Optical Fiber Cabling Systems
Optical fiber are ultra-pure glass strands that provide a path to support the transmission
of light pulses instead of electrical signal.
Optical fiber cable is constructed of ultra-pure glass fiber strands.
Two main elements of an optical fiber strand are its core and cladding.
Optical Fiber Classification
Single mode Optical Fiber
Single mode optical fiber supports one mode of light travel normally using a laser light
source.
Core size: 8 to 11 µm.
Used in riser and campus environments for backbone distribution. Not recognized for
use in horizontal distribution.
Supports distance up to 9840ft (3000m).
Multimode Optical Fiber
Multimode optical fiber cable is the most common optical fiber choice for backbone and
horizontal distribution within building and campus environments.
The TIA-568-C now recommending 850 nm laser-optimized 50/125 µm.
Optical Fiber Color Codes
In Accordance With EIA/TIA 598
For Cable Larger Than 12 Fiber And Higher, The Color Code Is Repeated.A Black Stripe Or
Dash Is Added.
Optical Fiber Strands, Binder Colors
Optical Fiber Cable Marking
Optical fiber cables must be listed and marked in accordance with their fire resistance rating.
Cable Substitution
From a fire resistance standpoint, a higher rating can be substituted for any lower rating, but
not vice versa (OFNG and OFN are interchangeable for NEC purposes.
Types OFNP and OFCP non-conductive and conductive optical fiber plenum cables shall
be listed as being suitable for use in ducts, plenums and other space being used for
environmental air and be listed as having adequate fire and low smoke producing
characteristics
TYPE OFNR and OFCR non-conductive and conductive optical fiber riser shall be listed as
suitable for use in vertical run in a shaft or from floor to floor and shall be listed as
having the fire resistant characteristics capable of preventing the carrying of fire from
floor to floor.
TYPE OFNG and OFCG non-conductive and conductive general purpose optical fiber
cables shall be listed as being suitable for general purpose use, with exception of risers
and plenums, and shall be listed as being resistant to the spread of fire.
TYPE OFN and OFC non-conductive and conductive optical fiber cables shall be listed as
being suitable for general purpose use, with the exception of risers and plenums, and
other spaces used for environmental air, and shall be listed being resistant to the spread
of fire.
Optical Fiber Cable Design
Premise Fiber Cable is designed strictly for indoors use and must be listed the
requirements of local building codes. In most cases, optical fiber used inside building will
be tight buffered cable.
Tight Buffered Cable protects the fiber by supporting each optical strand within a 900
µm coating.
Armored Cable or interlocked armor optical fiber cable provide for an extremely well
protected cable ideally for harsh environment. E.g. high traffic areas where added
protecion and security are required.
Indoor/Outdoor (I/O) Optical Fiber Cable utilize materials that provide better
temperature properties and UV protections. Primary advantage of the cable is the ability
to transition from outdoor to indoor environment with the same cable, eliminating a
need for splicing or cross-connection.
Outside Plant (OSP) Optical Fiber Cable is designed especially for outdoor use. OSP fiber
cable typically employ a loose tube fiber construction, however tight buffered
construction may be sude depending on the need for a specific application (e.g. tactical
or military fiber)
Loose Tube optical fiber construction, there is no tight buffer around fiber.
Ribbon Cables
Ribbon cables or ribbon fiber is a high-density design used for both premise and OSP
environments.
Optical Fiber Connectors
Optical fiber connectors provide the following critical functions:
Minimal power loss when mating to other cables or equipment
Secure optical fiber retention
Protects the end of the fiber
The ability to connect and disconnect form the other cables or equipment
Two important qualities of a connector are ability to latch securely and connect to other
cables or equipment with low loss.
Common Connector Types
Straight Tip (ST) , Subscriber Connector (SC), Small Form Factor (SFF) , Latching
Connector (LC), Transfer Registered Jack (MTRJ).
Array Connectors
Array connectors are high density connectors that terminate 4 to 24 fibers in a ferrule.
Commonly used in data centers.
Mating Connectors
Optical Fiber Adapter Plate
Fiber Optics Patch Panel
Optical Fiber Patch Cord
Two types of patch cords available: Simple fiber cord and Duplex fiber cord
Duplex are common for patching two strand required to transmit and receive
information over a optical fiber.
Can be standard and hybrid combination with single mode and multi-mode ST,SC, FC,LC
and MTRJ connectors
length size: 1, 2,3,5 and 10 m
Backbone Cabling System
The term backbone is used to describe cables that handle the bulk of the telecom traffic.
The function of backbone is to provide interconnection between entrance facilities (EF),
telecommunication room (TR), equipment room (ER) and telecommunication enclosure
(TE) in structured cabling system.
Consist of the cables, pathways, intermediate and main cross connects, connecting
hardware, termination and patch cord or jumpers used for backbone-to-backbone cross
connection.
Also support facilities including cable support hardware, firestopping and
ground(earthing) hardware.
Two types of backbone cable
Interbuilding backbone cable is defined as a cable that handles traffic between
buildings.
Intrabuilding backbone cable is defined as a cable that handles traffic between
TRs within a single building.
Network Topology
Star topology for backbone distribution
Commonly used for backbone distribution
There are administrative levels of backbone cabling. A first level backbone that installed
between a main cross-connect (MC) and an intermediate cross-connect (IC) or a
horizontal cross-connect (HC). A second level backbone is a cable that is installed
between an IC and an HC.
Backbone Cross-Connect
A backbone topology shall no more than two level of cross connections.
Three types of Cross Connection
Main cross-connect (MC) is the cross connect in the ER for connecting entrance cables,
backbone cables and equipment cables.
Intermediate cross-connect (IC) are the cross-connect points located between the MC
and the HC in interbuilding backbone cabling.
Horizontal cross-connect(HC) is a location for the cross-connect of horizontal cabling to
other cabling and equipment.
Horizontal Cabling System
The term horizontal cabling refers to the cable that runs through the ceiling or under the
floor of a building.
Horizontal cabling system may be described as either a permanent link or as a channel
link
Permanent links contains all of the horizontal cabling components excluding any
equipment cords , patch cord or interconnect. The maximum allowable horizontal
cabling length in a permanent link is 90 m (295 ft).
Channel link contains all of the components used in the horizontal cabling system. Allow
up to 10m (33ft) of patch cord to be added to the permanent link for cross connection
and interconnection. Total allowable channel link length is 100m (328ft).
Patch Cords
A total of three patch cords are allowed in standards compliant channel link.
Not exceed 10 meters (33 ft)
No single path cord length shall not exceed 5m(16 ft)
Patch cords in the HC: shall not exceed 5m (16 ft). Two(2) patch cords use in the HC
Patch cord in the work area shall not exceed 5m(16 ft)
Telecommunication Outlet/connector shall be a minimum four pair or shielded 100 ohm
Category 5e or higher is recommended.
Optical Fiber in the Work area
TIA 568-C Standard recommends that laser 850 nm laser optimized 50 µm optical fiber
(OM3) be installed as the
multimode fiber for
commercial building
Single mode optical fiber
(OS1) is not permitted in
horizontal cable system.
A duplex optical fiber outlet/connector shall used in work area. Recommended to use
duplex SC connector.
Horizontal cable at the telecommunications outlet/connector shall be labeled within 6
inches of cable termination.
Consolidation Points
A consolidation Points is an interconnection point between the permanently installed
horizontal cable extending from the HC in the TR, and the horizontal cables extending to
the telecommunication outlet/connectors or MUTOAs.
A transition points (TP) is described as a location in the horizontal cabling where flat
undercapet cable (CMUC) connect to round cable.
Multi-User Telecommunications Outlet Assembly (MUTOA) – a standard allows the use
in open office spaces that are frequently reconfigured.
A MUTOA allows for horizontal cabling to remain intact when the office plan is changes.
multiple work areas can be served by one or more MUTOAs.
For Twisted pair cabling, MUTOAs shall be located at least 15m (50ft) from the HC to
minimize the effect of multiple connections in the close proximity on near-end crosstalk
(NEXT) and return loss
A MUTOA may be only be used for making direct connections to work area equipment.
Never use a MUTOA as a cross-connect point
Maximum patch cord lengths
The use of a MUTOA cabling design option allows work area cable extend beyond 5m(16 ft)
depending on the length of the horizontal cable.
