Power over Ethernet as of IEEE 802.3af limits the allowed power of an attached powered device (PD) to 13W.
Current enhancements call for higher power limits (up to 60Watts).
The new standard is named "IEEE 802.3 at" and is currently developed by the IEEE P802.3at DTE Power Enhancements Task Force. Currently, PoE uses two out of the four twisted pairs in a cable. IEEE802.3at now aims in using all four pairs in phantom technique to carry power and data on the same pairs (see also IEEE 802.3af for Gigabit Ethernet).
Besides the main goal of increased power limits, there is also a demand for smooth adjustments to the actually required power of the enpowered device. This level may change during sleep times etc. The standard is expected to be approved in 2007.

