Chapter 5: How to choose the right optical fiber cable Parameters General outline of the parameter involved in choosing the rigth optical fiber cable design.

First parameter: the optical fiber The four most common types of fiber in fiberoptic networks today (no specific order).

Primary coating Application of acrylate as the primary coating.

Acrylate as the primary coating Primary coated fiber.

The fiber characteristics after primary coating application The most common geometrical parameters for standard single-mode fiber 8–10/125 μm.

Maximum permissible stresses on a primary coated fiber.

Color-coding for optical fibers Color-coding scheme used by Telia AB, Sweden.

Second parameter: the buffers Loose tube buffer (loose fibers/ribbons in tube) A number of primary coated fibers or ribbons can lie loosely in a tube, which functions as a loose tube buffer.

Temperature variations The fibers can move freely within the loose tube buffer to compensate for temperature variations.

Areas of application for tight buffered fibers Fiber with tight buffer. Tight buffered fibers

Fiber ribbon technique: Encapsulating The three most common methods of manufacturing fiber ribbon.

Encapsulated ribbon fiber Manufacture Encapsulated fiber ribbon. The illustration shows a fiber ribbon with one layer of acrylate applied over primary coated fibers.

Tests Macrobend test Setup for macrobend test.

Torsion test Setup for torsion test.

Crush test Setup for crush test.

Process testing Strippability - random testing Example of good strippability (upper) and bad strippability (lower).

Separability - random testing Each individual fiber must be able to separate without damage to the individual primary coatings.

Fiber curl Fiber curl.

Attenuation Graphs showing OTDR attenuation plot at both 1310 nm and 1550 nm.

Geometry Geometry of a four fiber ribbon.

Parameters regarding the geometry of the fiber ribbon.

Third parameter: the strength member Aramide yarn Different types of strength member.

Fourth parameter: the cable core Cables with circular core Optical fiber cable, concentric construction, with loose tubes around the central strength member. Cable illustrated is the GRHLDV. Optical fiber cable; concentric construction with tight buffered fibers around the central strength member. Cable illustrated is the GNHLBDUV.

Cable with slotted core Slotted core profiles. From left to right S, Z and SZ stranding.

Three different types of slot profile.

Pitch of a slotted core cable Fibercreep due to temperature changes.

Expansion and contraction of cables The fiber can move freely.

Expansion and contraction caused by temperature variations Young's modulus, density and coefficient of linear thermal expansion of various materials used in optical fiber cables.

Four examples of optical fiber cables with slotted core. Cables illustrated are from the left: GRSLDV, outdoor cable with loose tube buffer. GNSLBDV, indoor/outdoor cable with tight buffered fibers GASLDV, outdoor cable with four fiber ribbon GASLDV, outdoor cable with eight fiber ribbon.

Optical fiber cable without a core The simplest optical fiber cable design is suitable for connecting cables and in data networks. The cable illustrated is GNLBDU. With a multiple of subcables and an extra sheath, this cable becomes a neat package of 24 GNLBD cables measuring only 15 mm in diameter. The cable illustrated is GNHLLBDU.

Fifth parameter: the water protection Metallic tube: Copper encapsulation Copper plate formed to a tube and electrically welded to a water-proof encapsulation.

Sixth parameter: sheathing The sheath has primarily the following functions: Provides mechanical protection Provides thermal insulation Protects against chemicals Provides moisture protection Protects from rodents. The plastic materials normally used for the sheath are: Standard polyethylene (PE) Flame retardant halogen-free materials Polyvinyl chloride (PVC) Polyamide (PA) Fluoroplastics Polyurethane (PU) Copper tube (Cu) Applying the final sheath:

Seventh parameter: extra reinforcement Corrugated steel tape Corrugated steel tape-reinforced cable for laying underground, or in ducts. The cables illustrated are GRSLWLV and GASLWLV.

Steel wire, steel tape Steel-reinforced cable for laying underground, e.g., by direct ploughing. The cable illustrated is GRSLTLV.

HET - heat expandable tape By using dielectric reinforcement, a completely metal-free cable can be manufactured for direct ploughing or laying underground. This cable is ideal for installations located in the vicinity of high voltage lines. The cable illustrated is GASLLDV, 192 fibers.

Aramide yarn Aramide yarn is used as longitudinal reinforcement in aerial cable for spans up to 250 m. The cable illustrated is GRLSDV. Aerial cable with a large amount of of aramide yarn as strength member. This type of cable is self suporting for spans up to m. Cable illustrated is the SkyspanTM (Focas Inc.).

Suspension strands With a steel suspension strand, optical fiber cable can be suspended in spans of m. The cable illustrated is GASLCV.

Optical ground wire, OPGW Optical power ground wire to replace the traditional ground wire on top of power lines. Cable illustrated is thr SkyliteTM (Focas Inc.).

Hybrid cables Two examples of hybride cable designed to be installed alongside the railway tracks.

A collection of newer types of cables Cable to be wrapped around ground wire or phase line Skywrap. Indoor cable with fiber ribbon, suited for FTTH etc. Outdoor cable with loose tube suited for FTTH etc.

Ribbon cable with 432 fibers.

Ribbon cable with 864 fibers.