Power over Ethernet or POE as it is referred to, has been
around for a number of years in various versions. POE is designed to run power
over a single category 5/6 cable at the time data in being sent over the same
cable up to 100 meters in length.
Originally, the IEEE802.3af standard was adopted in 2003. At
15.4 watts, this technology was primarily used to power IP telephones, wireless
access points and stationary IP security cameras. It was quickly determined
that more power was needed and the IEEE802.3at standard was adopted in 2009.
The 802.3at standard provided up to 34.2 watts for newer categories of POE
devices such as video IP phones, multi-band wireless access points and IP
security cameras that utilized pan, tilt and zoom features.
Again, newer technology is driving power needed for POE
devices even further. There are a number of newer standards being proposed for
a higher powered version of POE. IEEE802.3bt is one that will provide 100 watts
of power. Also a new standard that has recently been ratified that is used in
the audio / video world referred to as HDbaseT-2.0 provides 100 watts of power,
and supports 4K video Dolby 7.1 audio, 100 mbs Ethernet, USB2.0 and 2 way IR
controls. HDBaseT-2 still uses one cable but a cat6a shielded is recommended.
As in a number of technologies in the data world evolve
unintended consequences happen. One issue with the higher powered POE and
HDbaseT-2.0 cables that are deployed is heat. With 100 watts of power, the
cable can produce a bit of heat. Where this can become an issue in when a
number of the cables are bundled in a duct heat can become an issue.
Several manufactures are addressing the heat issue by
developing cable to handle the power and heat.
Here are several links about this subject:
Cat 6A Cabling SystemMeets 100-Watt Standard for Power Over Ethernet
Heating Effects for Remote Power Delivery Over Bundled Power Delivery Over Bundled Cables
CAT-5 Cable Bundle Heating Experiment