Apple has released a new version for iOS 15 with notable improvements on call performance for the iPhone 13 and iPhone 12.
iOS 15.1.1 has dropped today for iOS users. It’s available as an over the air update for both iPad and iPhone models. Alternatively, the new minor update can be downloaded by going to Settings, then Software Update.

Apple’s release notes say that iOS 15.1.1 improves call drop performance, along with bug fixes. There aren’t any official release notes for the iPad version.
The last iOS 15 update was 15.1, with vaccine cards making an appearance on Apple Wallet and the SharePlay feature being added. iOS 15.1.1 is the first release that fixes the bugs associated with iOS 15.1.
iOS 15.1.1 is now rolling out worldwide via OTA or manual download. It’s recommended that the device is plugged in to a charger while completing the update.