Not something supported by the OS. For example, if there is internet connection, then you can send a notification with your location and other device running your app, will receive the notification if they are near. This requires a complete solution. Not something that will "just work".
"The British government first tested a nationwide emergency alert system for mobile phones on April 23, 2023. The test message was sent to millions of mobile phones across the UK at 3:00 PM BST as part of a system designed to warn the public about life-threatening emergencies, such as extreme weather events or terrorist attacks."
Needless to say it was (in iteself) a disaster. A salutary lesson in what happens when governments actually do things.
“Cell Broadcast Service”
CBS is being used for the Public Warning System and can transmit messages through independent channels, which means regardless of network congestion, users can still receive messages within a few seconds as long as the cell phone is within the coverage area.
This should only be done by the government.
This line of thought brought me to mind the itag functionality...
Itags "broadcast" some kind of "I'm here" to nearby devices... and the device can be found by its unique identifier.
Can't something within the same guidelines be done using phones and BLE?
Much like the beacon snow skiers use in case of avalanche for easy find?
Edit: I just remembered, this "feature" already exists, and allow for quick share with devices within reach, even "unknown " ones... so it would be possible for devices to use a swarm like behaviour trying to get a message to a "queen" app.
Much like the seven degree theory!
Thailand struck an earthquake at 13.20 local time, but the government warned at 18.00 local time. (Myanmar occured11.00 a.m.) Some people recommend notifications via TV. But in my opinion, before the host dressed up for the broadcast, I thought it was too late, so I asked my friends in the group what your country is how to.
We are an earthquake-prone area.
We use Cell Broadcast Service (CBS) to send alerts from the government.
CBS is being used for the Public Warning System and can transmit messages through independent channels, which means regardless of network congestion, users can still receive messages within a few seconds as long as the cell phone is within the coverage area.
Sometimes you receive an alert seconds before an earthquake reaches your area.
In addition to using mobile phones, we also sent out alerts via television.
Yes, Sir. One of university team can do by using google chat, but I don't know how to do.It's more useful for world human. In my idea, it should can waring 5 languages besides of local country's. Currently, more Israelis are living in Thailand, but the area there is at risk of earthquakes because it has already happened, so there should be Hebrew as well.
In my country, the line app is popular for communication, and the line app has a line notify system, which can add up to 5,000 members. If you divide the group of people into regions and subdivide them into city levels, I think it should be possible to spread the message evenly across the whole country.
The best way to go is by involving the telecom companies (AIS, True, DTAC, ...).
A governmental institute should instruct these companies to send an emergency broadcast to all their customers (as it was explained above).
And then of course time is of the essence. The broadcast should be send as soon as possible and not hours later.
I'm sure you know some people who received a message from AIS about a possible After Shock around 7 pm., right?
So there was some initiative but not in time...