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Friday, June 11, 2021

Bell Labs: discoveries and innovative technologies

© Mark Ollig


Founded in 1925, Bell Telephone Laboratories Inc., better known as Bell Labs, was AT&T’s (American Telephone and Telegraph) primary research and development department.

Scientists and researchers at Bell Labs invented thousands of technologies and devices, and obtained more than 26,000 patents.

Let’s take a look back at some of them.

From 1920 to 1923, scientists at Bell Labs designed the telephotography machine (think facsimile/fax machine).

May 19, 1924, this analog facsimile machine, manufactured at AT&T’s subdivision, Western Electric, transmitted one photograph 500 miles over telephone wires from a Cleveland sending station to a New York City receiving station in 4.5 minutes.

Bell Labs began using the telephotography machine for transmitting photographs to newspaper outlets over AT&T’s long-distance telephone network.

In March 1925, Picture Telegraphy (telephotography machine) transmitted photographs of President Calvin Coolidge’s second inauguration photos from Washington, DC, to San Francisco, Chicago, and New York over the AT&T telephone network.

April 7, 1927, Bell Labs publicly demonstrated the first long-distance live television transmission over telephone lines of Secretary of Commerce Herbert Hoover from Washington, DC to New York City.

“I am glad to welcome television as the latest product of scientific discovery,” Hoover said during the demonstration. “It promises that where the voice has led the way over the telephone wires, the eye will ultimately follow.”

Hoover would serve as US president from 1929 to 1933.

In 1929, at Bell Labs, Herman Affel and Lloyd Espenschied invented coaxial cable, opening the door for making it possible to carry thousands of simultaneous telephone calls over AT&T long-distance circuits.

In 1941, AT&T placed 200 miles of coaxial cable within an operational telephone network between Minneapolis, MN, and Stevens Point, WI.

By July 1950, there were 100,000 TV sets in the Minneapolis-St. Paul (Twin Cities) Minnesota viewing area.

Television broadcasting using coaxial cable arrived in the Twin Cities area Sept. 30, 1950, over TV station KSTP.

Bell Labs’ 1947 invention of the transistor significantly improved the efficiency and reliability of computers and modern electronics over vacuum tubes and mechanical relays.

Also, in 1947, the first concept paper of a wireless cellular telephone network began at Bell Labs; however, the technology needed to build it did not yet exist.

This proposal envisioned a geographical cellular network “following” telephone users as they moved throughout a network topology, handing off voice calls from one radio cell site to another without interruption. Its design looked like interconnected honeycombs.

AT&T activated the first working US commercial cellular telephone system in Chicago, IL, in 1983.

The first long-distance transatlantic coaxial copper-core telephone cable system called TAT-1 (Transatlantic No. 1) from Newfoundland and Labrador, Canada to Oban, Scotland was completed Sept. 25, 1956.

TAT-1 was a joint venture of the General Post Office of the UK, Canadian Overseas Telecommunications Corporation, and AT&T.

In 1949, Bell Labs first developed the telephone line modem (modulator/demodulator) to change digital data signals into modulated analog signals suitable for broadcast over analog telephone circuits, giving birth to the modern telephone-line modem.

Bell Lab’s prior work with the telephotography machine aided the modem’s development.

In 1958, the North American Air Defense (NORAD) first used modems to transmit digital computer data over dedicated analog signaling telephone wires.

AT&T manufactured a 300 bps (bits per second) Bell 103 modem, which became available for the public and private businesses to use over the conventional telephone network in 1962.

A 1960 Bell System technical journal described its dual-tone multi-frequency (DTMF) keypad for pushbutton “touch-tone” telephone dialing, saying it would eventually replace the rotary dial used in a standard telephone.

AT&T first demonstrated touch-tone dialing to the public at the 1962 Seattle World’s Fair.

Nov. 18, 1963, the first touch-tone keypad dialers installed in telephones for public use were in the Greensburg and Carnegie, PA telephone exchanges.

The first public touch-tone telephone was the Western Electric model 1500, which had a keypad layout of 10 buttons, with the numeral one at the top left and zero in the bottom row.

Older telephone folks seem to think the number sign aka hashtag/pound (#) and star (*) key buttons, added in 1968, were used to access computers through telephone lines.

And yes, I have a vintage 10-button Western Electric model 1500 telephone.

In 1979, my hometown of Winsted’s first touch-tone dialing service was at St. Mary’s Hospital and Home, with the installation of the digital computerized telephone system, the GTD-120 PABX (Private Automatic Branch Exchange) manufactured by GTE Automatic Electric in Northlake, IL. It was one of Minnesota’s first digital business telephone systems and was installed and maintained by highly-skilled and dedicated technicians from the Winsted Telephone Company.

A year later, Winsted Telephone Company made significant modifications to its central dial office system by installing dual-tone multi-frequency receiver equipment, allowing all of their local subscribers the option of using touch-tone telephones.

In 1996, Lucent Technologies (started by AT&T) had taken over AT&T’s Bell Labs development and research.

April 2, 2006, the French company, Alcatel, acquired Lucent Technologies and Bell Labs.

Nov. 3, 2016, the Finnish communications and technology company, NOKIA, purchased Alcatel-Lucent (and Bell Labs) for $16.6 billion.

Today, Bell Labs is headquartered in Murray Hill, NJ, and employs more than 340 people.

Visit Bell Labs at https://www.bell-labs.com.

Below are photos of my Western Electric model 1500 telephone: