Determining Fiber Cable Lengths Using Alternate Fiber Diameters; Multimode Fiber Specifications; Alternate Fiber Diameter Distances; Fiber Optical Budget - 3Com CoreBuilder 5000 User Manual

2-10 D E
ESIGNING AND XPANDING THE
Determining Fiber
Cable Lengths Using
Alternate Fiber
Diameters
N
ETWORK
The fiber must comply with the specifications listed in
with ANSI/EIA/TIA - 492AAAA. You can use cables of this type up to
2 km long.
Table 2-9

Multimode Fiber Specifications

Maximum
Wavelength Attenuation
850 3.75 dB/km
Table 2-10 contains distance estimates that may not have been tested.
Use the alternate fiber diameter distances listed to help you determine
the fiber cable length associated with the use of alternate fibers. The
result is based on 62.5/125 (the defacto cable that you use). By
specification, the maximum distance for any fiber length is 2 kilometers.
Table 2-10

Alternate Fiber Diameter Distances

Alternate
Diameter Fiber Average Transmit
Size Power (dBm)
50/125 -16.4 to -22.4
62.5/125 -13 to -19
85/125 -10.7 to 16.7
100/140 - 8.8 to -14.8
* If you use 85/125 or 100/140 as your alternate fiber diameter distance, you can overdrive
the receiver.
Table 2-11

Fiber Optical Budget

50 Micron Core
920 meters
Maximum into Transmission Capacity
(MHz-km)
160
Receiver Power
Range (dBm)
-12 to -28
-12 to -28
-12 to -28
-12 to -28*
85 Micron Core
3.44 km
Table 2-9 and
Minimum Link
Loss Required
(db)
0
0
*
1.3
4
100 Micron Core
5.3 km