Optical Wavelength Conversion Unit. STM-64 Transmitting Optical Wavelength Conversion Unit with FEC Function, страница 2

n  Nominal central frequency: 192.1 ~ 195.2 THz, completely complying with ITU-T G. 692 recommendation. As shown in Figure 3-2, with the laser optical wavelength stabilization technology, the maximum frequency offset is not over 10 GHz (within the service life).

Figure 3-2 Laser optical wavelength stabilization technology

n  Minimum extinction ratio: > 10 dB.

n  Eye pattern: in compliance with ITU-T G. 691 recommendation.

n  Optical channel cost: < 2 dB.

n  Minimum receiving sensitivity of the optical receiver: -14 dBm (PIN receiving module) (under the condition of bit error rate BER = 1.0 E-12).

n  Overload optical power of the optical receiver: 0 dBm (PIN receiving module).

n  Error correcting encoding adopts RS (255, 239, 17) standard code to extend the transmission distance without the repeaters.

n  Provide the monitoring on regeneration section B1 byte (B1 error code report, B1 over threshold, B1 deterioration), on multiplex section B2 byte (B2 error code report, B2 over threshold, B2 deterioration) to locate the line fault, and on regeneration section trace J0 byte.

n  TWF provides the following monitoring functions: laser bias current monitoring, laser cooling current monitoring, laser transmitting optical power monitoring and incident optical power monitoring.

n  TWF has automatic laser shutdown (ALS) function.

3. Application

n  TWF optical input port receives STM-64 signal in compliance with ITU-T G.691 recommendation, and optical output port sends STM-64 optical signal in compliance with ITU-T G. 692 recommendation to optical multiplexer unit for multiplexing.

n  TWF can be inserted in 1 ~ 13 board position of OptiX BWS 320G subrack.

n  The optical connector on TWF board handle bar is of SC type.

4. Common alarm performance

TWF board mainly consists of optical receiving module and optical transmitting module, so its alarms mainly reflect the working status of these two modules. Alarms of TWF board are shown in Table 3-1.

Table 3-1 TWF board alarm table