ITU-T X.1303 BIS PDF

This Recommendation defines the common alerting protocol (CAP) - version 1.2 - which 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 facilitates the detection of emerging patterns in local warnings of various kinds, such as those that might indicate an undetected hazard or hostile act. CAP provides a template for effective warning messages based on best practices identified in academic research and real-world experience.

CAP provides an open, non-proprietary digital message format for various types of alerts and notifications. CAP provides the following capabilities:

• 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;

• compatible with digital encryption and signature capability; and

• facility for digital images and audio.

CAP provides 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".

This Recommendation also provides both an XML schema definition (XSD) schema and an abstract syntax notation one (ASN.1) specification for the common alerting protocol.

NOTE - The ASN.1 specification defines the same message information content and XML encoding as that defined by the XSD schema, but permits a compact binary encoding and the use of ASN.1 as well as XSD tools for the generation and processing of CAP messages.

This Recommendation is technically equivalent to the OASIS Common Alerting Protocol v.1.2.