Editing Protective distribution system (section)

=== Alarmed carrier ===
As an alternative to conducting human visual inspections, an alarmed carrier PDS may be constructed to automate the inspection process through electronic monitoring with an alarm system. In an Alarmed Carrier PDS, the carrier system is “alarmed” with specialized optical fibers deployed within the conduit for the purpose of sensing acoustic vibrations that usually occur when an intrusion is being attempted on the conduit in order to gain access to the cables.

Alarmed carrier PDS offers several advantages over hardened carrier PDS:

#Provides continuous monitoring 24/7/365
#Eliminates the requirement for periodic visual inspections
#Allows the carrier to be hidden above the ceiling or below the floor, since periodic visual inspections are not required
#Eliminates the need for the welding and epoxying of the connections
#Eliminates the requirement for concrete encasement outdoors 
#Eliminates the need to lock down [[manhole cover]]s
#Enables rapid redeployment for evolving network arrangements

Legacy alarmed carrier systems monitor the carrier containing the cables being protected. More advanced systems monitor the fibers within, or intrinsic to, the cables being protected to turn those cables into sensors, which detect intrusion attempts.

Depending on the [[government]] organization, utilizing an alarmed carrier PDS in conjunction with interlocking armored cable may, in some cases, allow for the elimination of the carrier systems altogether. In these instances, the cables being protected can be installed in existing conveyance (wire basket, ladder rack) or suspended cabling (on D-rings, J-Hooks, etc.).