MMS (Multimedia Message Service), namely multimedia information service, is one of the highest standards for SMS technology development.Its biggest feature is that it can support multimedia functions. With the help of high-speed transmission technology EDGE (Enhanced Data rates for GSM Evolution) and GPRS, it can transmit video clips, pictures, sounds and text using WAP as the carrier. It can not only transmit multimedia between mobile phones, but also between mobile phones and computers.
In the second generation mobile communication service, text basedShort message serviceIt is widely recognized by users[1]。During the evolution of mobile communication technology to 2.5 and 3 generations, people want to introduce pictures, sounds and animations into information services. Therefore, based on short message service, multimedia information service service is designed[2]。The capacity of multimedia information is determined by the operator. Generally speaking, the average message capacity is 30000 bytes, up to 100000 bytes;The built-in media editor of the mobile phone with MMS function can write multimedia messages. If the previous built-in or externalcamera, users can also create and transmit PowerPoint formatted messages or electronic postcards.In China, multimedia information is commonly known asMMS。
System structure
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Generally speaking, the multimedia information service system includes the following network elements: MMS terminal, MMSCMMS User Database , external application server, value-added application server and non MMS terminal support application system.In addition, in order to provide multimedia messaging services with the multimedia messaging platform, it needs the support of WAP gateway, GSM/GPRS network resources and other devicesbilling system 、Network managementSystem interconnection.
MMS Terminal/MMS User Agent
MMS terminal provides multimedia message service through MMS user agent.MMS user agent is an application on multimedia message terminal, which provides users with functions such as browsing, editing, processing multimedia messages, and operations such as sending, receiving, and deleting multimedia messages.MMS user agent supports MIME. Multimedia messages can contain textimage, sound, etc.
MMS Relay Server/Multimedia Message Service Center
(MMSC) MMSC is the core of the whole multimedia message system, which stores and processes multimedia messages, including message input/outputAddress resolution, notice, report, etc.At the same time, it is responsible for the transfer of multimedia messages between different MMSCs.MMSC also generates CDR bills for billing.In addition, MMSC needs many connections to other networks and carries out various value-added services.The MMS trunk is the IP interface of the system.The system is connected to various networks through it and supports multiple protocols.
MMS Redirector
Under the condition that the URL address of the MMSC is unified throughout the network, the device is responsible for the route query of the user's home MMSC.It also determines the MMSC of the sender user according to the MSISDN number of the HTTP packet, and returns a redirect message to the WAP gateway to forward the HTTP request to the MMSC.
MMS User Database
It is used to store user service information, service type, personalized service information, etc.The database in the target network is mobiledata service As a part of the management platform, it can be integrated into the MMSC system at the initial stage of network construction.
External application server
The multimedia message center supports interfaces with a variety of external applications, and can extend some existing message systems to multimedia message applications.These message applications include: E-mail system, VoiceMail system, etc.
MMS value-added application platform
It is a value-added application platform based on multimedia message platform, and MMSC should provide an open platform.Standard API interface, supporting value-added application development.
WAP gateway
The WAP gateway technically follows the MMS specification defined by the WAP forum to support multimedia messaging services.Establish MMS through WAP gatewayuser agent Data access channel with MMS relay server to support sending, receiving, notification and other operations of multimedia information.For MMSuser agent The connection with the WAP gateway is implemented by WAPStackwireless networkBearing on the platform.For MMS applications, wireless session protocol (WSP) is used to transfer data.
billing system
MMSC is the billing data collection point for MMS services. It generates business service usage records (CDRs) based on traffic and duration and transmits them to the billing system for billing.The billing system function should be in mobiledata service It can be realized in BOSS before the completion of mobile data service management platform.
Take the system sending messages to mobile phones as an example to analyze the process of multimedia information service.In the process analysis, the part related to wireless access is omitted, and only the relevant part of is emphasized.
1. When a multimedia message is sent to a user, the message is encoded using the WSP protocol of WAP.adoptwireless networkTo the WAP gateway.
2.WAPgatewayCommunicate with MMS Relay via HTTP protocol, and transfer the file content to MMS Relay.
3. MMS Relay sends files to the MMS-C server.The content of multimedia information in the server will be converted into MIME format.And stored in the MMS Message Store.
4. The server performs data analysis to obtain routing information, user terminal information, etc.Information in user database will be called during analysis.The system will judge whether the user's terminal can support MMS, and conduct different processing according to the bearing capacity of the user's terminal (such as display resolution, terminal capacity, etc.).For example, when the user terminal does not support MMS, the system will remove the multimedia information from the multimedia information and only send the text part of the information to the user as a short message.
5. After confirming the processing method, the system routes through the called user's MSIS-DN number.MMS Relay will communicate with the external network through the WAP gateway.The information is always saved in the message until the called user is confirmed to have received itstorageMedium.The operator can set the length of time for saving through software.
6. The system server generates billing information and transmits it to the billing center.
basic function
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Multimedia information service system generally has the following functions.
1. Sending and receiving multimedia messages.After the mobile terminal synthesizes multimedia messages, it can send multimedia messages to all legitimate users in the network.MMSC stores and processes multimedia messages, and is responsible for the transmission of multimedia messages between different MMSCs.At the same time, the receiving user can receive multimedia messages from MMSC.
2. Provide support for non MMS terminals.This is a non multimedia messageSupport systemTo complete.Taking the process of non MMS terminal receiving multimedia messages as an example, after receiving SMS notification, non MMS terminal users can access multimedia messages through other means, such as E-mail, WAP, www browsing, etc.
3. In terms of network bearer mode, CSD and GPRS based bearer mode is supported at this stage, and 3G bearer mode will be supported in the future.
4. Multimedia message service supports point-to-point service and point-to-point service.Point to point multimedia message service refers to that the sender and receiver are the same terminal or application system;Point to multipoint multimedia message service refers to that the receiver is multiple terminal addresses.Multiple receiving terminal addresses can be specified during a multimedia message transmission.
5. Support for MMS value-added applications.In addition to supporting some existing application systems (such as E-mail system), the multimedia messaging system should also provide open and standard API interfaces to support value-added application development.
Business realization mode
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At present, multimedia messaging services are carried out in three ways:
The first is that both the sender and receiver use mobile phones with MMS function to directly transmit.
The second is that the sender has a mobile phone with MMS function, while the receiver is an ordinary mobile phone.At this time, the receiver can apply for an email address with its mobile phone number as the mailbox name on the mobile dream website. When the sender sends an MMS, the receiver's mobile phone will receive a SMS notification from the mobile dream MMS to the mailbox.The receiver can log in to the mailbox to check MMS.
The third is that the sender using an ordinary mobile phone can send MMS directly to the receiver using an MMS mobile phone on the Internet.
Comparison with SMS
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MMS and SMS both send messages in the same way: both store and forward services, that is, messages are not delivered directly to users.It is sent to the message center first, and then forwarded to users through the message center.However, there are also great differences between MMS and SMS:
1. SMS, as a carrier, can carry out various applications, such as mail arrival notification, weather forecast, news, ringtone picture download, lottery, games, securities, etc.MMS, as an application carrier platform, can provide more abundant applications in addition to the above applications.
2. In terms of bearer mode, SMS is a signaling channel using GSM.Due to the limited transmission capacity of signaling channels, it is impossible for SMS to transmitbig dataTherefore, SMS based applications cannot be carried out arbitrarily.It must be a small amount of data application.However, MMS is based on WAP services and uses data channels. Its transmission capacity can reach 9.6 kbit/s in CSD mode, 184 kbit/s in GPRS mode, and 2 Mbit/s in 3G mode, which provides great convenience for application development.Users can send and receive data as they want, instead of beingbandwidthLimitations of.
3. In terms of content capability, SMS can only send and receive text messages, and each message can only carry 140 messages at mostbyteOr 70 Chinese characters.Although EMS (Enhanced Message Service) can support graphics, sound and animation information, the format of these data is too simple, and users' experience of EMS is far less than that of the traditional Internet.And because the size of each SMS message remains the same.To transmit more than 140byteEMS messages must be split into multiple SMS messages and then combined on the mobile phone.More importantly, although EMS is also the standard of 3GPP, it is not supported by all mainstream mobile phone manufacturers. There must be obstacles in the promotion. MMS can support rich data formats, including major graphicsimageThe sound and animation formats are standard. Users feel the same as the traditional Internet. In the futurebandwidthIf allowed, it can also supportStreaming Media, greatly improving the richness and expressiveness of message content.Moreover, the message size of MMS has exceeded 140byteFrom tens of K bytes to hundreds of K bytes, users can almost completely express their thoughts in one message without being affected by the amount of information.
4. MMS is different from SMS in network structure.MMS adopts the processing flow of WAP events. The receiver takes the initiative to get information from the MMSC, which is the same as the browsing or downloading method of WAP.
Development prospect
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On October 9, 2002, China Mobile held theMMSAt the commercial press conference, it was announced that the MMS service had been officially commercialized on October 1, 2002, and the multimedia era of mobile communication was coming.
However, what aspects do users care most about?A few days ago, China Mobile Communications website conducted a survey on the Internet of "What factors do you care most about when choosing MMS services". The top three factors are the price of mobile phones (32%), the price of short messages (29%) and ease of operation (14%).
The price of MMS mobile terminals seriously affects users' acceptance.If with the development of MMS business, mobile phone manufacturers cannot produce mobile phones with low prices and novel styles, it will seriously hinder the promotion of MMS.It is said that at present, China Mobile is negotiating with the terminal manufacturer. It is prepared to bundle the MMS service and mobile phones to users while launching the MMS service, and reduce the price of mobile phones to promote the service.In addition, when people really like and get used to MMS services, the role of price factors will be relatively reduced.
at presentMMSThe service adopts the original charging mode of short messages, with a price of 0.90 yuan per message. At the beginning of the service, the preferential measure of "sending two messages and sending one message free" is implemented.The actual price is 0.60 yuan/piece.According to statistics, the number of short messages sent in China in 2001 was 15.6 billion, 80% of which were text messages sent from mobile phones to mobile phones, and 20% of which were text messages sent through Mobile Dream and SP websites.However, a little calculation shows that the price of 20% of SMS traffic is equal to or even more than the price of the other 80% of pure text SMS traffic (the price of pictures varies from 0.5-2 yuan/piece, and the price of ringtones varies from 0.5-4 yuan/piece, which is 5-40 times the price of pure text SMS messages of 0.1 yuan/piece).NowMMSThe price is only 9 times that of SMS, which is acceptable to most users.
Another noteworthy problem is that the details of MMS value-added business development are not clear at present, such as how users order business, cancel business, etc., the interface with value-added business is not determined, and the standard is being formulated, which will lead to the slow development of MMS value-added business in the initial stage.
Although MMS has many advantages, it will not replace SMS immediately and will coexist with SMS for a period of time.With the gradual withdrawal of SMS business market, MMS will become the main theme of SMS market.(Modern Communication)
