LTE RRC LTE Broadcast 3GPP TS 36.331

LTE RRC System Information BR r13

Broadcast LTE RRC message carrying bandwidth-reduced system information.

Message Fact Sheet

Protocol	lte-rrc	Network	lte
Spec	3GPP TS 36.331	Spec Section	5.2.2, 6.2.2
Direction	Broadcast	Message Type	Broadcast System Information

Full message name	LTE RRC System Information BR r13
Protocol	LTE-RRC
Technology	LTE
Direction	Broadcast
Interface	Uu
Signaling bearer / channel	Broadcast / BCCH-DL-SCH
Typical trigger	Read by the UE after BR-specific broadcast anchoring.
Main purpose	Delivers later BR-specific system information after the UE has already acquired the earlier broadcast anchors.
Main specification	3GPP TS 36.331, 5.2.2, 6.2.2
Release added	Release 13
Procedures where used	BR system information acquisition

What is LTE RRC System Information BR r13 in simple terms?

Broadcast LTE RRC message carrying bandwidth-reduced system information.

Delivers later BR-specific system information after the UE has already acquired the earlier broadcast anchors.

Why this message matters

System Information BR r13 is the later LTE broadcast system-information container for BR-specific operation.

Where this message appears in the call flow

BR system information acquisition

LTE flow showing System Information BR r13 acquired after SIB1-BR — After SIB1-BR, the UE reads System Information BR r13 to continue BR-specific broadcast acquisition.

Call flow position: Later broadcast block read after earlier BR-specific broadcast anchoring.

Typical state: The UE is collecting the BR-specific system information needed for later operation.

Preconditions:

The UE already acquired the earlier BR-specific broadcast anchor.

Next likely message: Later BR-specific idle or access continuation

BR idle-mode information update

LTE flow showing System Information BR r13 refresh during BR idle-mode update — The same message is used when BR-specific later system information needs refreshing.

Call flow position: Broadcast read step used when BR-specific system information needs refreshing.

Typical state: The message updates BR-specific broadcast context rather than dedicated connected-mode state.

Preconditions:

A BR-specific broadcast context exists.

Next likely message: Updated BR-specific continuation

Call flow position

Previous message(s): SystemInformationBlockType1-BR-r13

Next message(s): Later BR-specific idle or access handling

Message direction and transport

Sender and receiver: Broadcast

Interface: Uu

Domain: Access-side broadcast control for BR operation

Signaling bearer: Broadcast

Logical channel: BCCH-DL-SCH

Transport / encapsulation: LTE broadcast system information

Security context: Broadcast information

Message Structure Overview

SystemInformation-BR-r13 is the later BR-specific system-information container.

ASN.1 for LTE RRC System Information BR r13

SystemInformation-BR-r13 ::= SEQUENCE {
  criticalExtensions CHOICE {
    c1 CHOICE {
      systemInformation-BR-r13 SystemInformation-BR-r13-IEs,
      spare3 NULL,
      spare2 NULL,
      spare1 NULL
    },
    criticalExtensionsFuture SEQUENCE {}
  }
}

How to read this ASN.1

Read it as the BR-specific later system-information container.

LTE RRC System Information BR r13 - Example Dump

BCCH-DL-SCH-Message
  message c1 : systemInformation-BR-r13 : present

How to read this dump

The useful read is what BR-specific system-information branch the UE reaches after SIB1-BR.

Important Information Elements

IE	Required	Description
`SystemInformation-BR-r13`	Yes	Carries BR-specific later system information content.

Detailed field explanation

`SystemInformation-BR-r13`

Carries BR-specific later system information content.

Presence: Required

In practice: In practice, compare this field with the original request and with any later release-dependent optional fields so you can see whether the network accepted the same service model the UE asked for.

What to check in logs and traces

Check that SIB1-BR was already acquired.
Compare this message with later BR-specific idle or access handling.

Common Issues and Troubleshooting

The UE acquires the BR anchor but not the later BR system information.

Likely cause: The later BR system-information branch may be missing, stale, or not reacquired.

What to inspect: Check whether System Information BR r13 appears after the earlier BR broadcast anchor.

Next step: Treat it as BR-specific system-information acquisition troubleshooting.

FAQ

What is System Information BR r13 in LTE?

It is the LTE broadcast system-information container used for later BR-specific system information.

Related message pages

Related Procedures

Related Tools

Use This Reference in Practice

Decode this message with the 3GPP Decoder, inspect the related message database, or open the matching call flow to see where this signaling step fits in the full procedure.