Question: What action does a VLR take when it receives an SGsAP-LOCATION-UPDATE-REQUEST message from the same MME with a different New Location Area Identifier while another update request is pending (state is LA-UPDATE PRESENT)?
Option 1: Ignore the new message and wait for the previous update to complete.
Option 2: Send a rejection for the new request due to an ongoing process.
Option 3: Abort the previous update process but do not send any response for it, then proceed with the new update.
Option 4: Treat the new message as an override, abandoning the response to the previous request but not explicitly rejecting it.
Explanation: According to VLR's abnormal case handling, when a new SGsAP-LOCATION-UPDATE-REQUEST is received from the same MME with different location area info while an update is pending, the VLR treats this new message as an override. It abandons the response to the previous request (neither accepting nor rejecting it explicitly) and proceeds with the new location update for non-EPS services, ensuring seamless handling of updated location information without unnecessary rejection messages.