is it a “satellite abis” BTS ? if yes, then … well, i don’t know, that can create some delay on the sdcch signalling. what is the average time of sdcch dialogs ?
– try removing the adaptative configuration of logical channels and set 2 full timeslots for SDCCH (or 3, or 4, test different configurations out)
– try changing the frequencies
– try reducing the timing advance filter (instead of 64 (32km), set it to 15 (= 7.5km) for a few hours .
For info, the RXLEV MIN is different from the RXLEV ACCESS MIN. Beware. First one : for HO. Second one : for Call Setup. Be sure you set the latter to