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Location-based Emergency Alerting to Mobile Devices:  Progress in 2007

Judy Harkins, Technology Access Program
Gallaudet University
December 2007

Emergency alerting is again in the news in 2007, after tragedies such as the Virginia Tech shootings and the fires in southern California highlighted the need for fast information to specific locations.  Emergency managers, employers and university personnel want to reach people in specific locations with current information about that location.

This year, the wireless industry and the FCC began planning a new nationwide system that will allow emergency managers to send alerts to cellular mobile devices -- cell phones and pagers -- based on the specific location of the emergency at that time.  In other words, the cellular provider will “broadcast” a message from emergency managers to every subscriber in a designated area, and not to subscribers in other areas.  The name of the planned nationwide service for wireless alerts is the Commercial Mobile Alert Service (CMAS).  It is slated for development over the next few years.

CMAS versus Email Alerts

The planned CMAS is different from email alert services.  Many people already subscribe to one or more email alert services from their local government, local news media, commercial internet-based services, and some employers and schools.  You may be able to select specific areas and receive alerts only about those areas.  In my area, for example, Washington DC’s alert system (Alert DC) allows you to choose by neighborhood and type of event you want to know about.   Gallaudet University’s service issues alerts only about issues pertaining to students and employees of the university. 

For mobile device users, these messages typically come in as email.  The message may provide a link to a website with more information.  For people who only use voice and not data services, some services also provide text messages to voice phones using Short Messaging Service (SMS).

All of these informational services require that people sign up for them, usually on a website.  But what if you are traveling outside of your home areas?  Few people bother to register for many services in their area or to areas where they are traveling.  What about people who don’t know about these alert services or don’t bother to sign up?  What about people who do not have access to the Internet? 

This is what’s different about the new planned nationwide CMAS service:  The Commercial Mobile Alert Service is intended to fill some of those gaps.  It will reach more people.  You will not have to sign up for service.  It will not rely on an email server.  It will not get stuck in a spam filter.  However, you will probably want to keep your email service as a supplement, as you will probably get more detailed information that way.

The 2006 WARN Act

In 2006, Congress passed a law called the Warning, Alert and Response Network (WARN) Act.  Originally a bill to set up a comprehensive national alerting system, the bill was cut back during its development to focus only on cell phone and pager networks.  The WARN Act sets up a nationwide system for alerting to mobile devices (cell phones, PDAs, and pagers) without requiring anyone to sign up or pay additional fees.  The law sets a timetable for developing the new system.  However, service providers are not required by law to participate, with one exception:  if the President of the United States sends a message, all service providers must broadcast the message. 

The law mandated an advisory committee to develop technical characteristics and some legal disclosure language.  The Commercial Mobile Service Alert Advisory Committee was composed primarily of industry representatives, with some emergency managers and public interest representation as well.  The committee submitted its report to the FCC in October, 2007, just ten months after the committee was set up.  Marcia Brooks of WGBH/National Center for Accessible Media and I were active participants on this committee, in the User Needs Group.

The Plans for CMAS

Based on the report to the Commission, and subject to change, the following are planned characteristics of the service:

  • The service is for “heads up” alerting, not a detailed set of instructions.  You will be expected to seek more information from television, websites, and other media.
  • The messages will be short; 90 characters at first.  This is because the system had to accommodate the lowest common denominator in message length.  Some carriers can technically provide longer messages, but this is a one-size-fits-all, nationwide system. 
  • Example message: 

Tornado warning in this area.  Take shelter until 6:00 PM EDT.  NWS.

  • The messages will be transmitted only in text (at least in the first generation).
  • To get users’ attention quickly, there will be a unique audio tone for people who use ring signals, and a unique vibration pattern for devices that have vibrating signals and are set to vibrate
  • CMAS is for serious events.  For an alert to be sent, there must be an “imminent threat to life and property”; or an AMBER alert (child abduction emergency).
  • Mobile subscribers can elect to turn off the alerts  The advisory committee recommended that users have choices:  to be able to turn off all alerts, or just AMBER alerts, or receive only the most serious emergency alerts.
  • Mobile subscribers will not pay any extra fees for the service
  • It is not interactive, it is not SMS, and it is not email.  It is a separate and unique service.

Some questions and answers:

Who sends the alerts?

A government’s emergency management is responsible for writing the alerts.  The carrier simply passes the messages through to your device on a secure system designed to avoid spam or other false messages.  The abbreviation for the agency that issued the alert is included in the message so you will know who sent it.

If I have a data-only plan, will I receive alerts?

Yes, if your service provider participates in CMAS.

If my device is turned off, or if I am using it to call or send messages, will I receive alerts?

No.  This is (in my opinion) a shortcoming of the system.  Emergency managers may elect to re-send messages, and the mobile device will not display duplicates of the same message (unlike email). 

Will I have to buy a new device once the system is set up?

Probably yes because new software is needed in the handset or pager. You will need to check when buying a device to see if it will receive CMAS alerts.  Over time it is expected that all mobile devices will be capable of receiving CMAS alerts.

How good will the coverage be?

For participating carriers, the coverage will probably be better than most data services, more like voice coverage.

Will the message give a website or phone number for more information?

No.  Phone numbers and web information will not be carried in the message because of industry concerns that the network would be overloaded if everyone tried to access additional information using their wireless device at the same time.

Why just text?  What about video or voice alerts?

The first generation of the system will provide text alerts.  Our committee included accessibility recommendations for all of the possible modes, but the details for an audio or video mode have not been specified.  The industry concern is keeping the service as “lightweight” as possible so as not to clog the networks during emergency, and also to establish a viable service based on text before moving on to other media.

How will I know when a CMAS emergency message has arrived?

If your device is set to vibrate, it will vibrate in a pattern that’s unique to the CMAS.  If it is set to ring, it will have a unique CMAS tone and pattern.  (The tone will probably be like the EAS tone – familiar to many people from years of use.  The proposed tone meets general guidelines for hard of hearing phone users, within the constraints of handset manufacturing – the tones will be below 1000 Hz, more than one tone, in a varying on-off pattern.)

How specifically will the planned system target geographic location?

At first the system will probably alert everyone in a county about an emergency in that county.  This wide area is not useful enough to emergency managers in many cities, and emergency management experts on the advisory committee urged the industry to improve the geo-targeting to smaller areas, for example, to part of a city.  This will require some additional technical development.  The FCC is likely to review this issue further.

Where can I get more information?

Stay tuned to TDI World for information as the system develops.  

The FCC will issue a Notice of Proposed Rulemaking.  Mass news media will probably include stories about the plans for the system.  When CMAS becomes available, each carrier is required to disclose to consumers whether they carry CMAS alerts.


Funding for this article has been provided by the National Institute on Disability and Rehabilitation Research (NIDRR), U.S. Department of Education, under grant H133E040013.  However, the contents do not necessarily reflect the policy of the Department of Education and you should not assume endorsement by the Federal Government.

Thanks to Marcia Brooks of WGBH/NCAM and Paula Tucker of Gallaudet for reviewing a draft of this article.

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