DATA COMMUNICATION PRINCIPLES Digital Data Digital Data consists

DATA COMMUNICATION PRINCIPLES : Digital Data

Digital Data consists of information whose values are chosen from a finite number of values. If the data vary as a function of time then time may advance either continuously or in steps. Examples of digital data are number of students enrolling every year and stock market shares sold during a certain day. In the former example, time varies in steps (of one year) while in the later the time varies continuously (throughout the day). Modern computers and networks process data only in digital form. If the user data is in analog form then it must be converted into an equivalent digital form before a computer can accept it. The process of converting analog data into digital form is called analog to digital (A/D) conversion. The reverse process is called D/A conversion - read as D to A conversion. The network transmission links have the ultimate responsibility of taking data from one point to another. Transmission occurs in the form of signals traveling from one point to another. A signal is a representation of data as a function of time (or other dependent variables 3).

REFERENCES • Ahmad A. - Data Communication Principles. For Fixed and Wireless Networks • Cornelius T. Leondes - Database and Data Communication Network Systems, Three-Volume Set_. . -Academic Press