A terminal device is configured to detect a failure in communicating the position assistance information, such as a failure to decrypt or an integrity protection decoding failure, and in response to detecting the failure in communicating the position assistance information to perform a position assistance information failure procedure. In one example embodiment the position assistance information failure procedure includes transmitting a message indicating the failure to the infrastructure equipment. In another example the position assistance information failure procedure includes adapting one or more communications parameters in order to recover the reception of the position assistance information.