Ever since the first telegraph in the 1820s and the invention of the phone in 1876, copper was found almost everywhere there was a communication cable. That’s quickly changing as fiber optic becomes more widespread. But, even now we still rely on copper cabling because of its many excellent qualities and lower cost.

Although relatively heavy, it has the highest electrical conductance of all non-precious metals and a very high tensile strength making it resist breaking when bent or stretched.

It is also highly ductile so can be drawn down to very thin diameters making it excellent for braided wiring and cables with multiple signal paths. This combination makes it ideal for electrical wiring as it easily twisted and bent at connections and terminations.

Other advantages are that it resists corrosion, which can reduce conductivity and does not expand when hot as much as other conductors do, like aluminum.

Communications Cables

Unshielded twisted pair (UTP) is the standard telephone cable and has become the most common computer networking cable as well. It consists of a pair of copper wires that form a loop with current running in each direction. Electrical interference can be cancelled out by twisting them together.

There are various categories of UTP as defined by the standards of the Telecommunications Industry Association (TIA) or International Organization for Standardization (ISO).

Category 3 (Cat3) is the standard telephone cable and was first used for Ethernet in the early 1990s with a top speed of 10 Mbps.

Next, was Cat5 introduced at the turn of the century. It is suitable for 10BASE-T, 100BASE-T or 1000BASE-T (Gigabit) standard for data transmission and is rated for a maximum frequency of 100 MHz. While it is still commonly used for local area networks, it has been superseded by Cat 5e.

Cat 5e improves on Cat5 by reducing cross-talk, which is where signal leaks from one wire to another. It is still limited to 100 MHz but is properly certified for Gigabit speeds.

At 250 MHz, Category 6 cable has more than double the bandwidth of Cat5, and is suitable for up to 10-gigabit Ethernet but is limited to lengths of 100 metres. Cat6A is the latest standard and doubles the bandwidth to 500 MHz.

Coaxial Cable

This type of cable usually consists of a single copper wire surrounded with a braided or foil shielding sometimes made of aluminum. Between the two conductors is a dialectric that insulates and protects the inner wire.

Cable companies use this type to bring TV signals and Internet service to the home, although they were originally used with mainframe computers and the first local area networks. The RG-6 standard of coaxial cable is quad-shielded and can carry a large number of signals at once.

Structured Wiring

To maximize the capabilities of all these types of copper wire in the premises they need to be installed in an optimal manner often referred to as structured wiring. There may be multiple computers communicating with each other and accessing the Internet. These would need to be connected together using a central hub or media panel that would serve as the portal to the Internet.

Coaxial cabling for cable TV or satellite can also be distributed through this central panel. Although video signals can be sent on Cat5 and coax, media hubs that serve video and audio may also be connected via one of several video copper cable standards.