In iOS 6, Apple added support for Wireless Emergency Alerts (WEA), a system in the US that a few agencies can use to deliver things like emergency weather notifications and amber alerts. However, while iOS supports the feature, not all carriers have enabled it.
On devices that support this system, which FEMA turned on in April 2012, these alerts will appear like text messages but will not quite operate as such. In iOS 6, they appear as Push Notifications on the lock screen and at the top of Notification Center. Users are not charged for receiving these alerts, regardless of device, wireless provider, or service plan. All devices that support these alerts have them enabled by default.
WEAs get priority over other network communications and, due to their nature, are also location-aware. From the CTIA’s WEA overview:
While these alerts will appear on a person’s mobile device similar to a text message, Wireless Emergency Alerts are not text messages. Instead, Wireless Emergency Alerts use a different kind of technology to ensure they are delivered immediately and are not subjected to potential congestion (or delays) on wireless networks.
In addition, Wireless Emergency Alerts are a point-to-multipoint system, which means alert messages will be sent to those within a targeted area, unlike text messages which are not location aware. For example, if a person with a WEA-capable device from Washington, D.C. happened to be in southern California when an earthquake occurred in that area, they would receive an “Imminent Threat Alert” on their device.
As you can see in my screenshot, I received one of these alerts over the summer while using the iOS 6 developer betas. It was pretty handy. You can view and toggle the WEA options on an iPhone by scrolling to the very bottom of Settings > Notifications. I don’t recommend disabling them.
While USA Today says “carriers serving almost 97 percent of US subscribers have agreed to participate,” I’ve seen comments from some AT&T users that they do not yet see these settings after upgrading. Sprint does have them (hat tip John Morrison), so I don’t know if that means AT&T needs to enable something on its end or if an iOS 6 point upgrade is needed to flip the switch.
I also don’t know much about whether WEA-like systems are being built outside the US and what smartphone support is like. Anyone care to enlighten the class?