e for video or other combinations that add up to light pen. 128kbit/s. Videophone terminals are currently becoming available 4. PC videophone, which is a future application that is becoming throughout the world initially in Japan in 1991 and in Europe and available on a PC similar to the standard videophone terminal. elsewhere during 1992. Although still expensive they are in their The picture is now displayed on a standard PC screen just as early days as regard development and prices can be expected to fall any other application in the windows environment. in the future. 44.7.3 Video conferencing terminals 44.8 Broadband ISDN Video conferencing units are already available which support this The specification of a Broadband Integrated Services Digital Net- service at a number of different rates. Originally developed for use work (B-ISDN) is actively being pursued in international standards 44/14 The Integrated Services Digital Network bodies, such as CCITT who adopted accelerated procedures for a 44.8.2 Transfer mode number of recommendations in 1990. In Europe this activity is being led by the European Technical Standards Institute (ETSI) In the 1988 CCITT Recommendations it was agreed that the most whilst in the USA, the American National Standards Institute effective technique for handling broadband services and yet still be (ANSI) is the driving force. (Similar standards bodies in Australia, capable of handling all the narrowband-ISDN services should be a Japan etc. are also contributing to the debate.) Also in Europe the network based upon Asynchronous Transfer Mode (ATM) tech- European Commission are supporting a collaborative research pro- niques. This decision therefore influences the standardisation of not gramme called RACE (Research into Advanced Communications in only switches and interfaces but of the digital hierarchies and Europe) to work towards an Integrated Broadband Communications multiplexing structures. The technique is relatively new and imma- Network. ture although research centres have bee