Electrical Safety and Electromagnetic Compatibility

1. ITU Consultation on Conformance Assessment and Interoperability Testing (Geneva, 20-21 July 2009) Electrical Safety and Electromagnetic Compatibility Ahmed ZEDDAM, ITU-T SG 5 Chairman (France Telecom) Claude MONEY Rapporteur of Q6/5 (Swisscom)

2. Outline of the presentation • ITU-T SG5 mandate and objectives • Protection & Safety issues :Avoiding Damages and Injuries to people • EMC issue : Limiting disturbances to and from telecommunication systems • Human exposure to EMFs Guidance for the telecommunication sector and support to developing countries(Resolution 72)

3. ITU-T SG 5 • SG 5 Title: “Environment & Climate Change” • SG 5 Mandate Study Group 5 is responsible for : • Studies related to protection of telecommunication networks and equipment from interference and lightning; • Studies related to electromagnetic compatibility (EMC), safety and health effects connected with electromagnetic fields produced by telecommunication installations and devices, including cellular phones; • Studies on the existingcopper network outsideplant and related indoor installations. • Studies on ICT & ClimateChange In this field, ITU-T SG 5 is the most experienced and competent standardization body

4. Meaning of the Mandate: Example Power line Lightning • Telecommunication centre Subscriber premises Remote site Switching equipment MDF Radio station Telecom line Mobile phone Study Electromagnetic Phenomena that can potentially cause damages or disturbances to telecommunication installations or injury to people (telecommunication personnel and service users) as well as health effect to population

5. SG 5 structure • WP 2/5 • (EMC) • Human exposure to e.m. fields • EMC • Emission • Immunity • Electromagnetic security • WP 3/5 • Climate change • ICT & climate change • Methodology • Power feeding systems • Energy efficiency • Environmental protection, recycling WP 1/5 (Resistibility) • Equipment Resistibility • Lightning protection • Earthing & Bonding • Electromagnetic interference from power and traction systems • Safety

6. Objective • Study electromagnetic phenomena to define PROTECTIVE MEASURES and/or INSTALLATION TECHNIQUES by means : • Recommendations: K-series • Directives • Handbooks • Lightning Handbook • Earthing Handbook • Measuring Handbook • Mitigation Handbook • Recommendations for limiting the RISK of: • Damages to telecommunication installations and equipments • Disturbances to and from telecommunication systems • Injury to people

7. Outline of the presentation • ITU-T SG5 mandate and objectives • Protection & Safety issues :Avoiding Damages and Injuries to people • EMC issue : Limiting disturbances to and from telecommunication systems • Human exposure to EMFs Guidance for the telecommunication sector and support to developing countries(Resolution 72)

8. Damages • Sources of damages: • Lightning • Electric Power and Traction systems • Electrostatic discharge (ESD) • The damages can be reduced by: • Equipment resistibility • Installation rules • Protective measures

9. Resistibility and Protection • Preventing equipment damage may require a combination of resistibility and protection • Resistibility is • The ability of the equipment to withstand an over-voltage or over-current • Protection is • The addition of protective measures to prevent damages from larger surges

10. SG 5 role in the equipment protection • SG 5 is unique in over-voltage protection • Defines equipment resistibility requirements • Ensures coordination between equipment and external protections • Evaluates installation practices and their effect on resistibility

11. Equipment resistibility requirements Customer’s premises Access Network Telecom centres K.20 K.45 K.21 K.44 Test methods • Equipments have to work in many different operators’ environments. However, there’s a need for a single environment requirement Relevant Recommendations • Tests: • Impulse tests (Lightning) • Induction tests at power frequencies (16, 50 or 60 Hz) • Power contact tests • Two protection levels: • Basic • Enhanced

12. Resistibility tests • Conformance testing • Testing is performed with the equipment operational and connected to any associated equipment. • Testing is performed for each normal mode of operation e.g. “on hook” and “off hook”. • Testing is performed • Line to line (transverse) • Line to earth (longitudinal) • Port to external port (e.g. Telecommunications to mains port) • For all tests, performancecriteria are defined Damages

13. Protection measures • Installation practices • Multiservice Surge Protective Device (MSPD) if required. Depends on risk assessment • Earthing and bonding • A new Home Network Special Group has recently been established to investigate damages and provide installation guidelines

14. Safety • SG 5 is not the lead working group. This role is held by IEC • However, SG 5 shall be involved when • safety and resistibility are linked e.g. insulation is used as a protection measure • the IEC assumes that the network operator will install protection in lightning prone areas • network operators’ special needs have to be taken into account • Relevant Recommendations • K.50, K.51, K.64, K.75

15. Example: Recommendation K.57 Protection measures for radio base stations sited on power line towers RBS cabinet between the legs of the tower • Recommendation K.57 (09/2003, Geneva):www.itu.int/rec/T-REC-K/e • The CIGRE Technical Brochure N° 266 www.e-cigre.org RBS antenna and the elevated cabinet

16. Outline of the presentation • ITU-T SG5 mandate and objectives • Protection & Safety issues: Avoiding Damages and Injuries to people • EMC issue : Limiting disturbances to and from telecommunication systems • Human exposure to EMFs Guidance for the telecommunication sector and support to developing countries(Resolution 72)

17. Electromagnetic Compatibility • EMC Recommendations of K. series cover: • Definition of environment K.34 • Equipment test/conformance K.43, K.48, K.49, K.63, K.75 • Test/conformance of the network • Emission of networks K.60 • ITU-T SG5 normally refers to basic documents produced by IEC and develops Recommendations on How to apply them in the Telecom environment

18. Example: Recommendation K.63 • Maintaining the suitability of production telecommunications equipment to its intended electromagnetic environment • Recommendation K.63 defines rules on how to execute tests on normal production for checking the compliance with the EMC requirements. • Stability of the product • Support both operator and manufacturer • Rec. K.63 suggests that only 3 tests, performed on a small number of equipments selected at random from a batch, are sufficient to give a good confidence on EMC performance: 1. Radiated emission 2. ESD 3. EFT • Classification based on these 3 tests: • Class I: Equipment “suitable” • Class II: Equipment “Acceptable” • Class III: Equipment “Not suitable”

19. Radiation: why to deal with? • Risk: reduced revenue if the deployment of broad band services is restricted to some areas due to interference to other services • How does interference occur • How to manage this interference problem

20. Radiation • Risk: restricted deployment of broad band services due to interference to other “radio” services • How does interference occur • How to manage this interference problem Example: recommendation K.60 • To be used only in case of radio interference • Gives advice how to solve the interference case: • Defines border between network operator and Authority responsibility

21. Outline of the presentation • ITU-T SG5 mandate and objectives • Protection & Safety issues: Avoiding Damages and Injuries to people • EMC issue : Limiting disturbances to and from telecommunication systems • Human exposure to EMFs Guidance for the telecommunication sector and support to developing countries (Resolution 72)

22. Human exposure to electromagnetic fields (EMF) Question 3/5: Human exposure to electromagnetic fields (EMF) due to radio systems and mobile equipment • Guidance for the telecommunication sector • Collaboration with other standardization bodies (IEC, CENELEC, WHO) in order to avoid duplication of work • Support to developing countries – Resolution 72

23. Relevant ITU-T Recommendations on EMF: • K.52 (2000/2004)Guidance on complying with limits for human exposure to electromagnetic fields • K.61 (2003/2008)Guidance to measurement and numerical prediction of electromagnetic fields for compliance with human exposure limits for telecommunication installations • K.70 (2007) Mitigation techniques to limit human exposure to EMF's in the vicinity of radiocommunication base stations • K. guide (under development) Guide to the Management of Human Exposure to Electromagnetic Fields (EMFs)

24. Example :Recommendation ITU-T K.70 Mitigation techniques to limit human exposure toEMFs in the vicinity ofradiocommunicationstations • Modeling of the transmitting antennas • Importance of the Vertical Radiation Pattern (VRP) • Identification of the main source of radiation • Mitigation techniques in order to reduce radiation level – if required • EMF-estimator – software with the library of examples of the transmitting antennas

25. Conclusion • Only an incomplete picture of the ITU-T SG5 activities has been presented • SG 5 hasn’t produced recommendations for conformance and interoperability testing. However, resistibility recommendations (K.20, K.21, K.44 and K.45) minimize equipment down time (reduction in damages to equipment from lightning and power induction surges) and might be seen as conformance criteria • Furthermore, minimising downtime could be considered a subset of interoperability. • The Recommendations dealing with resistibility conformance would be useful to consider for an ITU mark program