Negative Positive
Title: Not useful at all
Review: Too many topics, not very related, and unlike erbium amplifiers, the author has no experience, and made no contributions in any of these topics. When I was in fourth grade I (and my classmates) wrote reports by rephrasing World Book Encyclopedia articles. Desurvie is not that bad, but you get the idea. There are good books on broadband access, optical components, networks and cryptography - get one of these books by an experienced practitioner, not a intellectual property functionare (according to his bio.)
Is the review positive or negative? 