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Vanguard Cellular
Vanguard Cellular Systems, Inc. was a mobile phone carrier with headquarters in Greensboro, North Carolina. It was the largest independent non-wireline cellular carrier in the 1990s. It was acquired by AT&T in 1999. History In September 1982, the company Collins, Hagel, and Clarke was formed by Bill Collins, Don Clarke, Dave Smith, and Chuck Hagel. In late 1984, "Collins, Hagel and Clarke and a group of North Carolina investors rolled all their cellular operations into a new company they called vanguard, dedicated to the telecommunications business. While the three original partners all initially served on the Vanguard board, Hagel was the only one of the three who became a Vanguard employee. He was an executive vice president until 1987." In 1999, Vanguard was acquired by AT&T. Operations Vanguard Cellular Systems operated cellular systems in Maine, New York, Pennsylvania, West Virginia, South Carolina, and Florida and owned interests in other systems throughout the United States ...
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Mobile Phone
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular network architecture and, therefore, mobile telephones are called ''cellular telephones'' or ''cell phones'' in North America. In addition to telephony, digital mobile phones ( 2G) support a variety of other services, such as text messaging, multimedia messagIng, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, video games and digital photography. Mobile phones offering only those capabilities are known as fea ...
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Greensboro, North Carolina
Greensboro (; formerly Greensborough) is a city in and the county seat of Guilford County, North Carolina, United States. It is the third-most populous city in North Carolina after Charlotte and Raleigh, the 69th-most populous city in the United States, and the largest city in the Piedmont Triad metropolitan region. At the 2020 census, its population was 299,035. Three major interstate highways (Interstate 40, Interstate 85, and Interstate 73) in the Piedmont region of central North Carolina were built to intersect at this city. In 1808, Greensborough (the spelling before 1895) was planned around a central courthouse square to succeed Guilford Court House as the county seat. The county courts were thus placed closer to the county's geographical center, a location more easily reached at the time by the majority of the county's citizens, who traveled by horse or on foot. In 2003, the previous Greensboro–Winston-Salem– High Point metropolitan statistical area was redefin ...
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AT&T
AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile telephone services in the U.S. , AT&T was ranked 13th on the ''Fortune'' 500 rankings of the largest United States corporations, with revenues of $168.8 billion. During most of the 20th century, AT&T had a monopoly on phone service in the United States. The company began its history as the American District Telegraph Company, formed in St. Louis in 1878. After expanding services to Arkansas, Kansas, Oklahoma and Texas, through a series of mergers, it became Southwestern Bell Telephone Company in 1920, which was then a subsidiary of American Telephone and Telegraph Company. The latter was a successor of the original Bell Telephone Company founded by Alexander Graham Bell in 1877. The American Bell Telephone Company formed the American Teleph ...
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Wall Street Journal
''The Wall Street Journal'' is an American business-focused, international daily newspaper based in New York City, with international editions also available in Chinese and Japanese. The ''Journal'', along with its Asian editions, is published six days a week by Dow Jones & Company, a division of News Corp. The newspaper is published in the broadsheet format and online. The ''Journal'' has been printed continuously since its inception on July 8, 1889, by Charles Dow, Edward Jones, and Charles Bergstresser. The ''Journal'' is regarded as a newspaper of record, particularly in terms of business and financial news. The newspaper has won 38 Pulitzer Prizes, the most recent in 2019. ''The Wall Street Journal'' is one of the largest newspapers in the United States by circulation, with a circulation of about 2.834million copies (including nearly 1,829,000 digital sales) compared with ''USA Today''s 1.7million. The ''Journal'' publishes the luxury news and lifestyle magazine ' ...
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Nortel
Nortel Networks Corporation (Nortel), formerly Northern Telecom Limited, was a Canadian multinational telecommunications and data networking equipment manufacturer headquartered in Ottawa, Ontario, Canada. It was founded in Montreal, Quebec, in 1895 as the Northern Electric and Manufacturing Company. Until an antitrust settlement in 1949, Northern Electric was owned principally by Bell Canada and the Western Electric Company of the Bell System, producing large volumes of telecommunication equipment based on licensed Western Electric designs. At its height, Nortel accounted for more than a third of the total valuation of all companies listed on the Toronto Stock Exchange (TSX), employing 94,500 people worldwide. In 2009, Nortel filed for bankruptcy protection in Canada and the United States, triggering a 79% decline of its corporate stock price. The bankruptcy case was the largest in Canadian history and left pensioners, shareholders and former employees with enormous losses. ...
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Advanced Mobile Phone System
Advanced Mobile Phone System (AMPS) was an analog mobile phone system standard originally developed by Bell Labs and later modified in a cooperative effort between Bell Labs and Motorola. It was officially introduced in the Americas on October 13, 1983,Private Line

and was deployed in many other countries too, including Israel in 1986, Australia in 1987, Singapore in 1988, and Pakistan in 1990. It was the primary analog mobile phone system in North America (and other locales) through the 1980s and into the 2000s. As of February 18, 2008, carriers in the United States were no longer required to support AMPS and companies ...
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Time Division Multiple Access
Time-division multiple access (TDMA) is a channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This allows multiple stations to share the same transmission medium (e.g. radio frequency channel) while using only a part of its channel capacity. Dynamic TDMA is a TDMA variant that dynamically reserves a variable number of time slots in each frame to variable bit-rate data streams, based on the traffic demand of each data stream. TDMA is used in the digital 2G cellular systems such as Global System for Mobile Communications (GSM), IS-136, Personal Digital Cellular (PDC) and iDEN, and in the Digital Enhanced Cordless Telecommunications (DECT) standard for portable phones. TDMA was first used in satellite communication systems by Western Union in its Westar 3 communications satellite ...
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Digital AMPS
IS-54 and IS-136 are second-generation ( 2G) mobile phone systems, known as Digital AMPS (D-AMPS), and a further development of the North American 1G mobile system Advanced Mobile Phone System (AMPS). It was once prevalent throughout the Americas, particularly in the United States and Canada since the first commercial network was deployed in 1993. D-AMPS is considered end-of-life, and existing networks have mostly been replaced by GSM/GPRS or CDMA2000 technologies. This system is most often referred to as TDMA. That name is based on the abbreviation for time-division multiple access, a common multiple access technique which is used in most 2G standards, including GSM, as well as in IS-54 and IS-136. D-AMPS competed against GSM and systems based on code-division multiple access (CDMA). D-AMPS uses existing AMPS channels and allows for smooth transition between digital and analog systems in the same area. Capacity was increased over the preceding analog design by dividing each ...
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Defunct Mobile Phone Companies Of The United States
Defunct (no longer in use or active) may refer to: * ''Defunct'' (video game), 2014 * Zombie process or defunct process, in Unix-like operating systems See also * * :Former entities * End-of-life product * Obsolescence Obsolescence is the state of being which occurs when an object, service, or practice is no longer maintained or required even though it may still be in good working order. It usually happens when something that is more efficient or less risky r ...
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Defunct Companies Based In North Carolina
Defunct (no longer in use or active) may refer to: * ''Defunct'' (video game), 2014 * Zombie process or defunct process, in Unix-like operating systems See also * * :Former entities * End-of-life product * Obsolescence Obsolescence is the state of being which occurs when an object, service, or practice is no longer maintained or required even though it may still be in good working order. It usually happens when something that is more efficient or less risky r ...
{{Disambiguation ...
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Companies Based In Greensboro, North Carolina
A company, abbreviated as co., is a legal entity representing an association of people, whether natural, legal or a mixture of both, with a specific objective. Company members share a common purpose and unite to achieve specific, declared goals. Companies take various forms, such as: * voluntary associations, which may include nonprofit organizations * business entities, whose aim is generating profit * financial entities and banks * programs or educational institutions A company can be created as a legal person so that the company itself has limited liability as members perform or fail to discharge their duty according to the publicly declared incorporation, or published policy. When a company closes, it may need to be liquidated to avoid further legal obligations. Companies may associate and collectively register themselves as new companies; the resulting entities are often known as corporate groups. Meanings and definitions A company can be defined as an "artificial per ...
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