COMe-cWL6 – User Guide Rev. 1.4
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5.1.
MTBF
The following MTBF (Mean Time Before Failure) values were calculated using a combination of manufacturer’s test
data, if the data was available, and the Telcordia (Bellcore) issue 2 calculation for the remaining parts.
The Telcordia calculation used is “Method 1 Case 3” in a ground benign, controlled environment (GB,GC). This
particular method takes into account varying temperature and stress data and the system is assumed to have not
been burned in.
The figures below shows MTBF de-rating for the different temperature range in an office or telecommunications
environment. Other environmental stresses (such as extreme altitude, vibration, salt-water exposure) lower MTBF
values.
Figure 6: System MTBF (hours) = 565206 h @ 40°C (Reliability report article number 36028-1610-17-7)