ISDB-T International - Technical Facts

Technical Facts

a) Modulation: BST-OFDM (Band Segmented Transmission-Orthogonal Frequency Division Multiplexing).

b) Frequency Band: VHF or UHF, according to the country implementation strategy. UHF is a very affordable band once it is possible to implement digital services in current UHF "spaces" in broadcasting spectrum while analog services are still running in "jammed" VHF band. After digital TV implementation rollout is finished and analog signal is cut off, then VHF can be used for other services or even to expand digital services to more broadcasters. Japan, Philippines, and Brazil have chosen UHF. Peru, Argentina, Chile and Venezuela are in implementation design phase, so the band to be used was not defined.

The ISDB system can also work based in cable or satellite transmission (ISDB-C and ISDB-S) using appropriate frequency band, but these standards are outside the scope of this arcticle.

c) Transmission architecture: Segmented

• Non-Mobile receivers: 13 segments (for Full HD resolution.

Other arrangements possible according to the desired resolution/number of programs transmitted)

• Mobile receivers (in vehicles for example): The same as Non-Mobile
• Portable receivers (mobile phones for example): 1 segment

d) Frame Rate:

• Non-Mobile/Mobile service: Japan, Peru, Argentina (also 25 frame/s and 50 frame/s), Brazil, Chile, Venezuela and Ecuador: 30 frame/s and 60 frame/s
• Portable service: Brazil, Peru, Argentina, Chile, Venezuela, Philippines and Ecuador: Maximum of 30 frame/s; Japan: Maximum of 15 frame/s

e) Channel Bandwidth: Japan, Brazil, Peru, Argentina, Chile, Venezuela and Ecuador: 6 MHz (It is possible to use SBTVD/ISDB-T system with 13 segments in 7 MHz or 8 MHz if that is required by any country. Maldives is the first country to adopt ISDB-T with 8 MHz channel bandwidth.)

f) Audio Compression System:

• Non-Mobile/Mobile service:
  • Multi Channel 5.1: MPEG-4 AAC@L4 (Advanced Audio Coding, Level 4) or MPEG-4 HE-AAC v1@L4 (High Efficiency AAC, Version 1, Level 4)
  • Stereo: MPEG-4 AAC@L2 (AAC Level 2) or MPEG-4 HE-AAC v1@L2 (HE-AAC, Version 1, Level 2)

• Portable service: MPEG-4 HE-AAC v2@L2 (HE-AAC, Version 2, Level 2) for stereo audio (or 2 mono channels) only.

All compression systems must be conform to ISO/IEC 14496-3:2004 standard. The Allowed transport mechanisms LATM/LOAS.

Note: Japan uses MPEG-2 AAC for non-mobile/mobile service and MPEG-4 HE-AAC for portable service. The Allowed transport mechanisms ADTS

g) Video Compression System:

• Non-Mobile/Mobile: MPEG-4 AVC HP@L4 (Advanced Video Coding, High Profile, Level 4)

• Portable: MPEG-4 AVC BP@L1.3 (AVC, Base Profile, Level 1.3)

Also, video codification must be conform to ISO/IEC 14496-10:2005 standard.

These standards are also known as ITU-T H.264:2005 Recommendation.

Note: Japan uses MPEG-2 video.

h) Video Resolution, Framing and Aspect Ratio:

• Non-Mobile/Mobile:
  • SD 720x480i at 4:3 or 16:9
  • SD 720x480p at 4:3 or 16:9
  • SD 720x576i at 4:3 or 16:9
  • SD 720x576p at 4:3 or 16:9
  • HD 1280x720p at 16:9
  • Full HD 1920x1080i at 16:9
    • Note: i = interlaced framing; p = progressive framing

• Portable:
  • SQVGA (160x120 or 160x90)
  • QVGA (320x240 or 320x180)
  • CIF (352x288)
    • All these formats using 4:3 or 16:9 aspect ratios.

i) Multiplexing system: MPEG-2 system (ISO/IEC 13818-1 2000). That standard is used by Japan, Brazil, Peru, Argentina, Chile, Venezuela and Ecuador.

j) Processes for Error Correction: Time Interleaving and Frequence Interleaving

k) Interactive TV middleware:

• ISDB-T: Declarative: BML; Procedural: Not implemented - Optional GEM
• SBTVD/ISDB-T International: Declarative: Ginga-NCL; Procedural: Ginga-J

l) Other carcteristics:

• Multiprogram:

Allows 1 program Full HD (1920 x 1080 dots at 16:9 aspect ratio) in a channel; or 1 program HD and 1 program SD in a channel; or 3 programs SD in a channel.