All the Hype
Finding the best way to design a layered security solution
- By Paul Shkedy
- Oct 01, 2017
Alongside the hype in the media about the border wall,
this might be a good time for commercial and industrial
companies to take a closer look at their own borders.
Threat levels are increasing due to rising crime,
civil activism and even cyber threats and it is more
important than ever to push the line of defense all the way to the
When addressing perimeter security, it is best to try and design
a layered system since there is no single technology or solution that
would fit every application. The layers and technology should be selected
based on the level of detection and identification that is required;
as well as the terrain and environment it will operate in, which
is ultimately determined by the value of the information or product
that is being protected. It would be an overkill to implement a multilevel
intrusion detection system with thermal cameras and a fiber
optic intrusion detection system on an anti-cut & climb fence that is
protecting a dog run.
When designing a perimeter security application it is important to
consider the “5-D” rule, Deter, Detect, Delay, Deny and Defend. Just
like in the example above, the D’s must match the objective and level
of threat. Although each layer has a specific goal it is important to
have a way of connecting them together to form a unified system that
provides situational awareness. Let’s look at each of these elements.
Begin with Deter
The dictionary definition of deter is: to discourage (someone) from
doing something, typically by instilling doubt or fear of the consequences.
This is the area that needs the most attention in my opinion
as it differentiates the intruder’s motivation. For the most part theft
is a crime of opportunity. The easier it is to reach objects of value
the more prone they are to be taken. Have you ever noticed how junk
yards have very intimidating fences built from flat steel panels with
barbed wire spanning the top and most likely a vicious dog inside the
property? This is a very intentional and effective method of deterring
opportunistic criminals from attempting to enter the yard. Only
those with a clear objective and intent would attempt entry.
There is a delicate balance between cost, aesthetics and deterrent
capabilities that must be considered when designing a perimeter system.
A perimeter with minimal deterrence capability will require a
greater investment in the other layers.
Before we get into the technologies, we need to first understand
the purpose of a wall or intrusion detection system.
The main purpose is to deter entry, however in this modern age
of information we would expect it to do more, at bare minimum, it
should give us additional situational awareness. After all without
knowing how many attempts it thwarted, we might feel that it was
a waste of resources and more importantly we may never know how many intruders succeeded.
What elements would be useful in deterrence?
A physical barrier is the basis of a deterrent system. The design
and material choices will determine the effectiveness. Understanding
the delicate balance between aesthetics and function is what makes
these choices very difficult. Very few corporate or industrial facilities
want to resemble a prison however there are ways of achieving
a balance between the look and the perceived/ actual effort it would
require to penetrate the perimeter.
Lighting is as important as the physical barrier because it intimidates
the intruder especially if it is well designed and strategically
placed. Motion activated lighting is also very effective because of the
surprise reaction and perceived detection. These can easily be used as
an early warning sensor and delay medium.
It has been shown that the strategic placement of warning signs,
is a significant psychological deterrent against crimes of opportunity,
signs are used very effectively in the residential security market and
should not be ignored in the commercial space. The idea behind using
signs is to encourage the would-be intruder to reconsider entry by
magnifying the possibility of apprehension. Other deterrents include
landscaping and plant selections as well as animals and guards.
Even the best deterrent perimeter will require a detection system
that is capable of verifying the perimeter’s effectiveness. Just because
there was no evidence of breaches, it doesn’t necessarily mean there
weren’t any breaches and this is the reason why there should be a
routine review of its effectiveness and adjustments made accordingly.
A Plan to Detect
Effective detection systems should do more than just detect intrusion
attempts; they should also provide greater insight into the nature of
the intent. By designing the system to be able to identify and classify
the method, force and agility of the attack, we can better understand
the nature of the threat and subsequently prepare a better defense.
For example: in a very high security application, there may be
an area outside the perimeter fence that is designated as a deterrent
zone, discouraging advancement towards the perimeter. By using radar
or thermal imaging with analytics, the detection system would
then trigger an alert when an intruder entered the deterrent zone and
track targets as they advance through the deterrent zone, alarming
when they enter the area adjacent to the fence. This early warning
of an imminent breach would provide additional time to engage the
intruder. With a lower level of security, the requirement would only
be to detect the attempt at the fence or just inside the perimeter.
When determining the detection method, a significant amount of
consideration must be given to the environmental factors around the
detection area like: wildlife, visibility and natural camouflage. These
can interfere with detection capabilities or cause nuisance alarms. It is
always advisable to build a tiered detection system using at least two
different technologies thus reducing the possibility of unconfirmed
false alarms. An example of this would be using thermal cameras
together with a fence intrusion detection system to determine if the
fence alarm was caused by an animal or a real intruder.
Since there is such a vast amount of technologies that can be used
to detect or confirm detection of intruders, here is a list of technologies
that can be used for perimeter detection.
- Fiber optic and RF fence mounted cable and sensors
- Electric fence
- In ground sensors
- CCTV – traditional and thermal combined with analytics
- Ground and thermal radar
- Seismic acoustics
- Microwave and infrared sensors
- Laser sensors
Deny By Being Proactive
Up to now we have been passive in the process, relying upon the deterrent
to do its job, but since the detection system has been triggered,
we need to be proactive in preventing intrusion by denying entry. Denial
of entry must be done early and with the intention of dissuading
further attempts to gain entry. One of the most effective methods
beside physical confrontation is through voice commands.
The use of remote loud speakers or long range acoustic hailers is
very effective at getting the attention of the intruder as well as bringing
attention to the area. By issuing a stern warning that conveys
authority and strength of intelligence, the intruder is warned that
any advancement will be met with force, both perceived and physical.
This is the reason why the scripting of this message is paramount to
In some instances of very high security targets, the denial and
delay phases may occur outside the perimeter or inside a DMZ just
inside the perimeter.
The denial phase also triggers the delay protocols which would include
additional electronic and design tactics that would slow down
the advancement towards the target. It is important to design the delay
phase with three main goals.
- Delay the intruder from reaching the target.
- Direct the intruder to a safe engagement point for apprehension.
- Provide sufficient time for a response team to engage.
On the physical side an LRAD type system together with high
intensity strobes would be very effective at stopping the intruder from
further action due to the physiological effects on the human body.
Since these systems tend to stretch the budget, there are other methods
of delaying the advancement of the intruder towards their target.
By designing landscape obstacles in conjunction with lighting, audio
and sensors we could force the intruder into a funnel leading to
a safe area of interception. Drones are starting to play an increasing
role in both delay and identification of intruders. Their entry into the
market is slow due to FAA regulations and their investment in more
sophisticated autonomous drones.
Defend from an Intruder
Should the previous four layers fail to stop the intruder from advancing,
they will at least have slowed the advancement enough to allow
time to defend the target. Although defense is the least desirable and
most dangerous situation, with adequate planning some of the danger
can be mitigated because we now understand the full intention and
skill level of the intruder even though we may not know the target.
Perimeter intrusion detection is only one part of the total physical
security plan. Other components include access control, CCTV,
video management and storage, analytics, intrusion detection and
possibly a PSIM system. A comprehensive command and control
system would also include other building and automation systems
like HVAC, lighting, sprinkler and parking systems.
In order to design a comprehensive and effective security plan,
it is advisable to adopt a holistic approach that starts with a valid
vulnerability survey that examines every aspect of the facility, including
utilization, occupancy, physical and human targets as well as all
electrical and electronic systems and evaluates their effect on safety
and security. One factor that is often ignored is
the continued evaluation and adjustment even
after the system has been in place for some time.
Security is as dynamic as the environment.
This article originally appeared in the October 2017 issue of Security Today.