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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)
PLAN • National context • EMF assessment • Flowchart for measurement • Measuring equipment • Post-processing analysis • Some statistics • Conclusion
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.
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)
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.
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
FLOW CHART Résultats> limites CIPRNI Exigences de protection de la santé respectée Exigences de protection non respectée
MEASURING EQUIPMENT EMR 300 W/G (10 Khz - 3 Ghz) 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 ANTENNESA EME SPY 120 (88Mhz - 3Ghz) Cases 2 & 3: Spectrum Analyser
POST-PROCESSING (1/2) • Measurement uncertainty estimation according to IEC guide: • For each case equipment uncertainty was taken into account. IEC “Guide to the expression of uncertainty in measurement Ed. 1, 1995
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.
RESULT Every measurement was found to have been in compliance with ICNIRP limits.
SOME STATISTICS (1/3) Average field level per service 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
SOME STATISTICS (2/3) Ratio between average value and ICNIRP limits • According to ICNIRP limits. GSM 900 represent 3.31% and GSM 1800 represent 4.70%
SOME STATISTICS (3/3) Field level distribution per service 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);
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.