Question

What’s the difference between fiber optic cable, twisted pair cable and coaxial cable?

Answer 1

Twisted pair cable consists of a pair of insulated wires twisted together, which is adapted in the field of telecommunication for a long time. With the cable twisting together, it helps to reduce noise from outside sources and crosstalk on multi-pair cables. Basically, twisted pair cable can be divided into two types: unshielded twisted-pair (UTP) and shielded twisted-pair (STP). The former serves as the most commonly used one with merely two insulated wires twisted together. Any data communication cables and normal telephone cables belong to this category. However, shielded twisted pair distinguishes itself from UTP in that it consists of a foil jacket which helps to prevent crosstalk and noise from outside source. It is typically used to eliminate inductive and capacitive coupling, so it can be applied between equipment, racks and buildings. There exist following several different types of 




Coaxial cable acts as a high-frequency transmission cable which contains a single solid-copper core. A coaxial cable has over 80 times the transmission capability of the twisted-pair. It is commonly used to deliver television signals and to connect computers in a network as well, so people may get more familiar with this kind of cable. There are two coaxial cables: 75 Ohm and 50 Ohm.

omputing and data communications are fast-moving technologies. There comes a new generation of transmission media—fiber optic cable. It refers to the complete assembly of fibers, which contain one or more optical fibers that are used to transmit data. Each of the optical fiber elements is individually coated by plastic layers and contained in a protective tube. Fiber optic cable transmits data as pulses of light go through tiny tubes of glass, the transmission capacity of which is 26,000 times higher than that of twisted-pair cable. When comparing with coaxial cables, fiber optic cables are lighter and reliable for transmitting data. They transmit information using beams of light at light speed rather than pulses of electricity.

Nowadays, two types of fiber optic cables are widely adopted in the field of data transfer—single-mode fiber optic cables and multimode fiber optic cables. A single-mode optical fiber is a fiber that has a small core, and only allows one mode of light to propagate at a time. So it is generally adapted to high speed, long-distance applications. While a multimode optical fiber is a type of optical fiber with a core diameter larger than the wavelength of light transmitted and it is designed to carry multiple light rays, or modes at the same time. It is mostly used for communication over short distances because of its high capacity and reliability, serving as a backbone applications in buildings.