The Cover PagesThe OASIS Cover Pages: The Online Resource for Markup Language Technologies
Advanced Search
Site Map
CP RSS Channel
Contact Us
Sponsoring CP
About Our Sponsors

Cover Stories
Articles & Papers
Press Releases

XML Query

XML Applications
General Apps
Government Apps
Academic Apps

Technology and Society
Tech Topics
Related Standards
Created: February 26, 2004.
News: Cover StoriesPrevious News ItemNext News Item

Common Alerting Protocol Version 1.0 Approved by OASIS Emergency Management TC.

Update 2005-05-19: The OASIS Emergency Management TC announced the release of a V1.1 Committee Draft of the "Common Alerting Protocol" specification for public review. CAP is a general XML format for exchanging all-hazard emergency alerts and public warnings over multiple networks. TC members are also participating in the development of an XML-based Emergency Data Exchange Language (EDXL), intended to provide a broader integrating framework for a wide range of emergency data exchange standards and application types. See "OASIS Advances Common Alerting Protocol and Emergency Data Exchange Language."

Update 2004-04-07: On April 01, 2004 OASIS announced that the Common Alerting Protocol Committee Draft version 1.0 of February 10, 2004 approved by the TC and balloted to the OASIS membership had resulted in this Committee Draft being approved as an OASIS Standard. A new "CAP 1.0 Fact Sheet" has also been released.

[February 26, 2004] In February 2004, members of the OASIS Emergency Management Technical Committee approved a Committee Draft specification for the Common Alerting Protocol Version 1.0 and recommended its advancement for approval by OASIS as an OASIS standard.

The Common Alerting Protocol (CAP) is "a simple but general format for exchanging all-hazard emergency alerts and public warnings over all kinds of networks. CAP allows a consistent warning message to be disseminated simultaneously over many different warning systems, thus increasing warning effectiveness while simplifying the warning task. CAP also facilitates the detection of emerging patterns in local warnings of various kinds, such as might indicate an undetected hazard or hostile act. And CAP provides a template for effective warning messages based on best practices identified in academic research and real-world experience."

The OASIS Emergency Management Technical Committee was chartered to "design, develop, and release XML Schema-based standards that begin to solve the real-world problems of incident preparedness, response, and emergency management; these standards are not only to provide a framework for data exchange, but also for functionality and service accessibility, all with the common goal of seamless application and data interoperability. The Emergency Management TC's scope includes: unified incident identification; emergency GIS data accessibility and usage; notifications methods and messages; situational reporting; source tasking; asset and resources management; monitoring and data acquisition systems; staff, personnel and organizational management."

Bibliographic Information

Common Alerting Protocol, Version 1.0. OASIS Technical Committee Draft. 10-February-2004. Document identifier: 'emergency-CAP-1.0'. 31 pages. Section 3.4 presents the XML Schema. Edited by Art Botterell (Partnership for Public Warning). Produced by members of the OASIS Emergency Management TC.

CAP Summary

"The Common Alerting Protocol (CAP) provides an open, non-proprietary digital message format for all types of alerts and notifications. It does not address any particular application or telecommunications method. The CAP format is compatible with emerging techniques, such as Web services, as well as existing formats including the Specific Area Message Encoding (SAME) used for NOAA Weather Radio and the Emergency Alert System, while offering enhanced capabilities that include:

  • Flexible geographic targeting using latitude/longitude shapes and other geospatial representations in three dimensions
  • Multilingual and multi-audience messaging
  • Phased and delayed effective times and expirations
  • Enhanced message update and cancellation features
  • Template support for framing complete and effective warning messages
  • Facility for digital encryption and signature capability
  • Facility for digital images and audio

Key benefits of CAP will include reduction of costs and operational complexity by eliminating the need for multiple custom software interfaces to the many warning sources and dissemination systems involved in allhazard warning. The CAP message format can be converted to and from the 'native' formats of all kinds of sensor and alerting technologies, forming a basis for a technology-independent national and international 'warning internet'."

The National Science and Technology Council report on 'Effective Disaster Warnings' released in November, 2000 recommended that 'a standard method should be developed to collect and relay instantaneously and automatically all types of hazard warnings and reports locally, regionally and nationally for input into a wide variety of dissemination systems.'

An international working group of more than 130 emergency managers and information technology and telecommunications experts convened in 2001 and adopted the specific recommendations of the NSTC report as a point of departure for the design of a Common Alerting Protocol (CAP). Their draft went though several revisions and was tested in demonstrations and field trials in Virginia (supported by the ComCARE Alliance) and in California (in cooperation with the California Office of Emergency Services) during 2002 and 2003. In 2002 the CAP initiative was endorsed by the national non-profit Partnership for Public Warning, which sponsored its contribution in 2003 to the OASIS standards process.

The primary use of the CAP Alert Message is to provide a single input to activate all kinds of alerting and public warning systems. This reduces the workload associated with using multiple warning systems while enhancing technical reliability and target-audience effectiveness. It also helps ensure consistency in the information transmitted over multiple delivery systems, another key to warning effectiveness.

A secondary application of CAP is to normalize warnings from various sources so they can be aggregated and compared in tabular or graphic form as an aid to situational awareness and pattern detection. Although primarily designed as an interoperability standard for use among warning systems and other emergency information systems, the CAP Alert Message can be delivered directly to alert recipients over various networks, including data broadcasts. Location-aware receiving devices could use the information in a CAP Alert Message to determine, based on their current location, whether that particular message was relevant to their users. The CAP Alert Message can also be used by sensor systems as a format for reporting significant events to collection and analysis systems and centers..." [from the Verxion 1.0 specification, Section 1]

Attestations of CAP Use

  • Art Botterell, on behalf of the Partnership for Public Warning (PPW): "The Partnership for Public Warning (PPW), an OASIS member organization in good standing, is pleased to certify its successful use of the CAP 1.0 committee draft specification in demonstrations and field trials by a number of its member organizations and companies..."

  • Eliot Christian, on behalf of the U.S. Department of the Interior: "The U.S. Geological Survey, a bureau of the Department of the Interior, disseminates reviewed earthquake information. In California, this information is turned into alert messages in the CAP 1.0 format through the Emergency Digital Information System (EDIS)."

  • Gary A Ham, on behalf of the Disaster Management Program: "Disaster Management Interoperability Services (DMIS) has implemented an information sharing interface that allows the interchange of CAP messages between multiple different commercial and government alerting applications where those applications adhere to DMIS authorization and security rules. has implemented the ability to retrieve and display CAP messages from multiple sources using the DMIS interoperability interface."

Common Alerting Protocol (CAP) Over XMPP

An experimental draft has been published by describing the use of the Extensible Messaging and Presence Protocol (XMPP) for instant messaging as a transport for CAP alerts.

"JEP-01xx: Common Alerting Protocol (CAP) over XMPP." By Peter Saint-Andre and Boyd Fletcher. Standards-Track JEP (Experimental). Jabber Enhancement Proposal, copyright (c) 1999 - 2004 by the Jabber Software Foundation (JSF). (Initial) Version 0.1 (2004-02-23). The preferred venue for discussion of this document is the Standards-JIG mailing list. "The Common Alerting Protocol (CAP) is an open format for alerts and notifications, defined by OASIS [2]. CAP was developed to address the call, published in a (U.S.) National Science and Technology Council report, for 'a standard method ... to collect and relay instantaneously and automatically all types of hazard warnings and reports'. Given that the Extensible Messaging and Presence Protocol (XMPP) provides a near-real-time transport mechanism for structured information, and that CAP is defined as an XML data format, it makes sense to define a way to transport CAP information over XMPP. Such a method is defined herein... Because the alerts and notifications structured via CAP require a 'push' medium, they SHOULD be sent via the XML <message/> stanza defined in XMPP Core. The message could be: (1) sent directly from the sender to a recipient or list of recipients (which might include a Multi-User Chat room) via standard XMPP messaging, or (2) published to a list of subscribers via Publish-Subscribe. Both methods are described..." [cache]

CAP Implementations

According to a CAP 1.0 - Fact Sheet, CAP implementations have been demonstrated by agencies and companies including: Department of Homeland Security, National Weather Service, United States Geological Survey, California Office of Emergency Services, Virginia Department of Transportation, Capital Wireless Integrated Network (CapWIN), GeoDecisions, Inc., E Team, Blue292, Warning Systems, Inc., Comlabs, Inc., mobileFoundations, Ship Analytics, MyStateUSA, IEM, Inc., Hormann America, Inc., Oregon RAINS, and NDS, Ltd. Some examples follow.

  • The National Weather Service (US Dept of Commerce, National Oceanic and Atmospheric Administration)"has an experimental feed of all its watches, warnings and advisories in CAP format," according to Art Botterell. See the document "Experimental Listings of Watches, Warnings, and Advisories," which "provides access to NWS watches, warnings and advisors, listed by state in three different formats. Select a state name to view a list of active alerts in your web browser. These files are updated about every two minutes. Select a state name to see the list for a state. RSS and CAP/XML lists are provided to aid the automated dissemination of this information. More information on RSS and CAP/XML formats/feeds... NWS Alert CAP messages contain the county FIPS code information for the affected county in the cap:geocode tags. Additional cross references to NWS forecast zones is available..."

  • The State of California, Governor's Office of Emergency Services, Emergency Digital Information Service (EDIS) "delivers official information about emergencies and disasters to the public and the news media in California." EDIS has public feed for EDIS bulletins in CAP format at See example #1, example #2 from 2004-02-26.

  • Roland Lussier of Comlabs (Melbourne, Florida, USA) reports that Comlabs is "a current provider of the National Warning System. Our new system is called EMnet and is satellite based. Our EMnet and EMnet/EAS system has warning information from both the civil and NWS in the stream. An EMnet node can generate a CAP XML file when an alert is received. It is interoperable and in use today in nine states..."

  • The Regional Alliances for Infrastructure and Network Security (RAINS) emergency alert system implemented by the State of Oregon uses the Common Alerting Protocol (CAP). "RAINS continues to work closely with the 9-1-1 centers in the Portland Metro area to integrate an alerting framework with the existing CAD systems (Computer Assisted Dispatch). Currently [2004-02], when an emergency operator dispatches fire or security services within the Portalnd Metro area, the information details of the call request are converted into CAP format and distributed to the 'RAINS Connect & Protect' system via web services. Once received, C&P filters and targets those messages for delivery to schools, businesses, hospitals, etc. To date, RAINS has processed more than 87,000 CAD dispatches into CAP format. From one 9-1-1 center alone we receive approximately 500 CAP incidents per day. Since the messages are in a hightly structured format, (CAP), we are able to quickly apply our filtering process by event type, severity, certainty, category, location (geocodes & lat / long), etc., and deliver only the incident types that matter most to the targeted user base..." Information from Frank Tycksen; see also "Emergency Alert System Yields Valuable Lessons," by Brian Robinson, in Federal Computer Week (February 23, 2004).

  • Kon Wilms (NDS Americas Inc.) reported on 2004-02-17 that NDS "has a product called AlertStorm which delivers alerting and other media via digital television signals using CAP and other protocols/data formats. Reception is wireless, and emergency managers and others receiving the feed make use of an antenna and PC receiver card (internal or USB) to receive the data feeds. We are operational in production and trial in 7 states around the country on a number of DTV/HDTV stations (mostly PBS), some with a footprint of 60 miles, some with statewide coverage. Many of the systems have been in operation since around 1999, and are being migrated to use CAP exclusively for alerting messaging. We will also be demonstrating at NAB2004 in Las Vegas with a live station feed..." See the brochure.

Principal references:

Hosted By
OASIS - Organization for the Advancement of Structured Information Standards

Sponsored By

IBM Corporation
ISIS Papyrus
Microsoft Corporation
Oracle Corporation


XML Daily Newslink
Receive daily news updates from Managing Editor, Robin Cover.

 Newsletter Subscription
 Newsletter Archives
Bottom Globe Image

Document URI:  —  Legal stuff
Robin Cover, Editor: