Submitted by:Surbhi Vijh

UE85098BE ECE (II), 7th Sem

“If we continue to develop our

technology without wisdom or prudence,

our servant may prove to be our

executioner”. 

- Omar N. Bradley

WHAT IS A CELL PHONE?

•Combination of the ideas of the telephone

and Radio.

•Extremely sophisticated Radio

•Used to make mobile telephone

calls across a wide geographic area, served

by many public cells, allowing the user to

be mobile.

•Can make and receive telephone calls by

connecting to a cellular network provided

by a mobile network operator.

•Transmit and receive Radio Frequency

(RF) signals in order to communicate, i.e.

use microwave radiation to communicate.

FIRST MOBILE TELEPHONE SYSTEM

One and only onehigh power base station with which allusers communicate.

NormalTelephone

System

Wired connection

THE CELLULAR CONCEPT The core idea that led to today’s system was

the cellular concept.

The cellular concept: multiple lower-power

base stations that service mobile users within

their coverage area and handoff users to

neighboring base stations as users move.

• Instead of one base station covering an

entire city, the city is broken up into cells,

or smaller coverage areas.

•Each of these smaller coverage areas has its

own lower-power base station.

•Each cell is thought of as hexagons or as big

hexagonal grids.

User phones in one cell communicate with

the base station in that cell

Each cell is typically 26 kilometers

CHANGING THE CELL

ADVANTAGE:

In typical analog cell phone system, each

carrier receives about 800 frequencies to

use across a city. With the use of this

concept, different cells (non-adjacent) can

use the same set of frequencies.

WORKING

•When we switch on the mobile phone, it tries for

an SID on the Control channel. If difficult to get link with

the control channel, displays “no service”.

•If the Mobile phone gets the SID, it compares the SID

with the SID programmed in the phone. If both SID

match, the phone identifies the cell.

•The phone also transmits a registration request along

with the SID and the MTSO keeps track of your phone’s

location in a database. MTSO knows in which cell you are

when it wants to ring the phone.

•The MTSO then gets the signal; it tries to find the phone by

looking in its database. Then picks a frequency pair to take

the call.

•The MTSO communicates with the Mobile phone over the

control channel to tell it what frequencies to use. Once the

Mobile phone and the tower switch on those frequencies,

the call is connected.

•When the Mobile phone move toward the edge of the cell,

the signal strength diminishes.

•The two base stations coordinate themselves through the

MTSO. At some point, the Mobile phone gets a signal on a

control channel and directs it to change frequencies. This

will switch the phone to the new cell.

THE FIRST CELL PHONE

•Name- DynaTAC8000X

•Demonstrated by Dr Martin

Cooper of Motorola in 1973

•Commercially available in 1983

•Only 2000 phones available to public

•Weighed 2 kg

•Could store only 30 phone numbers

•Battery needed to be charged for 10 hours

•Talk Time- 1 hour

•Cost- $3,995 only

AN IMPORTANT TECHNOLOGY

Cellular telephony is one of the fastest growing technologies on the planet.

Presently, we are starting to see the third generation of the cellular phones coming to the market.

New phones allow users to do much more than hold phone conversations.

•In the twenty years from 1990 to 2010, worldwide

mobile phone subscriptions grew from 12.4 million to

over 4.6 billion, penetrating the developing

economies and reaching the bottom of the economic

pyramid.

•Mobile or cellular phones are now an integral part of

modern telecommunications.

•In many countries, over half the population use mobile

phones and the market is growing rapidly.

•In some parts of the world, mobile phones are the most

reliable or the only phones available.

•Given the large number of mobile phone users, it is

important to investigate, understand and monitor any

potential public health impact.

ILL EFFECTS OF MOBILES

Specific absorption ratio (SAR) is defined as the

amount of RF (radiofrequency) energy absorbed

per unit mass. It is measured in Watts/Kg and it

is a more useful quantity in that it measures the

amount of energy absorbed by the body in the

course of mobile phone use

This is regarded as one of the safety valves for

mobile phones. In America the SAR of any mobile

phone can not exceed 1.6W/Kg over a gram of

tissue.

The Europeans use the value of 2W/Kg over 10g

of tissues.

Specific Absorption Rate (SAR)

3 sources of

radiation

1.RADIATION EFFECT

A part of the radio waves emitted by a mobile

telephone handset are absorbed by the

human head.

The radio waves emitted by a GSM handset can

have a peak power of 2 watts, and a US

analogue phone had a maximum transmit power

of 3.6 watts.

The best known measure is SAR (Specific

Absorption Rate), which measures the RF power

absorbed by the human body.

2. THERMAL EFFECTS•A typical GSM digital cellular phone operating at a maximum

average power output of about 0.25 watts (W) might results in a

SAR of about 0.5-1.5 W/kg averaged over a gram of tissue.

•This is often associated with a very low rise in brain

temperature (maximum 0.1º C) (Anderson and Joyner 1995;

Vaberg 1997; van Leeuwen et al. 1999).

•This temperature rise increases with the length of the call as

shown in this graph.Note:

Temperature rise is very minimal in the first

few minutes.

Then rises sharply at about 15 minutes

Continued a very gradual increase thereafter

DIELECTRIC HEATING

3. NON- THERMAL EFFECTS

• Some researchers have argued that so-called

"non-thermal effects" could be reinterpreted as

a normal cellular response to an increase in

temperature.

• The German biophysicist Roland Glaser, for

example, has argued that there are several

thermo-receptor molecules in cells, and that

they activate a cascade of second and third

messenger systems, gene expression

mechanisms and production of heat shock

proteins in order to defend the cell against

metabolic cell stress caused by heat.

4. BLOOD BRAIN BARRIER

EFFECTS

Mobile phones open up the Blood Brain Barrier

5. CANCER AND BRAIN

TUMOUR

6. COGNITIVE EFFECTS

7. ELECTROMAGNETIC

HYPERSENSITIVITY

The study confirmed longer (slower) response times to a spatial

working memory task when exposed to RFR from a standard GSM

cellular phone placed next to the head of male subjects, and

showed that longer duration of exposure to RFR may increase the

effects on performance. Several unspecific symptoms during and after use; ranging from

burning and tingling sensations in the skin of the head and

extremities, fatigue, sleep disturbances, dizziness, loss of

mental attention, reaction times and memory retentiveness,

headaches, malaise, tachycardia (heart palpitations), to

disturbances of the digestive system. Reports have noted that all

of these symptoms can also be attributed to stress and that

current research cannot separate the symptoms from

nocebo effects.

8. GENOTOXIC EFFECT

9. SLEEP AND EEG EFFECTSSleep, EEG and waking rCBF(regional cerebral blood flow)  have

been studied in relation to RF exposure for a decade now, and the

majority of papers published to date have found some form of

effect.

Australian research conducted in 2009 by subjecting in

vitro samples of human spermatozoa to radio-frequency radiation

at 1.8 GHz and specific absorption rates (SAR) of 0.4 to 27.5 W/kg

showed a correlation between increasing SAR and

decreased motility and vitality in sperm, increased oxidative stress,

stimulating DNA base adduct formation and increased DNA

fragmentation.

10. DECREASED HIP-BONE

DENSITYMen who routinely wear their cell phones

clipped to their belts have a reduced bone

mineral content (BMC) and bone mineral

density (BMD) in the hip, according to a

study from National University of Cuyo,

Mendoza, Argentina. Electromagnetic

radiation is theorized to be the cause of the

decrease in bone strength.

11. EFFECT ON HEART

•Studies suggest, the strength of these fields will

not affect ordinary heart rhythm or function.

•Can present a danger to those with an implanted

pacemaker, internal defibrillator or similar

device.

•Problems most likely to arise when pacemakers

and defibrillators are being programmed or reset

by medical staff.

•Recommended that keep cell phones and media

players at least six inches from the generator

(implanted device).

Cell phones may interfere with pacemakers

SOME STUDIES•March 2003, a study in the International Journal of Oncology suggested that mobile phone users had a 30% increased risk of brain tumours - mainly accoustic neuromas.

•Short exposure to Mobile phone radiation - two hours - has been reported in 2003 to destroy cells in parts of the brain important for memory, movement and learning, and could possibly conceivably premature onset of illnesses such as Alzheimers.

•In October 2004, scientists at the Karolinska Institute in Stockholm gave a new warning about mobile phone radiation and brain tumours - accoustic neuromas.

•Cellular changes demonstrated at non-thermal

levels

•Autism may be Linked to Electromagnetic

Radiation Levels In Mother’s Bedroom During

Pregnancy

Body Voltage Levels

Median Body Voltage Level in Mom’s Bed During Pregnancy*

Value Range

Neurologically Impaired Children 1,872

milliVolts   

(380-6,040)

Healthy Group  224  milliVolts   (12-480)

Result: 8.4x Higher Body Voltage Levels in Mom’s with Neurologically

Impaired Children

*Note research shoes whatever the Body Voltage of the Mom, it is even

higher in the foetus.

Body Voltage of Child in Current Bed Location

Value Range

Neurologically Impaired Children 1,028 

milliVolts    

(420-4,900)

Healthy Group  120 milliVolts   

   

(0-230)

Result: 8.5x Higher Body Voltage in Neurologically Impaired Child’s

Sleeping Location

Microwave Exposure

Microwave Power Density in Sleeping Location

mw/sq.

meter

Range

Neurologically Impaired

Children

290 (110-1,710)

Healthy Group  14 (0-67)

Result: 20.7x higher microwave power density in

mom’s sleeping location in cases where children were

neurologically impaired.

HEALTH HAZARDS OF BASE

STATIONS

SOME STUDIES

•Great cancer risk increase in the

vicinity of a GSM base station

•New Austrian research confirms

health effects of base station

radiation

•French study found base stations

affected health negatively

SAFETY AND STANDARDS

•There are many proposed national and

international standards

•That of the International Commission for Non-

Ionizing Radiation Protection (ICNIRP) is the

most respected one

•Has been adopted so far by more than 80

countries.

• For radio stations, ICNIRP proposes two

safety levels: one for occupational exposure,

another one for the general population

ICNIRP Reference Levels

Device FCC /OSHA Typical Comment

Cell phone / mobile phone / PDA / Scanner

1.6 W/kg over 1 gram of body mass, 4 W near hands, wrists, feet and ankles

0.1mW to 0.5W at the handset

0.5 W if user is at edge of the cell, 0.1mW if user is near a cell tower +

Therefore, more the number of towers, less

will be power transmitted by your cell phone

Safety Limits – Proximity devices

PRECAUTIONS

•DO NOT SLEEP WITH MOBILE

PHONE UNDER THE PILLOW

•Prefer SMS over

calls

•AVOID LIVING NEAR BASE

STATIONS

Cell Phone EMF Radiation Detector

Cell Phone & Small Appliance EMF Anti-Radiation Protector

Strip

Cell-Shield Cell Phone Case with Radiation Shield (Model A)

Cell Phone Radiation Shield - Anti-Radiation Shield Sticker for

Cellular Phones

RF3 ENVi Natural Wood Stereo Earbud Cell Phone Headset with

3.5 mm Jack

Airtube Wireless "Single" Ear Hook Headphone Radiation Free

Fits Both 2.5mm and 3.5mm Jack , Compatible with Ipod, Iphone

& Blackberry and All Cellphones with 2.5mm and 3.5mm Jack

REFRENCES1. http://www.freewimaxinfo.com/mobile-communication-technologies.html

2. http://en.wikipedia.org/wiki/Mobile_phone_radiation_and_health

3. http://www.scribd.com/doc/47580455/mobile-communication

4. http://electronics.howstuffworks.com/cell-phone1.htm#

5. http://electroschematics.com/5231/mobile-phone-how-it-works/

6. http://www.articlesbase.com/communication-articles/harmful-effects-of-cell-

phone-radiations-205163.html

7. http://info.cancerresearchuk.org/healthyliving/cancercontroversies/

mobilephones/

8. BMC Genomics 2008, 9:77

9. electromagnetichealth.org

10.http://www.lawyersclubindia.com/forum/Re-Re-How-to-stop-the-cell-Mobile-

tower-in-residential-area-4455.asp?1=1&offset=2

11.http://www.mensxp.com/health/live-healthy/3921-how-to-counter-bad-effects-of-

mobile-phone-radiation.html

THANK YOU