08/12/2011

Information of the Committee GUK 715.3 – November 2011

Data transmission with 40 Gbit/s over balanced copper cabling; the application of "Power-over-Ethernet plus (PoE+)"

Information by DKE/GUK 715.3 "Informationstechnische Verkabelung von Gebäudekomplexen", German National Mirror Committee to ISO/IEC JTC 1 /SC 25 WG 3 "Customer premises cabling" and CENELEC/TC 215 "Electrotechnical aspects of telecommunication equipment".

Data transmission with 40 Gbit/s over balanced copper cabling.


For data rates > 40 Gbit/s IEEE 802.3ba so far contains spezifications, which do support cabling links up to 7 m with 8- and 20-pair Twinax cables, respectively, or cabling links up to 100 m/150 m with 8- and 20-fibre OM3/OM4 optical fibre cables, respectively.

In order to take advantage of balanced copper cabling also for this application, the 51st meeting of ISO/IEC JTC 1/SC25 WG3 "Customer premises cabling" in Melbourne decided to initiate a specification for balanced 4 pair copper cabling with data rates of > 40 Gbit/s, which may be used for example in data centres.

To this end a project team has been established to demonstrate to the IEEE 802.3 working group the feasibility of cabling channels with components of Category 6A (500 MHz) through 7A (1000 MHz) in accordance with DIN EN 50173-1:2011-09 as well as to evaluate the potentials for further developments.

Information regarding the application of "Power-over-Ethernet plus (PoE+)"

Series DIN EN 50173 supports, among others, the applications "PoE" and "PoE+" on standards compliant generic cabling systems (see the tables of supported applcations in DIN EN 50173-1:2011-09, Annex F).

There is equipment being offered with additional functionality such as power supply, additional signal transmission, extenders for media technology, which offer higher voltages and currents than foreseen in specification IEEE 802.3at on "PoE+“. Parameters of these applications may significantly exceed the application range supported by DIN EN 50173 and may result in damage and constitute a safety hazard. As some of these products are being marketed as "PoE" or "PoE+" compliant, DKE/GUK 715.3 feels obliged to explicitely highlight this issue.

The standards mentioned can be obtained from Beuth Verlag.