The perimeter security requirements for critical sites are changing. No longer are a chain-link fences considered adequate for all critical applications. Sophisticated intruders and saboteurs created the need for much more formidable fences that can intelligently detect intruders. Further, there is a desire to integrate the perimeter security components into a complete solution that incorporates all aspects of the customer’s security requirements. Based on this trend, Fiber SenSys, Inc. (FSI) performance tested our Fiber Defender^® sensor with the Ameristar Impasse II fence platform, one of the leading high security fences in the United States.