Bell Telephone Laboratories, Inc. was founded in 1925 as the research and development (R&D) branch of the Bell System. Until the early 1990s, Bell Labs was owned and supported by AT&T, the Bell System's parent company, and by the Western Electric Company (WECo), the Bell System's manufacturing branch, which was owned by AT&T. WECo paid the salaries of Bell Labs personnel who developed new products that WECo manufactured; AT&T paid the salaries of Bell Labs personnel who performed research and systems engineering (R&SE). The Bell System's customers provided R&SE revenue via their monthly telephone bills, and Bell Labs systems engineers ensured that the United States had the world's best telephone system.
The research performed at Bell Labs was the world's best, especially between the 1940s and the 1970s. Over the years, many Bell Labs employees received prestigious awards in their fields, including a number of Nobel Prizes. During the three decades that followed the 1947 invention of the transistor at Bell Labs, scientists and engineers at Bell Labs contributed many other advances to the technologies that underlie digital communications and digital computing—electronics, magnetic and semiconductor memories, digital circuit design, and integrated circuits.
Although federal regulation precluded AT&T from participating in the commercial computer industry until the 1980s, Bell Labs personnel also contributed directly and significantly to computer architecture and software science—partly to find better ways to control telephone switching systems and partly through basic research. Bell Labs researchers contributed to digital design, automata theory , databases, operating systems, programming languages, coding, speech processing, and other fields of computer science.
Early Computing and Bell Labs
An early computer was built at Bell Labs in the late 1930s using electromechanical relays. This research project was a generalization of the special-purpose computers called markers that controlled telephone calls. Markers were used from the 1930s to the 1950s in the electro-mechanical telephone systems that were manufactured by WECo and operated by the Bell System's telephone companies. An even more significant contribution to computing came in the 1960s with a telephone switching system called the No. 1 Electronic Switching System (1E).
During the early 1960s, three significant commercial software systems were developed concurrently at different places in the United States: the first database (for airline reservations), the first operating system (for IBM's 7090 computer), and the first real-time process control software (at Bell Labs, for the 1E). Software similar to that found in the 1E thirty years ago still controls factories and operates automobile engines.
During the 1970s and 1980s, the Unix operating system was developed at Bell Labs. Even though AT&T could not sell computer products like operating systems, Unix became popular anyway because it was adopted at many universities.
In the early 1980s, the Bell System was broken up, with a dramatic effect on Bell Labs. Since Bell Labs (and WECo) remained with AT&T, a new R&D company called Bell Communications Research (Bellcore) was created for the seven new "Baby Bells" (Ameritech, Bell Atlantic, Bell South, Nynex, PacTel, Southwest Bell, and US West). Many Bell Labs personnel were transferred to Bellcore before Bellcore split from Bell Labs in 1984.
Afterward, the phone companies' R&SE revenue went to Bellcore, and R&D at Bell Labs (now supported fully by WECo) gradually became more product-oriented. In the 1990s Bellcore's seven owners sold their R&D company, now called Telcordia, and AT&T split up again. WECo was divested as a separate company, called Lucent, and since Bell Labs went with Lucent, AT&T formed a new internal R&D division, called AT&T Labs. Some Bell Labs personnel were transferred to AT&T Labs before that split occurred.
Now the remnants of Bell Labs are spread across three different companies, one of which still uses the Bell Labs name. Although all three companies still perform outstanding R&D, the golden age of Bell Labs research is over.
see also Shannon, Claude E.; Telecommunications; Transistors.
Richard A. Thompson
Brooks, John. Telephone: The First Hundred Years. New York: Harper & Row, 1976.
Thompson, Richard A. Telephone Switching Systems. Boston: Artech House, 2000.