Telecommunication

Telecommunications ( τηλέ ancient Greek, away ' and Latin communicare, make together ', ' notify ') or Telecommunications, any exchange of information over a certain distance away. This can be done through different ways: visually ( zBRauchzeichen, flags, heliograph ), by sound (siren, Hunting Horn ), by radio or via the cable network. Especially among the latter two one understands today's telecom Mika Transportation. The former two (optical and acoustic communication ) are used since antiquity.

Definition and delimitation

The foreign word for " telecommunications " belonging German word is telecommunications. However, it is used since the mid- 1990s, practically only to military facilities and civil protection ( civil protection is recently often of " Information and Communication" (ICT ), spoken) and is almost completely disappeared in the spoken language, as especially the use in this area operating companies, the word " telecommunications ".

In the strict sense is understood as a data exchange using electrical engineering, electronics, radio engineering and other transmission technology of modern telecommunications today. The first telecommunications services in this sense were called telegraphy ( teletype ) and telephony, also remote signaling. Before the advent of computers, there were already designated as telecontrol data transmission services to control plants.

" Telecommunications is the technical process of sending, transmitting and receiving of signals by means of telecommunications; 'For the purposes of this definition also are therefore also radio and television ( analog and digital ), fax, mobile telephony and the Internet and esp. examples under the also by the German legislature defined in the telecommunications Act and used in other legal norms notion of telecommunications.

Telecommunication systems are " technical equipment or systems that send messages identifiable as electromagnetic or optical signals that carry, convey, receive, control or can control. " Telecommunications facilities are now a fundamental part of the infrastructure. For this reason, in order to avoid spatial disparities their provision a joint task of spatial development (ie, in practice, a state task). Since the beginning of liberalization ( in Germany since 1998 ) Telecommunications services are provided in competition, universal service is ensured by a universal service obligation.

History and Milestones

• Since prehistoric time: smoke signals
• 5th century BC: Use of Fackeltelegrafie in the Peloponnesian War
• 1816: Francis Ronalds ( London) developed an electric telegraph and sends messages over eight miles.
• 1843 Alexander Bain receives a patent for the electro- telegraphic image decomposition.
• 1848 FC Backwell builds a " copying telegraph " after Bains principle of the image line by line scanning.
• 1861: The German teacher Philipp Reis presents an apparatus similar to today's telephone for voice transmission to the public.
• 1862 transmits Giovanni Caselli simple drawings by wire from Amiens to Paris.
• 1873 Willoughby Smith can prove that the electrical resistance of selenium is light-dependent, his colleague Joseph May uses the element for transmission in telegraphy.
• 1875 Werner von Siemens describes a photocell of selenium. George B. Carey has the idea to transfer images with the help of an array of selenium photocells ( until 1909 is implemented ).
• 1876 ​​: the living in the U.S. Scots Alexander Graham Bell is granted a patent for the first phone.
• 1877: By order of the Postmaster General Heinrich von Stephan, the first regular telephone service is operated.
• 1881: The first Berlin telephone exchange opened with eight participants. Shelford Bidwell builds the "Tele Photograph". In Paris, presented for the first time: the Theatrophon opera and theater performances rendered over the phone.
• 1895: Ferdinand Schneider demonstrated wireless telegraphy
• 1896: Patent of Guglielmo Marconi
• 1906: The first submarine telephone cable is laid in Lake Constance.
• 1908: On July 10, the first public automatic exchange in Europe is put into operation in Hildesheim.
• 1923 in the area around Weilheim of IDD is put into operation
• 1935: the first carrier frequency transmission devices are used on cable lines
• 1936: After tests, the automatic time announcement is finally installed in several cities
• 1950: The German postal service was founded with 1.2 million phone customers
• 1970: the first time a direct dial to America is possible
• 1987: ISDN starts with 750 testers
• 1989: Postal Reform in Germany
• 1994: Postal Reform in Germany
• 1996: Postal Reform III in Germany
• 1996: In the U.S., the deregulation of the telecommunications market is set in motion by the Telecommunications Act.
• 2001: with a single fiber-optic cable, more than 10 terabits transferred per second (15 million ISDN channels in parallel)

Worldwide capacity

The effective exchange worldwide capacity information about bidirectional telecommunication networks was 281 ( optimally compressed ) petabytes in 1986, and in 2007 to 65 ( optimally compressed ) exabytes estimated (or 65 000 petabytes ). This is an average growth rate of 28% per year, and corresponds to the informational equivalent of 2 newspaper pages per person per day in 1986, and 6 all newspapers per person per day in 2007.

Telecommunications technology

TAE stands for telecommunications terminal unit and is used in Germany junction box on telecommunications lines. Other connections: RJ-Stecker/Buchsen or WE-Stecker/Buchsen ( Western plug), also known as UAE for universal connector unit. Even for ISDN and DSL the telephone socket is used as a transfer interface. With other providers, this interface may not be disclosed and a forced installation of the provider equipment must be used.

Is analogous to the transmission of the signals in the sine wave output, for example, generated by the language transmitted in electrical form in the sound waves back. ( Language → → conduction → Speakers → microphone sound wave ). Use modulators and demodulators (modems ) are used. Modem connections are available with up to 56 kbit / s data transfer rate in Germany.

ISDN is the acronym for Integrated Services Digital Network and is the international standard for a digital telecommunications network. Through this network, different services such as telex ( Telex ), teletext, Datex -L ( circuit-switched data transmission), Datex -P ( packet switched data transmission ) and telephone are transmitted and communicated. ISDN connections are 64 kbit / s data transfer rate in Germany offered. At a base port capacity can be doubled by channel bundling. A Primärmulitplexanschluss (30 B channels bundled) has a capacity of 2 Mbit / s. In downstream and upstream

About the Digital Subscriber Line (DSL, English for Digital Subscriber Line ) can send data with a high transfer rate and received ( 1,000 kbit / s to 500 Mbit / s). The different DSL variants (Digital Subscriber Line) all use the existing phone line as customer access, so a single twisted copper pair.

ADSL or ADSL 2 , the asymmetric digital subscriber line, the provision of transmission capacity allows asymmetrical, that the transmission speed in the downstream ( 1.5 to 16 Mbit / s ) is higher than in the upstream ( 16-768 kbit / s). Using an upstream switch, the " Splitter", the phone service is disconnected while on the copper line from the high bit-rate data applications, so that the line can be used in parallel for data transmission.

The fastest asymmetric DSL variant is VDSL (Very High Speed ​​Digital Subscriber Line) with transmission rates of 12-52 Mbit / s downstream and upstream from 1.5 to 2.3 Mbit / s network connection area over a copper pair. However, the transfer is only possible for relatively short transmission distances. The VDSL technology has been specially developed for use in hybrid Glasfaser-/Kupferkabelnetzen, as a complement to ADSL and SDSL in the connection area of the local exchange on the street cabinet to the wall jack.

Identical transfer rate in both directions ( symmetrically ) between 2 and now 20 Mbit / s enables SDSL ( Symmetric Digital Subscriber Line). Since the upstream and downstream occur simultaneously and each with the same, full speed, the symmetrical Internet particularly for companies that transmit with customers or partners large amounts of data or run their own server is. The voice traffic transmission rates 24-240 simultaneous calls correspond.

Economy

For telecommunications companies, a distinction between the operators of telecommunications networks (carriers), providers of services - the so-called service providers - and manufacturers of telecommunications solutions, which are referred to as a supplier or suppliers.

The ten largest telecommunications companies in the world ( by sales, as of 2011):

The largest supplier of telecommunications companies are (worldwide by revenue in 2008):

• Ericsson
• Nokia Solutions and Networks (formerly Nokia Siemens Networks )
• Cisco
• Huawei
• Alcatel- Lucent
• ZTE

Telecommunication costs

What is the Federal Network Agency reported that spending on telecommunications services from the perspective of households fell from an annual average in 2008 compared to 2007, lower by 3.3 percent. Domestic phone calls to German landlines cost early 2009, only one-twentieth compared to 1997. Mobile calls cost 2008 an average of 2.3 percent less than in 2007.

Since the early 1990s, the so-called value-added services (area code 0190 and 0900) and shared -cost services are available ( code 0180 ) are available in the fixed network. Here, the cost of special telephone and other services beyond the normal billing the caller will be handled (see also Audiotex, call center)