Reference · Glossary · 17 Terms
Glossary: B
Outside plant terms that start with B, in plain language, with links to the OSP map and the operations steps.
Backbone
Also Called: Trunk
High-count fiber that links central offices, hubs and major splice points.
- See Also: Feeder, Distribution
Backreamer
Also Called: Reamer
A cutting tool pulled back through the pilot hole to enlarge it for the product. It is sized for the product per the engineer or manufacturer; for a conduit bundle, from the bundle's outside diameter, not one conduit's.
- On the Map: Backreamer
- SOP Step: UG-07 Reaming and Pullback
- See Also: Product, Pullback, Pre-Ream
Backscatter
Also Called: Rayleigh Backscatter
Light the glass scatters back toward the OTDR along the whole fiber. Its slope on the trace shows attenuation, and a backscatter mismatch between two spliced fibers causes gainers.
- SOP Step: SPL-11 Testing and Acceptance
- See Also: OTDR, Attenuation, Gainer
Bend Radius
Also Called: Minimum Bend Radius
How tightly a cable may bend without damage or added loss. TIA-568.3 sets a minimum for OSP cable as a multiple of its outside diameter, larger while pulling than at rest; the cable's data sheet governs.
Bend-Insensitive Fiber
Also Called: G.657
Single-mode fiber that loses less light in tight bends (ITU-T G.657), used in drops and terminals. Splice it with the splicer program for the fiber types being joined, per the splicer manufacturer's instructions.
- SOP Step: SPL-07 Fusion Splicing (Single Fiber)
- See Also: Single-Mode Fiber, Macrobend
Bidirectional Average
Also Called: Bidirectional Averaging · Two-Way Average
A splice's true loss: the OTDR readings from both ends added and divided by two. One-direction readings can show a gainer or an exaggerated loss.
- SOP Steps: SPL-11 Testing and Acceptance, SPL-12 Documentation and Handoff
- See Also: Gainer, OTDR, OTDR Trace
Bill of Materials
Also Called: BOM
The list of every material and quantity on a job, issued with the prints. Final quantities are reconciled against it for payment.
- See Also: As-Built, Statement of Work
Birthmark
Also Called: Pole Brand
The brand burned or stamped on a pole by the maker, showing class, height, treatment, species and year. Surveyors read it to confirm pole records.
- On the Map: Pole Tag and Birthmark
- SOP Step: AE-02 Field Survey and Make-Ready Engineering
- See Also: Pole Tag, Pole Class
Bisect Guy
Also Called: Bisector Guy
A guy and anchor placed on the bisector of a line angle to balance the pull at a corner pole.
- On the Map: Corner Pole and Bisect Guy
- SOP Steps: AE-06 Anchors, AE-07 Down Guys and Guy Guards
- See Also: Corner Pole, Down Guy, Transverse Load
Bonding
Also Called: Bond · Grounding
Connecting metallic parts, such as strand, cable armor and closure hardware, to each other and to ground so they stay at the same potential. Missing bonds are a shock hazard.
Bore Log
Also Called: Drill Log
The record of a bore's readings along its path, usually rod number, distance, depth and pitch at every rod. It becomes the depth data on the as-builts.
- On the Map: Directional Bore Path
- SOP Steps: UG-06 Pilot Bore and Tracking, UG-13 Documentation and Closeout
- See Also: As-Built, Pilot Bore
Bore Profile
Also Called: Bore Plan
The side view of a planned bore: entry and exit points, entry angle, depth along the path, and clearance at each potholed crossing.
- On the Map: Directional Bore Path
- SOP Steps: UG-04 Potholing (Daylighting), UG-05 Bore Planning and Rig Setup
- See Also: Pilot Bore, Entry Angle, Potholing
Breakaway Link
Also Called: Weak Link · Fuse Link
A sacrificial link in the pullback string that breaks before the pull stretches any conduit past its safe pull strength. For a conduit bundle, the rating comes from a written basis from the conduit and pulling-head manufacturers or the engineer; without one, a fallback still under SME review is to rate the link below the lowest safe pull strength of any one conduit; confirm with the engineer.
- On the Map: Breakaway Link
- SOP Step: UG-07 Reaming and Pullback
- See Also: Conduit Bundle, Safe Pull Strength, Swivel
Breakaway Swivel
A swivel with a built-in break rating placed between the pull line and the cable, so it parts before the cable is overpulled.
- SOP Step: UG-11 Cable Placement Underground
- See Also: Pulling Tension, Swivel
Bucket Truck
Also Called: Aerial Lift · Bucket
A vehicle-mounted aerial lift used to reach strand and attachments. Outriggers go on firm ground per the manufacturer's instructions, and the basket follows the OSHA aerial lift rules (29 CFR 1926.453 for construction work, 29 CFR 1910.67 otherwise) and the employer's safety program.
- SOP Step: AE-04 Site Safety and Traffic Control for Aerial Work
- See Also: Qualified Electrical Worker
Buffer Tube
Also Called: Tube
The color-coded tube inside a loose-tube cable that carries the fibers, identified with the TIA-598 sequence.
- On the Map: Buffer Tubes and Color Code
- SOP Steps: SPL-03 Closure and Cable Preparation, SPL-05 Fiber Identification and Routing
- See Also: Loose Tube, Fiber Color Code, Tracer
Buried Drop
Also Called: Underground Drop
A drop cable or duct buried from a pedestal, flowerpot or handhole to the building.
- On the Map: Buried Drop
- SOP Step: UG-11 Cable Placement Underground
- See Also: Drop, Flowerpot