DAB and DAB+

DAB, also known as Digital Audio Broadcasting, is a radio transmission specification based on MPEG-1 Audio Layer 2 codec algorithm, and conceived in the 80s. However, in 2007 a new specification DAB+ was released based on the HE-AAC version 2 audio codec which provides better compression and audio quality. However, technology has moved on and today there are even better compression algorithms.

Usually, the codec is a digital signal processor (DSP) integrated circuit (IC), which processes a coding / decoding algorithm. This IC is usually a baseband processor and its job is to decode the digital signal. Hence, at the radio end, all of these new specifications simply mean different algorithms for the codec chip.

Some radios are capable of decoding both HE-AAC version 2, and MPEG-1 Audio Layer algorithms. Therefore, they are compatible with DAB, and DAB+ standards, however many earlier DAB radios will not be able to receive the new DAB+ transmissions. This is because the DAB+ standard is not backward compatible with DAB, as it relies on a completely different set of codec algorithms.

Many earlier digital radios used hardware based codec chips, however, with faster processors modern radios use software based codec chips. This means that some of those radios are upgradable through firmware upgrades. Digital radios are usually not future proof. Once a piece of technology relies on software, and computer hardware, you can be sure there will be new versions released periodically. Usually, the new versions perform better and are cheaper.

In the future, all digital radios will be upgradable through software. There will be a firmware upgrade channel, where the radio receives the new software and automatically upgrades itself, however this is far into the distant future.

This Article Continues...