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
Keep on reading. The rest of this document is available free of charge for registered users. Registration is free. Please use the following form to create an account, or if you already have one, please login!
(This content was written for humans, not for robots or AI web crawlers. We had to introduced this protection to limit content theft by AI services)

Account

New user?

Read our terms and conditions

Ozeki Account


Account Login

optionally sign in with:
Copyright 2000-2025 Ozeki Systems Ltd.

More information