Communication Technology applied in Computer Network
During the 20th century the most demanding technology has been information collecting, processing, and distribution. Organizations with hundreds of offices spread over a wide geographical area are to be interconnected with computers for efficient gathering, processing, and distribution of information. This cannot be achieved by the old idea of a single computer. Interconnected computers do this job by a system. This system is known as a computer network and physical interconnecting technology is called networking technology. We discuss about Communication Technology applied in Computer Network.
“It is an interconnected collection of autonomous computers or system of computers capable of sharing resources and controlling services.” The network must be efficient, reliable, and economic. The common resources are to be shared by the system whenever needed, including data, peripheral devices like hard disk storage, printer, fax, etc.
Many organizations use separate PCs in operation. Each computer uses a separate printer, separate program software, and other essential resources. For example, a company has many departments, and two or more sister organizations have a computer in each department. They may have similar software and common data file.
a system that will provide communication, exchange of information access to any file, and sharing software so that the system will work efficiently, reliably, and economically. All these requirements can be achieved using networking only. The main goals of networking are-
- Network provides resource sharing.
- It provides high reliability by using another machine.
- Access to any file and data.
- Finally, the system is saving money by the network only.
NETWORKS IN COMMUNICATIONS
Now let us discuss communication links that can be established for many to many communications a link between many PC connected in a laboratory, telephone PBX, cable network, etc. To provide this interconnection for many to many, certain techniques are used known as Networks.
A network is an interconnected system that provides communication links among two or more stations each station in a network is known as a node. The following figure shows a simple communications network with each node relates to the other.
Communication Technology applied in Computer Network so, there are many electronic communication networks, which can be broadly classified according to their coverage area and their facilities provision, these are-
WAN (Wide Area Network)
As the name amplifies, the coverage area is very wide, and stations are very high in number, hence named WAN (wide area network). A very common example is the national television system, cellular mobile phones, etc. WAN is a wide network that can cover the whole country or state for communications. In WAN, the link may be established by using cables, microwave towers, or maybe a satellite link or it can be a combination of two or more links.
MAN (Metropolitan Area Network)
A network like WAN and bigger than LAN is also established hence known as MAN it is a medium-sized network. An example of MAN is a cable network within a city. The cable network is receiving TV programs from the satellite and it connects many (users). TV sets in the network to watch these programs by such a network containing so many nodes located at different locations in the network. The communication link is through a cable and one-way but it is a network known as Metropolitan Area Network.
LAN (Local Area Network)
The third and simplest network is the local area network widely used in computer communications. When several computers close to each other within kilometer radiuses are to be interconnected. LAN is the common network suitable for efficient computer communications. LAN contains 10 to 1000 PCs interconnected in an organization with common control & storage. A computer laboratory in a college mostly uses LAN for training the students. A LAN system consists of many PC terminals, but a common control terminal is controlling this network known as a server.
These are the set of rules or standards designed to enable computers to be connected and transfer information through a network. when the network is too big for communication, we will understand the standard method of communication and physical interconnections should be established. when computers in different countries are to be connected then there must be different standards of different nations. it becomes very complex communication. this problem can be solved by making common rules to inner connect and communicate between computers are known as protocols, all the entities in the network must agree on these protocols. In such a network data is transmitted in a form of packets on the network. the packets contain standard format. The format is designed by the type of protocols. The format of the packet in a type of protocol specifies the following information such as :-
Header (start of package):
It specifies the source and destination address.
This part of the packet contains actual data or information. The information coding is also decided by protocol standards. example data, nibbles, in bytes, ASCII, EBCDIC, etc.
In this part of the package, ending information is transmitted like error checking and correction information. when this packet is transmitted during the transmission message may be damaged or loosed due to serious reasons, for this purpose this information is sent in the trailer part.
There is different international standard protocol at different level.
- TCP/IP (Transmission Control Protocol and Internet Protocol)
- UDP (User Datagram Protocol)
- ARP (Address Resolution Protocol)
- ICMP (Internet Control Message Protocol)