1 July 2005 Power over ethernet Juicing the data wire and
cooking with Ethernet. In the past, it has taken 10 years or
longer for enterprise-based Ethernet technologies to be adapted
for use in industrial applications. Power over Ethernet (PoE),
because of its tremendous advantages, should take considerably
less time. The PoE standard, IEEE 802.3af, adopted in June 2003,
allows users to power devices over Ethernet cabling. It
originally came about to support wireless technology in areas
where the cost of providing or the physical impossibility of
deploying electrical wiring limited its deployment potential. As
such, PoE has contributed to wireless market growth because it
simplifies the RF survey task: Access points can easily relocate
because the requirement of locally accessible AC power does not
exist. PoE will have important repercussions for industrial
applications. The simplicity of combining signal and power in
one Ethernet cable connection will contribute to the already-
rapid transition to Ethernet-ba