Comparing Fiber To Specifications - 3Com CoreBuilder 2500 Getting Started Manual

D-6 A D: FDDI S
PPENDIX
Comparing Fiber to Specifications
Compare the specifications of the fiber you are
using to those in Table
meet the specifications, use a different fiber or
contact 3Com Technical Support.
The single mode PMD specification (SMF-PMD)
defines two optical power categories: Category 1
and Category 2. These categories refer to the
optical power that must be launched into the fiber
by the transmitter or detected by the receiver. 3Com
supports only Category 1 single mode fiber.
The specifications for the standard single mode fiber
are listed in Table D-6. Refer to the Category 1
specifications in this table for fiber connecting
3Com equipment. For fiber used with Category 2
equipment from another vendor, refer to the
Category 2 specifications.
The cable plant for a Category 2 implementation
must have a minimum loss of 15 dB. In a Category
2 implementation, minimum cable plant losses are
required to avoid saturating (blinding) the receiver.
TANDARDS
D-6. If the fiber does not
Table D-6 Single Mode Fiber Specifications
Category Specifications
Both Categories Core
Cladding
Category 1 Output power
(from transmitter)
Receive power
Maximum
distance* between
nodes
Maximum
attenuation †
Category 2 Output power
(from transmitter)
Receive power
Maximum
distance * between
nodes
Maximum
attenuation †
* Maximum distances assume cable with one splice every
2.2 km with 0.3 dB loss each, and with no patch panels or
mechanical splices.
† Maximum attenuation includes cable attenuation and the
loss induced by other components such as connectors,
splices, and the mating of unlike fiber types.
Description
8 to 10 mm
125 mm (± 2 mm)
–20 dB minimum
–14 dB maximum
–31 dB minimum
–14 dB maximum
14.4 km
10 dB (1 dB allowed
for reflections and
dispersion penalties)
–4 dB minimum
0 dB maximum
–37 dB minimum
–15 dB maximum
58.6 km
32 dB (1 dB allowed
for reflections and
dispersion penalties)