IEC 61156-11:2019

Overview

IEC 61156-11:2019 is the IEC sectional specification for symmetrical single‑pair cables intended for horizontal floor wiring with transmission characteristics up to 600 MHz. It defines cable constructions and test requirements for single twisted‑pair cables designed to support 1 Gbps over a single pair (example application: 1000BASE‑T1, see ISO/IEC TR 11801‑9906). The standard addresses shielded channel use (nominal channel length 40 m) and allows multiple pairs in one sheath when parallel systems are used. A blank detail specification is provided in Annex A.

Key topics and technical requirements

IEC 61156‑11 covers materials, construction, electrical, mechanical and environmental performance, including:

• Cable types and constructions: permitted designs include U/FTP, X/UTP and X/FTP (where X = F, S or SF).
• Electrical characteristics and tests: conductor resistance, resistance unbalance, dielectric strength, insulation resistance, mutual capacitance, capacitance unbalance.
• High‑frequency transmission metrics up to 600 MHz: attenuation, phase/velocity of propagation, delay skew, characteristic impedance, return loss.
• Crosstalk and shielding performance: transfer impedance, coupling attenuation, unbalance attenuation (TCL and EL TCTL), alien near‑end/far‑end crosstalk (PS ANEXT, PS AACR‑F) and bundled‑cable crosstalk behavior.
• Mechanical and durability tests: bending radius, tensile, elongation, crush, impact, shock, vibration and repeated bending.
• Environmental tests: thermal ageing, cold bend, heat shock, damp heat, UV/solar radiation, solvents, salt mist, water immersion, wicking, flame propagation, halogen gas, smoke and toxic gas emission.
• Operational constraints: specified at 20 °C; intended for voltages/currents normally found in communications systems (not for mains low‑impedance sources) and supports low‑voltage remote powering.

Practical applications and users

Who uses IEC 61156‑11:

• Cable manufacturers and R&D teams designing single‑pair shielded cables for 1 Gbps applications
• Test laboratories and QA teams performing certification and compliance testing to IEC 61156‑11
• System integrators, network designers and spec writers deploying horizontal floor wiring in offices, homes and industrial sites
• Product managers and standards engineers specifying physical media for automotive‑grade or industrial single‑pair Ethernet (where applicable) Practical applications include structured horizontal cabling for high‑speed single‑pair Ethernet links, short shielded channels (≈40 m), and installations requiring remote low‑voltage powering.

Related standards

• IEC 61156 series (other parts covering multicore and pair/quad cables)
• ISO/IEC TR 11801‑9906 (example application: 1000BASE‑T1 / single‑pair Ethernet)
• Refer to the normative references in IEC 61156‑11 for full test method cross‑references.

For manufacturers and installers, IEC 61156‑11 provides the test methods and sectional specification needed to deliver reliable single‑pair, high‑bandwidth horizontal cabling.