Section: 5.5.1 Visibility
Content: Although in general the security features should be transparent to the user, for certain events and according to the user's concern, greater user visibility of the operation of security features should be provided. This yields to a number of features that inform the user of security-related events, such as: - indication of access network encryption: the property that the user is informed whether the confidentiality of user data is protected on the radio access link, in particular when non-ciphered calls are set-up; - indication of the level of security: the property that the user is informed on the level of security that is provided by the visited network, in particular when a user is handed over or roams into a network with lower security level (3G à 2G). The ciphering indicator feature is specified in 3GPP TS 22.101[ Service aspects; Service principles ]  [ 21].