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Real-time Speech Communication on Packet Networks named an IEEE Milestone

In the 1970s and early 1980s, the Laboratory, working on its own and in collaboration with other research laboratories, conducted pioneering research, development, and experiments in the use of packet networks for speech communications. In August 1974, the first real-time packet speech, between Lincoln Laboratory and the University of California's Information Sciences Institute in Marina del Rey, California, used 8 kbps continuously variable slope delta modulation to digitize the speech, and traversed at least eight hops on the ARPANET (for Advanced Research Projects Agency Network). The first real-time linear predictive coding (LPC) communication over the ARPANET, with speech coded at 3.5 kbps, took place between Culler Harrison, Inc. (CHI) in Goleta, California, and the Laboratory in December 1974. In 1976, CHI, SRI in Palo Alto, California, and Lincoln Laboratory participated in the first real-time LPC conferencing over the ARPANET. And, in June 1982, a major achievement was realized: packet-speech conferencing over a wideband satellite network was demonstrated by linking voice terminals on local-area cable networks at Lincoln Laboratory, a mobile packet radio net at SRI, and the Information Sciences Institute, where a special interface provided connection to the regular switched telephone network.

Feb 03, 2012 12:00 AM

MIT Lincoln Laboratory News

MIT Lincoln Laboratory's role in this seminal R&D effort is honored