Question: What is the primary purpose of the Service-Centre-Time-Stamp information element in the context of Short Message Service (SMS) as per 3GPP standards?
Option 1: To inform the recipient Mobile Station (MS: Mobile Equipment and its related User Equipment) about the time a short message arrived at the Short Message Service Centre's (SC) SM-TL entity.
Option 2: To synchronize the clocks of all Mobile Stations (MS) with the network's central clock for unified timing.
Option 3: To provide a unique identifier for each SMS to prevent duplication during transmission.
Option 4: To indicate the Quality of Service (QoS) level assigned to an SMS for prioritization in congested networks.
Explanation: The correct answer is Option 1 because the Service-Centre-Time-Stamp specifically serves to notify the recipient's Mobile Station about the arrival time of a short message at the SC's SM-TL entity, enhancing transparency and traceability within the SMS delivery process. This aligns with efficient service management and user experience in telecom networks.