363-206-285
Technical Specifications
Issue 3 June 2001
10-19
Long Reach OC-3 Interface (22G-U/22G2-U/
22G3-U/22G4-U OLIU) 10
■ Optical Specification
The multilongitudinal mode (MLM
*
) laser transmitter supplies an NRZ-
coded signal. For direct optical loopbacks, at least 7.0 dB (use 10 dB
attenuator, see Table 10-21) of attenuation is needed for the 22G-U. No
attenuation is needed for the 22G2-U, 22G3-U, or 22G4-U.
The 22G-U/22G2-U OLIU long reach OC-3 interface supports span lengths
up to 51 km, assuming 0.45 dB/km single-mode fiber and the span
engineering rules outlined in Table 10-8. Transmit and receive powers are
referenced to Points S and R as shown in Figure 10-2. Table 10-7,
Table 10-8, and Table 10-9 provide detailed specifications and link budget
information for the 22G-U/22G2-U OLIU.
The 22G3-U/22G4-U OLIU is a SONET compliant long reach OC-3
interface supporting span lengths up to 55 km, assuming 0.45 dB/km
single-mode fiber and the span engineering rules outlined in Table 10-8.
Transmit and receive powers are referenced to Points S and R as shown in
Figure 10-2. Table 10-7, Table 10-8, and Table 10-9 provide detailed
specifications and link budget information for the
22G3-U/22G4-U OLIU.
■ Alarm Thresholding
The following parameters are monitored at the OC-3 interface.
— Loss of signal (LOS)
— Loss of frame (LOF)
— Loss of pointer (LOP)
—LineAIS
— B2 thresholding signal fail
— B2 thresholding signal degrade. (B2 signal degrade thresholds are
user settable in the range from 10
-5
to 10
-9
BER.)
■ Performance Monitoring (see Table 10-23)
— Section SEFS
— Line parameter B2.
— STS pointer justifications (Release 11.0 and later).
* A higher quality SLM laser may be used instead of an MLM laser.
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