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ITU-T Workshop on Delivering Good Quality Telecommunication Service in a Safe Environment in Africa (Nairobi, Kenya, 26 July – 27 July 2010 ). EMF ASSESSMENT BY MESEAREMENTS AND CALCULATION (IVORIAN CASE). Guy-Michel KOUAKOU, Vice-chair of study group 5 (ITU-T)
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ITU-T Workshop on Delivering Good Quality Telecommunication Service in a Safe Environment in Africa (Nairobi, Kenya, 26 July – 27 July 2010 ) EMF ASSESSMENT BY MESEAREMENTS AND CALCULATION (IVORIAN CASE) Guy-Michel KOUAKOU, Vice-chair of study group 5 (ITU-T) Deputy-Director of Quality (ATCI)
PLAN • National context • EMF assessment • Flowchart for measurement procedure • Measuring equipment • Post-processing analysis • Some statistics • Conclusion
NATIONAL CONTEXT (1/2) • public concern about the likely effects of electromagnetic fields on health. • Many people are against the deployment of base stations in their neighbourhoods. • No legal protection framework in place for EMF related health issues.
NATIONAL CONTEXT (2/2) • the ATCI which assists the state regarding the protection of property and persons has adopted 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)
EMF ASSESSMENT (1/2) • Measurements campaign was achieved in Abidjan and carried out in the frequency band from 10 KHz to 6 GHz • First step: 105 locations were identified and made a general field assessment • Second step: The whole procedure was executed in the 43 points with the highest level (decision level of 0,3 V/m).
EMF ASSESSMENT (2/2) • In situ measurement duration: almost 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
FLOW CHART Résultats> limites CIPRNI Exigences de protection de la santé respectée Exigences de protection non respectée
MEASURING EQUIPMENTS Boîtier de commutation Sonde tri axe Analyseur de spectre Anritsu MS2721B Champ EM émis par plusieurs services (TV, FM, GSM …) z x y z x y • For case 1: RF radiation meters with isotropic field probes and a dosimeter Sonde isotropique Campmetre large bande ANTENNESA EME SPY 120 (88Mhz - 3Ghz) • Cases 2 & 3: Spectrum Analyser
POST-PROCESSING (1/2) • Measurement uncertainty estimation according to IEC guide: Uncertainty table for case 2 and 3 (for f<3GHz)
POST-PROCESSING (2/2) • Measurements in GSM were done only for the permanent control channel (BCCH). Results have been extrapolated taking into account the case where the trafic is maximum. • This extrapolation to the maximum traffic is calculated by the following formula • Emax = E Control Channel x sqrt (n Transmitters) • n=3 in GSM 900 and n=4 in GSM 1800. These values represent the number of Transmitters generally used in rural areas
RESULT Every measurement was found to have been in compliance with ICNIRP limits. Nairobi, Kenya, 28-29 Juillet 2010
SOME STATISTICS (1/3) Average field level per service • The average field level per service was low (under 0,3 V/m) except for GSM service where the average levels were 1.933 V/m for GSM 900 and 1.608 V/m for GSM 1800
SOME STATISTICS (2/3) Ratio between average value and ICNIRP limits • According to ICNIRP limits. • GSM 900 represent 4.81% • GSM 1800 represent 2.83%
SOME STATISTICS (3/3) Field level distribution per service • For GSM 900 : 93,02 % of field levels was less than 10% of limits value (4,18 V/m) ; • For GSM 1800 : 97,67 % of EM field was less than 10% of limits value (5.68 V/m);
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; • Approval of a gentlemen agreementbetween operators, population and local authorities for base stations deployment; • Data base link to an automatic system for spectrum management .