Alcatel-Lucent 1675 LambdaUnite Installation And System Turn-Up Manual page 443

Network establishment and testing
...................................................................................................................................................................................................................................
Required equipment
Prior to performing this task, the following equipment must be available:
1. Optical power meter
– Range: –35 ... +20 dBm
– Wavelength: 1310 nm/1550 nm
2. ESD wrist strap.
Prerequisites
Prior to performing this task, all used optical ports and connectors must be clean. A
cleaning procedure is given in appendix A, section
(p. A-24).
Background information
LC attenuator
The LC attenuator which will be determined in the procedure described below should be
placed on the I PUT port because this is the furthest physical point on the fiber line from
the OUTPUT port and takes all connector losses into account. If SFPs are used this
proposed solution is important in particular because this causes less level fluctuations if
the fibers are moved.
Fiber plugging / Signal Degrade (SD) clearing
The following can be observed if the fiber is plugged manually:
Firstly, the LOS is cleared. As soon as the bit error rate is low enough (better than ≈ 10
the device frames to the signal. As soon as the framing happens, the SD mechanism starts.
The manual plugging is "slow" compared to the reaction time of the SD detection with
fast termination. It takes hundreds (maybe thousands) of frames until the signal is finally
error free. SD will be detected nearly immediately (10 ms).
While the plugging continues the signal gets better. Depending on the speed of plugging,
the SD may get re-detected several times and the interval is restarted.
Finally, SD will not be re-detected anymore (not enough errored frames) and the interval
will expire normally. However, even if the SD threshold is not reached anymore, most
likely the number of errored frames is (due to the hysteresis; see section "SD detection
mechanism") still too high to clear the SD. Therefore a second interval of the detection
must expire before the SD gets finally cleared.
SD detection mechanism
The SD detection is interval-based. As soon as an SD condition is detected (or confirmed)
or deleted (or confirmed as being non- existent) the detection interval restarts.
...................................................................................................................................................................................................................................
365-374-198R10.5.4
Issue 1 July 2009
Alcatel-Lucent – Internal
Proprietary – Use pursuant to Company instruction
Network establishment
Procedure 10-1: Connecting the fiber cables
Procedure A-13: "Fiber cleaning"
–4
)
10-5