Nippon Telegraph & Telephone Corp has developed the heart of a super-small satellite earthstation in conjunction with Canadian start-up International Data Casting Ltd, for use with Integrated Services Digital Network communications systems via high frequency modems, particularly in rural areas: the Canadian company was established only in 1984, and already has relationships with Mitsui Corp and ASCII Corp; NTT is also developing indoor units in conjunction with NEC Corp – ISDN service began between Tokyo, Nagoya and Osaka in April this year, and service is planned to be extended to 25 regions of Japan by the end of this year; it has proved too expensive to set up the facilities in remoter areas with difficult – mountainous topography, but NTT is promising that it will start tackling the problem during 1989.