ALOHA

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What Does ALOHA Mean?

ALOHA was a pioneering networking system developed at the University of Hawaii in 1971 as a first demonstration of wireless networks. It used a medium access method along with experimental UHF frequencies.

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ALOHA served as the basis for the development of Ethernet and Wi-Fi networking.

This term is also known as ALOHAnet.

Techopedia Explains ALOHA

The concept of ALOHA emerged when frequency assignments for communications between computers were not available for commercial applications.

The initial version of ALOHA used two different frequencies in a hub configuration. The hub machines were used to broadcast packets to all outbound channels and to different client machines. Upon receiving error-free data at the hubs, an acknowledgment packet was sent to the clients. If no acknowledgments were received, data packets were retransmitted after a selected time interval. This mechanism detected and corrected collisions when two clients attempted to send packets at the same time.

All client nodes in ALOHA communicate with the hub using the same frequency. The shared use of a single medium for client transmissions was critical. A mechanism was used for controlling packet sending, resending and collisions. This was called pure ALOHA, or random access channel, and served as the basis for the development of Ethernet and Wi-Fi networks. It also was used for the outgoing hub channel, allowing broadcast packets to be sent to all clients on a second shared frequency where each client recipient has its own address.

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Margaret Rouse
Editor

Margaret jest nagradzaną technical writerką, nauczycielką i wykładowczynią. Jest znana z tego, że potrafi w prostych słowach pzybliżyć złożone pojęcia techniczne słuchaczom ze świata biznesu. Od dwudziestu lat jej definicje pojęć z dziedziny IT są publikowane przez Que w encyklopedii terminów technologicznych, a także cytowane w artykułach ukazujących się w New York Times, w magazynie Time, USA Today, ZDNet, a także w magazynach PC i Discovery. Margaret dołączyła do zespołu Techopedii w roku 2011. Margaret lubi pomagać znaleźć wspólny język specjalistom ze świata biznesu i IT. W swojej pracy, jak sama mówi, buduje mosty między tymi dwiema domenami, w ten…