The user in specification terminology) is software on the subscriber side, which allows you to receive, send, view and process multimedia content on the mobile terminal.
For a communication exchange environment (it is difficult to find a Russian analogue English terminology exchange), the service user who sends and generates multimedia content is called the originator, while the service user who receives the sent content is called the recipient.
In order to be able to send a message to a subscriber, it is necessary to know its current location (for example, service), so the MMSC is also connected to .
The MMSC is also responsible for temporary storage (cache mode) or permanent storage of messages (providing the MMBox service for subscribers).
Let's take a closer look at that part, specifically the MMSC (see figure below), which is associated with storing messages.
In order to determine options for storing multimedia messages on the MMSC side, it is necessary to take a more detailed look at the existing mechanisms for delivering these messages.
According to the specification, there is a so-called immediate and deferred sending of MMS messages, which is determined on the recipient's side. Sending a message immediately is similar to the mechanism of delivering a message to the recipient, i.e. The message is delivered immediately after it is sent, but in the event its content can reach a significant size and the recipient may not be able to process it (does not have enough memory to store the message). In addition, this mechanism opens up wide opportunities for spammers to deliver intrusive content to the recipient. To avoid such situations, the specification included the possibility of differentiated or deferred dispatch, the mechanism of which consists of two stages:
- MMSC temporarily stores (starting from version MMS 1.0) a message for the recipient in a temporary storage - Temporary Message Store and creates a kind of notification for the recipient, which indicates the characteristics of the message (size, type, etc.).
- MMSC informs the recipient that a certain message has arrived for him using a created notification, and the recipient himself “decides” whether he should accept the specified content immediately or a little later, based on his capabilities.
In the case of these two methods, the recipient has the right to use the following mechanisms in relation to the received message:
- Rejection of the message– reject receiving a message.
- Forward of the message– redirect message to remote Mailbox, or to the address of another recipient.
Starting from version 1.2, the user is given the opportunity to store communications in the so-called. Multimedia Message Boxes ( MMBox) – in the network storage (Permanent Message Store) on the MMSC side. With MMBox the user can:
- store sent/received multimedia messages;
- request messages from the repository;
- save messages that have been forwarded to other recipients;
- download/delete/view already saved messages;
- redirect messages from the storage to other users;
Actually, with the help of such mechanisms my multimedia messages that I transmit or receive on my mobile device can be stored.
Another quite interesting option for sending messages, in my opinion, is the so-called. reply payment, which allows the sender to pay for all replies to his sent message from the recipient(s), specifying several conditions that must be met by the recipient(s) in order to pay for the reply message. These conditions may be:
- response deadline – the sender of the message can indicate that the response message will not be paid if the response is sent after the specified deadline.
- response size – the message sender can set the maximum size of the response message; if the response is larger than the specified size, it can be delivered to the message sender, but will not be paid for by him.
But that's a completely different story...
A little helper:
HLR– Home Location Register
MS– Mobile Station
SGSN– Serving GPRS Support Node
SMS– Short Message Service
VAS– Value Added Services
WAP– Wireless Application Protocol
Articles and Lifehacks
MMS messages are a service that allows you to send different files, including photographs, pictures and animated images.
Sometimes situations arise when you need to edit received or sent media files, which is why the question arises, where are mms stored in android.
In general, all mms can be viewed in the “Messages” folder. But only viewing is available there, that is, it turns out that you will not be able to edit received files in this folder.
Where are received mms stored?
- If you receive an MMS message and your phone refuses to open the image, you can see it using the Internet. Most often, at the end of the message you can see the inscription “To read the message, follow this link.”
- Click on it and enjoy viewing the file.
- If your device supports the mms function and the settings are set correctly, then in most cases you will see the file sent to you when you open a message.
- All received MMS messages are saved in your phone at this address: /data/data/com.android.providers.telephony/app_parts.
- Each of them is saved in the PART_1228000671287 format, which has no extension. That is, it turns out that you won’t be able to open it just like that.
Where are files received from mms stored?
- When you open an image obtained this way, you can save or delete it. To do this, hold your finger on the message, and then select the item you need in the window that appears.
- By clicking the “Delete” button you permanently erase it from memory mobile device.
- If you click “Save”, then the picture will become available for opening at any time. You can find it in the “Download” folder, which is located in “My Files” in the main menu.
- Here you can rename the image, delete it, or send it via MMS message to another subscriber.
There are many apps that can easily backup messages or import saved copies back into your phone. But SMS notifications may contain important personal information, which I would not like to trust to programs from third party developer. So let's try to pull it out necessary files manually. To do this, you need to find out where SMS are stored on Android.
Access to SMS
Directory that contains the file with MMS and SMS:
/data/data/com.android.providers.telephony/databases/mmssms.db
The problem is that this file stored in the protected memory of the Android OS. Alas, but without availability root rights or ADB Shell, you will not get into this directory.
Export and import SMS manually
Having superuser rights, you can save SMS to a memory card using special Unix commands. To run these commands, you will need an Android terminal emulator and the BusyBox application. From the BusyBox commands provided, use the copy command.
Export:
$ cp /data/data/com.android.providers.telephony/ databases/mmssms.db /sdcard/
Import:
$ cp /sdcard/mmssms.db /data/data/com.android.providers.telephony/databases/mmssms.db
$ chown radio:radio /data/data/com.android.providers.telephony/ databases/mmssms.db
$ chmod 660 /data/data/com.android.providers.telephony/databases/mmssms.db
Space before databases/ not needed.
Any sqlite embedded relational database editor will help you open a file with the .db extension, for example