 Open Access
 Total Downloads : 350
 Authors : S. Malathi, G. Tirumalarao, G. Rajeswer Rao
 Paper ID : IJERTV2IS120045
 Volume & Issue : Volume 02, Issue 12 (December 2013)
 Published (First Online): 05122013
 ISSN (Online) : 22780181
 Publisher Name : IJERT
 License: This work is licensed under a Creative Commons Attribution 4.0 International License
A Prediction Model for Electromagnetic Pollutin Index of Multi System Base StationsA Prediction Model for Electromagnetic Pollutin Index of Multi System Base Stations
1S. Malathi, 2G. TirumalaRao, 3G. Rajeswer Rao 1,2,3 Dept. Of E. C. E, G. V. P College of Engineering (A), Madhurawada, Visakhapatnam 530048, India.
Abstract: mobile telephone is among the most popular consumer electronic devices in the modern world today. This has resulted in rapid increasing in number of mobile base stations to ensure good coverage and better quality of services, thus causing anxiety among the members of the public regarding the potential health effects caused by the radiation produced the base stations. It gives rise to a compelling case to reduce the electromagnetic pollution (EMP).
So an objective measure is a prerequisite to model, measure, monitor and manage EMP. In this paper, EMP definitions and modeling have been deal with elaborately for mobile communications and proposed electromagnetic pollution index (EPI) for multiple base stations. Relationships are derived to check the influencing factors effect on environment and to give guidelines for consideration of EPI. To illustrate the use of EPI an example is presented. And Simulations are performed by using MATLAB tool.
Keywords: EPI(Electromagnetic pollution index), EMR(electromagnetic radiation), multisystem base stations, electromagnetic pollution.
INTRODUCTION
Where
Si = Received power density from the i th emitter
(,) = Effective aperture area for the direction of arrival (,)
The polluting energy may be expressed as integral of power i.e
E(X,Y,Z) = Si(t) (,) dt
for all Si > . (2)
In the case of mobile communications, it is not practical to evaluate or measure the energy at all the points or even representative points to objectively measure or compare EMP. Based on the threshold concept, it is postulated that EMP is limited to a few areas where the Base Transmitting Stations (BTS) and mobiles are radiating within a cell. Such areas may be termed as Pockets of Pollution (POP).

Definition of Electromagnetic Pollution Index (EPI)
1 Definition of EMP in mobile communication
The EMR is considered to be harmful if the power density from multiple sources exceeds a threshold level [9]. The power from multiple sources is, in general, additive and may be expressed at a point(x,y,z) as
P(X,Y,Z)= Si (,)
for all Si > . (1)
The Electromagnetic Pollution Index (EPI) is defined as a product of the normalized polluted area and polluting energy. The normalized polluted area is the ratio of sum of areas of all packets of pollution (POP) and area of cell, and the polluting energy is the sum of energy in all POP. It can be expressed as
EPI = Sum of area of all POP
Area of cell
( sum of energy in all POP) . (3)
EPI equation can be established in simple form under considerations free space propagation, no power control and isotropic antennas for the transmission of radio frequency signal.
Assuming (,)=1,
EPI = 1 ai T Pi t dt . (4)
() = horizontal plane directional values for ith base station
() = vertical plane directional value for ith base station
N= number of base stations
Let us assume shaped gain= = 1db then
A 0 electromagnetic radiation power will be S= P that
Where
means according to single base station and = ;
EPI = EMP Index in WattHours
= Then from above equation4
= ()2 ()2 100 . (6)
A = Area of the cell
ai = Area of ith POP
4
But from the simple antenna received power equation
Pi = power measured by omni directional
P = Pt Gt
4
. (7)
antenna at a distance of 1m on the boresight of transmitting antenna
Assuming no power control, the minimum signal required at the maximum distance is given by
T = Time period (suggested as 24 hours)
Pmin =
Pt Gt Gr Rmax
2
2
2
. (8)
4
2
2

Simplified model for EPI for multiple base stations:
In this section, a simplified model of EPI is
Assuming isotropic antenna and substituting for Pt in above equation(7) yields
P = P
R2 4
. (9)
presented. Considering the antenna characteristic parameters, such as the normalized directivity function, antenna gain, gain of the array element,
min
max
2
shaped gain and so on. And the distribution of its power density of the multi system base station S is:
Substituting in (4), EPI is given by
aj T
EPI = P
d(t) . (10)
R2 4
R2 4
2 2
A 0 min
max 2
=
=1
42
() () 100
. (5)
The above equation represents the summation of all the mobile emitters in a cell, but we
Where
S= electromagnetic radiation due to multiple base stations
=array of transmitting antenna power due to ith bas staton
required the summation of overall emitters i.e. BTS as well as all mobiles in single POP. So by separating the BTS related and mobile related terms in equation
(10) gives modified EPI as
EPI = 1 a
+ a P
P2 4
uv +
1
1
= Array gain and shaped gain due to
A BTS
j min
max
2 1 i
ith base station
M Tj . (11)
From above equation is considered = Area of Nth base station
P =
2 4 2 ()2
100
u = Number of channels per Trans Receiver(TRX)
2
. (12)
v = Number of TRX
According to definition of EPI, the equation for multiple base stations is derived as
= Average transmit time for ith channel of BTS
EPI =
EPI =
=1
=
=
=1
=
0
+
= Average transmit time for jth mobile M = Number of nodes
= Duty ratio of time slot
=1
= handoff power between different base
1 1
1 1
+
. (13)
At the time of handover between two cells, same amount of extra power we require to proper handoff. So EPI is given as
station cells

Data Analysis
S.NO 
DISTANCE (m) 
POWER DENSITY (ÂµW/m2) 
EPI (WattHr) 
1 
5 
443.0569 
5.3394 e+008 
2 
10 
110.7642 
3.0471 e+008 
3 
15 
49.2285 
1.9576 e+008 
4 
20 
27.6911 
1.4083 e+008 
5 
25 
17.7223 
1.1848 e+008 
6 
30 
12.30 
9.5145 e+007 
7 
35 
9.0420 
8.94 12e+007 
8 
40 
6.9228 
6.8456 e+007 
9 
45 
5.4698 
6.3767 e+007 
10 
<>50 
4.4306 
5.8230 e+007 
11 
100 
1.1076 
2.7877 e+007 
S.NO 
DISTANCE (m) 
POWER DENSITY (ÂµW/m2) 
EPI (WattHr) 
1 
5 
443.0569 
5.3394 e+008 
2 
10 
110.7642 
3.0471 e+008 
3 
15 
49.2285 
1.9576 e+008 
4 
20 
27.6911 
1.4083 e+008 
5 
25 
17.7223 
1.1848 e+008 
6 
30 
12.30 
9.5145 e+007 
7 
35 
9.0420 
8.94 12e+007 
8 
40 
6.9228 
6.8456 e+007 
9 
45 
5.4698 
6.3767 e+007 
10 
50 
4.4306 
5.8230 e+007 
11 
100 
1.1076 
2.7877 e+007 
Field measurement approach was chosen to analyze cell tower radiations in various regions. From power density measurements and some of the assumptions EPI is predicted, shown in table..
EPI =
+ +
=1
1
1
1
+ . (14)
And substituting P value from equation obtained the EPI for multiple base stations
EPI = +
2
=1
4 2 ()2
100
2
+
+
. (15)
Where
1
1
Table 1 Density and EPI prediction values for multiple base stations:
= Area of POP due to Base station N
= Area of POP due to jth mobile in Base station N
The table 1.1 gives information that at the center of the base station the maximum radiation or power density occurs and where the mobile unit
moves away from the base station the Electromagnetic radiation decreases. Accordingly the electromagnetic pollution index value varies with respect to distance.
6. Illustration
It can be illustrated with an example of considering single base station having radius R=3000 m as shown in figure (a). the same geographical area is covered by splitting into 7 cells, each of radius r=1000m , as shown in figure(b).
The values of number of channel per trans receiver and number of trans receivers are taken as u=8 and v=7 respectively for larger cell and v=1 in smaller cell. Then the surface plots of radiated power in micro watts per m2 in POP due to BTS for threshold =170 ÂµW/m2 for large cell and small cell is shown in figure1.1 and figure1.2
.
Figure (a) & (b)
Figure.1.1: Pocket o Pollution for Radius of 3000m
\
Figure1.2 : Pocket of Pollution of Radius of 1000m
It is critical to manage EMP to accomplish True Green Mobile Communications. Defining an objective measure for EMP is a necessary first step. In this thesis, EPI for multiple base stations is proposed as the product of normalized area of POPs and polluting energy. Such an objective measure is expected to help in quantifying EMP, comparing alternative network designs and managing EMP. A simplified model for EPI for multiple base stations has been presented, along with an illustrative example. This model is compared with practical measurement model by using Android Mobile with an application of RF Signal Tracker.
This model is helpful in gaining insights into this new field, leading to the identification of several multidisciplinary research areas for further work. The simplified model validates the intuitive strategy to use smaller cells to reduce EMP. As smaller cell size also facilitates other green practices, the future points to Pico and Nanocells as the way for a greener and safer biosphere.
REFERENCES

Telecom Regulatory Authority of India, Consultation Paper on Green Telecommunications, pp. 3, February 2011.

Adamantia Fragopoulou,1 Yuri Grigoriev,2 Olle Johansson,3 Lukas H Margaritis,1 Lloyd Morgan,4 Elihu Richter5 and Cindy Sage6 Scientific panel on electromagnetic field health risks: Consensus points, Recommendations, and Rationales scientific meeting: Seletun, Norway, November 17 21, 2009 reviews on Environmental health volume 25, no. 4, 2010.

Guidelines for limiting exposure to time varying electric, magnetic and electromagnetic fields (Up to 300GHz), Health Physics, International Commission on NonIonizing Radiation Protection, Vol. 74 No 4, 1998.

WHO press release, IARC classifies radio frequency electromagnetic fields as possibly carcinogenic to humans, No. 208, May 2011.

Committee on the Environment, Agriculture and Local and Regional Affairs, The potential dangers of electromagnetic fields and their effect on the environment, Doc. 12608, May 2011.

Ulrich Warnke, Bees, Birds and Mankind Destroying Nature by Electropollution; A Brochure Series by the Competence Initiative for the Protection of Humanity, Environment and Democracy.

Ministry of Environment and Forests, Government of India report, Possible impacts of communication towers on wildlife including birds and bees, October 2011.

O. GenÂ»c, M. Bayrak, and E. YaldÂ³z Analysis Of The Effects Of Gsm Bands To
The Electromagnetic Pollution In The Rf Spectrum Progress In Electromagnetics Research, PIER 101, 17{32, 2010

AF Ismail, W.Hashim Predicting Radio Frequency Radiation From mobile communication Base stations International Journal of Computer and Communication Engineering,Vol.2,No.4, July 2013.

P. Venkatapathy, J. Jena, A. Jandhyala, Electromagnetic Pollution Index
A Key Attribute of Green Mobile Communications, IEEE, 2012.