What are the six components of structured cabling?

The six major components of structured cabling are entrance facilities, equipment rooms, backbone cabling, telecommunications rooms, horizontal cabling, and work areas.

In past decades, the wiring of voice and data communication systems was far less complex than it is today. Most systems used two or four pairs of copper wire wrapped in strapping to protect the cable. Connections typically involved stripping the ends of the wires to expose the copper conductors. This was then connected to a set of connectors, often called junction blocks. These connected the physical equipment to the switching equipment, such as a PBX system.

In the late 1970s and early 1980s, as digital transmission grew in nearly every type of voice and data communications equipment, new types of cabling and connectors emerged. The idea was to simplify the process of connecting equipment to its primary system, hoping to speed up the process of building a wired infrastructure for voice and data equipment.

What is a structured cabling system?

As cabling and connection points evolved, more standardization was needed for cabling, connectors, and different types of cabling, including copper, fiber, and coaxial. The American National Standards Institute and the Telecommunications Industry Association developed a series of standards, ANSI/TIA-568, to introduce guidelines for various aspects of cable distribution systems in residential and commercial buildings.

These standards shape the structured cabling system. Structured cabling is based on six components that together provide a convenient, repeatable, and easy-to-implement framework for installing telecommunications cabling. The six components of structured cabling are as follows:

• Entrance facilities
• Equipment room
• Backbone Cabling
• Telecommunications room
• Horizontal Cabling
• Work Area

Why is structured cabling important?

Structured cabling greatly simplifies the installation of the cable infrastructure that supports a wide range of voice and data communications equipment. Whether installing a coaxial jack in a home or wiring a skyscraper, all components are manufactured to specific standards for electrical transmission, resistance, cable length, connectors, and cable manufacturing.

Structured cabling also enhances troubleshooting of cabling problems when using diagnostic equipment that complies with ANSI/TIA-568.0/1 standards. Installation is also easier with structured cabling because the interfaces are standardized, typically using plug-in connectors.

Structured Cabling Standards

The release of the ANSI/TIA-568 standard in 1991 greatly promoted the development of structured cabling systems. Its parts include Common Telecommunications Cabling for User Premises (C.0) and Standard for Telecommunications Infrastructure for Commercial Buildings (C.1). Both standards have been updated many times in the past 30 years, and the current iterations are ANSI/TIA-568.0 (User Premises) and ANSI/TIA-568.1 (Commercial Buildings). Both were last updated in March 2020.

Benefits of structured cabling

Structured cabling greatly simplifies the installation, troubleshooting, and maintenance of the cable infrastructure. This saves money by standardizing all hardware components and cable types. It also saves time installing connectors and greatly simplifies wiring. The ANSI/TIA-568 standard is suitable for almost any type of residential and commercial wiring requirements.

Six structured cabling subsystems

1. Entrance Facility (EF). The telecommunications facility that enters a building or residence from the outside (such as a local service provider or private network) is routed through an opening in the exterior wall through conduit. This cabling enters a room where other equipment is deployed, including network connection points, patch panels, equipment racks, hardware connectors, power supplies, and protection for grounding, shielding, and lightning protection.

2. Equipment Room (ER). The area where the entrance cabling connects to the building's internal cabling infrastructure is the equipment room. It houses the patch panels that provide connections for backbone cabling, horizontal cabling, and intermediate cabling. Because the equipment room may also house network switches, PBXs, servers, and other equipment, it should be environmentally controlled to ensure that the temperature and relative humidity levels remain within the equipment vendor's specifications.

3. Backbone cabling. Also called riser cabling because it is usually installed in vertical channels or risers that connect to each floor - backbone cabling connects EF, telecom and other ER and carrier spaces. Backbone cabling defines two subsystems:

• The wiring subsystem 2 is the wiring between the horizontal cross-connect and the intermediate cross-connect (IC).
• The wiring subsystem 3 is the wiring between the IC and the main cross-connect (MC).

The types of cables used in backbone cabling include the following:

• 100 ohm twisted pair: Cat3, Cat5e, Cat6 or Cat6a;
• Multimode fiber cabling: 850nm laser optimized 50/125μm; 62.5/125μm and 50/125μm;
• Single-mode fiber cabling.

Note: The entry cable is usually determined by the operator and is not the user's responsibility.

The six components of structured cabling and how they interconnect.

4. Telecommunications Room (TR) and Telecommunications Cabinet (TE). This environmentally controlled area can be a dedicated room (TE) or part of another larger room (TR), such as a general utility room. The hardware in these spaces terminates horizontal and backbone cables. This is also where local cables called jumpers are used at patch panels to cross-connect different cables. ICs or MCs can also be installed here to provide additional connection resources.

5. Horizontal Cabling (Cabbing Subsystem 1). Providing telecommunications resources to the user's workspace or other rooms on the same floor is the job of horizontal cabling. A typical cable run runs from the user's equipment to the nearest computer room on the same floor. Regardless of the cable type, the maximum cable length allowed between the computer room and the user's equipment is 295 feet.

Horizontal cabling includes cables, connectors, patch panels, patch cords and patch cords in TR/TE. They may also include multi-user telecommunications jack assemblies and integration points to connect multiple devices or cables in a single connector.

Cable types used in horizontal cabling include:

• Four pairs of 100-ohm unshielded or shielded twisted pair in Cat5e, Cat6, or Cat6a;
• Multimode fiber cabling, dual fiber (also with higher fiber counts);
• Single-mode fiber cabling, Dual-fiber (also with higher fiber counts).

6. Work Area (WA). The area from the connector or jack in the wall socket to the user equipment using the cable is considered as WA. It is the final destination of the integrated cable system.

Structured cabling greatly simplifies the process of installing voice and data communications equipment. Its continued use means that new devices such as IoT systems will be easily supported.