CaTV | Backbone Distribution System

 

 

The backbone system consists of connections between entrance facilities, equipment rooms and telecommunications closets. Backbone systems are often referred to as riser systems because in many installations the bulk of the system, especially the cable, is installed in a vertical riser. In multistory buildings, for example, the backbone connects the equipment or computer room in the basement with telecommunications closets located on every floor.

The backbone cabling system provides interconnection between entrance facilities, headend equipment room and horizontal distribution system within the building. These includes backbone cables - coaxial cable, fiber optic cable, and copper cable. RF amplifiers, Optical Nodes, Optical Line Termination (OLT), Power supply, Network Access Point (NAP), Cable Modern Termination System (CMTS), and Optical Distribution Frame (ODF). This cabling system also extends between buildings in a campus environment.

The type of cable for a backbone depends on the network topology used. The network could be a tree-and-branch architecture (coaxial network), hybrid-fiber coaxial network (HFC), or fiber-to-the-home (FTTH). A copper based network can also be used to deliver video services but in an IP based format.

In the campus setting, the backbone may run horizontally, connecting different entrance facilities or remote telecommunications closets. In some applications, then, there is no real difference between the terms "horizontal" and "vertical." Physical topologies may vary, and sometimes the used topology won`t fit the assumptions about what a backbone is.

The central requirement of a backbone system is it is be able to support different  applications, from voice transmission to high-speed data and multimedia networks. To meet those requirement, system designers and installers must use foresight when planning a backbone system. Installations today have to anticipate future growth and prospective applications as well as current needs. For this reason, many backbone installations depend on optical fiber, and can include hundreds of fibers, if not actual cables. Another recent trend is to install hybrid fiber-optic cables in the backbone, terminating and using the multi-mode fibers but leaving the single-mode fibers dark, or unused, to support future needs.

Backbone cabling systems that are being installed can usually be classified into one of four different topologies, each of which has its own characteristics. To properly install these systems--Ethernet, token ring, fiber distributed data interface, and asynchronous transfer mode--it is essential to know, at least in a general way, how they function.

DragonsDean Enterprise | Speak to a Specialist