HISTORY OF DATA COMMUNICATION, STANDARDS ORGANIZATIONS FOR DATA COMMUNICATION.
Data communication can be defined as two personal computers connected through a Public Telecommunication Network (PTN). Point to point communication is the link between two stations A and B ie)., information is transferred between a main frame computer and a remote computer terminal.
A multipoint line configuration is one in which more than two specific devices share a single link. Morse code is used to send messages. A key which turned the carrier of a transmitter ON and OFF to produce the dots and dashes. These dots and dashes were detected at the receiver and it is converter back into letters and numbers makes the original message.
Forward Error Correction (FEC)
FEC, a receiver can use an error correcting code, which automatically correct certain errors without any retransmissions
In FEC, bits are added to the message before the transmission
Purpose of FEC code is to reduce the wasted time of retransmission
Data Communications History
• 1838: Samuel Morse & AlfredystemVeil Invent
• 1876: Alexander Graham Bell invented Tel
• 1910:Howard Krum developed Start/Stop Sy
History of Computing
• 1930: Development of ASCII Transmission Code
• 1945: Allied Governments develop the First Large Computer
• 1950: IBM releases its first computer IBM 710
• 1960: IBM releases the First Commercial Computer IBM 360
Main Contributors of Data Comm.
• Transmission Technology
• Packet Switching Technology
• Internet–1967:ARPANET by Advanced Research Project Agency (ARPA) of U.S.
–1975: TCP/IP protocol
• LAN Technology
–DIX-Ethernet & IEEE 802 Networks
• WAN–1976: ISO releases HDLC & CCITT releases X.25 (PSPDN)
The Applications Of Data Communication:
· Used in Automatic Teller Machine (ATM) Internet
· Airline and Hotel reservation system
· Mass media
· NEWS network
Advantages And Disadvantages Of Parallel Communication:
Parallel transmission is speed
Used for short distance communication
Require more lines between source and destination