Apple has released iOS 6.1.1 for iPhone 4S devices, presumably fixing the 3G issues that carriers warned their customers about with the iOS 6.1 update. The update, which is specific to the iPhone 4S, comes with a build number of 10B145. It weighs in at a relatively paltry 23MB.
Thanks to @AppleNicholas for the screenshotAbout iOS 6.1.1 Software Update
This update fixes an issue that could impact cellular performance and reliability for iPhone 4S.
Article Link: Apple Releases iOS 6.1.1 for iPhone 4S Devices, Fixes 3G Issues