International Telecommunication Union Geneva, July 2009 Electrical Safety and Electromagnetic Compatibility Ahmed ZEDDAM, ITU-T SG 5 Chairman (France Telecom) Claude MONEY Rapporteur of Q6/5 (Swisscom) ITU Consultation on Conformance Assessment and Interoperability Testing (Geneva, July 2009)
International Telecommunication Union Geneva, July Outline of the presentation ITU-T SG5 mandate and objectives DamagesInjuries Protection & Safety issues : Avoiding Damages and Injuries to people disturbances EMC issue : Limiting disturbances to and from telecommunication systems Guidance support to developing countries Human exposure to EMFs Guidance for the telecommunication sector and support to developing countries (Resolution 72)
International Telecommunication Union Geneva, July 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; health effects connected with electromagnetic fields 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 existing copper network outside plant and related indoor installations. Studies on ICT & Climate Change In this field, ITU-T SG 5 is the most experienced and competent standardization body
International Telecommunication Union Geneva, July Meaning of the Mandate: Example damages or disturbances injury to people health effect 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 MDF Switching equipment Subscriber premises Remote site Telecommunication centre Lightning Power line Telecom line Mobile phone Radio station
International Telecommunication Union Geneva, July SG 5 structure WP 1/5 (Resistibility) Equipment Resistibility Lightning protection Earthing & Bonding Electromagnetic interference from power and traction systems Safety WP 2/5 (EMC) Human exposure to e.m. fields EMC Emission Immunity Electromagne tic security WP 3/5 Climate change ICT & climate change Methodology Power feeding systems Energy efficiency Environmental protection, recycling
International Telecommunication Union Geneva, July Objective Study electromagnetic phenomena to define PROTECTIVE MEASURES and/or INSTALLATION TECHNIQUES by means : Recommendations: K-series DirectivesHandbooks Lightning Handbook Earthing Handbook Measuring Handbook Mitigation Handbook Recommendations for limiting the RISK of: Damages Damages to telecommunication installations and equipments Disturbances Disturbances to and from telecommunication systems Injury to people
International Telecommunication Union Geneva, July Outline of the presentation ITU-T SG5 mandate and objectives DamagesInjuries Protection & Safety issues : Avoiding Damages and Injuries to people disturbances EMC issue : Limiting disturbances to and from telecommunication systems Guidance support to developing countries Human exposure to EMFs Guidance for the telecommunication sector and support to developing countries (Resolution 72)
International Telecommunication Union Geneva, July 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
International Telecommunication Union Geneva, July Resistibility and Protection resistibility 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
International Telecommunication Union Geneva, July 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
International Telecommunication Union Geneva, July Equipment resistibility requirements Customers premises K.20 K.45K.21 Telecom centres Access Network K.44 Test methods Equipments have to work in many different operators environments. However, theres 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
International Telecommunication Union Geneva, July 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, performance criteria are defined Damages
International Telecommunication Union Geneva, July 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
International Telecommunication Union Geneva, July 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
International Telecommunication Union Geneva, July Example: Recommendation K.57 Protection measures for radio base stations sited on power line towers RBS cabinet between the legs of the tower RBS antenna and the elevated cabinet Recommendation K.57 (09/2003, Geneva): The CIGRE Technical Brochure N° 266
International Telecommunication Union Geneva, July Outline of the presentation ITU-T SG5 mandate and objectives Protection & Safety issues: Avoiding Damages and Injuries to people disturbances EMC issue : Limiting disturbances to and from telecommunication systems Guidance support to developing countries Human exposure to EMFs Guidance for the telecommunication sector and support to developing countries (Resolution 72)
International Telecommunication Union Geneva, July 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
International Telecommunication Union Geneva, July 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 emission2. ESD3. EFT Classification based on these 3 tests: Class I: Equipment suitable Class II: Equipment Acceptable Class III: Equipment Not suitable
International Telecommunication Union Geneva, July 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
International Telecommunication Union Geneva, July 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
International Telecommunication Union Geneva, July Outline of the presentation ITU-T SG5 mandate and objectives Protection & Safety issues: Avoiding Damages and Injuries to people disturbances 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)
International Telecommunication Union Geneva, July 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
International Telecommunication Union Geneva, July 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)
International Telecommunication Union Geneva, July Example :Recommendation ITU-T K.70 Mitigation techniques to limit human exposure to EMFs in the vicinity of radiocommunication stations 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
International Telecommunication Union Geneva, July Conclusion Only an incomplete picture of the ITU-T SG5 activities has been presented SG 5 hasnt 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