Is it possible to send MMS instead of SMS to a short number?

Question

Android

For example, to confirm the payment "Send 1 in reply"
For the thesis (IP-networks and GSM-telephony) I am writing my SMS/MMS client.
There was an idea to take the source code of the system application and add new features, but the teacher decided that I should think over the application myself, and not "act like an Indian" or "narrow-eyed", "your diploma is not on this topic."
That's why I'm writing from scratch.
I'm working with API Level 21, where sending SMS and MMS is now equally easy, there are no problems with this.
But you need to study the problems of reliability and in an explanatory note describe everything, what and why.
The application will support emoticons, emoji and more. When they are added, the message is automatically converted to MMS and then sent by MMS.
But let's imagine that when sending such a message, the user accidentally clicked on an emoticon. Of course, he removed it and the text of the message again contains only "1", but the message itself was not converted back and sent as an MMS.
What will happen?
Will such a confirmation roll?
Will money be written off for the message itself, if, for example, the provider's algorithm is a little more complicated, and this is not a confirmation of payment, but just a message that differs from the usual one in that it comes to a short number and is processed by automation there?
Does this automation work differently for SMS and MMS?

Answer 1

What numbers do you need to send messages to - subscriber numbers (ordinary people), or short ones?
If short, then I would proceed from the fact that short SMS-numbers via MMS are not available - and vice versa.
Therefore, I suggest that in the application, if possible, explicitly convert the message to SMS format.
Although both SMS and MMS messages will fly from subscriber to subscriber in the same way.
A bit of theory for the diploma to understand why ;)
This difference is due to the different ways of sending SMS and MMS messages:
- SMS messages, as invented earlier, are transmitted via _mobile signaling_ channels to a node called SMSC. The historically adopted protocol for connecting external SMS handlers to the SMSC is called SMPP.
- MMS messages, invented later, are transmitted over a packet channel (we can say that over the Internet - although there are, there are nuances) to a node called MMSC. To connect external MMS message handlers, the 3GPP committee gave birth to an interface specification called MM7 - this is SOAP.
Based on personal experience, I would expect that the SMPP client processing SMS messages on short numbers and the web service processing MMS messages are two DIFFERENT programs that have no idea about each other.
Now about the withdrawal of money.
Here, again, short numbers stand apart.
Writing off money for messages _from subscriber to subscriber_ by the piece in our time, / as a rule /, is handled by the online billing system - OCS. / As a rule /, OCS connects with both SMSC and MMSC (via MM9 interface), and how much it calculates them is written in the description of the tariff plan on which the subscriber sits.
But in the case of short numbers, the cost of the message will most likely be determined by the handler: an SMPP client for SMS and a web service for MMS. This is due to the fact that the _content_ of the message is not transmitted via standard billing interfaces - and it can just affect its cost ("send 1 to buy 1 GB of Internet or 2 to buy 10 GB").
And here we, again, find that the short number can be accessed, for example, only via SMS.