LTE RRC InDeviceCoex Indication 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	Coexistence Reporting

Full message name	LTE RRC InDeviceCoex Indication r11
Protocol	LTE-RRC
Technology	LTE
Direction	UE -> eNodeB
Interface	Uu
Signaling bearer / channel	SRB1 / UL-DCCH
Typical trigger	Triggered when the UE detects in-device coexistence constraints affecting LTE operation.
Main purpose	Lets the UE inform the eNodeB that another radio or internal coexistence condition is constraining LTE behavior so the network can adapt scheduling or configuration.
Main specification	3GPP TS 36.331, 5.6, 6.2.2
Release added	Release 11
Procedures where used	In-device coexistence reporting

What is LTE RRC InDeviceCoex Indication r11 in simple terms?

Uplink LTE RRC message used by the UE to report in-device coexistence constraints that affect LTE radio operation.

Lets the UE inform the eNodeB that another radio or internal coexistence condition is constraining LTE behavior so the network can adapt scheduling or configuration.

Why this message matters

InDeviceCoex Indication r11 tells the LTE network that another internal radio or coexistence condition is constraining LTE behavior.

Where this message appears in the call flow

In-device coexistence reporting

LTE flow showing InDeviceCoex Indication r11 sent to report a coexistence constraint — The UE reports a coexistence-related constraint so the eNodeB can treat the issue as an in-device coexistence problem rather than only a radio-quality event.

Call flow position: UE report sent when another internal radio or coexistence condition affects LTE operation.

Typical state: The network can use the report to reduce interference impact or adapt later configuration.

Preconditions:

The UE is in connected mode.
The UE has detected a coexistence-related issue or constraint.

Next likely message: Later coexistence-aware reconfiguration or scheduling adjustment

Coexistence recovery update

LTE flow showing InDeviceCoex Indication r11 used as an updated coexistence status report — A later coexistence update can help the network understand whether the coexistence condition is still active or has changed.

Call flow position: UE update sent when the coexistence condition changes and the network needs refreshed context.

Typical state: The report helps the eNodeB distinguish a radio coexistence issue from pure LTE radio degradation.

Preconditions:

A coexistence condition exists or has recently changed.

Next likely message: Connected-mode continuation with updated coexistence handling

Call flow position

Previous message(s): RRCConnectionReconfiguration

Next message(s): Network coexistence handling, RRCConnectionReconfiguration

Message direction and transport

Sender and receiver: UE -> eNodeB

Interface: Uu

Domain: Access-side radio control with coexistence reporting

Signaling bearer: SRB1

Logical channel: UL-DCCH

Transport / encapsulation: Protected LTE RRC signaling in connected mode

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

Message Structure Overview

InDeviceCoexIndication-r11 is a UE-originated report about internal coexistence constraints.
The important read is what coexistence condition exists and what carrier context is affected.

ASN.1 for LTE RRC InDeviceCoex Indication r11

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

How to read this ASN.1

Treat this message as a coexistence report that explains why the UE may need network-side mitigation.

LTE RRC InDeviceCoex Indication r11 - Example Dump

UL-DCCH-Message
  message c1 : inDeviceCoexIndication-r11 : {
    criticalExtensions c1 : inDeviceCoexIndication-r11 : {
      affectedCarrierFreqList-r11 present
    }
  }

How to read this dump

The value is in the coexistence context, not in the wrapper.

Important Information Elements

IE	Required	Description
`criticalExtensions`	Yes	Carries the InDeviceCoexIndication-r11 branch.
`affectedCarrierFreqList-r11`	Optional	Identifies LTE frequencies affected by the coexistence condition.

Detailed field explanation

`criticalExtensions`

Carries the InDeviceCoexIndication-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.

`affectedCarrierFreqList-r11`

Identifies LTE frequencies affected by the coexistence condition.

Presence: Optional

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 carrier or feature was affected.
Compare the message timing with observed UE coexistence symptoms.
Look for later coexistence-aware reconfiguration or scheduling changes.

Common Issues and Troubleshooting

LTE performance degrades only when another in-device radio is active.

Likely cause: The UE may be reporting coexistence constraints through InDeviceCoexIndication-r11.

What to inspect: Check whether the message appeared and what frequencies or coexistence context were indicated.

Next step: Correlate the report with later network mitigation behavior.

FAQ

What is InDeviceCoex Indication r11 in LTE?

It is the uplink LTE RRC message the UE uses to report in-device coexistence constraints that affect LTE operation.

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.