Network Cabling Fundamentals: Twisted Pair, Fiber Optics, and Connectors

Metallic Twisted Pair Cables and Coaxial Systems

Twisted pair cables use a couple of conductors for both transmission and reception. If they are not shielded, they are very sensitive to interference. A way to overcome this interference is to weave (twist) the pairs so that the electromagnetic disturbances affecting one conductor are nullified by the adjacent conductor.

Types of Twisted Pair Cables

• UTP (Unshielded Twisted Pair): A twisted pair cable without external metallic coating, making it sensitive to interference.
• STP (Shielded Twisted Pair): Similar to UTP, but includes a metallic coating (shielding) to prevent external interference.

Optical Fiber Systems

Optical fiber allows the transmission of light signals. Fiber is usually made of glass or other plastic materials, making it insensitive to external electromagnetic interference.

Components Required for Optical Transmission:

• Laser Source
• Light Emitting Diodes (LEDs)

Standard Network Connectors

The connector serves as the interface between the cable and the Data Terminal Equipment (DTE) or Data Circuit-terminating Equipment (DCE) within a communication system.

Common Connector Types

• RJ11, RJ12, RJ45: Typically used with UTP, STP, and other twisted pair data cables.
• AUI (Attachment Unit Interface), DB15: Used in the formation of star topologies with twisted pair cable, or for connecting transceivers.
• BNC (Bayonet Neill–Concelman): Used with thin coaxial cable, common in older Ethernet networks.
• Coaxial T-Connector: The standard method for connecting a station to a coaxial bus cable.
• DB25 and DB9: Serial connectors used for data transmissions.

Signal Adaptation Devices

Baluns and Transceivers: These devices adapt the signal, converting it between different media types such as Coaxial, Twinax, UTP, or dual coaxial, generally handling twisted pair cables, whether shielded or unshielded.

Network Infrastructure and Wiring Management

• Rack: A standardized cabinet used to organize and house network connections and equipment in an orderly manner.
• Patch Cords: Short cables used to extend or connect incoming and outgoing wires within a rack or patch panel.
• Ducts (Conduits): A metal or plastic structure attached to the floor or wall, used to house and protect all network wiring.
• Wall Plates and Rosettes: Connectors or outlets that are inserted into the ducts or attached to the wall, serving as the interface between the wall outlet and the network cable.

Optical Fiber Connectors

• SC Connector (Subscriber Connector): A direct insertion connector commonly used in general telecommunications and Gigabit Ethernet applications.