Standard of Structured Cabling System Areas

Written by Julianus Yu

The ANSI/TIA/EIA-568-B Standard breaks structured cabling into seven areas. They are the horizontal cabling, backbone cabling, the work area, telecommunications rooms, equipment rooms, entrance facility (building entrance), and Administration.

Horizontal Cabling
Horizontal cabling, is the cabling that extends from telecommunications rooms to the work area and terminates in telecommunications outlets (information outlets or wall plates). Horizontal cabling includes the following:

• Cable from the patch panel to the work area
• Telecommunications outlets
• Cable terminations
• Cross-connections (where permitted)
• A maximum of one transition point

Backbone Cabling
Backbone cabling is necessary to connect entrance facilities, equipment rooms, and telecommunications rooms. Backbone cabling is also sometimes called vertical cabling, cross-connect cabling, riser cabling, or intercloset cabling. Backbone cabling consists of not only the cables that connect the telecommunication rooms, equipment rooms, and building entrance but also the cross-connect cables, mechanical terminations, or patch cords used for backbone-to-backbone cross-connection.

Work Area
The work area is where the horizontal cable terminates at the wall outlet (telecommunications outlet). In the work area, the users and telecommunications equipment connect to the structured-cabling infrastructure. The work area begins at the telecommunications area and includes components such as the following:

• Patch cables, modular cords, fiber jumpers, and adapter cables
• Adapters such as baluns and other devices that modify the signal or impedance of the cable (these devices must be external to the information outlet)
• Station equipment such as computers, telephones, fax machines, data terminals, and modems

The work-area wiring should be simple and easy to manipulate. In today’s business environments, moves, additions, and removal of equipment are frequent. Consequently, the cabling system needs to be easily adaptable to these changes.

Telecommunications Rooms
The telecommunications room is the location within a building where cabling components such as cross-connects and patch panels are located. Horizontal cabling is terminated in patch panels or termination blocks and then uses horizontal pathways to reach work areas. The telecommunications room may also contain networking
equipment such as LAN hubs, switches, routers, and repeaters. Backbone-cabling equipment rooms terminate in the telecommunications room.

Equipment Room
Equipment Room is a centralized space specified to house more sophisticated equipment than the entrance facility or the telecommunications rooms. Often, telephone equipment or data-networking equipment such as routers, switches, and hubs are located there. Computer equipment may possibly be stored there.

Entrance Facility
All external cabling (campus backbone, interbuilding, antennae pathways, and telecommunications provider) should enter the building and terminate in a single point. Telecommunications carriers are usually required to terminate within 50 feet of a building entrance. The entrance facility may share space with the equipment room, if necessary or possible. Telephone companies often refer to the entrance facility as the demarcation point. Some entrance facilities also house telephone or PBX (private branch exchange) equipment.

Administration areas
Administration area purpose is to provide a uniform administration scheme that is independent of application, which may change several times throughout the life of a building.