Question: In a scenario where a Gateway Control Session Establishment is indicated over S9, and no IP-CAN session is known to the H-PCRF for binding, how does the H-PCRF determine the type of access (home routed or visited) if an IP-CAN Session Establishment is subsequently received?
Option 1: Based on the UE's (User Equipment) location update in the HSS (Home Subscriber Server)
Option 2: Depending on whether the IP-CAN Session Establishment is received over Gx (for home routed) or S9 (for visited access), but this determination is not possible
Option 3: By querying the PDN-GW (Packet Data Network Gateway) for the UE's current access type
Option 4: If received over Gx, it's considered home routed; if received over S9, it's considered visited access
Explanation: The H-PCRF determines the access type based on the interface over which the IP-CAN Session Establishment is received. If it's received over Gx, it's considered home routed, and if over S9, it's considered visited access. This highlights the importance of interface-specific signaling in determining policy and charging rules in telecom networks.