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A HISTORY OF COMPUTER COMMUNICATIONS: 1968 -1988

TECHNOLOGIES

A technology begins with an idea and is reduced to practice with a working example, in our case, a product. The core technolgy of this historical reconstruction is packet switching. Packet switching began with an idea, one first conceived by Paul Baran and then a few years later by Donald Davies who gave the technology the name that would survive. Yet Baran would be the first to acknowledge that the sense of the idea dates back to the early days of semaphore technology or even earlier. The idea, elaborated by the contributions of many others, including Larry Roberts, Robert Kahn and Len Kleinrock, was finally reduced to a working prototype by roughly 1972: the Arpanet demonstration at the ICCC trade show. When the time came a few years later to better interconnect computers, Robert Metcalfe at Xerox PARC drew upon his Arpanet experiences and his understanding of the Alohanet technolgies and innovated Ethernet. Ethernet also took the contributions of others as well as many years to reduce to a working product and many more years to reduce to a cost-effective product. Ethernet becomes the leading technology of the then emerging Networking market. Concurrently, the network protocol of Arpanet had to be improved many times before the protocols of TCP/IP and the promise of OSI made possible the technologies and products of first Networking and then Internetworking.

While not explored in depth as is the trajectory of packet switching into Ethernet, technologies were needed to build high speed lease-line modems, technologies mastered early by Jerry Holsinger and G. David Forney both of Codex. Their accomplishments led to the Quadrature Amplitude Modulation (QAM) technology being made an international standard and to products that Codex leveraged into market leadership. Just as the ideas of Holsinger and Forney were first explored by a professor at a university, Robert Gallager of M.I.T., so was the innovation of statistical multiplexers by Wesley Chu of U.C.L.A. His ideas would be independently explored and reduced to practice by both Codex, under the leadership of Forney, and by Roger Evans and Bill Norred at Micom, a company on the verge of bankrupty until their statistical multiplexers, the Micro800 Data Concentrators, led to unexpected success and market leadership.