As wiring and connection points evolved, more standardization was needed for cabling, connectors and the different types of wiring, including copper, fiber and coaxial. The American National Standards Institute and Telecommunications Industry Association set forth a series of standards, ANSI/TIA-568, to introduce guidelines for all aspects of residential and commercial building cable distribution systems.
These standards shape the structured cabling system. Structured cabling is based on six components that, together, provide a convenient, repeatable and easily implemented framework for installing telecommunications cabling. The six components of structured cabling are the following:
Entrance Facilities
Equipment Room
Backbone Cabling
Telecommunications Room
Horizontal Cabling
Work Area
Why is structured cabling important?
Structured cabling greatly simplifies the installation of a cable infrastructure that supports a wide variety of voice and data communications equipment. Whether installing a coaxial outlet in a home or wiring a skyscraper, the components are all made to specific standards for electrical transmission, resistance, cable lengths, connectors and cable fabrication.
Structured cabling also enhances troubleshooting of wiring problems when using the proper diagnostic equipment, which is designed to be compatible with the ANSI/TIA-568.0/1 standards. Installation is also easier with structured cabling because the interfaces are standardized, typically using snap-in connectors.
Structured cabling standards
The development of structured cabling systems was greatly helped with the release of the ANSI/TIA-568 standard in 1991. Its sections included Generic Telecommunications Cabling for Customer Premises (C.0) and Commercial Building Telecommunications Infrastructure Standard (C.1). The two standards have been updated numerous times in the past 30 years, and the current iterations are ANSI/TIA-568.0 (customer premises) and ANSI/TIA-568.1 (commercial buildings). Both were most recently updated in March 2020.
Structured cabling benefits
The installation, troubleshooting and maintenance of cable infrastructures are greatly simplified with structured cabling. This saves money through standardization of all hardware components and cable types. It also saves time with installation as connectors and their wiring are greatly simplified. The ANSI/TIA-568 standard is adaptable to virtually any kind of residential and commercial wiring requirements.
The six structured cabling subsystems
1. Entrance Facilities (EF). Telecom facilities entering a building or residence from the outside -- from a local service carrier or private network -- pass through an opening in the exterior wall via a conduit. This cabling enters a room where other devices are deployed, including network connection points, patch panels, equipment racks, hardware connectors, power supplies and protection devices for grounding, shielding and lightning protection.
2. Equipment Room (ER). The area where entrance cabling connects to the internal building wiring infrastructure is the equipment room. It houses patch panels that provide connections for backbone cabling, horizontal cabling and intermediate cabling. As this room may also house network switches, PBXs, servers and other devices, it should be environmentally controlled to ensure that temperature and relative humidity levels are maintained according to equipment vendor specifications.
3. Backbone Cabling. Also called riser cabling -- as it typically is installed in vertical channels, or risers, that connect to each floor -- backbone cabling links EF, telecommunications and other ERs, and carrier spaces. Two subsystems have been defined for backbone cabling:
Cabling Subsystem 2 is cabling between a horizontal cross-connect and an intermediate cross-connect (IC).
Cabling Subsystem 3 is cabling between an IC and the main cross-connect (MC).
The cable types used in backbone cabling include the following:
100-ohm twisted-pair cabling: Cat3, Cat5e, Cat6 or Cat6a;
multimode optical fiber cabling: 850 nanometer laser-optimized 50/125 micrometer (recommended); 62.5/125 μm and 50/125 μm (permitted); and
single-mode optical fiber cabling.
