Question: In SMS according to 3GPP standards, what is the significance of the first '#' character encountered in the TP-Originating-Address (TP-OA) field?
Option 1: It separates the sender's phone number from their name.
Option 2: It indicates the termination point for the address used for SMSC routing purposes.
Option 3: It marks the beginning of a special service code within the originating address.
Option 4: It is used to differentiate between national and international originator addresses.
Explanation: The first '#' character in the TP-Originating-Address field is crucial for Short Message Service Centers (SMSCs) to correctly route messages, as it delineates the end of the routing address within the originating address field.