This paper describes the design and implementation of an SMS transmission system using the PDU (Protocol Data Unit) mode of a GSM (Global System for Mobile Communications) modem. The system may be used in several applications: telemetry or remote control, using short messages from a standard GSM mobile phone, and in other application circuits. In order to perform these applications, coding and decoding of the short messages into PDU mode is required. In other words, the source needs to be coded and the numbers need to be targeted in the PDU. In this instance, the circuit was tested using a Siemens S25 mobile telephone. KEYWORDS Wireless Applications, Electronic Data Interchange, Mobile communications, Telecontrol, Telemetry.