Multi Mode Service (MMS)

Clear and vivid picture quality on large screen and CD like sound is the primary merit of digital broadcasting. Accordingly, transition to digital broadcasting in Korea started off from the beginning on the principle of providing a single high-quality broadcast per digital channel. The policy on high quality digital broadcasting pursued television broadcasting to develop from SDTV to HDTV to Full HDTV and to UDTV.

Nevertheless, due to the enhancement of the digital data compression and the digitization of signal intelligence over time, broadcasting the same quality of high-definition image and sound as in the past requires today much less transmission capacity than before. This means that there is still enough room in a single channel’s frequency range (6 MHz) even while transmitting a high-definition broadcast. In other words, along with the high-definition broadcast, it is now possible to provide various services to viewers without additional bandwidth.   

It is terrestrial Multi Mode Service (MMS) that has brought these possibilities to life. With MMS it is possible to broadcast one more HD program or provide various services that are combined into a multiplex system such as High-Definition (HD), Standard-Definition (SD) resolution, audio or data within the limit of a channel’s signal transmission capacity of 19.39 Mbps. MMS is also a technology that puts digital broadcasting apart from analogue broadcasting, whether it is a multi-channel or multi-mode type additional service. Despite all these benefits, MMS is not yet launched in Korea, whereas it is already commercialized in European countries and in the US, under slightly different names and forms. Even though technical problems that occurred in the early stage of the trial service are now resolved, there are reasons for this delayed launch, such as still persistent unequal growth between terrestrial and satellite/cable media broadcasting, conflicts of interests between stakeholders, and issues of how to define the nature of sub channels and how to regulate them.

Concept of MMS

MMS is a broadcasting technology allowing Standard Definition (SD), acoustic and sound data, on top of the basic HD images, to be provided within the TV channel’s permitted 6 MHz in various modes and forms as an additional service. For instance, channel number 3 can be divided into five virtual sub channels from 3.1 to 3.5; the existing high-definition broadcast for channel 3.1, standard broadcast for channel 3.2, audio broadcast for 3.3 and data broadcast for 3.4 and 3.5. 20151030

Read the source text