Cannot send MMS when cellular data is not enabled

[Alfonso Sanchez-Beato]

It is not possible to send an MMS in case cellular data is disabled. This might look as an invalid bug because MMS needs cellular data to work, but it is not that obvious. For instance, in Android you can send/receive an MMS even when you have set cellular data to off.

The rationale behind this is that MMS and internet traffic are tariffed differently. You do not pay for receiving an MMS, just when you send, which is your decision, so you can always control how much money do you spend on MMS and you can have it enabled always (same as SMS). However, all internet data you send or recieve is tariffied. Therefore, Android in fact interprets the cellular data setting as *internet data* on or off. We should probably do the same.

An interesting side case is roaming. When MMS started there were many complains about being abroad, receiving an MMS and then get a expensive bill showing you connected to data while abroad. So we should consider data roaming off as cellular data off for both internet and MMS data.

[Tony Espy (awe)]

A few comments/questions:

 - what does Android do, does it temporarily enable data for the sole purpose of uploading a MMS payload?

 - what about receiving, does Android allow receiving a MMS when mobile data is disabled?

 - iOS8 doesn't allow a MMS message to be sent if mobile data is disabled. I didn't check the receive case, however note the user experience is pretty much the same as ours, a failure indication is shown in Messages, but no real explanation given.

 - it might be a good short term enhancement to add a more meaningful error popup to the messaging app when mobile data is disabled, or better yet disallow the user to tap the camera icon in this state.

 - I'm not sure I agree with the statement that received MMS messages are free, I think this is dependent on the carrier, and is one of the reasons some phones have the ability to defer downloads of MMS content.

For now, I've confirmed and changed the importance to Wishlist.

[Chondoud (nicolas-eubriet)]

Hi
I confirm the bug on my BQ Aquaris E4.5 even after OTA6.
I don't have knowledge in communication system or mobile phone dev. but as a user and travelling to foreign country, I disconnect the data in roaming but I was always able to send MMS in roamming this my Android or iPhone (long time ago).
Don't hesitate to ask if you need any test and thanks for any help