DAB vs DVB vs DMB: Digital Broadcasting Technologies Explained

This article breaks down the key differences between DAB, DVB, and DMB technologies. These are all digital broadcasting standards, but they serve different purposes and have unique features.

DAB - Digital Audio Broadcasting

DAB is a digital radio technology that transmits radio frequency waves to deliver digital audio services. If you have a DAB receiver, you can pick up these broadcasts. It’s available in many countries across Europe and the Asia Pacific region.

DAB was specifically designed for terrestrial mobile reception, so you can listen in your car without issue.

Here are some key features and advantages of DAB:

• Frequency Bands: DAB uses four frequency bands, or modes, globally:
  • Mode-I: Band-III (174 to 240 MHz)
  • Mode-II and Mode-IV: L Band (1452 to 1492 MHz)
  • Mode-III: Frequencies below 3 GHz
• Improved Audio Quality: Most DAB stations use 128 Kbps, offering a better Signal-to-Noise Ratio (SNR) compared to traditional FM radio.
• OFDM and Advanced Modulation: DAB employs Orthogonal Frequency-Division Multiplexing (OFDM) with modulation schemes like DQPSK. This allows for high data rates and simultaneous transmission of multiple programs while also reducing interference.
• Multiple Services: DAB can deliver 9 to 10 services simultaneously on a single frequency.
• Beyond Audio: DAB can also transmit data, weather maps, traffic information, mobile TV, and even stock information.

DVB - Digital Video Broadcasting

DVB is an open standard for digital television broadcasting. Several variations of the standard exist to cater to different broadcasting methods, including DVB-T (Terrestrial), DVB-S (Satellite), DVB-C (Cable), and DVB-H (Handheld).

Here’s what makes DVB stand out:

• OFDM and Complex Modulation: DVB utilizes OFDM coupled with advanced modulation techniques like QPSK, 16-QAM, and 64-QAM.
• Forward Error Correction (FEC): Techniques like LDPC and BCH are employed to enhance reception quality and provide robust error correction at DVB receivers.
• Interleaving: DVB uses various interleaving methods (bit, time, frequency) to handle interference and signal fading.

For more in-depth information, you can research “Digital TV basics.”

DMB - Digital Multimedia Broadcasting

DMB is a digital radio technology engineered for transmitting radio, TV, and data to mobile devices, including GPS receivers. South Korea developed this technology with the goal of replacing FM radio.

DMB operates in two modes: satellite-based (DMB-S) and terrestrial (DMB-T). It’s quite similar to other mobile TV standards like DVB-H.

Key aspects of DMB:

• Frequency Bands: DMB-T operates in frequency band III and L band.
• Video and Audio Encoding: DMB-T uses MPEG-4 part-10 (H.264) for video and MPEG-4 part-3 BSAC (HE-AAC V2) for audio. Both video and audio are encapsulated within an MPEG-TS (Transport Stream).
• Error Correction: DMB uses FEC techniques, such as Reed-Solomon (RS) encoding, to deliver high-quality reception with error correction capabilities, mitigating interference and fading.
• OFDM-DQPSK: The OFDM-DQPSK modulation technique allows for high data rates and simultaneous transmission of multiple programs.