SMS cell broadcast service is the type of service bulk sms whereby the same message is broadcast to multiple SMS subscribers. Such service is only available to the network operators, and is normally used for messages like weather alerts and news reports.

SMS network architecture is based on the architecture of Global System for Mobile Communications (GSM). SMS is a store and forward data services. This means  that messages are not sent to the destination directly. Instead, messages are routed and stored in SMS Message Centre (SMSMC), and then forwarded to the destination.

An SMSMC provides a number of services, including the regulation and transfer of text messages between mobile phones. When a subscriber sends a text message to a recipient, the mobile phone actually sends the message to the SMSMC. The SMSMC stores the message and then delivers it to the designated recipient when they are available.

The SMSMC usually has a configurable validity period that determine how long it will store the message, and the user can usually specify a shorter validity period if they want. In addition to regulation of messages, the SMSMC also handles any charging that needs to take place. In general, there is at least one SMSMC per network.

This article aims to provide an introductory guide to the Short Message Service (SMS) which is part of the GSM specification. The limit in size of SMS is 160 characters if purely Latin alphabets are used. If non Latin alphabets such as Chinese characters are used, the limit will be 70 characters.