Data communication refers to the transmission of data between two or more points or devices. It has evolved from manual methods like hand signals and smoke signals to modern electronic and computer-based systems. Early developments included radio, television, telephone networks, and satellite communication. More recent technologies that advanced data communication include Integrated Services Digital Network (ISDN), which transmitted analog signals over copper cables, and Asymmetric Digital Subscriber Line (ADSL), which enabled faster data transmission over copper telephone lines than conventional modems. Data communication continues to evolve with new transmission methods and networking technologies.

1. Assesment
History & Evolution of Data
Communication
A. Athharul Haq
AMP/HNDIT/F/2014/0087

2. DATA COMMUNICATION
Communication is the process of sharing a message. A conversation between two people is
an example of communication.
Data communication is the physical transfer of data (in bit or byte stream) over a point-to-point
or point-to-multipoint communication channel. Examples of such channels are copper
wires, optical fibres, wireless communication channels, storage media and computer buses.
Data communication can be called as Data transmission, digital transmission, or
digital communications.
HISTORY AND EVOLUTION OF DATA COMMUNCATION
Data communication has an ancient history. Communication methods are changing from
time to time. We can declare to show the development in 2 ways.
1.Manual communication
2.Electronic and computer based communication
MANUAL COMMUNICATION
These kind of communication made manually. Informations were sent one place to another
place not by electronic devices.
1. Hand signal commuication
2. Smoke and Fire
3. Signal Board
4. Magazines and Notices
5. Communicate via birds

3. 6. Books
7. Talking
8. Sounding signal
Ancient people used varuiety of ways to communicate with people like the
above that what we saw. Though much deficiency was found in this manual
communication. Some of these are
 Couldn’t communicate with the long distance people.
 It was always one duplex(one way) communication.
 Could not use for all situations
 Some people found harder to understand the signals correctly.
So there is a need of a development to make the people to understand. In case
there is a need turn for electronics system. Therefore the electronic and
computer based system was arisen.

4. ELECTRONIC AND COMPUTER BASED SYSTEM
1. Radio
 It will tranfering the data in a sound form for a long distance.
 This is a simplex type of communication method – One way
 The limited frequency module(FM) - 30 Mhz to 1 Ghz
2. Television
 It will tranfering the data in a sound and visual form for a long
distance.
 This is a complex type of communication method – One way
3. Telephone
 This is a point to point tele-communication
 This is a full duplex type of communication method – One way
4. Satellite
 Satellite communication is the branch of telecommunication which
establishes and communication using satellites across the globe.
 Its in a 35784Km(average) height
 Its tranfering frequency limit is – 20Ghz to 40 Ghz

5. 6. ISDN (Integrated services Digital Network)
 Its use to transmit analog signals by copper cable and some other
mediums.
ISDN has 2 channels
 Bearer channel (2B channels) – 64 Kb/s
 Delta channel (D channel) – 16 Kb/s
7. Asymmetric Digital Subscriber Line (ADSL)
 Asymmetric digital subscriber line (ADSL) is a type of digital subscriber
line (DSL) technology, a data communications technology that enables
faster data transmission over copper telephone lines than a conventional
voiceband modem can provide.
 In ADSL, download bandwidth is faster than upload bandwidth