Section: 5.5.2.1.4 E-UTRAN to UTRAN Iu mode Inter RAT handover Reject
Content: The Target RNC may reject the use of the Handover procedure if none of the requested RABs in the Relocation Request message could be established. In this case no UE context is established in the target SGSN/RNC and no resources are allocated. The UE remains in the Source eNodeB/MME. Figure 5.5.2.1.4-1: E-UTRAN to UTRAN Iu mode Inter RAT HO reject 1. The Step 1 to 5 in the flow are identical to the ones in clause 5.5.2.1.2. 6. If the Target RNC fails to allocate any resources for any of the requested RABs it sends a Relocation Failure (Cause) message to the Target SGSN. When the Target SGSN receives the Relocation Failure message from Target RNC the Target SGSN clears any reserved resources for this UE. 7. This step is only performed for Serving GW relocation, i.e. if Steps 4/4a have been performed. The Target SGSN deletes the EPS bearer resources by sending Delete Session Request (Cause) messages to the Target Serving GW. The Target Serving GW acknowledges with Delete Session Response (Cause) messages. 8. The Target SGSN sends the Forward Relocation Response (Cause) message to the Source MME. 9. When the Source MME receives the Forward Relocation Response message it send a Handover Preparation Failure (Cause) message to the Source eNodeB.