Introduction to information and communication system

Introduction to information and communication system 

Information:

The processed data or some data which is useful, conveying some message and sense that is called information.

Types of information:

• Constructional/creative information
• Operational information
• Communication information

 

Constructional/creative information

This includes all information that is used for the purpose of producing something. Before anything can be made, the originator mobilizes his intelligence, his supply of ideas, his know-how, and his inventiveness to encode his concept in a suitable way.

There are many types e.g. technical drawings for the construction of a machine, a cake recipe, details of the chemical processes, an electrical circuit diagram, or the genetic information required for the construction of a living cell.

 

Operational information

All concepts having the purpose of maintaining some “industry” in the widest sense of the word are included under this kind of information. Many systems require operational information in the form of programs for proper functioning.

E.g. the operating system of a computer (e.g., DOS programs), the program controlling a robot or a process computer, warning systems for airplanes and ships.

Operational information in the animal kingdom, which we call “instincts” because of our lack of knowledge about their codes and methods of transfer.

 

Communication information

This is composed of all other kinds of information, e.g., letters, books, phone calls, radio transmissions, bird songs, and the message of the Holy Scriptural book.

These information does not include the construction of a product, neither is it involved in maintaining some process

The goals are transmission of a message, spreading joy, amusement, instruction, and personal confidences

 

Analog and Digital Information

The term analog is used to refer to the natural world, where time is continuous and most parameters(like light, sound Intensity, position etc.) can vary smoothly and continuously over some range, taking on an infinite number of possible values. The term digital is used to refer to information representations for which both time and the value being measured move in discrete steps i.e. when there are a finite number of possible values.

 

The Natural World is Analog
Human speech is an example of analog communication.
Speech causes to vibrate with varying amplitude (volume) and frequency (pitch).

 

The computer World is Digital

·        Digital computers communicate using 2 discrete values. In other words, they speak in binary (0 and 1).

·        Of course, 0s and 1s are not literally transmitted

·        In an electrical network, variations in voltage represent one of the two values.

·        In an optical network, pulses of light provide the discrete values.

·        The pulses of light or voltage variations are the “signal”.

·        Two values in different combinations sufficiently encode text, number, image and sound.

·        Recall that the telegraph was an early example of communications using discrete, electrical pulse transmission.

 

Information system:

A combination of hardware, software, infrastructure and trained personnel organized to facilitate planning, control, coordinate and decision making in an organization.

 

Communication Modes:-
It refers to the direction of flow of signals among linked devices.
There are three ways for transmitting data from one point to another
1. Simplex Mode
2. Half-Duplex Mode
3. Full-Duplex Mode

 

1. Simplex Mode:

•      Features:

a)     Unidirectional

b)    Send-only or Receive-only devices

c)     Sender is unaware about the status of transmission.

d)    Rarely used for data communication.

Example: Radio and T.V transmissions

 

2. Half-Duplex Mode

•      Features:

a)     Two-way communication but not simultaneously.

b)    At a moment it is unidirectional only.

c)     Can alternately send and receive data.

d)    Transmission direction can be changed  whenever required.

e)     Delay factor (Line Tumaround Time) is associated.\

Example:

1) Wireless handsets used by military personnel.

2) Internet browsing

3. Full-Duplex Mode:

•      Features:

a)     Also known as Duplex Mode

b)    Communication in both directions simultaneously.

c)     Line Tumaround time is eliminated.

d)    Much efficient mode

Example: Telephone communication system