LAN Definition | What Is Local Area Network | Computer Networks | CompTIA
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History of LAN
LAN began in the ether. Not the 19th century concept of a mysterious, invisible medium between the sun and the Earth that conducts light — that’s Aether;
however, it’s not far off to think about LAN and Aether in the same context.
Here’s a timeline that will tell you why:
1973: Birth of the Ethernet
Dr. Robert M. Metcalfe invented the Ethernet in 1973. His job was to network all the computers in a building to each other and to the world’s first Xerox laser printer. In
a memo, he named the networking method “Ethernet” because the huge coaxial cable that would connect the computers to each other reminded him of the Aether concept.
Metcalfe’s idea was informed by ARPANET — the original internet developed by the U.S. Department of Defense— and the ALOHAnet, which was a packet-switching wireless radio network for computers developed by the University of Hawaii.
The Ethernet allowed computers to send packets of data through a coaxial cable to communicate with each other and the printer. It employed a collision-detection scheme. If nodes in the network fired at the same time, causing a collision, the mainframe
wouldn’t respond and the nodes would then wait a random number of milliseconds to fire again.
1977: First commercial LAN
Four years later, Datapoint Corp. installed the first commercial LAN at Chase Manhattan Bank in New York. Unlike Metcalfe’s
Ethernet, Datapoint’s LAN used the Attached Resource Computer (ARC) network. While Ethernet employed collision-detection, ARC employed a token-passing scheme to avoid simultaneous transmissions by nodes. In other words, the nodes took turns
transmitting signals instead of relying on random retransmission. Other companies, such as IBM, adopted the token-passing scheme to battle Ethernet for LAN supremacy throughout the ‘80s.
1979: Ethernet available to the public
Metcalfe started 3Com to develop and sell Ethernet products.
1985: IEEE becomes the standard for LAN
Ethernet became the Institute of Electrical and Electronics Engineers’ (IEEE) standard for LAN.
1990: Ethernet wins over LAN
Ethernet had won the LAN battle, in part by switching to a twisted pair cable, which reduces crosstalk and electromagnetic induction. In other words, Ethernet was faster.
1991: Work begins on wireless LAN
The IEEE started working on wireless LAN (WLAN), which is based on the ALOHAnet prototype.
1997: Wi-Fi is born
IEEE released the 802.11 (Wi-Fi) standard.
Instead of collision-detection, Wi-Fi employs a wait-and-see carrier sense multiple access/collision avoidance (CSMA/CA) scheme. A Wi-Fi device listens to radio waves broadcast by the LAN for a random amount
of time, and when the network is idle, the device transmits a signal (frame). When the receiver gets the frame intact, it sends back an acknowledgement (ACK) to the sender. Wireless LANs (WLANs) and LANs can access the internet or
Instead of collision-detection, Wi-Fi employs a wait-and-see carrier sense multiple access/collision avoidance (CSMA/CA) scheme. A Wi-Fi device listens to radio waves broadcast by the LAN for a random amount of time, and when the network is idle, the device transmits a signal (frame). When the receiver gets the frame intact, it sends back an acknowledgement (ACK) to the sender. Wireless LANs (WLANs) and LANs can access the internet or wide area networks (WANs) through a gateway