This paper presents an SMS based design in the GSM system for a portable, light weighted, and small sized TeleAlarm device. The device is composed of a transmitter and a controller. When an emergent situation such as a stroke or a fall occurs, the user only needs to push a button to trigger the controller. The controller automatically sends text messages stored in its database through the transmitter to specified mobile phone numbers for help. The SMS uses only the control channels in the GSM system to transfer the message, which enables the receiving-end user to receive it even during a call. An experimental test shows that a complete message transmission only needs 2.949 seconds in average. The design is convenient to elderly people who may live alone.
A SHORT MESSAGE SERVICE BASED DESIGN FOR A PORTABLE TELEALARM DEVICE