ITU FORUM ON IMPLEMENTATION OF
DECISIONS OF WTSA-08
(Accra, Ghana, 16-17 June 2009)
EMF ASSESSMENT BY MESEAREMENTS
AND CALCULATION
(IVORIAN CASE)
Guy-Michel KOUAKOU,
Vice-chair of study group 5 (ITU-T)
Head of standardization (ATCI)
Accra, Ghana, 16-17 June 2009
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PLAN
National context
EMF assessment
Flowchart for measurement
Measuring equipment
Post-processing analysis
Some statistics
Conclusion
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NATIONAL CONTEXT (1/2)
Major public concerns, misinformation
about EMF health related issues and
particularly EMF effects from base
stations.
Many people are against the
installation and deployment of base
stations in their neighbourhoods.
No legal protection framework in place
for EMF related health issues.
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NATIONAL CONTEXT (2/2)
ATCI (National Regulatory Authority)
ensures the need to protect human
health by adopting international
standards such as:
ITU-T recommendations for compliance
and estimation of EMF (K.52, K.70)
ICNIRP (International Commission on
Non-Ionizing Radiation Protection)
recommendation for exposure limits
CEPT recommendation for measurement
procedures (ECC(02) 04 revised)
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EMF ASSESSMENT (1/2)
Measurements campaign in the town of
Abidjan (the capital) were carried out in
the 10 KHz to 6 GHz band
First step: 103 locations were identified
but later restricted to 43 using a
decision level of 0.3 v/m.
EMF Estimation for these locations were
carried out using the EMF estimator
(K.70) and technical characteristics of
base stations at the various points.
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EMF ASSESSMENT (2/2)
In situ measurement: about 3 hours
per location (1 month for all locations)
some words about measurement
protocol
Based on three cases;
Case 1 for quick overview to find the point
where the field is higher (1.1, 1.5, 1.7)
Cases 2 & 3 for detailed investigation which
allow to scan variable frequency band to
deal with specific services
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FLOW CHART
Exigences de protection de la santé
respectée
Accra, Ghana, 16-17
June
2009 non respectée
Exigences
de protection
Résultats> limites
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MEASURING EQUIPMENT
For case 1: RF radiation meters with isotropic field probes and a
dosimeter
ANTENNESA EME SPY 120 (88Mhz - 3Ghz)
EMR 300 W/G (10 Khz - 3 Ghz)
Cases 2 & 3: Spectrum Analyser
Champ EM émis par
plusieurs services
(TV, FM, GSM z…)
Boîtier de
commutation
Sonde tri axe
Analyseur de
spectre
Anritsu
MS2721B
x
x
y
Accra, Ghana, 16-17 June 2009
y
z
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POST-PROCESSING (1/2)
Measurement uncertainty estimation according
to IEC guide:
For each case equipment uncertainty was
taken into account.
CAS 2
Uncertainty of xi
Input quantity
Value
(dB)
Antenna Factor
2,00
Cable
0,20
isotropy
1,70
Receiver
2,00
distribution
U(Xi)(
%)
Ci
(CiU(Xi))2(%)
normal
25,89
1,00
12,95
2,33
1,00
1,16
21,62
1,00
12,48
25,89
1,00
12,95
rectangular
Combined standard
uncertainty (66% )
21,29
Expanded uncertainty
(95 %)
41,74
IEC “Guide to the expression of uncertainty in measurement Ed. 1, 1995
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POST-PROCESSING (2/2)
GSM measurement extrapolation was
considered for maximum possible traffic.
Measurements were done only for the
permanent control channel.
The extrapolation to the maximum traffic is
then calculated by the following formula
Emax = E Control Channel x sqrt (n Transmitters)
The determination of « n » was done in
accordance with typical base stations
configurations.
For each location an extrapolation factor was
estimated.
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RESULT
Every measurement was found
to have been in compliance
with ICNIRP limits.
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SOME STATISTICS (1/3)
Average field level per service
HF
E(V/m)
PMR
FM
3
2,669
PMR-BALISE
TV
GSM 900
2
1,336
RADARS -DAB
GSM 1800
DECT
1
0,720
0,241
RADARS-BLR-FH
0,378
0,312
0,015
Exploration satellite,
Radiolocalisation
0,033
0,023
0,042
0,044
0
The average field level per service was low (under
1V/m) except for GSM service where the average
levels were 1.336 V/m for GSM 900 and 2.67 V/m
for GSM 1800
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SOME STATISTICS (2/3)
Ratio between average value and ICNIRP limits
HF
PMR
E(V/m)
FM
10%
PMR-BALISE
TV
8%
GSM 900
6%
4,70%
RADARS -DAB
GSM 1800
4%
3,31%
2,57%
DECT
0,86%
RADARS-BLR-FH
Exploration satellite,
Radiolocalisation
2%
0,05%
1,12%
0,12%
0,05%
0,07% 0,62%
0%
According to ICNIRP limits.
GSM 900 represent 3.31%
and GSM 1800 represent 4.70%
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0,07%
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SOME STATISTICS (3/3)
Field level distribution per service
Exploration
satellite,
Radiolocalisation
RADARS-BLR-FH
DECT
GSM 1800
RADARS -DAB
GSM 900
TV Bande IV et V
2%< niveau < 5%
PMR-BALISE
5%< niveau < 10%
Radio FM
PMR
10%< niveau < 100%
service HF
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
1%< niveau < 2%
< 1% de la valeur limite
For GSM 900 : 98 % of field levels was less than 10%
of limits value (4 V/m) ;
For GSM 1800 : 89 % of EM field was less than 10% of
limits value (5.68 V/m);
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CONCLUSION
ATCI will work with GSM operators to
reduce the level of exposure (mitigation
techniques proposed by recommendation
ITU-T K.70).
Use of EMF estimator to assess the
compliance of base stations before their
installation.
Ongoing works:
Assessment of base stations compliance by
measurements in each sensitive location;
Preparation of a gentlement agreement between
operators, consumers and local authorities for base
stations deployment;
Data base for all base stations available on request
for public information.
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