Connecting the world and beyond

Classification of ITU-T K-series Recommendations

The K. series Recommendation and Supplements are divided into the following topics:

Electrical protection, reliability, safety and security of ICT systems
Protecting equipment and devices against lightning and other electrical events
Human exposure to electromagnetic fields (EMFs) due to digital technologies
Electromagnetic compatibility (EMC) aspects in ICT environment

Electrical protection, reliability, safety and security of ICT systems

K.6 Precautions at crossings
K.7 Protection at crossings
K.8 Separation in the soil between telecommunication cables and earthing system of power facilities
K.9 Protection of telecommunication staff and plant against a large earth potential due to a neighboring electric traction line
K.13 Induced voltages in cables with plastic-insulated conductors
K.14 Provision of a metallic screen in plastic-sheathed cables
K.19 Joint use of trenches and tunnels for telecommunication and power cables
K.26 Protection of telecommunication lines against harmful effects from electric power and electrified railway lines
K.27 Bonding configurations and earthing inside a telecommunication building
K.29 Coordinated protection schemes for telecommunication cables below ground
K.35 Bonding configurations and earthing at remote electronic sites
K.39 Risk assessment of damages to telecommunication sites due to lightning discharges
K.40 Protection against LEMP in telecommunications centres
K.46 Protection of telecommunication lines using metallic symmetric conductors against lightning-induced surges
K.47 Protection of telecommunication lines against direct lightning flashes
K.54 Conducted immunity test method and level at fundamental power frequencies
K.56 Protection of radio base stations against lightning discharges
K.57 Protection measures for radio base stations sited on power line towers
K.66 Protection of customer premises from overvoltages
K.67 Expected surges on telecommunications and signalling networks due to lightning
K.68 Operator responsibilities in the management of electromagnetic interference by power systems on telecommunication systems
K.71 Protection of customer antenna installations
K.72 Protection of telecommunication lines using metallic conductors against lightning: Risk management
K.73 Shielding and bonding for cables between buildings
K.78 High altitude electromagnetic pulse immunity guide for telecommunication centres
K.81 High-power electromagnetic immunity guide for telecommunication systems
K.84 Test methods and guide against information leaks through unintentional electromagnetic emissions
K.85 Requirements for the mitigation of lightning effects on home networks installed in customer premises
K.87 Guide for the application of electromagnetic security requirements - Overview
K.89 Protection of persons inside a structure using telecommunication services provided by metallic conductors against lightning - Risk management
K.97 Lightning protection of distributed base stations
K.101 Shielding factors for lightning protection
K.104 Method for identifying the transfer potential of EPR from HV and/or MV to the earthing system or neutral of LV network
K.105 Lightning protection of photovoltaic power supply system feeding a radio base station
K.107 Method for determining the impedance to earth of earthing systems
K.108 Joint use of poles by telecommunication and solidly earthed power lines
K.109 Installation of telecommunication equipment on utility poles
K.110 Lightning protection of the dedicated transformer for radio base stations
K.111 Protection of surrounding structures of telecommunication towers against lightning
K.112 Lightning protection, earthing and bonding Practical procedures for radio base stations
K.115 Mitigation methods against electromagnetic security threats
K.123 Electromagnetic compatibility requirements for electrical equipment in telecommunication facilities
K.124 Overview of particle radiation effects on telecommunication systems
K.125 Dangerous effects and protective measures against electromagnetic disturbances when an Internet data centre is co-sited with a high-voltage substation
K.130 Neutron irradiation test methods for telecommunication equipment
K.131 Design methodologies for telecommunication systems applying soft error measures
K.134 Protection of small-size telecommunication installations with poor earthing conditions
K.138 Quality estimation methods and application guidelines for mitigation measures based on particle radiation tests
K.139 Reliability requirements for telecommunication systems affected by particle radiation
K.141 Electromagnetic compatibility requirements for information perception equipment
K.142 Lightning protection and earthing of video surveillance systems
K.146 Interference management for telecommunication transmissions over copper lines for signals other than speech
K.150 Information of semiconductor devices required for the design of telecommunication equipment applying soft error mitigation measures
K.151 Electrical safety and lightning protection of medium voltage input and up to ±400 VDC output power system in ICT data centres and telecommunication centres
K.154 Operating telecommunication facilities using lightning strikes data obtained from lightning location systems
K.155 Performance requirements and test methods for surge protective modules used in AC power ports of telecommunication equipment
K.158 Practical guidance for protection of the indoor distribution system for mobile communications in large-scale physical buildings
K Suppl. 5: ITU-T K.81 - Estimation examples of the high-power electromagnetic threat and vulnerability for telecommunication systems
K Suppl. 6: ITU-T K.115 – Measuring shielding effectiveness using normalized site attenuation in free space
K Suppl. 8: Resistibility analysis of 5G systems
K Suppl. 11: ITU-T K.131 - Soft error measures for field programmable gate arrays
K Suppl. 23: Ethernet port surge voltages and currents

protecting equipment and devices against lightning and other electrical events

K.11 Principles of protection against overvoltages and overcurrents
K.12 Characteristics of gas discharge tubes for the protection of telecommunications installations
K.20 Resistibility of telecommunication equipment installed in a telecommunications centre to overvoltages and overcurrents
K.21 Resistibility of telecommunication equipment installed in customer premises to overvoltages and overcurrents
K.28 Parameters of thyristor-based surge protective devices for the protection of telecommunication installations
K.36 Selection of protective devices
K.44 Resistibility tests for telecommunication equipment exposed to overvoltages and overcurrents ? Basic Recommendation
K.45 Resistibility of telecommunication equipment installed in the access and trunk networks to overvoltages and overcurrents
K.50 Safe limits of operating voltages and currents for telecommunication systems powered over the network
K.51 Safety criteria for telecommunication equipment
K.55 Overvoltage and overcurrent requirements for insulation displacement connectors (IDC) terminations
K.64 Safe working practices for outside equipment installed in particular environments
K.65 Overvoltage and overcurrent requirements for termination modules with contacts for test ports or surge protective devices
K.69 Maintenance of protective measures
K.75 Classification of interface for application of standards on resistibility and safety of telecommunication equipment
K.77 Characteristics of metal oxide varistors for the protection of telecommunication installations
K.82 Characteristics and ratings of solid-state, self-restoring overcurrent protectors for the protection of telecommunications installations
K.89 Protection of persons inside a structure using telecommunication services provided by metallic conductors against lightning - Risk management
K.95 Surge parameters of isolating transformers used in telecommunication devices and equipment
K.96 Surge protective components: Overview of surge mitigation functions and technologies
K.98 Overvoltage protection guide for telecommunication equipment installed in customer premises
K.99 Surge protective component application guide - Gas discharge tubes
K.102 Parameters of fixed-voltage thyristor overvoltage protector components used for the protection of telecommunication installations
K.103 Surge protective component application guide - Silicon PN junction components
K.117 Primary protector parameters for the surge protection of equipment Ethernet ports
K.118 Requirements for lightning protection of fibre to the distribution point equipment
K.119 Conformance assessment of radio base stations regarding lightning protection and earthing
K.120 Lightning protection and earthing of a miniature base station
K.126 Surge protective component application guide - High frequency signal isolation transformers
K.128 Surge protective component application guide - metal oxide varistor (MOV) components
K.129 Characteristics and ratings of silicon PN junction voltage clamping components used for the protection of telecommunication installations
K.135 Technical parameters for residual current operated protective devices with automatic reclosing feature for telecom applications
K.140 Surge protective component application guide – Fuses
K.143 Guidance on safety relating to the use of surge protective devices and surge protective components in telecommunication terminal equipment
K.144 Surge protective component application guide - Self-restoring thermally activated overcurrent protectors
K.147 Ethernet port resistibility testing for overvoltages and overcurrents
K.148 Multiservice surge protective device application guide
K Suppl. 3: ITU-T K.20, K.21, K.45, K.82 - Additional criteria to protect telecommunication cabling during a power cross event
K Suppl. 7: ITU-T K.44 – AC supply configurations
K Suppl. 12: ITU-T K.51 – Potential hazards of narrow pin spacing in connectors
K Suppl. 17: ITU-T K.44 – Test conditions and methods information
K Suppl. 18: ITU-T K.44 – Causes of telecommunication system overvoltage and overcurrent conditions and their expected levels
K Suppl. 21: ITU-T K.21 - Rationale for setting resistibility requirements of telecommunication equipment installed in customer premises against lightning
K Suppl. 22: ITU-T K.45 - Rationale for setting resistibility requirements of telecommunication equipment installed in the access and trunk networks against lightning
K Suppl. 24: ITU-T K.20 - Rationale for setting resistibility requirements of telecommunication equipment installed in a telecommunication centre against lightning
K Suppl. 25: ITU-T K.117 - Long reach single twisted-pair Ethernet resistibility testing
K Suppl. 27: The 100 kHz ring wave generator
K Suppl. 28: Electric shock and related terms and definitions
K Suppl. 30: ITU-T K.118 - Requirements for lightning protection of fibre to the distribution point equipment - Overview
K Suppl. 31: ITU-T K.118 – Requirements for lightning protection of fibre to the distribution point equipment – Modelling earth potential rise

Human exposure to electromagnetic fields (EMFs) due to digital technologies

K.52 Guidance on complying with limits for human exposure to electromagnetic fields
K.61 Guidance on measurement and numerical prediction of electromagnetic fields for compliance with human exposure limits for telecommunication installations
K.70 Mitigation techniques to limit human exposure to EMFs in the vicinity of radiocommunication stations
K.83 Monitoring of electromagnetic field levels
K.90 Evaluation techniques and working procedures for compliance with exposure limits of network operator personnel to power-frequency electromagnetic fields
K.91 Guidance for assessment, evaluation and monitoring of human exposure to radio frequency electromagnetic fields
K.100 Measurement of radio frequency electromagnetic fields to determine compliance with human exposure limits when a base station is put into service
K.113 Generation of radiofrequency electromagnetic field level maps
K.121 Guidance on the environmental management for compliance with radio frequency EMF limits for radiocommunication base stations
K.122 Exposure levels in close proximity of radiocommunication antennas
K.145 Assessment and management of compliance with radio frequency electromagnetic field exposure limits for workers at radiocommunication sites and facilities
K.153 Guidance on determining the compliance boundaries (exclusion zones) of radio transmitter installations
K.156 Time and spatial averaging in RF-EMF exposure assessment
K.160 Assessment of human exposure to radiofrequency electromagnetic fields from wireless communication devices operating close to the human body
K Suppl. 1 Guide on electromagnetic fields and health
K Suppl. 4 Electromagnetic field considerations in smart sustainable cities
K Suppl. 9: 5G technology and human exposure to radiofrequency electromagnetic fields
K Suppl. 13: Radiofrequency electromagnetic field (RF-EMF) exposure levels from mobile and portable devices during different conditions of use
K Suppl. 14: The impact of RF-EMF exposure limits stricter than the ICNIRP or IEEE guidelines on 4G and 5G mobile network deployment
K Suppl. 16: Electromagnetic field compliance assessments for 5G wireless networks
K Suppl. 19: Electromagnetic field (EMF) strength inside underground railway trains
K Suppl. 20: Supplement on radiofrequency exposure evaluation around underground base stations
K Suppl. 29: Electromagnetic field strength inside and outside of electric vehicles using wireless power transfer technology
K Suppl. 32: Case studies of radio frequency- electromagnetic field (RF-EMF) assessment

Electromagnetic compatibility (EMC) aspects in ICT environment

K.10 Low frequency interference due to unbalance about earth of telecommunication equipment
K.18 Calculation of voltage induced into telecommunication lines from radio station broadcasts and methods of reducing interference
K.23 Types of induced noise and description of noise voltage parameters for ISDN basic user networks
K.24 Method for measuring radio-frequency induced noise on telecommunications pairs
K.34 Classification of electromagnetic environmental conditions for telecommunication equipment ? Basic EMC Recommendation
K.37 Low and high frequency EMC mitigation techniques for telecommunication installations and systems - Basic EMC Recommendation
K.38 Radiated emission test procedure for physically large systems
K.42 Preparation of emission and immunity requirements for telecommunication equipment - General principles
K.49 Test requirements and performance criteria for voice terminal telephones subject to disturbance from digital mobile telecommunications systems
K.58 EMC, resistibility and safety requirements and guidance for determining responsibility under co- located information and communication technology installations
K.59 EMC, resistibility and safety requirements and procedures for connection to unbundled cables
K.60 Emission levels and test methods for wireline telecommunication networks to minimize electromagnetic disturbance of radio services
K.62 System level radiated emissions compliance using mathematical modelling
K.63 Maintaining the suitability of production telecommunications equipment to its intended electromagnetic environment
K.74 EMC, resistibility and safety requirements for home network devices
K.76 EMC requirements for telecommunication network equipment (9 kHz-150 kHz)
K.79 Electromagnetic characterization of the radiated environment in the 2.4 GHz ISM band
K.80 EMC requirements for telecommunication network equipment (1 GHz - 6 GHz)
K.86 Method for measuring longitudinal conversion loss (9 kHz - 30 MHz)
K.92 Conducted and radiated electromagnetic environment in home networking
K.93 Immunity of home network devices to electromagnetic disturbances
K.94 Mutual disturbance test method for evaluating performance degradation of converged terminal devices
K.106 Techniques to mitigate interference between radio devices and cable or equipment connected to wired broadband networks
K.114 Electromagnetic compatibility requirements and measurement methods for digital cellular mobile communication base station equipment
K.116 Electromagnetic compatibility requirements and test methods for radio telecommunication terminal equipment
K.127 Immunity requirements for telecommunication equipment in close proximity use of wireless devices
K.132 Electromagnetic compatibility requirements of electromagnetic disturbances from lighting equipment located in telecommunication facilities
K.133 Electromagnetic environment of body-worn equipment in the 2.4 GHz and 13.56 MHz industrial, scientific and medical band
K.136 Electromagnetic compatibility requirements for radio telecommunication equipment
K.137 Electromagnetic compatibility requirements and measurement methods for wire-line telecommunication network equipment
K.157 Electromagnetic compatibility requirements and test methods for satellite communication terminal equipment
K.159 Electromagnetic compatibility requirements and measurement methods for equipment and installations in outdoor applications using power line communication
K.149 Passive intermodulation test methods of array antenna systems in mobile communication systems
K.152: Electromagnetic compatibility requirements for power equipment in telecommunication facilities
K Suppl. 10: Analysis of electromagnetic compatibility aspects and definition of requirements for 5G mobile systems
K Suppl. 26: ITU-T K.114 - Analysis of electromagnetic compatibility requirements and test methods of 5G active antenna system base stations


Electrical protection, reliability, safety and security of ICT systems	Protecting equipment and devices against lightning and other electrical events	Human exposure to electromagnetic fields (EMFs) due to digital technologies	Electromagnetic compatibility (EMC) aspects in ICT environment

Connecting the world and beyond

Classification of ITU-T K-series Recommendations

​Electrical protection, reliability, safety and security of ICT systems

​Electrical protection, reliability, safety and security of ICT systems

​protecting equipment and devices against lightning and other electrical​​ events

​Human exposure to electromagnetic fields (EMFs) due to digital technologies​

Electromagnetic compatibility (EMC) aspects in ICT environment​​

Electrical protection, reliability, safety and security of ICT systems

Electrical protection, reliability, safety and security of ICT systems

protecting equipment and devices against lightning and other electrical events

Human exposure to electromagnetic fields (EMFs) due to digital technologies

Electromagnetic compatibility (EMC) aspects in ICT environment