Question: In a Universal Subscriber Identity Module (USIM) Application Toolkit (USAT), how does a Mobile Equipment (ME) handle the response timing for steering of roaming procedures to avoid blocking the Toolkit interface?
Option 1: The ME waits for the completion of the steering of roaming procedure before sending a TERMINAL RESPONSE.
Option 2: The ME sends a TERMINAL RESPONSE (Command performed successfully) immediately after starting the procedure, without waiting for its completion.
Option 3: The ME only sends a TERMINAL RESPONSE if the steering of roaming procedure fails to start.
Option 4: The ME periodically sends UPDATE RESPONSEs until the steering of roaming procedure is completed.
Explanation: To prevent the Toolkit interface from being blocked due to potentially lengthy steering of roaming procedures, the Mobile Equipment (ME) is designed to acknowledge the initiation of the process promptly. By sending a TERMINAL RESPONSE (indicating the command was performed successfully) immediately after starting the procedure, the ME ensures the interface remains available for other commands without delay, aligning with efficient operational principles in telecom networks.