Question: What is the typical response from the Short Message Relay (SMR) entity to the Service Centre after receiving an incoming RP-DATA on an established Connection Management (CM) connection in Point-to-Point Short Message Service (SMS)?
Option 1: CP-DATA message with a new RPDU
Option 2: Immediate setup of a new CM-connection for response
Option 3: No acknowledgement or error indication is sent
Option 4: Either an RP-ACK (acknowledgement) or an RP-ERROR (error indication)
Explanation: In the context of SMS over the mobile radio interface, after the SMR entity receives an incoming RP-DATA message, it is expected to respond with either a positive acknowledgement (RP-ACK) if the message is successfully received, or an error indication (RP-ERROR) if there's an issue. This ensures reliable communication between the SMR entity and the Service Centre, facilitating the management of SMS delivery.