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Class 5 Telephone Switch
{{No footnotes, date=August 2008 A class-5 telephone switch is a telephone exchange in the public switched telephone network (PSTN) that directly serves subscribers and manages subscriber calling features. Class-5 services include basic dial-tone, calling features, and additional digital and data services to subscribers connected to a local loop. Function A class 5 switch provides telephone service to end customers locally in the exchange area, and thus it is concerned with "subscriber type" activities: generation of dial-tone and other "comfort noises"; handling of network services such as advice of duration and charge etc. Specifically, a class-5 switch provides dial tone, local switching and access to the rest of the network. Class-4 switches do not provide subscriber lines, their role is to route calls between other switches. Typically a class-5 switch serves an area of a city, an individual town, or several villages and could serve from several hundred to 100,000 subscri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
A telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers. In historical perspective, telecommunication terms have been used with different semantics over time. The term ''telephone exchange'' is often used synonymously with ''central office'', a Bell System term. Often, a ''central office'' is defined as a building used to house the inside plant equipment of potentially several telephone exchanges, each serving a certain geographical area. Such an area has also been referred to as the exchange or exchange area. In North America, a central office location may also be identified as a ''wire center'', designating a facility to which a telephone is connected and obtains dial tone. For business and billing purposes, telecommunication carriers defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panel Switch
The Panel Machine Switching System is a type of automatic telephone exchange for urban service that was used in the Bell System in the United States for seven decades. The first semi-mechanical types of this design were installed in 1915 in Newark, New Jersey, and the last were retired in the same city in 1983. The Panel switch was named for its tall panels which consisted of layered strips of terminals. Between each strip was placed an insulating layer, which kept each metal strip electrically isolated from the ones above and below. These terminals were arranged in ''banks'', five of which occupied an average selector frame. Each bank contained 100 sets of terminals, for a total of 500 sets of terminals per frame. At the bottom, the frame had two electric motors to drive sixty selectors up and down by electromagnetically controlled clutches. As calls were completed through the system, selectors moved vertically over the sets of terminals until they reached the desired location, at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSTN Network Topology
PSTN network topology is the switching network topology of a telephone network connected to the public switched telephone network (PSTN). In the United States and Canada, the Bell System network topology was the switching system hierarchy implemented and operated from c. 1930 to the 1980s for the purpose of integrating the diverse array of local telephone companies and telephone numbering plans to achieve nationwide Direct Distance Dialing (DDD) by telephone subscribers. It was the precursor of the world-wide interconnected public switched telephone network (PSTN) and originated in the efforts of the General Toll Switching Plan that by 1929 formulated the technical infrastructure and the operating principles for connecting long-distance telephone calls in North America. The ideas were first developed in the Bell System in the United States, but were soon adopted by other countries where telephone companies were facing similar issues, even when servicing smaller geographic areas. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Community Dial Office
A "Community Dial Office" (CDO) was a small Class 5 telephone exchange in a rural area. These most often provided capacity for 1,000 or fewer customers and were designed for unattended operation. CDOs could be step by step, all relay or crossbar. Many offices provided four-digit local dialling to small rural communities where a call outside the local exchange was long distance. Initial deployments were based on step-by-step equipment such as the Western Electric 350A (first deployed on May 27, 1928, in Arcadia, California) and its successor models 360A, 355A and 356A. These switches had some design similarities to No. 1 step-by-step systems already in use in large offices (10,000 subscribers or more) but were of a simpler design (line finders would only need to scan hundreds of lines instead of the thousands in use in the cities) and not designed for expandability. Any operator assistance or toll call billing for these unattended stations was handled remotely at a larger exchang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Over IP
Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of speech, voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet telephony, broadband telephony, and broadband phone service specifically refer to the provisioning of communications services (voice, fax, Short Message Service, SMS, voice-messaging) over the Internet, rather than via the public switched telephone network (PSTN), also known as plain old telephone service (POTS). Overview The steps and principles involved in originating VoIP telephone calls are similar to traditional digital telephony and involve signaling, channel setup, digitization of the analog voice signals, and encoding. Instead of being transmitted over a circuit-switched network, the digital information is packetized and transmission occurs as IP packets over a packet-switched network. They transport media streams using spec ... [...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] |
EWSD
The Elektronisches Wählsystem Digital (EWSD), translated to ''Electronic Digital Switching System'' in English, is a widely installed German telephone exchange system, originally introduced in 1975 by Siemens AG, but discontinued in 2017. EWSD can operate as a local end-office switch, a tandem switch, or in a combined configuration for landline or mobile telephone service. Siemens claims that EWSD switches perform switching for over 160 million subscriber lines in more than one hundred countries. History EWSD was introduced in 1975 as a successor of the EWSA (''Elektronisches Wählsystem Analog''), which was using analogue technology. DeTeWe bought its first EWSD under license in 1985 for remote switching. Bosch built its first EWSD as a local exchange in 1986. Deutsche Telekom, formerly Deutsche Bundespost, the largest German telephone company, uses EWSD and System 12 (Alcatel), the former more than the latter. In 2007, Siemens AG and Nokia Corporation jointly formed a new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AXE Telephone Exchange
The AXE telephone exchange is a product line of circuit switched digital telephone exchanges manufactured by Ericsson, a Swedish telecom company. It was developed in 1974 by Ellemtel, a research and development subsidiary of Ericsson and Televerket. The first system was deployed in 1976. AXE is not an acronym, but an Ericsson product code. The AXE is the digital successor to the AKE analogue telephone exchange and ARF/ARM family of crossbar switches. The design is modular with an APZ dual processor running in sync mode, an APT switching part and an APG I/O part. It is used for connecting local landlines, operating mobile networks ( TDMA, GSM, CDMA, W-CDMA, PDC), international telephony traffic and signaling. AXE based equipment are being used as BSC/TRC, MSC, HLR, SCP, FNR, TSC, STP and wireline nodes. The brain of the AXE system is a dual processor system called APZ. It runs in parallel sync mode making it fault redundant. The family of APZs started with APZ 210 03 in 1976; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GTD-5 EAX
The GTD-5 EAX (General Telephone Digital Number 5 Electronic Automatic Exchange) is the Class 5 telephone switch developed by GTE Automatic Electric Laboratories. This digital central office telephone circuit switching system is used in the former GTE service areas and by many smaller telecommunications service providers. History The GTD-5 EAX first appeared in Banning, California on June 26, 1982, slowly replacing the electromechanical systems still in use in the independent switch market at that time. The GTD-5 EAX was also used as a Class 4 telephone switch or as a mixed Class 4/5 in markets too small for a GTD-3 EAX or 4ESS switch. The GTD-5 EAX was also exported internationally, and manufactured outside of the U.S. under license, primarily in Canada, Belgium and Italy. By 1988, it had 4% of the worldwide switching market, with an installed base of 11,000,000 subscriber lines. GTE Automatic Electric Laboratories became GTE Network Systems and later GTE Communication Systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Multiplex System
Digital Multiplex System (DMS) is the name shared among several different telephony product lines from Nortel Networks for wireline and wireless operators. Among them are the DMS-1 (originally named the DMS-256) Rural/Urban digital loop carrier, the DMS-10 telephone switch, the DMS SuperNode family of telephone switches (DMS-100, DMS-200, DMS-250, DMS-300, DMS-500, DMS-GSP, DMS-MSC, DMS-MTX), and the S/DMS optical transmission system. Exploratory development on the technology began at Northern Telecom's Bell Northern Research Labs in Ottawa, Ontario in 1971. The first Class 5 switch, the DMS-10, began service on 21 October 1977 in Fort White, Florida and the first toll switch (Class 4), the DMS-200, entered service in 1979 in Ottawa. The DMS-10 was the first commercially successful Class 5 digital switch in the North American market and had a profound impact on the industry. Of the numerous digital switching products introduced in the North American telephone market in the la ... [...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) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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