13.3 Basic SONET/SDH Concepts
523
Table 13.3 Wavelength ranges and attenuation for transmission distances up to 80 km
Distance (km) Wavelength range
at 1310-nm (nm)
Wavelength range
at 1550-nm (nm)
Attenuation at
1310 nm (dB/km)
Attenuation at
1550 nm (dB/km)
≤15
1260–1360
1430–1580
3.5
Not specified
≤40
1260–1360
1430–1580
0.8
0.5
≤80
1280–1335
1480–1580
0.5
0.3
The receiver sensitivities designated in G.957 are the worst-case, end-of-life
values. They are defined as the minimum-acceptable, average, received power needed
to achieve a 10
−10 BER. The values take into account extinction ratio, pulse rise
and fall times, optical return loss at the source, receiver connector degradations,
and measurement tolerances. The receiver sensitivity does not include power penalties associated with dispersion, jitter, or reflections from the optical path; these are
included in the maximum optical path penalty. Table 13.4 lists the receiver sensitivities for various link configurations up through long-haul distances (80 km). Note
that the specifications and recommendations are updated periodically, so the reader
should refer to the latest version of the documents for specific details.
Longer transmission distances are possible using higher-power lasers. To comply
with eye-safety standards, an upper limit is imposed on fiber-coupled powers. If the
maximum total output power (including ASE) is set at the Class-3A laser limit of
Table 13.4 Source output, attenuation, and receiver sensitivity ranges for various rates and distances
up to 80 km (see ITU-T G.957)
Parameter
Intraoffice Short-haul (1) Short-haul (2) Long-haul (1) Long-haul (3)
Wavelength (nm) 1310
1310
1550
1310
1550
Fiber
SM
SM
SM
SM
Distance (km)
≤2
15
15
40
80
Designation
I-1
S-1.1
S-1.2
L-1.1
L-1.3
Source range (dBm)
155 Mb/s
−15 to −8 −15 to −8
−15 to −8
0 to 5
0 to 5
622 Mb/s
−15 to −8 −15 to −8
−15 to −8
−3 to +2
−3 to +2
2.5 Gb/s
−10 to −3 −5 to 0
−5 to 0
−2 to +3
−2 to +3
Attenuation (dB)
155 Mb/s
0 to 7
0 to 12
0 to 12
10 to 28
10 to 28
622 Mb/s
0 to 7
0 to 12
0 to 12
10 to 24
10 to 24
2.5 Gb/s
0 to 7
0 to 12
0 to 12
10 to 24
10 to 24
Receiver sensitivity (dBm)
155 Mb/s
−23
−28
−28
−34
−34
622 Mb/s
−23
−28
−28
−28
−28
2.5 Gb/s
−18
−18
−18
−27
−27
523
Table 13.3 Wavelength ranges and attenuation for transmission distances up to 80 km
Distance (km) Wavelength range
at 1310-nm (nm)
Wavelength range
at 1550-nm (nm)
Attenuation at
1310 nm (dB/km)
Attenuation at
1550 nm (dB/km)
≤15
1260–1360
1430–1580
3.5
Not specified
≤40
1260–1360
1430–1580
0.8
0.5
≤80
1280–1335
1480–1580
0.5
0.3
The receiver sensitivities designated in G.957 are the worst-case, end-of-life
values. They are defined as the minimum-acceptable, average, received power needed
to achieve a 10
−10 BER. The values take into account extinction ratio, pulse rise
and fall times, optical return loss at the source, receiver connector degradations,
and measurement tolerances. The receiver sensitivity does not include power penalties associated with dispersion, jitter, or reflections from the optical path; these are
included in the maximum optical path penalty. Table 13.4 lists the receiver sensitivities for various link configurations up through long-haul distances (80 km). Note
that the specifications and recommendations are updated periodically, so the reader
should refer to the latest version of the documents for specific details.
Longer transmission distances are possible using higher-power lasers. To comply
with eye-safety standards, an upper limit is imposed on fiber-coupled powers. If the
maximum total output power (including ASE) is set at the Class-3A laser limit of
Table 13.4 Source output, attenuation, and receiver sensitivity ranges for various rates and distances
up to 80 km (see ITU-T G.957)
Parameter
Intraoffice Short-haul (1) Short-haul (2) Long-haul (1) Long-haul (3)
Wavelength (nm) 1310
1310
1550
1310
1550
Fiber
SM
SM
SM
SM
Distance (km)
≤2
15
15
40
80
Designation
I-1
S-1.1
S-1.2
L-1.1
L-1.3
Source range (dBm)
155 Mb/s
−15 to −8 −15 to −8
−15 to −8
0 to 5
0 to 5
622 Mb/s
−15 to −8 −15 to −8
−15 to −8
−3 to +2
−3 to +2
2.5 Gb/s
−10 to −3 −5 to 0
−5 to 0
−2 to +3
−2 to +3
Attenuation (dB)
155 Mb/s
0 to 7
0 to 12
0 to 12
10 to 28
10 to 28
622 Mb/s
0 to 7
0 to 12
0 to 12
10 to 24
10 to 24
2.5 Gb/s
0 to 7
0 to 12
0 to 12
10 to 24
10 to 24
Receiver sensitivity (dBm)
155 Mb/s
−23
−28
−28
−34
−34
622 Mb/s
−23
−28
−28
−28
−28
2.5 Gb/s
−18
−18
−18
−27
−27