According to Apple’s release notes, iOS 15.1.1 improves call drop performance on iPhone 12 and 13 models, so users who have been experiencing dropped calls should see improvements after installing the update. It appears to only be available for devices in the ?iPhone 12? and iPhone 13 families, including Pro models, so users with other devices won’t see the update.

Here are the direct download links:

• iOS 15.1.1 (Build 19B81) for:
  • iPhone13,1 (iPhone13,1) — Download
  • iPhone13,2 (iPhone13,2) — Download
  • iPhone13,3 (iPhone13,3) — Download
  • iPhone13,4 (iPhone13,4) — Download
  • iPhone14,2 (iPhone14,2) — Download
  • iPhone14,3 (iPhone14,3) — Download
  • iPhone14,4 (iPhone14,4) — Download
  • iPhone14,5 (iPhone14,5) — Download