Definition (1):
In a bounded medium, the signals are confined to the medium; they never leave it. The three most popular types of bounded medium are “twisted-pair” wires, coaxial cable, and fiber-optic cable.
Definition (2):
“Bounded media are physical cables that signals travel through on a narrow path.” Bounded media is also called guided media.
Guided media are built up of an external conductor (generally copper) wrapped in a non-conductive material made jacket. Guided media are excellent for in-lab communications as they provide high speeds, are low-cost, and more secure than unbounded media. A demerit of guided media is distance barriers; a person can only use guided media as far as s/he can afford cable, and connection may be prevented over longer distances because of attenuation.
The three most popular and common types of bounded media are briefly discussed below:
- Coaxial Cable: This is a widely used kind of transmission media. For instance, a TV cable is generally coaxial. It is named after two conductors running parallel to each other. The middle conductor in the cable is generally copper, which is generally either a solid wire or twisted, stranded copper.
- Twisted-Pair Cable: It is the most popular cable for networking. Twisted-pair cable is light-weight, inexpensive, easy to install, supports different networks, and data speed of up to 100 Mbps.
- Fiber-optic Cable: It is the most expensive cable among these three types and hard to install. But data transmission speed is very fast, no EMI interference, and low attenuation.