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Cell Phone Data Usage by Computer

I'm a participant level 3
I'm a participant level 3

Can anyone tell me how it is that my computer uses my cell phone data allowance?


I have Rogers Wi-fi in my house.

I have a Samsung Galaxy Grand Prime, with 500 mg data from Fido.


My cell phone is paired (bluetooth) with my computer.  They are not tethered.


I always use Wi-fi on my computer, and always at home.

I use Wi-fi on my phone unless it's not available.  I usually turn on the Data switch only when I want to use it.


In one day, I used up my entire Data allowance despite the fact that I hadn't used my phone for data at all.

I was told, by Fido, that the allowance must have been used by my computer use.


It is true that I had neglected to turn off Data on my phone, which I usually do.

Also, although this might not be relevant, the Smart Network Switch on my phone was on.


The thing I don't understand is the mechanics of the connection between my computer and my phone to allow the computer to use the phone's Data plan.  If someone can explain this to me, I'd be delighted.



Hello @vivsim,


Welcome to the community!


The Smart network switch allows you to switch automatically from Wi-Fi to Mobile data if the Wi-Fi connection is unstable.


I would safely say that having the smart network switch on is the reason why you consumed all your data.


Because you are using an Android phone you can set a data limit so when you hit that limit the phone will turn off your mobile data. You can get more info and how to set that up here.

I'm a participant level 3
I'm a participant level 3

Thanks for your reply, Kapable-K. 


I'm not wondering about the data usage on the phone itself, though.


Rather, I want to know how it is that my computer uses the phone's data.


Other than Bluetooth pairing, my phone and my computer aren't connected, so I don't understand how this happens.


@vivsim if you did not setup a tether connection and just have your phone simply paired to your computer via bluetooth its not possible for your computer to use your phones data.


I think the agent just didn't know enough and give you wrong information.

I'm a participant level 3
I'm a participant level 3

Thanks again, Kapable-K


That's what I thought, but had to bow to those who appeared to know.  I actually spoke to two people at Fido and they told me the same thing.


I agree with you - they must be wrong.


Given that that is the case, I'm left wondering how I managed to use almost 400 mb of data in one day when I didn't use my phone, except for a couple of short local phone calls.  Data was turned on, and so was the Smart Switch, but I had no open applications (except whatever might have been running in the background).  I've double-checked that tethering isn't on.  This has never happened before, and I'm really perplexed.  I will be monitoring my usage every day from now on to, hopefully, find some pattern.


Thankfully, Fido waived the fee for going over my limit, an actually gave me extra for free to get me through the rest of the month.


If anything occurs to you, I'd love to hear it.

I'm a participant level 3
I'm a participant level 3

Since my last posting, I learned that my data limit had been exceeded by 1.1 gb (it seems that Fido's records are four hours old), so I've been back on the phone with Fido trying to sort this out.


Fido first told me that my computer was probably using my phone’s data connection. This turned out to be nonsense as my phone and computer aren’t tethered, although they are paired via Bluetooth.


They then told me that phones go to sleep at night and, if they’re awakened by overnight software and firmware updates, it’s possible that Wi-fi will be dropped and Data used.   They were able to determine that my Data usage did occur overnight and, on that night, I had forgotten to turn off Data as I usually do. So, it seems there’s some truth to this, although I wonder what kind of update would have used 1.6 gb.


Fido was very accommodating, but it’s taken hours to sort this out and I don’t ever want to go through it again, so I’ve decided to do a couple of things to avoid possible overnight Data usage, and to otherwise contain costs:


  • Turn on Data only when I want to use it or, at least, turn it off at the end of each day
  • Turn off the Smart Network Switch (Android) or the Wi-Fi Assist (i-phones). If you’re using Wi-fi on your phone, these switches will switch you to Data, unseen by you, if the Wi-fi is weaker than Data.


If this of concern to you:


  • To turn off the Smart Network Switch (not all phones have it): Settings, Wi-fi, click on your menu icon, scroll to Smart Network Switch
  • To turn off Wi-fi Assist: Settings, Cellular, scroll to Wi-Fi Assist

I hope this will be the end of this saga, although I'm a bit sceptical.  I'll be monitoring my usage daily for the next month or so.  I'll post here if there's anything more to say.

The pairing would definitely not use data if tethering is set at off. Sorry for the misunderstanding on that. 


If you need further help with that, don't hesitate to reach out, we're here to help Smiley