Telecommunication is defined as the remote transmission of information with means based electronics and computer. This term has a broader meaning than its official equivalent "electronic communication" sense. They differ from the position which transmits information or objects in a physical form.
In the beginnings of modern telecommunications, inventors like Antonio Meucci, Alexander Graham Bell and Guglielmo Marconi developed communication devices such as the telegraph, telephone or radio. They have revolutionized the traditional means such as pavilions or optical telegraph Chappe.
Currently, telecommunications generally involve the use of electronic equipment associated with analog or digital networks such as fixed or mobile telephone, radio, television or the computer. They are also an important part of the economy and are the subject of regulations globally.
Telecommunications is a place of convergence and interaction between different scientific disciplines and technologies.
Mathematics and particularly applied mathematics are the foundation of the development of signal processing theories (modernization of telecommunications), cryptography (security trade), the information theory and digital.
Physical enabled through mathematical development to build the theory of electromagnetism. then appeared the first crystal sets, then the empty tubes, semiconductors and opto-electronics, which are based on electronics. Electromagnetism, especially the study of propagation phenomena, to model the propagation of waves through a channel, whether wired (coaxial, optical fiber ...) or wireless (radio propagation). Similarly, the invention of the laser physicists opened the way for modern communications by optical fibers (Nobel Prize in Physics 2008)
Chemistry, through chemical refining process, has reduced the weight and extend battery life, allowing the use of portable telecommunication devices.
The fundamental and applied computing in turn revolutionized the world of communication remotely by the development of programming languages and computer programs (software engineering) associated with microelectronics.
The transport of voice telephony, was the first advanced telecommunications, just after the first telegraph. The phone is the device used to hold a two-way conversation with a distant person. It is used in private, to keep in touch with loved ones or professional, to exchange oral information without having to physically meet.
Telephony based on the telephone network also allows for more advanced services such as voicemail, conference calling and voice services. The phone line also serves as a solution to Internet access, first with a low bandwidth modem and broadband through ADSL.
The radio, that is to say the wireless remote communication, was first applied to maritime communications to increase security and military since World War before becoming a popular medium with the TSF. The radio is still the main means of communication for air traffic control, maritime links with the marine radio and security links (police, rescue). It is also the main business of ham radio.
Broadcasting is the distribution of programs from a transmitter to listeners equipped with a receiver. First by low frequency amplitude modulation (GO) and medium frequency (MW) and frequency modulation in VHF, it evolves into the digital radio broadcast by satellite or terrestrial radio.
The mobile phone provides the ability to wirelessly or through a terrestrial solution based on radio coverage areas of base stations or by satellite. The development of this means of communication is a phenomenon of remarkable society of the late twentieth century. The gesture to call the street becomes commonplace, so much worry about its health risks and create a special language, texting. Access to the Internet and television is already easy on the latest phones of generations (smartphones).
The transmission of still images Dial back to belinograph, and is still used under the abbreviated name of fax as exchange of photocopied pages, commercial or technical documents. The RADIOFACSIMILE that can transmit images via radio is used primarily for disseminating weather maps, either directly from observation satellites, is transmitted to the ships or airfields.
After the telephone and radio, television is present in every home. Forests of yagi antennas and satellite dishes have invaded cities, satellite channels, analog and digital first multiplied the national and international programs.
Modern receivers plasma or LCD provide high quality images and digital terrestrial further increasing user choice.
Transmitting simultaneous images to a telephony link is possible through videoconferencing using high-speed dedicated channels, by analogue slow scan transmission or SSTV immortalized by the first steps on the moon, and digital new techniques , webcam on the internet or last generation mobile phone.
Preparation and presentation in Paris on 29 October 2001, the first transmission of digital cinema satellite in Europe of a cinematic feature by Bernard and Philippe Pauchon Dinant.
Telegraph is the ancestor data transmissions and the first application of telecommunications: transmitting characters, so a message, for optical signals, and then on a line and by radio (telegraphy). The teletype then radioteletype have automated.
A computer network is a set of equipment connected together to exchange information. Although the Internet is not the only computer network system, it has almost become synonymous. The Internet structure is complex and can be separated into several parts:
Telemetry, as terrestrial hydrological or meteorological or space such as Meteosat images or those of distant planetary probes, enables the monitoring of industrial plants, increase our knowledge of the environment, climate or the universe.
The remote control, the simplest as home automation or HiFi and video, or more complex such as the Mars robot, is the wireless remote control, optical or radio, generally coupled to the telemetry.
The radio signal may contain other information, such as parameters for the position calculations, the universal time, detection targets or terrain mapping.
Although the radar is not strictly a communication system, but remote sensing, techniques combine microwave, signal processing, radio, and can be related to the world of telecommunications.
Originally developed for the detection of air raids, radar was quickly installed on ships and airplanes.
From military and civilian first, air and maritime controls intensively use radar for safety. Finally the weather radar can map the rain and clouds, including from observation satellites.
The navigation enabled, in the early days of radio, to help the maritime and air navigation, through the finding and radio beacons and hyperbolic systems such as LORAN. Satellite navigation systems like GPS have become a vehicle running gear, pending the development of the Galileo future.
The automatic identification systems such as AIS and obstacle detection improve the safety of navigation.
The spread of universal time and time signal is integrated to the current GPS navigation signals, but has long been a specific service to help celestial navigation, or scientific synchronization by HF emissions as WWV or BF as the emitter Allouis or DCF77.
For their telecommunications, military use discretion methods such as frequency hopping and encryption, on radiotelephone HF and VHF networks, or dedicated satellites like Syracuse. Governments also use radio technology for the purpose of signals intelligence as the Echelon satellite system listening or jamming of radio systems and against measures.
Source : Wikipedia
