IEC 61156-11:2023

Overview

IEC 61156-11:2023 is the sectional specification for symmetrical single pair cables intended for horizontal floor wiring with transmission characteristics specified up to 1.25 GHz. It covers cable design, electrical and mechanical characteristics, environmental performance and test methods for single balanced pair applications in office, home and industrial environments. The standard supports cabling used with systems referenced in ISO/IEC 11801-1, including example applications such as 1000BASE‑T1 (see ISO/IEC TR 11801‑9906). Two performance types are defined: T1‑C (up to 600 MHz) and T1‑D (up to 1.25 GHz). Depending on the installation MICE environment, either unscreened or screened cables can be specified. Annex A provides a blank detail specification for customization.

Key topics and requirements

• Cable construction and materials: conductor, insulation, cable element, screening options, sheath and identification requirements.
• Electrical characteristics: conductor resistance and unbalance, mutual capacitance and capacitance unbalance, impedance, attenuation, phase velocity, delay skew, and return loss.
• Electromagnetic performance: transfer impedance, coupling attenuation, low‑frequency coupling attenuation, alien (exogenous) near‑end crosstalk (PS ANEXT) and far‑end crosstalk (PS AACR‑F).
• Mechanical tests: dimensional checks, tensile and elongation tests, crush, impact, bending and repeated bending, vibration, shock and bump tests.
• Environmental tests: thermal ageing, cold bend, damp heat, solar radiation, solvents, salt mist, water immersion, flame propagation, smoke and halogen gas evolution.
• Bundled cable behaviour: NEXT, ACR‑F and crosstalk requirements for pairs sharing a sheath or installed in bundles.
• Test tables and equations: transfer impedance tables, coupling attenuation requirements and attenuation equation constants to support verification.

Applications

• Structured horizontal floor cabling in commercial offices, residential installations and industrial sites.
• Automotive and industrial single‑pair Ethernet links (e.g., 1000BASE‑T1) where higher-frequency single-pair performance is required.
• Environments requiring either screened or unscreened single-pair solutions based on MICE (mechanical, ingress, climatic, electromagnetic) considerations.
• Use in horizontal channels compliant with ISO/IEC 11801-1 topologies.

Who should use this standard

• Cable manufacturers and component designers preparing product specifications and test plans.
• System integrators, network designers and installers specifying horizontal cabling for new and renovated buildings.
• Test labs and certification bodies validating single‑pair cable performance.
• Specification writers and consultants creating detail specifications (use Annex A as a template).

Related standards

• ISO/IEC 11801‑1 - Generic cabling for customer premises (horizontal cabling).
• ISO/IEC TR 11801‑9906 - Example application: 1000BASE‑T1.
• Other parts of the IEC 61156 series covering multicore and balanced pair/quad cables.

Keywords: IEC 61156-11:2023, symmetrical single pair cables, horizontal floor wiring, 1.25 GHz, T1‑C, T1‑D, screened cable, unscreened cable, coupling attenuation, ANEXT, AACR‑F.