Question: What is a key aspect of Inter-RAT inbound mobility to E-UTRAN Closed Subscriber Group (CSG) cells when a User Equipment (UE) is camped on a Radio Access Technology (RAT) other than E-UTRAN?
Option 1: The UE relies on the E-UTRAN CSG cell's autonomous search functionality.
Option 2: The UE's mobility is managed solely by the serving non-E-UTRAN RAT's handover procedures.
Option 3: The UE performs an autonomous search, with requirements defined in E-UTRAN specifications.
Option 4: Inter-RAT inbound mobility to E-UTRAN CSG cells is not supported when the UE is camped on another RAT.
Explanation: In Inter-RAT mobility, for a UE to move from a different RAT to an E-UTRAN Closed Subscriber Group (CSG) cell, the UE initiates actions to find and connect to the new cell. This relies on the UE's autonomous search functionality towards E-UTRAN CSG cells, guided by its operational specifications across different RATs.