MOBILE PHONE JAMMERDEEPAK BHOJWANI

4TH YEAR

COMPUTER SCIENCE

WHAT IS A MOBILE PHONE?

A mobile phone (also known as a cellular phone, cell phone, and a hand phone) is a device that can make and receive telephone calls over a radio link while moving around a wide geographic area.

It does so by connecting to a cellular network provided by a mobile phone operator, allowing access to the public telephone network.

support a wide variety of other services such as text messaging, MMS, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, gaming and photography.

WHAT IS A MOBILE PHONE JAMMER?

A mobile phone jammer is an instrument used to prevent cellular phones from receiving signals from base stations

 These devices can be used in practically any location, but are found primarily in places where a phone call would be particularly disruptive because silence is expected.

OPERATION

As with other radio jamming, cell phone jammers block cell phone use by sending out radio waves along the same frequencies that cellular phones use.

This causes enough interference with the communication between cell phones and towers to render the phones unusable.

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

COMPONENT OF A JAMMER

Antenna

Circuitry

Power supply

ANTENNA Every jamming device has an antenna to send the

signal.

On stronger devices, antennas are external to provide longer range and may be tuned for individual frequencies.

CIRCUITRY

The main electronic components of a jammer are: Voltage-controlled oscillator — Generates the radio

signal that will interfere with the cell phone signal

Tuning circuit — Controls the frequency at which the jammer broadcasts its signal by sending a particular voltage to the oscillator

Noise generator — Produces random electronic output in a specified frequency range to jam the cell-phone network signal (part of the tuning circuit)

RF amplification (gain stage) — Boosts the power of the radio frequency output to high enough levels to jam a signal

POWER SUPPLY

Smaller jamming devices are battery operated. Some look like cell phones and use cell phone batteries.

Stronger devices can be plugged into a standard outlet or wired into a vehicle's electrical system.

DESIGN PARAMETERS The distance to be jammed (D)

The frequency bands

Jamming– to-signal ratio {J/S}

Free space loss {F}

JAMMING TECHNIQUE

TYPE A

TYPE B

TYPE C

TYPE D

TYPE E

TYPE A

This type of device comes equipped with several independent oscillators transmitting ’jamming signals’ capable of blocking frequencies used by paging devices as well as those used by cellular systems control channels for call establishment.

TYPE B

Unlike jammers, Type ”B” devices do not transmit an interfering signal on the control channels.

The device, when located in a designated ’quite’ area, functions as a ’detector’. It has a unique identification number for communicating with the cellular base station.

TYPE C

The device, when located in a designated ’quiet’ area, functions as a ’beacon’ and any compatible terminal is instructed to disable its ringer or disable its operation, while within the coverage area of beacon.

TYPE D

This jammer behaves like a small, independent and portable base station, which can directly interact intelligently or unintelligently with the operation of the local mobile phone.

The jammer is predominantly in receive mode and will intelligently choose to interact and block the cell Phone directly if it is within close proximity of the jammer.

TYPE E

This technique is using EMI suppression techniques to make a room into what is called Faraday cage

Although labor intensive to construct, the Faraday cage essentially Blocks or greatly attenuates, virtually all electromagnetic radiation from entering or leaving the cage - or in this case a target room..

SK-6 ULTRA-THIN CELL PHONE JAMMER

SK-6 cell phone jammer is more and more popular used in examination halls, examination rooms, test rooms, libraries and so on. The cell phone jammer is the best instrument can help examiners to prevent students cheating with cellular phones in the examinations.

is the latest electronic product which transmits low power radio signals to block the communication signal bandwidths in GSM, CDMA, PHS, DCS, IDEN, UMTS, GPS, WiFi, Bluetooth, etc.

FEATURES OF SK-6 CELL PHONE JAMMER

Show the working power on the shell with green lights Prevent cheating by using cell phone in the

examinations Keeping you away from the noise or disturbance of

unexpected cell phone calls or SMS in the class time or meeting time.

Mini-size medium power cell phone jammer Low weight and Nice texture and color To block wireless phone communication links within an

effective area. No transmissions or receptions of cell phone call in

coverage area. All specified frequency bands will be blocked

simultaneously.

APPLICATIONS Cell phone jamming devices were originally developed

for law enforcement and the military to interrupt communications by criminals and terrorists

The bombs that blew up commuter trains in Spain in March 2004, as well as blasts in Bali in October 2002 and Jakarta in August 2003, all relied on cell phones to trigger explosives.

During a hostage situation, police can control when and where a captor can make a phone call. Police can block phone calls during a drug raid so suspects can't communicate outside the area.

jammers can be used in areas where radio transmissions are dangerous, (areas with a potentially explosive atmosphere), such as chemical storage facilities or grain elevators.

Corporations use jammers to stop corporate espionage by blocking voice transmissions and photo transmissions from camera phones.

CONCLUSION Every device is acts as good aspects as well as bad

aspects.

In many place cell phone jammer is useful but at many place it is a problem.

But it’s overall performance is very good and helpful in our life.

THANK YOU

QUERIES?????