Perimeter Security - What is it Good For?
Absolutely Nothing, If Done Wrong
Webster describes perimeter as, “the boundary or circumference of a figure having two dimension; the sum of all sides of the boundary. Webster goes on to describe security as”…freedom from danger or risk.” So when we put them together our most common definition of perimeter security goes something like this, “an identifiable boundary to provide safety from threats”.
We take that a step further in our definition: A boundary comprised of several different “layers” of defense, with each layer providing an opportunity to deter, delay and detect unwanted activity.
Most people think you have to have a fence in order to establish that boundary or perimeter and once you’ve done that, the fence will act as a deterrent and stop the threat. Both assumptions are wrong. You don’t need a fence to establish the perimeter. You just need to identify it in some way to let people know, “Hey, this is my space. If you want to come in here, then go down there and let me check out who you are”. Good folks will follow the rules and go down to the entry control or access point. The bad guy will climb over the fence in about 4 seconds or less, so not much deterrent here. So in reality the fence doesn’t act as a deterrent, it acts as a method of identifying good and bad intentions.
Therefore, the perimeter is merely a line of demarcation that says, if you’re over there we don’t care what you do but if you come over here, we want to know who you are, so go down there where we can check you out. Now, many of you will disagree with that. You will say, “No, the fence keeps the bad guys from doing bad things because they have to climb over it and they don’t want to get caught”. Exactly! But, the fence doesn’t deter them, it makes it so that if they climb over it we will detect this bad behavior and can possibly catch them. After all, the good guys will follow the rules and go down to where there is an opening in the fence.
This opening is usually in the form of an access or entry control point (ACP/ECP) of some sort, manned or manned. The ECP is where we check to see if the person trying to enter is allowed. There are many ways to do that but we’ll have to discuss that in a future article. For the time being let’s concentrate on perimeter security excluding its access control mechanics. There are three distinct purposes for establishing a perimeter.
We already established that, first, it delineates the property line that we care about (deter). Second, it may slow (delay) the bad guys as they approach with the idea that if we can delay them we may be able to spot their bad behavior. Which leads us directly into point three – it serves as an early warning systems (detect). It immediately allows us to determine ill-intent. Think about it. If the person climbing the fence wasn’t trying to circumvent the access control point then why climb over the fence. Why not, go down the ECP, show or use your authorized credentials and enter. Another way to think away it is, if a person were to break through a wall, you would think this behavior bizarre and want to check them out.
Which brings me to my next point; there are actually four perimeters or layers of defense and each provides an opportunity for us to design against our threats. Threats come in all shapes and sizes, but we usually are most concerned with vehicle or pedestrian threats. In pretty short order I can come up with about 40 natural and about 20 or so manmade threats. For the purpose of this article we’ll concentrate on vehicles and people.
Perimeter Design Considerations
- Visibility – what do people see - both good and bad? Consider proximity to your neighbors.
- Demographics/Statistics – crime rates, terrorist activity, first responder locations and emergency access
- Landscape and Environmental Conditions - Type of terrain and extreme weather
- Power Requirements - availability, if electronics are used to augment passive barriers
- Accessibility – whether by foot or vehicle, during normal and emergency operations.
- Physical barriers (most common) – fencing or vehicle barriers, landscaping
- Intrusion Detection/Access Control – quickly becoming the norm
- Response Forces – without them the other components are useless. Forces MUST BE well-trained, well-equipped and regularly drilled and exercised.
- If we build a fence high enough, we’ll be okay
- Assume the property boundary to be the external perimeter that requires the most robust system
- Making it look substantial – fortress like will deter everybody and all threats
- Putting barbed or concertina or razor wire on top will deter the bad guy
- Putting CCTV to capture activity without having response force capabilities
- Forgetting about moving vehicle threats (ask the security staff at the Brussels airport about this one. Had they installed cable-reinforcing to the fencing the diamond thieves would not have been able to cut the fence and drive up to the plane unnoticed.)
- Lighting portions of the perimeter that cannot be patrolled by security forces.
- Non-aggressive methods
- Landscaping and Designing Crime Out strategies
- Arial surveillance
- Balloons. This might be the most promising since they can stay airborne for very long periods of time. One advantage is they can be placed high enough to see three of the layers of defense.
- Drones. There are several companies out there that already have off-the-shelf products available. Once manufacturers are able to overcome the current short battery life cycle and extend them to 10-12 hours or longer and add analytics this will become a great tool.
- Robotics (mobile, semi-fixed or stationary)
- Mobile – with the advent of self- driven or remotely controlled vehicles I don’t think it will be too long before we see a company promoting a self-driving security patrol vehicle; equipped with sensors, camera systems and audible/visual capabilities
- Semi-fixed – these systems are attached to or immediately adjacent to a boundary line and can patrol randomly or in a sequential order (not advised). They can be equipped with sensors, CCTV cameras, spotlights and speakers.
- Stationary – these systems already exist. There are many systems out there that have CCTV fields of view of perimeters with video analytics, combined with sensors, DVRs, etc. Really the sky's the limit based on budget.
Don’t fall into the trap of thinking that the property boundary is your only perimeter and therefore, it’s the only one you protect. Use every layer of defense to deter, delay, detect or defend a would-be aggressor. Remember, it won’t happen on its own; you have to design your security system to be integrated because if it’s not – it’s worth absolutely nothing.
For more information about perimeter security see our article in Security Middle East magazine Jul/Aug issue
or send an email to firstname.lastname@example.org.