The SMS network / The GSM SMS protocol explained

If you operate SMS services, it is a good pratice to educate your staff about the SMS network and the SMS porotocol used to transfer messages inside the mobile network. This guide helps you in this aspect. It gives a comprehensive overview of the SMS infrastructure and the SMS protocol used inside mobile networks.

Table of contents

  • Important terms and definitions (MS,SME,SMSC,MMI,PDU,SM-AL,SM-TL,...)
  • SMS network entities
  • SMS protocol data unit (PDU) format
  • SMS text encoding
  • PDU examples
  • Sending PDUs using modems
  • The default SMS alphabet
  • Glossary
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