information about other NR frequencies and inter-frequency neighbouring cells relevant for cell re-selection), which can also be used for NR idle/inactive measurements. The IE includes cell re-selection parameters common for a frequency as well as cell specific re-selection parameters.

SIB4 ::=                            SEQUENCE {
    interFreqCarrierFreqList            InterFreqCarrierFreqList,
    lateNonCriticalExtension            OCTET STRING                                OPTIONAL,
    ...,
    [[
        interFreqCarrierFreqList-v1610      InterFreqCarrierFreqList-v1610              OPTIONAL   -- Need R
    ]],
    [[
        interFreqCarrierFreqList-v1700      InterFreqCarrierFreqList-v1700              OPTIONAL   -- Need R
    ]],
    [[
        interFreqCarrierFreqList-v1720      InterFreqCarrierFreqList-v1720              OPTIONAL   -- Need R
    ]],
    [[
        interFreqCarrierFreqList-v1730      InterFreqCarrierFreqList-v1730              OPTIONAL   -- Need R
    ]],
    [[
        interFreqCarrierFreqList-v1760      InterFreqCarrierFreqList-v1760              OPTIONAL   -- Need R
    ]],
    [[
        interFreqCarrierFreqList-v1800      InterFreqCarrierFreqList-v1800              OPTIONAL   -- Need R
    ]],
    [[
        interFreqCarrierFreqList-v1900      InterFreqCarrierFreqList-v1900              OPTIONAL   -- Need R
    ]]
}

Candidate change requests of v19.0.0

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

• CR 5389 r2 (likely): Introduction of less than 5MHz in NTN

Fields (9)

Used by (1)

• SystemInformation-IEs

Uses (8)

• InterFreqCarrierFreqList
• InterFreqCarrierFreqList-v1610
• InterFreqCarrierFreqList-v1700
• InterFreqCarrierFreqList-v1720
• InterFreqCarrierFreqList-v1730
• InterFreqCarrierFreqList-v1760
• InterFreqCarrierFreqList-v1800
• InterFreqCarrierFreqList-v1900

In the viewer

• Read SIB4 in v19.4.0
• History of SIB4 across versions
• All versions of TS 38.331
• ASN.1 index