The History of Ethernet

Robert Metcalfe and the Invention of Local Area Networks

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“I came to work one day at MIT and the computer had been stolen so I called DEC to break the news to them that this $30,000 computer that they'd lent me was gone. They thought this was the greatest thing that ever happened because it turns out I had in my possession the first computer small enough to be stolen!” (Robert Metcalfe)

The Ethernet is a system for connecting computers within a building using hardware running from machine to machine. It differs from the Internet, which connects remotely located computers. Ethernet uses some software borrowed from Internet protocol, but the connecting hardware was the basis of a patent involving newly designed chips and wiring. The patent describes Ethernet as a "multipoint data communication system with collision detection."

Robert Metcalfe and Ethernet 

Robert Metcalfe was a member of the research staff at Xerox at their Palo Alto Ranch Center, where some of the first personal computers were made. Metcalfe was asked to build a networking system for PARC's computers. Xerox's wanted this set up because they were also building the world's first laser printer and they wanted all PARC's computers to be able to work with this printer.

Metcalfe met with two challenges. The network had to be fast enough to drive the very fast new laser printer. It also had to connect hundreds of computers within the same building. This had never been an issue before. Most companies had one, two or maybe three computers in operation at any one of their premises.

Metcalfe remembered hearing about a network called ALOHA that was used at the University of Hawaii. It relied on radio waves in lieu of telephone wire to send and receive data. This led to his idea to use coaxial cables rather than radio waves to limit interference in transmissions. 

The press has often stated that Ethernet was invented on May 22, 1973 when Metcalfe wrote a memo to his bosses touting its potential. But Metcalfe claims Ethernet was actually invented very gradually over a period of several years. As part of this lengthy process, Metcalfe and his assistant David Boggs published a paper titled, Ethernet: Distributed Packet-Switching for Local Computer Networks in 1976. 

The Ethernet patent is U.S. patent #4,063,220, awarded in 1975. Metcalfe completed creation of an open Ethernet standard in 1980, which became an IEEE industry standard by 1985. Today, Ethernet is considered the genius invention that means we no longer have to dial up to access the Internet.

Robert Metcalfe Today 

Robert Metcalfe left Xerox in 1979 to promote the use of personal computers and local area networks. He successfully convinced the Digital Equipment, Intel and Xerox corporations to work together to promote Ethernet as a standard. He succeeded as Ethernet is now the most widely-installed LAN protocol and an international computer industry standard. 

Metcalfe founded 3Com in 1979. He accepted a position as Professor of Innovation and Murchison Fellow of Free Enterprise at the University of Texas' Cockrell School of Engineering in 2010. 

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Bellis, Mary. "The History of Ethernet." ThoughtCo, Aug. 27, 2020, Bellis, Mary. (2020, August 27). The History of Ethernet. Retrieved from Bellis, Mary. "The History of Ethernet." ThoughtCo. (accessed March 22, 2023).