Section: 5.5.2.2 UTRAN Iu mode to E-UTRAN Inter RAT handover 5.5.2.2.1 General
Content: The UTRAN Iu mode to E-UTRAN Inter RAT handover procedure takes place when the network decides to perform a handover. The decision to perform PS handover from UTRAN Iu mode to E-UTRAN is taken by the network based on radio condition measurements reported by the UE to the UTRAN RNC. If emergency bearer services are ongoing for the UE, the MME checks as part of the Tracking Area Update in the execution phase, if the handover is to a restricted area and if so MME releases the non-emergency bearers as specified in clause 5.10.3. If emergency bearer services are ongoing for the UE, the source SGSN evaluates the handover to the target CSG cell independent of the UE's CSG subscription. If the handover is to a CSG cell that the UE is not subscribed, the target eNodeB only accepts the emergency bearers and the target MME releases the non-emergency PDN connections that were not accepted by the target eNodeB as specified in clause 5.10.3.