Those with an eye to the historical context may notice something familiar about the current concerns and enthusiasm for Wi-Fi. Though we are all told that wireless internet is the big, new thing, it is actually far from new. In fact, packet-based wireless networking is where the internet came from.
In 1970, Arpanet, the network that would grow to become the global internet, had just four nodes - three in California and one in Utah. The four hosts communicated over slow dial-up lines via Honeywell-produced interfaces using a special-purpose communication protocol. There was Telnet and FTP, but that was all: the world wide web was a long way off.
But in Hawaii an exciting network scheme was being created by a surfing enthusiast who had moved to the islands from Stanford University in California to pursue better waves and a technology challenge. Norm Abramson had been asked to implement a network between the University of Hawaii sites on the islands. He realised that phone lines were too unreliable and stringing a series of new connections was technically unfeasible and prohibitively expensive. The solution was the first wireless computer network.
The Aloha network transmitted data in fixed-size packets. Each of the nodes checked whether the radio channel was in use before attempting to transmit data; collisions between packets would cause the transmitting node to wait before re-attempting the transmission. It was simple, powerful and, in July 1970, it went live.
The result of Aloha over the next few years was dramatic. A failing Harvard graduate student, Bob Metcalfe, moved to Xerox Parc in California and decided to play with the Aloha protocols. Rather than transmit packets over a radio channel, Metcalfe used a cable. The result was the invention of Ethernet, the creation of 3Com, and the wiring of a million offices with inexpensive LAN technology.
Aloha also encouraged the development of a packet-switched radio network called PRNET, developed by one of the founders of Arpanet to provide secure military communications. PRNET evolved to become the basis for the modern GPRS. In 1972, Abramson persuaded the Arpa management to provide a network link to the mainland so that Aloha could be linked to Arpanet.
Arpanet linked dedicated nodes but could not address individual host computers behind those nodes, while PRNET required an end-to-end protocol that would allow reliable communication. The designers, Bob Kahn and Vinton Cerf, realised the same protocol could be used for both, allowing "inter-networking": TCP was born and evolved into TCP/IP. The first full-scale demonstration was in 1977 - a reliable packet communication via satellite and cross-country telephone cables.
The internet evolved out of the solutions to specific technological problems faced by the developers of wireless networks. Wi-Fi may require some difficult security problems to be addressed, but it is somehow fitting that the wheel has come full circle.
