Technically most of the options are already known: mobile TV; ‘standard’ mobile telephony - particularly expanding coverage in rural areas; wireless broadband, terrestrial High Definition Television (HDTV); additional standard definition TV channels or interactive services. There is also the wildcard of what the European Commission calls ‘innovative new services’, which could mean things not invented yet but so far has generally meant mobile TV.

So which one of these will bring the most benefits to society at large? OK, journalistic oversimplification, which combination of these will bring the most benefit?

I ask the question because a substantial body of opinion believes social interests are best served by allocating the released frequencies – or digital dividend – to terrestrial HDTV. HDTV requires substantially more spectrum than standard definition and approximately eight terrestrial HDTV channels would swallow up the entire digital dividend.

The arguments in favour? HDTV is the next big thing. If you can’t offer it on digital terrestrial TV (DTT) then this will always be a sub-standard platform compared to satellite or cable, allowing Rupe to extend his grip.

Furthermore, how is the public going to feel, having been told by the government to buy a digital set-top box, then being told they need to buy another box to receive HDTV, by then the de facto standard (Arguments well put at City University’s recent seminar on digital switchover – see PolicyTracker 23.5.06)

The arguments against? Cable or satellite is the natural HDTV platform. It has the bandwidth to offer as many HDTV channels as people could wish for, as well as far superior interactivity.

A more interesting question is whether society would prefer mobile TV or terrestrial HDTV channels? Which brings greater benefits, HDTV or widespread wireless broadband access, perhaps enabling mobile VoIP calls? How do you assess the respective social and economic benefits? This is one of the things Ofcom’s Digital Dividend Review is trying to do.

However, the terrestrial HDTV lobby has its work cut out. Its arguments are mainly about the social benefits and Ofcom is well known for taking an economist’s approach to most subjects. It certainly favours a market approach to spectrum, raising the question of whether TV companies could afford to buy the spectrum required for HDTV.

But it’s still a fascinating question. Which would bring the greatest benefit to society: HDTV; mobile TV; extending existing mobile services; wireless broadband; or leaving the space for as yet unspecified new services?

Martin Sims is the co-editor of the spectrum policy newsletter PolicyTracker and most of the links are to articles in the publication. You can read them by taking out a one month free trial.