From the Hawaiian aloha, meaning hello and goodbye. A protocol developed at the University of Hawaii in the early 1970s as an improvement on the pure Aloha protocol. Slotted Aloha improves contention management through the use of beaconing, in which a receiver transmits signals at precise intervals, indicating to each source when the channel is clear to send a frame of data. Slotted Aloha essentially advertises the availability of a time slot in a channel. See also Aloha, AlohaNet, channel, clear to send, and time slot.