While direct burial or fence-secured systems are still labor intensive, some manufacturers have implemented systems which use standard fiber optic cable, dedicating limited numbers of fibers in the cable to the sensing function. This means that the same cable used for communications — voice, video or data — can also be employed for sensing, simply by allocating individual fiber strands in the cable to that purpose. This can significantly reduce the incremental cost of implementing the sensing function, or it may simply build in future capacity for communications if properly planned. Since unrepeated sensing/transmission distances of 100 km (67 miles) have been reported, the technology is applicable to supervising long stretches of rail bed, highways, utility lines and the like.
Also, if intrusion sensing is not the immediate objective, the same technology can supervise critical fiber optic communications infrastructure, providing early warning for an impending event. Further, the technology lends itself to wide area sensor communication networks, offering the promise of coupling in various types of physical sensors and audio discrimination.
Both of the technologies mentioned above have their preferred applications and, in some cases, may complement each other. It is both interesting and encouraging that, in the most challenging surveillance environments, excellent proven detection tools now exist to provide required levels of performance. These and other perimeter technologies will be on display at ISC-West, and I encourage readers to seek them out, witness a demonstration and challenge manufacturers to prove their capabilities. These technologies have enough promise that your discussions may even lead to new applications!
Ray Coulombe is Principal Consultant for Gilwell Technology Services, providing product and market-related strategic assistance to early stage companies in the physical security and transportation markets. Ray can be reached at firstname.lastname@example.org or through LinkedIn.