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4ESS
The No. 4 Electronic Switching System (4ESS) is a class 4 telephone switch, class 4 telephone electronic switching system that was the first digital electronic toll switch introduced by Western Electric for long-distance switching. It was introduced in Chicago, Illinois, Chicago in January 1976, to replace the 4A crossbar switch. The last of the 145 systems in the AT&T Corporation, AT&T network was installed in 1999 in Atlanta. Approximately half of the switches were manufactured in Lisle, Illinois, and the other half in Oklahoma City, Oklahoma. At the time of the Bell System divestiture, most of the 4ESS switches became assets of AT&T as part of the long-distance network, while others remained in the RBOC networks. Over 140 4ESS switches remained in service in the United States in 2007. System architecture The 4ESS Switch is often considered as a switching network and its controlling processor. The major functional equipment areas include: * 1B processor, the 4ESS primary contr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class 4 Telephone Switch
A class-4, or tandem, telephone switch is a U.S. telephone company central office telephone exchange used to interconnect local exchange carrier offices for long distance communications in the public switched telephone network. A class-4 switch does not connect directly to telephones; instead, it connects to other class-4 switches and to class-5 telephone switches. The telephones of service subscribers are wired to class-5 switches. When a call is placed to a telephone that is not on the same class-5 switch as the originating subscriber, the call may be routed through one or more class-4 switches to reach its destination. Etymology ''Tandem'' derives from the Latin adverb ''tandem'' meaning ''at length'', and is used in English to mean a group of two people or machines working together, usually in series. A tandem switch is used to interconnect other switches via trunks. Thus, tandem switches are always part of a series of switches and lines that connect telephone callers to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Electric
The Western Electric Company was an American electrical engineering and manufacturing company officially founded in 1869. A wholly owned subsidiary of American Telephone & Telegraph for most of its lifespan, it served as the primary equipment manufacturer, supplier, and purchasing agent for the Bell System from 1881 to 1984 when it was dismantled. The company was responsible for many technological innovations as well as developments in industrial management. History In 1856, George Shawk, a craftsman and telegraph maker, purchased an electrical engineering business in Cleveland, Ohio. In January, 1869, Shawk had partnered with Enos M. Barton in the former Western Union repair shop of Cleveland, to manufacture burglar, fire alarms, and other electrical items. Both men were former Western Union employees. Shawk, was the Cleveland shop foreman and Barton, was a Rochester, New York telegrapher. During this Shawk and Barton partnership, one customer was an inventor sourcing parts and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3B20D
The 3B series computers are a line of minicomputers produced from the late 1970s by AT&T Computer Systems' Western Electric subsidiary for use with the company's UNIX operating system. The line primarily consists of the models 3B20, 3B5, 3B15, 3B2, and 3B4000. The series is notable for controlling a series of electronic switching systems for telecommunication, for general computing purposes, and for serving as the historical software porting base for commercial UNIX. History The first 3B was installed in Fresno, California at Pacific Bell. Within two years, several hundred were in place throughout the Bell System. Some of the units came with "small, slow hard disks". The general purpose family of 3B computer systems includes the 3B2, 3B5, 3B15, 3B20S, and 3B4000. They run the AT&T UNIX operating system and are named after the successful 3B20D. In 1984, after regulatory constraints were lifted, AT&T introduced the 3B20D, 3B20S, 3B5, and 3B2 to the general computer market, a mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1AESS Switch
The Number One Electronic Switching System (1ESS) was the first large-scale stored program control (SPC) telephone exchange or electronic switching system in the Bell System. It was manufactured by Western Electric and first placed into service in Succasunna, New Jersey, in May 1965. The switching fabric was composed of a reed relay matrix controlled by wire spring relays which in turn were controlled by a central processing unit (CPU). The 1AESS central office switch was a plug compatible, higher capacity upgrade from 1ESS with a faster 1A processor that incorporated the existing instruction set for programming compatibility, and used smaller remreed switches, fewer relays, and featured disk storage. It was in service from 1976 to 2017. Switching fabric The voice switching fabric plan was similar to that of the earlier 5XB switch in being bidirectional and in using the call-back principle. The largest full-access matrix switches (the 12A line grids had partial access) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Earle Vaughan
Henry Earle Vaughan, better known as H. Earle Vaughan, (February 3, 1912 – March 9, 1978) was an American telephony engineer, responsible for system and software design for Bell Laboratories' Electronic Switching System No. 1 ESS, and for planning and development of No. 4 Electronic Switching System for long-distance telephony. Biography In 1928 Vaughan began work in Bell Laboratories, then attended Cooper Union College in New York City, where in 1933 he received a Bachelor of Science degree. Throughout the next decade he worked on a variety of transmission and signaling projects, and in 1944 received the Naval Ordnance Award for his computer work. In 1945 he began research on two experimental switching systems: first the Electronically Controlled Automatic Switching System (ECASS), an experimental system using cold cathode gas tubes, reed switches and a special telephone set, and subsequently the Drum Information Assembler and Dispatcher (DIAD), a magnetic drum system tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common-network Interface Ring
The common-network interface ring (CNI ring) provides common-channel signaling (CCS) functionality on several Alcatel-Lucent SS7 products. It was introduced by Western Electric in the early 1980s but is still used today in all 1AESS and 4ESS, offices, and most of the wireline 5ESS offices. It was designed and manufactured at the combined Bell Labs– WECo location in Columbus, Ohio Columbus () is the state capital and the most populous city in the U.S. state of Ohio. With a 2020 census population of 905,748, it is the 14th-most populous city in the U.S., the second-most populous city in the Midwest, after Chicago, an .... References {{reflist Telephony signals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1ESS Switch
The Number One Electronic Switching System (1ESS) was the first large-scale stored program control (SPC) telephone exchange or electronic switching system in the Bell System. It was manufactured by Western Electric and first placed into service in Succasunna, New Jersey, in May 1965. The switching fabric was composed of a reed relay matrix controlled by wire spring relays which in turn were controlled by a central processing unit (CPU). The 1AESS central office switch was a plug compatible, higher capacity upgrade from 1ESS with a faster 1A processor that incorporated the existing instruction set for programming compatibility, and used smaller remreed switches, fewer relays, and featured disk storage. It was in service from 1976 to 2017. Switching fabric The voice switching fabric plan was similar to that of the earlier 5XB switch in being bidirectional and in using the call-back principle. The largest full-access matrix switches (the 12A line grids had partial access) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crossbar Switch
In electronics and telecommunications, a crossbar switch (cross-point switch, matrix switch) is a collection of switches arranged in a matrix configuration. A crossbar switch has multiple input and output lines that form a crossed pattern of interconnecting lines between which a connection may be established by closing a switch located at each intersection, the elements of the matrix. Originally, a crossbar switch consisted literally of crossing metal bars that provided the input and output paths. Later implementations achieved the same switching topology in solid-state electronics. The crossbar switch is one of the principal telephone exchange architectures, together with a rotary switch, memory switch, and a crossover switch. General properties A crossbar switch is an assembly of individual switches between a set of inputs and a set of outputs. The switches are arranged in a matrix. If the crossbar switch has M inputs and N outputs, then a crossbar has a matrix with ''M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcatel-Lucent
Alcatel–Lucent S.A. () was a French–American global telecommunications equipment company, headquartered in Boulogne-Billancourt, France. It was formed in 2006 by the merger of France-based Alcatel and U.S.-based Lucent, the latter being a successor of AT&T's Western Electric and Bell Labs. In 2014, the Alcatel-Lucent group split into two: Alcatel-Lucent Enterprise, providing enterprise communication services, and Alcatel-Lucent, selling to communications operators. The enterprise business was sold to a Chinese company in the same year, and in 2016 Nokia purchased the rest of Alcatel-Lucent. The company focused on fixed, mobile and converged networking hardware, IP technologies, software and services, with operations in more than 130 countries. It had been named Industry Group Leader for Technology Hardware & Equipment sector in the 2014 Dow Jones Sustainability Indices review and listed in the 2014 Thomson Reuters Top 100 Global Innovators for the 4th consecutive year. Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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