Sa college emi compliance approaches and techniques in the deployment of mobile communication antennas211120

EMI Compliance
Approaches and Techniques in the deployment of
Mobile Communication Antennas
J.Santhanakrishnan
Formerly Deputy General Manager
BSNL
Chennai.
email:bsnljsk@gmail.com
Mobile:9444001323

Outline
 Background/Introduction
 Electromagnetic Radiation
 Non Ionising Radiation
 Mobile Architecture
 Radiation and human health
 Regulatory Aspects.
 Safety Limits
 Self declaration by operators
 Implementation of safety by Govt body

Basic principles of EMF
energy
5/1/2021 4
Alternating electric current flows through the solenoid on the left,
producing a changing magnetic field. This field causes, by
electromagnetic induction, an electric current to flow in the wire
loop on the right.

EMF
 Electric, magnetic and electromagnetic
fields exist wherever voltages and
currents are present.
 Broadcasting facilities for radio,
television and telecommunications emit
electromagnetic fields, as do industrial
facilities and medical equipment

EMF
 When it comes to fields which influence the
environment and particularly humans, we
tend to use the terms “environmental
electromagnetic compatibility”(EMC)
and“electromagnetic fields” (EMF).

EMF & EMC
 Relates to the electromagnetic
compatibility of equipment.
 EMC guidelines say how much
spurious radiation equipment is
allowed to emit and what amount of
electromagnetic radiation it needs to
withstand.
 The CE mark is a guarantee of
compliance with these guidelines.

Radiation
 Radiation is a form of energy on the
move.
 Radiation is electromagnetic in
nature,
 i.e., it consists of waves of electric
and magnetic energy moving
together through space at the speed
of light.
 We live in a radiation world and are
exposed to both natural and man-
made radiation.

Radio Frequency
 Alternating fields are divided into
• Low-frequency fields (up to about
100 kHz)
• RF & microwave fields (from100 kHz
up to 300 GHz).

Sources of Electro-magnetic Energy
Radiofrequency (RF) Electromagnetic Energy
 3 kHz to 300 GHz (0.003 to 300,000 MHz)
 “microwaves” are radiofrequencies above 300 MHz
Natural Artificial
Sun Light
Home Industrial Community
Micro oven Dielectric Heaters Commercial Radio
Cordless Phone
Medical
Diathermy Television
Mobile Phone Microwaves Telecommunications
Induction Heaters

EMF Radiation from Mobile Antenna

Spectrum in Mobile Communication
 1st generation (1G)
• Analog phones; early 80’s; 450 & 900 MHz
 2nd generation (2G)
• Digital (Global System for Mobile
Communication, or GSM); early 90’s; 900 &
1800 Mhz
 3rd generation (3G)
• Universal Mobile Telecommunication System
(UMTS); 2003; 1800-2200 MHz
 4th generation (4G)
• Still relatively new; frequency 2000-8000 MHz
5th generation (5G)
• 30GHz

Increasing EMF?
 Each successive generation has
operated at a higher frequency:
more apps = more power
 Usage increasing…and fast!
 The teledensity (urban) in India as
on March 2012 --- 78.66%
 2019----161.34%

What Does Science Tell Us?
•RF-EMR is similar in energy to
AM/FM radio waves, microwaves,
and infrared heat lamps
•non-ionizing radiation
•not capable of breaking
molecular bonds (e.g., DNA)
•does not enter body tissues
•same type of radiation used
in MRI technology

Some Basic Definitions
 RF-EMR (RF) – Radio frequency electromagnetic
radiation
 SAR – Specific absorption rate; how much RF
is absorbed into the body when exposed to a
radiation source, such as a mobile device
(measured in W/kg; ≤1.6 in US; ≤2.0 in EU)
 ICNIRP stands for the “International Commission
on Non-Ionizing Radiation Protection”.

Biological Effect of
RF Electromagnetic Energy
5/1/2021 22

Biological Effect of RF
Electromagnetic Energy
Recognised Health Effects due to thermal effect
Heating Effect
Effect on Cataracts
Ankle Currents
RF Shocks and Burns

Range of influence of fields
Field strength decreases rapidly the
further we are from the field source.
This means that maintaining proper
distance from a source is a simple way
to provide protection.

INCREASED DISTANCE FROM RADIATING
SURFACE OF ANTENNA REDUCES EMF EXPOSURE
OF PERSONNEL
EMF Environment
Increasing
distance
from antenna
Increasing
EMF levels

Properties of near and far fields
In the near field, the ratio of the electric
and magnetic fields is not constant
In the immediate vicinity of the
antenna, there are regions where the
electric or magnetic field predominates
almost exclusively.

At increasing distances, however, the ratio
of the electric and magnetic radiation tends
more and more towards a constant value.
This means in the far field it is no longer
necessary to measure the E and H fields
separately in case of electromagnetic
radiation
Properties of near and far fields

The effects of electromagnetic fields
• Frequency
• Field strength
• Field type (E or H field),
• Duration of exposure
• Extent of exposure
(part of body or entire body)
• Signal shape

Regulatory Aspects
5/1/2021 30

What is ICNIRP?
International
Commission on
Non
Ionizing
Radiation
Protection.
It is a body of independent scientific
experts.

Where do limits for EMF come from?
Research evaluates the biological effects.
Scientific Committees such as ICNIRP evaluate
potential risk
Basic limits are agreed upon
National and International limits are derived

1. When it comes to how electromagnetic
fields affect humans, we must use
different values other than those are
used for EMC.
2. Limits for human exposure are stipulated
in the relevant EMF recommendations,
standards and regulations.
3. These values are important in
occupational safety and for protection of
the general public.
Regulations

ITU Recomendations
34
•ITU-T Recommendation K.52 (2004),
Guidance on complying with limits for
human exposure to electromagnetic
fields.
•ITU-T Recommendation K.61 (2003),
Guidance to measurement and numerical
prediction of electromagnetic fields for
compliance with human exposure limits
for telecommunication installations.

EMF Exposure Limits
5/1/2021 35

EMF Exposure Zones
Compliance zone
potential exposure to EMF is below the applicable
limits for both
Occupational zone
potential exposure to EMF is below the applicable
limits for controlled/occupational exposure but
exceeds the applicable limits for
uncontrolled/general public exposure.
Exceedance zone
potential exposure to EMF exceeds the applicable
limits for both 40

Occupational & Compliance Zone

EMF Exposure Limits
ICNIRP
Note1: f is indicated in the frequency range column ; Note2: For frequencies between 100 KHz & 10 GHz, the averaging
time is 6 minutes
Note3: For frequencies exceeding 10 GHz, the averaging time is 68/f1.05 minutes (f in GHz)
(f=frequency in MHz)

EMF Exposure Limits
Indian standard
Indian standards are now 10 times
more stringent than many countries (like USA, Canada, Japan and
Australia) in the world which follow ICNIRP guidelines.

 Limiting reference levels of
Electromagnetic Radiation from Mobile
towers is reduced to 1/10th of the limit
prescribed by the ICNIRP with effect from
01.09.2012.

SAR level for Mobile Handsets
 Adoption of Specific Absorption Rate (SAR) limit
of 1.6watt/Kg (averaged over 1 gm of tissue)
also implemented from 01.09.2012.

 the worst emission conditions;
 the simultaneous presence of several
EMF sources, even at different
frequencies.
47
Exposure level assessment

To be conservative, EMF hazard analyses assume:
 max power into antenna
 antenna transmitting continuously
Service Type Total Power
into antenna
Antenna up-
time
TDMA, CDMA, GSM (digital
wireless)
40 watts Continuous or
intermittent
Microwave Antenna 125 – 500 mili
watts
continuous
EMF Environment –
Working at Ground Level Around
Antenna Support Structures

Parameters to be considered
 the maximum EIRP of the antenna system
Equivalent Isotropic Radiated Power (EIRP));
 the antenna gain G
 the frequency of operation;
 various characteristics of the installation,
such as the antenna location, antenna
height, beam direction, beam tilt and the
assessment of the probability that person
could be exposed to the EMF.
49
Equivalent Isotropically Radiated Power (EIRP): The EIRP is the product of
the power supplied to the antenna and the maximum antenna gain relative to an isotropic
antenna.

Classifications for protection
 Inherently compliant:
Inherently safe sources produce fields
that comply with relevant exposure
limits a few centimetres away from the
source. Particular precautions are not
necessary.
50

Classifications for protection
Normally compliant:
Normally compliant installations contain
sources that produce EMF that can exceed
relevant exposure limits.
However, as a result of normal installation
practices and the typical use of these
sources for communication purposes, the
exceedance zone of these sources is not
accessible to people under ordinary
conditions
51

Classification for protection
 Provisionally compliant:
These installations require special
measures to achieve compliance.
52

Estimation of Total EIRP (EIRP [T])
for each Operator
EIRP (BCCH) = Tx Power – Combiner Loss – (Cable
Length x Unit Loss) + Antenna Gain (dBm)
The EIRP [T] is then given by:
EIRP [T] =EIRP (BCCH) watts +EIRP (BCCH) watts x 0.9
x 0.9 x (Carriers / Sector – 1)

Methods for EMF evaluation
1.Calculation Method( EIRP/EIRP th)
 Site Can be certified as normally compliant if the
value(EIRP/EIRP th) found to be less than one at all points
outside the exclusion area.

2.Electromagnetic Mapping by software simulation
3. Broadband measurement
 This method required if power density exceeding 50 % of
ICNIRP level.
 Site can be certified as normally compliant if measured value
is within the 1% of ICNIRP reference level.
4. Frequency selective measurement
 This method required if broadband measurement value
exceeds 1% of ICNIRP level

Accessibility categories
Accessibility category 1
h

Access. Cat. 4 a
Access. Cat. 4 b

Other Conditions
 If there is any site within 20 m we
have to assume them to be sharing
site and calculate for combined
compliance using formula

The Radio Frequency Radiation (RFR) exposure from both mobile phones and mobile
towers may have possible thermal/non-thermal effects.
Radiation level by a Mobile Base Station Sites
• Every site radiates electro-magnetic power, one of the factor for level of
radiation depends upon EIRP of site
• More number of Sites may lead to more power intensity in the nearby area, if
power of sites remains same
• More number of antennas, may lead to more power density, if power of each
antenna is same or higher than previous case and type of antenna is same.
• The power level varies with the distance from the nearby towers , it reduces with
distance.

Self Certification by Operators
 Mobile Service Operator may self
certify their BTS for compliance of
above limits after assessment
estimated levels of EMR in the up to
20 meters radius of the BTS based
on appropriate methods
63

STAND-OFF DISTANCES
 Distance from antenna surface to location where EMF
environment is below the occupational (controlled
environment) exposure limits.
 Conservative Estimate - based on maximum
power continuously delivered to antenna
 Briefly passing within the “Stand-Off Distance” will
not be hazardous since exposure limits are time-
averaged and higher exposures are allowed for brief
periods.
 KEEP MOVING PAST ANTENNAS
Stand-off” distances to transmitting
antennas

What Is the Future of Research?
 Better methods to measure and quantify
RF exposure (e.g., is a 10-minute call the
same as 10, 1-minute calls?)
 Better models to estimate SAR away from
the surface
 Identifying the cellular target of RF-EMR
 Well-designed prospective cohort studies
to evaluate cancer, reproduction,
interference, etc.

EMI Compliance
Approaches and Techniques in the deployment of Mobile
Communication Antennas
J.Santhanakrishnan
Formerly Deputy General Manager
BSNL
Chennai.
eMail:bsnljsk@gmail.com
Mobile: 9444001323

Questions?
If you have questions, please don’t
hesitate to contact me:
J.Santhanakrishnan
bsnljsk@gmail.com
Mobile : 9444001323

Reference Slides
5/1/2021 EMF Safety for Wireless system 77

Definitions
1. Electric Fields: Electric fields are a result of the potential difference between two points.
These fields influence the motion of other charges when they are within this field. The units
used when indicating the electric field strength is volt per metre (V/m).
2. Magnetic Fields: The flow of electric charges results in the formation of a magnetic field.
This field influences the motion of moving charges. The units used when indicating the
magnetic field strength is ampere per metre (A/m).
3. Radiation: Radiation describes how energy can be transferred from one point to another.
Other methods of energy transfer are conduction and convection. Electromagnetic Radiation /
Energy EMR (EME) is a wave consisting of time-varying electric and magnetic field components
that travel or radiate through space. EME travels at a constant speed of 300,000,000 or 3 x
108 metres per second (speed of light).
There are both natural and numerous artificial sources of EME. These oscillating fields interact
variously with biological material (ie animals, plants, cells and the human body). To be able to
understand how this radiation interacts with tissue, a basic understanding of its properties is
needed.
EMF can be represented by:
• Wavelength (λ ) the distance between successive crests or troughs of the wave.
• Frequency (f) the number of waves that pass a given point in a given time, typically
1second, Hertz (Hz).
These two parameters are related by the expression: c = λ f where c is equal to the speed of
light C = 300/f where f is in MHz

Definitions
4. Power Density: Power flux- density is the power per unit area normal to the direction of
Electromagnetic wave propagation, usually expressed in unit watt per meter square (W/Sq.m). : For plane
waves, power flux-density, electric field strength (E), and magnetic field strength (H) are related by the
intrinsic impedance of free space, η0= 377 ῼ In particular,
S= E2/ η0 = η0 H2 =EH
Where E and H are expressed in units of V/m and A/m, respectively, and S in units of W/m2. Although
many survey instruments indicate power density units, the actual quantities E or H.
5. Specific Absorption Rate (SAR): SAR is a measure of the rate at which energy is absorbed by the
body when exposed to a radio frequency (RF) electromagnetic field. It is defined as the power absorbed
per mass of tissue and has units of watts per kilogram (W/kg). SAR is usually averaged either over the
whole body, or over a small sample volume (typically 1 g or 10 g of tissue). The value cited is then the
maximum level measured in the body part studied over the stated volume or mass. For mobile phones,
and other such hand-held devices, the SAR limit is 2 W/kg averaged over 10 g of tissue (IEC 62209-1).
6. Occupational/ Controlled Exposure: Occupational/ Controlled exposure applies to the situations
where persons are exposed as a consequence of their employment and which those persons who are
exposed have been made fully aware of the potential for exposure and can exercise control over their
exposure. It also applies where the exposure is of transient nature as a result of incidental passage
through a location where exposure limits may be above the general population / uncontrolled limit as long
as the exposed person has been made fully aware of the potential for the exposure and can exercise
control over his or her exposure by leaving the area or by some other appropriate means
7. General public: Normal public under exposed to EMF field of Cellsite
8. ICNIRP: International Commission on Non-Ionizing Radiation Protection

9. Ionizing radiation: EM waves are energetic enough to detach electrons from atoms or molecules,
ionizing them.
10.Non-ionizing radiation: Refers to any type of electromagnetic radiation that does not carry enough
energy per quantum to ionize atoms or molecules; here electromagnetic radiation has sufficient energy
only for excitation, the movement of an electron to a higher energy state.
11. Electronic medical devices other than body-worn/implanted: Electronic medical devices (e.g.
equipment such as infusion pumps, etc.) may not work normally when in high-level RF field
12. Operation of Terminal Equipment in aircraft: Terminal Equipment used or switched-on aboard an
aircraft may produce RF fields with the potential to interfere with aircraft systems.
13. Inadvertent ignition of flammable atmosphere : In flammable atmospheres, high level RF fields
may cause sparking which may cause inadvertent ignition
14. Radiofrequencies (RF) : Are commonly defined as electromagnetic energy with frequencies between
0.003 MHz to 300,000 MHz. Wireless services, commercial radio and TV broadcast all fall within this
frequency range.
15. Microwave: The term “microwave” describes a subset of radiofrequencies, generally defined as those
above 300 MHz. The term “microwave” often can elicit fear similar to the term “radiation”. What some fail
to realize is that microwaves are not more-hazardous than RF. They are indeed RF.
Definitions

16. Heating Effect: Absorption of RF energy in the body causes an increase in temperature. Hence, when
the body absorbs sufficient RF energy there is a resultant heating effect. A change of 2 – 3 Celsius of the
body’s internal core temperature can lead to significant health problems and even death.
17. Effect on Cataracts: Human eyes, in particular the cornea and the lens have a reduced cooling
capacity due to limited blood flow. This makes them more susceptible to RF radiation than other parts of
the body because they are unable to dissipate the heat as easily. For effects to occur the following levels
of exposure are required
• Cataracts from long term exposure to levels greater than 100 mW/cm2 for frequency range 800MHz to
10GHz
• Corneal Lesions – Continuous wave – greater than 30 100 mW/cm2 and pulsed wave greater than 10
mW/cm2
• Effects on the retina – Greater than 50 mW/cm2
18. Ankle Currents: At frequencies of 40 – 80 MHz, the induction of electrical current is at its greatest
near the ground. The ankles have a small conductance path because of their low wet tissue cross-
sectional area. Therefore, the heating of the ankle tissue due to resistive losses is more prevalent.
19. RF Shocks and Burns: Unearthed metal objects may act as an antenna to RF radiation and induce
quite high potential charges. Normally, this effect occurs at frequencies between 100 kHz to 110 MHz.
These induced charges may be high enough to cause arcing resulting in RF burns or shocks when the
metal is touched and earthing occurs.
20. Auditory Clicks :Pulse modulated fields (200 MHz to 6.5 GHz) have produced a recognisable
biological effect. This effect has been described as a buzzing, clicking or popping sound. This effect is not
considered harmful but long-term exposure may lead to stress related problems.
Definitions

Myths & Facts
Myths Facts
1. Mobile phones increase the
of Brain Cancer, Brain tumor
etc
Till date there is absolutely no
evidence of such kind.
2. Mobile phones are powerful
enough to cook your brain
No.
Output of mobile phones is less than
1 Watt
3. RF radiations emitted by
Mobile Base Station are
ionising
RF radiations emitted by the Mobile
Base Station lie in the non-ionising
part of electromagnetic spectrum
4. Exposure to the level of RF
radiations emitted by the
base station can be
hazardous to health
The average level of RF exposure
from the base station is only 0.002%
of the recommended guidelines
EMF emissions from mobile phones and base stations are some hundreds of
times lower than the levels at which the first health effects begin to be
established

EMF Environment – Working at Ground Level
Around Antenna Support Structures
 Typically, EMF environments on the ground around antenna support
structures are below safety limits
 At some antenna installations, there may be certain areas on the
ground where EMF levels could exceed safety limits
 EMF Environment around transmitting antennas depends on:
 Actual power input to antenna
 Antenna up-time or duty cycle
 Antenna type
 Mounting height of transmitting surface of antenna
 Distance to transmitting surface (radiating portion) of antenna
 Transmitting status of and distance to nearby co-located antennas

Sa college emi compliance approaches and techniques in the deployment of mobile communication antennas211120

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (19)

Similaire à Sa college emi compliance approaches and techniques in the deployment of mobile communication antennas211120

Similaire à Sa college emi compliance approaches and techniques in the deployment of mobile communication antennas211120 (20)

Dernier

Dernier (20)

Sa college emi compliance approaches and techniques in the deployment of mobile communication antennas211120

Notes de l'éditeur