AT&T Communications, Inc., was a division of the AT&T Corporation that, through 23 subsidiaries, provided interexchange carrier and long-distance telephone services.
History
AT&T Long Lines
The American Telephone and Telegraph Long Lines wire, cable, and microwave radio relay network provided long-distance services for AT&T to its customers. The connection to other countries from the United States began here. By the 1970s, 95% of long-distance and 70% of intercity telephone calls in the United States were carried by AT&T.
Before using microwave relay and coaxial cables, AT&T used open wire lines for long-distance service. In 1911, the system connected New York to Denver. The introduction of repeater towers allowed such connections to reach across North America. Starting in the 1920s, the company increasingly used long-distance coaxial cable and carrier systems.
With improved klystrons and other microwave devices devised during World War II, higher frequencies allowed far more channels on a given link. This allowed a single microwave relay to carry thousands of telephone calls. Bell Labs developed a practical system known as TD-2, produced by Western Electric. The system was designed not only to carry telephone calls, but also television signals, allowing programs to be sent from city to city. Microwaves are line of sight technology, so building such a network required towers built in strings between the endpoints, but this was still much less expensive than stringing the equivalent number of cables between the two points. The first complete system was installed between New York and Chicago and opened on September 1, 1950.
Formal opening of the United States coast-to-coast connection was on August 17, 1951, via AT&T's network control center in New York City. A presidential address from Harry Truman at the San Francisco Peace Conference on September 4, 1951 opened the network, demonstrating coast-to-coast television service. The first regularly scheduled show to use this was Edward R. Murrow's See It Now on November 18, 1951. Later the network allowed events such as American Bandstand and ABC's Monday Night Football to be broadcast live nationally and permitted distribution of regional sports events, such as Saturday football games prior to the adoption of satellite communications in the 1970s.
While coaxial links continued to connect major US cities, the primary links had moved to the microwave systems by the late 1960s.
By the 1980s, alternatives supplemented what was in place.
Long Lines briefly published a periodical, TWX, targeted to companies that used AT&T's equipment and services, particularly TeletypeWriter eXchange, from which it took its name. The periodical was discontinued in 1952.
Direct distance dialing
In 1950, New York City's five boroughs could be dialed directly by subscribers from various communities in New Jersey with the digits '1-1' followed by the seven-digit telephone number. While New York City received the area code 212 when AT&T formulated the first nationwide telephone numbering plan in October 1947, it wouldn't be until 1951 when Englewood, New Jersey, customers would dial their calls to New York City using the prefix 212, as well as other area codes to reach many cities in the nation. New York City's five boroughs also had been dialing northeastern New Jersey as 11+ the two letters and five digits of the New Jersey number.
The use of area code 201 to call New Jersey from New York City only began latter in the 1950s. Other cities in northeastern New Jersey were dialable in 1951 (and for a few years prior) from Englewood by simply dialing the two letters of the exchange name and remaining five digits. In addition to New York City, the Nassau County part of Long Island was dialable from Englewood and Teaneck using area code 516. Also Westchester County, Rockland County, and portions of Orange and Putnam Counties were also dialable from Englewood and Teaneck in 1951 using area code 914.
Early in the 20th century, the telephone companies organized a "Separations and Settlements" process by which Long Lines and the local companies divided the revenues of long-distance calls according to their respective costs. The mid-century advent of microwave and other high capacity systems dramatically cut the cost of long-haul operations, but pricing did not decline proportionally. Rather, the local fraction of revenue-sharing rose to subsidize local service.
AT&T Communications
AT&T Communications became one of the three core sales units of AT&T after reorganization of assets.