Single-port, high-speed OC-192 OLIUs (LNW56 and LNW58)

Optical specification

This section briefly details the optical specifications for the OC-192 LNW56 and LNW58 circuit packs.

LNW56

The LNW56 circuit pack is a high-speed, intermediate reach OLIU that meets or exceeds SONET OC-192 1550 IR-2 specifications. The LNW56 circuit pack bridges span lengths up to 40 km. The LNW56 transmits in the general 1550 nm range.

LNW58 (optical interface for intra-office applications)

The LNW58 is a high-speed, very short reach (VSR) OC-192 OLIU that meets or exceeds ITU G.693 VSR600-2R1 specifications. The LNW56 circuit pack bridges span lengths up to 600 meters. The LNW58 transmits in the general 1310 nm range.

System specifications

The table below lists the OC-192 OLIU system specifications.

Important!

At high optical launch powers, SBS can cause an acoustic back-scattering phenomenon in fibers. The dither tone effectively broadens the spectrum of the narrow optical pulse, thus raising the threshold power where SBS becomes an issue.

For fibers carrying multiple wavelengths in DWDM systems, it should be noted that the individual channel (individual wavelength) power determines the SBS threshold, not the total composite power of all the channels.

Table 10-22: LNW56 and LNW58 optical system specifications

System information	LNW56	LNW58
Optical Line Rate	9953.28 Mb/s
Optical Line Coding	Scrambled NRZ
Optical Wavelength	1550 nm	1310 nm
Performance	GR-253-CORE OC-192 Intermediate Reach, IR-2	ITU-T G.693 Very Short Reach, VSR600-2R1
Temperature Range	Central Office/Commercial (0°C to 70°C)

Transmitter specifications

The table below lists the LNW56 and LNW58 OLIU transmitter information.

Table 10-23: LNW56 and LNW58 optical transmitter information

Transmitter information	LNW56	LNW58
Optical Device Temperature Controller	None
IEC 60825 Laser Classification	Class 1
FDA Laser Classification	Class I
Optical Source	1550 nm, EML Laser Structure	1310 nm, FP or DFB Laser Structure
Faceplate Optical Connector	LC connector

Receiver specifications

The table below lists the LNW56 and LNW58 OLIU receiver information.

Table 10-24: LNW56 and LNW58 optical receiver information

Receiver information	LNW56	LNW58
Optical Detector	PIN Diode	PIN Diode
Faceplate Optical Connector	LC connector

Link budgets

The table below lists the LNW56 and LNW58 OLIU link budgets.

Table 10-25: LNW56 and LNW58 specifications and link budgets

Parameter¹	LNW56	LNW58
Minimum Wavelength	1530 nm	1260 nm
Maximum Wavelength	1565 nm	1360 nm
Maximum Spectral Width (Δλ₂₀)	1.0 nm	NA
Maximum RMS Spectral Width (σ)	NA	3.0 nm
Minimum Side Mode Suppression Ratio	30 dB	NA
Maximum Transmitter Power	2.0 dBm	−1.0 dBm
Minimum Transmitter Power	−1.0 dBm	−6.0 dBm
Maximum Received Power	−1.0 dBm	−1.0 dBm
Minimum Received Power (1x10⁻¹² BER)	−14.0 dBm	−11.0 dBm
Minimum System Gain²	13.0 dB	5.0 dB
Dispersion	800 ps/nm	NA
Optical Path Penalty³	2.0 dB	1.0 dB
Minimum Optical Return Loss⁴	24.0 dB	14.0 dB
Maximum Receiver Reflectance⁴	−27.0 dB	−14.0 dB
Optical Signal to Noise Ratio (OSNR); 1x10⁻¹² BER, −10 to −20 dBm, +1600 ps/nm, 0.1 nm RBW	NA	NA
Minimum Loss Budget⁵	3.0 dB	0.0 dB
Maximum Loss Budget⁶	11.0 dB	4.0 dB
Approximate Span Length⁷	40 km	600 meters

Notes:

All terminology is consistent with GR-253-CORE, Issue 3 and ITU G.693. All values are worst-case end of life. Optical specifications meet or exceed equivalent GR-253-CORE requirements.
The system gain includes connector loss at the transmitter and receiver points S and R in GR-253-CORE, Issue 3.
Optical path penalty includes effects of dispersion, reflection, and jitter that occur on the optical path. The optical path penalty for 1310 nm is a maximum of 1.0 dB. The optical path penalty for 1550 nm is a maximum of 2.0 dB.
Refer to GR-253-CORE for more information about these parameters.
For all packs and PTMs where the Minimum Loss Budget (MLB) is 0, no attenuator is required for loopbacks. For all packs and PTMs where the MLB is greater than 0, an attenuator is required. The value of the LBO must be equal to or greater than the MLB.
The stated maximum loss budget equals the minimum system gain, minus the optical path penalty. Maximum loss budget is available for both station and transmission cable and splices.
The Approximate Span Length values are calculated per an attenuation assumption. As a general rule, for attenuation-limited systems, an attenuation of 0.27 dB/km is used for 1550 nm optics. This estimate includes typical cable loss (0.22 dB/km) and up to 11 splice losses (0.2 dB per splice). For 1550 nm OC-192 systems, dispersion can also be a limiting factor. Approximate Span Lengths can be calculated more precisely based on particular fiber and splice characteristics and local engineering rules. Note that the 1310 nm VSR OC-192 LNW58 is recommended for spans of up to 600 meters only.

Alarm thresholding

The following parameters are monitored on the OC-192 interface:

LOS
LOF
AIS-L
RFI-L (FERF)
Signal Degrade (BER)
Signal Fail (BER)

Performance monitoring

SONET line and path performance monitoring complies with the standards outlined in GR-253-CORE. For detailed PM parameter thresholds on the OC-192 interface, see Performance monitoring.