Question: Upon receiving a request from the Short Message Service - Transaction Layer (SM-TL) to send a notification to the network while in Idle state, what action(s) does the Short Message Relay (SMR) entity in the Mobile Station (MS) take?
Option 1: Immediately sends an RP-ACK message and remains in Idle state.
Option 2: Enters the Wait for RP-ACK state without sending any message.
Option 3: Forms and transfers an RP-SMMA message, starts timer TR1M, and then enters the Wait for RP-ACK state.
Option 4: Rejects the request due to being in Idle state.
Explanation: When the SMR entity in the MS is in the Idle state and needs to relay a notification to the network as requested by the SM-TL, it initiates communication by forming and sending an RP-SMMA (Relay Protocol - Short Message Management Alert) message. To manage the response, it starts timer TR1M, which is likely set to await an acknowledgement from the network. Following these actions, the MS transitions from Idle to the Wait for RP-ACK state, indicating it is now awaiting a Response Packet Acknowledgement (RP-ACK) from the network, signifying successful receipt of the notification. This sequence ensures orderly communication setup and confirmation in mobile networks.