6.2 Additional PWS Requirements Specific to CMAS

22.2683GPPPublic Warning System (PWS) requirementsRelease 18TS

In addition to the General Requirements specified in Clause 4, the following requirements are specified for the deployment of CMAS. These CMAS specific requirements are based on the FCC Report and Orders listed in clause 6.1 and further specified in [4].

Warning Notifications shall support up to 360 characters of GSM 7 bit Default Alphabet [9] for E-UTRAN.

The following classes of Warning Notifications shall be supported: Presidential, Imminent Threat, Public Safety, Child Abduction Emergency (e.g. AMBER) , and State/Local WEA Test.

When a Presidential Warning Notification is received, it shall always be presented to the user whenever Cell Broadcast Service via GSM/UMTS or warning notification delivery via E-UTRAN is enabled on the UE.

If the Presidential Warning Notification is received in English, then it shall be displayed by the UE. If the Presidential Warning Notification is received in a language other than English, then it shall only be displayed by the UE if the User has selected that language.

A CMAS-capable User Interface (UI) shall support the ability for the user to opt-out of only the Imminent Threat, Public Safety and Child Abduction Emergency Warning Notifications. A CMAS-capable User Interface (UI) shall support the ability for the user to opt-in to the State/Local WEA Test notification.

If the User has opted out of a Warning Notification class, then the Warning Notification for that class shall not be displayed by the UE.

If the User has not opted out of a Warning Notification class, then any Warning Notifications for that class received in English shall be displayed by the UE. This also applies to Warning Notifications received in any additional languages that may be selected by the User.

Warning Notifications may contain URLs and/or phone numbers.

A CMAS-capable User Interface (UI) shall support the ability (e.g., a “click” touch input) for the user to navigate to the URL or initiate a voice call to the phone number which may be included in the Warning Notification [8].

The PLMN broadcasting CMAS Warning Notifications shall also broadcast corresponding CMAS Warning Notification Area(s) when the CMAS Warning Notification is required to adhere to the maximum 0,1 of a mile CMAS Warning Notification Area(s) overshooting as specified in [10]. This requirement applies only to LTE and NR accesses.

A CMAS-capable UE shall utilize UE-Based Location Calculation (see 3GPP TS 22.071 [11]) to determine whether it is located within the corresponding CMAS Warning Notification Area(s) in order to minimize overloading network LCS resources.

Subject to opt-out and opt-in settings described above, a CMAS-capable UE shall present the CMAS Warning Notification sent if there is a corresponding CMAS Warning Notification Area(s) and if the CMAS-capable UE is able to determine that its location is within the corresponding CMAS Warning Notification Area(s). Otherwise, if a CMAS-capable UE is unable to or fails to determine its location, the CMAS-capable UE shall present the Warning Notification to the user.

A CMAS-capable UE shall store presented Warning Notifications for at least 24 hours unless explicitly deleted by the user.