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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] |
Telecommunications
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent Session (computer science), communication sessions. Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the electrical telegraph, telegraph, telephone, television, and radio. Early telecommunication networks used metal wires as the medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In the first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi, who won the 1909 Nobel Prize in Physics. Othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 312
Area code 312 is a telephone area code in the North American Numbering Plan for the city of Chicago, including downtown, the Chicago Loop, and its immediate environs. The numbering plan area is completely surrounded by area code 773, which serves the rest of Chicago. Both area codes form an overlay complex with area code 872. 312 is an enclave area code, and is roughly bounded by Illinois Route 64, North Avenue on the north, Western Avenue on the west, and 35th Street on the south, with Lake Michigan to the east. In terms of geographic area covered, 312 is one of the smallest area codes in the nation, encompassing only a few square miles. History Area code 312 was assigned to one of the original 86 numbering plan areas (NPAs) created in 1947 for the North American Numbering Plan. As a result of Illinois' dense population, particularly in the north, the state was split between four NPAs, given that each NPA could only accommodate approximately 500 central offices. Area code 312 o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pittsburgh
Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. It is the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania (after Philadelphia) and the List of United States cities by population, 67th-most populous city in the U.S., with a population of 302,971 as of the 2020 United States census, 2020 census. The city is located in Western Pennsylvania, southwestern Pennsylvania at the confluence of the Allegheny River and Monongahela River, which combine to form the Ohio River. It anchors the Greater Pittsburgh, Pittsburgh metropolitan area, which had a population of 2.457 million residents and is the largest metro area in both the Ohio Valley and Appalachia, the Pennsylvania metropolitan areas, second-largest in Pennsylvania, and the List of metropolitan statistical areas, 26th-largest in the U.S. Pittsburgh is the principal city of the greater Pittsburgh–New Castle–Weirton combined statistic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 412
Area code 412 is a telephone area code in the North American Numbering Plan (NANP) for the Commonwealth of Pennsylvania. The numbering plan area (NPA) comprises the city of Pittsburgh, most of surrounding Allegheny County, and small portions of Washington and Westmoreland counties. The area code was one of the original North American area codes created in 1947, when it was assigned to the entire southwestern corner of the state. On August 17, 2001, the numbering plan area was converted to an overlay complex with area code 878, which also forms an overlay with area code 724, in the surroundings of the 412 service area. History When the American Telephone and Telegraph Company (AT&T) created the first nationwide telephone numbering plan for the continental United States and Canada in 1947, Pennsylvania was divided into four numbering plan areas. Area code 412 was assigned to the southwestern part of the state, from Butler County to the West Virginia border. On February 1, 1998, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philadelphia
Philadelphia ( ), colloquially referred to as Philly, is the List of municipalities in Pennsylvania, most populous city in the U.S. state of Pennsylvania and the List of United States cities by population, sixth-most populous city in the United States, with a population of 1,603,797 in the 2020 United States census, 2020 census. The city is the urban core of the Philadelphia metropolitan area (sometimes called the Delaware Valley), the nation's Metropolitan statistical area, seventh-largest metropolitan area and ninth-largest combined statistical area with 6.245 million residents and 7.379 million residents, respectively. Philadelphia was founded in 1682 by William Penn, an English Americans, English Quakers, Quaker and advocate of Freedom of religion, religious freedom, and served as the capital of the Colonial history of the United States, colonial era Province of Pennsylvania. It then played a historic and vital role during the American Revolution and American Revolutionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 215
Year 215 ( CCXV) was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Laetus and Sulla (or, less frequently, year 968 ''Ab urbe condita''). The denomination 215 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Caracalla's troops massacre the population of Alexandria, Egypt, beginning with the leading citizens. The emperor was angry about a satire, produced in Alexandria, mocking his claim that he killed Geta in self-defense. * A coin, the Antoninianus, is introduced. The weight of this coin is a mere 1/50 of a pound. Copper disappears gradually, and by the middle of the third century, with Rome's economy in crisis, the Antonianus will be the only official currency. China * Zhang Liao holds off Sun Quan's invasion force at the Battle of Xiaoyao Ford in Hefei, China. Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oakland, California
Oakland is a city in the East Bay region of the San Francisco Bay Area in the U.S. state of California. It is the county seat and most populous city in Alameda County, California, Alameda County, with a population of 440,646 in 2020. A major West Coast of the United States, West Coast port, Oakland is the most populous city in the East Bay, the third most populous city in the Bay Area, and the eighth most populous city in California. It serves as the Bay Area's trade center: the Port of Oakland is the busiest port in Northern California, and the fifth- or sixth-busiest in the United States. A charter city, Oakland was municipal corporation, incorporated on May 4, 1852, in the wake of the state's increasing population due to the California gold rush. Oakland's territory covers what was once a mosaic of California coastal prairie, California coastal terrace prairie, oak woodland, and north coastal scrub. In the late 18th century, it became part of a large ''rancho'' grant in the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 415
Area codes 415 and 628 are telephone area codes in the North American Numbering Plan (NANP) for the city of San Francisco and its northern suburbs in Marin County (across the Golden Gate), and the northeast corner of San Mateo County in the U.S. state of California. Area code 415 was one of the eighty-six original North American area codes established in 1947, but modified in geographic configuration later. Area code 628 was assigned in 2015 to form an overlay in that numbering plan area in mitigation of central office prefix exhaustion. History When the American Telephone and Telegraph Company (AT&T) introduced the first nationwide telephone numbering plan for Operator Toll Dialing in 1947, the state of California was divided into three numbering plan areas (NPAs) arranged as geographical zones in the southern part, the central part, and the northern part of the state. Area code 415 was assigned to central California, south of area code 916, and north of area code 213. It stretch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milwaukee
Milwaukee is the List of cities in Wisconsin, most populous city in the U.S. state of Wisconsin. Located on the western shore of Lake Michigan, it is the List of United States cities by population, 31st-most populous city in the United States and the fifth-most populous city in the Midwest with a population of 577,222 at the 2020 United States census, 2020 census. It is the county seat of Milwaukee County, Wisconsin, Milwaukee County. The Milwaukee metropolitan area is the Metropolitan statistical area, 40th-most populous metropolitan area in the U.S. with 1.57 million residents. Founded in the early 19th century and incorporated in 1846, Milwaukee grew rapidly due to its location as a port city. History of Milwaukee, Its history was heavily influenced by German immigrants and it continues to be a Germans in Milwaukee, center for German-American culture, specifically known for Beer in Milwaukee, its brewing industry. The city developed as an industrial powerhouse during the 19t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 414
Area code 414 is a telephone area code of the North American Numbering Plan for the area around and including the city of Milwaukee in the state of Wisconsin. History The area code was created in October 1947, along with area code 715, as one of the two original area codes assigned to Wisconsin. The numbering plan area (NPA) originally included most of the southern and northeastern parts of Wisconsin, stretching from Lake Michigan to the Minnesota and Iowa borders. 715, then as now, covered the remaining northwestern part. The numbering plan area was first split in 1955, when much of the western portion, including Madison, received area code 608. This configuration remained in place until July 26, 1997, when the northern half of NPA 414, including Green Bay and the Fox River Valley, became numbering plan area 920. The creation of 920 was intended as a long-term solution, but within a year 414 was close to exhaustion once again due to the proliferation of cell phones and pag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detroit
Detroit ( , ) is the List of municipalities in Michigan, most populous city in the U.S. state of Michigan. It is situated on the bank of the Detroit River across from Windsor, Ontario. It had a population of 639,111 at the 2020 United States census, 2020 census, making it the List of United States cities by population, 26th-most populous city in the United States and the largest U.S. city on the Canada–United States border. The Metro Detroit area, home to 4.3 million people, is the second-largest in the Midwestern United States, Midwest after the Chicago metropolitan area and the 14th-largest in the United States. The county seat, seat of Wayne County, Michigan, Wayne County, Detroit is a significant cultural center known for its contributions to music, art, architecture and design, in addition to its historical automotive and industrial background. In 1701, Kingdom of France, Royal French explorers Antoine de la Mothe Cadillac and Alphonse de Tonty founded Fort Pontc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 313
Area code 313 is a telephone area code in the North American Numbering Plan serving Detroit and most of its closest suburbs in Wayne County, Michigan. It includes the enclave cities Hamtramck and Highland Park, as well as Allen Park, Dearborn, Dearborn Heights, Ecorse, the Grosse Pointe communities, Harper Woods, Inkster, Melvindale, Lincoln Park, Redford, River Rouge, and Taylor north of Goddard Road and east of Holland Road. History Area code 313 was assigned as one of the original 86 area codes in October 1947, when it was designated to serve the southeastern quadrant of Michigan, including Metro Detroit, Flint, and the southern part of The Thumb. The rest of the eastern half of the Lower Peninsula was assigned to area code 517. Because of the demand for new telephone service in Detroit's suburbs and neighboring areas, the northern portion, including Detroit's northern suburbs, Flint and the southern Thumb were split off with new area code 810 on 1 December 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
