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 be brutal.

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 business applications.

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.