FOA CFOS/O key terms

All fiber optic cable, hardware, and enclosures installed outdoors between buildings, including aerial, buried, and underground routes. OSP work is governed by harsher environmental, mechanical, and safety conditions than premises cabling.

A cable design in which fibers sit loosely inside gel-filled or dry tubes that are stranded around a central strength member. The loose construction isolates fibers from installation strain and temperature-driven expansion, making it standard for OSP routes.

A rigid rod, usually steel, fiberglass, or aramid-reinforced plastic, at the cable core that carries tensile installation loads and limits contraction. It keeps the fiber tubes centered and prevents buckling when the cable is pulled or blown.

A cable whose fibers are bonded side by side into flat ribbons, typically 12 fibers wide, stacked inside a tube. Ribbons allow high-count mass splicing with a single fusion operation, greatly reducing splice time in large OSP builds.

Cable wrapped with a corrugated steel or aluminum tape beneath the outer jacket to resist rodent damage, crush, and moisture intrusion. Armor must be bonded and grounded at splice points and terminations for electrical safety.

A cable containing a metallic conductor, such as a copper tracer wire or steel armor, that can be located from the surface with a tone generator and receiver. Non-toneable all-dielectric cable requires documented as-built records or marker tape for locating.

A fiber cable with no metallic components anywhere in its construction, eliminating lightning conduction and ground-loop paths. It is preferred in electrically hazardous or high-lightning areas but cannot be located with conventional metallic tone sets.

The protective plastic tube surrounding one or more fibers inside a cable, available loose or tight. In OSP cables, tubes are color-coded to identify fiber groups and are opened at splice points to access individual fibers.

The standardized 12-color sequence, blue, orange, green, brown, slate, white, red, black, yellow, violet, rose, aqua, used to identify individual fibers and buffer tubes. Correct code reading is essential for splicing the right fibers and documenting records.

Fiber cable installed on poles, typically lashed to a galvanized steel strand that supports its weight and wind loads. Aerial spans must respect sag, clearance, and loading rules, and cable is often installed with a lashing machine or pre-lashed design.

The galvanized steel wire or strand that supports aerial cable and carries its mechanical load. Cable may be lashed to it, figure-eight wrapped, or supplied as self-supporting figure-eight cable bonded to the messenger.

Fiber cable placed directly in a trench or plowed into soil, usually with warning tape or a tracer above it. Direct-buried cable needs rodent-resistant jacket and sufficient cover depth to protect against digging and frost movement.

A conduit, such as PVC, HDPE, or innerduct, that carries cable underground and protects it from soil, water, and mechanical damage. Ducts allow cable to be pulled or blown in and later replaced without excavation.

A smaller flexible subduct installed inside a larger conduit to divide it into separate channels. It lets multiple cables share one duct, reduces friction during installation, and simplifies future cable replacement.

A small underground enclosure large enough for a technician to reach in and work, but not to stand in, used for pulling, splicing, and storing slack. It is smaller than a manhole and often placed at duct direction changes.

A large underground vault with an opening that lets a technician enter to pull cable, splice, and manage slack. Manholes are used where duct routes converge or where access for large cable counts is needed.

A weatherproof enclosure that houses fusion splices and slack, protecting them from water, dust, and mechanical stress. Closures are available for aerial, buried, and vault mounting and are sealed with gaskets, tape, or heat-shrink.

A shallow tray inside a closure that holds spliced fibers in organized, protected loops and keeps bend radius under control. Trays stack in the closure and separate splice groups for easier re-entry and troubleshooting.

Extra cable length stored in a closure, handhole, or aerial coil so the cable can be re-spliced or re-terminated later. Slack must be coiled at a safe bend radius and secured so it does not kink or stress fibers.

The tensile force applied to a cable during installation, measured with a tension meter or breakaway swivel. Exceeding the cable's rated maximum can stretch fibers, cause loss, or break them, so pulls must be monitored and stopped at the limit.

A pulling accessory that connects the pull rope to the cable and releases at a preset tension, protecting the cable from over-pull. It also swivels to prevent twist from transferring into the cable.

A rope or pull tape pre-installed in a duct and used to draw cable through it. It must be strong enough for the load and attached through a swivel so twisting does not damage the cable.

A water-based or compatible compound applied to cable and duct to reduce friction during a pull. Correct lubricant choice lowers pulling tension and prevents jacket damage or chemical incompatibility with the cable.

An installation method that uses compressed air or gas to float cable through a duct while a feeder pushes it forward. Blowing reduces pulling tension and is well suited to long duct runs and microduct installations.

A small-diameter flexible tube, often 5 to 12 mm, that carries air-blown microcable or individual fibers. Microduct networks allow incremental fiber deployment by blowing cable into ducts as demand grows.

The process of tying aerial cable to a messenger strand with a spiral-wrapped wire or filament using a lashing machine. Proper lashing keeps the cable supported, aligned, and free of abrasion along the span.

The distance between two adjacent supporting poles on an aerial route. Span length, sag, and cable weight determine the tension on the messenger and the clearances that must be maintained.

The minimum curve a fiber or cable can tolerate without added loss or damage, usually stated as a multiple of cable diameter. Violating bend radius during pulling, coiling, or routing causes macrobend loss and possible fiber breakage.

Joining two fibers by melting their ends together with an electric arc in a splicer. A good fusion splice has very low loss, typically under 0.1 dB, and high mechanical strength when properly protected.

A splice that aligns and holds two cleaved fibers in a precision sleeve using an index-matching gel or adhesive. It needs no fusion splicer but generally has higher loss and is used for restoration or temporary repairs.

The instrument that aligns fiber ends, applies an arc to fuse them, and estimates splice loss. Proper electrode condition, arc calibration, and cleave quality determine splice results.

Scoring and breaking a fiber to produce a flat, perpendicular end face for splicing or connectorizing. A poor cleave angle or chip causes high splice loss or connector failure.

A heat-shrink tube with a steel rod that covers a completed splice and is shrunk in the splicer's heater. It protects the bare fiber joint from bending and mechanical damage and is stored in the splice tray.

The optical power lost at a splice, caused by alignment error, cleave quality, core mismatch, or contamination. It is measured bidirectionally with an OTDR and should be within the project's acceptance threshold.

Fusing an entire ribbon of fibers in one operation with a ribbon splicer. It dramatically speeds high-count splicing but requires precise ribbon preparation and consistent cleave quality across all fibers.

The polished or cleaved tip of a fiber connector that mates with another connector. Its geometry and cleanliness determine insertion loss and backreflection, and it must be inspected and cleaned before every mating.

A magnifying instrument, typically 200x to 400x, used to examine connector end-faces for scratches, pits, cracks, and contamination. Inspection before mating prevents transferring dirt and permanent damage to the ferrule.

A pen-style tool that advances a lint-free cleaning tape across a connector end-face with one push. It removes dust and oil without solvent and is the standard field method before mating connectors.

The decrease in optical power caused by inserting a component, such as a connector, splice, or cable segment, into a link. It is expressed in decibels and measured against a reference with a light source and power meter.

The maximum allowable total loss for a fiber link, calculated from cable attenuation, splice loss, connector loss, and margin. Measured loss must stay below the budget for the link to pass acceptance testing.

An instrument that sends light pulses into a fiber and analyzes backscattered and reflected light to locate loss events and faults by distance. It characterizes splices, connectors, bends, and breaks along the route.

The minimum distance after a reflective event, such as a connector, in which the OTDR cannot detect another event. Short pulse widths reduce dead zones but lower dynamic range.

Measuring a link from both ends and averaging results to remove the directional bias of splice loss readings caused by backscatter differences. It is required for accurate splice loss acceptance in OSP testing.

Using OTDR traces, visual fault locators, or loss measurements to identify the distance and nature of a break, bend, or high-loss point. Accurate records and fiber assignments speed locating and repair.

A visible red laser source used to find breaks, tight bends, and bad connectors by the glow or leakage of light through the jacket. It is a quick field aid but works only over limited distances.

Loss caused by bending a fiber tighter than its minimum bend radius, which lets light escape from the core. It appears as a sudden loss increase at a specific point and is found with an OTDR or visual fault locator.

A space such as a manhole or vault with limited entry and exit that is not designed for continuous occupancy. Entry requires atmospheric testing, ventilation, a permit, an attendant, and rescue provisions.

A portable instrument that tests a confined space for oxygen deficiency, combustible gas, hydrogen sulfide, and carbon monoxide before and during entry. Readings must be recorded and the space ventilated until safe.

The procedure of isolating and tagging energy sources, such as power or pressurized air, before work begins. It prevents accidental energizing or release that could injure technicians working on the plant.

Bonding metallic cable armor, messengers, and hardware to earth to prevent hazardous voltages and lightning surges from reaching people and equipment. Grounding must follow the project's standards at every splice and termination.

The final record drawings and fiber assignments showing actual cable routes, splice locations, and port-to-port connections. Accurate as-builts speed fault location, future splicing, and locating non-toneable cable.