Data Communications Flashcards
Is the process of sending digital information (usually in binary form) between two or more points
Data Communications
Is the movement of encoded information by means of communication techniques
Data Communications
it is the information that is stored in digital form (i.e information that has been processed, organized and stored).
Data
Advantages of Digital Signals
easier to multiplex
easier to integrate into a switching system
easier to interface with other digital equipment
better noise immunity
better performance
easier to encode, decode, encrypt and scramble
Disadvantages of Digital Signals
Have a Larger Bandwidth
Require Synchronization
Additional equipment
Not commonly compatible with existing equipment
Require ADC/DAC
Restricted in wired topology
Signals, whether Voice , Video, or Binary , transmitted directly over a Cable are known as
Baseband Signals
Signals that involve a modulated carrier are known as
Broadband Signals
In 1832, He developed the first successful and practical data communication systems known as the TELEGRAPH
Samuel Morse
In 1833, He Developed an unusual system based on a five-by-five matrix representing 25 letters. The idea was to send message over a single wire
Carl Friedrich Gauss
In 1844 , First telegraph line was established between Baltimore and Washington D.C, the first message is
What hath God wrought!
In 1874, She invented the telegraph multiplexer which allowed up to six different telegraph machines to be transmitted simultaneously over a single wire.
Emily Baudot
In the 1930, a German engineer , demonstrated a computing machine.
Konrad Zuis
In 1940, Company is given the credit for the first special purpose computer using electromechanical relays for performing logical operations
Bell telephone
In 1946 , both developed the ENIAC computer
John Adam Presper Eckert and John Mauchley
In 1949, they developed the first all-electronic diode-based computer capable of executing stored programs
US National Bureau of Standards
In 1951, _____ computer was built by Remington Rand Corporation and was the first mass-produced electronic computer
UNIVAC Computer
In 1970, ______ microcomputers were introduced
microprocessor-controlled microcomputers
It creates set of rules and standards for graphics , document exchange, and provides models for equipment and system compatibility , quality enhancement , improved productivity, and reduced cost.
ISO
(International Organiztion for Standardization)
formerly known as the Consultative Committee for International Telephony and Telegraphy (CCITT) , is now the standards organization for United Nations to develop the recommended set of rules for telephone and data communications
ITU-T
International Telecommunication Union - Telecommunication
ITU-T developed __ Series for modem interfacing and data transmission over telephone lines
V Series
ITU-T developed __ Series for data transmission over public digital networks, e-mail and directory services
X Series
ITU-T developed __ and __ Series for ISDN and Broadband ISDN (Information Superhighway)
I and Q Series
Three Sectors of ITU
ITU-T (Telecommunications Sector)
ITU-R (Radio Communication Sector)
ITU-D (Development Sector)
it is the world’s largest professional society, which was founded in the United States and is comprised of electronics, computer and communications engineers
IEEE (Institute of Electrical and Electronics Engineers)
