Videophone

A videophone is a telephone with additional video screen. Mobile phones can be used to construct image links.

When a connection between two mutually compatible videophone devices in a mutual visual contact of the interlocutors can be made. If more than two are bonded together, is usually referred to as a video conference system. For the hearing impaired, the phone may not otherwise use, so that the communication with sign language is possible.

Germany

The idea of the video telephone is as old as television. Found before the Second World War in Germany first attempts by a process developed by Georg Oskar Schubert process instead. 1936, the first public television -telephone service between Berlin, Nuremberg and Munich, has been introduced. From public television stations could then call each image. Later, further attempts to establish the video telephony were made, such as in 1985 with the BIGFON project ( Broadband Integrated Glass - Fiber Optical Network ) of the German Federal Post Office, which was later converted to a precursor broadband network VBN in Germany and the 20 largest cities in Germany association. The transfer of the picture and sound was digitally with 140 Mbit / s, in the best TV quality, no compression, circuit-switched and virtually no delays. Large companies such as IBM and Daimler took advantage of this network then for interactive training of staff in their offices. This network was shut down around 1992, from toll- political reasons and because, inter alia, a new in the ITU-T standardized ATM technology should be introduced. ATM was never accepted as a basis for video telephony.

Picture phones were for the analog telephone network, and later the ISDN temporarily still offered with a small display, but had no particular success in the market due to high cost and low image quality. In application studies for the audio- visual communication in the medical field (patient ↔ specialist), in the care of elderly or sick people or deaf people in homes or private homes, these devices but have been well received. Later, a higher bandwidth than ISDN was possible using the new high-speed transmission technology so that with the use of PC, Webcams and appropriate software, the Internet was the basis for video telephony.

Switzerland

BASKOM, a circuit-switched, application-oriented 140-Mbit/s-Versuchsnetz with 30 subscriber connections was put into operation in 1991. It offered two services: video calling ( video telephone in color television quality with direct eye contact ) and a video library retrieval (film retrieval from central moving image storage ).

Developed in 2004, the Mobily Procom GmbH in cooperation with Siemens a videophone for the deaf in Switzerland, the TeleSIP, based on the Internet Protocol. The project was aborted after a field trial again, officially because the software was too error-prone. This software should combine the functions videophone (via webcam), text telephone, live chat and acoustic phone in one device. Competition got Siemens / Procom at this time with the offered by different providers in the area of ​​hearing impaired Video Phone (Model D-Link DVC -1000). This requires, in contrast to TeleSIP not have a computer, but no chat is possible. This product as well as newer products that work mostly by the SIP standard, are now used by a minority of the deaf. The majority used video chat software from established manufacturers, such as Skype.

Mobile phones as devices for video telephony

Since 2005, with a camera -equipped mobile phones offer the opportunity to make a picture phone. This must be present, such as UMTS and suitably equipped terminals, which have a lens on the front side in addition to the standard lens on the rear side of the mobile phone a powerful cellular network. As transmission technology also traditional internet can be used, such as when a WLAN is available; as software can then be used as Skype. Along with the iPhone 4 was introduced by Apple FaceTime. So far, the video telephony on mobile phones but could not prevail.