Apple is rolling out iOS 15.1.1 update this week, which is classed as a bug fix release that could make all the difference to the quality of your calls.
XDA Developers reports said:
15.1.1 is aimed at iPhone 12 and iPhone 13 owners as it improves the call drop performance of both models. We haven’t heard many complaints about call drops, but it’s clearly a big enough problem to make Apple take notice and issue a fix. Also, iOS 15.2 is going to be a much more interesting update, offering a number of tweaks to improve user privacy and security. It’s expected to arrive within the next two months, but hopefully we’ll get it before the end of the year.
How To Install Apple iOS 15.1.1 Update
Installing the update requires navigating to the Settings app on your iPhone, then tap General -> Software Update and wait for your phone to check and refresh the screen. The iOS 15.1.1 should appear if Apple had made it available in your location and you can tap to download and install it.