Ask the Expert
- By Brad J. Wilson
- May 29, 2008
From border security and large
industrial workspaces to outdoor
arenas or military compounds,
perimeter security is the first line of
defense against outside threats. As technology
changes, so do advances in perimeter
security systems. How can you be sure
that your security integrator is keeping up
with the latest technology, and what “lowtech”
methods are still useful?
One of the most important aspects of
perimeter security is granting access to
approved persons only. Recently, this has
become increasingly important because
of the threat of terrorist attacks.
ISSUE: What are some easy-to-install,
low-tech perimeter security options?
SOLUTION: Security gates ensure that
only authorized and approved personnel
enter a facility. Depending on location,
these can be manned with armed guards
and use a barricade that is lifted upon visitor
approval. Bollards are sturdy physical
objects, such as Jersey barriers or concrete
blocks, that stop moving vehicles
from hitting a building directly. A large
effort has been made to improve the aesthetics
of these kinds of barriers, and they
are now decorated with plants and flowers
or designed to flow seamlessly into
the building structure.
If there is a serious threat of a vehicular
attack on a gated or a fenced area, specialized
security fencing is available that incorporates cabling to restrain a vehicle.
It is also wise to think about slowing
down vehicles before an impact.
Reducing a vehicle’s speed by 50 percent
can reduce the potential impact by nearly
four times. Discuss with your integrator
the possibility of integrating vehicle
access control and perimeter bollards into
your perimeter security plan.
ISSUE: What are some higher-tech
solutions in perimeter security?
SOLUTION: On the high-tech end, cameras
often have been the first solution for
keeping track of people entering and exiting
an area. But they also have problems.
The inability to detect movement has
meant that security guards traditionally
have been used to monitor a number of
cameras, looking for any unusual activity.
However, this is an inefficient method as
recent studies show guards viewing multiple
monitors are unable to stay focused for
more than 20 minutes.
Video analytics has been one solution
for detecting movement within a camera’s
field of view. The technology is able to
decipher between human and vehicle
movements, whether a person is in a
restricted area or even if a vehicle is traveling
too fast or in the wrong direction.
Unfortunately, video analytics has its own
pitfalls as it can be influenced by weather
changes such as wind gusts that lead to
false alarms triggered by apparent movement.
Video analytic solutions traverse a
wide range—from relatively simple to
highly sophisticated algorithms.
Some integrators also may recommend
the addition of pan-tilt-zoom (PTZ)
cameras. Traditional perimeter security
cameras have a wide angle, which takes
in a large field of view but is not helpful
in identifying smaller objects. PTZ cameras
will allow the user to get a closer
look at an object, helping to determine
whether it represents a real threat.
Intrusion detection sensors can be used to
trigger and direct the PTZ to a preset
zone position for verification and recording
of the alarm’s cause.
Speaking of intrusion detection sensors,
there is no “one-size-fits-all” technology
suitable for all perimeters. The
final choice of type and technology
depends on a number of factors as well as
the operation and objectives of the facility.
Perimeter security can employ both
high- and low-tech methods of protection,
depending on size, cost and logistics. Talk
to your integrator about options available
that are right for you.
READER QUESTION: We have a
number of small buildings surrounding
our main warehouse. All of them
are located within 50 yards of the
main facility. Although our most
expensive materials are kept in the
warehouse, these smaller buildings
also house valuable equipment. We
would like to extend our access control
system to include those five buildings.
Are there wireless systems that
can work for us? We are located in the
upper Midwest, where the winters can
SOLUTION: Based on your question, I
assume that you currently have no connectivity
between these buildings. There
are several options to extend your access
control system. If you simply wish to
allow a single card to work in all buildings
and maintain an audit trail of who
accessed each area, a dial-up connection
may be the most cost-effective. Access
control systems can typically push badge
updates and retrieve transaction history
data on a regular basis via standard
PSTN lines. This is a low-cost solution
that works well in many circumstances.
Although more expensive, wireless
options may provide a better solution for
this application. A wireless network
could be deployed to connect the buildings
through a WiFi network. The access
control system could then connect panels
via TCP/IP, thus having a constant connection
for real-time updates and system
integrity. Another big advantage to this
solution is that it allows you to use the
new WiFi network for other security and
Regarding the effects of harsh weather
in the Midwest, many card readers are
now manufactured to withstand extremely
harsh climates. These card readers are
sealed to prevent water and moisture
damage and have operating temperatures
of -30°F to 150°F.
This article originally appeared in the May 2008 issue of Security Today.