STUDY OF RADIOACTIVITY DUE TO BAND

SIGNALS FROM MOBILE TOWER

SEMINAR CO-ORDINATOR

ANIL JAYAMOHAN

RENJITH A

PRESENTING BY

MUNEESH NK

REG.NO 19123419

DATED ON 24-09-2014

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INTRODUCTION

RADIATION FROM CELL TOWERS

MOBILE PHONE TOWER

RADIATION

RADIATION PATTERN OF THE ANTENNA

POWER DENSITY AND RADIATION LEVEL

THEORETICAL AND MEASURED RADIATED

POWER

RADIATION MEASUREMENT DEVICE

REALIZATION OF COMPLIANCE DISTANCE

RADIATION SHIELD

BIOLOGICAL EFFECTS OF CELL TOWER

RADIATION ON HUMAN BODY

CASE STUDY

RADIATION NORMS ADOPTED IN INDIA AND

OTHER COUNTRIES

CONCLUSION

CO

NTEN

TS

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INTRODUCTION

As Cell phone technology has revolutionized , Large number of BTSs/towers is deployed

More than 50 crore cell phone users and nearly 4.4 lakh cell phone towers in India

Study of cell tower radiation is essential in daily life.

Presence of large number of antennas on single tower with multiple carriers

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Radiation from cell towers

Antennas on Cell tower transmit in the

frequency range of:

869 - 890 MHz (CDMA)

935 - 960 MHz (GSM900)

1805 – 1880 MHz (GSM1800)

2110 – 2170 MHz (3G)*

Cell towers transmit radiation 24x7Mobile

People living within 100’s of meters from the tower will

receive 10,000 to 10,000,000 times stronger signal than

required for mobile communication.10/24/201

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Mobile phone tower

Mobile tower have electronic

equipment and antennas.

They receive and transmit

radiofrequency (RF) signals.

The antennas need to be high

enough , so they can adequately

cover the area.

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phone operators divide a region in large number

of cells, and each cell is divided into number of

sectors

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RADIATION

Radiation is a form of energy on the move.

Radiation is electromagnetic in nature

There are two types of radiation:

1. Ionizing radiation

2. Non-ionizing radiation (NIR)

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RADIATION PATTERN OF THE

ANTENNA

The radiation pattern of a cell tower antenna is defined

by its lobes.

Radiation will be highest from the primary lobes in the

horizontal direction.

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Radiation Pattern of Antenna

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POWER DENSITY AND RADIATION

LEVEL

The power density at any distance from an isotropic antenna

is the transmitter power divided by the surface area of a

sphere at that distance.

The surface area of the sphere increases by the square of the

radius.

Equation

S = PG/4R2

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Compliance distance recommended by ICNIRP

(based on ITU K.70 fact sheet formula)

Radio Frequency Range

General Public Exposure

General Public Exposure

1 to 10 MHz r = 0.10 √eirp×f r = 0.129√erp×f

10 to 400 MHz r = 0.319 √eirp r = 0.409 √erp

400 to 2000MHz r = 6.38 √eirp/f r = 8.16 √erp/f

2000 to 300000MHz r = 0.143 √eirp/f r = 0.184

√erp/f

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GSM cell tower power density levels –

percentiles

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Theoretical and measured radiated power

To measure the power at a distance R from the transmitting cell

tower antenna,

Equation

At 887 MHz (tower transmitting frequency in CDMA), Pr = -3.2 dBm.

At 945 MHz (tower transmitting frequency in GSM900), Pr = -3.8 dBm.

At 1872 MHz (tower transmitting frequency in GSM1800), Pr = -9.7 dBm

Power density for all these frequencies is 31,800 μW/m2. 10/24/2014

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RADIATION MEASUREMENT DEVICE

Measurement of received power using dipole antenna and spectrum analyzer

Measured power using spectrum analyzer showing multiple bands

REALIZATION OF COMPLIANCE DISTANCE

This exercise was done to

realize compliance zone for

a particular BTS/ antenna

Transmitted power, antenna

gain, frequency, antenna

height, tilt etc. were vary to

observe dependency of

these factors on compliance

distance.

Observed Power Density

(Watt/m2)

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Distance(m)

Power Density(Watt/m2)

GSM antenna with 4 carriers in one sector.

It can be observed that if power density f/20000 will be considered for the compliance distance then it can be seen that observed compliance distance is between 14 to 18 m

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Near field behavior of GSM antenna with 4 carriers in one sector

Distance (Meter)

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RADIATION SHIELD

A “Radiation Shield” consisting of multiple orthogonally polarized broadband monopole antennas (800 to 4000 MHz)has been developed.

The antennas are terminated in matched load to absorb the harmful radiation to produce a safe radiation free environment.

It also has a LED which lights up (without battery) when a strong radiation source is brought close to it.

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in the frequency range of 800 MHz by

different LED colors has been decided

Biological Effects of Cell TowerRadiation on Human Body

Now days in most of the places the towers are

constructed over upon the building.

Human body absorbs radiation, because human

body consists of 70% liquid.

More than adults, children's are affected highly.

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Effect on Environment

Effect on Honey Bees

Effect on Birds

Effect on mammals and amphibians

Effect on Plants

Effect on human body

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Case study

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people living in the front side of the antenna will receive

much higher radiation compared to people living in the

back side of antenna.

For a single transmitter, power density at R = 50m is equal

to 0.0318W/m2 = 31,800 μW/m2.

Even for 3 transmitters in the same direction, it comes out

to be approximately 0.1 W/m2 = 100,000 μW/m2

RADIATION NORMS ADOPTED IN

INDIA AND OTHER COUNTRIES

In India, we have adopted radiation norms given by

ICNIRP guidelines

Safe power density is f/200, where frequency (f) is

in MHz

For GSM900 transmitting band (935-960 MHz),

power density is 4.7W/m2

For GSM1800 transmitting band (1810-1880 MHz),

it is 9.2W/m2.

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The Cell Phone providers havinginstalled the towers will be asked toprovide the following technicaldetails for operating parameters ofthe installed towers for scientificevaluation.

a. Peak power/frequency

from each Antenna

b. RF amplifier Model and its

specification

c. Type of Antenna and its

radiation pattern

d. Land clearance requirement

around a tower

GERMANY

a. <0.1 μW/m2 - no concern

b. 0.1 - 10 μW/m2 - slight

concern

c. 10 - 1000 μW/m2 - severe

concern

d. > 1000 μW/m2 - extreme

concern

Health concerns with current Safety Guidelines

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Conclusion

The seriousness of the health hazards due to radiation from

cell towers has not been realized among the common man.

Its effect on health is noted after a long period of exposure.

The compliance distance varies with antenna gain,

transmitting power, frequency.

Stricter radiation norms must be enforced across globe.

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Mobile companies should not be in the denial mode.

The radiation causes serious health problems.

Only then people all over the world will carry out

research to come out with solutions.

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Cont.

Refe

ren

ces

the Peculiar Circumstances of the IARC Working Group on Radio Frequency Electromagnetic Fields and Cellular Telephones IEEE Antennas and Propagation Magazine, Vol. 53, No.3, June 2011.

Evaluation of RF EMF exposure pattern on selected communication towers in Malaysia-2011.

ICNIRP - International Commission on Non-Ionizing Radiation Protection -Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic fields (up to 300 GHz), Health Phys, 1 sep 2012.

Levitt B, Lai H, Biological effects from exposure to electromagnetic radiation emitted by cell tower base stations and other antenna arrays, Environ. Rev. 18: 369–395, 2010 – http://article.pubs.nrccnrc. gc.ca/RPAS/rpv?hm=HInit&journal=er&volume=18&calyLang=eng&afpf=a10-018.pdf

N. Kumar and G. Kumar, Biological Effects of Cell Tower Radiation on Human Body, IEEE Conf. ISMOT, pp.1365-1368, Dec. 2009.

Z. W. Sim, R. Shuttleworth, and B. Grieve Investigation of PCB Microstrippatch receiving antenna for outdoor RF energy harvesting in wireless sensor networks, IEEE Conf. Antenna and Propagation Conference, Loughborough, pp.129-132, Nov. 2009

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