A Rule Tested Between Hawaiian Islands Changed How Shared Networks Speak
Tech From Here: Hawaiʻi, by RN Collins

Alt text, credits and the words on each frame (14 of 14 frames).

Frame 1 of 14: tfh-hi-c14-02-01.jpg
Alt text: A 1971 photograph of ALOHAnet equipment at the University of Hawaiʻi: a video terminal and the rack unit labeled ALOHA TCU, the terminal control unit, in a window office with Diamond Head behind. The operator at the left of the original is cropped out. It is the real network the cover names.
Credit: Photo: Norm Abramson/UH Mānoa
Words on the frame: A Rule Tested Between Hawaiian Islands Changed How Shared Networks Speak / Before Wi-Fi, ALOHAnet taught shared networks what to do when devices talked at once.
Source page: https://spectrum.ieee.org/alohanet-introduced-random-access-protocols-to-the-computing-world

Frame 2 of 14: tfh-hi-c14-02-02.jpg
Alt text: Illustrative photo: a 1973 photograph of an ALOHAnet user terminal with the ALOHA PCU, the programmable control unit, on a desk at the University of Hawaiʻi, Diamond Head behind. It shows the kind of equipment that shared the radio channel; the slide's question is about the channel, which no photograph shows.
Credit: Source: Abramson, IEEE ComMag 2009
Words on the frame: Who gets to speak when everyone shares the same channel?
Source page: https://www.eng.hawaii.edu/wp-content/uploads/2020/06/THE-ALOHANET-%E2%80%94-SURFING-FOR-WIRELESS-DATA.pdf

Frame 3 of 14: tfh-hi-c14-02-03.jpg
Alt text: Illustrative photo: the Hawaiian Islands seen from the International Space Station in January 2014, with Oʻahu, Molokaʻi, Maui and Hawaiʻi Island in view. It shows the islands the 1971 network connected; it does not show ALOHAnet equipment and is not from 1971.
Credit: Photo: NASA
Words on the frame: In 1971, ALOHAnet operated a UHF packet-radio network across Hawaiʻi.
Source page: https://commons.wikimedia.org/wiki/File:ISS-38_Hawaiian_Island_chain.jpg

Frame 4 of 14: tfh-hi-c14-02-04.jpg
Alt text: Illustrative photo: a 1970s Experimental Packet Radio rack (Rockwell radio unit and digital unit, Collins Radio) from DARPA's Packet Radio Program, on display at the Computer History Museum. It is ALOHAnet's descendant, not ALOHAnet itself; it stands for the radios that followed the transmit, wait for acknowledgment, retry rule.
Credit: Photo: Marcin Wichary, cropped
Words on the frame: Transmit. Listen for acknowledgment. If none arrives, wait a random interval, and try again.
Source page: https://commons.wikimedia.org/wiki/File:Terminal_Interface_Unit_(TIU)_and_Experimental_Packet_Radio_(EPR)_(2230480776).jpg

Frame 5 of 14: tfh-hi-c14-02-05.jpg
Alt text: Illustrative photo: a Hewlett-Packard 2100 minicomputer with tape drives and a printer, photographed at the European Southern Observatory in Chile in 1974. ALOHAnet's hub, the Menehune, was an HP 2100; this is the same model, not the Hawaiʻi machine, and it shows nothing about random delay.
Credit: Photo: ESO, cropped
Words on the frame: Random delay kept unsuccessful terminals from colliding again in lockstep.
Source page: https://commons.wikimedia.org/wiki/File:ESO_Hewlett_Packard_2100_minicomputer.jpg

Frame 6 of 14: tfh-hi-c14-02-06a.jpg
Alt text: Illustrative photo: the Wilfred J. Holmes Hall, College of Engineering sign at the University of Hawaiʻi at Mānoa, the building where the ALOHA System was developed. It stands for the research in the body text; it is a modern photograph and does not show the system or the 18.4 percent figure.
Credit: Source: ETHW (IEEE History Center)
Words on the frame: Under its idealized model, Pure ALOHA peaks near 18.4% of channel capacity. / The ALOHA System, in figures / Developed: 1970 through 1976 / Pure ALOHA peak: About 18.4 percent of channel capacity, under the idealized traffic model
Source page: https://ethw.org/File:Alohanet_plaque_Holmes_building.jpg

Frame 7 of 14: tfh-hi-c14-02-06b.jpg
Alt text: Black-and-white studio portrait of Franklin Kuo as a younger man in a dark jacket, white shirt and striped tie, photographed as a framed print on a grey wall. Kuo was a University of Hawaiʻi professor who codeveloped ALOHAnet, and his 1981 National Bureau of Standards survey is the source this frame cites. It shows the survey's author, not the survey or the network.
Credit: Photo: Masao Miyamoto, UH Archives
Words on the frame: Franklin Kuo’s 1981 National Bureau of Standards survey describes the network as an experimental radio computer-communication system developed from 1970 through 1976. / ARPA satellite node: December 1972
Source page: https://spectrum.ieee.org/codeveloper-of-ethernet-predecessor-dies

Frame 8 of 14: tfh-hi-c14-02-07a.jpg
Alt text: Illustrative photo: a rack of SRI International packet radio equipment from DARPA's packet radio program (a Gateway, a Packet Radio Ministation and a Terminal/Host Interface Unit), on display at the Computer History Museum. PRNET followed ALOHAnet; this stands for the later shared-medium networks the sentence names, not for ALOHAnet.
Credit: Photo: Marcin Wichary
Words on the frame: ALOHA influenced later shared-medium protocols.
Source page: https://commons.wikimedia.org/wiki/File:Army_Packet_Radio_Network_Protocol_Study_-_SRI,_November_1977.pdf

Frame 9 of 14: tfh-hi-c14-02-07b.jpg
Alt text: Illustrative photo: a 10BASE5 Ethernet transceiver (an AMP tap with a Cabletron ST-500 unit) clamped onto a yellow coaxial cable. It stands for Ethernet, which kept ALOHA's random-wait retry and added listening before sending; it is not the Xerox original and shows nothing about Wi-Fi.
Credit: Photo: Fernost
Words on the frame: It is a lineage, not a claim that ALOHAnet simply invented Wi-Fi.
Source page: https://commons.wikimedia.org/wiki/File:Yellowcable_mit_AMP_tranceiver_auf_AUI_P4510208.JPG

Frame 10 of 14: tfh-hi-c14-02-08.jpg
Alt text: The ALOHAnet satellite dish on the roof of Holmes Hall at the University of Hawaiʻi at Mānoa, with some of the College of Engineering team standing in front, in an undated photograph courtesy of Ram Chandran. It is the antenna for the satellite link the sentence describes, not a picture of the tariff.
Credit: Photo: courtesy Ram Chandran
Words on the frame: When it extended packet networking through satellite facilities, / the technical path ran into a pricing system still organized around voice service.
Source page: https://www.hawaii.edu/news/2020/10/13/alohanet-honored-as-engineering-milestone/

Frame 11 of 14: tfh-hi-c14-02-09.jpg
Alt text: The IEEE Milestone plaque for the demonstration of the ALOHA packet radio data network, 1971, installed at Holmes Hall, University of Hawaiʻi at Mānoa, photographed as an object. The milestone establishes the site and the method, the boundary this slide draws; it does not make Hawaiʻi the sole origin of the internet.
Credit: Source: ETHW (IEEE History Center)
Words on the frame: What We Actually Know / What we know: A working random-access packet-radio system. / What we do not know: That every later wireless standard is the same protocol.
Source page: https://ethw.org/File:ALOHAnet-Milestone.png

Frame 12 of 14: tfh-hi-c14-02-10a.jpg
Alt text: Illustrative photo: a public Wi-Fi sticker with the Wi-Fi icon on a lamp post in Vienna, Austria. It stands for the Wi-Fi icon in the sentence; it is not in Hawaiʻi and has no link to ALOHAnet.
Credit: Photo: Herzi Pinki
Words on the frame: Every Wi-Fi icon hides a shared-channel question Hawaiʻi helped make computable. / Read the full record. / Does a sender wait for permission, or just transmit?
Source page: https://commons.wikimedia.org/wiki/File:Wi-Fi_sign,_Spittelauer_Platz.jpg

Frame 13 of 14: tfh-hi-c14-02-10b.jpg
Alt text: Illustrative photo: the front of a white 5-port Edimax Fast Ethernet hub, a shared-medium network box, with a Power light, a COL (collision) light and numbered port lights. It stands for the question of what happens when two transmissions collide; it is a consumer product and not a record of any actual collision or of ALOHAnet.
Credit: Photo: George Shuklin
Words on the frame: What happens when two transmissions collide?
Source page: https://commons.wikimedia.org/wiki/File:Edimax_Ethernet_Hub.jpg

Frame 14 of 14: tfh-hi-c14-02-10c.jpg
Alt text: Illustrative photo: the front of an 8-port Netgear DS108 dual-speed Ethernet hub, with rows of small indicator lights marked Col (collision) and Utilization %, a built-in readout of how much of a shared channel is in use. It stands for the question of whether a throughput figure is measured or theoretical; it is a consumer product with no link to ALOHAnet or its 18.4 percent figure.
Credit: Photo: heimnetzwerke.net
Words on the frame: Is the throughput figure measured, or theoretical?
Source page: https://commons.wikimedia.org/wiki/File:Netgear_DS108_Hub.jpg
