Modern push-button telephone
The push-button telephone is a telephone that uses push-buttons or keys for dialing a telephone number to place a call to another telephone subscriber. Western Electric experimented as early as 1941 with methods of using mechanically activated reeds to produce two tones for each of the ten digits,[1] but it wasn't until 18 November 1963 when the Bell System in the United States officially introduced dual-tone multi-frequency (DTMF) technology under its registered Touch-Tone® mark. Over the next few decades Touch-Tone service replaced traditional pulse dialing technology as used in rotary dial telephones since 1891.[2] Touch-Tone technology eventually became a world-wide standard for telecommunication signaling.
History
The concept of the use of a push-button in telephony originated around 1887 with a device called the micro-telephone push-button, but it was not a automatic dialing system as known today.
In the 1950s AT&T conducted extensive studies and concluded that push-button dialing was much faster than rotary dialing.[3] On November 18, 1963, the first electronic push-button system with Touch-Tone dialing was offered by Bell Telephone to AT&T customers in Carnegie and Greensburg, Pennsylvania.[3][4]
Typical push-button phone in the 1970s and early 80s, with 12 keys
This phone, the Western Electric 1500, had only ten buttons. In 1968 it was replaced by the twelve-button model 2500, adding the asterisk or star (*) and pound or hash (#) keys. South African-born Bell Labs psychologist John Elias Karlin (1918–2013) led the team that designed the telephone, which introduced all-number dialing, with the "1-2-3" on the top row for accuracy.[5]
Although push-button touch-tone phones made their debut to the general public in 1963, the older rotary dial telephone still was common for many years. In the 1970s the majority of phone users still had rotary phones. Adoption of the push-button phone was steady, but it took a long time for them to appear in some areas.[6] At first it was primarily businesses that adopted push-button phones.[7] By 1979, the touch-tone phone was gaining popularity,[7] but it wasn't until the 1980s that the majority of customers owned push-button telephones in their homes; by the 1990s, it was the overwhelming majority.
Some exchanges no longer support pulse-dialing,[6] and rotary telephones are generally considered obsolete.[8][9] Rotary telephones are now largely considered a novelty,[10] and are not compatible with some modern telephone features, though enthusiasts may adapt pulse-dialing telephones using a pulse-to-tone converter.[11]
Touch-tone
The international standard for push-button telephones utilizes dual-tone multi-frequency (DTMF) signaling, more commonly known as Touch-Tone dialing. It replaced the older and slower pulse dial system.[12][13] The push-button touch-tone format is also used for all cell phones.[7]
The telephone buttons are typically arranged in a 3-by-4 grid, including the digits zero through nine and two additional keys labeled with an asterisk (*) and the pound or hash sign (#) to represent the 11th and 12th DTMF signals. These signals accommodate various additional services and customer-controlled calling features.[14][3] The DTMF system assigns specific frequencies to each column and row of push-buttons in the telephone keypad; the columns in the push-button pad have higher-frequency tones, and rows have lower-frequency tones in the audible range. When a buttons is pressed the dial generates a combination signal of the two frequencies for the selected row and column, a dual-tone signal, which is transmitted over the phone line to the telephone exchange.[3]
Features
Push-button telephones have allowed for advancement in telecommunications.[1][4] Telephones and telecommunications networks have benefited from continued advancements in digital electronics.[12][15] Electronics within the push-button telephone provides for last number re-dial and storage of commonly called numbers. 'Caller line identification' or "Caller-ID", allows the number of the caller to be displayed on the telephone handset. Some models support additional features, such as retrieval of information and data or code and PIN entry.[16] Push-button telephones also allow for Internet-based telecommunications such as VoIP.[11]
See also
References
- ^ a b Push. Click. Touch. - History of the Button - 1963: Pushbutton Telephone - December 11, 2006
- ^ The New York Times - "When Dials Were Round and Clicks Were Plentiful"- by Catherine Greenman, October, 1999
- ^ a b c d Britannica. - Call number dialing
- ^ a b Engineering Pathway - Bell Telephone introduces push button telephone - by Alice Agogino - November 18, 2009
- ^ [1]
- ^ a b I Remember JFK - Push-Button Telephones
- ^ a b c Wise Geek - What is a Touch Tone Telephone?
- ^ TimesDaily.com - Advances make many items close to obsolete - by Tom Smith & Bernie Delinski - October 14, 2009 - Retrieved February 10, 2010
- ^ The Free Lance-Star - Aug 12, 1994, by Michael Zitz, page 1 - Rotary phone users in info highway's slow lane
- ^ Sacramento Business Journal - Rotary phones ring true for few - all but gone from workplace - March 9, 2001
- ^ a b oldphoneworks
- ^ a b University of Salford - Computer Networking and Telecommunications Research - General Telephones
- ^ Wise Geek - What is a Rotary Phone?
- ^ Great Achievements-Telephone Timeline
- ^ An (Incomplete) History of Digital Technology - 2010 - East Hartford Public Schools
- ^ Mobile Phone As Home Computer - Philip Greenspun
