Measuring Cat 8.1: Caution Required!
Phenomenal: 2 Gigahertz
Field measurements once network cabling has been completed are part of the routine tasks of installers. This does not change with modern Class I/Cat. 8.1 cabling. In principle, it is the same procedure as for cabling for the lower transmission classes EA, E, and D or Cat. 6A and lower.
Nevertheless, the bar is much higher with Cat. 8.1 or Class I. The reason is the admissible transmission frequency. It increases fourfold in comparison with the highest frequency that was possible with Class EA cabling. The specifications for Cat. 8.1 or Class I permit a phenomenal 2 GHz. The advantage: This can increase data transmission on short links up to 40 Gigabit Ethernet.
It depends on the measuring equipment
However, the 2 GHz is considered to be an extreme value that can push today’s measuring instruments and measuring methods to their limits. The signal-to-noise ratio plays a more decisive role than ever before. Testing plugs, testing modules, and patch cords can have a slight influence on the sensitive signals. The behavior of testing plugs available on the market varies. This can affect the quality of the measurements.
This is why installers should not take the measurements for formal acceptance lightly in a Cat. 8.1 installation. When they test the cabling, they should be particularly careful.
R&M defines underlying conditions
R&M is familiar with the situation and thus specifies its special standards. Anyone installing and verifying the Cat. 8.1 cabling system from R&M should consider the following two points:
- R&M is initially only accepting channel measurements for tests of Class I cabling in which special patch cords are used.
- The patch cord connectors have to be approved by R&M.
This is the only way the variation of the measured values can be reduced to an acceptable level and the performance of Class-I cabling be determined with any certainty. The Cat. 8.1 cabling system from R&M certainly proves its quality. In 2019, R&M was one of the first manufacturers to introduce a complete Cat. 8.1 cabling system. Standard-compliant permanent links can be created with it per ISO/IEC 11801, Class I, and ANSI/TIA 568.2-D, category 8.
R&M also recommends always verifying the installation twice – once for Cat. 8.1 and once for Cat. 6A. This is how installers can ensure that the cabling is backward compatible. That makes customers happy, too, as they can use their Cat. 6A equipment even longer. And they already have cabling in the building today, with which they can later migrate to 40 Gigabit Ethernet without any additional installation work.