3Com DUA3700-0BAA04 manual Table E-1 Standard Multi-mode Fiber Specification

ATM Cabling E-5

Table E-1Standard Multi-mode Fiber Specification

Specification	Description
Core	62.5 µm diameter
Cladding	125	µm diameter nominal
	122	µm minimum
	128	µm maximum
Numerical aperture	0.275
Maximum attenuation	11 dB* (1dB allowed for reflection and
	dispersion penalties.)
Modal bandwidth	500	MHz. km
Maximum distance between nodes	2 km
Output power (from transmitter)	19 dB minimum
	14 dB maximum
Receive power	30 dB minimum sensitivity
	14 dB maximum sensitivity

*Maximum attenuation includes cable attenuation and the loss induced by other components such as connectors, splices, and the mating of unlike fiber types. Although some 2 km cable plants have a total attenuation of less than 11.0 dB, the 2 km interstation distance must be maintained to comply with modal bandwidth requirements.

Table E-2Alternate Multi-mode Fiber Types

Core (µ m)	Cladding (µ m)	Numerical Aperture
50	125	0.20
50	125	0.22
85	125	0.28
100	140	0.29

Calculating Insertion If unlike fibers are mated in the cable plant, calculate insertion losses to Losses for Unlike be certain that the cable plant does not exceed the maximum attenuation

Fibers value listed in Table E-1. To calculate the insertion loss, consider the types of fiber in the cable plant and the connectors or splices used to join them. Compare the result to the maximum attenuation value listed in Table E-1. If the result is greater than the value in the table, use only like fibers in the cable plant.