1968 First 911 call is made On February 16 the first 911 call is made in Haleyville, Alabama. Legislation calling for a single nationwide phone number for citizens to use to report fires and medical emergencies was passed by Congress in 1967, and in January 1968 AT&T announced plans to put such a system into place. An independent company, Alabama Telephone, scrambled to build its own system and succeeded in beating AT&T to the punch. The numbers 911 were chosen because they were easy to remember and did not include three digits already in use in a U.S. or Canadian area code. In Britain a national emergency number—999—had been in place since the late 1930s. 1968 First 911 call is made On February 16 the first 911 call is made in Haleyville, Alabama. Legislation calling for a single nationwide phone number for citizens to use to report fires and medical emergencies was passed by Congress in 1967, and in January 1968 AT&T announced plans to put such a system into place. An independent company, Alabama Telephone, scrambled to build its own system and succeeded in beating AT&T to the punch. The numbers 911 were chosen because they were easy to remember and did not include three digits already in use in a U.S. or Canadian area code. In Britain a national emergency number—999—had been in place since the late 1930s. 1973 First portable cell phone call is made The first portable cell phone call is made by Martin Cooper of Motorola to his research rival at Bell Labs, Joel Engel. Although mobile phones had been used in cars since the mid-1940s, Cooper’s was the first one invented for truly portable use. He and his team are awarded a patent in 1975. 1975 U.S. military begins using fiber optics The U.S. military begins using fiber optics to improve communications systems when the navy installs a fiber-optic telephone link on the USS Little Rock. Used to transmit data modulated into light waves, the specially designed bundles of transparent glass fibers are thinner and lighter than metal cables, have greater bandwidth, and can transmit data digitally while being less susceptible to interference. The first commercial applications come in 1977 when AT&T and GTE install fiber-optic telephone systems in Chicago and Boston. By 1988 and 1989, fiber-optic cables are carrying telephone calls across the Atlantic and Pacific Oceans. 1976 Common channel interoffice signaling AT&T introduces common channel interoffice signaling, a protocol that allows software-controlled, networked computers or switches to communicate with each other using a band other than those used for voice traffic. Basically a dedicated trunk, the network separates signaling functions from the voice path, checks the continuity of the circuit, and then relays the information.
1978 Public tests of a new cellular phone system Public tests of a new cellular phone system begin in Chicago, with more than 2,000 trial customers and mobile phone sets. The system, constructed by AT&T and Bell Labs, includes a group of small, low-powered transmission towers, each covering an area a few miles in radius. That test is followed by a 1981 trial in the Washington-Baltimore area by Motorola and the American Radio Telephone Service. The Federal Communications Commission officially approves commercial cellular phone service in 1982, and by the late 1980s commercial service is available in most of the United States. 1978 Public tests of a new cellular phone system Public tests of a new cellular phone system begin in Chicago, with more than 2,000 trial customers and mobile phone sets. The system, constructed by AT&T and Bell Labs, includes a group of small, low-powered transmission towers, each covering an area a few miles in radius. That test is followed by a 1981 trial in the Washington-Baltimore area by Motorola and the American Radio Telephone Service. The Federal Communications Commission officially approves commercial cellular phone service in 1982, and by the late 1980s commercial service is available in most of the United States. 1990s (Mid) Voice Over Internet Protocols The advent of Voice Over Internet Protocols (VoIP)—methods of allowing people to make voice calls over the Internet on packet-switched routes— starts to gain ground as PC users find they can lower the cost of their long-distance calls. VoIP technology is also useful as a platform that enables voice interactions on devices such as PCs, mobile handhelds, and other devices where voice communication is an important feature. 2000 100 million cellular telephone subscribers The number of cellular telephone subscribers in the United States grows to 100 million, from 25,000 in 1984. Similar growth occurs in other countries as well, and as phones shrink to the size of a deck of cards, an increasingly mobile society uses them not only for calling but also to access the Internet, organize schedules, take photographs, and record moving images.
Which of the appliances in your home would be the hardest to live without? The most frequent answer to that question in a recent survey was the refrigerator. Over the course of the 20th century, this onetime luxury became an indispensable feature of the American home, a mainstay in more than 99.5 percent of the nation's family kitchens by century's end. Which of the appliances in your home would be the hardest to live without? The most frequent answer to that question in a recent survey was the refrigerator. Over the course of the 20th century, this onetime luxury became an indispensable feature of the American home, a mainstay in more than 99.5 percent of the nation's family kitchens by century's end. But the engineering principle on which it is based, mechanical refrigeration, has had even more far-reaching effects, through both refrigeration itself and its close cousin, air conditioning. Taken together, these cooling technologies have altered some of our most fundamental patterns of living. Our daily chores are different. What we eat and how we prepare food have both changed. The kinds of buildings we live and work in and even where we choose to live across the whole length and breadth of the United States all changed as a result of 20th-century expertise at keeping things cool.
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