These technologies, both hardware and software, have been specifically chosen to be relatively accessible within a modest budget and offer sustainable effeciency.
[url removed, login to view] GSM Modem
A GSM modem can be an external device or a PC Card / PCMCIA Card. Typically, an external
GSM modem is connected to a computer through a serial cable or a USB cable. Like a GSM mobile
phone, a GSM modem requires a SIM card from a Service Provider in order to operate. A GSM
modem is the preferred device in comparison to a GSM mobile phone since they have a standard
interface, have basic required functionality, are comparatively cheaper and connect to a standard
USB 2.0 port without the need for an external power input.
GSM modems accept the common set of standard AT commands*1. In addition to the standard AT
commands, GSM modems support an extended set of AT commands. These extended AT
commands are defined in the GSM standards. With the extended AT commands, you can do things
Reading, writing and deleting SMS messages.
Sending SMS messages.
Monitoring the signal strength.
Monitoring the charging status and charge level of the battery.
Reading, writing and searching phone book entries.
The number of SMS messages that can be processed by a GSM modem per minute is relatively low
¬¬ only about twenty SMS messages per minute. There are however advanced types of GSM
Moidems that support larger volume transactions designed specifically for this purpose and are the
type deployed by Premium Rate Service Providers at the server back¬end.
2.1.2 Personal Computer or Laptop
A low end PC (Intel Pentium III/IV) that has a Database and Database Management System
(DBMS) installed is suffecient to collect information from the GSM Modem. It is also important
that this computer have a fast USB 2.0 port since the data transfer rate is crucial to the effeciency of
the system. Older USB 1.1 ports are growing obsolete but can be acceptable for prototyping purposes.
1 AT commands are instructions used to control a modem. AT is the abbreviation of ATtention. Every command line starts
with "AT" or "at". That's why modem commands are called AT commands. These are discussed in the appendix.
2.2.1 Database Management System
A relational database management system (RDBMS) is an essential tool in many environments,
from traditional uses in business, research, and educational contexts. However, despite the
importance of a good database system for managing and accessing information resources, many
organizations have found them to be out of reach of their financial resources.
Small desktop systems and servers are inexpensive but powerful, and there is a thriving movement devoted to writing high­performance operating systems for [url removed, login to view] operating systems such as the one used for this Project are available free over the Internet or at the cost of an inexpensive CD.
Database software has become more accessible, too, and Open Source database systems are freely
available. One of these is MySQL, a SQL client/server relational database management system
originating from Scandinavia. MySQL includes an SQL server, client programs for accessing the
server, administrative tools, and a programming interface for writing programs.
2.2.2 The LAMP Environment
Linux, Apache WebServer, MySQL and PHP, and Cascading Style Sheets
PHP is a programming language designed to generate web pages interactively on the computer
serving them, which is called a web server. Unlike HTML, where the web browser uses tags and
markup to generate a page, PHP code runs between the requested page and the web server, adding to
and changing the basic HTML output. These provide the main interface for the user to view
information from the database.
Apache is a web server that turns browser requests into resulting web pages and knows how to
process PHP code. PHP is only a programming language, so without the power of a web server like