If the reported sub-category No. is 0:
If the BTS3001C works in the E1 transmission mode, set the E1 links from the BSC or the upper-level BTS3001C to a loopback. On the LMT, right-click the EIUB on the BSC Device Panel and choose Query E1/T1 Ports Status on the shortcut menu to query whether the E1 ports connected to the BTS is normal.
If the BTS3001C uses the optical transmission, set the fiber from the BSC or the upper-level BTS3001C to a loopback. On the LMT, right-click the OIUB on the BSC Device Panel and choose Query E1/T1 Ports Status on the shortcut menu to query whether the E1 ports connected to the BTS is normal.
If the reported sub-category No. is 1:
If the BTS3001C works in the E1 transmission mode, set the E1 links from the BSC or the upper-level BTS3001C to a loopback. Check whether the LIU indicator of the lower-level BTS3001C is off.
If the BTS3001C is in works in the optical transmission mode, set the fiber from the BSC or the upper-level BTS3001C to a loopback. Check whether the LIU indicator on the lower-level BTS3001C is off.
Y=> The LIU indicator is off or the alarm is cleared, the transmission link at the peer end of this BTS3001C is normal.
N=> The LIU indicator is on or the alarm is not cleared, the transmission link at the peer end of this BTS3001C is abnormal.