Authority-to-Citizen Alert (atoca)

Last modified: 2012-11-13


Real-Time Applications and Infrastructure Area Directors

Real-Time Applications and Infrastructure Area Advisor

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Description of Working Group:

There are a variety of mechanisms that authorities have available to notify citizens and visitors during emergency events. Traditionally, they have done so with broadcast networks (radio and television). For commercial mobile devices, broadcasting services such as the Public Warning System (PWS), the Earthquake and Tsunami Warning System (ETWS), and the Commercial Mobile Alert System (CMAS) are standardized and are in various stages of deployment. The Internet provides another way for authority-to-citizen alerts to be sent, but it also presents new challenges. While there are some existing layer 2 mechanisms for delivering alerts, the work in this group focuses on delivering alerts to IP endpoints only.

The general message pattern that this group is intended to address is the sending of alerts from a set of pre-authorized agents (e.g., governmental agencies) to a large population without undue impacts on the networks serving that population. In particular, the message pattern specified should avoid congestion and other denials of service.

The goal of this group is not to specify how originators of alerts obtain authorization, but rather how an ATOCA system can verify authorization and deliver messages to the intended recipients. A critical element of the work are the mechanisms that assure that only those pre-authorized agents can send alerts via ATOCA, through an interface to authorized alert distribution networks (e.g., iPAWS/DM-Open in the U.S.).

The ATOCA effort is differentiated from and is not intended to replace other alerting mechanisms (e.g., PWS, CMAS, ETWS), as the recipients of ATOCA alerts are the wide range of devices connected to the Internet and various private IP networks, which humans may have"at hand" to get such events, as well as automatons who may take action based on the alerts. This implies that the content of the alert contains some information, which is intended to be consumed by humans, and some which is intended to be consumed by automatons.

Ideally, the alerts would contain, or refer to media other than text media (e.g., audio and/or video). The initial work in the group is focused on small messages, which may be mechanically rendered by the device in other forms (text to speech for example). Future work in the group may investigate rich media.

In situations of a major emergency there could be scenarios where there are multiple alerts generated that may require that a priority mechanism (defined by alert originator policy) has to be used. The work on a resource priority mechanism is out of scope of the initial charter, but may be revisited at a later date.

Which devices should get alerts is primarily driven by location. The first set of recipients that must be catered for are those within the area identified by the alert originator to be affected by the emergency event. In many jurisdictions, there are regulations that define whether recipients/devices within the affected area have opt-in or opt-out capability, but the protocols ATOCA will define will include both opt-in and opt-out mechanisms. The group will explore how to support both opt-in and opt-out at the level of communication protocols and/or device behavior.

Another class of recipients that are in scope of the work are explicit opt-in subscriptions which ask for alerts for a specified location, not necessarily the physical location of the device itself. An example of such a subscription would be 'send me alerts for location x' (previously determined as the location of interest). This work may build on existing IETF GEOPRIV location work.

There are efforts in other fora on early warning, which will be considered in this effort. For example, we expect to make use of the OASIS Common Alerting Protocol (CAP) for the encoding of alerts. OGC, ATIS, TIA, ITU-T, ETSI and 3GPP also have alert efforts underway, and consultation with these efforts will be undertaken to avoid unnecessary duplication of effort and also to avoid unintentional negative impacts on the networks. Of course, existing protocols for delivering messages (e.g., SIP, XMPP, or SMTP) will be the basis for the message delivery system of this working group. Any service discovery mechanisms defined by the group are expected to reuse existing discovery frameworks.

The security implications of mechanisms that can send alerts to billions of devices are profound, but the utility of the mechanism encourages us to face the problems and solve them. In addition, the potential performance and congestion impacts to networks resulting from sending alert information to billions of devices must be considered and solved if such a service is implementable. To avoid manual configuration of servers distributing alerts a discovery mechanism will be specified.

Goals and Milestones

Aug 2012 Call for proposals for Secure Alerting Format
Sep 2012 Individual contribution(s) made for Secure Alerting Format draft
Oct 2012 Call for WG consensus on adopting a Secure Alerting Format draft into the WG
Oct 2012 First WG draft of Secure Alerting Format
Feb 2013 Submit Secure Alerting Format draft to the IESG as Proposed Standard

No Internet-Drafts

No Request for Comments

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