The term “backbone cabling” comes from the TIA/EIA-568C structured cabling standard. Structured cabling standard is a generic communication wiring scheme that is installed in a single building or cluster of buildings that is capable of supporting all forms of communication systems including: telephone systems, local area network computer systems, video systems, and imaging systems.
A structured cabling system includes all the cabling, cable pathways, ground and bonding systems, supporting structures, and building spaces, etc. It is based on a concept of modular subsystems that are independent yet work together to create a complete building cabling system. Each subsystem is designed and installed independently of the other subsystems. Then all of them are interconnected and work together as a single cabling system.
The subsystems include: work area subsystem, horizontal cabling subsystem, backbone cabling subsystem, telecom rooms, equipment rooms, and entrance facility.
In this video, I will explain the backbone cabling system.
Backbone cabling is the cabling that connects all of the building and campus telecom rooms together. Backbone cabling is also called vertical and riser cabling because backbone cables are usually installed vertically in a riser shaft to connect Telecom Rooms together in a multistory building.
This picture clearly shows what parts that backbone cabling covers.
It includes the backbone cables, such as twisted-pair copper cables, fiber optic cables, etc.; the backbone cable pathways that are used to support and distribute backbone cables, such as conduits, vertical shafts, raceway, etc.; the terminating hardware in the Telecom Room, such as patch panels, punch down blocks, etc.; the grounding and bonding devices to ground the backbone cables that have metallic part in it; and the cross-connections and jumper cables to provide connections to other backbone or horizontal cables in the telecom room.
The backbone cabling ties all of the different subsystems together to create an integrated configuration. The TIA/EIA-568C requires that backbone cables be installed in a hierarchical star topology as seen in the picture.
Each horizontal cross-connect in a Telecom Room is connected either directly to an Main Cross-Connect or to an Intermediate Cross-Connect and then to the Main Cross-Connect.
Backbone cables can be defined as intra-building cables and inter-building cables.
Intra-building cables connect closets together in a multistory building as well as closets on the same floor. Intra-building cables are installed inside a building.
Inter-building cables connect buildings together in a campus environment. Inter-building cables are installed between buildings.
Backbone pathways are the cabling facilities that are designed to hold, protect, support, and provide access to the backbone cables installed between telecom rooms. Backbone pathways must be designed and installed to support backbone cables for all types of communication systems.
Designing and installing the backbone pathway is extremely important because the pathway will always exist even if the backbone cables are changed.
A well designed and installed backbone pathway will enable backbone cables to be changed easily and with the least amount of disruption to communication systems and cost.
Several different types of pathways are shown here. Sleeve are sections of conduit that connect vertically aligned closets in a multistory building.
Metal conduits are installed as a direct run between two telecom rooms, or between a telecom room and an equipment room.
The third picture shows a metal conduit that is run between two buildings. It is also called an underground pathway.
Backbone cables installed in a sleeve or in a slot must be properly firestopped after the cables are in place. Firestopping is the process of creating a fire-rated barrier that will prevent both fire and smoke from spreading between floors in the event of a fire.
Firestopping installes specialty fire rated materials into penetrations to create the new barrier.
Copper cables and optical fiber cables that have any metallic elements in it must be bonded and grounded in each telecom room. As shown in this picture, a multipair UTP cable that has a metallic cable shield is bonded to a dedicated ground in the telecom room, this dedicated ground device is called Telecommunications Grounding Busbar, or TGB.
The metallic cable shield should be bonded to the TGB using a 6 AWG insulated conductor.
So there you have it. Please don’t forget to visit http://www.fo4sale.com for more free fiber optic tutorials.
Post time: Aug-22-2016