Call Drops on Radio Interface in Stable State (Signaling Channel)

Hello Experts.

We have experienced 2G Call drop issue.

Call drop cause is call drops in SDCCH Chanel. CM360:Call Drops on Radio Interface in Stable State (Signaling Channel).

The vendor is Huawei.

U2020 Cell trace done and a lot of error indications were found when analysing drop calls.

Can you suggest optimization actions?