4. Core Components

4.1 SMSC Core

The SMS Service Centre is responsible for relaying and store-and-forward of short messages [3GPP TS 23.040]. Upon receiving a message, the SC stores it and assumes responsibility to deliver it to the recipient. It retains the message until delivery is confirmed by a report or the message’s validity period expires. This entails queuing undelivered messages, scheduling retries, and expiring messages that exceed their validity. The SC also generates status reports (delivery receipts) if requested – for example, sending an acknowledgment back to the originator when the message is delivered to the mobile or if it failed after expiry. (Notably, support for status reports is optional per operator policy.) Overall, the SMSC core implements 3GPP’s store-and-forward paradigm: it submits messages to the network, stores them until delivered, and receives/returns delivery reports as needed.

Key functions