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Samsung factory unlocked S9/S9+ will now have Verizon Wi-Fi Calling

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CrazyApe18

Senior Member
Jul 6, 2018
615
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I'm reposting this in a new thread for better visibility. I hope this is useful information for people to understand the way the unlocked/U1 models work with various carriers, and how new carrier-specific features could be implemented in the future.

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Wi-Fi Calling on Verizon with U1 is enabled by a new APK which has been added.

com.verizon.loginengine.unbranded

It's displayed as Carrier Login Engine. It appears to have a similar function to the UI-less "My Verizon Services " (not to be confused with the My Verizon app) which is baked into U firmware for carrier devices. Once Carrier Login Engine has been given permissions (which you'll be asked to do when you attempt to enable Wi-Fi Calling), the usual Wi-Fi Calling APK will be invoked.

Samsung also changed the permissions on the Wi-Fi Calling APK to allow the Verizon activity/intent to proceed. In prior U1 builds, a shortcut maker type app could invoke other activities on the Wi-Fi Calling APK and you could see the dialogs for certain carrier's Wi-Fi Calling setup screens, but never Verizon's (although it was clearly visible in the intent list).

I don't know if this will prove useful to anyone, but this is how they did it.

TL;DR, the total changes to U1 to make this work are:

- Add Carrier Login Engine to U1 firmware (see above for the full package name)
- Change permissions on the existing Wi-Fi Calling APK to permit the Verizon activity to be executed by non-root user

Remaining question: What does Carrier Login Engine do? Why is it needed? Well, a differently named APK asks for permission with the Sprint SIM profile when attempting to enable Wi-Fi Calling on the U1 firmware. So it looks like they've got the same thing. Verizon has simply added theirs to the newest build.