Multimedia Messaging Service (MMS) is a standard for telephone messaging systems that allows sending messages that include multimedia objects (images, audio, video, rich text) and not just text as in Short Message Service (SMS). It is mainly deployed in cellular networks along with other messaging systems like SMS, Mobile Instant Messaging and Mobile E-mail. Its main standardization effort is done by 3GPP, 3GPP2 and Open Mobile Alliance (OMA).
MMS is the evolution of Short Message Service (SMS, which is a text-only messaging technology for mobile networks). It allows the sending and receiving of multimedia messages such as graphics, video and audio clips. It has been designed to work with mobile packet data services such as GPRS and 1x/EVDO.
MMS-enabled mobile phones enable subscribers to compose and send messages with one or more multimedia parts. Multimedia parts may include text, images, audio and video. These content types should conform to the MMS Standards. For example your phone can send an MPEG-4 video in AVI format, but the other party who is receiving the MMS may not be able to interpret it. To avoid this, all mobiles should follow the standards defined by OMA. Mobile phones with built-in or attached cameras, or with built-in MP3 players are very likely to also have an MMS messaging client—a software program that interacts with the mobile subscriber to compose, address, send, receive, and view MMS messages.
MMS was originally developed within the Third-Generation Partnership Program (3GPP), a standards organization focused on standards for the UMTS/GSM networks.
Since then, MMS has been deployed world-wide and across both GSM/GPRS and CDMA networks.
MMS has also been standardized within the Third-Generation Partnership Program 2 (3GPP2), a standards organization focused on specifications for CDMA2000 networks.
As with most 3GPP standards, the MMS standards have three stages:
Stage 1 – Requirements (3GPP TS 22.140)
Stage 2 – System Functions (3GPP TS 23.140)
Stage 3 – Technical Realizations
Both 3GPP and 3GPP2 have delegated the development of the Stage 3 Technical Realizations to the OMA, a standards organization focused on specifications for the mobile wireless networks.
GSM Association has produced a MMS Interworking Guidelines IR.52 document for MMS interconnection between GSM operators.
Challenges faced by MMS
There are some interesting challenges with MMS that do not exist with SMS:
Content adaptation: Multimedia content created by one brand of MMS phone may not be entirely compatible with the capabilities of the recipients’ MMS phone. In the MMS architecture, the recipient MMSC is responsible for providing for content adaptation (e.g., image resizing, audio codec transcoding, etc.), if this feature is enabled by the mobile network operator. When content adaptation is supported by a network operator, its MMS subscribers enjoy compatibility with a larger network of MMS users than would otherwise be available.
Distribution lists: Current MMS specifications do not include distribution lists nor methods by which large numbers of recipients can be conveniently addressed, particularly by content providers, called Value Added Service Providers (VASPs) in 3GPP. Since most SMSC vendors have adopted FTP as an ad-hoc method by which large distribution lists are transferred to the SMSC prior to being used in a bulk-messaging SMS submission, it is expected that MMSC vendors will also adopt FTP.
Bulk messaging: The flow of peer-to-peer MMS messaging involves several over-the-air transactions that become inefficient when MMS is used to send messages to large numbers of subscribers, as is typically the case for VASPs. For example, when one MMS message is submitted to a very large number of recipients, it is possible to receive a delivery report and read-reply report for each and every recipient. Future MMS specification work is likely to optimize and reduce the transactional overhead for the bulk-messaging case.
Handset Configuration: Unlike SMS, MMS requires a number of handset parameters to be set. Poor handset configuration is often blamed as the first point of failure for many users. Service settings are sometimes preconfigured on the handset, but mobile operators are now looking at new device management technologies as a means of delivering the necessary settings for data services (MMS, WAP, etc.) via over-the-air programming (OTA).
WAP Push: Few mobile network operators offer direct connectivity to their MMSCs for content providers. This has resulted in many content providers using WAP push as the only method available to deliver ‘rich content’ to mobile handsets. WAP push enables ‘rich content’ to be delivered to a handset by specifying the URL (via binary SMS) of a pre-compiled MMS, hosted on a content provider’s web server. A downside of WAP push is that from a billing perspective this content is typically billed at data rates rather than as an MMS. These charges can be significant and result in ‘bill shock’ for consumers.
Although the standard does not specify a maximum size for a message, 300 kB is the current recommended size used by networks due to some limitations on the WAP gateway side.
MMS should not be confused with Enhanced Messaging Service (EMS), which is simply Short Message Service (SMS) with additional payload capabilities, allowing a mobile phone to send and receive messages that have special text formatting (such as bold or color), animations, pictures, icons, sound effects, and special ring tones.
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