Call drop caused by F-TCH power limitation

Typical case:
As MS moves, MS Rx power and pilot Ec/Io is decreasing, but they are still enough to maintain the link, like: Rx power>-100dBm, Ec/Io >-15dB; As MS moves, its reverse Tx power is increasing, but it is still enough to maintain the
link; As MS moves, Tx_Adj can maintain the normal state; When MS is far away from BTS, F-FER will increase very fast, until call drop; MS will re-initialize after call drop and stay in the previous pilot.

Analyzing:
Traffic channel gain can be set in background, if the setup value is too low, system can not assign enough power resource to traffic channel. In the above case, according to DT test it can be observed that Ec/Io and Rx power are all higher than threshold (Ec/Io>-15dB, Rx>-100dBm); But when MS is far away from BTS, F-FER increases very fast until call drop. The reason may be forward traffic channel gain is too low and the power is not enough. After call drop, MS will re initialize and stay in previous pilot. The confirm method is use the instrument which can measure code domain power (like
Viper) to test.

Optimization method:
Check background parameters setup and adjust forward traffic channel maximum gain.

Call drop caused by handoff failure
Handoff failure is one of main reasons for call drop, when MS moves from one cell to another cell, handoff will happen; if handoff is failed, signal of the current cell will become worse and worse, F-FER and R-FER will be very high, then call drop will happen when MS fading timer expires.