Hello, I'm currently working on an SOS app and I'd like to know if it's possible to send an alert to all phones with the app installed but without using the internet connection or SMS/MMS. I think Bluetooth wouldn't work because it operates over too short a range. Ideally, between 500 and 1000 meters would be ideal.
Thanks,
Nico
All devices on the same local wifi network ?
you might want to try
Taifun
No, I want it to be able to happen anywhere, with anyone who has the app.
I thought about using this extension that I have used in the past but I doubt its ability to go beyond 500 meters.
Indeed, I looked on Wikipedia and direct wifi cannot exceed 140 meters outdoors and 30 meters indoors.
Wifi Direct / Wifi Aware are your best bets
Just to be sure for the application design, do the addresses used by the extension stay the same (like the MAC address) or change often (like the IP address)?
What addresses? Because Android does not let you directly query your own device's MAC Address which is a unique identifier. Plus many modern smartphones practice what is called as dynamic MAC, where they keep changing their MAC addresses periodically.
So what are the addresses returned when devices are found?