Design And Construction Of An Active Mobile Phone Detector

ABSTRACT

This work is on an active mobile phone detector which senses the presence of an activated mobile cell phone from a distance of one and-a-half meters. So it can be used top revent use of mobile phones in examination halls, confidential rooms, etc. It is also useful for detecting the use of mobile phone for Spying and unauthorized video transmission. The circuit can detect the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. The moment the Bug detects RF transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks. The alarm continues until the signal transmission ceases.

CHAPTER ONE

1.0                                                        INTRODUCTION

As increase in the technology in the world using the electronic equipments are being used in a wrong way like, in the examination halls and confidential rooms. To avoid this we are introducing a project called CELLPHONE DETECTOR This handy, pocket-size mobile  detector or sniffer can sense the presence of an activated mobile cell phone from a distance of more than one and-a-half meters. So it can be used to prevent use of mobile phones in examination halls, confidential rooms, etc. It is also useful for detecting the use of mobile phone for Spying and unauthorized video transmission. The circuit can detect the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. The moment the Bug detects RF transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks. The alarm continues until the signal transmission ceases. Problem Statement Previously, there was no technology to detect the cell phones in the examination hall and in cell phone restricted areas. There is manual checking and there is still a chance of having the cell phone with the person if he is not checked properly. So to avoid this problem, an automatic detection of cell phone is introduced. Motivation Cell phones are used in good way and also in a bad way. When the class is going on, students intend to use their cell phones and not listening to what is being taught. These days, students are also carrying their cell phones to the examination halls to copy which would help them to get good marks. To avoid this problem, the cell phone detector is introduced.

This device can notice the use of GSM mobile phone in mobile restricted areas such as Examination hall or confidential rooms etc. It is just like a sniffer mobile that can sense the activity of mobile phone from a distance of 5 meters or more. The device can detect both incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode.

1.1                                       AIM /OBJECTIVE OF THE PROJECT

The aim/objective of this circuit is to receive the RF signal from the mobile phones & detect its presence by alarming the sound.

1.2                                         SIGNIFICANCE OF THE PROJECT

This device is intended to detect unauthorized use of mobile phones in examination halls, confidential rooms etc. It also helps to detect unauthorized video and audio recordings. It detects the signal from mobile phones even if it is kept in the silent mode. It also detects SMS. CONCEPT Mobile phone uses RF with a wavelength of 30cm at 872 to 2170 MHz. That is the signal is high frequency with huge energy. When the mobile phone is active, it transmits the signal in the form of sine wave which passes through the space. The encoded audio/video signal contains electromagnetic radiation which is picked up by the receiver in the base station. Mobile phone system is referred to as “Cellular Telephone system” because the coverage area is divided into “cells” each of which has a base station.

1.3                                          APPLICATION OF THE PROJECT

• It can be used to prevent use of mobile phones in examination halls, confidential rooms , etc.
• It is also useful for detecting the use of mobile phone for spying and unauthorized video transmission.
• It is useful where the use of mobile phone is prohibited Like petrol pumps and gas stations, historical places, religious places and court of laws 29

1.4                                           LIMITATION OF THE PROJECT

Some common problems with mobile phone detector are:

• detection of one mobile phone at a time. Is most difficult to receive multi signal at a time.
• Soldering of the circuit is not proper than the circuit will not receive
• The proper signal Range of the system is very small so it can cover only the radius ofØ few meters so it will detect only small number of units under its radius.
• The prototype version has only limited range of 5 meters. But if a preamplifier stage using JFET or MOSFET transistor is used as an interface between the capacitor and IC, range can be increased.
• Mobile phone can only be detected if it is switched on and ONLINE mode.

1.5                                         FUTURE WORK OF THE PROJECT

• Trying to increase the detecting range of mobile bug to few more meters for observing wide range of area.

1.6                          PROJECT WORK ORGANIZATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to an active mobile phone detector. In this chapter, the background, significance, objective limitation and problem of an active mobile phone detector were discussed.

Chapter two is on literature review of an active mobile phone detector. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.