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.
2. WHAT IS A CELL PHONE?
•Combination of the ideas of the telephone and
Radio.
•Extremely sophisticated Radio
3. •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.
4. FIRST MOBILE TELEPHONE SYSTEM
One and only one
high power base
station with which all
users communicate.
Entire Coverage
Area
Normal
Telephone
System
Wired connection
5. 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.
6. • 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.
7.
8. User phones in one cell communicate with the base
station in that cell
Each cell is typically 26 kilometers
10. 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.
11. 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.
12. •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.
13.
14. 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
15. 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.
16. •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.
20. 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)
21.
22. 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.
23. 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
25. 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.
26. 4. BLOOD BRAIN BARRIER EFFECTS
Mobile phones
open up the
Blood Brain
Barrier
29. 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.
30. 8. GENOTOXIC EFFECT
9. SLEEP AND EEG EFFECTS
Sleep, 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.
31. 10. DECREASED HIP-BONE DENSITY
Men 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.
32. 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).
34. 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.
35. •Cellular changes demonstrated at non-thermal levels
•Autism may be Linked to Electromagnetic Radiation Levels
In Mother’s Bedroom During Pregnancy
36. 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
37. 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.
39. 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
41. • 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
43. 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
54. 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
