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SYLLABUS:
COMMUNICATION SYSTEMS
SIMPLEX
HALFDUPLEX
FULLDUPLEX
MOBILE PHONE HISTORY
MOBILE GENERATIONS
1G
2G
3G
4G
BASICS OF ELECTRONICS
RESISTOR
CAPACITOR
INDUCTOR
DIODE
TRANSISTOR
IC
LED
LCD
OSCILLATOR
POWER SUPPLY UNIT
VOLTAGE
CURRENT
POWER
E.M.F
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POWER SUPPLY CIRCUIT
TRANSFORMER
RECTIFIER
FILTER
REGULATOR
CELLULAR COMMUNICATION
MOBILE COMMUNICATION
WIRELESS COMMUNICATION
INFRARED
BLUETOOTH
VIRUS
MOBILE LOCKS
PCB DIAGRAM
TROUBLE SHOOTING
MOBILE PARTS
GLOSSARY OF TERMS
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COMMUNICATION SYSTEMS:
Simplex:
Simplex communication refers to communication that occurs in one direction
only.
Examples:
Commercial radio broadcast (not walkie-talkies, etc.)
Television broadcast,
Internet multicast.
Half-duplex:
A half-duplex system provides for communication in both directions, but only one
direction at a time (not simultaneously). Typically, once a party begins receiving a signal,
it must wait for the transmitter to stop transmitting, before replying.
Examples:
walkie-talkie (since, it is two-way radio, wherein one must use "Over" or
another previously-designated command to indicate the end of transmission, and ensure
that only one party transmits at a time, because both parties transmit on the same
frequency.)
Full-duplex :
A full-duplex, or sometimesdouble-duplex system, allows
communication in both directions, and,
unlike half-duplex, allows this to happen
simultaneously. Land-line telephone networks are full-duplex, since they allow both
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callers to speak and be heard at the same time. A good analogy for a full-duplex system
would be a two-lane road with one lane for each direction.
Examples:
Telephone,
Mobile Phone, etc.,
MOBILE PHONE HISTORY:
In the year of 1973, a former general manager from the systems division of
Motorola, Dr. Martin Cooper, became who is thought to be the inventor of the first
portable handset. Dr. Cooper was also the first person to make a call using a portable cell
phone.
In New York, he set up a base station with the first
working prototype of a cell phone, the Motorola Dyna-Tac.
He and Motorola took this technology to New York to show
the public.
Later on, in 1977, the cell phone went public and public
testing began. Chicago was the home for the first trials with
2,000 people. After Chicago, there were later trials in
Washington, D.C. and Baltimore, and then it spread to Japan in 1979. Usual technologies
changed in 1988 when the CTIA - Cellular Technology Industry Association - was
formed to lay out realistic goals for cell phone providers. Research for new applications
of development was included.In 1991 the Telecommunications Industry Association set a new standard with the
creation of the TDMA Interim Standard 54.
Cell phones have had quite a long journey. Although there was a great demand for
cell phones, it took 37 years for them to become commercially available in the United
States.
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Wireless service was actually invented almost 50 years ago, so it's hard to believe
that cell phones have only become popular over the past couple of decades. Currently,
there are more than 60 million people who own cell phones.
In the communications world, the Motorola brand brings to mind innovation.
Years of experience engineering portable two-way radio systems led to Motorola's vision
of personal, portable communications. The result was the world's first commercial
portable cellular phone in 1983. Motorola's DynaTAC 8000X phone and the cellular
system behind it changed how the world communicates.
MOBILE GENERATIONS:
0G:
0G refers to pre-cell phone mobile telephony
technology, such as radio telephones that some had in
cars before the advent of cell phones.
One such technology is the Autoradiopuhelin (ARP)
launched in 1971 in Finland as the country's firstpublic commercial mobile phone network.
1G:
1G (or 1-G) is short for first-generation wireless telephone technology, cell
phones. These are the analog cell phone standards that were introduced in the 80's and
continued until being replaced by 2G digital cell phones.
One such standard is NMT (Nordic Mobile Telephone), used in Nordic countries,
Eastern Europe and Russia. Another is AMPS (Advanced Mobile Phone System) used in
the United States.
Antecedent to 1G technology is the mobile radio telephone, or 0G.
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2G:
2G (or 2-G) is short for second-generation wireless telephone technology. It
cannot normally transfer data, such as email or software, other than the digital voice call
itself, and other basic ancillary data such as time and date. Nevertheless, SMS messaging
is also available as a form of data transmission for some standards.
2G is the current generation of full digital mobile phone systems. It transmits
primarily voice but is used for circuit-switched data service and SMS as well. 2G services
are frequently referred as Personal Communications Service or PCS in the US.
2G technologies can be divided into TDMA-based and CDMA-based standards
depending on the type of multiplexing used.
The main 2G standards are:
GSM (TDMA-based), originally from Europe but used worldwide
IS-95 aka cdmaOne, (CDMA-based, commonly referred as simply CDMA
in the US), used in the Americas and parts of Asia
2.5G :
2.5G is a stepping stone between 2G and 3G cellular wireless
technologies. The term "second and a half generation" is used to describe
2G-systems that have implemented a packet switched domain in addition
to the circuit switched domain. It does not necessarily provide faster
services because bundling of timeslots is used for circuit switched data
services (HSCSD) as well.
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While the terms "2G" and "3G" are officially defined, "2.5G" is not. It was invented for
marketing purposes only.
3G:
3G (or 3-G) is short for third-generation mobile telephone technology. The
services associated with 3G provide the ability to transfer both voice data (a telephone
call) and non-voice data (such as downloading information, exchanging email, and
instant messaging).
3G Standards:
3G technologies are an answer to the International Telecommunications Union's
IMT-2000 specification. Originally, 3G was supposed to be a single, unified, worldwide
standard, but in practice, the 3G world has been split into three camps.
UMTS (W-CDMA)
UMTS (Universal Mobile Telephone System), based on W-CDMA technology, is
the solution generally preferred by countries that used GSM, centered in Europe. UMTS
is managed by the 3GPP organization also responsible for GSM, GPRS and EDGE.
FOMA, launched by Japan's NTT DoCoMo in 2001, is generally regarded as the world's
first commercial 3G service. However, while based on W-CDMA, it is not generally
compatible with UMTS (although there are steps currently under way to remedy the
situation).
CDMA2000
The other significant 3G standard is CDMA2000, which is an outgrowth of the earlier 2G
CDMA standard IS-95. CDMA2000's primary proponents are outside the GSM zone in
the Americas, Japan and Korea. CDMA2000 is managed by 3GPP2, which is separate
and independent from UMTS's 3GPP.
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TD-SCDMA
A less well known standard is TD-SCDMA which is being developed in the People's
Republic of China by the companies Datang and Siemens. They are predicting an
operational system for 2005.
List of countries that have deployed 3G:
Australia (W-CDMA) (CDMA2000 1x)
China (CDMA2000 1x)
Germany (W-CDMA)
India (CDMA2000 1x)
Indonesia (CDMA2000 1x)
Japan (W-CDMA, CDMA2000 1x)
Russia (CDMA2000 1x)
Singapore (W-CDMA)
South Africa (W-CDMA in testing)
United Kingdom (W-CDMA)
United States (CDMA2000 1x) (W-CDMA in testing)
BASICS OF ELECTRONICS:
Resistor:
Denoted by R,
Symbol:
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Unit: ohm ()
Function:
It is used to oppose the flow of current or drop the voltage.
Ohm's law
The behavior of an ideal resistor is dictated by the relationship specified inOhm's law:
V= IR
Ohm's law states that the voltage (V) across a resistor is proportional to the current (I)
through it where the constant of proportionality is the resistance (R).
Series and parallel resistors
Parallel resistors:
Resistors in aparallelconfiguration each have the same potential difference (voltage). To
find their total equivalent resistance (Req):
The parallel property can be represented in equations by two vertical lines "||" (as in
geometry) to simplify equations. For two resistors,
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Series resistors:
The current through resistors in series
stays the same, but the voltage across
each resistor can be different. The sum
of the potential differences (voltage) is equal to the total voltage. To find their total
resistance:
Capacitor:
Denoted by C,
Symbol:
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Unit: farad (f)
When an insulator is placed between two conducting parallel plates, then it acts as
a capacitor.
Function:
It acts as a storage device,
It acts as a filter.
Inductor:
Denoted by L,
Symbol:
Unit: Henry.
Function:
It is used to receive the signal and
oppose the change of direction of flow of
current.
Diode:
Denoted by D,
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Symbol:
Function:
Diode acts as a rectifier, that it converts A.C into D.C.
Bridge rectifier is used in the charger circuit for rectification purpose.
It works only on the forward bias, it will not work on the reverse bias. It has a PN
junction layer.
Transistor:
Types of Transistors, NPN, PNP.
Symbol:
NPN : PNP :
It has three terminals, that is Collector, Base, Emitter.It has two PN junction layer.
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EMITTER
It is a region which supplies charge carriers to the other two region hence it is a
heavilyDoped region.
BASE
The base of the transistor is thin and it is lightly doped region.
COLLECTORThe collector of the transistor is always larger than the emitter and base of the
transistorHence the Doping level in intermediate between the heavy doping of emitter and the light
doping of base.Function :
It acts as a switch.
IC :
Integrated Circuit, has many advantages some of them are as follows,
Advantages :
Less in size, Requires low
operating voltage, Low cost.
Dis-advantage :
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W e cant Troubleshoot the problem occurred in the IC.
In case of any damage the whole IC should be replaced.
LED :
Light Eitting Diode.
Symbol:
The operating voltage range for an LED is (1.3-3 Volts).
It gtlows only on the forward bias, it will not work on the reverse bias
It is used in the key pad as a light.
LCD :
Liquid Crystal Display.
It is used in the mobile as a Display.
Oscillator :
It is an electronic device used to produce a repetitive electronic signal. that is,
frequency/pulse.
POWER SUPPLY UNIT:
Voltage:
Difference between two potential point is called as voltage. Its unit is volts(V).
VOLTAGE CONNECTION IN SERIESVoltage is sum of voltage and the current in constant.
Volt = 2V+2 V = 4V
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VOLTAGE CONNECTION IN PARALLELIn this parallel connection voltage remains constant but the current is this
summation of current.
Current:
Flow of electrons in a conducting material in one direction is called as current.
Its unit is Amphere(I).
Power:
Product of voltage and current is called as Power. Its unit is watts.
Power = V*I..
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E.M.F:
Electro Motive Force is the force required to move the electron in a conducting
material
POWER SUPPLY CIRCUIT:
Power supply circuit is also known as Charger circuit.
It requires the following things,
TRANSFORMER
RECTIFIER
FILTER
REGULATOR
TRANSFORMERThe function of transformer is, it will transforms the AC voltage from the primary
coil to the secondary coil without change in the frequency.
There are two type of transformer, they are
Step down transformer
Step up transformer
IN THE STEP DOWN TRANSFORMER
The primary coil winding is greater than the secondary coil.The voltage in the primary will step down to the secondary.
Ex: In a 230V to 20V AC transformer.If 230 V AC is given to the primary of the step down transformer the output from
the secondary will be 20 V AC. But the frequency remains 50Hz.
IN THE STEP UP TRANSFORMERThe primary coil winding is lesser than the secondary coil winding.
The voltage in the primary will step up to the secondary.Ex: If 180 V AC is given to the primary of the transformer than the output voltage
in the secondary will be more than that. But the frequency remains constant.
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RECTIFIERRectifier is used to convert the AC (Alternating Current) to the DC (Direct
Current). Diode acts as a rectifier, here in this power supply circuit, Four diodes D1, D2,D3, D4 are used as a Bridge Rectifier.
The output from the secondary of the transformer is given as the input for the
bridge rectifier.which converts the AC to DC then the output obtained from the BridgeRectifier is a DC Voltage.
FILTER:Filter is used to filter the AC component present in the DC and the output from
the filter circuit is a pure form of DC voltage.
Here Capacitor acts as a filter.
REGULATOR:Regulator an IC which is used to maintain a constant voltage at the output
TYPES OF REGULATOR: Positive Series Regulator
Negative Series Regulator
POSITIVE SERIES:
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7805, 7806, 7809, 7812
Here, the first two number in the IC ,i.e 78 Refers the positive series.
And the Next two Number i.e., 05,06,09,12 refers the voltage level.
NEGATIVE SERIES:
7905,7906,7909,7912.
Here, the first two number in the IC i.e,79 refers the negative series.And the next two number i.e,05,06,09,12 refers the voltage level.
Now we are using only the positive series i.e,7806 voltage regulator
IC for our power supply /charger circuit .So the input voltage is given to the first pin, the second pin is grounded
And the output is taken from the third pin.
POWER SUPPLY CIRCUIT/ CHARGER CIRCUIT :
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CELLULAR COMMUNICATION:
The cellular communication is divided into two sections. They are,
1) Transmission section
2) Receiving section
Transmission section:
Communication from mobile to tower.
During a call the voice signal is received by the MIC. The received analog
signal is converted to electrical signal by MIC. The analog signal cannot be transmitted
and so it is converted to digital signal using ADC converter. The converted digital signal
cannot be transmitted because the transmission range for digital signal is very low. In
order for transmitting the signal, a carrier signal is added with the original signal. This
process is said to be MODULATION. The modulation process is done by RF or Network
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ADC
ADC
MICV
ADC
RF
ADC
TxFilter
ADCAmplifier
PFOADC
AntennaSwitch
Antenna
ADC
TOWER
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IC. The noise signal mixed with the modulated signal is filtered using transmitter filter
(Tx) and then it is amplified. The PFO (Power Filter Oscillator) selects the tower. The AS
(Antenna Switch) selects the user network and transmits the signal to antenna. The
antenna transmits the signal to the tower.
Receiving section:
Communication from tower to mobile.
The receiving section is the reverse process of transmitting section. Here,
the signal from tower is received by mobile antenna. The AS (Antenna Switch) sets the
frequency for the incoming call. The noise in the received signal is filtered by the
receiver filter (Rx Filter) and then it is amplified. The amplified signal is given to the RF/
NW IC for DE-MODULATION i.e., the carrier signal is suppressed and only the original
signal is present at the output of the RF IC. Since it is a digital signal which cannot be
heard by a person, so it is converted to an analog signal by a DAC (Digital to Analog
Converter). Then the analog signal which is in the form of electrical signal is given to the
speaker, it converts the electrical signal to the voice signal.
MOBILE COMMUNICATION
The Switching System
The Switching system is very operative system in which many crucial operations are
conducted, SS systems holds five databases with in it which performs different functions.
If we talk about major tasks of SS system it performs call processing and subscriber
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AntennaSwitch
Antenna
ADC
TOWER
DACSPKR RF IC Amplifier
Rx FilterADC
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related functions. These five databases from SS systems are HLR, MSC, VLR, AUC and
EIR. Lets study each database in detail and learn what functions this little systems
performs.
HLR-HomeLocationRegister:
HLR is database, which holds very important information of subscribers. It is mostly
known for storing and managing information of subscribers. It contains subscriber service
profile, status of activities, information about locations and permanent data of all sorts.
When new connections are purchased, these subscribers are registered in HLR of mobile
phone companies.
MSC- Mobile Services Switching Center:
MSC is also important part of SS, it handles technical end of telephony.It is build to
perform switching functionality of the entire system. Its most important task is to control
the calls to and from other telephones, which means it controls calls from same networks
and calls from other networks. Toll ticketing, common channel signaling, network
interfacing etc are other tasks which MSC is responsible for.
VLR- Visitor Location Register:
VLR performs very dynamic tasks; it is database which stores temporary data regarding
subscribers which is needed by Mobile Services Switching Center-MSC VLR is directly
connected to MSC, when subscribe moves to different MSC location, Visitor location
register VLR integrates to MSC of current location and requests the data about
subscriber or Mobile station ( MS ) from the Home Location Register HLR. When
subscriber makes a call the Visitor location register-VLR will have required information
for making call already and it will not required to connect to Home Register Location -
HRL again.
AUC- Authentication Center:
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AUC is small unit which handles the security end of the system. Its major task is to
authenticate and encrypt those parameters which verify users identification and hence
enables the confidentiality of each call made by subscriber. Authentication center AUC
makes sure mobile operators are safe from different frauds most likely to happen when
hackers are looking for even smallest loop wholes in systems.
EIR Equipment Identity Register:
EIR is another important database which holds crucial information regarding mobile
equipments. EIR helps in restricting for calls been stolen, mal functioning of any MS, or
unauthorized access. AUC Authentication center and EIR- Equipment Identity registers
are either Stand-alone nodes or some times work together as combined AUC/EIR nodes
for optimum performance.
The Base Station System (BSS)
The base station system have very important role in mobile communication. BSS are
basically out door units which consist of iron rods and are usually of high length. BSS are
responsible for connecting subscribers (MS) to mobile networks.All the communication
is made in Radio transmission.The Base station System is further divided in two systems.
These two systems, they are BSC, and BTS. Lets study these two systems in detail.
BTS The Base Transceiver Station:
Subscriber, MS (Mobile Station) or mobile phone connects to mobile network through
BTS; it handles communication using radio transmission with mobile station. As name
suggests, Base transceiver Station is the radio equipment which receive and transmit
voice data at the same time. BSC control group of BTSs.
BSC The Base Station Controller:
The Base Station normally controls many cells, it registers subscribers, responsible for
MS handovers etc. It creates physical link between subscriber (MS) and BTS , then
manage and controls functions of it. It performs the function of high quality switch by
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handover over the MS to next BSC when MS goes out of the current range of BTS, it
helps in connecting to next in range BTS to keep the connection alive within the network.
It also performs functions like cell configuration data, control radio frequency in BTS.
Data moves to MSC-Mobile switching center after BSC done processing it. MSC is
switching center which acts as bridge between different mobile networks.
WIRELESS COMMUNICATION
Wireless communication is used for data transformation with out any wire.
Infra Red
It is a wireless communication for data transfer from mobile to
mobile, which uses IR LED for transmitting and Photo diode for
receiving.
Advantage:
It is a wireless communication process.
Disadvantage:
It uses ray for data transfer, so some of the electronic components may be damaged, since
that ray is harmful for the components.Only can use for short range.
Virus may affect easily.
Infrared light lies between the visible and microwave portions of the electromagnetic
spectrum. Infrared light has a range of wavelengths, just
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like visible light has wavelengths that range from red light to violet. "Near infrared" light
is closest in wavelength to visible light and "far infrared" is closer to the microwave
region of the electromagnetic spectrum. The longer, far infrared wavelengths are about
the size of a pin head and the shorter, near infrared ones are the size of cells, or are
microscopic.
Bluetooth
The system is named after a Danish king Harald Blatand ( Harold
Bluetooth in English), King of Denmark and Norway from 935 and 936 respectively, to
940 known for his unification of previously warring tribes from Denmark, Norway and
Sweden . Bluetooth likewise was intended to unify different technologies like computers
and mobile phones. The Bluetooth logo merges the Nordic runes for H and B.
General information
A typical Bluetooth mobile phone headset
The latest version currently available to consumers is 2.0, but
few manufacturers have started shipping any products yet. AppleComputer, Inc. offered the first products supporting version 2.0
to end customers in January 2005. The core chips have been available to OEMs (from
November 2004 ), so there will be an influx of 2.0 devices in mid-2005. The previous
version, on which all earlier commercial devices are based, is called 1.2.
Bluetooth is a wireless radio standard primarily designed for low power consumption,
with a short range (up to 10 meters) and with a low-cost transceiver microchip in each
device.
It can be used to wirelessly connect peripherals
like printers or keyboards to computers
Versions:
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Bluetooth 1.1
In version 1.1 many errata found in the 1.0B specifications were fixed. There was added
support for non-encrypted channels.
Bluetooth 1.2
This version is backwards compatible with 1.1 and the major enhancements include
Adaptive Frequency Hopping (AFH) , which improves resistance to radio
interference by avoiding using crowded frequencies in the hopping sequence
Higher transmission speeds in practice
extended Synchronous Connections (eSCO) , which improves voice quality ofaudio links by allowing retransmissions of corrupted packets.
Received Signal Strength Indicator (RSSI)
Host Controller Interface (HCI) support for 3-wire UART
HCI access to timing informationfor Bluetooth applications.
Bluetooth 2.0
This version is backwards compatible with 1.x and the major enhancements include
Non-hopping narrowband channel(s) introduced. These are faster but have been
criticised as defeating a built-in security mechanism of earlier versions; however
frequency hopping is hardly a reliable security mechanism by today's standards.
Rather, Bluetooth security is based mostly on cryptography.
Broadcast/ multicast support . Non-hopping channels are used for advertising
Bluetooth service profiles offered by various devices to high volumes of
Bluetooth devices simultaneously, since there is no need to perform handshaking
with every device. (In previous versions the handshaking process takes a bit over
one second.)
Enhanced Data Rate (EDR) of 2.1 Mbit /s.
Built-in quality of service .
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Distributed media-access control protocols .
Faster response times .
Halved power consumption due to shorter duty cycles.
Advantages:
It can be used for long distance.
Data transfer rate is very faster.
Virus :
The codes which cant be read by the mobile phone is called virus.
A mobile phone virus is a computer virus specifically adapted for the cellular
environment and designed to spread from one vulnerable phone to another. Although
mobile phonevirus hoaxes have been around for years, the so-called
Cabir virus is the first verified example. The virus was created by a
group from the Czech Republic and Slovakia called 29a, who sent it
to a number of security software companies, including Symantec in
the United States and Kapersky Lab in Russia. Cabir is considered a "proof of concept"
virus, because it proves that a virus can be written for mobile phones, something that was
once doubted.
SYMPTOMS OF VIRUS INFECTION
Your phone may go into re-starting frequently.
Your phone may operate slower than usual.
Your phone may stop obeying commands or locks up
often.
You may not be able to access some applications in your
phone.
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Some applications on your phone may refuse to work properly.
Unusual error messages may occur often and menus may appear unclear.
Icons which you did not put may crop up and recently opened attachments may
have dual extensions.
Installed antivirus is likely to be disabled or the program may
not start.
New antivirus cannot be installed and even if it is installed, it
will refuse to work until the phone is debugged.
Battery depletion rate is likely to increase because the virus through its malicious
operations will over labor the battery.
These are some common signs of assault by a virus although soft or hardware problemsmay present some of these symptoms.
Mobile Locks
There are two types of locks. They are,
User Lock,
SP Lock.
User Lock is divided into two types they are Keypad lock and Phone lock.
SP lock is the service provider lock it is divided into two types they are PIN and PUK
PIN
Personal identification Number. In the context of wireless devices, the PIN is a code used
in conjunction with a SIM card to complete a call or data transmission. Used for SIM
security. Supplied by the service provider.
PUK
PIN/PIN2 Unblocking Key. Used to unblock the PIN/PIN2. Supplied by the service
provider.
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PCB DIAGRAM
Printed circuit board is the abbreviation for the PCB. There are four layer in the
PCB as shown below,
Layer 1 Antonna Switch
Layer 2
VCO Receiver
Voltage Transmitter
Contro
oscillator FLAH ICS
Layer 3
Layer 4
TROUBLE SHOOTING
Cell phone troubleshooting helps you fix your phone, and it also allows you to figure out
if you have a larger issue with your carrier. Common problems can often be fixed
yourself, or at least it will identify if a repair or replacement might be required. Read on
if you're experiencing issues with your cell phone such as your battery losing power or
the phone ceasing to work after impacting a hard surface.
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PFO IC AS
RX
PX
RFIC
POWER ICCPU
Flash IC
CHARGE
ICSIM IC
FM IC
BLUETOOTH
ICCAMERA
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Dropped Calls
1. If you are having a problem with dropped calls, see if it happens in a particular
geographic location. If so, alert your carrier so that it can begin the process of
providing better coverage in that spot. If calls are being dropped at random, it
could be because of bad weather orbuildings that are blocking your signal. If
neither of these things appears to be the issue and your phone is relatively new,
your SIM card may be malfunctioning. Take your phone to a local dealer to swap
your card.
Water Damage
2. If you've dropped your phone in water, remove the battery and leave the phone in
a cool, dry location with the battery out and the casing left open. Dab a cotton
swab into the phone to remove any excess water and leave the phone to dry. You
can also place the phone in a container of dry rice, which will absorb excess
moisture. After a day, reseat the battery and turn the phone on to see if it works
properly.
Battery Issues
3. Batteries often don't last as long as your phone. If the battery won't hold a charge
for more than an hour or two, then the cheapest fix is to buy a new battery. It's far
less expensive than buying a new phone.
Dropped Phone
4. If you've just watched your phone fly out of your hand onto the sidewalk, knowthat it's not necessarily irretrievably damaged. Simply reseating the battery and
SIM card will often have your phone working like new, minus a few dents and
nicks. If the LCD display is damaged, however, it's often cheaper to buy a new
phone than attempt to have it repaired.
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Can't Receive Calls
5. If your phone won't receive calls, check two things. First, check to see if you can
make outgoing calls. If you can, then verify whether you have a "do not disturb"
option on your phone. You can find this information in the manual that came with
the phone or online (see Resources below). If you can't make outgoing calls, then
contact your service provider. The company may have inadvertently turned your
service off. If you're behind on your payments, the carrier may have suspended
your service.
Samsung Mobile Phone Troubleshooting
Touch Screen or Main Screen Locks
1. A very common problem for many phones is when the Samsung freezes or locks
up while you are using it. There's a very simple formula that will resolve this and
helpyoutroubleshootthisproblemeverytime.
While you have the phone turned on, pull the battery out of the Samsung. Now,
wait for at least 30 seconds to allow the phone to shut down completely (it is like
a mini-computer). After 30 seconds, put the battery back into the phone and put
the battery cover on. Now, hit the power button (or the red end call key) to turn
the phone back on. Your phone should now function normally and the problem
should be resolved.
Insert SIM Card Error
2. The insert SIM card error message can appear on your phone for a number of
reasons. This can even occur on a Samsung if you have the SIM inserted in the
phone. While it can be frustrating, there are some quick fixes to this solutions.
SIM cards rely on "contacts" (metal contacts that establish a connection between
the card and the phone) to function properly. If this connection breaks or is not
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stable, it will cause an Insert SIM error. What you need to do is get to the SIM
card on your phone. This is typically underneath the battery on the device. Once
you get to the SIM card, remove it and re-insert it back into the device, making
sure it firmly locks in place. If you need specific help with this, check out your
user guide or visit Samsung support for assistance.
After you insert it properly, turn on the phone and it should be working now with
full network access.
Cannot Make or Receive Calls
3. Call functionality can experience issues for a variety of reasons, many of which
you can resolve on your own. If you cannot place a call or receive a call on your
Samsung, make sure that you have an active signal on the phone. You will also
want to avoid electrical or radio interference or obstructions, such as bridges,
parking garages or even tall buildings. Again, you will need a solid SIM card
connection and also make sure that your battery is fully charged.
Cannot Hear Callers
4. If you are getting calls on your phone and you cannot hear anyone once you
connected, first try to adjust the volume on the phone. If that does not work, make
sure that you have an active signal on the phone with good coverage. Sometimes,
a headset could cause the problem. If you use one, make sure that it is connected
properly or that you have not hit the mute button on the headset.
No Power
5. If you keep on pressing that power key on your phone but cannot get your phone
on, make sure that you have charged your battery for at least two hours. Some
Samsung phones do not turn on if their battery level is under 25 percent. While
this may be enough juice to run the phone, it cannot power it one. Another check
would be to verify that the battery is in the device securely. Make sure it has
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clicked into place and that the metal contacts on each end are not obstructed in
any way.
Basic Mobile Phone Fault Correction Procedure :
Network Problem
Antenna, Antenna Switch, PFO (RF Power Amplifier), FDK (1st OSC VCO), 13 MHz.
No Network Found
FDK, 13MHz, PFO, CPU.
No Access
Antenna, Antenna Switch, PFO
Set Dead
Battery, Voltage at the Battery
Connector should be more than the Battery ?Voltage, if no then check Power IC, CPU,
Connector.
No Display
Display Connector, Check its track for open, check display.
Gets OFF
(When the phone is switched on, it immediately switches OFF) Battery Loose, Battery
Faulty,
Check Battery Connector, Some humidity(water etc.) may have gone in the set.
Charging Problem
Check the battery voltage written on them. During charging battery contact pins should
contain more voltage then the battery voltage. If These pins contain less voltage then the
power section is faulty. Check the charger, check charger socket, PFO, Power IC, CPU
and the capacitors connected to the Flash.
Dialing problem
Check keypad and its Tracks, Dialer IC, CPU and its Tracks
Ringer Problem
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Check Ringer/Buzzer, Ringer IC (in some models Ringer IC consists of light section
also)
SIM Card Problem
Check SIM Card, SIM Card Socket, ITs Contacts, Track,
EEPROM, Flash Program. In Many handsets fault gets rectified when hot air is given to
the ICs.
Key
If no number is getting dialed then clean the keypad connector, check keypad, tracks.
LED
Check LEDs. These LEDs can be checked like other common LEDs, LED glows when
forward reading is pbtained. Replace the faulty LED. These LEDs are costly their cost
depends on their color. One LED costs around2-35 rupees.
MOBILE PARTS
Mobile parts are divided into four categories. They are as follows,
External parts,
Internal parts,
Fixed components,
Application ICs.
External parts:
The parts which can be remove by hand/soldering is called as external
parts.
Example: Panel, Display, etc,
Internal parts:
The parts which can be removed by blower is called as internal parts.
Example: RF IC,PFO IC, etc,
Fixed components:
The parts which cant be remove in the PCB is called as Fixed
components.
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Example: CPU IC, Flash IC.
Application ICs:
The ICs which are used for entertainment are called Application ICs.
Example: FM IC,B/T IC, etc,
Glossary of Terms :
Batteries
Different types of Batteries
Mobile phones currently employs three battery technologies : Nickel-Cadmium (NiCd) ,
Nickel-Metal Hydride (NiMH) and Lithium-Ion (Li-Ion). While NiCd has been the
standard rechargeable battery used in the wireless industry for years, NiMH and Li-Ion
batteries have gained popularity by improving upon some of the shortcomings of the
NiCd technology.
Nickel-Cadmium (NiCd)
High number of charge/discharge cycles.
Performs well at low temperatures.
Performs best if fully discharged periodically.
Nickel-Metal Hydride (NiMH)
30 percent more capacity over a standardNiCd.
Less prone to memory effect that occurs inNiCd.
Environmentally friendly due to fewer toxic materials used in its manufacturing.
Lithium-Ion (Li-Ion)
Lighter in weight,
Low self-discharge rates, Relatively long cycle life.
Blue Tooth
Blue Tooth is an exciting new technology that allows devices such as mobile phones, LapTop computers, digital cameras and other portable devices to communicate with each
other without using cables to connect them. Blue Tooth is a technology that allows these
devices to communicate with each other using short-range radio waves.
CDMA
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Code Division Multiple Access (CDMA) is one of several digital wireless transmission
methods in which signals are encoded using a pseudo-random sequence which
corresponds to a different communication channel that the receiver also knows and can
use to decode the received signal. CDMA is one of several spread spectrum techniques.
CDMA offers improvements over analog transmission in the areas of reduced call
dropping, battery power conservation, more secure transmission and increased service
options.
Cell
The geographic area encompassing the signal range from one base station (a site
containing a radio transmitter/receiver and network communication equipment). Wireless
transmission networks are comprised of many hexagonal, overlapping cell sites to
efficiently use radio spectrum for wireless transmissions. Also, the basis for the term
cellular phone .
Cellular
In wireless communications,cellular refers most basically to the structure of the wireless
transmission networks which are comprised of cells or transmission sites. Cellular is also
the name of the wireless telephone system originally developed by Bell Laboratories that
used low-powered analog radio equipment to transmit within Cells. The terms Cellular
is also used to refer to non-PCS products and services.
GSM
Global System for Mobile Communications or GSM is the digital transmission technique
widely adopted in Europe and supported in North America for telephone uses. GSM uses
the 1900MHz. GSM uses 900 MHz and 1800MHz in Europe.
MIN
The Mobile Identification Number (MIN) is a unique 24-bit number assigned by the
wireless service provider to each phone it sells or includes in service plans. Unlike an
Electronic Serial Number (ESN), a MIN is changeable because wireless phones may
change hands or phone owners may move to another coverage region,requiring a
different service plan.
MMM
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Mobile Media Mode (MMM) products have the ability to provide information services
such as stock quotes, flight information and reservations, news, sports, weather updates,
and even access to e-mail wirelessly. Check with your local cellular service provider to
find out when services will be available in your area.
PIN
Personal identification Number. In the context of wireless devices, the PIN is a code used
in conjunction with a SIM card to complete a call or data transmission. Used for SIM
security. Supplied by the service provider.
PIN2
Personal identification Number used for the control of Fixed Dial Memory and call
charge metering. Supplied by the service provider.
PUK/PUK2
PIN/PIN2 Unblocking Key. Used to unblock the PIN/PIN2. Supplied by the service
provider.
Roaming
Usinng a wireless phone outside of your service providers local coverage area or home
calling area is reffered to as roaming. Roaming arrangements between service providers
expand the potential area for phone use. Service providers typically charge a higher per-
minute fee for calls placed outside their home calling or coverage areas.
SIM
A Subscriber Identification Module is a Card commonly used in a GSM phone. The card
holds a microchip that stores information and encrypts voice and data transmissions,
making it close to impossible to listen in on calls. The SIM card also stores data that
identifies the caller to the network service provider.
It also stores unique subscriber and user-entered information such as Phone Book, Fixed
Dial Memory and short messages. Supplied by the service provider.
TDMA
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Time Division Multiple Access is one of several technologies used in digital wireless
transmissions that increase the efficiency of the network by allowing a greater number of
simultaneous transmissions. Networks using TDMA assign 6 timeslots for each
frequency channel. Devices using the wireless network send bursts of information that
are reassembled at the receiving end.
Third Generation
The Third Generation (3G) mobile devices and services will transform wireless
communications into on-line, real-time transfer of information, regardless of time and
place. You will be able to send electronic postcards with images, and you can even have a
live video conference using your 3G mobile communication device.
WAP
Wireless Application Protocol is a protocol developed to allow intelligent transmission of
optimized Internet content to wireless phones.
WLL (Wireless Local Loop)
Wireless service system that complete with or substitute for local wireline phone service.
TRACKING
Creating a new way in a circuit is called tracking
If we dint get continuity properly we use tracing
RESISTER TRAKING
Tracking is possible in Resistor
In a service if a single resister fault we use can track
CAPASISTER TRACKING
Tracking is possible in Capasitor when it is connected in series
DIODE
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Tracking is not possible in Diode
INDUCTOR
In Inductor tracking is most impossible
We cannot make tracking for single inductor For Additional Inductor Tracking is possible
Tracking is possible for inductor near transistor