Fiber optics: Poised to displace satellites: Expansion of fiber-optic cable networks will lead to the creation of new communication services and may limit the role of satellites

The advantages offered by fiber-optic systems are summarized., These include low susceptibility to electromagnetic interference, absence of electromagnetic radiation leaks, and absence of noticeable delay in signal propagation. Attention is then given to recent improvements in satellite communications, including delay `compensators´ and forward error-correcting codes. Work being done to overcome the problem of modal dispersion in fiber optics is surveyed. The switching advances expected in fiber-optic networks are also described.