A2 Event Threshold setting on eNB


In cases where there is a coverage overlap between sectors on the same tower or overlap between sectors of different towers A2 measure in the eNB settings has been discovered to be a key contributor towards maintaining a stable connection between the eNB and CPE. A2 event is triggered when the serving cell RSRP goes below the set threshold value in the eNB settings. Let’s say the threshold value is set to 65, the way it works is A2 = 65-140 = -75dBm. Therefore as soon as the RSRP reaches below -75dBm the A2 event is triggered and the CPE starts looking for a signal better than -75dBm thus, throttling its connection with current eNB which can cause CPE drop offs and jump between eNBs( except for when they are PCI locked). This case is helpful for mobile devices that are moving around and need handover. Since handover is not required for fixed users in such cases A2 setting can be lowered down to zero, so that the A2 threshold = 0-140= -140 dBm . This will prevent the CPE from searching for other potential eNBs serving a signal better than -140 dBm. Please note this has proved beneficial and helpful in increasing the UL and DL MCS mostly in cases of overlapping cell coverage.

Please note for the setting to take effect the eNB has to be rebooted after changing the setting.

You can find the setting under eNB GUI>>LTE settings>>mobility parameter>>A2 event threshold: