GSM (Global System for Mobile Communications) is an open digital cellular technology used to transmit mobile voice and data services. GSM differs from first generation wireless systems in that it uses digital technology and Time Division Multiple Access (TDMA) transmission methods. GSM is a circuit switched system that divides each 200 kHz channel into eight 25 kHz time slots. GSM operates in the 900MHz and 1.8GHz bands in Europe and the bands 1.9GHz and 850MHz in the USA. The 850MHz band is also used for GSM and 3GSM in Australia, Canada and many countries in South America. GSM supports data transfer speeds of up to 9.6 kbit / s, allowing the transmission of basic data services such as SMS (Short Message Service). Another important advantage is its international roaming capability, which allows users to access the same services when traveling abroad as at home. This gives consumers seamless and equal connectivity in more than 210 countries. GSM satellite roaming has also expanded access to services in areas where there is no terrestrial coverage. Global System for Mobile Communications.
Today vehicle thefts are increasing at a rapid pace, and therefore, safety has become a very crucial aspect for vehicles and other transportation systems vulnerable to theft. In this proposed system, if someone tries to steal a vehicle, the information relating to the vehicle in question is sent to the owner of the vehicle by SMS through GSM technology. An additional advantage of this project is that the owner can return the SMS, which will disable the ignition of the vehicle.
The GSM modem is connected to the microcontroller with the help of a MAX-232 device to establish communication with the vehicle. A relay is controlled by a relay exciter IC that is connected to the microcontroller. In this system, for indication purposes, instead of a motor a lamp is connected to the relay contracts.
If someone tries to steal the vehicle with this system, the circuits in this system generate an interrupt, which is sent to the programmable microcontroller that stores the owner number when receiving a missed call from the owner for the first time. The microcontroller sends the stolen information to the owner via an SMS via a GSM modem. The owner can immediately return an SMS to the GSM modem, forcing the system to stop the vehicle engine immediately. The microcontroller gives control instructions to the relay driver to trigger the relay that disconnects the lamp, used at the motor site - for practical demonstration purposes.
Block diagram
![[Image: Theft_Intimation_of_the_Vehicle_Over_GSM...gram_A.JPG]](http://www.efxkits.com/media/wysiwyg/Theft_Intimation_of_the_Vehicle_Over_GSM_by_SMS_with_User_Programmable_Number_Featureto_Owner_who_can_Stop_the_Engine_Remotely_Block_Diagram_A.JPG)
