76 Kajal Varshney, Khushboo Verma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 3, Issue 9

November 2014

MOBILE PHONE JAMMER FOR GSM & CDMA

Kajal Varshney

B.Tech dept. computer science

Rkgitw college

Ghaziabad

Khushboo Verma B.tech dept. computer science

Rkgitw college

Ghaziabad

ABSTRACT This Paper is designed and implemented for Mobile phone signal jammer for GSM, CDMA with

prescheduled time duration using Mobile jammer. Mobile jammer is used to prevent mobile phones

from receiving or transmitting signals with the base stations. Mobile jammer effectively disable

mobile phones within the defined regulated zones without causing any interference to other

communication means. The jamming device broadcasts an RF signal with the cell phones that

interferes with the cell phone signal by which all mobile phones will indicate "NO NETWORK ”.

Real time clock chip is used to set the schedule.

Keywords

ARM7, keypad, Mobile jammer, RTC.

INTRODUCTION

Communication jamming devices were first developed and used by military. Where tactical

commanders use RF communications to exercise control of their forces, an enemy has interest in

those communications. This interest comes from the fundamental area of denying the successful

transport of the information from the sender to the receiver. Nowadays the mobile jammer devices

are becoming civilian products rather than electronic warfare devices, since with the increasing

number of the mobile phone users the need to disable mobile phones in specific places where the

ringing of cell phone would be disruptive has increased. These places include worship places,

university lecture rooms, libraries, concert halls, meeting rooms, and other places where silence is

appreciated.

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 jammer for government switched over to sell these devices to private

entities.

77 Kajal Varshney, Khushboo Verma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 3, Issue 9

November 2014

As with other radio jamming, mobile jammer 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 jammer, all mobile phones will indicate "NO NETWORK ”(1). 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

jammer’s effect can vary widely based on factors such as proximity to towers, indoor and outdoor

settings, presence of buildings and landscape, even temperature and humidity play a role.

A device designed to operate within the frequency bands 870-960 MHz or 825-845 MHz and

to interfere with radio communications or disrupt or disturb radio communications, except

where.

The device is designed to facilitate a cellular mobile telephone service on board an aircraft

that operates on another frequency; and the device is operated for that purpose.

1.RELATED WORK

Mobile jammer is used to prevent mobile phones from Receiving transmitting signals with the

base stations. Mobile jammer effectively disable mobile phones within the defined regulated zones

without causing any interference to other communication means Mobile jammer can be used in

practically any location, but are used in places where a phone call would be particularly disruptive

like Temples, Libraries, Hospitals etc. As with other radio jamming, mobile jammer 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

tower to render the phones unusable.

Jammers can work by either disrupting phone to tower frequencies or tower to phone frequencies.

Smaller handheld models block all bands from 800 MHz to 1900 MHz within a 30-foot range [9

meters](2).

Figure1. Basic principle of mobile jammer

Power

supply

Oscillat

or

Noise

generat

or

Amp

lifier

Ante

nna

Tuning

circuit

78 Kajal Varshney, Khushboo Verma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 3, Issue 9

November 2014

2. JAMMING TECHNIQUES

There are several ways to jam an RF device. The three most common techniques can be categorized

as follows:

2.1.Spoofing: In this kind of jamming, the device forces the mobile to turn off itself. This type is

very difficult to be implemented since the jamming device first detects any mobile phone in a

specific area, then the device sends the signal to disable the mobile phone(3). Some types of this

technique can detect if a nearby mobile phone is there and sends a message to tell the user to switch

the phone to the silent mode (Intelligent Beacon

Disablers).

2.2.Shielding attacks: this is known as tempest or

EMF shielding. This kind requires closing an area in

a faraday cage

so that any device inside this cage can’t transmit or

receive RF signal from outside of the cage.

2.3.Denial of service: This technique is referred to

DOS. In this technique, the device transmits a noise

signal at the same operating frequency of the mobile

phone in order to decrease the signal-to-noise ratio

(SNR) of the mobile under its minimum value. This

kind of jamming technique is the simplest one since

the device is always on(4). Our device is of this type.

Mobile jammer circuit includes IF section, RF

section, Antenna and Power supply.

Figure2. Block diagram of mobile jammer

In our design, the jamming frequency must be the same as the downlink, because it needs lower

power to do jamming than the uplink range and there is no need to jam the base station itself. So, our

frequency design will be as follows: GSM 900 -- 935-960 MHZ(5) GSM 1800-- 1805-1880 MHZ

The CDMA frequency range will be 860-894 MHZ (Asia & Europe) and 850-894 MHZ (United

States).

Power

supply

IF-

section

RF-

section

Jamming

signal

79 Kajal Varshney, Khushboo Verma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 3, Issue 9

November 2014

TABLE 1. OPERATING FREQUENCY BANDS

UPLIN

K

DOWNLI

NK

USED IN

JORDAN

By:

GSM

900

890-915

MHz

935-960

MHz

Zain + Orange

DCS

1800

1710-

1785

MHz

1805-1880

MHz

Umniah

3.ARM7

The arm7 family is the world's most widely used 32-bit embedded processor family, with more than

170 silicon licensees and over 10 billion units shipped since its introduction in 1994. While the arm7

processor family continues to be used today for simple 32-bit devices, newer digital designs are

increasingly making use of the newer, more powerful and feature-rich arm processors which offer

significant technical enhancements over the arm7 family. System designers wishing to upgrade from

arm7 benefit from a robust arm processor roadmap providing multiple upgrade options, including the

latest cortex processors. In most cases migration is straightforward, and brings significant benefits in

PPA, features and efficiency(6)

4 .RTC

A real-time clock (RTC) is a computer clock (most often in the form of an integrated circuit) that

keeps track of the current time. Although the term often refers to the devices in personal computers,

servers and embedded systems, RTCs are present in almost any electronic device which needs to

keep accurate time.

A real-time clock (RTC) is a battery-powered clock that is included in a microchip in a computer

motherboard. This microchip is usually separate from the microprocessor and other chips and is

often referred to simply as "the CMOS" (complementary metal-oxide semiconductor). A small

memory on this microchip stores system description or setup values - including current time values

stored by the real-time clock. The time values are for the year, month, date, hours, minutes, and

seconds. When the computer is turned on, the Basic Input-Output Operating System (BIOS) that is

stored in the computer's read-only memory (ROM) microchip reads the current time from the

memory in the chip with the real-time clock.

80 Kajal Varshney, Khushboo Verma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 3, Issue 9

November 2014

5.KEYPAD

A basic 12 button keypad for user input. The buttons are setup in a matrix format. This allows a

microcontroller to scan the 7 output pins to see which of the 12 buttons is being pressed. The jammer

ON time and OFF time will be given with the help of keypad(7).

Figure 4. A 4*3 matrix keypad

FUTURE SCOPE

Mobile phone jammers used in the military, can effectively prevent leak important military

secrets.

Mobile phone signal blocker used in the examination rooms, can effectively prevent cheat

through mobile communications.

Cell phone signal blocker used in schools, can assure students to study without distraction

and have a quiet rest.

Cell phone jammer used in theaters, can make everyone en- joy the program without disturb.

Mobile phone jammer used in meeting rooms or training rooms, can assure the effective of

the meeting.

In fact, cell phone jammer is urgent needed in jails. At present, all countries in the world have

regulation that forbidden use of mobile phones in prison, but due to the defect of

management, it's difficult to do that.

CONCLUSION

This paper is successfully completed using Mobile jammer and ARM7. By this system we can

deactivate all the mobile signals at any location. we designed a device that stops phone ringing in a

particular time period. This device could be Use in places where ringing is not desired at specific

times, as these ringing may disturb people in such places. The designed device works in dual band. It

81 Kajal Varshney, Khushboo Verma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 3, Issue 9

November 2014

jams both the GSM 900 and GSM 1800 bands. The device was able to jam the three main cell phone

carriers in Jordan.

REFERENCES

1) www.HowStuffWork.com.

2) Multitopic conference 2008, INMIC 2008 IEEE international.

3) “zone of silence [cell phone jammer],” Spectrum, IEEE, vol.42,no.5, 18, may 2005

References.Sami Azzam, Ahmad Hijazi, Ali Mahmoudy.”smart jammer for mobile phone

systems”.

4) John Scourias overview of the global system for mobile global system for

Mobilecommunications, http://ccnga.uwaterloo.ca/~jscouria/GSM/gsmreport

5) Mobile & Personal Communications Committee of the radio advisory board of Canada, ”use

of jammer and disable devices for blocking PCS, cellular and related services”.

6) International journal of science, engineering and technology research(IJSETR) volume 2,

issue 9,September 2013 references.