ITU-T Recommendations

Short distance single-pair Ethernet (SPE) is well established in the automotive industry. The evolved 10 Mbit/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.
Deployment of 10 Mbit/s, 1 km SPE is still in its early stages at the time this Supplement was drafted, and field data is minimal.
Supplement 25 to the K-series Recommendations is necessarily predictive on resistibility requirements. Once 10 Mbit/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-series Recommendations.
Certain clauses are still under study.