The group of interconnected computers through transmission media in-order to communicate and share resources like hardware, data and software is known as communication media. It is a system for communication between networks. The computers in the network may be connected through cables,telephone-lines, beams etc.
Advantage of Computer Network
Disadvantages of Computer Network
There are two main types of communication channels. They are:
1. Guided or Bounded or Wired Communication Media
A transmission media where data signals are transmitted along a specific path through cable is known as Guided Transmission Media. It transfer data from one place to another with the help of wire. There are three types of cables used for wired network. They are:
The twisted pair cable consists of a pair of insulated copper wire twisted around each other. The number of twisted pair may 1, 2, 4 or more. The twisted pair cable is mostly used for connecting computers on the network.
The twisted pair cable comes into two categories:
Coaxial cable have wide bandwidth and noise immunity. These are widely used in long distance telephone lines. It's transmission speed is much higher than twisted pair cables.
Fiber optic cables are made up of plastic or glass fibers and gives high quality transmission of signal at a very high speed. Fiber optic cable transmission are not affected by electromagnetic interference.These can be used to communicate either analog or digital signals. These are most commonly used for point to point one way communication.
2. Unbounded or Unguided or Wireless Communication Media
The way to transfer data without the help of wire is called Unguided media.
Types of Unguided Media
A communication media is the path through which data, information and files transfers from one computer to other computer in the form of electromagnetic wave i.e. electric signals.
The main two communication media are as follows:
Guided transmission media is such a transmission media where signals are transmitted along a specific path through cable.
Any three guided transmission media are as follows:
Unguided transmission media is such a media where information is transmitted by sending electromagnetic signals through free space, as the signals are not guided in any specific direction or inside any specific medium.
Any three unguided transmission media are:
An optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements are typically individually coated with plastics layers and contained in a protective tube suitable for the environment where the cable will be deployed. The data travels at a very high speed in the form of light.
A type of wire that consists of a center wire surrounded by insulation and then a grounded shield of braided wire. The shield minimizes electrical and radio frequency interface. Coaxial cabling is the primary type of cabling used by the cable television industry and is also widely used in computer networks, such as Ethernet.
An UTP cable is one of the most popular LAN cables. This cable consists of 4 twisted pairs of metal wires(that means there are 8 wires in the cable). RJ45 connectors are used in UTP cables.
The most powerful computer on the network, which does all the processing for the user is known as host computer.
Terminal is a specialized network device on a host-based network that transmits the data entered by the user to the host for processing and displays the results.