Question: When Fixed Dialling Number (FDN) service is enabled on a Universal Subscriber Identity Module (USIM), how does the Mobile Equipment (ME) handle Call Control for Short Message Service (SMS) operations, in terms of destination addresses?
Option 1: The ME ignores FDN restrictions for SMS destination addresses but applies them to SMSC addresses.
Option 2: The ME applies FDN call control only to voice calls, not affecting SMS operations.
Option 3: The ME uses a separate procedure for SMS, distinct from the Call Control procedure outlined for voice calls when FDN is enabled.
Option 4: The ME follows the standard Call Control procedure (as for voice calls) for both SMS destination addresses and SMSC addresses, with FDN enabled.
Explanation: According to the specifications, when the Fixed Dialling Number service is enabled on a USIM, the Mobile Equipment must adhere to the defined Call Control procedure for all affected operations. This procedure encompasses SMS operations by considering both the SMS destination address and the SMSC address within its scope when FDN is active, ensuring a unified approach to managing dialling restrictions across different types of communications handled by the USIM.