Lesson 1 Flashcards
Is the transfer of data or information between a source and a receiver.
Data Communication
Transmits the data.
Source
Receives the data.
Receiver
Are the exchange of data between two devices via some form of transmission medium such as a wire cable.
Data communications
Refers to information presented in whatever form is agreed upon by the parties creating and using the data.
Data
Information that is stored in digital form.
Data
Is defined as knowledge or intelligence
Information
Is a set of devices interconnected by media links
Network
A global computer network providing a variety of information and communication facilities, consisting of interconnected networks using standardized communication protocols.
Internet
In what year was a proposal submitted to a Scottish magazine that suggested running a communications line between villages?
1753
How many wires were the suggested communications line between villages from a proposal submitted to a Scottish magazine?
26 parallel wires
What did each wire represent in the proposal that was submitted to a Scottish magazine?
Letters of the Alphabet
Who developed an unusual system based on five-by-five matrix representing 25 letters?
Carl Friedrich Gauss
Why were there only 25 letters included in Gauss’s system?
I and J were combined
When did Gauss develop an unusual system based on a 5x5 matrix?
1833
The first successful and practical data communications system.
Telegraph
Who invented the Telegraph?
Samuel F.B. Morse
When was the Telegraph invented?
1832
What were transmitted across the wire of a telegraph?
dots and dashes
First practical data communications code.
Morse Code
When did Morse secure an American patent for his telegraph?
1840
What was the first telegraph line established?
“What hath God wrought!”
Places where the first telegraph line was established between
Baltimore and Washington D.C
When was the first telegraph line established?
1844
When was the first slow-speed telegraph printer invented?
1849
When did the first high-speed printers become available?
1860
Speed of the first high-speed printers.
15-bps
Allowed signals up to six different telegraph machines to be transmitted simultaneously over a single wire.
Telegraph Multiplexer
Who invented a telegraph multiplexer?
Emile Baudot
When was the telegraph multiplexer invented?
1874
Who invented the telephone?
Alexander Graham Bell
When was the telephone invented?
1876
Who succeeded in sending radio telegraph messages?
Guglielmo Marconi
When did Guglielmo Marconi succeeded in sending radio telegraph messages?
1899
What allowed the transmission of information across large spans of water?
Commercial radio stations
When were the first commercial radio stations installed?
1920
Who developed the first special-purpose computer using electromechanical relay?
Bell Laboratories
When was the first special-purpose computer using electromechanical relay developed?
1940
What was the first mass produced electronic computer?
UNIVAC
Who built the UNIVAC?
Remington Rand Corporation
When was the UNIVAC mass produced?
1951
When were batch processing systems replaced by on-line processing systems.
1960s
When were the microprocessor-controlled microcomputers introduced?
1970s
When did personal computers became an essential item?
1980s
When did the AT&T operating tariff allowed only equipment furnished by the same company to be connected to AT&T lines.
1968
When did the Internet began to evolve at the ARPA?
1969
Was formed to connect sites around the US.
ARPANET
When was ARPANET formed to connect sites around the US?
1970
What does ARPANET stand for?
Advanced Research Projects Agency Network
When did the World Wide Web became publicly available?
1991
3 major developments
reduced cost and size of terminals, new software systems, competition
Information can be ____ or ____.
Local or Remote
Communication that occurs face to face
Local Communication
Communication that occurs over a long distance
Remote Communication
Is any system of computers used to transmit and/or receive information between two or more locations.
Data Communication Network
Is a set of equipment, transmission media, and procedures that ensures that a specific sequence of events occurs in a network in the proper order to produce the intended results.
Network Architecture
Primary goal of network
to give the users of the network the tools necessary for setting up the network and performing data flow control.
General Classifications of network and network protocols
Current Networks, Legacy Networks, Legendary Networks
Include the most modern and sophisticated networks and protocols available.
Current Networks
Is the generic name assigned to any old network which is rarely used today.
Legacy Networks
Is called this when an antiquated network or protocol finally disasppears
Legendary Networks
Classifications of Computer Networks
Broadcast Network, Point-to-point Network
All stations and devices on the network share a single communication channel
Broadcast Network
It only has two stations and no addresses are needed.
Point-to-point Network
Are set if customs, rules, regulations dealing with formality or precedence.
Protocols
Are sets of rules governing the orderly exchange of data within the network or a portion of the
network.
Data Communication Protocols
Refers to the structure or format of the data within the message, which includes sequence in which
the data are sent.
Syntax
Refers to the meaning of each section of data
Semantics
Are guidelines that have been generally accepted by the data communication industry
Data Communications Standards
Data Communication Protocols can either be ____ or ____
Connection Oriented or Connectionless
Modified definition of Data Communication
“Data Communication is the exchange of data (in the form of 0’s and 1’s) between two devices (computers ) via some form of the transmission.”
