Higher limits on Power over Ethernet (PoE) are coming closer. The IEEE PoE Plus Study Group has met twice since it was formed last November to develop ways to increase the maximum power that can be transmitted via IEEE 802.3af PoE from power-source equipment (PSE) to powered devices (PDs). Currently, 802.3.af limits that to approximately 13 W at the PD.
The group set a number of objectives at its first plenary session in January. It determined that the PoE Plus target infrastructure will be ISO/IEC 11801-1995 Class D or higher systems. It also said PoE Plus should not cause a safety issue for a legacy installations that conform to ISO/IEC60950. A vote set the minimum power level that PoE Plus would support at the PD at 30 W. But the group didn't determine if PoE Plus would be interoperable with 1G and 10GBaseT. Further discussion will be necessary.
Presentations rounded out the rest of the January meeting. Mike S. McCormack of 3Com explored cable-heating issues. Power Dsine's Daniel Feldman projected the market for PDs that require 30 to 40 W to reach 80 million units by 2008, or double to triple the size of the 13-W PoE market.
IEEE PoE Plus Study Groupwww.ieee802.org/3/poep_study/index.html