Apple today released iOS 15.1.1 for the iPhone 12 ans iPhone 13 series. This minor point release from the company improves the call drop performance on these iPhones.
iOS 15.1 and iPadOS 15.1 were major point releases of the OS bringing SharePlay, ProRes video recording, and more. Apple has also already seeded the three beta builds of iOS 15.2, with some notable changes. This iOS 15.1.1 release from Apple is a surprising one since it is only for the iPhone 12 and 13, and it only fixes one issue: that of call drops.
You can install the iOS 15.1.1 update on your iPhone 12/13 by navigating to Settings -> General -> Software Update.
If you find any other changes in iOS 15.1.1, drop a comment and let us know about it.