RRCSystemInfoRequest

RRC message · TS 38.331 v19.4.0 (2026-09) · clause 6.2.2

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

First seen v15.3.0 (2018-09) · Last changed v16.1.0 (2020-07)

Definition

The RRCSystemInfoRequest message is used to request SI message(s) required by the UE as specified in clause 5.2.2.3.3 and 5.2.2.3.3a.

RRCSystemInfoRequest ::=            SEQUENCE {
    criticalExtensions                  CHOICE {
        rrcSystemInfoRequest                RRCSystemInfoRequest-IEs,
        criticalExtensionsFuture-r16        CHOICE {
            rrcPosSystemInfoRequest-r16         RRC-PosSystemInfoRequest-r16-IEs,
            criticalExtensionsFuture            SEQUENCE {}
        }
    }
}

Fields (5)

Field	Description
criticalExtensions CHOICE {
rrcSystemInfoRequest RRCSystemInfoRequest-IEs since v15.8.0
criticalExtensionsFuture-r16 CHOICE { since v16.1.0
rrcPosSystemInfoRequest-r16 RRC-PosSystemInfoRequest-r16-IEs since v16.1.0
criticalExtensionsFuture SEQUENCE {} since v16.1.0

Fields of RRCSystemInfoRequest-IEs (2)

Field	Description
requested-SI-List BIT STRING (SIZE (maxSI-Message)) since v15.8.0	Contains a list of requested SI messages which are configured by schedulingInfoList in si-SchedulingInfo and schedulingInfoList2 in si-SchedulingInfo-v1700 (if present) in SIB1. If si-SchedulingInfo-v1700 is not present: - According to the order of entry in the list of SI messages configured by schedulingInfoList in si-SchedulingInfo in SIB1 , first bit corresponds to first/leftmost listed SI message, second bit corresponds to second listed SI message, and so on. If si-SchedulingInfo-v1700 is present: - The UE generates a list of concatenated SI messages by appending the SI messages containing type1 SIB configured by schedulingInfoList2 in si-SchedulingInfo-v1700 to the SI messages configured by schedulingInfoList in si-SchedulingInfo . - According to the order of entry in the list of concatenated SI messages, first bit corresponds to first/leftmost listed SI message, second bit corresponds to second listed SI message, and so on.
spare BIT STRING (SIZE (12)) since v15.8.0

Field

Description

requested-SI-List

BIT STRING (SIZE (maxSI-Message))

since v15.8.0

Contains a list of requested SI messages which are configured by schedulingInfoList in si-SchedulingInfo and schedulingInfoList2 in si-SchedulingInfo-v1700 (if present) in SIB1. If si-SchedulingInfo-v1700 is not present: - According to the order of entry in the list of SI messages configured by schedulingInfoList in si-SchedulingInfo in SIB1 , first bit corresponds to first/leftmost listed SI message, second bit corresponds to second listed SI message, and so on. If si-SchedulingInfo-v1700 is present: - The UE generates a list of concatenated SI messages by appending the SI messages containing type1 SIB configured by schedulingInfoList2 in si-SchedulingInfo-v1700 to the SI messages configured by schedulingInfoList in si-SchedulingInfo . - According to the order of entry in the list of concatenated SI messages, first bit corresponds to first/leftmost listed SI message, second bit corresponds to second listed SI message, and so on.

spare

BIT STRING (SIZE (12))

since v15.8.0

Fields of RRC-PosSystemInfoRequest-r16-IEs (2)

Field	Description
requestedPosSI-List BIT STRING (SIZE (maxSI-Message)) since v16.1.0
spare BIT STRING (SIZE (11)) since v16.1.0

Used by (1)

UL-CCCH-MessageType