Mobile data..

it will depend on your plan. for me i have unlimited texting and does not affect my data usage. so its never been a worry for me.

 

SMS don't use mobile data (at least not for GSM networks - I don't know how they work for CDMA). MMS do, but most networks I know count them separately.

"Background data" is still data, so no different from foreground data usage.

 

Not sure what you mean by "roll over".

I get 20GB a month mobile data on my current China Unicom package. Some apps can use that, as well me browsing websites. I have a separate allowance for both SMS and MMS sent, that doesn't come out of my data usage, as well as unlimited domestic calls, and so many minutes of international calls a month.

 

Hmm, a good point: to me "roll over" means "unused allowance can be carried over to the next month", which I did once upon a time have but it was a very long time ago. Most tariffs just give you a new allowance each month.

That said, as my calls and SMS are unlimited, I don't use MMS, and my data allowance is a good order of magnitude more than I use (though it gives us a float in case we suffer a broadband outage), rolling over isn't actually a priority for me either.

 

So it's the same meaning - cool.

Where I am in the UK such packages are rare now. In the early days of mobile phones taking off there was a lot more variety in the packages as the carriers competed to grow their customer bases. Now that everyone has there is less variety in the offerings, and I've not seen rolling over of allowances for a while.

(By "less variety" I not only mean that things like roll-over have disappeared, but all tariffs are basically very large or unlimited call/SMS allowances, varying data allowance, and out of bundle costs that are much higher than they used to be, but with most tariffs having large enough allowances that for most people this doesn't matter anyway. They basically market on data allowance and monthly cost, and that's it).