The packet radio network at the University of Hawaii that began operating in 1971 was ALOHAnet.
Developed under Norman Abramson and colleagues, ALOHAnet was designed to connect users on the Hawaiian islands with a central time-sharing computer at the University of Hawaii. Its first packet-broadcasting unit went into operation in June 1971, making it an important early example of wireless packet data networking.
The system used radio channels rather than telephone lines. Remote terminals transmitted packets to a central hub, which acknowledged successful deliveries. If an acknowledgement did not arrive, a station waited for a random interval and retransmitted. This approach addressed the central difficulty of many independent users sharing one radio channel: collisions.
ALOHAnet’s Pure ALOHA method allowed stations to transmit whenever they had data, while the later Slotted ALOHA design restricted transmissions to timed slots and improved efficiency. The ideas influenced Ethernet’s contention methods and later wireless systems, including Wi-Fi and cellular signaling. A common mix-up is treating ALOHA as only a protocol; ALOHAnet was the University of Hawaii network, while ALOHA also names the access techniques it pioneered.