Apple has just released iOS 10.0.3 only for iPhone 7 and iPhone 7 Plus. This small update goes to fix a bug that occurs with the cellular network.
In particular, enabling the Airplane mode and disabling it, many smartphones were unable to tap into the network. On other devices the bug was not the case at all, however upgrading to 10.0.3 is recommended to everyone.
To upgrade you just open Settings> General> Software Update.