The US army's first portable telemedicine unit was built in 1993 and comprised a 'ruggedized' videoconferencing unit. The unit was initially used in the United Nations' operations in Macedonia in February 1994 and subsequently in support of the Mobile Army Surgical Hospitals in Haiti, but its dimensions made it suitable only for locations where a move at short notice was unlikely. The second portable telemedicine unit comprised a PC linked to an Inmarsat B earth station through a modern. The unit allowed videoconferencing at 64 kbit/s. Three and a half years of clinical experience with both units has shown this to be quite adequate for the majority of clinical telemedicine. Portable telemedicine units have been a major benefit to medical commanders in the field.