Question: In E-UTRAN to HRPD Interworking for non-emergency scenarios, how does a UE establish security association during pre-registration when moving from E-UTRAN to HRPD access network?
Option 1: The UE interacts with the MME in the E-UTRAN/EPS system, which then establishes the security association with the HRPD system on behalf of the UE.
Option 2: The security association is automatically transferred from the E-UTRAN/EPS system to the HRPD system without any direct interaction from the UE with the HRPD system.
Option 3: The UE's existing security context in the E-UTRAN/EPS system is used directly for authentication in the HRPD access network, eliminating the need for a new security association.
Option 4: The UE interacts directly with the HRPD system (through the HS-GW) to perform authentication and establish a new security association, with signaling tunneled over the E-UTRAN/EPS.
Explanation: This is correct because, according to interworking procedures, for pre-registration, the UE directly engages with the HRPD system (via the HS-GW) to authenticate and set up a security association. This process is distinct from the UE's interactions within the E-UTRAN/EPS system, although signaling for this setup is tunneled over the E-UTRAN/EPS infrastructure, ensuring secure authentication and key agreement with the HRPD access network.