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Data Communication

Data Communication

Data communication refers to the movement of encoded information from one point to another by means of electronic transmission system. It can also be defined as the exchange of data between two devices via some form of transmission medium which can be wired or wireless. Another definition for data communications simply mean the transferring of digital information (usually in binary form) between two or more points (terminals). At both the source and destination, data are in digital form; however, during transmission, they can be in digital or analog form Information is carried by signal, which is a physical quantity that changes with time. The signal can be a voltage proportional to the amplitude of the voice like in simple telephone, a sequence of pulses of light in an optical fiber, or a radio-electric wave radiated by an antenna.
The fundamental purpose of data communication is to exchange information which is done by following certain rules and regulations called protocols and standards. Communications between devices are justified for the following reasons:
i. Reduces time and effort required to perform business task
ii. Captures business data at its source
iii. Centralizes control over business data
iv. Effect rapid dissemination of information
v. Reduces current and future cost of doing business
vi. Supports expansion of business capacity at reasonably incremental cost as the organization
vii. Supports organization’s objective in centralizing computer system
viii. Supports improved management control of an organization.

The effectiveness of a data communication system depends on three fundamental characteristics


The system must deliver data to the correct destination. Data must be received by the intended device or user and only by that device or user.


The system must deliver data accurately. Data that have been altered in transmission and left uncorrected are unusable.


The system must deliver data in a timely manner. Data delivered late are useless. In the case of video, audio and voice data, timely delivery means delivering data as they are produced, in the same order that they are produced, and without significant delay. This kind of delivery is called real-time transmission.