Multimedia Messaging Service (MMS)

What is Multimedia Messaging (MMS)?

Multimedia Messaging Service (MMS) was first available commercially to mobile phone users in Norway. Launched in 2002, MMS is now a common and essential feature for many mobile devices. Each year, billions of MMS messages are sent between mobile phone users around the world. Also known as picture messaging, MMS is much more than simply about sending and receiving digital photographs. MMS also allows mobile phone subscribers to share unlimited text messages and graphics, as well as audio and video content.

About Multimedia Messaging Service

MMS is a store and forward messaging service between mobile devices. The service allows mobile phone users to send and receive messages with multimedia content to other subscribers. MMS messages are commonly sent on devices with built-in cameras, allowing users to instantly share digital photographs. In addition to picture and rich text message, MMS also allows mobile phone users to send and receive messages with video, audio and other digital content. In order to send and receive MMS messages, senders and recipients must have compatible mobile phones.

How it Works

When sending a MMS, the multimedia content is first encoded by the sending device. This is done in a similar way as sending an e-mail with Multipurpose Internet Mail Extensions (MIME) content. Once encoded, the MMS message is sent to a store and forward service in a mobile phone carrier's Multimedia Messaging Service Centre (MMSC). There, the message is forwarded to the recipient's phone. A high-speed 3G service, MMS message typically need mobile web or WAP features on the sending and receiving device. If the receiving device is subscribed with a different carrier, the message is relayed using the Internet to the MMSC of the recipient's service provider.

When the receiving device is MMS capable or compatible, the content of the message is sent to the recipient. This is done using WAP or mobile web technology. The MMS message is accessible directly on the device and the content is viewed using the device's messaging centre. Certain servers may adapt the content of the incoming message so it is formatted correctly on the receiving device. If the recipient's device is not MMS capable, a SMS message is sent to the recipient with a link to the message. This allows the user to view the message using a web-based service, such as an internet browser.

MMS Formats

Unlink SMS messages where senders can only transmit short text messages with plain text, MMS allows mobile phone subscribers the flexibility to send a range of digital content.

Text

MMS messages can include rich text with any character encoding when a subset of logical characters in Unicode is present. Unrecognized text subtypes will be displayed as plain text, if the character encoding is recognised by the device. Unlike Short Message Service (SMS) or text messages, MMS messages can include unlimited characters and be of any length. SMS messages are limited to up to 160 characters.

Pictures and Graphics

In addition to text, MMS messages may also feature picture and graphic content. Digital photographs in JPEG only and JPEG with JPEG File Interchange Format (JFIF) formats are generally supported by MMS capable devices. GIF and PNG bitmap graphics formats, as well certain Scalable Vector Graphics (SVG) formats are also supported when using MMS.

Video

Most digital movie and video files can also be send in MMS messages. Typically, the H.263 Profile 0 Level 10 video codec is supported when sending and receiving MMS messages. In addition, MMS generally supports the H.263 Profile 3 Level 10 and MPEG-4 Visual Simple Profile Level 0 video codec. The size of video and audio files may be limited by some mobile phone providers, which would require senders to use email rather than MMS to transmit data.

Audio

Audio is also compatible with MMS technology. MMS is generally capable of playing audio files with MPEG-4 AAC Low Complexity formats and a maximum sampling rate of 48 kHz. Both mono and stereo formats are typically compatible, and some devices may also support MPEG-4 AAC Long Term Prediction file formats. Synthetic audio formats such as Scalable Polyphony MIDI (SP-MIDI) formats are also supported by MMS. Narrowband and wideband peech files with the AMR codec should also be compatible with MMS.