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Push-button Telephone
A push-button telephone is a telephone that has buttons or keys for dialing a telephone number, in contrast to a rotary dial used in earlier telephones. Western Electric experimented as early as 1941 with methods of using mechanically activated reeds to produce two tones for each of the ten digits and by the late 1940s such technology was field-tested in a Number Five Crossbar Switching System, No. 5 Crossbar switching system in Pennsylvania.Push. Click. Touch. – History of the Button – 1963: Pushbutton Telephone – December 11, 2006 The technology at that time proved unreliable and it was not until after the invention of the transistor that push-button technology became practical. The Bell System selected Findlay, Ohio as the first city in the U.S. for marketing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Model 500 Telephone
The Western Electric model 500 telephone series was the standard domestic desk telephone set issued by the Bell System in North America from 1950 through the 1984 Bell System divestiture. The successor to the model 302 telephone, the model 500's modular construction compared to previous types simplified manufacture and repair and facilitated a large number of variants with added features. Dual-tone multi-frequency signaling, Touch-tone service was introduced to residential customers in 1963 with the #Model 1500, model 1500 telephone, which had a push-button pad for the ten digits. The #Model 2500, model 2500 telephone, introduced in 1968, added the Asterisk#Telephony, * (star) and Number sign#Computing, # (square, pound) keys. The model 500 telephone series and its derivatives were very popular and common among North American businesses and households throughout the latter half of the 20th century. The development of new simpler telephone set designs, the advent of mobile phones, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulse Dial
Pulse dialing is a signaling technology in telecommunications in which a direct current local loop circuit is interrupted according to a defined coding system for each signal transmitted, usually a digit. This lends the method the often used name loop disconnect dialing. In the most common variant of pulse dialing, decadic dialing, each of the ten Arabic numerals are encoded in a sequence of up to ten pulses. The most common version decodes the digits 1 through 9, as one to nine pulses, respectively, and the digit 0 as ten pulses. Historically, the most common device to produce such pulse trains is the rotary dial of the telephone, lending the technology another name, rotary dialing. The pulse repetition rate was historically determined based on the response time needed for electromechanical switching systems to operate reliably. Most telephone systems used the nominal rate of ten pulses per second, but operator dialing within and between central offices often used pulse r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Telephone & Telegraph
AT&T Corporation, an abbreviation for its former name, the American Telephone and Telegraph Company, was an American telecommunications company that provided voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agencies. During the Bell System's long history, AT&T was at times the world's largest telecommunications company, the world's largest cable television operator, and a regulated monopoly. At its peak in the 1950s and 1960s, it employed one million people and its revenue ranged between US$3 billion in 1950 ($ in present-day terms) and $12 billion in 1966 ($ in present-day terms). In 2005, AT&T was acquired by "Regional Bell Operating Company, Baby Bell" and former subsidiary SBC Communications for more than $16 billion ($ in present-day terms). SBC then changed its name to AT&T, AT&T Inc., with AT&T Corporation continuing to exist as a long-distance calling subsidiary until its dissolution o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code
A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, reachable by a system of destination code routing. Telephone numbering plans are defined world-wide, as well as within each of the administrative regions of the public switched telephone network (PSTN), and in private telephone networks. In public numbering systems, geographic location typically plays a role in the sequence of numbers assigned to each telephone subscriber. Many numbering plan administrators subdivide their territory of service into geographic regions designated by a prefix, often called an area code or city code, which is a set of digits forming the most-significant part of the dialing sequence to reach a telephone subscriber. Within such regions designated by area codes, locally unique telephone number are assigned based on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exchange Names
A telephone exchange name or central office name was a distinguishing and memorable name assigned to a central office. It identified the switching system to which a telephone was connected, and facilitated the connection of telephone calls between switching systems in different localities. While small towns and rural areas might each be served by a single exchange, large cities were served by multiple switching systems, either distributed in the community constituting multiple exchange areas, or sometimes hosted in the same building to serve a densely populated area. Central offices were usually identified by names that were locally significant. The leading letters of a central office name were used as the leading components of the telephone number representation, so that each telephone number in the area was unique. These letters were mapped to the digits of the dial, which was indicated visibly on the dial's numbering plate. Several systematic telephone numbering plans existed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-frequency Signaling
In telephony, multi-frequency signaling (MF) is a type of signaling that was introduced by the Bell System after World War II. It uses a combination of audible tones for address (telephone number) transport and supervision signaling on trunk lines between central offices. The signaling is sent '' in-band'' over the same channel as the bearer channel used for voice traffic. Multi-frequency signaling defines electronic signals that consist of a combination of two audible frequencies, usually selected from a set of six frequencies. Over several decades, various types of MF signaling were developed, including national and international varieties. The CCITT standardization process specified the American Bell System version as ''Regional Standard No. 1'', or Signalling System R1, and a corresponding European standard as Signalling System R2. Both were largely replaced by digital systems, such as Signalling System 7, which operate out-of-band on a separate data network. Because of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In-band Signaling
In telecommunications, in-band signaling is the sending of control information within the same band or channel used for data such as voice or video. This is in contrast to out-of-band signaling which is sent over a different channel, or even over a separate network. In-band signals may often be heard by telephony participants, while out-of-band signals are inaccessible to the user. The term is also used more generally, for example of computer data files that include both literal data, and metadata and/or instructions for how to process the literal data. Telephony When dialing from a land-line telephone, the telephone number is encoded and transmitted across the telephone line in form of dual-tone multi-frequency signaling (DTMF). The tones control the telephone system by instructing the telephone switch where to route the call. These control tones are sent over the same channel, the copper wire, and in the frequency range (300 Hz to 3.4 kHz) as the audio of the tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Distance Dialing
Direct distance dialing (DDD) is a telecommunications service in North America by which a caller may call any other subscriber outside the local calling area without operator assistance, DDD was introduced in the United States in 1951, on a trial basis, with service from Englewood, New Jersey. Direct long-distance dialing by subscribers requires extra digits, called an area code, to be dialed as prefixes to the directory telephone number of the destination. International Direct Distance Dialing (IDDD) extends the system beyond the geographic boundaries of the North American Numbering Plan (NANP). History The first direct-dialed long-distance telephone calls were possible in the New Jersey communities of Englewood and Teaneck. Customers of the ENglewood 3, ENglewood 4 and TEaneck 7 exchanges, who could already dial telephone numbers in the New York City area, could place calls to eleven major cities across the United States by dialing the three-digit area code and the seven-di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Almon Brown Strowger
Almon Brown Strowger (; February 11, 1839 – May 26, 1902) was an American inventor for whom the Strowger switch, an electromechanical telephone exchange technology, is named. Early years Strowger was born in Penfield, New York, near Rochester, the grandson of the second settler and first miller in Penfield. Little is known about his early life. It is said that if his mother gave her children a task, Strowger and his brothers would often try to devise a machine to do the task for them. He taught school in Penfield for a time. In October 1861, he enlisted as a Musician in Company A, 8th New York Cavalry Regiment, to fight in the American Civil War. He was promoted to Sergeant and Chief Trumpeter of the regiment in February 1864, and ended the war as a Second Lieutenant. He was wounded in action at the Third Battle of Winchester in 1864, and discharged later that year. After the Civil War, it appears he first became a country school teacher before he became an underta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed Dialing
Speed dial was a function available on many telephone systems allowing the user to place a call by pressing a reduced number of keys. This function was particularly useful for phone users who dial certain numbers on a regular basis. In most cases, the user stores these numbers in the phone's memory for future use. The speed dial numbers were usually accessed by pressing a predetermined key or keys on the phone, followed by a one or two-digit code which the user assigned to each number; however, for ease of use, on many systems a call may be placed by pressing and holding one key on the numeric keypad. Speed dialing was also available via Custom Calling features from the Telephone Company's Central Office. The numbers were programmed by the subscriber through the standard telephone dial, and speed dial calls were placed by dialing simply the digit and waiting a few seconds on a standard rotary dial phone and an older 10 key Touch Tone phone, or by dialing the number and the # key ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOS Memory
Semiconductor memory is a digital electronic semiconductor device used for digital data storage, such as computer memory. It typically refers to devices in which data is stored within metal–oxide–semiconductor (MOS) memory cells on a silicon integrated circuit memory chip. There are numerous different types using different semiconductor technologies. The two main types of random-access memory (RAM) are static RAM (SRAM), which uses several transistors per memory cell, and dynamic RAM (DRAM), which uses a transistor and a MOS capacitor per cell. Non-volatile memory (such as EPROM, EEPROM and flash memory) uses floating-gate memory cells, which consist of a single floating-gate transistor per cell. Most types of semiconductor memory have the property of random access, which means that it takes the same amount of time to access any memory location, so data can be efficiently accessed in any random order. This contrasts with data storage media such as CDs which read an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Directory
A telephone directory, commonly called a telephone book, telephone address book, phonebook, or the white and yellow pages, is a listing of telephone subscribers in a geographical area or subscribers to services provided by the organization that publishes the directory. Its purpose is to allow the telephone number of a subscriber identified by name and address to be found. The advent of the Internet, search engines, and smartphones in the 21st century greatly reduced the need for a paper phone book. Some communities, such as Seattle and San Francisco, sought to ban their unsolicited distribution as wasteful, unwanted and harmful to the environment.Yellow Pages ruling endangers SF ban Heather Knight, '' |
