The digital versatile disc (DVD) is a new optical recording medium wit
h a storage capacity seven times higher than the conventional compact
disc (CD). The major part of the capacity increase is achieved by the
use of optics, shorter laser wavelength, and larger numerical aperture
, which reduces the spot diameter by a factor of 1.65. The track forme
d by the recorded pits and lands, as well as the track pitch, can be r
educed by the same factor. The storage capacity is further increased b
y a complete redesign of the logical format of the disc, including a m
ore powerful error correction and recording code. The system requireme
nts of the DVD and the related channel coding are outlined in this pap
er.