Using tracking devices have to be upgraded to 3g services. Or you can use a twilight network, which may or may not work, and will eventually be taken down. This royally sucks, because I had just finished an Arduino tracker, using a grps and a gps shield, which would have been great for tracking a work vehicle. I had it all set up, and ready to go, and then one day it stopped working. I even changed my sims ‘cause I thought it was the sim cards. And it was, in a way.

Nowadays, it’s easy to find gprs shields, but they all use the 2g networks, which are now in the sunset mode, and are entering the end of life. So if you’re using an Arduino tracker or custom hardware and it suddenly stops working, it’s probably your gprs device. I’m still waiting for a 3g version, but the device I used is pretty much SOL. Which again, was a bummer ‘cause I just got around to that project. Welp, looks like I have to start over.