FiberPDS Fiber-Optic Alarmed-Carrier FAQs
FiberPDS extends electronic tamper monitoring to long communication routes, campus backbones and building-to-building infrastructure. The processor sends light pulses through a standard single-mode sensing fiber and analyzes changes in the backscattered light using distributed acoustic sensing. This allows the system to detect, classify and locate mechanical activity along the monitored route without field electronics or field power. For government PDS applications, the complete design remains subject to approval under the applicable security requirements.
What is FiberPDS?
FiberPDS is a distributed fiber-optic sensing system for monitoring conduits, pipes, raceways, cable trays and related communication infrastructure. It can support long-range alarmed-carrier PDS designs by reporting mechanical activity associated with attempted access and identifying where along the sensing fiber the event occurred.
How does the fiber become a sensor?
The processor transmits laser pulses into a standard single-mode fiber and measures changes in the naturally backscattered light. Vibration or acoustic energy coupled into the fiber changes that return signal. The system analyzes those changes to determine the position of the event along the fiber and compare the signal with configured detection classes.
How long a route can one FiberPDS processor monitor?
The system supports up to 100 km (62 miles) of total sensing-fiber length per processor. In a straight-line configuration, the maximum distance from the processor is typically up to 50 km (31 miles). The supported distance for a specific project depends on the topology, optical loss, connector and splice quality, and the selected architecture.
How accurately does FiberPDS locate an event?
FiberPDS provides spatial resolution of approximately 3 m (10 ft) along the sensing fiber under suitable design and installation conditions. Fiber distance is not automatically the same as physical map distance. During commissioning, the route must be mapped and must account for slack, service loops, splice enclosures, gate loops and other sections where fiber length differs from ground distance. Vidalert can then associate the measured fiber position with a physical route location or map coordinate.
Can FiberPDS use an existing fiber-optic cable or spare dark fiber?
Often, yes. FiberPDS can use an appropriate spare single-mode dark fiber in an existing cable or a new dedicated sensing cable. Availability alone does not make a fiber suitable. RBtec should review the route topology, cable construction, mechanical coupling, connector type, splice plan and OTDR test results before the sensing design is approved.
How is the sensing fiber installed on the carrier?
The sensing cable can be attached along the outside of a conduit, pipe or tray, or installed inside a suitable carrier. The installation must transfer the mechanical activity of interest into the fiber consistently. Loose, isolated or poorly coupled cable sections can reduce sensitivity, so installation details and representative field testing are important.
Is field power or active equipment required along the route?
No. The sensing fiber is passive, and the processor is installed at a secure endpoint. No powered sensing units are required along the monitored route, which reduces field infrastructure and maintenance requirements.
Does FiberPDS support a CNSSI No. 7003 alarmed-carrier design?
FiberPDS can provide the continuous tamper monitoring, fault supervision and alarm information needed as part of an alarmed-carrier PDS design under CNSSI No. 7003. The product is only one component of the solution. The complete route, carrier construction, access conditions, alarm annunciation, response time, test schedule, operating procedure and documentation must be reviewed and approved by the responsible Authorizing Official and cognizant security authority.
Where is FiberPDS typically used?
Typical applications include campus backbones, long carrier routes, approved building-to-building links, data-center interconnections and communication infrastructure that passes through areas of lesser classification or control. CNSSI No. 7003 does not permit an unencrypted PDS through an Uncontrolled Access Area, so approved encryption is required wherever that condition exists.
When should I use FiberPDS instead of ShortPDS?
ShortPDS uses copper sensor cable for short point-to-point runs and can monitor up to four independent 1,000 ft (300 m) zones from one processor. FiberPDS is intended for routes measured in kilometers or miles and provides distributed event location along the fiber. Many projects use both technologies for different portions of an approved end-to-end design.
Does FiberPDS affect traffic on the protected network?
When FiberPDS uses a dedicated sensing fiber or spare dark fiber, its optical signal remains separate from the traffic-carrying fibers. It does not connect to or alter the protected data stream. The sensing fiber and complete PDS architecture should still be included in the technical review and approval documentation for the project.
Can FiberPDS detect digging near a buried route?
Yes. When the cable is installed and coupled appropriately, the system can detect and classify vibration associated with excavation or digging near buried sections. Detection distance and classification performance vary with soil, burial depth, cable construction, equipment, background activity and system configuration. Site-specific testing is required to establish acceptance criteria.
How are alarms sent to the security operation center?
Vidalert displays the event type, measured fiber distance and mapped route location. Network integration can pass detailed event and location data to compatible security platforms. Dry-contact outputs can also report alarms to a standard panel, but a relay normally represents a configured zone and does not by itself carry precise distance or coordinate information. The required integration method should be defined during design.
What information does RBtec need to design a FiberPDS system?
Provide the route length and topology, origin and endpoint locations, carrier type, existing cable and dark-fiber availability, splice and connector details, OTDR results, buried and aboveground sections, service loops, alarm-monitoring location and required third-party integrations. RBtec can then develop the sensing architecture, mapping plan and bill of materials.
Still have questions?
Contact RBtec at +1 (301) 760-4016 with your route drawing and available fiber information. Our team can review the topology and recommend a FiberPDS architecture, commissioning plan and integration method.