Optical fiber fundamentals on Gpon

By: dslam.biz
Advantages of fiber

Extremely high bandwidth
Smaller-diameter, lighter-weight cables
Lack of crosstalk between parallel fibers
Immunity to inductive interference
High-quality transmission
Low installation and operating costs

Extremely high bandwidth
• Fiber today has bandwidth capability theoretically in excess of 10Ghz and attenuations
less than 0.3 db for a kilometer of fiber.
• The limits on transmission speed and distance today lies largely with the laser, receiver
and multiplexing electronics.
• With the future advent of stable narrow line single-mode lasers and coherent optics, 10
to 100 Gb/s transmission is possible.
> Smaller diameter – lighter weight cables
• Even when fibers are covered with protective coatings, they still are much smaller and
lighter than equivalent copper cables.
> Negligible crosstalk
• In conventional circuits, signals often stray from one circuit to another, resulting in
other calls being heard in the background. This crosstalk is negligible with fiber optics
even when numerous fibers are cabled together.
> Immunity to inductive interference
• Fiber optic cables are immune to interference caused by lightning, nearby electric
motors, relays, and dozens of other electrical noise generators that induce problems
on copper cables unless shielded and filtered.
> High quality transmission
• Fiber routinely provides communications quality orders of magnitude better than
copper or microwave, this as a result of the noise immunity of the fiber transmission
path. (BER: 10-9 – 10-11 for fiber, 10-5 – 10-7 for copper or microwave)
> Low installation and operating costs
• Low loss increases repeater spacing, therefore reducing the cost of capital in the
outside plant. The elimination (or reduction) of repeaters reduces maintenance,
power and operating expenses.