IEEE Committee Further Defines Standards for High-Power PoE Equipment

January 25, 2007 by Jeff Shepard

The latest specifications defined by the IEEE802.3at task force at its most recent meeting on January 17, 2007, have been released. Two significant motions were passed at the meeting; first, preliminary cable ratings have been provided by the Cable Liaison TR42.7 Committee allowing 30W at a powered device (PD) for 2-pair and 60W at a powered device for 4-pair for cable systems at 45°C, with a maximum recommended installation limit of 5kW per cable bundle; second, classification and timings have been defined, so that a mechanism can identify ".at" and allows the PD to identify that it has a high-power ".at" source.

Values are still open to change and adjustment, and the standard is still a year away from ratification, but it is now possible to build hardware that meets these requirements with a high degree of confidence that they will be compliant to the standard. When implemented as a standard, IEEE 802.3at (PoEPlus) will allow at least 30W of power and potentially up to 60W. Phihong has already developed many products that deliver high-power PoE, but most customers would prefer a common industry standard for all devices on the market.

Applications that will benefit from the increased IEEE802.3at classifications and voltage include wireless multi-radio access points, Pan Tilt Zoom security cameras, IP phones with streaming video displays, computer workstations and LCD display panels. Other emerging applications, including emergency lighting, security system sensors and even medical monitoring, will greatly benefit from combining data and centralized backup power.