| Protocol | rrc | Network | 5g |
|---|---|---|---|
| Spec | 3GPP TS 38.331 | Spec Section | 6.2.2 |
| Direction | gNB -> UE | Message Type | Mobility Control |
| Full message name | 5G NR - Mobility From NR Command |
|---|---|
| Protocol | RRC |
| Technology | 5G |
| Direction | gNB -> UE |
| Interface | Uu |
| Signaling bearer / channel | SRB1 / DL-DCCH |
| Typical trigger | Used when the network commands the UE to move away from the current NR serving context. |
| Main purpose | Carries the mobility command and target-related information needed when the UE must move away from the current NR radio context. |
| Main specification | 3GPP TS 38.331, 6.2.2 |
| Release added | Release 15 |
| Procedures where used | Inter-RAT Mobility, Mobility from NR |
Mobility From NR Command is the NR RRC message used by the network to command mobility away from the current NR context toward another target system or mobility outcome.
Carries the mobility command and target-related information needed when the UE must move away from the current NR radio context.
Mobility From NR Command tells the UE to move away from the current NR serving setup.
Call flow position: Sent as the actual mobility command after the network has made the mobility decision.
Typical state: UE is in connected mode and is being moved away from the current NR configuration.
Preconditions:
Next likely message: Target-system access or release handling
Previous message(s): Measurement Report, RRC Reconfiguration
Next message(s): Target RAT / frequency access, Release or handover completion outside NR
Security context: Sent as protected connected-mode signaling.
MobilityFromNRCommand ::= SEQUENCE {
criticalExtensions CHOICE {
mobilityFromNRCommand MobilityFromNRCommand-IEs,
...
}
}
Engineers read this message by identifying the target mobility action and then correlating it with the following target-access behavior.
DL-DCCH-Message
message: mobilityFromNRCommand
targetRAT-Message: present
| IE | Required | Description |
|---|---|---|
targetRAT-Message | Optional | Carries target-system information or command content. |
mobilityControlInfo | Optional | Encodes the mobility instruction the UE must follow. |
targetRAT-MessageCarries target-system information or command content.
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.
mobilityControlInfoEncodes the mobility instruction the UE must follow.
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.
Likely cause: The target command may be wrong, incomplete, or not applied correctly.
What to inspect: Check the target RAT or mobility information carried in the command.
Next step: Follow the target-access trace after the command.
It tells the UE how to leave the current NR context and proceed with the commanded mobility action.
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.