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1 Motivation
Information and Communication Technology (ICT) equipment and devices are being increasingly networked to satisfy the needs of such things as smart cities and Internet of Things (IoT). Where items are connected with metallic conductors, overvoltage and overcurrent surges resulting from coupled lightning and other electrical stress events may occur. Also, items including semiconductor components are often influenced by particle radiation such as neutrons. If the network items do not have sufficient withstand resistibly to the coupled surge conditions or particle radiations, these events may cause interruption of information transfer, equipment damage or hazardous conditions. ICT equipment should be designed to recover after transmission interruptions, damaged items may impair equipment performance and failed items need repair or replacement, which interrupts operation and creates e-waste.
There are two kinds of methodology to provide cost-effective protective measures in order to improve the telecommunication network's reliability from these events. The first one is protection measures applied to facilities and systems, including earthing and bonding, magnetic shielding and cabling, coordination of SPD system. The other one is specifications and test methods applied to ICT equipment and corresponding protection components and devices. This Question studies measures applicable to equipment and devices/components against the effects by overvoltage and overcurrent including lightning surges, and by particle radiations.
This Question is related directly and indirectly to climate change. The direct relationship is the reduction of e-waste, represented by the significant reduction of equipment replacement due to electric damages, and the need of improved protection levels as storm intensities increase. The indirect relationship is associated to the improved reliability and sustainability of the telecommunication system, which reduces fuel consumption, as people do not need to travel for face-to-face meetings as much when real-time video services are available.
The following deliverables (Recommendations, supplements, handbooks and Directives), in force at the time of approval of this Question, fall under its responsibility:
- ITU-T Recommendation K-series: Protection against interference, K.11, K.12, K.20, K.21, K.28, K.36, K.44, K.45, K.50, K.51, K.55, K.64, K.65, K.69, K.75, K.77, K.82, K.89, K.95, K.96, K.98, K.99, K.102, K.103, K.117, K.118, K.124, K.126, K.128, K.129, K.130, K.131, K.135, K.138, K.139, K.140, K.143, K.144, K.147, K.148;
- K-series Supplements 3; 7, 8, 11, 12, 15, 17, 18, 21, 22, 23, 24, 25, 27, 28, 30, 31;
- Implementers Guides for K.44 and for K.20 + K.21 + K.45 combination;
- Directives, Volume VIII.
2 Questions
The purpose of this Question is to produce new or revised Recommendations or supplements regarding requirements and test methods to achieve resistibility against overvoltages and overcurrents, and also reliability against particle radiations for ICT equipment. Specifications and test methods applicable to protective components and assemblies are also recommended. The resistibility and reliability Recommendations against overvoltages and overcurrents, and particle radiations apply to equipment installed in telecommunications centres, in the access and trunk networks and at customer premises. The protective components and assemblies are related to both telecommunication and power supply circuits of telecommunication equipment and they are intended to mitigate the effects of overvoltages and overcurrents. The sources of overvoltages and overcurrents considered are those that may cause permanent damage and include lightning, electrostatic discharge (ESD), electrical fast transients (EFTs), power induction, and mains power contacts.
Study items to be considered include, but are not limited to:
- New requirements on Ethernet port resistibility testing due to the use of longer cabling connected to this port, often running in outdoor environments (called "BASE-T1 Ethernet" or "single-pair Ethernet");
- Effect of multiple surges (e.g., generated by subsequent lightning strokes) on equipment resistibility and on the performance of surge protective components and devices;
- Effect of fast rising overvoltages (e.g., induced by a nearby lightning flash) on the equipment resistibility;
- Determine equipment resistibility taking into account the effects of new equipment port types connecting to new and different services;
- The protection of mains ports considering the coordination between the primary protector and equipment inherent protection;
- The protection of non-earthed equipment with surge protective components (SPCs) that bridge the safety isolation, which are effective but currently not allowed by IEC safety standards (e.g., IEC 60950-1/IEC 62368-1);
- Review USB 3.0 implementations for correct equipment resistibility levels and recommendations;
- Review Ethernet isolation requirements, including new Power over Ethernet (PoE) non-IEEE 802.3 compliant versions;
- Update the safety Recommendations taking into account the evolution of IEC safety standards (e.g., IEC 60950-1 and IEC 62368-1);
- Effects of induced voltages by electric power and railway lines in normal conditions on safety voltage limits on telecommunication lines;
- Review the test method for coaxial port taking into account IEC 61000-4-5;
- Review the safety aspects of DC Remote Power Feeding System considering the relevant IEC standards;
- Review of protective components requirements in order to include safety requirements (e.g., thermal disconnect switch for metal oxide varistor and fail-safe device for gas discharge tubes);
- Coordination of overcurrent protection components with the system current capability;
- Requirements of surge protective components and devices in order to be compatible with broadband data communications;
- Coordination between surge protective components installed in the same circuit;
- Use of insulation barriers as a means of blocking longitudinal/common-mode voltage surges;
- Transients generated by the operation of switching-type overvoltage protectors;
- Define surge resistibility requirements for broadband fast access to subscriber terminals (G.fast) ports.
- Total design methodologies of ICT equipment/systems for applying soft error countermeasures;
- Requirements for soft error test facilities consisting of particle accelerators to produce neutron irradiation and test procedures for ICT equipment;
- Quality estimation method to find reliability in the real installation based on neutron irradiation test;
- Countermeasures based on the phenomena found in the neutron irradiation test.
NOTE - The issues regarding protective devices for overvoltage and overcurrent are studied in context of specifications, i.e., consideration on its circuit configuration, test methods, performance criteria related to protection of equipment, in this Question. The issues regarding protective devices in contest of "facilities and systems", i.e., consideration as a part of surge protection system taking into account of overvoltage and overcurrent characteristics at each protection environment on power/signal lines, are under the responsibility of Question 1/5 "Electrical protection, reliability, safety, and security of telecommunications/ICT systems".
3 Tasks
Tasks include, but are not limited to:
- Monitor and comprehend the evolution of ICT systems, their safety requirements, and their electrical environments;
- Revise or create K-series Recommendations, supplements, and implementers' guides to provide up to date performance requirements, safety requirements evaluation procedures and application advice for ICT equipment, ICT devices and surge protective component needs;
- When necessary, respond to or create liaisons with other bodies concerning the task force scope topics.
An up-to-date status of work under this Question is contained in the ITU-T SG5 work programme (https://www.itu.int/ITU-T/workprog/wp_search.aspx?sp=18&q=2/5).
4 Relationships
Recommendations:
- ITU-T K-series Recommendations
Questions:
- 1/5, 4/5
Study Groups:
- ITU-T SGs
- ITU-R SGs
- ITU-D SGs
Other bodies:
- IEC (e.g. TC 37, SC 37A, SC 37B, TC 47, TC 64, SC 77B, TC 81, TC 107, TC 108 and TC 109)
- ISO
- CENELEC
- IEEE-PES-SPDC
- ATIS (STEP)
- UL
- ETSI
- JEDEC
WSIS Action Lines:
- C2, C5
Sustainable Development Goals:
- 7, 9
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