ALOHAnet
lorenetworking
The 1971 University of Hawaii radio network whose random-access scheme became the ancestor of Ethernet's collision handling.
Norman Abramson's team needed to link campuses across islands, so ALOHAnet let stations transmit whenever they had data and simply retransmit after collisions. That 'try, collide, back off' idea is the direct intellectual ancestor of Ethernet's CSMA/CD: Robert Metcalfe studied ALOHA closely before sketching Ethernet at Xerox PARC. Wireless networking, in a sense, came before wired LANs.