Maximising Efficiency of Band III Spectrum

With a view towards the forthcoming Ofcom digital radio review and consultation, I've written quite a long article that looks at ways to maximise the efficiency of the Band III spectrum that is already available to DAB, and what is expected to be allocated to DAB in the UK. 

Band III provides far superior radio propagation characteristics than L-band, which is the other band that DAB can use. Therefore, the Band III spectrum should be used as optimally as possible so as to squeeze the maximum benefit from this prime spectrum real-estate. L-band will still have to be used anyway, because currently only 45% of analogue stations are on DAB, and there isn't enough available spectrum in Band III to fit all of these stations on Band III channels, and nor is it desirable to squeeze the smallest stations into Band III multiplexes when there is such a large amount of L-band available.

The article shows that the best use of Band III spectrum is by using national single-frequency network (SFN) multiplexes, and compares the DAB, DVB-H and DMB systems as to their suitability for use on Band III. 

The following table summarizes the relative efficiencies of DAB, DVB-H and DMB in terms of how many stereo stations they can carry in 7 MHz of Band III spectrum, which equates to 4 x DAB/DMB channels, or 1 x TV channel for DVB-H:

1 - 'same quality' denotes equivalent audio quality to 160kbps MP2

2 - 'higher quality' denotes equivalent audio quality to 192kbps MP2

3 - DMB uses BSAC (Bit Sliced Arithmetic Coding), which provides performance equivalent to the AAC codec