Question: What is the primary purpose of the S101 interface between the MME and HRPD access in the context of E-UTRAN Access to cdma2000 HRPD Access handover?
Option 1: To facilitate RIM information exchange for network optimization
Option 2: To support direct data forwarding during mobility from E-UTRAN to HRPD
Option 3: To manage UE authentication procedures across different access networks
Option 4: To enable pre-registration and handover signalling with the target system for optimized HandOver (HO)
Explanation: The S101 interface's key role is optimizing handovers from E-UTRAN to cdma2000 HRPD Access by facilitating pre-registration and handover signalling, crucial for seamless mobility between these two access technologies. Options 1, 2, and 3 are incorrect as they describe functions not primarily associated with the S101 interface in this context.