AAC+ being tested on DAB in the UK

9th October 2006

I've been informed that streams using the AAC+ audio codec are to be tested on the Stoke local DAB multiplex this week. The Stoke multiplex is presumably being used because it is only half full.

AAC+ streams are also being tested on DAB in Australia.

Both tests are using multiplexing equipment designed by Radioscape.

It will be interesting to see what bit rates are being tested, and to see some of the things that will be included in the forthcoming DAB+ specification, such as:

whether Unequal Error Protection (UEP) is used with AAC+ services or whether they're limiting it to Equal Error Protection (EEP) — the DRM system uses UEP with AAC+, and the current DAB specification states that UEP profiles are possible for non-MP2 audio services
whether MPEG-4 Audio Version 2 Error Resilience tools, and if so, whether the Error Robustness (ER) and/or Error Protection (EP) tools are being used — again, the DRM system uses these tools
whether variable bit rate (VBR) will be supported to allow statistical multiplexing

I'm taking it as a given that Reed-Solomon error correction will be used.