Mobile Phone signal Isolator for GSM and CDMA networks with prescheduled duration

Title of the project: Mobile Phone signal Isolator for GSM and CDMA networks with prescheduled duration
Domain: Wireless Communication & Embedded Systems
Software: Embedded C, Keil, Proload
Microcontroller: AT89S52
Power Supply: +5V, 500mA Regulated Power Supply
Display: a) LCD b) LED
LCD: HD44780 16-character, 2-line (16X2)
LED: 5mm
Crystal: 11.0592MHz
RTC: DS1307
Applications: Security, Defense, Institutions, Libraries, Seminar Halls


ABSTRACT


BACKGROUND OF THE PROJECT
Mobile jammer is used to prevent mobile phones from receiving or transmitting signals with the base stations. Mobile jammers effectively disable mobile phones within the defined regulated zones without causing any interference to other communication means. Mobile jammers can be used in
practically any location, but are used in places where a phone call would be particularly disruptive like Temples, Libraries, Hospitals, Cinema halls, schools & colleges etc.
As with other radio jamming, mobile jammers block mobile phone use by sending out radio waves along the same frequencies that mobile phones use.
This causes enough interference with the communication between mobile phones and communicating towers to render the phones unusable. Upon activating mobile jammers, all mobile phones will indicate "NO NETWORK". Incoming calls are blocked as if the mobile phone were off. When the mobile jammers are turned off, all mobile phones will automatically re-establish communications and provide full service.
Mobile Jammers were originally developed for law enforcement and the military to interrupt communications by criminals and terrorists to foil the use of certain remotely detonated explosives. The civilian applications were apparent with growing public resentment over usage of mobile phones in public areas on the rise & reckless invasion of privacy. Over time many companies originally contracted to design mobile jammers for government switched over to sell these devices to private entities.
In this project, we are controlling this mobile jammer by means of a microcontroller. The activation and deactivation time schedules can be programmed with microcontroller. Real time clock chip DS1307 is used to set the schedule.
This project uses regulated 5V, 500mA power supply. Unregulated 12V DC is used for relay. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac out put of secondary of 230/12V step down transformer.




Advantages:
Easy to operate
Sophisticated security
Simple and Reliable Design
Isolates both GSM and CDMA mobile signal
Scheduled time of operation can be programmed
Works with reference to Real Time Clock
Applications:
Defense Applications
Libraries
Temples
Colleges
Seminar halls and conference rooms
Security for VIPs during their visit to public places