Since Alexander Graham Bell invented the telephone more than a century ago, telephone lines and cables have evolved with the changing types of telephones. Constantly trying to be faster and more efficient, phone cables carry electricity and data to and from the telephone with surprising speed. A variety of cable types made from different materials offer a range of services tailored to a person’s or business’s needs.
A Short History of Phone Cables
When the first telephones were created in 1877, telephone cables were used to literally connect two phones so that the people on both ends could speak to each other. The obvious problem with this set up was that people wanted to be able to talk to more than one person. The immediate solution was to construct a central interconnection facility that would be used to create connections between private telephones. Soon there was a network of telephone lines leading to each personal telephone, and the wiring became a nightmarish web of lines crisscrossing over towns.
Telephone operators and inventors became interested in developing telephone cables that could contain multiple telephone wires wrapped together inside a well-insulated and water-resistant cable. Soon, bound phone cables began to replace the spider web of telephone wires hanging over cities. Cables could be used to carry telephone lines across rivers and underground.
Telephone cable companies have improved the quality of call audio and the strength of the cables themselves by experimenting with a variety of insulation and types of cables. Coaxial cables developed during the 1940s allowed hundreds of conversations to be transmitted over just two coaxial cables. Today, experiments with asymmetrical digital subscriber lines (ADSL) allow telephones to send more than just conversations along the cable lines. Using ADSL can transmit the sounds of voices, downloadable data, and even video channels. With these new developments, the uses for phone cables continue to expand.
Types of Phone Cables
Whether a telephone cable is intended for private or public use, there are a number of options available. Each type provides benefits and disadvantages, and the best type really depends on the intended application of the telephone cable.
Many public schools and private businesses choose to employ unshielded twisted-wire cables to create their telephone networks. The main benefit of this type of wire is that it is the least expensive type of telephone cable, making it the perfect choice for publicly funded entities and new businesses. Despite the low cost, the types of unshielded twisted-wire cable can vary from low-grade to high-speed. The outer layer of telephone wire contains four strands of other wires that are paired together and twisted at various lengths. The twists in the wires help to reduce interference picked up by other nearby wires or electrical equipment.
A slight step up from unshielded twisted-wire cables is shielded twisted-pair cables. The interference problems that plague the unshielded wires are reduced with this type by wrapping the twisted-pairs in foil. In addition to the foil enclosing the twisted-pairs inside the outer cable shell, another layer of foil is tightly wrapped around the bundle of pairs as a whole. This double-wrapping drastically cuts down on any interference problems that could arise from other electrical objects near the cable wires. Many businesses that use multiple telephone lines in addition to keeping electronic equipment, such as computers, near the phones find shielded twisted-pair cables to be very effective.
However, the type of phone cable that best reduces interference is coaxial cable. Coaxial cables are created from a single copper wire surrounded by plastic insulation. The copper wire helps to quickly and clearly transmit voices and data, but it is the braided metal shield that is wrapped around the plastic insulation that provides the resistance to electrical interference. With very few materials wrapped together to create this telephone cable, coaxial cables are some of the strongest and most efficient types of transmitters, making them ideal for covering long distances and for creating a network that links many telephones together. However, coaxial cables are also notoriously difficult to install.
Similar to coaxial cables, fiber-optic cables are created by a core transmitter wrapped in insulation. Fiber-optic cables feature a glass core at the center that is used to transmit light signals. By transmitting voices and data through light signals rather than through electrical pulses, fiber-optic cables nearly remove the problem of electrical interference all together. In addition to solving the interference problem, fiber-optic cables also transmit data at an exceptionally fast pace. This capability makes fiber-optic cables a perfect choice for applications such as video conferencing where the speed of the transmission is crucial to the effectiveness of the presentation.
Many newer homes and private businesses prefer to use Cat 5 wires for their telephone cable needs. The benefit of Cat 5 cables is that it can be used to connect a variety of electronics together with a single cable. Like the twisted cables, Cat 5 uses four differently colored wires wrapped together to transmit voices and data. However, it is the universal nature of the wires that make it perfect for private homes. Users can connect their telephones, appliances, and electronic equipment such as computers and sound systems through Cat 5 cables.