Thanks alot to each of you for your support.
I am happy to inform you that i fixed the issue about poor SDCCH Acc by changing the Multiplex Mode from 2:1 to 1:1 and add 1 more E1 because the issue was LapDLink congestion during Busy Hour.
Now my KPIs are looking very good
CSR from 40% to 99% for the concerned cells.
Again, thanks alot to all of you.