Tuesday, 21 February 2012

Basic Elements Of Communication System




Basic Elements of a Communication System -


The following are the basic requirements for working of a communication system.


  1. A sender (source) which creates the message to be transmitted.
  2. A medium that carries the message.
  3. A receiver (sink) which receives the message.


In data communication four basic terms are frequently used. They are -

Data: A collection of facts in raw forms that become information after processing.
Signals: Electric or electromagnetic encoding of data.
Signaling: Propagation of signals across a communication medium.
Transmission: Communication of data achieved by the processing of signals.



Data Communication



DATA COMMUNICATION

We all are acquainted with some sorts of communication in our day to day life. For communication of information and messages we use telephone and postal communication systems. Similarly data and information from one computer system can be transmitted to other systems across geographical areas. Thus data transmission is the movement of information using some standard methods. These methods include electrical signals carried along a conductor, optical signals along an optical fibers and electromagnetic areas.

Suppose a manager has to write several letters to various clients. First he has to use his PC and Word Processing package to prepare his letter. If the PC is connected to all the client's PCs through networking, he can send the letters to all the clients within minutes. Thus irrespective of geographical areas, if PCs are connected through communication channel, the data and information, computer files and any other program can be transmitted to other computer systems within seconds. The modern form of communication like e-mail and Internet is possible only because of computer networking.


Thursday, 16 February 2012

High Level Languages. Its Advantages & Disadvantages



HIGH LEVEL LANGUAGES

Higher level languages are simple languages that use English and mathematical symbols like +, -, %, / etc. for its program construction.

Higher level languages are problem-oriented languages because the instructions are suitable for solving a particular problem. For example COBOL (Common Business Oriented Language) is mostly suitable for business oriented language where there is very little processing and huge output. There are mathematical oriented languages like FORTRAN (Formula Translation) and BASIC (Beginners All-purpose Symbolic Instruction Code) where very large processing is required.


Advantages of High Level Languages
Higher level languages have a major advantage over machine and assembly languages that higher level languages are easy to learn and use. It is because that they are similar to the languages used by us in our day to day life.