February 22, 2016

Stopping a Smartphone from Automatically Turning On Data

A couple weeks ago, I bought a new Samsung Galaxy Core Prime smartphone from T-Mobile because my old dumb cellphone decided to suddenly stop working. (Actually, there's reason to believe it was obsoleted without warning by Tracfone through a change in their network, but that's another story.) Like any normal guy in the modern world, I sat down as soon as I got home to play with my new device. I particularly wanted to make sure I was in control of when it used data.

It didn't take long to discover that the phone would turn on its mobile data connection itself, even after the appropriate switch in the settings had been set to turn it off. That, in my opinion, is just unacceptable.

The Core Prime phones aren't top-of-the-line Galaxy phones, of course. They're fine for people who need a phone rather than an entertainment device or a portable office, though, and shouldn't suck up data on their own accord just because they're not high-end devices.

For reasons explained later, I put off the ideas of contacting T-Mobile for help and of trying to find if some preinstalled app was responsible for the problem. Instead, after poking at settings for a while with no joy, I turned to the web.

Searching brought up a variety of possible ideas for cause and/or solution, including...
  • Set "Restrict background data" in the MORE menu within the Data Usage settings.
  • Disable automatic date and time update.
  • There is an unnecessary or "virus-type" APN installed in your smartphone.
  • There is an App called VPN *a virus that causes this.
  • Turn on Airplane Mode (which, of course, turns off the phone along with the data).
  • Choose a Network mode setting in Mobile Networks that doesn't include "auto connect".
Excluding the "virus" ideas, which I chose to disregard (they're brand new phones, after all), none of the above resolved the problem.

About contacting T-Mobile for help, I figured that most people would contact their service provider with problems connecting to the internet rather than the other way around, so it was unlikely they would have any practical advice. This opinion was bolstered by a forum post from someone having a similar problem with a Galaxy S4 on AT&T's network. The post said "We tried calling AT&T and they said that its what the phone is supposed to do and they can't disable it. When asked if we could, they said 'I don't know.'" (http://forums.androidcentral.com/t-mobile-samsung-galaxy-s4/314192-how-completely-disable-mobile-data-being-turned.html#post3066090)
Finally, I set out to determine if some preinstalled app was responsible. I was avoiding this because it meant having to determine *which* of the apps was a problem. That meant having to check the permissions of each app in the Application Manager's "All" list to...
  1. determine which apps had permission to turn mobile data on and off,
  2. determine which of those could be disabled, and
  3. determine which of those run at startup.
Then it'd be necessary to determine which of those constituted the offending app(s) by trial-and-error.

The results of 1 thru 3 were...
  1. 105 apps,
  2. 24 apps, and
  3. 22 apps.
The names of the final 22 apps follow. Do any look particularly suspect to you?
  • com.tmobile.pr.adapt
  • Contacts
  • Contacts Storage
  • demo stub
  • Download manager
  • Galaxy Apps
  • Google Account Manager
  • Google Backup Transport
  • Google Contacts Sync
  • Google Play store
  • Google Services Framework
  • Hangouts
  • LogsProvider
  • Lookout
  • Media Storage
  • Messages
  • Samsung Billing
  • Setup Wizard
  • T-Mobile Name ID
  • User Dictionary
  • Visual Voicemail
  • YouTube
Hmmm... Maybe com.tmobile.pr.adapt?

Following this suspicion, I disabled com.tmobile.pr.adapt. That did it! There've been no unauthorized data connections since, everything works as expected with the mobile data off, and everything works just fine if I choose to turn on the mobile data. So... Problem solved!

Hopefully this will save some T-Mobile users with Samsung Galaxy phones a bit of time and frustration, and give other users an idea of what to look for if their phones are insistant on wasting data.