Summary

Short distance single-pair Ethernet (SPE) is well established in the automotive industry. The evolved 10 Mb/s SPE, with up to 1 km or more of link length, is aimed at industrial, building and security applications. This relatively new Ethernet variant is still being standardized and a full set of preferred implementation components are not widely available. The first part of this Supplement gives an overview of the SPE system before proposing possible SPE surge protective device (SPD) test circuits.

The long distance between the SPE terminal equipment means that coupled transients can be significantly larger than those tested for in Recommendation ITU-T K.117. The transient levels are higher due to local earth potential rise differences and Ethernet link cable length. The SPE configuration combines the Ethernet signal and any powering voltage on the two SPE link conductors, making the separate measurement of signal and powering protection performance more complicated.

Field data on 10 Mb/s, 1 km SPE resistibility was minimal in 2020 due to lack of deployment. In 2021 there should be wider availability of support hardware such as cable, connectors and Ethernet PHY transceivers. Supplement 25 to the K-series Recommendations is necessarily predictive on resistibility requirements. Once 10 Mb/s, 1 km SPE is widely deployed and field data is available, resistibility requirements can be based on such data and incorporated in the appropriate K-Recommendations.

Certain clauses are still under study.