multimedia messaging service center (MMSC)
The MultimediaMessaging Service Center (MMSC) is the switching and management center for Multimedia Messaging Services(MMS). The MMS Center consists of two components: the MMSC Relay and the MMSC Server with database and memory. All multimedia messages transmitted to the Multimedia Message Service Center via GPRS, EDGE or UMTS are temporarily stored in the MMSC and forwarded to the receiving address.
If an MMS message cannot be delivered to the recipient, it will continue to be buffered in the Multimedia Message Service Center until the subscriber is reached and the multimedia message can be transmitted. When the subscriber has received the multimedia message, the receiving device sends a confirmation to the MMS center. If the recipient cannot be reached, the MMS cached in the MMS Center is deleted after a fixed time.
There are specified reference points or MMx interfaces, MM1 to MM10, between the Multimedia Messaging Service Center and the various provider services. Some of them have been specified by 3GPP.
MM1 is the multimedia interface between a mobile station with user agents and the MMSC. Through this interface, the subscriber sends an MMS to the MMS center, which forwards it to the receiver. The transmission protocol used for MM1 is the WAP protocol with the Password Authentication Protocol( PAP).
The interface MM2 is used for communication within the MMSC, namely between the MMSC relay and the MMSC server with the database.
MM3 specifies the reference point between the MMSC and the external servers for e-mail, fax, voice mail, streaming, short message service( SMS), unified messaging services( UMS), or other services.
Through MM4, the MMSC can communicate with other MMSCs and exchange multimedia messages with them. The two MMSCs communicating with each other are usually located in two different mobile networks.
MM5 is a reference point for other network elements such as for Home Location Register( HLR). Like MM1, the MM5 interface was specified by 3GPP.
MM6 is the interface for external databases, the MMS User Databases.
MM7 is the reference point for communication with a provider of multimedia value-added services. The messages transmitted via the MM7 interface are encoded in XML and are transmitted using HTTP. MM8 is used to communicate with billing systems, MM9 is used to connect to an online charging system, and MM10 is used for the messaging service control function (MSCF).
In addition to the MMx interfaces, the MMSC has a Standardized Transcoding Interface( STI) that connects the MMSC to a transcoding server. This transcodes the graphics format of the user agent(cell phone) into that of the receiving terminal.