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OSN3500 SL16 single board has three versions: N1, N2 and N3, the main difference between the three versions is whether they support TCM function and configure AU-3 service.N1SL16 and N2SL16 single boards have been discontinued.The optical interface board is a line board, which can be used on OptiX OSN series devices to realize the reception and transmission of STM-16 optical signals. With this board, the SL16 sends the received optical signals to the crossover side through O/E conversion, while the electrical signals from the crossover side are sent out through E/O conversion.The single board supports functions and features such as receiving and transmitting 1 channel STM-16 optical signals and overhead processing.The single board consists of an optoelectronic conversion module, a multiplexing/demultiplexing module, an SDH overhead processing module, a logic control module, and a power supply module.It supports L-16.2, L-16.2Je, V-16.2Je (plus BA), U-16.2Je (plus SSN1BA2 and SSN1BPA) optical interfaces, of which the L-16.2 optical interface characteristics are in accordance with the recommendations of ITU-T G.957 and ITU-T G.692.L-16.2Je, V-16.2Je (plus BA), U-16.2Je (plus BA), and U-16.2Je (plusBPA) optical interfaces.L-16.2Je, V-16. 2Je (plus BA and PA), and U-16.2Je (plus BA and PA) are Huawei's customized standards.U-16.2Je is compatible with U-16.2.Holding standard wavelength outputs that comply with the ITU-T G.692 recommendations, the optical interfaces of the U-16.2Je can be directly accessed to DWDM (Dense Wavelength Division Multiplexing) equipment.SSN3SL16 supports DWDM color optical interface, the optical interface adopts LC connector. 170km and 640km transmission distance is supported by DWDM optical interface.
Problem Description
Failure phenomenon: Customer feedback on both sides of the signal tuning through the A station found that the error rate before error correction is 6, there is a pre-correction error code overrun alarm BEFFEC_EXC.
Alarm Information Processing Processing Ideas:
1. Insufficient dispersion compensation leads to
2. Nonlinearity or signal-to-noise ratio problems lead to
Processing:
1. Consider dispersion compensation is insufficient to lead to error code problems before error correction. the transmission distance of sites A and B is 303 km, and the cross-segment attenuation is about 60 db. the single board of SF16E is used, and checking the product documentation, the dispersion limited distance of this single board is 120 km, and the customer uses a DCU of 80 km in both directions and a DCU of 40 km in one direction at site A, and the compensated distance is 200 km. the customer uses a DCU of 40 km in one direction, and the compensated distance is 200 km in two directions. The customer uses a two-way 80km DCU and a one-way 40km DCU at station A, and the compensation distance is 200km. According to the dispersion formula: dispersion compensation distance = transmission distance - restricted distance +10~30, the dispersion compensation is sufficient, and dispersion is excluded.
2. Consider the error code before error correction caused by nonlinearity. The sender is BA + RPC01 double-stage amplification, the receiving end of the receiving end of -33dbm or so, according to the 60db or so of the cross-section attenuation, the sender power in 27dbm or so, the incoming optical power is too strong will cause nonlinearities and thus lead to BER, dealing with nonlinearities, a common idea is to add optical attenuation in the sending end of the optical power of the low incoming fiber, but due to unmanned stations in the B site does not have the conditions.
3. After confirming that the incoming fiber power can be reduced by reducing the forward Raman pump power, first try to reduce 0.5db, found that the BER before error correction becomes 8, the BER before error correction cross-limit alarm disappears, and then reduce 0.5db, found that the BER before error correction is 0.
Suggestions and Summary1. When dealing with long-distance transmission BER, if you consider the BER caused by nonlinearity or signal-to-noise ratio, you can solve the problem by adjusting the optical power of Raman pump source, if it is a signal-to-noise ratio problem, you can increase the optical power of the pump source to try, if it is a nonlinear reason to reduce the pump power, reduce the power of the incoming fiber, to avoid nonlinearities caused by too much optical power. The problem of reducing the power of the hair end, the BER disappeared. From the experience of debugging, in the case of BA into the fiber power is large, forward Raman do not open too large, usually ensure that after the equivalent of forward Raman into the fiber power in the +23dB or so.
2. In the adjustment of the pump source optical power should not be adjusted at once too large, in accordance with the 0.5db step gradually adjust the observation.
The technical information in this chapter and the related SDH equipment troubleshooting procedures are provided by Shenzhen Optical Transmission Network Technology Co. Huawei SDH optical transmission equipment, SDH transmission equipment sales phone: 13430988088 Welcome to telephone consultation!
