Operator profiles issued by Apple suggest the update could launch on March 9.
This is more than a month after Apple made the iOS 5.1 beta 3 available to developers, and more than three months after the first beta.
Your Daily Mac examined eleven new profiles for various iPhone operators in Japan, France, Greece, Finland and Sweden.
“By updating the profile on the iPhone, it will make sure that the network connection will work correctly after Apple releases iOS 5.1. The iOS updates are normally rolled out at the same time worldwide, so everyone should expect iOS 5.1 to become available next month,” the report states.
iOS 5.1 improvements include the battery life on the iPhone 4S and Siri’s voice dictation. Another important change will be the Facebook integration.