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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 n ... [...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 n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
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 def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CHILL
In computing, CHILL (an acronym for CCITT High Level Language) is a procedural programming language designed for use in telecommunication switches (the hardware used inside telephone exchanges). The language is still used for legacy systems in some telecommunication companies and for signal box programming. The CHILL language is similar in size and complexity to the original Ada language. The first specification of the CHILL language was published in 1980, a few years before Ada. ITU provides a standard CHILL compiler. A free CHILL compiler was bundled with GCC up to version 2.95, however, was removed from later versions. An object-oriented version, called Object CHILL, was developed also. ITU is responsible for the CHILL standard, known as ITU-T Rec. Z.200. The equivalent ISO standard is ISO/IEC 9496:2003. (The text of the two documents is the same). In late 1999 CCITT stopped maintaining the CHILL standard. CHILL was used in systems of Alcatel System 12 and Siemens E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication Software
Communication software is used to provide remote access to systems and exchange files and messages in text, audio and/or video formats between different computers or users. This includes terminal emulators, file transfer programs, chat and instant messaging programs, as well as similar functionality integrated within MUDs. The term is also applied to software operating a bulletin board system, but seldom to that operating a computer network or Stored Program Control exchange. History E-mail was introduced in the early 1960's as a way for multiple users of a time-sharing mainframe computer to communicate. Basic text chat functionality has existed on multi-user computer systems and bulletin board systems since the early 1970s. In the 1980s, a terminal emulator was a piece of software necessary to log into mainframes and thus access e-mail. Prior to the rise of the Internet, computer files were exchanged over dialup lines, requiring ways to send binary files over communication ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Busy Hour Call Attempts
In telecommunications, busy-hour call attempts (BHCA) is a teletraffic engineering measurement used to evaluate and plan capacity for telephone networks. BHCA is the number of telephone calls attempted at the sliding 60-minute period during which occurs the maximum total traffic load in a given 24-hour period (BHCA), and the higher the BHCA, the higher the stress on the network processors. BHCA is not to be confused with busy hour call completion (BHCC) which measures the throughput capacity of the network. If a bottleneck in the network exists with a capacity lower than the estimated BHCA, then congestion will occur resulting in many failed calls and customer dissatisfaction. BHCA is usually used when planning telephone switching capacities and frequently goes side by side with the Erlang unit capacity calculation. As an example, a telephone exchange with a capacity of one million BHCA is estimated to handle 250,000 subscribers. The overall calculation is more complex however ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E And M Signalling
E and M signaling is a type of supervisory line signaling that uses DC signals on separate leads, called the "E" lead and "M" lead, traditionally used in the telecommunications industry between telephone switches. Various mnemonic names have been used to memorize these letters, such as ''Ear'' and ''Mouth'', the most common variation. E&M was originally developed for signaling between PABXs in different geographic locations over an analog private circuit. The protocol was later extended for use on digital carrier system with Channel Associated Signaling (CAS). Signaling units and trunk circuits The E&M standards were initially developed by Bell Labs and extended by national PTT administrations. The standard defines two sides of the interface, the trunk circuit and the signaling unit. The trunk circuit is normally the side to which the PABX is connected. The signaling unit is the special modem that converts the DC signaling protocol into tones that could be transmitted over a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R2 Signalling
Signalling System R2 is a signalling protocol for telecommunications that was in use from the 1960s mostly in Europe, and later also in Latin America, Asia, and Australia, to convey exchange information between two telephone switching systems for establishing a telephone call via a telephone trunk.ITU-T Recommendation Q.400-Q.490 - Specifications of Signalling System R2 It is suitable for signaling on analog as well as digital circuits. R2 signaling specifications were first published by the International Telegraph and Telephone Consultative Committee (CCITT) in ITU White Book Volume VI of 1969,IVth Plenary Assembly (Mar Del Plata, 23 September-25 October 1968), White Book Volume VI, ''Telephone Signaling and Switching'', Recommendations Series Q, ITU 1969. and are maintained by the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signalling System No
In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The '' IEEE Transactions on Signal Processing'' includes audio, video, speech, image, sonar, and radar as examples of signal. A signal may also be defined as observable change in a quantity over space or time (a time series), even if it does not carry information. In nature, signals can be actions done by an organism to alert other organisms, ranging from the release of plant chemicals to warn nearby plants of a predator, to sounds or motions made by animals to alert other animals of food. Signaling occurs in all organisms even at cellular levels, with cell signaling. Signaling theory, in evolutionary biology, proposes that a substantial driver for evolution is the ability of animals to communicate with each other by developing ways of signaling. In human engineering, signals are ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCM30
{{unreferenced, date=August 2009 The pulse-code modulation (PCM) technology was patented and developed in France in 1938, but could not be used because suitable technology was not available until World War II. This came about with the arrival of digital systems in the 1960s, when improving the performance of communications networks became a real possibility. However, this technology was not completely adopted until the mid-1970s, due to the large amount of analog systems already in place and the high cost of digital systems, as semiconductors were very expensive. PCM’s initial goal was that of converting an analog voice telephone channel into a digital one based on the sampling theorem. PCM30 describes an application of pulse-code modulation (PCM) in which 30 telephony analog signals are binary coded into a digital signal stream. The term is used today mostly as a synonym for the encoding of 30 channels each with a signalling rate of 64-kbit/s. This rate is also used in the firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DTMF
Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed in the Bell System in the United States, and became known under the trademark Touch-Tone for use in push-button telephones supplied to telephone customers, starting in 1963. DTMF is standardized as ITU-T Recommendation Q.23. It is also known in the UK as ''MF4''. The Touch-Tone system using a telephone keypad gradually replaced the use of rotary dial and has become the industry standard for landline and mobile service. Other multi-frequency systems are used for internal signaling within the telephone network. Multifrequency signaling Before the development of DTMF, telephone numbers were dialed by users with a loop-disconnect (LD) signaling, more commonly known as pulse dialing (dial pulse, DP) in the United States. It functions by i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BORSCHT
Borscht () is a sour soup common in Eastern Europe and Northern Asia. In English, the word "borscht" is most often associated with the soup's variant of Ukrainian origin, made with red beetroots as one of the main ingredients, which give the dish its distinctive red color. The same name, however, is also used for a wide selection of sour-tasting soups without beetroots, such as sorrel-based green borscht, rye-based white borscht, and cabbage borscht. Borscht derives from an ancient soup originally cooked from pickled stems, leaves and umbels of common hogweed (''Heracleum sphondylium''), a herbaceous plant growing in damp meadows, which lent the dish its Slavic name. With time, it evolved into a diverse array of tart soups, among which the Ukrainian beet-based red borscht has become the most popular. It is typically made by combining meat or bone stock with sautéed vegetables, which – as well as beetroots – usually include cabbage, carrots, onions, potat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V5 Interface
V5 is a family of telephone network protocols defined by ETSI which allow communications between the telephone exchange, also known in the specifications as the local exchange (LE), and the local loop. With potentially thousands of subscribers connected to the LE there is the problem of physically managing thousands of wires out to the local subscribers (and the costs associated with that). Prior to the specification of V5 the manufacturers of exchange equipment had proprietary solutions to the problem. These solutions did not inter-operate and meant being tied into a single manufacturer's method at each exchange. V5 provided a standard set of protocols from the subscriber to the LE. The AN (or Access Network) was defined as a reference point. Signalling between this point and the LE was standardised and therefore allowed a multiple vendor solution, provided the specifications were followed. This resulted in a single link (or in the case of V5.2 multiple links) from the AN to the LE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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