Multicore and symmetrical pair/quad cables for digital communications - Part 12: Symmetrical single pair cables with transmission characteristics up to 1,25 GHz - Work area wiring - Sectional specification

IEC 61156-12:2025 specifies cables intended to be used for single balanced pair cabling for office, home and industrial application described in ISO/IEC 11801-1:2017 and ISO/IEC 11801:2017/AMD1 . An example of existing application is 1000BASE-T1, see ISO/IEC TR 11801 9906. The transmission characteristics of these cables are specified up to a frequency of 1,25 GHz and at a temperature of 20 °C. The T1-B type cable is specified from 0,1 MHz to 600 MHz, the T1 C type cable from 0,1 MHz to 1,25 GHz. Depending on the MICE environment and the installation conditions, either unscreened or screened cables can be used. A blank detail specification can be found in Annex A. This second edition cancels and replaces the first edition published in 2021. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous edition:

a) additional cable type in support of T1-C generic single pair cabling up to 1,25 GHz;

b) introduction of low frequency coupling attenuation as an integral parameter describing screening efficiency at frequencies below 30 MHz.