Technical data
TraverseEdge 2020 Applications and Engineering Guide, Chapter 7: Optical Link Design
Release 5.0.x Turin Networks Page 7-15
dispersion index (ps/nm*km), D
i
, and attenuation index (dB/km), A
i
. In most cases, fiber spans will be
power (or attenuation) limited. It is recommended, however, dispersion be measured/calculated to verify it
does not exceed the limit for a given transceiver.
7.3.1 Maximum Link Distance (L
d
) - Calculated
The maximum link distance (km) for a given Turin Networks’ transceiver may be determined using data
from Table 7-1 through Table 7-13 and using the attenuation index (and dispersion index for OC-48 and
OC-192 links) provided by the fiber manufacturer.
L
d
= P
f
/A
i
; for OC-3 and OC-12 links
L
d
= Minimum[P
f
/A
i
, D
f
/ D
i
]; for OC-48 links
The link distance,
L
d
, is limited either by attenuation (P
f
/A
i
) or dispersion (D
f
/ D
i
), whichever is less.
For convenience, Table 7-16 through Table 7-18 include calculated maximum link distances, Ld,
for each Turin Networks optical PLM over several popular fiber types.
NOTE: These are only typical values; actual maximum span distances achievable on a given fiber
link may be higher or may be lower.
NOTE: The following guidelines and references were utilized to derive the estimated values for the
tables that follow:
• The length of the longest link you can build is the shortest span calculated between the Disper-
sion Limit and the Loss Limit
• The MetroCor Dispersion parameters and Attenuation values were estimated using a graph
from Corning
• SMF-28 and AllWave Dispersion parameters were estimated using Corning's published infor-
mation
• 3dB Margin included for fiber aging and misc losses
• 6dB loss used for end-to-end DWDM passive filter loss
Table 7-16 Calculated Link Distances for Corning SMF-28 ™
Module Name Dispersion
(ps/nm)
Dispersion
Parameter
(ps/nm-km)
Dispersion
Limit (km)
Ptmin
(dBm)
Prmin
(dBm)
Attenuation
(dB/km)
Loss
Limit
(km)
Total Reach
(km)
OC-192 ITU
LR
1
1600 18.0 88.8 +4 -24 0.25 76.00 76 (loss)
OC-192 LR-2 1600 18.0 88.8 -2 -26 0.25 84.00 84 (loss)
OC-192 IR-2 800 18.0 44.4 -1 -14 0.25 40.00 40 (loss)
OC-192 SR-1 500 1.5 333.3 -6 -11 0.5 4.00 4 (loss)
OC-48 ITU 1600 18.0 88.8 +0 -28 0.25 88.0 76 (loss)