Digital Terrestrial Multimedia Broadcast


Digital Terrestrial Multimedia Broadcast
List of digital television broadcast standards
DVB standards (Europe)
DVB-S (satellite)
DVB-T (terrestrial)
DVB-C (cable)
DVB-H (handheld)
ATSC standards (North America/Korea)
ATSC (terrestrial/cable)
ATSC-M/H (mobile/handheld)
ISDB standards (Japan/Latin America)
ISDB-S (satellite)
ISDB-T (terrestrial)
ISDB-C (cable)
SBTVD/ISDB-Tb (Brazil)
DTMB standards (China)
DTMB-T/H (terrestrial/handheld)
CMMB (handheld)
DMB standards (Korean handheld)
T-DMB (terrestrial)
S-DMB (satellite)
MediaFLO
Codecs
Video
Audio
Frequency bands
VHF
UHF
SHF
v · d · e

DTMB (Digital Terrestrial Multimedia Broadcast) is the TV standard for mobile and fixed terminals used in the People's Republic of China, Hong Kong and Macau. Although at first this standard was called DMB-T/H (Digital Multimedia Broadcast-Terrestrial/Handheld), the official name is DTMB.

Digital broadcast standards.svg

DTT broadcasting systems. Countries using DTMB or DMB-T/H are shown in red.

Contents

Overview

The DTMB is a merger of the following standards: ADTB-T (developed by the Shanghai Jiao Tong University, Shanghai), DMB-T (developed by Tsinghua University, Beijing) and TiMi (Terrestrial Interactive Multiservice Infrastructure), which is the standard proposed by the Academy of Broadcasting Science in 2002.

At first, neither Shanghai Jiao Tong University nor Tsinghua had not enough political strength to make their own technology being the unique standard, so the final decision was to opt for a double standard, merged with theTIMI 3 standard, responding to a need of backward compatibility.

The DTMB was created in 2004 and finally became an official DTT standard in 2006.

DTMB in China

  • 2005 trial
  • 18/08/2006 formal adoption as a DTT standard
  • 2008 analogue to digital switchover
  • 2015-2018 analog switchoff

DTMB in Hong Kong

  • 18/08/2006 formal adoption as a DTT standard
  • 31/12/2007 analogue to digital switchover
  • 2015 analogue switchoff

DTMB in Macau

  • 18/08/2006 formal adoption as a DTT standard

Versus CMMB

See China Multimedia Mobile Broadcasting (CMMB).

Countries and territories using DTMB

Asia

Middle East

Description

Besides the basic functions of traditional television service, the DTMB allows additional services using the new television broadcasting system. DTMB system is compatible with fixed reception (indoor and outdoor) and mobile digital terrestrial television.

  • Mobile reception: is compatible with digital broadcasting TV in standard definition (SD), digital audio broadcasting, multimedia broadcasting and data broadcasting service.
  • Fixed reception: in addition to the previous services, also supports high definition digital broadcasting (HDTV).

Modulation

The DTMB standard uses many advanced technologies to improve their performance, for example, a pseudo-random noise code (PN-Pseudo-random Noise) as a guard interval that allows faster synchronization system and a more accurate channel estimation , LDPC (Low-Density Parity-Check) encoding to protect against mistakes, modulation TDS-OFDM (Time Domain Synchronization - Orthogonal Frequency Division Multiplexing) which allows the combination of broadcasting in SD, HD and multimedia services, etc.

This system gives flexibility to the services offered to support the combination of Single Frequency Networks (SFN) and Multiple Frequency Network (MFN). The different modes and parameters can be chosen depending on the type of service and network's environment.

The sequence of pseudo-random pattern is defined in time domain and the information of the Discrete Fourier Transform (DFT) is defined in the frequency domain. The two frames are multiplexed in the time domain, resulting in the Time Domain Synchronization (TDS).

Functional scheme

This transmission system makes the conversion of the input signal to the output data of terrestrial TV signal.

The data passes through the encoder, the error protection process FEC (Forward Error Correction), through the constellation mapping process and then the interleaving processes the information to create the data blocks. The data block and the TPS information are multiplexed, and pass through the data processor to form the body structure. It combines information from the body and the head to form the frame and this is passed through the SRRC (Square Root Raised Cosine) filter to become a signal within a 8MHz channel bandwidth. Finally the signal is modulated to put it in the corresponding frequency band.

Features

  • Bit-rate: from 4.813Mbps to 32.486Mbps
  • Combination of SD, HD, and multimedia services
  • Flexibility of services
  • Time and frequency domain of data-processing
  • Broadcasting of between 6 and 15 SD channels and 1 or 2 HD channels
  • Same quality of reception as wire broadcast

Further reading

  • Kumar, Amitabh (2007). Mobile TV: DVB-H, DMB, 3G Systems and Rich Media Applications. Focal Press Media Technology Professional Series. Focal Press. ISBN 978-0-240-80946-5. 

See also


External links



Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Digital terrestrial television — List of digital television broadcast standards DVB standards (Europe) DVB S (satellite) DVB S2 DVB T (terrestrial) DVB T2 DVB C …   Wikipedia

  • Digital radio — has several meanings: 1. Today the most common meaning is digital radio broadcasting technologies, such as the digital audio broadcasting (DAB) system, also known as Eureka 147. In these systems, the analog audio signal is digitized into zeros… …   Wikipedia

  • Digital radio in the United Kingdom — A typical DAB digital radio receiver with the Digital Radio Development Bureau DAB digital radio marketing logo In the United Kingdom, the roll out of digital radio is proceeding since test transmissions were started by the BBC in 1990. The UK… …   Wikipedia

  • Digital Video Broadcasting — Official DVB logo, found on compliant devices List of digital television broadcast standards …   Wikipedia

  • Digital Multimedia Broadcasting — DMB on a Samsung phone in South Korea List of digital television broadcast standards DVB standards (Europe) …   Wikipedia

  • Digital television — List of digital television broadcast standards DVB standards (Europe) DVB S (satellite) DVB S2 DVB T (terrestrial) DVB T2 DVB …   Wikipedia

  • Digital television in Malaysia — See digital television for more technical details, or DTV transition in the United States for specific information related to the analog to digital switchover In Malaysia, digital television broadcasts, or DTV, can be received via cable, internet …   Wikipedia

  • Multimedia Home Platform — (DVB MHP) is an open middleware system standard designed by the DVB project for interactive digital television. The MHP enables the reception and execution of interactive, Java based applications on a TV set. Interactive TV applications can be… …   Wikipedia

  • Digital Radio Mondiale — (abbreviated DRM; mondiale being Italian and French for worldwide ) is a set of digital audio broadcasting technologies designed to work over the bands currently used for AM broadcasting, particularly shortwave. DRM can fit more channels than AM …   Wikipedia

  • Multimedia over Coax Alliance — (MoCA) is a trade group promoting a standard that uses coaxial cables to connect consumer electronics and home networking devices in homes. It allows both data communication and the transfer of audio and video streams. Contents 1 History 2 MoCA 1 …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.