Erab Drops 1b5ur

3) eRAB Drops Whole network faults Performance counters are abnormal Alarms reported Single eNodeB faults Performance counters are abnormal for certain cell Alarms reported Possible Causes Data transmission is abnormal Network planning is improper EPC works abnormally (for whole network fault) Insufficient resources (for single cell) Weak coverage (for single cell) Interference (for single cell) SOLVE For Whole Network: Check cutover, replacement, upgrade, or patch installation Check eNodeB parameters changes for a big amount of cells Check traffic volume RF faults Caused by faults such as the number of RLC retransmissions reaching the maximum, UE uplink out-of-synchronization, or signalling procedure failures Weak coverage UL interference UE exceptions TXON faults Caused by TXON exceptions between eNodeB and MME Check TXON related alarms Congestion Any resource reaches the limit Capacity expansion Recommended action: Enable MBL Possible other actions: make easier outgoing HO and harder incoming HO; reduce power; increase minimum required level; reduce bit rate; reduce resources assignment HO Failures Check parameter settings for destination cells with HO failures Check parameter settings for origin cell if all destination cells are fa iling See HO sections MME Faults It has to be identified on the EPC side