Firstly Call drop is no way related to RF planning in CDMA…
Factor that should be taken into account, in the cellular system design are as follows-
•Co-channel Interference Reduction Factor (CIRF)
•Reverse-Link Power control
•Forward-Link Power control
The designer has to put care in the minimum separation between two co-channel cells, based on the co-channel interference reduction factor.
– The handoff is the necessary overhead in order to switch the call to a new frequency channel in a new cell site without either interrupt the call or alerting the user. Fortunately, based in its intrinsic characteristics, CDMA has a soft handoff problem.
– The reverse-link power control is for reducing near-end to far-end interference. The interference occurs when a mobile unit close to the cell site can mask the received signal at the cell site so that the signal from a far-end mobile unit is unable to be received by the cell site at the same time.
– The forward-link power control is used to reduce the necessary interference outside its own cell boundary.
– Last but not least, The capacity of cellular system can be increased by handling cochannel interference reduction factor properly.