This Cell phone signal jammer circuit using timer will effectively jam all types of mobile band signals. You can make this easily at home. broadcasts an RF signal in the frequency range reserved for cell phones that mentioned that cell phone jammers are illegal devices in most countries. Why are cell phone jammers, Wi-Fi jammers, and GPS jammers illegal? 6. Some devices claim to block cell phone calls, text messages, and emails only inside a.
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PDF | 60 minutes read | Dissimilar cellular-systems process signals differently, and yet, all cell-phone-networks use radio-signals that can be interrupted or, even. DESIGN AND CONSTRUCTION OF MOBILE PHONE JAMMER USING EXTRINSIC NOISE ABDULMAJEED MUHAMMAD KABIR Department of Electrical and. I declare that this report entitled “Cell phone Jammers Circuit Design and implementation” is caite.info caite.info
They were originally developed for law enforcement and the military tointerrupt communications by criminals and terrorists. Although the internal construction of the IC is somewhatdifferent from that described for discrete voltage regulator circuits, the external operationis much the same. For this, we used a two-stage amplification mechanism. The device, when located in a designated 'quiet' area, functions as a 'detector'. Current flowing through the coil of the relaycreates a magnetic field which attracts a lever and changes the switch contacts.
Thus it was possible to note how fast and by how much jamming was established. Livewire simulator package was used for some simulation tasks Each passive component was tested and value verified with respect to circuit diagram and available datasheet, this was done with the aid of the multimeter.
Using laboratory breadboard, a prototype circuit was built and then transferred to a permanent circuit Vero-board. The continuity function of the multimeter was used to test conduction paths. The output of each circuit section was tested with the oscilloscope, clean probes were used and the time and voltage divisions were properly set to ensure the required output signal was visible.
Noise circuit was tested while the laboratory fan was operational. It was observed that the signal bars decreased and eventually went off.
Range of the jammer was found to be around 10meters in indoor conditions. Intermediate frequency and Noise circuit diagram Fig. Oscilloscope readings of Noise signals Fig. Jammed Blackberry mobile phone 5. The improvised smart techniques which students use in various forms of examination malpractices by which mobile phones are employed need to be curtailed.
Likewise, communication between mobile stations can serve as a means of detonating improvised explosive devices IEDs , a technique that is applied by both veteran and amateur terrorists, this is a major threat to life and property and is experienced worldwide. Since a mobile phone jammer thus proves a effective way of blocking the radio air-interface.
Jammers are useful in the following: In summary, the significance of a jammer is in three categories: From the work carried out on this project, it is feasible to tap noise from environment for use in engineering systems and possibly energy harvesting in the future.
I envisage noise as a raw material in energy harvesting and in the future noise signature, tracking through Artificial Intelligence will improve security.
Download pdf. Remember me on this computer. Although different cellular systems process signals differently, all cell-phone networks use radio signals that can be interrupted.
Old-fashioned analog cell phones and today's digital devices are equally susceptible to jamming. Disrupting a cell phone is the same as jamming any other type of radio communication.
A cell phone works by communicating with its service network through a cell tower or base station. Cell towers divide a city into small areas, or cells.
As a cell phone user drives down the street, the signal is handed from tower to tower. A jamming device transmits on the same radio frequencies as the cell phone, disrupting the communication between the phone and the cell-phone base station in the town.
It's a called a denial-of-service attack. The jammer denies service of the radio spectrum to the cell-phone users within range of the jamming device. Older jammers sometimes were.
Newer models such as the double and triple band jammers can block all widely used systems AMPS, iDEN, GSM, etc and are even very effective against newer phones which hop to different frequencies and systems when interfered with. As the dominant network technology and frequencies used for mobile phones vary worldwide, some work only in specific regions such as Europe or North America. The power of the 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.
There are concerns that crudely designed jammers may disrupt the functioning of medical devices such as pacemakers. When active in a designated area, such devices will by means of RF interference prevent all pagers and mobile phones located in that area from receiving and transmitting calls.
This type of device transmits only a jamming signal and has very poor frequency selectivity, which leads to interference with a larger amount of communication spectrum than it was originally intended to target. Technologist Jim Mahan said, "There are two types. One is called brute force jamming, which just blocks everything. The problem is, it's like power-washing the airwaves and it bleeds over into the public broadcast area. The other puts out a small amount of interference, and you could potentially confine it within a single cell block.
You could use lots of little pockets of small jamming to keep a facility under control. Itsgenerality combined with its absence of restrictions, makes C a convenient and effectiveprogramming solution for a wide variety of software tasks.
Many applications can besolved more easily and efficiently with C than with other more specialized languages Cx51is not a universal C compiler adapted for the target. It is a ground- up implementationdedicated to generating extremely fast and compact code.
Cx51 provides you with theflexibility of programming in C and the code efficiency and speed of assembly language. The C language on its own is not capable of performing operations such as input andoutput that would normally require intervention from the operating system. Instead, thesecapabilities are provided as the part of the standard library.
Because these functions areseparate from the language itself, C is especially suited for producing code that is portableacross a wide number of platforms.
Since Cx51 is a cross compiler, some aspects of the C programming language and standardlibraries are altered or enhanced to address the peculiarities of an embedded targetprocessor  . It is designed to provide the programmer with the easiest possiblesolution to developing applications for embedded systems, without compromisingperformance or control. It is the best solution for developing code for PIC devices.
It features intuitive IDE,powerful compiler with advanced optimizations, lots of hardware and software libraries,and additional tools that will help to work. Compiler comes with comprehensive help fileand lots of ready-to-use examples designed to get started in no time. Compiler licenseincludes free upgrades and a product lifetime tech support. Power supply board. Switches board. Relay circuit.
Software used in the project: Mikro C compiler. Heart of the project is jammer block, which is explainedin subsequent chapters. The various blocks of cell phone jammer and controller is asshown in Figure 2. Jammer block diagram2. Most digital logic circuits and processors need a 5 volt power supply. To make a 5 volt powersupply, we use a LM voltage regulator IC. The LM is simple to use.
Circuitfeatures are as follow: The IC has features such as safe operating area protection, thermal shut down,internal current limiting which makes the IC very rugged. Output currents up to 1A can be drawn from the IC provided that there is a properheat sink. These microcontrollers are widely used in modern electronicsapplications. A PIC controller integrates all type of advanced interfacing ports andmemory modules. All PIC microcontroller family uses Harvard architecture.
This architecture has theprogram and data accessed from separate memories so the device has a program memorybus and a data memory bus more than 8 lines in a normal bus. This improves thebandwidth data throughput over traditional von Neumann architecture where programand data are fetched from the same memory accesses over the same bus.
Separatingprogram and data memory further allows instructions to be sized differently than the 8-bitwide data word. Thiscontroller is widely used for experimental and modern applications because of its lowprice, wide range of applications, high quality, and ease of availability.
Crystal oscillator isthe natural choice when the accuracy and stability of frequency. The RTC chip uses an internal battery that keeps the time anddate even when the power is off. Each character consists of5x7dot matrix.
Contrast on display depends on the power supply voltage and whethermessages are displayed in one or two lines. For that reason, variable voltage 0-Vdd isapplied on pin marked as Vee. Trimmer potentiometer is usually used for that purpose. Some versions of displays have built in backlight blue or green diodes. When usedduring operating, a resistor for current limitation should be used like with any LE diode. When thecurrent flows through this coil, the coil gets energized.
Initially when the coil is notenergized, there will be a connection between the common terminal and normally closedpin.
But when the coil is energized, this connection breaks and a new connectionbetween the common terminal and normally open pin will be established. Thus whenthere is an input from the microcontroller to the relay, the relay will be switched on. Thuswhen the relay is on, it can drive the loads connected between the common terminals andnormally open pin. Therefore, the relay takes 5V from the microcontroller and drives the Thus the relay acts as an isolation device.
Digitalsystems and microcontroller pins lack sufficient current to drive the relay. For this reason, a driver such as a powertransistor is placed in between the microcontroller and the relay. The operation of this circuit is as follows: The input to the base of the transistor is applied from the microcontroller port pinP1.
The transistor will be switched on when the base to emitter voltage is greater than0. Thus when the voltage applied to the pin P1. When the voltage at the pin P1. Thus the transistor acts like a current driver tooperate the relay accordingly.
Current flowing through the coil of the relaycreates a magnetic field which attracts a lever and changes the switch contacts. The coilcurrent can be on or off so relays have two switch positions and they are double throw changeover switches. Relays allow one circuit to switch and second circuit which can be completely separatefrom the first.
For example a low voltage battery circuit can use a relay to switch a VAC mains circuit. There is no electrical connection inside the relay between the twocircuits; the link is magnetic and mechanical. The coil of a relay passes a relatively large current, typically 30mA for a 12Vrelay, but itcan be as much as mA for relays designed to operate from lower voltages.
Most ICs chips cannot provide this current and transistors usually used to amplify the small ICcurrent to the larger value required for the relay coil. Relays are usually SPDT singlepole double throw or DPDT double pole double throw but they can have many moresets of switch contacts, for example relays with 4 sets of changeover contacts are readily Relays used in our project have got a Coil rating of 12V, and Contact rating of10 Amps.
Power supply. IF section. RF section. The Microcontroller scansthese switches continuously to detect and identify the jamming frequency and jammingduration. Cell phones are designed to add power if they experience low-levelinterference, so the jammer must recognize and match the power increase fromthe phone.
Cell phones are full-duplex devices, which mean they use two separatefrequencies, one for talking and one for listening simultaneously. Some jammersblock only one of the frequencies used by cell phones, which has the effect ofblocking both.
The phone is tricked into thinking there is no service becauseit can receive only one of the frequencies. Less complex devices block only one groupof frequencies, while sophisticated jammers can block several types of networks at once tohead off dual-mode or tri-mode phones that automatically switch amongdifferent network types to find an open signal. Some of the high-end devices block allfrequencies at once and others can be tuned to specific frequencies.
Old fashioned analog cell phones and todaysdigital devices are equally susceptible to jamming. Disrupting a cell phone is thesame as jamming any other type of radio communication. A cell phone works bycommunicating with its service network through a cell tower or base station. As a cell phone user drives downthe street, the signal is handed from tower to tower as shown in Figure 3. Signal handed from tower to towerA jamming device transmits on the same radiofrequencies as the cell phone, disrupting thecommunication between the phone and the cell-phone base station in the town as shown inFigure 3.
Its a called a denial-of-service attack. The jammer denies service of the radiospectrum to the cell-phone users within range of the jamming device. Older jammerssometimes were limited to working on phones using only analog or older digitalmobile phone standards. As the dominant network technology and frequencies usedfor mobile phones vary worldwide, some work only in specific regions such as Europe orNorth America.
Denial of service attackThe power of the jammers effect can vary widely based on factors such asproximity to towers, indoor and outdoor settings, presence of buildings and landscape,even temperature and humidity play a role.
There are concerns that crudelydesigned jammers may disrupt the functioning of medical devices such aspacemakers. Whenactive in a designated area, such devices will by means of RF interference prevent This type of device transmits only a jamming signal and hasvery poor frequency selectivity, which leads to interference with a largeramount of communication spectrum than it was originally intended to target.
One is called brute force jamming,which just blocks everything. The other puts out a small amount ofinterference, and you could potentially confine it within a single cell block. Youcould use lots of little pockets of small jamming to keep a facility under control.
It has a unique identification number for communicating with the cellular base station. The prevention of authorization of call establishment is doneby the software at the base station. This process ofdetection and interruption of call establishment is done during the intervalnormally reserved for signaling and handshaking. When an incoming call arrives, the detector recognizes that number and the callare established for a specified maximum duration, say two minutes. The emergencyusers are also allowed to make outgoing calls.
On leavingthe coverage area of the beacon, the handset must re-enable its normal function. Assuming the beacon system uses a technology with its ownlicense or in the license exempt band , no change to the regulations are neededto deploy such a system. The jammer is predominantly in receiving mode and willintelligently choose to interact and block the cell phone directly if it is within close This selective jamming technique uses a discriminatingreceiver to target the jamming transmitter.
The benefit of such targetingselectivity is much less electromagnetic pollution in terms of raw powertransmitted and frequency spectrum from the jammer , and therefore much lessdisruptive to passing traffic. The jam signal would only stay on as long as themobile continues to make a link with the base station, otherwise there would be nojamming transmission — the technique forces the link to break or unhook andthen it retreats to a passive receive mode again.
This technique has an addedadvantage over Type B in that no added overhead time or effort is spentnegotiating with the cellular network. Although labor intensive to construct, the Faraday cage essentiallyblocks, or greatly attenuates, virtually all electromagnetic radiation from entering orleaving the cage — or in this case a target room.
Emergency calls would be blocked unless there was a way to receive and decodethe 91 1 transmissions, pass by coax outside the room and re-transmitted. It is important tonotice that transmission can never be totally jammed - jamming hinders the reception atthe other end. The problem here for the jammer is that only transmitters can be foundusing direction finding and the location of the target must be a specific location, usuallywhere the jammer is located and this is because the jamming power is never infinite.
Jamming is successful when the jamming signal denies the usability of thecommunications transmission. In digital communications, the usability is denied when theerror rate of the transmission cannot be compensated by error correction. Usually a GenerallyJamming-to-Signal ratio can be measured according to the following Equation.
The above Equation indicates that the jammer Effective Radiated Power, which is theproduct of antenna gain and output power, should be high if jamming efficiency isrequired.
On the other hand, in order to pr event jamming, the antenna gain toward thecommunication partner should be as high as possible while the gain towards the jammer As the equation shows, the antenna pattern, the relationbetween the azimuth and the gain, is a very important aspect in jamming.
Also as we know from Microwave and shown in the equation distance has a stronginfluence on the signal loss. If the distance between jammer and receiver is doubled, thejammer has to quadruple its output in order for the jamming to have the same effect.
Itmust also be noted here the jammer path loss is often different from the communicationspath loss; hence gives jammer an advantage over communication transmitters. Frequency Hopping in GSM is intended for the reduction of fast fading caused bymovement of subscribers. The hopping sequence may use up to 64 different frequencies,which is a small number compared to military FH systems designed for avoidingjamming. For GSM it These cuts are normally caused by propagation losses due to obstacles such as bridges.
Usually another cell could be used to hold communication when the original BTS hasdisconnected. The GSM architecture provides two solutions for this: Handover decisions are made based on transmission quality andreception level measurements carried out by the MS and the BTS. In jamming situationscall re-establishment is probably the procedure the network will take in order to re-connect the jammed TCH. It is obvious that downlink jamming i. In the above table 3. This makes it efficient for the jammer to overpowerthe signal from BS.
To cut an existingconnections, the jamming has to last at least until the call re-establishment timer at theMSC expires and the connection is released, which means that an existing call can be cutafter a few seconds of effective jamming. The maximum number ofrepetitions and the time between them is broadcast regularly. Therefore, the cells in the area should be jammed.
In most cases, theefficiency of a cellular jamming is very difficult to determine, since it depends on manyfactors, which leaves the jammer confused. Thecircuit diagram of cell phone jammer is as shown in Figure 4. Figure 4. Circuit diagram of Cell Phone Jammer Regulated power supply. LCD display. Cell phone jammer schematic. Varying theoutput of the power supply is the recommended way to test a project after having doublechecked parts placement against circuit drawings and the parts placement guide.