BROADBAND POWERING

摘要

With the recent ratification of the IEEE 802.3af Power-over-Ethernet (PoE) specification, manufacturers of devices, such as Internet Protocol (IP) phones, WLAN access points and security cameras are rushing to introduce new products that are compliant with the IEEE standard and compatible with PoE-enabled Ethernet switches that are being introduced simultaneously. Power-over-Ethernet enables wireless access points and other devices to be powered directly over the Ethernet cable instead of by a local ac-dc power source. Up to 13W of power is available with PoE. Eliminating "wall wart" power supplies in favor of PoE input provides a-manufacturing cost reduction to the access point manufacturer, as well as a substantial installation cost reduction to the end customer since ac power lines do not need to be routed and installed at remote access points. PoE also provides added flexibility to wireless networks as access points no longer need to be located near ac power sources; access points can be placed for optimal coverage. Remote management capability can also be introduced with PoE so access points can be powered up/down and reset from the remote host.