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At 1:55 p.m. on May 7, your phone will make an extremely annoying noise

Impossible-to-ignore emergency alerts are coming to your phone whether you want them or not. You can't opt out
On some mobile devices, the new emergency alert signals may actually override your user settings and make themselves heard even if your phone is set to silent

It's called the Canadian Alerting Attention Signal.

You might have heard it on your radio or television in connection with Amber Alerts or other warnings about life-threatening situations.

In technical jargon, it's a series of square wave tones alternating between 440 Hz/659 Hz/3136 Hz and 932 Hz/1046 Hz/3136 Hz.

It's about as annoying a sound as you're ever likely to hear, designed to get your undivided attention.

On Monday, May 7 at exactly 1:55 p.m., those impossible-to-ignore square wave tones will blare from mobile phones and other compatible wireless devices across Ontario.

Lauren Perry, Sault Ste. Marie's emergency management coordinator, says it will be part of annual test alerts done by broadcasters during Emergency Preparedness (EP) Week each May, except this year, wireless service providers will participate for the first time.

"Our hope is this will be a reminder to all our community members to see how prepared they might be," Perry told her City Council during a presentation this week.

"If we all received an alert in the next five minutes that there was an emergency in our community, would you have an emergency kit ready to go?" Perry asked.

"Do all members of your family know what to do? Are you aware of the immediate risks in our community and the actions you can take to be safer? Now is the time to prepare, before an emergency occurs."

The new wireless emergency alerts will look like text messages but actually will be distributed using a different technology.

"Emergency alerts are sent via cell broadcast distribution," says the Alert Ready website.

"Cell broadcast is a mobile technology that allows messages to be broadcast to all compatible wireless devices within a designated geographical area. Cell broadcast is designed for simultaneous message delivery to multiple users in a specified area, and is not affected by network congestion because it uses dedicated part of the network, separate from that used for traditional voice and data traffic," the website says.

"Cell broadcast can be compared to radio broadcast. Radio towers broadcast music to people in defined geographic areas as long as the individuals can pick-up the broadcast signal and have their radios turned on. Cell broadcast messages similarly are delivered to those compatible wireless devices that are within range of cell towers and antennas in the designated area. Location services do not have to be enabled on your wireless device to be able to receive alerts."

If an emergency alert is issued while your phone is turned off, it will be displayed when your device is turned on, so long as the alert is still active.

If your phone is set to silent, you probably won't hear the alert sound, but on some devices you might.

"A compatible wireless device that is set to silent will display an emergency alert, but you might not hear the emergency alert sound. The emergency alert sound will usually play at whatever the current volume setting is on the wireless device, so if your wireless device is set to silent, no sound will accompany the emergency alert message. However, this behaviour can differ depending on your wireless device and in some instances the alert sound may override your user settings," the Alert Ready website states.

The following are examples of emergency situations that could trigger alerts:

  • urban fire: an urban fire threatens multiple residential and/or commercial properties
  • industrial fire: a large fire in an industrial building or complex that poses a threat to human health
  • wildfire: a wildfire involves natural combustibles, such as grass, brush and trees
  • forest fire: a forest fire is a wildfire or prescribed fire that is burning in forested areas, grass or alpine/tundra vegetation and poses a threat to human safety
  • tornado: a tornado is a vortex of a violently rotating winds, often forming a funnel-shaped cloud that is capable of damaging property and injuring people
  • flash flood: often occurring from river ice jams and excessive unexpected rainfall, a flash flood is the sudden onset of water causing immediate flooding. This event presents a unique danger to life and safety as there is little or no warning that this event will occur
  • earthquake: an earthquake is a sudden release of energy in the Earth’s crust that creates seismic waves that can cause substantial damage, especially in urban environments
  • hurricane: a hurricane is a violent storm comprised of intense winds and, heavy rain, potentially causing a storm surge, floods, coastal erosion or landslides
  • biological: a potentially dangerous and poisonous substance that is usually very unstable and can be easily transferred between living organisms
  • chemical: a chemical substance that, if misused or released, could result in serious injury or death
  • radiological: with sufficient concentration, a radiological substance
  • drinking water contamination: when water quality is negatively affected and a boil-water advisory may be raised, cautioning use by the public
  • explosive: a potentially dangerous substance or device that may explode
  • air quality: a decrease in air quality is caused by an elevated particulate count in the atmosphere that can negatively affect visibility or the health of individuals
  • falling object: natural or human-made materials at risk of falling, which may threaten people or property
  • terrorist threat: use of violence or threats of violence by individuals or groups against civilians or infrastructure
  • civil emergency: a civil emergency occurs when humans cause a disruption of services or require varying levels of support, law enforcement or attention
  • animal danger: when a wild or domesticated animal poses a threat to human life or property
  • amber alert: an amber alert is issued by police services when a child has been abducted and it is believed that his/her life is in grave danger. An amber alert provides the public with immediate and up-to-date information about the abduction and solicits the public’s help in the safe and swift return of the child
  • 911 service: a 911 service alert happens when there is a disruption or outage of telecommunication services between the public and emergency responders
  • test message: a test message may be issued for either public awareness or technical testing purposes

Can you opt out of receiving these alerts?

The short answer is no.

"Emergency alerts received on your compatible wireless device are relevant to you and require immediate attention," Alert Ready says.

"Government regulations mandate that all compatible wireless devices receive all relevant alerts. Unlike radio and television broadcasting, which often has broad areas of coverage; wireless public alerting is geo-targeted and can be very specific to a limited area of coverage. As a result, if an emergency alert reaches your wireless device, you are located in an area where there is an imminent danger."

To receive emergency alerts, wireless devices must be:

  • an LTE-device like a smartphone (LTE is commonly referred to as '4G LTE')
  • wireless public alerting (WPA)-compatible
  • connected to an LTE cellular network at the time the emergency alert is issued

To check your phone's compatibility with the new alert system, please click here.

David Helwig

About the Author: David Helwig

David Helwig's journalism career spans seven decades beginning in the 1960s. His work has been recognized with national and international awards.
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