Implementing the high performance and high reliability required in und
ersea transmission systems demands careful design, as well as the care
ful selection and management of technology. This paper explores the te
chnology used in undersea systems that support optically amplified rep
eatered applications at rates up to 5 Gbits/s. It provides a brief, hi
gh-level description of a typical undersea system and its subsystems,
then examines each of the subsystems and associated new technologies i
n greater detail.