Obit One of the internet's founding fathers, ARPANET packet-switching pioneer Larry Roberts, has died aged 81.
Before ARPANET, telecommunications connections were carried over "circuit-switched" networks. A voice call, for example, used dedicated resources end-to-end, and the rudimentary data networking of systems such as Telex were handled the same way.
However, a number of academics proposed a different architecture for data transmission. Computers, they argued, could share their network connections and communicate by breaking data into discrete packets, addressing them to their destination, and letting the recipient reassemble the data.
That work was independently pioneered by Paul Baran in the USA and Donald Davies in the UK.
After studying electrical engineering at the Massachusetts Institute of Technology and completing his PhD, Roberts implemented a packet-switched link for his uni.
In 1966, he was appointed chief scientist for the Advanced Research Projects Agency – and put in charge of its embryonic ARPANET. He worked with packet-switching theorist Lawrence Kleinrock to create the project's first working network of four computers connected to each other in 1969.
In 2001, the National Academy of Engineers honoured Larry Roberts for his role as one of the Internet's founding fathers
As the BBC's obituary said, as well as helping design the early ARPANET, Roberts recruited engineers to build hardware and write software for the network.
Roberts himself noted on his personal site that he moved on from ARPANET in 1973 when the network had 23 computers connected to it, and founded a commercial packet-switching company called Telenet.
Telenet was an early adopter of the X.25 protocol, which remained in widespread use until it was mostly supplanted by the Internet Protocol.
After Telenet was acquired by GTE for $60m, Roberts concentrated on commercial ventures, spending 10 years as chairman and CEO of a company called NetExpress before founding three networking companies in succession: ATM Systems, Caspian Networks, and Anagran. He did not, however, capture his earlier successes, but Anagran was sold to Saisei Neworks in 2011.
He died on 26 December of a heart attack. ®