IEEE Announces Amendment To PoE Standard

September 13, 2009 by Jeff Shepard

The Institute of Electrical and Electronics Engineers, Inc. (IEEE) has approved a new amendment to the IEEE 802.3™ standard which offers improved power-management features and increases the amount of power available to wireless systems.

The new amendment is known by the full name of IEEE 802.3at, "Standard for Information Technology – Telecommunications and Information Exchange Between Systems – Local and Metropolitan Area Networks – Specific Requirements Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications – Amendment: Data Terminal Equipment (DTE) Power Via the Media Dependent Interface (MDI) Enhancements."

"IEEE 802.3at uses the Link Layer Discover Protocol (LLPD) from IEEE Std 802.1AB, which allows dynamic power allocation and negotiation down to 1/10th of a Watt, and associated technology including Type, Length, Values (TLVs) from IEEE 802.3bc™, which was also recently approved" said Mike McCormack, Chair of the IEEE P802.3at Task Force. "This will allow equipment manufactures to manage their power supply costs and efficiencies at levels not possible with previous standards, and to cut their costs in the process.

"In addition," said McCormack, "we have increased available power up to 25W. This will allow Power over Ethernet (PoE) to address applications such as high power Wireless APs, gimbal mounted cameras, and even some netbooks, as well as newer emerging applications."

The new standard is fully compatible with IEEE Std 802.3. "The improvements made in IEEE 802.3at are all fully compatible with any device built to the 802.3-2005 standard," said McCormack.

IEEE 802.3at was developed by the IEEE 802.3 Ethernet Working Group of the IEEE Computer Society’s IEEE 802 Local and Metropolitan Area Networks Committee. Paul Nikolich, Chair of IEEE 802, said, "I congratulate the IEEE 802.3 Working Group and the IEEE P802.3at Task Force on the success of this project. It is yet another example of the industry coming together in IEEE 802 and after long hard debate, reaching consensus for the benefit of all the stakeholders."