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Operator Toll Dialing
Operator Toll Dialing was a telephone call routing and toll-switching system for the Bell System and the independent telephone companies in the United States and Canada that was developed in the 1940s. It automated the switching and billing of long-distance calls. The concept and technology evolved from the General Toll Switching Plan of 1929, and gained technical merits by the cutover of a new type of crossbar switching system (No. 4XB) in Philadelphia to commercial service in August 1943. This was the first system of its kind for automated forwarding of calls between toll switching centers, but it served customers only for regional toll traffic. It established initial experience with automatic toll switching for the design of a nationwide effort that was sometimes referred to as Nationwide Operator Toll Dialing. By the time of first public promotions of Nationwide Operator Toll Dialing to the general telecommunication industry in 1945, c. 5% of the 2.7 million toll board calls ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user. The term is derived from el, τῆλε (''tēle'', ''far'') and φωνή (''phōnē'', ''voice''), together meaning ''distant voice''. A common short form of the term is ''phone'', which came into use early in the telephone's history. In 1876, Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice at a second device. This instrument was further developed by many others, and became rapidly indispensable in business, government, and in households. The essential elements of a telephone are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell System
The Bell System was a system of telecommunication companies, led by the Bell Telephone Company and later by the American Telephone and Telegraph Company (AT&T), that dominated the telephone services industry in North America for over one hundred years from its creation in 1877 until its antitrust breakup in 1983. The system of companies was often colloquially called Ma Bell (as in "Mother Bell"), as it held a vertical monopoly over telecommunication products and services in most areas of the United States and Canada. At the time of the breakup of the Bell System in the early 1980s, it had assets of $150 billion (equivalent to $ billion in ) and employed over one million people. Ever since the 1910s, American antitrust regulators had been observing and accusing the Bell System of abusing its monopoly power, and had brought legal action multiple times over the decades, until in 1974 the Antitrust Division of the U.S. Department of Justice brought a lawsuit against Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long-distance Calling
In telecommunications, a long-distance call (U.S.) or trunk call (also known as a toll call in the U.K. ) is a telephone call made to a location outside a defined local calling area. Long-distance calls are typically charged a higher billing rate than local calls. The term is not necessarily synonymous with placing calls to another telephone area code. Long-distance calls are classified into two categories: national or domestic calls which connect two points within the same country, and international calls which connect two points in different countries. Within the United States there is a further division into long-distance calls within a single state (intrastate) and interstate calls, which are subject to different regulations (counter-intuitively, calls within states are usually more expensive than interstate calls). Not all interstate calls are long-distance calls. Since 1984 there has also been a distinction between intra-local access and transport area (LATA) calls and those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Toll Switching Plan
The General Toll Switching Plan was a systematic nationwide effort by the American Telephone and Telegraph Company (AT&T) of organizing the telephone toll circuits and cable routes of the nation, and of streamlining the operating principles and technical infrastructure for connecting long-distance telephone calls in North America. This involved the design of a hierarchical system of toll-switching centers, a process that had found substantial maturity by 1929. The switching plan was principally operated by the ''Long Lines'' division of the Bell System in cooperation with independent telephone companies under the decree of the Kingsbury Commitment, reached with the United States government in 1913. The General Toll Switching Plan was a system manually operated by long-distance telephone operators. It was the forerunner of an automated system called Nationwide Operator Toll Dialing that was begun in 1943, which eventually led to Direct Distance Dialing (DDD) within the framework of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Numbering Plan
A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone number A telephone number is a sequence of digits assigned to a landline telephone subscriber station connected to a telephone line or to a wireless electronic telephony device, such as a radio telephone or a mobile telephone, or to other devices f ...s 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 in each of the administrative regions of the public switched telephone network (PSTN) and in private telephone networks. For 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Original North American Area Codes
The original North American area codes were established by the American Telephone & Telegraph Company (AT&T) in 1947, following the demonstration of regional Operator Toll Dialing during the World War II period. The program had the goal of speeding the connecting times for long-distance calling by eliminating intermediary telephone operators. Expanding this technology for national use required a comprehensive and universal, continent-wide telephone numbering plan. The new numbering plan established a uniform destination addressing and call routing system for all telephone networks in North America which had become an essential public service. It had the eventual benefit of direct distance dialing (DDD) by telephone subscribers. The initial ''Nationwide Numbering Plan'' of 1947 established eighty-six numbering plan areas (NPAs) that principally followed existing U.S. state and Canadian provincial boundaries, but fifteen states and provinces were subdivided further. Forty NPAs wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Laboratories Record
''Bell Laboratories Record'' (BLR) was a publication of the ''Bureau of Publication'' of the American Telephone and Telegraph Company (AT&T) and Bell Laboratories. It commenced distribution as a house organ for the employees and associates of the laboratories and the Bell System in September 1925, shortly after the founding of Bell Labs as a separate corporate entity. The first ''Director of Publication'' was John Mills, leading three managing and assisting editors, and an eleven-member editorial advisory board. The magazine reported personal, scientific, and organizational information, scholarly articles, and news of interest within the laboratories, Western Electric, and AT&T. It included descriptions of technologies created at many Bell System locations for basic research, devices, technologies, systems, and operations research relevant to telephone company, manufacturing, and government applications. It was slimmer and less scholarly than the ''Bell Labs Technical Journal''. ... [...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 the in-ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Distance Dialing
Direct distance dialing (DDD) is a telecommunication service feature in North America by which a caller may, without operator assistance, call any other user outside the local calling area. Direct dialing by subscribers typically requires extra digits 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-digit directory number. Local telephone numbers still consisted of the first two letters of the central office name and five digits. On ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notes On The Network
''Notes on the Network'' is a publication of the American Telephone & Telegraph Company (AT&T) that outlines the state, technology, and operating principles of the public switched telephone network in the United States and Canada, and the other member regions of the North American Numbering Plan. The origins of publication date back to the 1945 communications about ''Nationwide Operator Toll Dialing'' disseminated by AT&T to the Bell System companies and to the independent telephone operators via the ''Dial interexchange Committee'' of the ''United States Independent Telephone Association'' (USITA). In 1955, AT&T published the first extensive edition under the title ''Notes on Nationwide Dialing'', which was updated the following year (1956) under the title ''Notes on Distance Dialing''. Additional editions were issued in 1961, 1968, and 1975. The first use of the title ''Notes on the Network'' was for the 1980 edition. After the breakup of AT&T and the Bell System, the documen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trunk Prefix
A trunk prefix is a digit sequence to be dialed before a telephone number to initiate a telephone call for the purpose of selecting an appropriate telecommunications circuit by which the call is to be routed. Making a domestic (national) telephone call usually requires the dialing of a single or two-digit national trunk prefix preceding any area codes and the destination subscriber number. In most countries, such as Australia, China, India, France, Germany, Indonesia, Japan, the Netherlands, Sweden, and the United Kingdom, the trunk prefix is 0. For international telephone calls, the national trunk prefix is not dialed; instead, an international trunk prefix (or "+") is typically required, followed by the destination's country code. Example Assume that a call is to be made to a customer in the Australian Area/State of Queensland with the local number of 3333 3333 and the area code 7. A caller from outside Australia must dial the international call prefix of the originating coun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subscriber Trunk Dialling
Subscriber trunk dialling (STD), also known as subscriber toll dialing, is a telephone numbering plan feature and telecommunications technology for the dialling of trunk calls by telephone subscribers without the assistance from switchboard operators. Switching systems to enable automatic dialling of long distance calls by subscribers were introduced in the United Kingdom on 5 December 1958. The system used area codes that were based on the letters in a town's name. A ceremonial first call was made by Queen Elizabeth II from Bristol to Edinburgh. A similar service, built on crossbar equipment, using regionally structured numbering, rather than alphanumeric codes, was experimentally introduced by P&T in Ireland in 1957, with the first services being in Athlone. A full service was rolled out in 1958, initially to exchanges in Cork and then Dublin and its hinterland, and gradually to all areas with automatic exchanges. The term 'STD call' was once commonly used in the UK, Irela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
