A structured cabling system is a complete system of cabling and associated hardware, to provide a comprehensive communications infrastructure.
A communications infrastructure serves a wide range of uses, like providing telephone service or transmitting data through a computer network.
The structured cabling system begins at the point where the service provider terminates their services. This is the point of demarcation (DEMARC).
For example, in a telephone system installation, the SP furnishes one or more service lines (per customer requirements). The SP connects the service lines at the point of demarcation.
Every structured cabling system is unique, due to variations in:
- • architectural structure of the building, which houses the cabling
- • cable and connection products
- • function of the cabling installation
- • types of equipment the cabling installation will support
- • configuration of an already installed system (upgrades and retrofits)
- • Customer requirements
- • Manufacturer warranties
The recommended methods used to complete and maintain cabling installations should follow industry standards. The standardization of these installations is necessary because of the need to ensure acceptable system performance from increasingly complex arrangements.
The cabling industry accepts the American National Standards Institute (ANSI), in conjunction with TIA/EIA, as the responsible organizations for providing and maintaining standards and practices for structured cabling. ANSI has published a series of standards to design, install, and maintain cabling installations. Following these standards helps to ensure proper cabling installation.
The benefits of these standards include:
- • Consistency of design and installation
- • Conformance to physical and transmission line requirements
- • A basis for examining a proposed system expansion and other changes
- • Uniform documentation
Structured cabling installations typically include: entrance facilities, vertical and horizontal backbone pathways, vertical and horizontal backbone cables, horizontal pathways, horizontal cables, work area outlets, equipment rooms, telecommunications closets, cross-connect facilities, & multi-user telecommunications outlet assemblies (MUTOA).
The entrance facility includes the cabling components needed to provide a means to connect the outside service facilities to the premises cabling. This can include service entrance pathways, cables, connecting hardware, circuit protection devices, and transition hardware.
An entrance facility provides the transition from outside plant cabling to cabling within the building. The entrance facility is also the network DEMARC between the carriers and customer premises cabling. National and regional electrical codes govern placement of electrical protection devices at this point.
Some components of structured cabling are:
- • Cable pathways: shafts, conduits, raceways, and floor penetrations (such as sleeves or slots) that provide routing space for the cables.
- • The actual cables: optical fiber, twisted-pair copper, coaxial copper, or some combination of these.
- • Connecting hardware: connecting blocks, patch panels, interconnections, cross-connections, or some combination of these components, and
- • Miscellaneous support facilities: cable support hardware, fire-stopping and grounding hardware.
Connectors are as essential to the integrity of the entire telecommunications network as is the cable itself. Connectors align, attach, and decouple the media to a transmitter, receiver, another media of same or similar type, an active telecommunications device, or a specified passive telecommunications device.