| Protocol | lte-rrc | Network | lte |
|---|---|---|---|
| Spec | 3GPP TS 36.331 | Spec Section | 5.4.5, 6.2.2 |
| Direction | UE -> eNodeB | Message Type | Inter-RAT Handover Preparation |
| Full message name | LTE RRC UL Handover Preparation Transfer |
|---|---|
| Protocol | LTE-RRC |
| Technology | LTE |
| Direction | UE -> eNodeB |
| Interface | Uu |
| Signaling bearer / channel | SRB1 / UL-DCCH |
| Typical trigger | The UE has received HandoverFromEUTRAPreparationRequest and returns the requested cdma2000 preparation information. |
| Main purpose | Carries the UE-generated preparation result for the cdma2000 inter-RAT branch so the source side can continue with mobility execution. |
| Main specification | 3GPP TS 36.331, 5.4.5, 6.2.2 |
| Release added | Release 8 |
| Procedures where used | Inter-RAT Handover to cdma2000, Handover Preparation |
| Related timers | T304 |
Uplink LTE RRC message used by the UE to return cdma2000 handover preparation information to the source eNodeB.
Carries the UE-generated preparation result for the cdma2000 inter-RAT branch so the source side can continue with mobility execution.
UL Handover Preparation Transfer is the UE return step in the cdma2000 handover preparation exchange.
Call flow position: UE-to-network return step in the cdma2000 preparation branch.
Typical state: UE is in connected LTE signaling and is still on the source E-UTRA side.
Preconditions:
Next likely message: MobilityFromEUTRACommand
Call flow position: Uplink handover-preparation container delivered before final mobility execution.
Typical state: The source eNodeB is waiting for the UE-side preparation response.
Preconditions:
Next likely message: MobilityFromEUTRACommand
Previous message(s): HandoverFromEUTRAPreparationRequest
Next message(s): MobilityFromEUTRACommand
Security context: Normally sent as protected connected-mode signaling.
ULHandoverPreparationTransfer ::= SEQUENCE {
criticalExtensions CHOICE {
c1 CHOICE {
ulHandoverPreparationTransfer-r8 ULHandoverPreparationTransfer-r8-IEs,
spare3 NULL,
spare2 NULL,
spare1 NULL
},
criticalExtensionsFuture SEQUENCE {}
}
}
ULHandoverPreparationTransfer-r8-IEs ::= SEQUENCE {
cdma2000-Type CDMA2000-Type,
dedicatedInfo DedicatedInfoCDMA2000-1XRTT,
nonCriticalExtension SEQUENCE {} OPTIONAL
}
Read this message mainly as the UE return container in the cdma2000 preparation exchange.
UL-DCCH-Message
message c1 : ulHandoverPreparationTransfer : {
criticalExtensions c1 : ulHandoverPreparationTransfer-r8 : {
cdma2000-Type cdma2000-HRPD,
dedicatedInfo '93AA1105'H
}
}
| IE | Required | Description |
|---|---|---|
cdma2000-Type | Yes | Shows whether the uplink preparation result belongs to 1XRTT or HRPD. |
dedicatedInfo | Yes | Opaque preparation payload returned by the UE for the target branch. |
nonCriticalExtension | Optional | Release-extension branch. |
cdma2000-TypeShows whether the uplink preparation result belongs to 1XRTT or HRPD.
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.
dedicatedInfoOpaque preparation payload returned by the UE for the target 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.
nonCriticalExtensionRelease-extension branch.
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 uplink preparation transfer may be missing, malformed, or rejected in the wider source-side logic.
What to inspect: Check this message against the preceding request and the later absence of MobilityFromEUTRACommand.
Next step: Treat the issue as preparation-branch interruption rather than target-access failure.
It is the uplink LTE RRC message the UE uses to return the cdma2000 preparation payload to the source eNodeB.
The next important step is usually MobilityFromEUTRACommand if the preparation branch continues successfully.
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.