RF Unit Maintenance Link Failure

The BBU is connected to RF units by CPRI cables or CPRI optical fibers. The BBU sends handshake messages to RF units. This alarm is reported when the BBU does not receive a response from an RF unit. This alarm may be caused if any the following is faulty: CPRI optical fibers, CPRI cables, optical modules, or board hardware. Services carried on the RF unit are interrupted, and the RF unit cannot be maintained remotely.

Main causes:

? There is a high probability that the AC power supply to the RF units failed or that there is no power supply.

? There is a high probability that an optical module inside the BBU or RF unit is faulty.

? There is a high probability that the CPRI cable or CPRI optical fiber between the BBU and an RF unit or between upper-level and lower-level BBUs is faulty.

from Field O&M Engineers comment, we know,

* Most of the case in this alarm, this problem occurred due to power problem. In this case need to check whether breaker is tripped or MRFU is getting power correctly.

* Problem also can be cleared by changing the CPRI cable, RRU power cable.

* Problem may be solved after changing or resetting GTMU, UBRI card or MRFU to the site.