This formula also applies to Single Mode systems
For example, if two couplers are used in the cable, c = 2, the maximum length
would be
L
optical
= 1 km
The second limiting factor for cable length is fiber cable bandwidth.
Bandwidth limit is caused by light pulse dispersion in the optical fiber; this only
affects Multi Mode fiber systems.
This limit is the product of the GHS system's maximum signaling speed and the
defined fiber cable bandwidth.
GHS signaling speed over optical fiber : 1000 MHz
OM class defined bandwidth
: BW
Maximum fiber cable length
:
L
BW
(km)
L
BW
MHz
BW
=
(
km
)
1000
For example, if an OM2
-
type cable is used, the maximum length will be
L
BW
=
0.5 km
The maximum optical fiber length that can be used in a setup is the
shortest outcome of
L
optical
or L
BW
If the two examples above are followed, the optical fiber length must be limited
to
L
BW
= 0.5 km
GEN3i
946
I3763-3.1 en HBM: public
