Data Communication/ Data Transmission Channels
A Data Communication Channel/ Data Transmission Channel is a medium, or pathway through which data are transmitted between devices.
It falls into three basic types:
1. Wire Cable
It is the most common type of data communication channel in use today. It includes telegraph lines, telephone lines, and coaxial cables. Telegraph lines and telephone lines consist of a pair of wires; each wrapped in a protective coating and twisted around the other. While, coaxial cable consists of a single wire surrounded by a layer of insulating material and then by a metal sheath or tube for protection. Television cable is one of the examples of coaxial cables.
There are two categories of coaxial cables:
a. Baseband coaxial cables
It carries a single digital signal at a rate between 1 million and 50 million bits per second.
b. Broadband coaxial cables
It carries multiple analog signals together at speeds between 20 million and 50 million bits per second.
Wire cable channels is standardized to transmit data, therefore, it reduces compatibility problems.
Data are transmitted by microwave signals through the atmosphere rather than through wire cables, in the same ways as radio and television signals are transmitted. However, microwave signals must be transmitted in straight lines because they cannot bend around corners.
3. Fiber Optic
Unlike wire cable and microwave, a fiber optic channel transmits in digital form. It uses light impulses that travel through clear, flexible tubing. The tubing is thinner than a human hair. It can transmit data at very high speeds with few or no errors.