TAMPER-PROOF
A good perimeter and intrusion detection system should be designed with tampering prevention in mind. Without appropriate tampering detection, the perimeter and intrusion detection system could be at risk for malfunctions. Some basic tampering detection include: mechanical tamper contact, anti-masking and anti-blocking detection, encryption, discrimination detection, sporadic cut alarms, mechanical and electronic adjustment detection.
The first level of protection is a housing tamper, which triggers an alarm when the cover of a sensor or control panel is opened, Joosen said. “A second level of protection, which is required in public and high risk environments, is a pry-off tamper which is triggered when the device — control panel, keypad or sensor — is removed from the wall.”
“A micro-switch should be in place to detect removal of the sensor cover and monitor sensor, and communication cables to detect cutting or short-circuiting,” Dewar said. In the case of a microwave volumetric sensor, it has a built-in fraud protection; the system will monitor the signal received at the receiver unit and trigger an alarm if the signal level falls below a set threshold or a jamming signal is detected.
Cable sensors are by nature sensitive to detect tampering and the circuitry enclosure is protected by security hardware and trip switches, Curtiss said. “The more sophisticated systems employ digital signal processing to detect network ‘spoofing' attempts.” Periodic maintenance should also include checking up on the tamper-proof condition for the system to deliver optimal performance.
PRICE VERSUS PERFORMANCE
The maxim “You get what you pay for” holds true in perimeter and intrusion detection procurement. Budget offerings typically sacrifice features and functionality, said David Smith, CEO of Optellios. “ Feature s such a s int rus i on pinpointing, cut immunity and multiple simultaneous intrusion detction are not seen on low-budget offerings.”
Security is very much like insurance policy — how one proves the ROI; however, the risk of crime, vandalism and loss of production should be considered, Dewar said. “Once the investment is done, the comparison is between low-cost and high-end solutions. Here, the customer will feel the difference through: integration TCO, documentation level, maintenance by the system integrator, ease of recalibrating the system and more. A well-maintained and calibrated system would last decades.”
Leaving cost and technical considerations aside, external site factors such as landscape (flat or hilly) and climate (rainy, dry or harsh) influence the performance of any product. For virtual fencing systems, such as radar or infrared beams, weather and climate conditions do not cause interference. However, devices need to be carefully placed and aligned so that the signals are sent and received accurately, meaning that precise engineering of products is a must.
More importantly, the quality of the installation, setup and maintenance could affect product performance. For instance, a site that includes an open area would be well-served with a buried cable system, which provides a wide detection zone that is immune to most sources of environmental nuisance alarms and is difficult to defeat since it is covert, Dewar explained. “For sites without such a clear-zone, a fence-mounted sensor with a continuous sensor cable can be used to detect fence vibrations and a digital processing system to analyze the vibration patterns to differentiate real intrusion attempts from nuisance alarms. If there is no clear zone or a pre-existing fence, a barrier sensor such as a taut-wire system is an option since it provides the deterrence and delay aspects of a fence, along with integrated sensors to detect an intrusion.”
“The No. 1 thing that can be done is to make sure that the end user is getting the right sensor for the application,” Dewar suggested. “As of yet, there is no one sensor that works well in all environments. For any given infrastructure site, the optimal physical intrusion detection system will depend on the specific site conditions.”