I read the Wikipedia article but it's not totally clear on how Android updates are pushed to devices. This is what I understood but am not certain which is correct so please add details to approve or disapprove my statements.

Case A Phone has some service that periodically checks manufacturers servers (with some sort of polling) then if there is a new update it informs the user with a notification. User than clicks the notification and downloads and installs update from manufacturers server

Case B OS updates are just like ordinary software updates, there is a Google Cloud Messaging or similar broadcast receiver active on the phone and manufacturers just send message using this which shows user a notification. User than clicks the notification and downloads and installs update from manufacturers server

Case C Phone is notified about the updates by the mobile network (over-the-air provisioning (OTAP) like MMS and WAP settings) and than it shows a notification of the update. User than clicks the notification and downloads and installs update from his/hers mobile network provider

These all seem probable but consider these cases: What would happen if phone is not registered on network for a long time and internet is disabled (think of a tablet without internet access for example)? Why are phones with same version (international version) of firmware getting new updates at different times on different networks?

NOTE: I recently found out that CyanogenMod has OverTheAir updates in newer versions, how are they doing this, I doubt they have mobile network providers support?

  • I think part of your confusion is down to the fact that the correct answer is "all of the above and more". There is no one way that Android gets OTA updates, different manufacturers and different phone networks do it differently.
    – GAThrawn
    Mar 13, 2014 at 16:13
  • 2
    Cases A to C are valid options. In the remaining case, the devices simply would not receive OTA updates: though the name is "over the AIR", it still requires a network. Updates are not a kind of flu (though it sometimes looks like :)
    – Izzy
    Mar 13, 2014 at 16:18
  • Another reason why same updates on same handsets happen at different times is because most manufacturers/carriers release OTA updates in staged roll-outs, meaning that they notify subscribers in small batches over the course of a few days/weeks. They do this to avoid overloading their server when many people try downloading (usually sizable) update files simultaneously.
    – Chahk
    Mar 13, 2014 at 16:43

1 Answer 1


CyanogenMod ROM has a built-in Updater application which can periodically (or manually) check their servers for a new release of the ROM. Your current ROM version and date stamp are sent (in a completely anonymous way, no identifiable information is sent for privacy reasons) to their servers, and any new versions are returned. The user is then presented with a notification, and can choose to download the update (entire ROM actually) and automatically or manually flash it via Recovery.

About phone Update checker Frequency options

  • 1
    Thank you for response. This does explain that CyanogenMod uses Case A which I explained in the question but doesn't actually answer the question of how factory Firmware does this. Mar 13, 2014 at 14:48

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