Digital Terrestrial Broadcasting

3. Outline and Trend of Digital Terrestrial Broadcasting

(1) Outline of Digital Terrestrial Broadcasting System Recommendation by ITU-R

	System A (ATV USA)	System B (DVB-T Europe)	System C (ISDB-T Japan)
	Television
Picture Coding Method	MPEG-2 Video
Sound Coding Method	Dolby AC3	MPEG-2 Audio (BC)	MPEG-2 Audio AAC
Multiplexing Method	MPEG-2 Systems
Bandwidth	5.38 MHz (-3 dB)	7.61 MHz	5.6 MHz
Number of Carriers	1	1705/6817	1405/2809/5617
Modulation Method	8VSB	OFDM QPSK/16 QAM/64 QAM MR 16 QAM/MR 64 QAM	OFDM DQPSK/QPSK/ 16 QAM/64 QAM
Error Correction Internal Code (Coding Rate)	Trellis-Coded (2/3)	Punctured convolution (1/2, 2/3, 3/4, 5/6, 7/8)	Punctured convolution (1/2, 2/3, 3/4, 5/6, 7/8)
Reed-Solomon Code	RS(207, 187)	RS(204, 188)	RS(204, 188)
Baud Rate	19.39 Mbps	Max. 31.67 Mbps	Max. 23.2 Mbps
Transmission Spectrum
Remarks	The VSB data frame common to both NTSC format and frequency is used.	Select the number of carriers according to whether the SFN structure is required.	Select the number of carriers according to whether the SFN structure is required, or whether the mobile stations can receive the signal.
Number Recommended	BT.1306, BT.1206

	System A (DAB)	System F (ISDB-TSB)
	Sound
Picture Coding Method	-	-
Sound Coding Method	MPEG-1 Layer II	MPEG-2 Audio AAC
Multiplexing Method	Dedicated	MPEG-2 Systems
Bandwidth	1.5 kHz	428 kHz/segment
Number of Carriers	192/384/1536	108/216/432 per segment
Modulation Method	OFDM DQPSK	OFDM DQPSK/QPSK/ 16 QAM/64 QAM
Error Correction Internal Code (Coding Rate)	Convolution	Punctured convolution (1/2, 2/3, 3/4, 5/6, 7/8)
Reed-Solomon Code	-	RS(204, 188)
Baud Rate	Approx. 1.2Mbps	Max. 1.79Mbps*
Transmission Spectrum	-	-
Remarks	Select the number of carriers for each frequency band.	* 64QAM/segment 3 segment acceptable
Number Recommended	BS.1114-2

(2) DVB-H/DAB - Candidate of Potable TV in Europe

Developing Technologies
Transmission Method	DVB-H	DAB Applicable to Multimedia	ISDB-T (1 Segment Broadcasting)
Regions Probably Introduce	Europe (e.g., Finland, Germany)	South Korea, Europe, etc (*1)	Japan
Developing Schedule	Working Group of DVB has decided the specification of DVB-H in the spring of 2004.	The basic technology has been developed; put to practical use in 2004.	The 1 segment broadcasting has been started on 1 April, 2006.
Manufacturers positive for developing the reception terminal	NOKIA in Finland, ROYAL PHILIPS ELECTRONICS in Netherlands, etc.	SAMSUNG ELECTRONICS, FREESAT KOREA in South Korea	MITSUBISHI, NEC, SANYO in Japan, etc.

Basic Technology
Transmission Method	DVB-H	DAB Applicable to Multimedia	ISDB-T (1 Segment Broadcasting)
Transmission Method	DVB-T(digital video broadcasting-terrestrial)	DAB(digital audio broadcasting)	ISDB-T (13 segment broadcasting)
Time of Standardization/ Practical Use	The DVB-T specifications are planned by DVB and approved as standards by ETSI in 1997. The commercial broadcasting is spreading for Germany and Northern Europe as well as UK started in 1998.	The DAB specifications are planned by Eureka 147 Project and approved as standard in 1995. The commercial broadcasting started in 1998 is spreading for Europe and Asia such as Singapore, Germany, and South Korea, etc.	The ISDB-T is a digital terrestrial broadcasting system approved as standards by ARIB. The commercial broadcasting started in December, 2003 is now spreading for a part of Kanto, Chukyo, and Kinki areas.
Transmission Method	OFDM (Number of carriers: 1705 for 2K Mode, 6817 for 8K Mode)	OFDM (Number of carriers: 1536 for Mode I, 384 for Mode II)	OFDM (Number of carriers: 1405 for Mode 1, 2809 for Mode 2, 5617 for 8K Mode 3)
Carrier Modulation Method	Select from QPSK, 16QAM, and 64QAM.	DQPSK	Select from DQPSK, QPSK, 16QAM, and 64QAM
Frequency Used	VHF/UHF band	Band III (174 MHz to 245 MHz) and L-Band (1.45 GHz to 1.492 GHz) are mostly used.	VHF/UHF band
Bandwidth per Channel	7MHz/8MHz	1.54MHz	6 MHz. In one segment broadcasting, about 429 kHz (1/13 of the bandwidth) is used.
Baud Rate per Channel	Approx. 32 Mbit/sec max. (for bandwidth of 8 MHz)	In UK, data area in Band III is 256k bit/sec.	280 kbit/sec to 561 kbit/sec (for 1 segment broadcasting)

*1 : In South Korea, the terrestrial DMB (Digital Multimedia Broadcasting) system used for mobile stations has been started in December, 2005.
The terrestrial DMB is a transmission method based on DAB and approved as standards by ETSI (European Telecommunications Standards Institute) in June, 2005.