According to CSRIC: "Adherence to the CAP standard alone does not guarantee that connected systems and equipment will be conformant with Part 11 Rules for EAS activation and display." CAP is a basic container for alert data, and practitioners have increasingly found that additional specificity has been required for the appropriate usage of CAP in various systems, including EAS. To resolve this issue, FEMA issued an IPAWS CAP profile, which describes how to create EAS messages specifically for the IPAWS system. Broadcast equipment manufacturers, as represented by ECIG (EAS-CAP Industry Group) have offered further specificity on how CAP-formatted messages can be used to generate part 11-compliant EAS messages. The IPAWS CAP profile was developed by integrating the requirements related to three federal warning-delivery systems: The broadcast EAS as recommended by the ECIG, the NOAA non-weather emergency message (NWEM), and CMAS for cellular telephones.

Again, referring to the CSRIC document: In May 2010, the ECIG published guidelines "intended to further reduce the areas of uncertainty in how an alert will be presented to the public via CAP/EAS so that originators and distributors of alerts can deliver the intended message to the public, regardless of the vendors or platforms involved." The CSRIC document was published in September 2010, and even at that time, there was still some room for interpretation of CAP messages. From the same document: "Public warnings intended for transmission over EAS can be encoded in CAP messages in various ways. As both CAP v1.2 and CAPv1.2 IPAWS Profile (v1.0) make use of several free-form text elements and several optional elements, there is ample opportunity for a CAP message rendered by one CAP-to-EAS device to differ when rendered by another vendor's device. There can also be a difference between what the originator intended for an alert, and what the alerts contain, when broadcast by CAP/EAS devices."

It is clear there are still issues to be resolved prior to the real implementation of CAP at the end of September 2011. However, according to the same industry source I referred to earlier, the issues are being resolved, and indeed most if not all will be resolved by the end of March of 2011. Manufacturers are working in earnest with FEMA so the new deadline can be met. Broadcasters should plan for capital purchases this year so they can implement CAP/EAS by the deadline.

Irwin is transmission systems supervisor for Clear Channel NYC and chief engineer of WKTU, New York. Contact him at doug@dougirwin.net.