| |
|
|
|
|
|
 What is DMB?
The term DMB (Digital Multimedia Broadcasting) was originated from DAB(Digital Audio Broadcasting) which signifies ‘digital radio’. DAB, the broadcasting for ‘hearing only’ evolved into DMB, the broadcasting for ‘seeing and hearing’ in January to February, 2003. At that time, Korea Ministry of Information and communication (KMIC) standardized the term ‘DMB’ to describe the multimedia broadcasting services that include Audio as well as TV broadcasting and data, instead of ‘DAB’ since it was judged not appropriate to cover the meanings of those services.
|
|
|
|
|
 Type of DMB
DMB is classified into terrestrial DMB and satellite DMB according to its technology type and network configuration. Both services marked new epoch in mobile broadcasting, but their origins are different.
Furthermore, the technical specification of DMB is mainly classified into ‘System A’ and ‘System B’. System A is based on Orthogonal Frequency Division Multiplexing(OFDM), a standard for digital TV in Europe, while System B is based on code division multiplexing (CDM), a technology of same principle as mobile communication technology. The frequency bandwidth for terrestrial DMB and satellite DMB is different, as well as system type, respectively. Therefore, considerable time is expected to develop dual use terminal that is available for both terrestrial DMB and satellite DMB.
|
|
|
|
|
|
|
|
|
 |
Type |
 |
Terrestrial DMB |
|
Satellite DMB |
 |
|
|
Services |
|
Public and common service |
|
Commercial service |
|
|
System |
|
System A[Eureka-47] |
|
System -E[CDM] |
|
|
Frequency |
|
Bandwidth : 12MHz
- Ch12 : 204~210MHz
- Ch8 : 180 ~ 186 MHz |
|
Bandwidth : 25Mhz
- 2,630~2,655Mhz |
|
|
Resolution |
|
352 X 288 / 15 Frame |
|
240 X 320 / 15 Frame |
|
|
Coverage |
|
Seoul and surrounding areas first and expand into countrywide by district later |
|
Countrywide |
|
|
Channels |
|
per provider[total 6]
- 1 for video (total 6)
- 3 for audio (total 18)
- 1 for data(total 6) |
|
14 for videos
24 for audio
1 for data
|
|
|
Re-transmission of terrestrial television broadcasting |
|
Allowed |
|
Not allowed |
|
|
Business model |
|
Commercial |
|
Fixed charge + Commercial |
|
|
Estimated Launch |
|
Second half of 2005 |
|
May 2005 |
|
|
|
|
|
|
 History of DMB
DAB, a predecessor of terrestrial DMB was originated in Europe in the late 1980s. Counties in Europe organized a project group name ‘Eureka-147’ in 1987 to begin research for digital radio technology and BBC, a public broadcasting company, launched its terrestrial DAB service in September 1995. Since then, many countries in Europe introduced DAB service successively including Sweden in 1995, France in 1997, and Germany in 1999.
In Korea, KMIC organized ‘Promotion Conference for Terrestrial Digital Broadcasting (PCTDB)’ to discuss introduction of digital radio in March 1997, PCTDB suggested Eureka-147 as national standard in April 2001, and Eureka-147 was selected as standard for terrestrial DMB in December 2002.
The attempt to introduce Satellite DMB began with application of international patent for satellite network, which covers 135°, 144°, 154° east longitude, to International Telecommunication Union (ITU) by KMIC, under request of SK Telecom in September 2001. KMIC approved SK Telecom a one year experimental station for satellite DMB in November 2001, and selected ‘System E’, which was proposed by SK Telecom, as standard technology for satellite DMB in April 2003.
|
|
 What is terrestrial DMB?
The allocated VHF television channels for terrestrial DMB are channel 12 and channel 8. Also, more VHF channels are expected available for DMB around 2010, because the transmission of analogue television broadcasting will stop to change to digital broadcasting of terrestrial TV broadcasting after then.
The government plans to provide terrestrial DMB service for Seoul and surrounding areas first through VHF channel 12 and channel 8. And it plans to classify the areas into 5 districts of Chungchung, Chulla, Kangwon, Kyungsang, and Cheju and allocate one TV channel for each district for terrestrial DMB.
Under current frequency conditions, it is not easy for terrestrial DMB to broadcast nationwide by nationwide Single Frequency Network (SNF). The measures to help poor reception/out of service areas are being made by KMIC and the supply of repeaters was requested to Samsung and LG, terminal manufacturers.
However, such participation of private firms faced quite strong opposition since it will become market barrier for small manufacturers since it requires introduction of Network Identification System (NIS). 6MHz of frequency was divided into three frequency block (multiplex) and the provider was selected by each frequency block for terrestrial DMB. Bandwidth available to each provider is approximately 1.2Mbps. About 1.5~1.7Mbps of data transfer rate (bit-rate) can be attained ideally if a whole of one frequency block is used, however, approximately 1.2Mbps of data transfer rate can be used actually considering band-edge frequency (guard band), that is provided to prevent interference, and error correcting code.
Accordingly, each provider needs to divide 1.2Mbps into several audio and video channels. By applying `MPEG-4 Part10 AVC'(H.264), a cutting-edge compression technology with better compression efficiency as standard, two television channels can be loaded, or one television channel and several audio and data channels can be accommodated in one multiplex. Basically, this enables ‘multi-channel broadcasting’ by adopting better compression technology with high efficiency, though with some limitations. H.264 can realize image quality equivalent to a level of analog video tape (VHS). In this regard, additional benefits are also expected with expansion of DMB because many of the intellectual properties in H.264 video standard and MPEG-4 BSAC audio standard are held by domestic companies and research institutes.
|
|
|
|
 What is satellite DMB?
Satellite DMB service uses 2.630~2.655㎓ frequency range of UHF, which is far higher than that of the terrestrial DMB. Terrestrial DMB is based on land-base transmitting station, while satellite DMB is based on satellite in the field of outer space. The broadcasting center located in the ground transmits various multimedia contents to satellite through satellite frequency range (Ku-band, 12~13㎓), while the satellite transmits them to terminals in the ground through S-band of DMB frequency (2.630~2.655㎓).
For the places where difficult to receive atellite signals such as under the overpass and underground space, broadcasting signals can be received by using‘Gap-Filler’ repeater in the ground. The signal is transmitted through down frequency from satellite to Gap-Filler, and through S-band from Gap-Filler to customer’s terminals.
In case of satellite DMB, that uses omni-directional antenna to take advantage of mobile reception, there are many shadow areas and, thus, ground repeater is necessary to provide multimedia broadcasting due to frequency characteristics of Ku-band.
The system E which is estimated to be established as national technology standard by this September is based on the CDMA so as to use allow multiple users to use same frequency range simultaneously by allocating each code to them. It is a transmission technology with proven excellence through mobile phone service. Since services based on CDMA, a world-competitive technology, have been provided in Korea, it is considered that chances are in Korea’s favor in development and commercialization of chip, terminal, repeater, etc.. Though the patent right for System-E is held by Toshiba of Japan, it is said that Korea has advantage over Japan in commercialization of chip, terminal, repeater, etc.
|
|
 Available Areas
Satellite DMB receives signals through broadcasting satellite, while terrestrial DMB receives signals through land-base transmitting station, located in top of Namsan, Kwanak, and Yongmun mountains Therefore, terrestrial DMB has more poor reception/out of service areas than satellite DMB.
At the beginning of service, terrestrial service is available only in Seoul and surrounding areas, and is unavailable in underground and some indoor spaces, this means the service is available in the areas where FM radio broadcasting is available at current stage.
Satellite DMB, which is in commercial broadcasting now, is also unavailable in Seoul subway lines 5 to 8, Pusan, Kwangju, Daegu and Daejeon subway lines, underground and some indoor spaces of building, currently.
In order to relieve such problem, it is planned to install repeaters in poor reception/out of service areas so that the satellite DMB services are available everywhere. For terrestrial DMB, it is planned to sectionize the nation and install repeaters.
|
|
|
|
 Availability of both satellite DMB service and terrestrial DMB service by using one terminal.
It is impossible to use both DMB services by using one receptor currently like different set-top box is used for satellite broadcasting and cable broadcasting.
Thus, different receptor shall be used for satellite and terrestrial DMB services, respectively. It can be possible if the dual use terminal, which is good for both DMB services, is developed, however, it is thought to be unmarketable due to high unit price of such terminal. Therefore, customers needs to decide which DMB service they will use before buying terminal. DMB service is unavailable with typical mobile phones or PDAs. It is necessary to buy a dedicated terminal such as DMB phone to use DMB service.
|
|
 Contents
Terrestrial DMB service can retransmit about 60% of terrestrial broadcasting programs. Thus, it is not critical to focus on development of dedicated contents for DMB service, but it is necessary to develop various contents such as dedicated mobile channel, specialized music channel by genre, and information service for songs.
Terrestrial broadcasting companies including KBS and MBC recently decided not to provide their programs to satellite DMB providers until terrestrial DMB service is established firmly. Accordingly, TU media will transmit separate programs such as US major league baseball games.
|
|
 Service Charges
It is planned to provide service free of charge for terrestrial DMB service, and fee charged for satellite DMB service. In case of satellite DMB service, two thousand Won will be charged for membership and thirteen thousand for basic rate per month for 12 video channels and 22 audio channels.
TU media plans to expand more channels to provide as premium services. There is possibility that terrestrial DMB service will be operated as charged service which was originally planned as free service by Government.
Government planned to accommodate deficit by commercial to maintain free service but providers are requesting to change into pay service because approximately 40 to 50 billion Won of additional cost is expected to install additional repeaters in poor reception/out of service areas.
The providers proposed to charge about four thousand Won per month for their services. Nevertheless, civic groups, including People’s Coalition for Media Reform, opposes to change into pay service for terrestrial DMB service because pay service of terrestrial DMB service violates basic right of citizens as well as causes sensationalism.
|
|
 Type of DMB terminals
VMT to be mounted on motor vehicles, mobile phone, PDA, PC terminals, etc. will be released. Existing DMB terminals are for satellite DMB service and includes mobile phone, VMT, etc.. DMB terminals for terrestrial DMB service will be sold by us and includes VMT, mobile phone, PDA, etc.
In case of VMT, no battery is used and on-board power supply is used, resulting in elimination of trouble for play hours, and 7 inch of large screen is provided, And, thus, is very promising in future sales.
|
|
|
|
