Perimeter Security


In this post we cover the following topics helping you to improve your perimeter security:


  • Factors for an intrusion to occur
  • Intrusion Prevention
  • Layered security
  • Layered Security Components
  • Rapidly deployable Perimeter Intrusion Detection System
  • The Five-Step Process to mitigate intrusion threats

Factors for an intrusion to occur


Crime requires three factors in order to occur. These factors are Inclination, Assets and Opportunity. The removal of one or more of the components will prevent the crime from occurring. 

To understand these factors better and  their role in crime prevention, let’s take a look at them individually



Inclination describes the motivation of an individual to commit a crime. Examples are: financial gain, revenge, jealousy, anger and hatred. 

Because inclination involves a person and their mental processes, it is the most difficult component to remove. Inclination exists in the realm of psychologists, sociologists and criminologists. There is little that a security or risk managers can do to influence it. 


This factor describes something to be gained by committing a crime. Assets are usually thought of as tangible objects such as a vehicle, power generator, solar panels, money. 

However they may be intangible or abstract objects.  People on the property might be an asset that comes under attack due to revenge, anger or hatred.

While it may be theoretically possible in some instances to remove assets to prevent crime, it is generally impractical or unrealistic. 


Opportunity describes the circumstances and conditions that permit a crime to occur. Every crime has its own unique set of opportunities, but two conditions are usually present: 

  • Access to the asset(s),
  • An apparent likelihood that the crime can be committed successfully with minimal risk to the perpetrator. 

Opportunity is the crime component that is most readily influenced by security measures. When developing security program, the first priorities should be the recognition of criminal opportunities followed immediately by the initiation of actions to remove those opportunities.

Lixodex perimeter intrusion detection

Sensors, dependent on the frequency of communicating have a battery life of 3 to 10 years (such as Lixodex).  This is due to advances in battery, processor power consumption and Low Power communication systems technology.  These systems include communication error correction and jamming detection.  Electronic counter measures such as jammer direction finding are optional.

Improve Perimeter Security through Intrusion Prevention

Most crimes occur because the criminal found the right opportunity to act. The criminal’s inclination and the victim’s asset came together at a time and place where the criminal felt they could successfully commit the crime with minimal risk of interference or apprehension. That is, the criminal found circumstances and conditions to be within their comfort zone. 

Your job when developing a security program is to create an environment that lowers the comfort level of potential criminals. Applying the three “D’s” of crime prevention helps do this. 


The goal of deterrence is the creation of an environment that is unattractive to criminals. 

Anything that increases the likelihood that a criminal’s actions will be observed and reacted upon by security personnel is a deterrent. 

In general, open, well lit, well used areas are less susceptible to crime. 

The visible presence of security measures and the use of access control devices and barriers are deterrents. 

A successful deterrence program makes the criminal hesitant to commit their crime in that environment. 

Effective deterrents place psychological and/or physical barriers in the criminal’s path and imply to them that they have no easy opportunity to successfully commit their crime. 


When a crime does occur, early detection greatly increases the odds that the criminal will be apprehended. 

Early detection can be accomplished by a variety of means such as perimeter intrusion detection.

Various electronic devices can be employed to detect criminal activity. These devices include sensor based alarm systems and closed circuit television. 

The presence of alert security personnel and reaction teams and electronic security devices sends a message to the potential criminal that their actions will be detected. 

This increased risk of apprehension reduces their level of comfort. As a result, opportunity is also reduced. 



In spite your best efforts, some criminals may not be put off by security measures and other deterrent efforts. In these instances, your next line of defence is to delay completion of the attack. 

The longer it takes a criminal to complete an attack, the greater the probability that they will be observed and apprehended. 

Barriers such as solid doors, good locks, fencing and other physical security measures are all devices that delay a criminal’s activities. 

The presence of delaying measures increases both the difficulty and risk associated with a criminal’s activities. Increased delay usually equates to decreased opportunity in the criminal mind. 


Response, which requires human involvement, covers procedures and actions for assessing the situation and responding to an intrusion. Note: Because absolute protection is impossible to achieve, a security program that does not also incorporate detection, delay and response is incomplete. To be effective, all three concepts must be elements of a cycle that work together continuously. 


How do you or your organisation recover from a criminal act. Recovery is your plan to continue business and operations as normally as possible following an incident. 


Re-evaluation is critical. You must constantly keep your security plan under review and keep re-visiting your original assessment and objectives. Has the situation changed, do you now face new threats and what must be done to ensure the security plan continues to meet your goals and objectives? 

ClearVU type mesh fencing

Sensors, dependent on the frequency of communicating have a battery life of 3 to 10 years (such as Lixodex).  This is due to advances in battery, processor power consumption and Low Power communication systems technology.  These systems include communication error correction and jamming detection.  Electronic counter measures such as jammer direction finding are optional.


Perimeter Security as part of Layered security 


Most businesses already know that having a fence is not enough of a deterrent to keep intruders out.  

In many cases fences are in themselves the target of criminals where the fence material is stolen and used in other applications such as building temporary dwellings.

The last ten years or more has seen the addition of electrical fences to add an additional layer to fences as a deterrent.

Common criminals have learned over time how to circumvent electrical fences by using all types of objects to isolate wires and to draw them apart to gain entry without electric shock or sounding a zoned alarm.

This might sound like a hopeless situation, but when we consider security in a layered approach one can combine systems that assist in deterring and detecting criminal intrusions into properties.


Layered Security Components

Let’s consider the different ways in which we can deter, detect and delay intrusions, lets see what is in the toolbox.  


Fences and Walls

Fences and walls, are a key component of a site’s external protection. They help protect a site by:

  • Delineating the boundary
  • Deterring intruders, the casual ones
  • Providing a delay to an intruder (against burrowing, penetrating or scaling) when used in conjunction with a Perimeter Intrusion Detection (PID) system or another means of detecting an incursion can be detected.
  • Acting as a host for barrier mounted perimeter intrusion detection sensors (PIDS)  (the two systems need to be compatible)
  • Acting as a barrier to vehicles if suitably enhanced with Hostile Vehicle Mitigation (HVM) measures
  • Enabling external view though fence line, or when required, provide cover from view.


Walls can also:

  • Prevent observation of the guard force, guard force patrol movements and assets within the site 

Fences and walls provide only limited delay against a determined or skilled attacker, but can also be vulnerable to attackers, with only limited skills and equipment, if they are not correctly designed and installed. 

Electric Fences

The primary function of an electrified fence is as a deterrent and detection system. Because of its nature of operation and physical appearance some regard it as a physical barrier. However, as a barrier, it is a good deterrent but offers little delay. As a detection system it can offer low false alarm rate and good detection performance against climbing and penetration attacks.

Electric fences and their circumvention by low skilled intruders have become common place.  Electric fences by themselves do not provide a high level of security.

Perimeter Intrusion Detection Systems


Fence alarms incorporate sensors that are attached to fence structures to pick up vibrations and generate a response. This response can turn on a warning siren, light up a fence section or surrounding field, activate video surveillance and more.  In the case of Lixodex sensors any authorised person can see the status of each sensor across the whole perimeter on Google Maps from a mobile phone or computer, and see exactly where a intrusion alarm has been raised.


Security video cameras Lixodex

CCTV Security Systems


CCTV or closed circuit television involves the surveillance of the property through exterior video cameras. An Intelligent Video Analysis is performed on the images of the cameras, and in parallel all the images are continuously recorded on a recording device. Additionally they are visualized by the vigilantes both on-site and remotely, so that they can anticipate an intruder.


Ground Radar


Ground Radar detects potential perpetrators moving in from land. Units are often placed remotely, may be fixed or mobile; solar, battery or electric powered, and installed to communicate through wired or wireless connections.


Microwave Sensors


Microwave sensors, also known as Radar, PF or Doppler sensors, detect walking, running or crawling human targets in an outdoor environment. These sensors generate an electromagnetic (RF) field between the transmitter and receiver, creating an invisible volumetric detection zone. When an intruder enters the detection zone, changes to the field are registered and an alarm occurs.


Security Gates & Operators


ASI Security has more than 21 years of experience installing security gates and operators for commercial and government clients. Whether you have a barrier gate, pedestrian gate, swing gate or vertical pivot gate, it is critical to have the right security gate opener installed and functioning properly to secure your facility.


Thermal Imaging


Thermal Imaging is often used in conjunction with radar to provide a detailed visual image of approaching people or objects, even in complete darkness.


Fiber optic detection systems

 It is used to detect presences by a fiber optic cable. It is suitable to protect fences and walls, and to cover large perimeter extensions.


Video Motion Detection


Video Motion Detection (VMD) may be installed as a stand-alone system or integrated into other detection systems to detect motion and capture the events. VMD is especially suitable for low-traffic areas as it detects moving objects (such as people or vehicles) within the predefined area, making it possible to automatically trigger an action.


Volumetric / Ground Sensors


Volumetric and Ground sensors generate an invisible detection field to detect intruders moving through it. Because the detection field is invisible, it is a fairly impenetrable security system. There are a variety of sensors which may be configured for multiple applications, including above- and below-ground sensors.


Microphone cable fence disturbance sensors


It is a perimeter protection system by cable that runs along the entire fence. When you try to climb or cut the wire, it becomes a real microphone that transmits the sound to the center.


Seismic sensors


These devices detect vibrations within their field of action and activate an alarm. They do not serve to detect an earthquake, but vibrations that can have several origins. A possible alert would be an attempted robbery by means of a hole in the wall to access a vault or against the use of thermal lances to pass through steel or concrete.


Active infrared systems 


These systems have no dead zones near to the transmitter/receiver units but can be particularly susceptible to the effects of fog causing false alarms. These systems are only to be installed over flat ground as undulations can create dead zones. The alignment of transmitters and receivers over long ranges can be difficult. Features are available for these systems which can reduce false alarms from small or fast-moving wildlife (such as requiring more than one beam to be broken, or beams to be broken for longer than a  defined period of time). These systems also typically require a hard-wired synchronisation cable between each pair of transmitters and receivers, preferably in underground ducting. 


Passive infrared (PIR) systems 


These systems are not recommended for use as the primary detection solution for outdoor environments as their poor immunity to changing temperatures results in either a very poor detection rate or a very high false alarm rate. PIR systems generally use two types of optics to gather the infrared energy from the scene: Fresnel lenses; or more expensive mirror optics which are more accurate for long range (~100 m) applications. A variety of coverage patterns exist, from short and wide detection zones to long and narrow zones. Careful positioning is required due to dead zones and sources of false alarms such as sunlight or other distant, hot objects. 


Laser scanner systems 


As with active infrared systems, laser scanner systems can be susceptible to the effects of rain and fog. These PIDS can often have the ability to define parameters such as minimum target size or beam break time in a software environment.

laser scanner system Lixodex

Rapidly deployable Perimeter Intrusion Detection System 

Rapidly deployable Perimeter Intrusion Detection Systems  have advanced drastically with the introduction of IOT (internet of things) technologies over the last several years.  The same sensors can now be deployed rapidly to do detection over a limited time, while they can also be installed on a permanent basis. 

Battery power, microprocessors used, as well as low power communication allows sensor live from three years to ten years depending on the settings applied and the battery used. 

It has become more practical to indicate the number of thousands of interactions a sensor can have over its life, as the number of sensor to base station interactions are more important.  

The main advantages include portability enabling use at different locations; and no requirement for permanent infrastructure in their use. 

Lixodex sensors can be used as permanent installations and as fast deployable systems that can be easily be redeployed according to situational requirements.

Rapid deployment Lixodex

Sensors, dependent on the frequency of communicating have a battery life of 3 to 10 years (such as Lixodex).  This is due to advances in battery, processor power consumption and Low Power communication systems technology.  These systems include communication error correction and jamming detection.  Electronic counter measures such as jammer direction finding are optional.


The Five-Step Process to beef up your Perimeter Security


In order to carry out a comprehensive assessment of what your facility needs, you have to understand the basic elements of security – what it is you are protecting and how vulnerable it is. You have to know where any threats might come from and what you can do to prevent them or mitigate them. You have to understand the principles of deterrence, detection, delay, response, recovery and re-evaluation. You need to be aware of all the options available to you. Armed with this knowledge you can develop and implement the most appropriate integrated physical security plan for your facility. 

When planning, there are two scenarios: if and when. The “if” scenario covers planning and procedures to prevent the likelihood of an incident. The “when” scenario covers planning and procedures after an incident and is mainly concerned with mitigation and recovery. 

Remember that the cost to mitigate and recover may be less than the cost to protect, so there always has to be a balance between protection and mitigation.

Step One

Your Model Secure Facility 

A model secure facility – the facility that in a perfect world, is able to maximize security without compromising business as usual.

It is important that you examine what would constitute a model secure facility for you. This is one which has identified its core functions, identified its critical assets, identified the threats and vulnerabilities and taken the appropriate measures to mitigate them.

When you come up with your model facility, you have a benchmark for comparison. 

Step Two

Gap Analysis: How Do You Compare With the Model Facility? 

The goal of physical security is to protect facilities and buildings and the assets they contain. The most important of these assets are, of course, the people who work in and visit the facility. The first things you need to find out are: 

  • The assets to be protected 
  • The threat to those assets 
  • The vulnerability of those assets 
  • Your priorities 

Develop answers to the following questions.

What Am I Protecting? 

The goal of security is to protect facilities and buildings and the assets contained inside. Various layers of security may be necessary in different parts of the campus and buildings depending on the assets located there. 

Who Are My Adversaries? 

It is important to identify and characterize the threat to these assets. This threat can come from within or outside. 

Internal threats include pilfering of office equipment or theft of classified information. Internal threats also include disgruntled employees who may sabotage equipment or attack other employees. 

External threats range from vandalism and break-ins to acts of terrorism. 

You need to know your adversaries and the various tactics they might use. 

You also need to know their motivations and capabilities. 

Where Am I Vulnerable? 

Until you discover your areas of vulnerability, you cannot develop the strategies needed to protect them. 

You must identify and characterize vulnerabilities – weaknesses – that would allow identified threats to be realized. 

A major problem for businesses in urban areas is the lack of a secure perimeter. 

Also, assess how you might be impacted by an incident at a nearby facility, such as a chemical spill, and what steps you would need to take to protect your property and people. 

By identifying your weaknesses you are able to develop solutions to eliminate them. 

What Are My Priorities? 

Risk assessment must take into account the effect on your business or operation if assets are destroyed or damaged. 

Part of that assessment is to rate the impact of the loss of those assets on a scale of low, medium or high. 

This will identify the critical assets that need maximum protection. 

How Do I Compare? 

Once you have established the above, you are in a position to do your Gap Analysis to identify what needs to be done to reduce risk, increase safety and provide the necessary physical security for your building and people. How do you compare to the model facility?

Step Three

Having identified your shortfalls, you must then consider and evaluate all available options to mitigate the threats. 

There is a vast array of external and internal systems and devices available. 

You must determine which are the best options and combinations for your particular circumstances. If you have questions, consult an independent security consultant rather than a vendor with a vested interest in selling you its product.

Step Four

Having identified assets, adversaries, threats, vulnerabilities and determined priorities and options, you are in a position to plan and strategize the security change process. 

This means developing a road map – you know where you are and have to plot how you are going to get where you need to be.

Step Five

Once your strategic plan has been approved, it must be implemented. This includes project management, bid contracting and vendor selection, quality assurance and quality control, and revising policy procedures. 

Integrated physical security planning is also an ongoing requirement. 

Re-analyze your current situation. Ask yourself what has changed and what new threats have emerged. 

By constantly tracking and monitoring your integrated physical security system you can close any gaps and introduce enhancements. 

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