Aug-Oct 14 issue of JES

RESEARCH PAPERS ADVANCED EMBEDDED ELECTROMAGNETIC RADIATION MONITORING SYSTEM By S.VENKATESULU*

S.VARADARAJAN**

M.N.GIRI PRASAD***

A.CHANRDA BABU****

* Research Scholor, Jawaharlal Nehru Technological University, Anantapuram. ** Professor, Sri Venkateswara University, Tirupati, India. *** Professor, Jawaharlal Nehru Technological University, Anantapuram. ****Associate Professor, Yogananda Institute of Technology and Science , Tirupati.

ABSTRACT The design and implementation of Advanced Embedded Electromagnetic Radiation Monitoring System (AEERMS) for the monitoring of the non-ionizing Electromagnetic radiation is presented in this paper. AEERMS monitors the exposure of electromagnetic radiations continuously that are radiated from different RF sources.As per the pressing need, there is a tremendous increase in the usage of cellular mobile communications and broadcasting systems. Which in turn increases the number of cell towers.All the cell towers together, transmit several tens to hundreds of watts of power, and the continuous exposure to this Electromagnetic (EM) radiation results in severe health problems like Brain Tumor, Blood Brain Barrier, Eye& Hearing etc. A systematic and continuous monitoring of the EM radiation is necessary to regulate the radiation level. The proposed system called AEERMS has the provision for continuous monitoring and display of radiation levels in the mobile network based on their frequency range and stores and/or transfers the data to concerned authorities. The proposed AEERMS was successfully implemented in measuring the radiated power of the received signals with frequency ranges from 80 MHz to 2.5 GHz. In addition to, this system is also capable of scanning all possible frequencies in its vicinity and thus measures the total radiated power for all the signal frequencies. The performance of the AEERMS is validated with BSNL drive test, tirupati at GSM frequency of 1800.6 MHz and at 3G frequency of 2156 MHz. The AEERMS is set in use under different traffic conditions, viz., normal and busy traffic conditions, at various distances from the cellular base station. It is observed from the measured radiations, the radiation level in busy hours is larger than that in normal hours, with irrespective of the distance from the cellular base station. The radiation levels are indicated by the particular frequency and radiation in terms of power levels. If the radiation level is above -30 dBm, then the monitoring system indicates it as a dangerous level of radiation, and it sends short messages to the concerned authorities indicating about the dangerous level of radiation of particular frequency in a particular place. The radiation levels are taken from BioInitiative (report) 2007 and 2012. KEYWORDS: Radiated Power, Frequency, Cell Site, Monitoring, Radiation Level. INTRODUCTION

day. In India currently there are nearly 5.5 lakh cell phone

Cellular mobile communication was started to be widely

towers, and to meet the communication demand; the

utilized in the 21 century all over the world [7], [6], [18].

number will increase to 10 lakh towers by

From the beginning, utilization of them has rapidly risen.

2020[5],[11],[3],[4],[9]. The majority of these towers was

Because of the augmenting number of mobile phone

mounted near the residential and office buildings to

users, the numbers of base stations, which enable mobile

provide good mobile phone coverage to the users. The

phones to connect to other mobile phones, are to be

base station tower and its transmitting power are

increased to provide a better communication. Therefore,

designed in such a way that it covers a distance at which

base stations are to be mounted closer to each other.

the received signal strength is enough for proper

With an increase in cellular mobile communication, number of cell towers getting installed is increasing every

communication. A building located near to the cell tower receive more strong signals than the building located

i-manager’s Journal on Embedded Systems, Vol. 3 l No. 3 l August - October 2014

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RESEARCH PAPERS farther from the cell tower. Continuously receiving of these

the different RF sources. It consists of printed elliptical

harmful signals causes serious health hazards to the

planar monopole patch antenna, [14], [17], ARM

people [8], [10]. In cities urban and suburban areas like

controller, [16] and [12] Module. All these compoments

Chennai, Hyderabad, Vizag, tirupathi, Bangalore, Delhi,

are integrated into a single system block diagram

etc., millions of people reside within these high radiation

representation is shows in the Figure 1.

zones.

The printed elliptical planar monopole patch antenna

The electromagnetic environment consists of natural

receives signals of frequencies ranging from 80 MHz to 2.8

radiation and man-made electromagnetic fields that are

GHz. Initially, the antenna is virtually simulated in the

produced either intentionally or as by-products due to the

Computer Simulation Technology (CST) studio and

use of electrical devices and systems. The natural

analysis of the antenna performance is carried out by

electromagnetic environment originates from terrestrial

computing the parameters like return loss, VSWR,

and extraterrestrial sources such as electrical discharges

impedance, radiation pattern etc. When satisfied with the

in the earth's atmosphere and radiation from the sun and

simulation results, the antenna is practically fabricated on

space. The everyday use of devices and systems emitting

a square shaped substrate RT Rogers (5880) material. The

radio frequency (RF) electromagnetic fields is increasing

fabricated antenna with VSWR < 1.3 is capable of

continuously. Sources generating high levels of

receiving the signals in the frequency range of 1700 MHz

electromagnetic fields are typically found in medical

and 2.4 GHz. The parameters of the fabricated antenna

applications and at certain workplaces. Medical devices

are practically verified at DLRL, Hyderabad [19].

used for magnetic resonance imaging, diathermy,

2. Experimental Setup

hyperthermia, various kinds of RF ablation, surgery, and diagnoses may cause high levels of electromagnetic fields at the patient's position or locally inside the patient's body [13], [2], [15]. For broadcasting, high RF power is generally required to maximize the area of coverage. Close to the antennas, electric field strengths can reach several hundred volts per meter. Even higher values can be found close to occupational sources used for processing of various materials by heating and sometimes by formation of plasma discharge in the material. In many such applications, RF-safety problems

The experimental setup consist of fabricated antenna (Printed Elliptical Planar Monopole Patch Antenna), RF2052 manufactured by RF micro devices, Si4362 designed by Silicon Labs, NXP semiconductors manufactured ARM 32-bit (LPC2148) Controller [1], CP2102 data transfer module designed by silicon labs [16], [17], [12], [RMD] a general purpose Persona Computer (PC) is used as display section, and a GSM module as a data dongle. The general purpose PC loaded with visual Basic 2010 and CDEEC-RF PC Client (visual basic 2010) is used for both the graphical

arise because RF- power is high and it may be difficult to enclose the field-generating electrodes and processing space inside a good electromagnetic shield. Sources used by the general public for example, wireless communication, data transmission or food processing generates comparably much lower fields at the position of the user. But this may also depend on the behavior of the user, especially concerning the distance to the source. 1. Implementation of Advanced Embedded Electromagnetic Radiation Monitoring System The proposed system is used to monitor EM radiation of 2

Figure 1. Block Diagram of Advanced Embedded Electromagnetic Radiation Monitoring System


RESEARCH PAPERS interpretation of the data and the interfacing between the

signal is evaluated using ARM controller. The strength of

user and the monitoring system.

the signal that is evaluated in Si 4362 can be viewed in the

The signal received by the antenna is fed to [14] which has

display section of the PC side. This is the radiated power in

a wideband RF PLL/VCO with integrated RF mixer. Then the

the corresponding frequency range from the particular

signal is brought to [17] which is having RSSI (Received

antenna.

Signal Strength Indicator) which estimates the signal

If the radiation level exceeds the desired limit, the a short

strength in the channel to which the receiver is tuned. The

message will be sent to the corresponding authorities

signal is then given to ARM controller via CP 2102 which is a

using GSM module indicating about the dangerous level

highly-integrated USB – to – UARTBridge Controller that

of radiation from the cell site. So that it helps them to take

provides a simple solution for updating RS-232 designs to

necessary remedies to decrease the radiation from that

USB. The USB is connected to a personal computer in

particular cell site.

which the data transfer takes place serially. ARM

3. Results and Discussions

Microcontroller is linked to a PC through RS-232 port. The PC displays the menu for selecting required frequencies. After selecting the corresponding frequency the PC displays its radiated power at the particular place and the total radiated power in the entire band. Using GSM Module for alerting authorities in case of electromagnetic radiation exceeds the actual limit through SMS.

AEERMS is used in a variety of measurement campaigns. Initial Measurements for data verification and usage analysis were performed on cellular base station towers and also others sources of RF. A majority of cellular base stations exhibit near 100% power radiating during their busy operational hours. As part of AEERMS is monitoring 24x7 for all hours and also if the radiation is found to

The experimental setup of the AEERMS is shows in Figure 2.

exceed the safety limits prescribed by the FCC, then it will

This experimental setup shows the embedded version of

send a message about exceeding the safety limits of

the different components of the advanced embedded

radiation to concerned authority officers.

electromagnetic radiation monitoring system.

Radiation measurements were carried out at various

The functing of AEERMS is as follows: Initially, the required

places in Tirupathi, Renigunta and Madanapalli. Some of

frequency is selected by using the display section of the

these readings are shown figure below. It may be noted

PC loaded with CDEEC RF PC Client (Visual Basic 2010)

that on Tirupathi-Renigunta near Reliance mart on Bridge,

software. The information about this frequency is sent to RF

the measured radiated power was as high as -26 dBm,

2052 through the ARM controller. The RF 2052 then tunes its

which is equivalent to 70,686μW/m2 as there are 4 cell

receiver to that frequency, so that it can be able to

towers near on reliance mart and near 100 meters

receive only those signals from the antenna in the range

distance Figure 3 shows the radiation measured using

of centre frequency. The signals that are received by the

AEERMS, in the residential buildings within the distance of

RF 2052 is then given to Si 4362 where the strength of the

150 metre from the cellular base station operating at GSM frequency of 1800 MHz (with Centre frequency 1850 MHz

Figure 2. Experimental setup of AEERMS

Figure 3. Radiated Power at GSM 1800MHz (busy traffic)


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RESEARCH PAPERS and frequency span 300 MHz requested by the user).

Using AEERMS, the radiation is measured in the close

From this figure, it is clear that the radiation level reaches a

proximity (about 50 metre) of the cellular base station

maximum of -38.5 dBm at the frequency 1874.107 MHZ.

operating at GSM 1800 MHz frequency, and the received

Using the AEERMS, the radiation measured at the place

radiation is shows in Figure 6. From this figure, it is evident

which is about 150 metre distance from the cellular base

that the radiation level in the 50 metre radius is very larger

station, operating with 3G frequency 2100 MHz (with

(0dBm = 1 mW) than the safety limit -30 dBm (= 1 µW).

Centre frequency 2250 MHz and frequency span 500

The AEERMS is used to observe the electromagnetic signal

MHz) is graphically represented in the Figure 4. It is clear

strength during normal traffic conditions.

from this figure that, the maximum radiation level is -44

Figure 7 shows the measured radiation power during the

dBm at the frequency of 2165.179 MHZ.

normal traffic hours, at a distance of 150 m from the

The AEERMS is capable of scanning all the available

cellular base station operating at 3G frequency of 2100

frequencies in its vicinity by selecting the all-mobile bands

MHz. It can be observed that, the power level observed in

provided in the display module. Figure 5 shows the

the normal traffic conditions is reduced by 10 – 100 times

radiation level measured using this system in the 'all

that of the busy traffic condition.

mobile bands' mode. It is clear from this figure, that the

The radiation power levels from a cellular base station

maximum radiation level -28.5 dBm exceeds the safety

observed during the normal traffic conditions at a

radiation limit -30 dBm at the frequency 2290.179 MHz. It

distance of 150 m shows in the Figure 8. From this figure, it

means that the place is affected with danger level of

is clear that, the received power during the busy traffic

electromagnetic radiation at this particular frequency.

hours, is very larger than that of the normal traffic hours.

Also, the total radiated power detected by the AEERMS is

Figure 9 shows the measured total radiation power during

1.0268 µW which is hazardous level of electromagnetic radiation power in that location.

Figure 6. Radiated Power at GSM frequency 1800MHz (busy traffic)

Figure 4. Radiated Power at 3G frequency 2100 MHz (busy traffic)

Figure 5. Radiated Power in the entire frequency band with an indication of danger level of radiation (busy traffic)

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Figure 7. Radiated Power at 3G frequency of 2100 MHz (normal traffic)


RESEARCH PAPERS the normal traffic hours, at a distance of 150 m from the

signal from the mobile unit, which is connected to PC

cellular base station. It can be observed that, the total

loaded with ACTIX Analyzer software. This software

radiated power level observed in the normal traffic

facilitates in graphical display of received power, call

conditions is reduced by 10 – 100 times that of the busy

failures and call drops etc. of that particular network in that

traffic condition.

particular location. BSNL drive test can be operated in the

The AEERMS continuously compares the signal strength

frequency range of 800 MHz and 2.5 GHz.

received from the IC Si4362 with the safety, radiation limits

The Figure 11 shows a snap shot taken while comparing

prescribed by the FCC, and if the received radiation

the measurements of the AEERMS with that of BSNL drive

power is more than the safety limits, it will activate the GSM

test.

module to send a message to the concerned authorities

A comparison is made between the results obtained using

about the danger level of radiation at a particular

the AEERMS and the BSNL drive test performed at the

frequency and place. Some sample snap shots of

frequencies 1800.6 MHz and 2156 MHz and are

messages are shows in the Figures 10.

graphically represented in the Figures 12 and 13. From

4. Comparison With BSNL Drive Test

these figures, one can observe that the measurements

The performance of the advanced embedded

obtained using the AEERMS agree with those obtained by

electromagnetic radiation monitoring system is

using the BSNL drive test.

evaluated by comparing its measurements with the

It is observed from the graphical representations of the

known existing system for radiation monitoring. Here, the

results that the radiated power received in both the cases

BSNL drive test is considered as the known existing system

is almost equal. Moreover, BSNL drive test is capable of

for electromagnetic radiation monitoring system to

detecting its operating frequency only, where as the

validate the measurements obtained by the AEERMS.

proposed system is able to receive the radiation power in

In the BSNL drive test, the system receives its own network

Figure 8. Radiated Power at GSM frequency 1800 MHz (normal traffic)

Figure 10. The alert message indicating harmful radiation at some place in Tirupati

Figure 9. Total Radiated Power (normal traffic)


Figure 11. A snap shot while measuring the radiation using BSNL drive test

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RESEARCH PAPERS the wide band of frequencies 30 MHz – 2.5 GHz. The

observed that the system is able to detect the radiation

fabricated antenna (Printed Elliptical Planar Monopole

corresponding to a particular frequency. Moreover, the

Patch Antenna) is capable of receiving the signals in the

AEERMS scans all the possible frequencies in its vicinity and

frequency range of1700MHz–2.5GHz.

thus measures the total radiated power corresponding to

Conclusion

all the frequencies in the band 80 MHz – 2.5 GHz.

The design and implementation of a system to monitor

The performance of AEERMS is validated with BSNL drive

the electromagnetic radiation is emphasized more in this

test. The BSNL drive test has been carried out for one hour

thesis work. The proposed electromagnetic radiation

with GSM frequency 1800.6 MHz and one hour with 3G

monitoring system is called advanced embedded

frequency 2156 MHz. From the BSNL test drive, it is

electromagnetic radiation monitoring system.

observed that the designed system can sense the

Advanced embedded electromagnetic radiation monitoring system is designed to monitor the real time electromagnetic radiations produced by cellular base stations, mobile units, and the other RF sources. The designed system (AEERMS) is subjected to testing at different places, at different times (normal, busy), and it is

radiation power level as equal as that of BSNL drive test. Moreover, the BSNL drive test is limited to detect its operator frequency only, whereas, the proposed device can detect the radiation of the different cellular networks. The AEERMS has the provision to send SMS to the Telecom authorities about the radiation level of the particular frequency at the particular place. Other electromagnetic radiation monitoring systems, except AEERMS have neither the details of the radiation corresponding to a particular frequency nor the SMS provision to inform the concern authorities about the radiation level. Following recommendations are made to reduce the effect of electromagnetic radiation. 1. The cellular base stations should be installed in such a way that, the minimum distance between individual base stations should be around 5 km.

Figure 12. Comparison of results obtained by using the Proposed system (AEERMS) and the BSNL drive test at the frequency 1800.6 MHz

2. The height of the cell tower antenna should be more than 50 m, if the base station is installed in the residential areas. 3. The Effective Radiated Power (ERP) of the cellular base station should be made as minimum as possible, to avoid the hazardous level of radiation. Acknowledgement This work has been supported by BSNL, Tirupathi. References [1]. ARM LPC2141/42/44/46/48, Rev. 5-12 August 2011 Product data sheet, 2011, 1-456. [2]. Ashok Kumar et al ( 2013). Designing of an Equipment

Figure 13. Comparison of results obtained by using the proposed system(AEERMS) and the BSNL drive test at the frequency 2156 MHz

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for Monitoring Electromagnetic Radiation IJMCTR, Vol.1 No.8, pp.21-30.


RESEARCH PAPERS [3]. Bio-initiative Report (2012). A Rationale for a

[11]. Mobile Telecommunications and health research

Biologically-based Public Exposure Standard for

programme (MTHR) Report 2007. 1-345.

Electromagnetic Fields (ELF and RF) pp. 1451-1457.

[12]. PSI-GPRS/GSM-MODEM/RS232-QB, 2012, 1-48.

[4]. Girish Kumar. (2010) Report On Cell Tower Radiation

[13]. Ray,K.P. Hindawi. (2008). Publishing Corporation

Submitted To Secretary, DOT, Delhi.2010,1-50.

International Journal of Antennas and propagation,

[5]. Installation and configuration: Horizon II macro cell

Vol11,No.6, pp.1-8.

report. 1-215.

[14]. RF Micro Devices, RF2052 Data sheet, 2012,1-58.

[6]. Report of the Inter-Ministerial Committee on EMF

[15].Sabah HawarSaeid. ( 2003). Proceedings of the 2013

Ra d i a t i o n, G o v e r n m e n t o f I n d i a, M i n i s t r y o f

International Conference on Electronics and

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of Telecommunications,2010. 1-50. [7]. P.D. Inskip, R. Tarone. ( 2001). “Cellular-Telephone Use And Brain Tumors”, The New England Journal Of Medicine, Vol. 344, No. 2, pp.79-86 [8]. Mallalieu Kim. (2010). “Report on BVI Radiation Measurement Project”, Communication Systems Group, Department of Electrical and Computer Engineering, The University of the West Indies , 1-355. [9]. Kumar, N and Kumar, G. ( 2009). “Biological effects of cell tower radiation on human body”, ISMOT, Delhi, India, pp. 678-679. [10]. Liu,W.C. and Hsu C.F, IEE Electronics Letters, Vol.4

[16]. Silicon Laboratories CP2102/9, 2012, 1-36. [17]. Silicon Laboratories Si4362, 2012, 1-46. [18]. Mobile communication radio waves & safety, Department of the telecommunications ministry of communication & IT, Government of India, 2010. pp.135. [19]. Venkatesulu S, Dr. Varadarajan S and Dr. Giri Prasad, M. N and Dr. Thenappan, S. (2013). “Printed Elliptical Planar Monopole Patch Antenna for wireless communications” 2013 International Conference on Green Computing, Communication and Conservation of Energy (ICGCE). IEEE Xplore Digital Library pp. 314-319.

No.132005390-391.


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RESEARCH PAPERS ABOUT THE AUTHORS S.Venkatesulu is currently pursuing his PhD and working as Associate Professor, Yogananda Institute of Technology and Science, Tirupati. He received Master of Technology in Embedded System and Bachelor of Technology degree in Electronics and Communication Engineering from JNTUH. His research areas include Embedded Systems, Antenna Design, and Electromagnetic Radiation Analysis.

S. Varadarajan currently working as Professor in the Department of Electronics and Communication Engineering, Sri Venkateswara University College of Engineering, Tirupati. He receivedh is B.Tech degree from Sri Venkateswara University, Tirupati, M.Tech degree from Regional Engineering College Warangal, Andhra Pradesh, and Ph.D from Sri Venkateswara University Tirupati, Andhra Pradesh, India. His research areas are signal and Image Processing, Digital Communications. He is member IETE, ISTE & IEEE. He is the chairman of IETE Tirupati centre.

M. N. Giri Prasad, is Currently working as Professor and Head of the Electronics & Communication Engineering Department, at Jawaharlal Nehru Technological University, Anantapur. He received his B. Tech degree from JNTU Anantapur, M. Tech degree from Sri Venkateswara University, Tirupati and Ph. D degree from Jawaharlal Nehru Technological University, Anantapur. His areas of interest include Wireless Communications, Signal and Image Processing, and Biomedical Instrumentation. He is a member of ISTE and IE & NAFEN.

A. Chandrababu is currently working as an Associate Professor in the Department of Electronics & Communication Engineering Department at Yogananda Institute of Technology & Science. He received his B. Tech degree from Jawaharlal Nehru Technological University, Anantapur and M. Tech degree from National Institute of Technology, Rourkela. His areas of interest include Communication Systems, Embedded Systems and DSP Processors.

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