EMF ASSESSMENT BY MESEAREMENTS AND CALCULATION (IVORIAN CASE)

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EMF ASSESSMENT BY MESEAREMENTS AND CALCULATION
(IVORIAN CASE)
ITU-T Workshop on Delivering Good Quality
Telecommunication Service in a Safe Environment
in Africa (Nairobi, Kenya, 26 July 27 July
2010 )

• Guy-Michel KOUAKOU,
• Vice-chair of study group 5 (ITU-T)
• Deputy-Director of Quality (ATCI)

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PLAN

• National context
• EMF assessment
• Flowchart for measurement procedure
• Measuring equipment
• Post-processing analysis
• Some statistics
• Conclusion

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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.

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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)

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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).

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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

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FLOW CHART
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MEASURING EQUIPMENTS

• 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

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POST-PROCESSING (1/2)

• Measurement uncertainty estimation according to
  IEC guide

Source d'erreur Valeurd'incertitude () Distribution deprobabilité Diviseur Ci Incertitudestandard ()
Appareillage de mesure Appareillage de mesure Appareillage de mesure Appareillage de mesure Appareillage de mesure Appareillage de mesure
Isotropie 21,62 Normale 2 1 0,85
Linéarité 12,20 Rectangulaire 1,73 1 0,58
Platitude en fréquence   Normale   1  
Température   Normale   1  
câble 2,33 Normale 2 1 0,10
Facteur d'antenne 18,85 Normale 2 1 0,75
           
Incertitude standardcombinée 15,88        
Incertitude étendue(intervalle de confiance de 95) 31,76 Normale     ue 2 uc
Uncertainty table for case 2 and 3 (for flt3GHz)
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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)

• n3 in GSM 900 and n4 in GSM 1800. These values
  represent the number of Transmitters generally
  used in rural areas

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RESULT
Every measurement was found to have been in
compliance with ICNIRP limits.
Nairobi, Kenya, 28-29 Juillet 2010
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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

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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

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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)

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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
• Approval of a gentlemen agreement between
  operators, population and local authorities for
  base stations deployment
• Data base link to an automatic system for
  spectrum management .