Comms 2 (Mod 1 & 2) Flashcards
Who defined data communication?
Lexicographers
“Any process that permits the passage from a sender to one or more receivers of information of any nature, delivered in any easy to use form by any electromagnetic system.”
Data Communication
data communication has its earliest roots in
Samuel Morse’s 1837 exhibition of a telegraph system
the telegraph, dots and dashes are transmitted across a wire through
Electromechanical induction
By this year, telegraph service had become adopted by the Great Western Railway, an endorsement that allowed the service to expand across the nation.
1843
Originally, the first telegraph was invented by
Sir Charles Wheatstone and Sir William Cooke
He secured an American patent for the telegraph
Samuel Morse
The first telegraph line was established between
Baltimore and Washington, D.C.
When did Morse secure an American patent for the telegraph
1840
The first slow-speed telegraph printer was invented in
1849
When was high-speed (15 bps) printers were available?
1860
It was formed for the purpose of carrying coded messages from one person to another.
Western Union Telegraph Company
Where was Western Union Telegraph Company located
Rochester, New York
Inventor of the telegraph multiplexer, which allowed signals from up to 6 telegraphs over a single wire.
Emile Baudot
Who made the first telephone call and when
Alexander Graham (June 1876)
Inventor of Telephone
Alexander Graham Bell
He succeeded in sending radiotelegraph messages.
Guglielmo Marconi
First Intelligible words spoken over the telephon
”Mr. Watson — Come here — I want to see you”
the first commercial radio stations were installed this year
1920
This computer was the first mass-produced electronic computer.
UNIVAC
Who built the UNIVAC
Remington Rand Corporation
The Baudot has 3 main parts hardware
- Keyboard
- Distributor
- Paper Tape
It replaced the punch card
UNIVAC
How many decimal digits/sec the UNIVAC can read
7200
It defines the direction of the flow of information between two communication devices; it tells the direction of signal flow between the two devices.
Transmission Modes
In Communication Networks, Communication can take place in one direction connected to such a circuit are either a send only or receive only device.
simplex
This system can transmit data in both directions, but only in one direction at a time
Half duplex
This system can transmit data simultaneously in both directions on transmission path.
full duplex
Types of coding
- Human Code
- Machine Code
Types of human code
- Morse code
- Dot and dash
Types of machine code
- Binary states
- binary digit
- byte
The word telegraph is derived from the Greek words
tele = “distant” graphein = “to write”
