LTE RRC UE Assistance Information r11

Message Fact Sheet

Protocol	lte-rrc	Network	lte
Spec	3GPP TS 36.331	Spec Section	5.6, 6.2.2
Direction	UE -> eNodeB	Message Type	UE Assistance / Optimization

Full message name	LTE RRC UE Assistance Information r11
Protocol	LTE-RRC
Technology	LTE
Direction	UE -> eNodeB
Interface	Uu
Signaling bearer / channel	SRB1 / UL-DCCH
Typical trigger	Triggered when the UE needs to provide assistance information relevant to connected-mode handling.
Main purpose	Lets the UE report assistance-related context such as power-preference or traffic-handling hints so the eNodeB can adapt later connected-mode behavior.
Main specification	3GPP TS 36.331, 5.6, 6.2.2
Release added	Release 11
Procedures where used	UE assistance reporting, Connected-mode optimization

What is LTE RRC UE Assistance Information r11 in simple terms?

Uplink LTE RRC message used by the UE to provide assistance information the network can use for connected-mode optimization decisions.

Lets the UE report assistance-related context such as power-preference or traffic-handling hints so the eNodeB can adapt later connected-mode behavior.

Why this message matters

UE Assistance Information r11 is the UE telling the LTE network about assistance-related context that may influence later handling.

Where this message appears in the call flow

Connected-mode UE assistance reporting

LTE flow showing UE Assistance Information r11 sent during connected-mode optimization reporting — UE Assistance Information r11 is sent from the UE while connected so the eNodeB can use the reported assistance context in later optimization decisions.

Call flow position: UE-side assistance message sent while the UE is already in connected mode.

Typical state: The network can use the reported assistance information for later scheduling or configuration choices.

Preconditions:

The UE is in RRC_CONNECTED.
The UE has assistance information worth reporting.

Next likely message: Later RRCConnectionReconfiguration or connected-mode continuation

Power or traffic preference update

LTE flow showing UE Assistance Information r11 used for later preference-aware optimization — The message is often best read as a preference or assistance update that influences later network-side handling rather than an immediate control command.

Call flow position: Optimization-oriented report sent when the UE wants the network to take updated assistance context into account.

Typical state: The report itself does not change configuration immediately, but it influences later network-side decisions.

Preconditions:

The UE has updated assistance information.

Next likely message: Network optimization handling

Call flow position

Previous message(s): RRCConnectionReconfiguration, Connected-mode signaling before optimization reporting

Next message(s): Later connected-mode optimization, RRCConnectionReconfiguration

Message direction and transport

Sender and receiver: UE -> eNodeB

Interface: Uu

Domain: Access-side radio control optimization

Signaling bearer: SRB1

Logical channel: UL-DCCH

Transport / encapsulation: Protected LTE RRC signaling in connected mode

Security context: Sent after LTE AS security activation as protected connected-mode signaling.

Message Structure Overview

UEAssistanceInformation-r11 is an uplink optimization-oriented LTE RRC message.
The useful read is the presence and timing of the assistance payload and what network action follows later.

ASN.1 for LTE RRC UE Assistance Information r11

UEAssistanceInformation-r11 ::= SEQUENCE {
  criticalExtensions CHOICE {
    c1 CHOICE {
      ueAssistanceInformation-r11 UEAssistanceInformation-r11-IEs,
      spare3 NULL,
      spare2 NULL,
      spare1 NULL
    },
    criticalExtensionsFuture SEQUENCE {}
  }
}

How to read this ASN.1

Read this message as a UE-to-network optimization hint rather than a mobility command.

LTE RRC UE Assistance Information r11 - Example Dump

UL-DCCH-Message
  message c1 : ueAssistanceInformation-r11 : {
    criticalExtensions c1 : ueAssistanceInformation-r11 : {
      ue-AssistanceInformation-r11 present
    }
  }

How to read this dump

The inner assistance payload matters more than the wrapper itself.

Important Information Elements

IE	Required	Description
`criticalExtensions`	Yes	Carries the release-specific UEAssistanceInformation-r11 branch.
`ue-AssistanceInformation-r11`	Yes	Main information element containing the UE assistance payload.

Detailed field explanation

`criticalExtensions`

Carries the release-specific UEAssistanceInformation-r11 branch.

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.

`ue-AssistanceInformation-r11`

Main information element containing the UE assistance payload.

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 what assistance information the UE actually reported.
Correlate the message with later optimization or reconfiguration behavior.
Do not treat the message itself as a failure or mobility event.

Common Issues and Troubleshooting

The network does not seem to react to UE-side assistance or preference information.

Likely cause: The UE may not have sent UE Assistance Information r11, or the network may not have used it.

What to inspect: Check the presence and timing of the message and what later connected-mode action followed.

Next step: Compare the report with later reconfiguration or scheduling behavior.

FAQ

What is UE Assistance Information r11 in LTE?

It is the uplink LTE RRC message the UE uses to report assistance information that can help the network optimize connected-mode handling.

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.