530
13 Fiber Optic Communication Networks
≈ 5.5 cm
≈ 1.4 cm
Transmit and receive
optical connections
Fig. 13.16 A standard SFP transceiver package with transmit and receive optical connections
13.4.1 Links Operating at 10 Gb/s
Owing to product improvement efforts, several multimode fibers with different bandwidth grades exist for short-distance 10-Gb/s and beyond use. To identify these
different fiber categories, the ISO/IEC 11801 Structured Cabling Standard gives four
classifications of multimode fiber in terms of bandwidth. As Table 13.6 shows, these
fibers are referred to as grades OM1 through OM5. Note that the values of the bandwidth depend on the measurement standard used, and the maximum transmission
distances may vary depending on the exact fiber design from different manufacturers.
To summarize this table, note the following characteristics:
Table 13.6 Multimode fiber classifications and their use with 1- and 10-Gb/s Ethernet
Fiber class
and size
BW @
850 nm
(MHz-km)
BW @
1300 nm
(MHz-km)
Max distance
for 1 Gb/s @
850 nm (m)
Max distance
for 1 Gb/s @
1300 nm (m)
Max distance
for 10 Gb/s @
850 nm (m)
OM1
62.5/125
200
500
300
550
33
OM2 50/125 500
800
750
200
82
OM3 50/125 2000
500
950
600
300
OM4 50/125 4700
500
1040
600
550