Technology 1991: telecommunications

Noteworthy trends and occurrences in telecommunication during 1990 are examined. half a dozen countries deregulated their telephone companies to admit competition in the hopes of accelerating technological development. One of the leading technologies to take off was mobile communications, particularly services based on digital transmission. A worldwide standard for the broadband integrated-services digital network (ISDN) was finally accepted, allowing worldwide compatibility for the emerging fiber-optics-based broadband ISDN systems. Meanwhile, narrowband ISDN crossed international borders for the first time, offering transoceanic service. In optical-fiber transmission, the most promising development was erbium-doped optical amplifiers, which are cheaper and simpler for long-distance communications, especially if many signals are to be multiplexed onto one fiber. In addition, investigators demonstrated a simple processor entirely based on optical logic elements and parallel optical connections through free space, which may be another significant step toward an optical computer