Hi,
at which stage u find sd drop means its at rf interface…or e n thing else…
if it is so thn plaese check frequency plan ….bcz one reson for sd drop is interference.
as such u hv written RLT para..for TCH drop…dis type of solution for sd is u can reduce RXP(rx_access_min) to -100dbm so mobile will not latch on lower level hence no sd drop …u can improve some what…but check interferance if high sd drop is occuring.