Debre Markos University

8/17/2019 Debre Markos University

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CERTIFICATE/DECLARATION

This is to certify that the project report entitled on cell phone jammer design is being

submitted by

Name Id number

1. Addisu Yeshiwas TER!"#$%&

!. Amare Tiruneh TER1''(%&

". )he*ol +hitawa TER""$"%&

&. ,ihret ,ebratu TER!(1%%&

$. Admasu -,icheal TER1"1%"

In partial fulfillment for the award of the /egree of 0achelor of +cience in Electrical

Engineering to /ebre ,ar*os 2ni3ersity is a record of bonafied wor* carried out under

my guidance and super3ision.

The results embodied in this project report ha3e not been submitted to any other

2ni3ersity or Institute for the award of any /egree or /iploma.

4uide Name

+ignature555. -ead of the /epartment

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ACKNOWLEDGEMENT

7or our document of the semester project to arri3e at its final stage8 many indi3iduals

gi3e us their forwarding contribution since the beginning.

9rimarily8 we would li*e to gi3e glory to 4od and the :irgin ,ary without which the

completion of this project would ha3e been unthin*able.

+econdly we would li*e to e;press my special than*s of gratitude to our guide ad3isor

Yohannes Tesfaye who ga3e us the golden opportunity to gi3e her profound guidance in

this project on the ,obile jammer8 which also helped us in doing a lot of project and we

came to *now about so many new things.

7inally we also gi3e great than* to those gi3ing suggestion about how to do cell phone

jammer design.


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Contents

)ERTI7I)ATE/E)?ARATIBN555555555555555555555 "

A)CNB


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".1 amming Techni@ues555555555555555555555555 1#

".1.1 +poofing555555555555555555555555555.. 1#

".1.! +hielding Attac*s555555555555555555555555. 1#

".1.". /enial of +er3ice555555555555555555555555 1#

".! /esign parameters and specifications55555555555555555.. 1(

".!.1 The 7re@uency 0and55555555555555555555555.. 1(

".!.! /istance to be jammed F/G55555555555555555555.. 1(

".!." 7ree +pace ?oss5555555555555555555555555. 1(

".!.& ammingHto=signal ratio +J555555555555555555551'

"." 9ower calculations555555555555555555555555.. !%

".& 9arts of jammer de3ices5555555555555555555555.. !%

".$ 9ower supply555555555555555555555555555 !%

".$.1 Rectification55555555555555555555555555. !1

".$.! The 7ilter555555555555555555555555555.. !1

".$." Regulator555555555555555555555555555.. !1

".$.& Amplifier555555555555555555555555555.. !1

". Noise generator55555555555555555555555555. !!

".# ?) Tuned )ircuit5555555555555555555555555. !!

".( Transmitting Antenna55555555555555555555555.. !"

)-A9TER 7B2R55555555555555555555555555. !&

RE+2?T+ AN/ /I+)2++IBN BN )E?? 9-BNE A,,ER55555555.. !&

&.1 9rinciple operation on modified circuit diagram5555555555555.. !$

&.! +imulation Result5555555555555555555555555 !

)-A9TER 7I:E55555555555555555555555555.. !#

)BN)?2+IBN K RE)B,,EN/ATIBN55555555555555555 !#

$.1 )onclusion5555555555555555555555555555.!#

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$.! Recommendation5555555555555555555555555.. !(

RE7EREN)E+55555555555555555555555555.

?ist of table

Table !.1 ,cc in Ethiopia55555555555555555555.

Table !.! 4+, system fre@uency55555555555555555

?ist of figure

7ig ".1 ?) Tuned )ircuit5555555555555555555

7ig ".! 0loc* diagrams of cell phone jammer55555555555

7ig &.1 Initial ammer )ircuit /iagram5555555555555

7ig &.! ,odified circuit diagram555555555555555

7ig &." jammer out put on simulation55555555555555

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List of abbreviation

R Resistor

? Inductor

) )apacitor

I) Integrated )ircuit

/) /irect current

4+, 4lobal +ystem for ,obile )ommunication

/)+ /igital )ellular +ystem

0T+ 0ase +tation Transcei3er

+NR +ignal to Noise Ratio

A Anti amming

,)) mobile country code

7+C 7re@uency shift *eying

4,+) gate way mobile switching center

,N) ,obile networ* code

0+) 0ase station controller

/B+ /enial of ser3ice

T/,A Time di3ision multiple access

,+) ,obile switching center

,+ ,obile station

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CHATER ONE

INTROD!CTION

"#" Ba$%&ro'n( of t)e st'(*

The technology being used by this de3ice is 3ery simple. The mobile phone

transmission is being bloc*ed and interfered by Radio fre@uency which creates high

noise. The fre@uency being generated by the jamming de3ice jams the signal being

generated by the cell tower. ,obile jammers bloc* mobile phone use by sending out

radio wa3es along the same fre@uencies that mobile phones use. This causes enough

interference with the communication between mobile phones and communicating

towers to render the phones unusable.


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information about the concerned uplin* channel Fby the mean of a training se@uence or

blind methodsG8 downlin* processing encounters more se3ere difficulties6 no

information about the downlin* channel is a3ailable at the base station prior to data

transmission.


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jam a cellular phone. ,ost jamming de3ices can jam only one fre@uency.

"#1 Met)o(o-o&* of st'(*

The proposed solution is in software8 in which only an authori>ed person can access its

cell phone in an allocated time. To pro3ide the re@uired solution8 we need to de3elop

fre@uency domain based on altered fre@uency band and altering de3ice signal below the

range of signal generated by jammer through modulation to adapti3ely jam the target

region.

A noise generator is a circuit that produces electrical noise Frandom8 non=deterministic

signalG. Noise generators are used to test signals for measuring noise figure8 fre@uency

response8 and other parameters8 it can also be used for the generation of random

numbers. +e3eral noise generation methods include6

-eated resistors8 ener diodes and gas discharge tubes. This project utili>es ener diode

noise method and also incorporates industrial noise which is sensed by Electret

microphones with high sensiti3ity. In

)ommon jammer designs8 such as 4+, '%% and 4+,1(%% ammer.

"#2 T)eoreti$a- fra,e 3or%

The control framewor* used in the study follows the input H process H output

relationship. amming de3ices are connected to the appropriate input module of the8

3oltage source8 ?, $$$), timers and transistor while output de3ices are connected to

the designated output module of the oscilloscope. Input K output de3ices are processedthrough the transistor to the desired noise signal of the output de3ices.

1.7 Scope an( -i,itations of t)e st'(*

)ell phones are full=duple; de3ices8 which mean they use two separate fre@uencies8 one

for tal*ing and one for listening simultaneously. +ome jammers bloc* only one of the

fre@uencies used by cell phones8 which has the effect of bloc*ing both. The phone is

tric*ed into thin*ing there is no ser3ice because it can recei3e only one of the

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CHATER TWO

LITERAT!RE RE4IEW

)ommunication jamming de3ices were first de3eloped and used by military. This

interest comes from the fundamental area of denying the successful transport of the

information from the sender to the recei3er. Nowadays the mobile jammer de3ices are

becoming ci3ilian products rather than electronic warfare de3ices8 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 disrupti3e has increased. These

places include worship places8 uni3ersity lecture rooms8 libraries8 concert halls8 meeting

rooms8 and other places where silence is appreciated.

+#" Mobi-e $o'ntr* $o(e In Et)io0ia

A mobile country code F,))G is used in combination with a mobile networ* code

F,N)G Falso *nown as a ,)) ,N) tupleG to uni@uely identify a mobile networ*

operator FcarrierG using the 4+,.

Table !.1 ,)) in Ethiopia

,)) ,N) 0rand Bperator status 0andsF,-G

" %1 ET-=,TN Ethio Telecom Bperational 4+, '%% 4+,

1(%%

+#+ Overvie3s on $e-- 0)one 5a,,er

This ,obile 9hone ammer is using 4+, to jam the fre@uencies. 4lobal +ystem for

,obile )ommunications F4+,G 4+, is an acronym for 4lobal +ystem for ,obile

communications. It accounts for about #%O of the global mobile mar*et. 4+, uses a

3ariation of time di3ision multiple access FT/,AG. 4+, pro3ide for data and 3oice

communication throughout a wide geographic area. 4+, system di3ided large

geographic area in Ethiopia into small radio areas FcellsG that are interconnected each

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other F,icrowa3e connectionG. Each cell co3erage area has one or se3eral transmitter

that communicates with mobile telephone within its co3erage area.

In 4+, system the mobile handset is approach to mobile phone jamming system thatcalled ,obile station F,+G. A cell is formed by the co3erage area of 0ase Transcei3er

+tation F0T+G which ser3es the ,+ in its co3erage area. +e3eral 0T+ together are

controlled by one 0ase +tation )ontroller F0+)G. The 0T+ and 0+) together form 0ase

+tation +ubsystem F0++G.The combed traffic of the mobile station in their respecti3ely

cells is routed through a switch called ,obile +witch )enter F,+)G.)onnection

originating or terminating from e;ternal telephone are handle by a dedicated 4ateway

,obile +witching )enter F4,+)G.

+#. Base Station Center 6BSC7

0+) is a high capacity switch with radio communication and mobility control

capabilities. The function of 0+) is including radio channel allocation8 location update8

and hando3er8 timing ad3ance8 power control and paging.

+#.#" Main f'n$tions of Base station $enter

)ontrol the handset between its 0T+s.

+witch traffic and signaling tofrom the 0T+s and ,+).

,anage the interconnection between 0T+s ,+)

+#1 Base Station Trans$eiver 6BTS7

A 0T+ is radio transcei3ers stations that communicate with the mobile station. Its bac*

end to the 0+). ,ore 0T+ is usually placed at the center of a cell. Its transmitting

power defines the si>e of a cell. Each radio has single fre@uency. The 4+, system uses

T/,A to split a fre@uency into time slots.

+#8 GSM o0eration in Et)io0ia

Table below contains the fre@uency bands for 4+, system. To a3oid the fractions

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infre@uencyP the companies of mobile communication use the abbre3iation absolute

radio fre@uency channel number FAR7)NG to define the uplin* and downlin* at the

same time.

Table !.! 4+, system fre@uency

2p lin* /own lin*

4+,'%% ((%='1&,- '"$='%,-

4+,1(%% 1#1%=1#($,- 1(%$=1((% ,->

CHATER THREE

MATERIAL AND METHODS OF CELL HONE 5AMMER

)ell phones are full=duple; de3ices8 which mean they use two separate fre@uencies8 one

for tal*ing and one for listening simultaneously. +ome jammers bloc* only one of the

fre@uencies used by cellphones8 which has the effect of bloc*ing both. The phone is

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tric*ed into thin*ing there is no ser3ice because it can recei3e only one of the

fre@uencies. A cell phone jammer is an instrument used to pre3ent cellular phones from

recei3ing and transmitting the mobile signals to a base station.


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.#+ Desi&n 0ara,eters an( s0e$ifi$ations

0ased on the abo3e8 our de3ice which is related to the /B+ techni@ue is transmitting

noise on the same fre@uencies of the two bands 4+, '%% ,->8 and 4+, 1.( 4->

F*nown also as /)+ 1(%% bandG.

4+, 1(%% 1(%$=1((% ,->

Therefore8 our goal is to disrupt communication o3er downlin* fre@uencies only

.#+#+ Distan$e to be a,,e( 6D7

This parameter is 3ery important in our design8 since the amount of the output power of

the jammer depends on the area that we need to jam. ?ater on we will see the

relationship between the output power and the distance /. Bur design is established

upon /1% meters for 4+, 1(%% band and /!% meters for 4+, '%% band. As the

distance increases8 the total we need to jam a mobile phone increases proportionally. As

the distance increases8 the total power we need to jam a mobile phone increases

proportionally.

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.#+#. Free S0a$e Loss

As our jamming signal tra3els through the air8 it will attenuate. There are some factors

affecting the magnitude of 7+?. These factors can be seen in the calculation formula of

7+?.

7 Fd0G "!.&&S!%log Fdistance in *mG S!% log Ffre@uency in ,->G Fin our calculationP

d is in *m and f is in ,->G. The ma;imum free space loss Fworst case 7G happens when

the ma;imum fre@uency is used in e@uation abo3e. 2sing 1((% ,-> and /1% meters

gi3es6

7 Fd0G "!.&&S!%log F%.%1G S!% log F1((% ,->G $( d0

.#+#1 5a,,in&:to;si&na- ratio


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In contrast8 if we ha3e a mobile further from the base station it will recei3e a power

much lower than the pre3ious case and this will be best case for jamming as it does not

need high power to jam.

.#. o3er $a-$'-ations

-ere in this part8 we want to calculate the needed power in order to jam a cell phone

with in a distance of 1% m for /)+ and !% m for 4+, '%%. 7rom the abo3e

considerations we shall calculate for the worst case.

SNRmin 'd08Smax =1$d0m in order to be sure we will ha3e a jamming in

e3erywhere as6

J r Fammer power at mobile recei3erGU S

max = SNRmin

J r U=!&d0m

ammer output power jr S

F dBm

Therefore output power=!& d0mS$(d0 "&d0m so8 this power will be needed for the

worst case for jamming the specified region

.#1 arts of a,,er (evi$es

ammer is the act of intentionally directing electromagnetic energy at a communication

system to disrupt or pre3ent signal transmission. The 4+, ammer is a de3ice that

transmit signal on the same fre@uency at which the 4+, system operates8 the jamming

success when the mobile phones in the area where the jammer is located couldnt ma*e

or recei3e call phones.

Electronically spea*ing8 cell=phone jammers are 3ery basic de3ices. The simplest just

ha3e an onoff switch and a light that indicates itMs on. ,ore comple; de3ices ha3e

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switches to acti3ate jamming at different fre@uencies. )omponents of a jammer include6

.#8 o3er s'00-*

The proposed design re@uires a S1$ :olts /) +upply. This is used to supply the other

sections with the needed 3oltages. Any power supply consists of the following main

parts

.#8#" Re$tifi$ation

Rectification is the part use to con3ert the A) 3oltage to a /) one. e the ripple in the output.

.#8#. Re&'-ator

Regulator is used to pro3ide a desired /)=3oltage. The 3oltage source in a circuit may

ha3e fluctuations and would not gi3e the fi;ed 3oltage output. The 3oltage regulator I)

maintains the output 3oltage at a constant 3alue. Regulator 9ro3ides S1$: regulated

power supply. )apacitors of suitable 3alues can be connected at input and output pins

depending upon the respecti3e 3oltage le3els.

Regulator is the final part of the power supply used to pro3ide the desired

constant /) output that is basically independent of the input 3oltage.

.#8#1 A,0-ifier

The essential role of this acti3e element is to magnify an input signal to yield a

significantly larger output signal. The amount of magnification Fthe forward

gainG is determined by the e;ternal circuit design as well as the acti3e de3ice.

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The term power amplifier is a relati3e term with respect to the amount of power

deli3ered to the load andor pro3ided by the power supply circuit. In general the

power amplifier is the last MamplifierM. Br actual circuit in a signal chains Fthe

output stageG and is the amplifier stage that re@uires attention to power

efficiency. There are four basic types of electronic amplifier6 the 3oltage

amplifier8 the current amplifier8 the trans=conductance amplifier8 and the trans=

resistance amplifier. A further distinction is whether the output is a linear or

nonlinear representation of the input. Amplifiers can also be categori>ed by their

physical placement in the signal chain.

:oltage amplifier H This is the most common type of amplifier. An input 3oltage is

amplified to a larger output 3oltage. The amplifierMs input impedance is high and the

output impedance is low.

)urrent amplifier H This amplifier changes an input current to a larger output current.

The amplifierMs input impedance is low and the output impedance is high. Trans=

conductance amplifier H This amplifier responds to a changing input 3oltage by

deli3ering a related changing output current.

.#2 Noise &enerator

To generate noise signal8 we used the ener /iode operated in re3erse mode.

Bperating in the re3erse mode causes what is called a3alanche effect8 which

causes wide band noise. This noise is then amplified and used in our system.

9roduces random electronic output in a specified fre@uency range to jam the

cell=phone networ* signal

.#? LC T'ne( Cir$'it

In electronics an ?) circuit8 also called a resonant circuit tuned circuit8 consists of two

electronic components connected togetherP an inductor8 represented by the letter ?8 and

a capacitor8 represented by the letter ). The circuit can act as an electrical resonator8 an

electrical analogue of a tuning for*8 storing energy oscillating at the circuitMs resonant

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fre@uency.?) circuits are used either for generating signals at a particular fre@uency8 or

pic*ing out a signal at a particular fre@uency from a more comple; signal.

7ig ".1 ?) Tuned )ircuit

Any practical implementation of an ?) circuit will always include loss resulting from

small but non=>ero resistance within the components and connecting wires. The purpose

of an ?) circuit is usually to oscillate with minimal damping8 if a charged capacitor is

connected across an inductorP charge will start to flow through the inductor8 building up

a magnetic field around it and reducing the 3oltage on the capacitor. E3entually all the

charge on the capacitor will be gone and the 3oltage across it will reach >ero. -owe3er8the current will continue8 because inductors resist changes in current.

.#@ Trans,ittin& Antenna

A proper antenna is necessary to transmit the jamming signal. In order to ha3e optimal

power transfer8 the antenna system must be matched to the transmission system. In this

project8 we used two 1& wa3elength monopole antennas8 with $% V input impedance so

that the antennas are matched to the system.


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7ig ".! 0loc* diagrams of cell phone jammer

CHATER FO!R

RES!LTS AND DISC!SSION ON CELL HONE 5AMMER

The objecti3e of our project is to pro3ide the ultimate solution in any area where

cellular communications fre@uently cause nuisance either by loud incoming call rings or

resulting loud telephone con3ersations.

This was the initial circuit diagram which we get from internet8 its gi3es us '%%,-

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fre@uency noise signal on simulation .0ut as we want to build dual band cell phone

jammer because of dual bands is used in Ethiopia .+o we ha3e modified the circuit to

get dual band fre@uency signal. 7irst band '%% ,->

+econd band 1.( 4->

7ig &.1 Initial ammer )ircuit /iagram

,obile jammer is a de3ice which disturbs the communication between the mobile base

station and mobile e@uipment by transmitting the noise signal at the fre@uency8 on

which both are trying to communicate with each other. 7irstly8 jammers were in3ented

to pre3ent the communication between the army personnels of enemy and in time

they de3eloped into ci3ilian life. The technology behind the mobile jammer is

o3erpowering the mobile phone signals and decreasing the +NR F+ignal to Noise

RatioG for mobile communication.

The ,odified circuit diagram is shown below

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7ig &.! ,odified circuit diagram

1#" rin$i0-e o0eration on ,o(ifie( $ir$'it (ia&ra,

A L)ell ammerD is just way of saying L/irty TransmitterD which happens to

transmit within the )ellular 9hone 0ands. Reality is the dirtier the better.

LM888CM Ti,er; The output of the ?,$$$ timer has a fre@uency which is

proportional to the input 3oltage8 thus8 we can control the output fre@uency by

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changing the input 3oltage.

4enerates the radio signal interfere with the cell phone signal .?,$$$ timer (

pin I) simply ma*es a noise. Its coupled through )& WelectrolyticX to modulate

the 0)$ transistor oscillator.


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1#+ Si,'-ation Res'-t

The result was being obtained by simulating the abo3e circuit diagram8 the final

result FoutputG shown below6

7ig &." jammer output on simulation

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CHATER FI4E

CONCL!SION RECOMMENDATION

8#" Con$-'sion

In this project8 which turned out to be a full success8 we designed a de3ice that stops

9hone ringing. This de3ice could be used in places where ringing is not desired at

+pecific times8 as these ringing may disturb people in such places. The designed /e3ice

wor*s in dual band. It jams both the 4+, '%% and 4+, 1(%% bands. The /e3ice was

able to jam the two main cell phone carriers in Ethiopia.

The project could be ended up with all stages howe3er test part could be completed

partially. 7irstly8 main logic and technology behind a mobile phone jammer were

determined clearly and this logic was based on a mathematical bac*ground.


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+ome effects such as multipath fading which are not ta*en into account in appro;imate

calculation. After some theoretical part8 design components were determined for a '%%

8#+ Re$o,,en(ation

According to our project result is not full success8 we suggest that the student

FhesheG who want continue with this project8 they should ha3e more techni@ues

of jamming the signals8 also in case of Integrated circuit FI)G use the one which

is capable for generating (%% ,-> and abo3e. Also use e;actly components that

are in your circuit.

7or all you want to de3elop this project you can do using micro controller8

ardinuo software implementation.

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REFERENCES

W1X www.-ow+tu

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Debre Markos University