For UK-telco supplied Android mobiles - e.g. Samsung S4 from EE, vodafone, or O2 - how do OTA updates get triggered ?
Would the OS poll for, and retrieve, updates via any old IP network ? Or does it the phone need the operator's SIM in it, and is this tied to identifying the availability of new updates and attempting to download them?
Reason for asking - looking at deploying a few phones for company use and want to know if they can be received from the Telco, unboxed, joined to WiFi and told to search for and apply updates to whatever Android image is on there. i.e. without supplying a SIM, a Google account, Samsung account etc etc.
Its been a while since I've had a 'stock' phone so I can't remember how this worked, and of course it may vary.
Thanks in advance !