4 General PWS Requirements

22.2683GPPPublic Warning System (PWS) requirementsRelease 18TS

4.1 Background

Recently there has been an interest to ensure that the public has the capability to receive timely and accurate alerts, warnings and critical information regarding disasters and other emergencies irrespective of what communications technologies they use. As has been learned from disasters such as earthquakes, tsunamis, hurricanes and wild fires; such a capability is essential to enable the public to take appropriate action to protect their families and themselves from serious injury, or loss of life or property.

This interest to enhance the reliability, resiliency, and security of Warning Notifications to the public by providing a mechanism to distribute Warning Notifications over 3GPP systems is the impetus for this Public Warning System Technical Specification.

4.2 High level general requirements for Warning Notification delivery

The following list gives the high level general requirements for Warning Notification delivery:

– PWS shall be able to broadcast Warning Notifications to multiple users simultaneously with no acknowledgement required.

– PWS shall be able to support concurrent broadcast of multiple Warning Notifications.

– Warning Notifications shall be broadcast to a Notification Area which is based on the geographical information as specified by the Warning Notification Provider.

– PWS capable UEs (PWS-UE) in idle mode shall be capable of receiving broadcasted Warning Notifications.

Note: A bandwidth reduced low complexity UE or a UE supporting eDRX may not support all requirements for PWS, including ETWS, CMAS, EU-Alert and KPAS

– PWS shall only be required to broadcast Warning Notifications in languages as prescribed by regulatory requirements.

– Warning Notifications are processed by PWS on a first in, first out basis, subject to regulatory requirements.

– Reception and presentation of Warning Notifications to the user shall not pre-empt an active voice or data session.

– Warning Notifications shall be limited to those emergencies where life or property is at imminent risk, and some responsive action should be taken.

NOTE: This requirement does not prohibit the use of the operator’s network (i.e. broadcast technology) implemented for Warning Notifications to be used for commercial services.

4.3 Warning Notification Content

PWS shall not modify or translate the Warning Notification content specified by the Warning Notification Provider.

It is expected that Warning Notifications would likely include the following five elements:

– Event Description

– Area Affected

– Recommended Action

– Expiration Time (with time zone)

– Sending Agency

Additional elements may be present, based on regulatory requirements.

There is a concern that URLs or telephone numbers in a Warning Notification could exacerbate wireless network congestion at a time when network traffic is already dramatically increasing as individuals contact police, fire, and rescue personnel, as well as their loved ones. Therefore, Warning Notifications should not contain anything that would drive immediate and debilitating traffic loads into the PLMN (i.e., URLs or dialable numbers) unless required by regional regulation.

4.4 Granularity of the distribution

Requirements for the granularity of the distribution of Warning Notifications include:

– Based on the geographical information indicated by the Warning Notification Provider, it shall be possible for the PLMN operators to define the Notification Area based on their network configuration of the area coverage such as distribution of cells, Node Bs, RNCs, etc.

4.5 Support of Warning Notification Providers

PLMN operators shall, at a minimum, be able to support the following functionalities through interaction with Warning Notification Providers:

– Activation of Warning Notification delivery

It shall be possible for multiple Warning Notifications to be activated concurrently from one or more Warning Notification Providers.

– Cancellation of Warning Notification delivery

A cancellation is a command from the Warning Notification Provider to stop dissemination of a specific Warning Notification.

– Updating of Warning Notification delivery

Warning Notification Providers update a previous Warning Notification to provide new instructions/information to the PLMN operator. When the Warning Notification Provider updates a previous Warning Notification they provide an identifier that allows the PLMN operator to associate the updated Warning Notification with the previous Warning Notification.

Additional functionality may be required based on regulatory or operator policy requirements.

4.6 PWS-UE Requirements

4.6.1 General Requirements

PWS-UEs shall only be required to receive and present Warning Notifications in languages as presented by the Warning Notification Provider. Regional/regulatory requirements may require the Warning Notifications to be broadcast in multiple languages.

There shall be no requirement for language translation in the operator’s network or the UE.

It shall be possible for the Warning Notification to be displayed on the PWS-UE upon reception and without any user interaction.

It shall be possible for users to configure the behavior of a PWS-UE with regard to Warning Notification alerting and should allow at least volume adjustment.

The PWS-UE shall support a dedicated alerting indication (audio attention signal and a dedicated vibration cadence) and be distinct from any other device alerts and restricted to use for Warning Notification purposes. The User Interface shall support the ability for the user to suppress the dedicated audio attention signal and/or the dedicated vibration cadence when a Warning Notification is received.

The alerting indication for a specific Warning Notification shall continue until suppressed by users’ manual operation (e.g. by pushing keys). The frequency and duration of the continued alerting indication is mobile device implementation specific. This shall not suppress the alerting indication for subsequent Warning Notifications.

The PWS-UE shall automatically suppress duplicate notifications. A duplicate is a repetition of a previous notification as determined by unique parameters.

The PWS-UE shall not support any capabilities to forward received Warning Notifications, to reply to received Warning Notifications, or to copy and paste the content of Warning Notifications.

PWS-UEs should have the ability to present previously displayed Warning Notifications if requested by the user.

– PWS-UE shall be able to support concurrent reception of multiple Warning Notifications.

4.6.2 Support of non-Warning Notification capable UEs

Support of non-Warning Notification capable UEs is subject to regulatory requirements and/or operator’s policy.

4.6.3 Battery Life of PWS-UE

Battery life of the PWS-UE shall not be significantly reduced by PWS.

4.6.4 Enabling and disabling of Warning Notifications

The PWS-UE shall be configured to receive all Warning Notifications.

It shall be possible for users to disable (e.g., opt-out) presentation of some or all of the Warning Notifications, subject to regulatory requirements and/or operator policy. The user shall be able to select PWS-UE enabling/disabling options via the User Interface to disable, or later enable, the PWS-UE behavior in response to some or all Warning Notifications. Depending on the regional/regulatory requirements, the user shall be able to receive Warning Notifications in one or more selected languages.

Where regional or national regulations allow, the HPLMN operator shall be able to instruct the PWS-UE to ignore all Warning Notifications in the HPLMN and in PLMNs equivalent to it, by means of a setting on the USIM.

Where regional or national regulations pertaining to a VPLMN allow, the HPLMN operator shall be able to instruct the PWS-UE to ignore all Warning Notifications that are received whilst in this VPLMN, by means of a setting on the USIM, when the integrity of Warning Notifications in this VPLMN is known by the HPLMN operator to be compromised. This setting need not distinguish VPLMNs.

Subject to regional or national regulations, a PWS-UE in limited service state shall be able to receive and display Warning Notifications.

NOTE 1: Non-existing or empty USIM data files results in all Warning Notifications being presented to the PWS application.

NOTE 2: (void).

4.7 Roaming Requirements

It shall be possible for PWS-UEs that are enabled for Warning Notifications in the HPLMN to receive Warning Notifications from the VPLMN supporting PWS when roaming.

A PWS-UE that does not support the PWS requirements of the VPLMN’s PWS service may not receive Warning Notifications from that VPLMN.

Note: See section 4.9 for roaming impacts to PWS due to regional regulatory requirements.

4.8 Security Requirements

Security requirements are as follows:

– PWS shall only broadcast Warning Notifications that come from an authenticated authorized source.

The following requirements only apply when not roaming internationally:

– When required by regional or national regulations, the integrity of the Warning Notification shall be protected. If no such regulatory requirement exists, there shall be no integrity protection of Warning Notifications, and all Warning Notifications shall be presented to the PWS application on the PWS-UE.

– When required by regional or national regulations, the PWS shall protect against false Warning Notification messages. If no such regulatory requirement exists, there shall be no protection against false Warning Notifications, and all Warning Notifications shall be presented to the PWS application on the PWS-UE.

Note 1: These requirements are subject to regulatory policies.

NOTE 2: The authentication and authorisation of the source are outside the scope of 3GPP Specifications.

4.9 Regulatory Requirements

The PWS offered by a PLMN may be subject to PWS regional regulatory requirements and thus, the PWS offered may differ from PLMN to PLMN as well as from region to region within a PLMN.