Apple has released a new version of its iPhone software that resolves the 3G performance issues that have been affecting users of the iPhone 4S who had installed iOS 6.1. The new iOS 6.1.1 is applicable to all iPhone 4S customers:
If you have already installed iOS 6.1
You can download iOS 6.1.1 from Apple immediately, which will deal with the 3G performance issues.
If you are on a previous version of iOS
You can also download iOS6.1.1 from Apple. To do this you must switch your iPhone 4S on and off, which will prompt iOS 6.1.1 to be installed.
The situation will continue to be monitored and we will update you with any further information as we receive it.