The Power of PoE
Cost-saving technology takes hold in security industry
- By Carla Saavedra
- Jun 01, 2009
Alexander Graham Bell may have invented the telephone more than 100 years ago,
but the device remains the basis for many technological innovations. Power over
Ethernet is the latest technology based on Graham Bell’s “vocal telegraph,” and
despite some hesitancy in the security industry, it is quickly becoming a popular way
to save space, money and energy.
VoIP phones first necessitated the use of
PoE because, unlike traditional copper wire
telephone systems, they require a separate
external power supply while data is transmitted
through an Ethernet cable. To solve
the problem, manufacturers began sending
power through the cables’ unused wire
pairs, eliminating the need for a wall jack.
They then realized that PoE could be used
to power other devices as well.
“The thought was, it doesn’t just have
to power IP phones … it could be used to
power wireless access points for wireless
LANs,” said Bob Beliles, vice president of
enterprise business development at Hirsch
Electronics. “[PoE] could be used to
power cameras, and it could be used to
power other network switches that might
be smaller and more remotely located.”
In 2003, IEEE standardized PoE requirements
with the release of 802.3af, and the
number of PoE products grew exponentially.
“With that standard in mind, everybody
could build edge devices that consumed
the power,” Beliles said. “Network
switch vendors could build the circuitry
into their network switches to supply
power to those edge devices.”
Lower Installation Costs
One of the major advantages that PoE
brought to the security market was the
freedom to install devices virtually anywhere.
Because the device is powered
through the same Cat-5 data cable, companies
no longer needed to build a wall
jack or power source near the device, lowering
installation costs up to 30 percent.
“There are actually two aspects to real
savings: power infrastructure that you do
not have to build because you’re getting
that with the IT infrastructure, and the
number of terminations that an installer
typically has to make,” said Andy Bulkley,
product manager of access hardware for
GE Security. In a traditionally powered installation,
Bulkley said, an electrician
would terminate the wiring at a junction
box near the door and run the proprietary
wiring back to a central control center,
typically an electrical closet, where it
would terminate again. “You’re cutting out
a good chunk of labor by only having to
terminate once.”
Since many businesses have switched
to VoIP phones to cut costs, they already
have the infrastructure in place to power
PoE devices such as IP cameras. Another
benefit to using the same IT infrastructure
is that most switches are backed up by a
UPS system, allowing them to remain on
during a power failure.
PoE-powered access controllers put intelligence
at the edge of a network, which
is important when a PoE cable fails.
“In a traditional configuration, your
controller might be controlling eight or 16
doors, and if it fails, you have a failure of
all the doors, which could significantly
impact security,” Bulkley said, adding that
if a PoE device fails, it is generally isolated
to that location. He said airports have
found the technology useful because of
specifications requiring them to isolate
power failures.
Space Saver
The consolidation of wiring also frees up
space in data closets. Charlie Howell, owner
and principal consultant of Security Concepts
and Planning, said PoE has helped resolve
some challenges he’s had with installations
involving small teledata closets.
“We had a location where we had a network
drop and didn’t have any power supply
or any room to put a power supply inside
this little bitty telephone box,” Howell
said. “So instead of mounting a power
supply outside, we just ran the cable from
the camera straight to the switch.”
Going Green
Not only does PoE reduce installation
costs, but it reduces energy costs as well.
As part of the standard, IEEE requires that
a resistor be put in place that would only
let PoE power a PoE-enabled device to
prevent overheating. This section of the
standard is especially important because
PoE cables can only deliver about 13 watts
of power to a device. The resistor also lets
the power-sourcing equipment and network
switches power more devices because
it allows the PoE cable to deliver
only the amount of wattage needed.
“The circuitry in these systems has
evolved over time such that if you only
need 7 watts, rather than allocating a full
13 watts just to one connection, the power
source will only send you 7 watts, and
then it will reallocate the other 6 watts to
something else,” Beliles said. Some of the
more sophisticated PoE devices not only
negotiate how much power is needed but
can even signal the power device when it
needs more or less wattage.
Resistance In The Industry
Despite the many advantages of using
PoE-powered devices, some resistance remains
in the security industry. Many physical
security personnel, especially in government
sectors, are reluctant to renounce
the battery-backup system on the power
redundancy to a camera -- a moot point if
the network switch has a UPS.
The second reason is the reluctance of
some security directors to transfer maintenance
and control to the IT side. “[Physical
security] guys are used to having components
that they control and maintain,
and they just want to blend the IT infrastructure
into security,” Howell said, explaining
that three of the last five government
facilities he’s worked with were
averse to using PoE because “they didn’t
want to go to the IT guy in troubleshooting
a camera down.”
Facilities that already have an existing
infrastructure that traditionally powers all
of their security devices will have less of
an incentive to incorporate PoE into their
systems. “However, there are still some
benefits in being able to more easily monitor
the systems and having them battery
backed-up,” Beliles said.
Of course, the biggest bone of contention
for facilities managers may be the
amount of wattage that is allowed to be
transmitted through PoE cables. Although
13 watts can power most interior cameras
and switches, it cannot power exterior
cameras, which often have more complex
features such as motorized pan/tilt capabilities.
Most strikes and access control
products also require more power.
The good news is that IEEE is expected
to come out with a new standard --
802.3at or PoEPlus -- sometime this fall
that will increase the wattage run through
PoE cables to 24 watts.
Although the wattage increase willexpand the number of security devices
that can be powered with PoE, it is yet
to be seen if it will eliminate reluctance
on the physical security side. Howell
said for most physical security managers,
the decision to switch to PoE
will be more of a mental shift than a
technological one.
“[The number of facilities switching to
PoE] is going to be a hard thing to measure,
but it’s possible that it could shift,
but I think it’s going to be an industry
shift -- more than it will be that specific
technology,” Howell said.
A More Flexible Approach
Rather than wait for the new IEEE
standard, some companies have released
security equipment that uses less wattage.
Canon, for example, developed a new
processor that consumes less power.
“A lot of companies are buying off-theshelf
equipment and cannot take the
power consumption down, so that they
need to use more than 13 watts,” said Ricardo
Chen, senior manager of marketing
planning and technical marketing at
Canon USA.
Recently, the company released a minidome
camera and a PTZ high zoom camera
with a 45x optical zoom that run on
less than 13 watts of power. Chen equates
the argument of needing higher wattage in
PoE cables to run PTZ cameras to the arguments
people made for increasing a
home’s voltage when washing machines
were introduced.
“Somebody went out there and said,
‘We need to increase the voltage in people’s
homes, so the washing machines can
work.’” Chen said. “But what manufacturers
said was ‘Every single household has110 volts of electricity. Let’s create a system
that is more efficient’.”
Other companies have produced products
that are both PoE and 24-volt DC-enabled.
GE Security’s DirecDoor, an access
control solution, runs on both PoE and 24-
volt power. The company supplies a power
budget worksheet to installers that helps
determine whether they can use PoE.
An Uncertain Transition
Transitioning facilities to PoE is sometimes
a two-step approach. Because analog
cameras are still popular among security
personnel, Howell said he first tries to
shift managers into using IP cameras before
shifting to PoE.
Managers can then transition a littler
easier to PoE because they already have
PoE-enabled IP cameras.
“But in order for them to do that, the
video manufacturers’ heads of software
have to make sure that IP cameras are
not locked in to just doing a coax or
DVR or to an encoder,” Howell said.
“They have to ensure [security
managers] can plug in the IP camera
anywhere on their security network.”
Despite its slow start, PoE will continue
to proliferate the security industry.
Bulkley said the newness of the technology
has made the adoption curve a little
longer, but sales of his company’s PoE device
keep going up every quarter. Like
Howell, Bulkley said cameras may be the
key to getting people to adopt the technology
more quickly.
“I think as people get used to running
cameras on PoE, that adoption curve will
probably shorten because they will start to
see the advantages and cost savings [of
PoE]. And they’ll start saying, ‘Hey I can
do this elsewhere, too,’” he said.
This article originally appeared in the June 2009 issue of Network-Centric Security.
About the Author
Carla Saavedra is a contributing writer for Network-Centric Security magazine.