UE has reached to its maximum transmission power and causing a radio link failure, what can be the reason?

Question

The radio condition from network side is appropriate but still RLF has happened because of maximum transmission power. Can any one tell me how it is happening in real network?

Answer 1

eNodeb receives CQI report from UE. It may be at eNodeB that UE is not sending proper CQI according to current channel condition and eNodeB assumes that UE has good channel condition and based on that eNodeB using MCS. In such a case, when eNodeB and UE both are not in sync w.r.t to channel condition. It may occur in system.

Please verify air interface log at UE as well as eNodeB. It may help out to you.

Answer 2

UE don't have permission to increase Tx power until eNodeB scheduler request it to raise. There can be many reasons why UE is raising power up to MAX.

1. Check the UE logs that what has gone wrong on UE side and at eNodeB early stage, Check UE behaviors before reaching MAX Transmission power (early transmissions, is there any unhappy message send out from UE or have more data in Buffer).

2. Check if there is anything requested by eNodeB to raise the UE Tx power can cause UE to reach MAX Tx power. If eNodeB had requested the UE and it is the actual case then we have to concentrate on why eNodeB scheduler could not manage proper power within a level.