Is it mandatory to initiate an RACH in Scell activation during InTra eNB CA?

Question

What is the behavior of UE if Scell Rach fails?

Answer 1

I think RACH procedure only needed if cells are non-collocated i.e HetNet scenario using Inter-Band carrier
aggregations where antennas are distributed and connected via fiber links, the use of multiple timing advance is
necessary. Immediately after the SCell activation, the NodeB PCell will request a RACH on the SCell.