Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
A Current Alert and Warning Systems and Their Characteristics The alert and warning ecosystem includes a network of government and industry-supported systems and dissemination channels. A brief history of government-mediated systems is outlined below as well as a discussion of the characteristics of each dissemination channel. GOVERNMENT-MEDIATED ALERT AND WARNING SYSTEMS Alert and warning systems have evolved over time to reflect new types of hazards or technologies, moving from various television and radio broadcast technologies to now include cell broadcast. (See Figure A.1 for the evolution of emergency broadcasting.) However, this evolution has occurred very slowly and has often stemmed from a major hazards event. Furthermore, alert and warning systems have not kept up with new technologies. For example, the 2006 Warning, Alert, and Response Network (WARN) Act prompted the first significant changes to national alerting systems since the mid- 1990s. FIGURE A.1 Evolution of emergency broadcasting. PREPUBLICATION COPY â SUBJECT TO FURTHER EDITORIAL CORRECTION 61
The WARN Act in combination with Executive Order 134071 created the Integrated Public Alert and Warning System and WEA (then known as the commercial mobile alert system). The goal of this system was to integrate various alerting systems, the Emergency Alert Systems, National Warning System, Wireless Emergency Alert (WEA) system, and the National Oceanic and Atmospheric Administration (NOAA) Weather Radio All Hazards into one modern network. The new system also looks to take advantage of newer forms of communication such as cellular telephony, satellite and cable television, and mobile devices. Additionally, the Integrated Public Alert and Warning System (IPAWS) allows for alerts to be originated by various government organizations and officials at the federal, state, local, and tribal level, and allows a single message to be transmitted to the various alert platforms. The IPAWS open platform for emergency managers uses an IP-based network that allows alert originators (AO) to submit alerts to a server that aggregates and disseminates these alerts to the proper systems. Figure A.2 illustrates the IPAWS Architecture. An XML-based data format, Common Alerting Protocol (CAP), normalizes alert data across threats, jurisdictions, and warning systems. CAP data structure is compatible with existing alert formats but also builds on new capabilities, such as those needed for WEA. IPAWS significantly updated geotargeting capabilities. Older alert systems relied on FIPS codes that were assigned by county and a few larger cities, making the finest grain of geotargeting alerts countywide. IPAWS allows flexible geotargeting that can more narrowly target areas using GIS data by entering polygon coordinates to outline the at-risk area. Other new capabilities include multilingual and multi-audience messaging; phased and delayed effective times and expirations, enhance message update and cancellation features, template support, digital encryption and signature capabilities, and facilities for digital images, audio, and video. As an example, consider the following emergency situation: A storm produces large amounts of rain, water level sensors in a local creek in Boulder County indicate rapid onset of a flooding event, and the NWS issues a flash flood warning for a polygonal area that the storm will hit hardest. The local emergency management coordinator, who serves as an Alert Originator (AO), crafts an alert. The AO submits this alert (in the form of a CAP message that includes the type of event and area impacted) to IPAWS, which then after authenticating the message sends it out to the appropriate Emergency Alert System (EAS), WEA, NOAA radio, and other disseminators. In the case of WEA, the cell carriers would use cell broadcast to transmit the alert to a set of cell towers that correspond to the specified area. Emergency Alert System EAS is a national warning system in place to enable the president to speak to the US within 10 minutes and serves as a way to alert the public of hazard events. EAS messages are transmitted via AM, FM, broadcast television, cable television, land mobile radio services, and more recently, digital television, satellite television, digital cable, and satellite and digital radio. Messages, which have no length limits, must contain a SAME headerâwhich denotes originator, a short description of the event, date/time issues, and identification of originating stationâan attention signal, an audio announcement, and a digitally encoded end-of-message marker. There are currently 80 types of events for the use of EAS. 1 Executive Order. No. 13407, 2006, pp. 1226â1228. PREPUBLICATION COPY â SUBJECT TO FURTHER EDITORIAL CORRECTION 62
FIGURE A.2 The IPAWS architecture. SOURCE: http://www.fema.gov/pdf/emergency/ipaws/architecture_diagram.pdf. Wireless Emergency Alerts As required under the WARN Act, the Commercial Mobile Service Alert (the original name for WEA) Advisory Committee (CMSAAC) was established in late 2006 by the Federal Communications Commission (FCC) to engage stakeholders in the development of initial policy and procedures for one component of that national systemâthe use of cellular telephones for alerts. CMSAAC, composed of representatives from service providers, handset vendors, emergency personnel, and industry groups, issued its first report in 2007, defining the Commercial Mobile Alert Serviceâs (CMASâs) basic system architecture and establishing technical standards and operating procedures.2 In the original FCC rules, messages were restricted in length to 90 characters and explicitly prohibited the inclusion of URLs. Messages were divided into three categories, Presidential alerts, imminent threat alerts, and child abduction alerts. WEA is an opt-out system; cellular customers would receive imminent threat alerts and AMBER Alerts unless they opted out. It will not be possible to opt out of receiving presidential alerts. Carrier participation is voluntary; to date the major cellular carriers have signed on to the program. WEA-compatible handsets will use a special alert tone for WEA messagesâto draw attention to 2 The recommendations of the CMSAAC appear in its draft report: Commercial Mobile Service Alert Advisory Committee, 2007, Commercial Mobile Alert Service Architecture and Requirements, PMG-0035, FCC, Washington, D.C.; and in FCC, 2008, Notice of Proposed Rule Making on The Matter of Commercial Mobile Alert System, Public Safety Docket No. 07-287. PREPUBLICATION COPY â SUBJECT TO FURTHER EDITORIAL CORRECTION 63
the messages and to distinguish them from other messages. This tone will override the normal ringer- volume settings. A unique vibration cadence will also be used to reach hearing-impaired users. The message format defined for WEA was based on prior work to define a standard alert-message format, the Common Alerting Protocol. This format, which specifies the geographical area affected, the recommended action, an expiration time, and the sending agency, is designed to allow messages to increase interoperability with other alert systems. Additionally, the text of the WEA itself (i.e., not including the header) was originally limited to 90 characters. WEA uses cell broadcast technology known as short message service-cell broadcast (SMS-CB) to transmit messages. Cellular broadcast offers two principal advantages over SMS. First, a single broadcast message can reach each active cell phone within range of a given cellular tower, reducing the network capacity required for message delivery compared to that required for sending messages to each subscriber. Moreover, because cellular broadcast uses a data channel separate from that used for other messages and calls, it is unaffected by network congestion. A September 2016 update to the rules for WEA provided much improved capabilities.3 These include: ï· Increase in message length 360 characters for 4G LTE and future networks. ï· Inclusion of embedded phone numbers and URLs. ï· Deliver to a more narrowly defined geographic area. ï· Created a new class of alerts, Public Safety Message, to convey essential and recommended actions (i.e. emergency shelter locations or boil water order). ï· Require providers to support transmission of Spanish-language alerts. Opt-in Alert and Warning Systems Jurisdictions have leveraged the ability to delivery messages via SMS and email by purchasing third party systems that allow for opt-in registration. Emergency management organizations market these systems to the public, who register to receive either SMS or emails about a range of topics. These types of systems are also often used for location-of-interest alerting, such as school systems and universities; some utilities also use these systems to alert subscribers of system outages. Both SMS-capabilities as well as only reaching those who registered ahead limit these systems. OTHER ALERT AND WARNING SYSTEMS Several private organizations have built various alert and warning systems within their communication networks. This includes various weather applications that allow users to receive notifications when weather alerts are issued by the NWS or Google.orgâs overlay of various alert and warning on its maps. CHARACTERISTICS OF EMERGENCY MESSAGE DISSEMINATION CHANNELS There are a wide variety of alert and warning dissemination channels available to public message providers in the U.S. These are listed and evaluated in terms of the speed at which each can deliver the message, the coverage area that each channel reaches, the degree to which the channel reaches everyone 3 FCC, FCC 16-127, adopted September 29, 2016, https://apps.fcc.gov/edocs_public/attachmatch/FCC-16- 127A1.pdf. PREPUBLICATION COPY â SUBJECT TO FURTHER EDITORIAL CORRECTION 64
versus only people in focused locations, and the extent to which each channel can provide detailed information in the following table. An inspection of this table illustrates that each communication channel has both advantages and shortcomings. The key shortcoming of WEA messages (limited to 90 characters at the time the table was prepared) was that those messages lacked message comprehensiveness. Message Dissemination Channels Speed1 Coverage2 Concentration3 Comprehensiveness4 Route alerting Slow Limited Concentrated High Loudspeakers and public Fast Limited Concentrated Medium address (PA) systems Wireless Emergency Alerts Very Fast Widespread Dispersed Very Low (WEA) Wireless communications Very Fast Widespread Dispersed Very Low (SMS) Radio Moderately Fast Widespread Dispersed High to Low Television broadcast Moderately Fast Widespread Dispersed Very High to Medium Television message scrolls Moderately Fast Widespread Dispersed Low Newspaper Very Slow Widespread Dispersed Very High Dedicated tone alert radios Very Fast Limited Concentrated High Tone alert and NOAA Fast Widespread Dispersed High Weather Radio Text Telephone Fast Widespread Dispersed Low (TDD/TTY) Reverse telephone Fast Limited Dispersed High distribution systems Audio sirens and alarms Fast Limited Concentrated Very Low 1. The rapidness of the system to reach its targeted audience ranges from Very Fast (less than 10 minutes to Slow (greater than 60 minutes). 2. Coverage is the size of the area that can be reached by the channel (Widespread, a large area, or Limited, a small area). 3. Concentration is the degree to which the people that the channel reaches are co-located or dispersed (Concentrated, the message is delivered to targeted locations only or Dispersed, the message has the potential to reach everyone). 4. Comprehensiveness, or the ability to convey the content needed for effective response classes, used in this table are as follows: Very Low (alerting only); Low (very little information conveyed); Medium (many but not all essential contents conveyed); High (all relevant content conveyed); Very High (all relevant content conveyed with enhanced graphics). SOURCE: Sorensen, J. and D. Mileti. 2014. Protective Action Initiation Time Estimation for Dam Breaches, Controlled Dam Releases, and Levee Breaches or Overtopping. Paper prepared for U.S. Army Corps of Engineers Institute for Water Resources, Risk Management Center. Davis, CA). PREPUBLICATION COPY â SUBJECT TO FURTHER EDITORIAL CORRECTION 65