Doubt has again been cast on the viability of the centerpiece of the Federal Government’s digital media policy, the so-called A and B channels for digital television.

Channel A is supposed to be a narrowcasting channel for non-commercial programming. Channel B is also a narrowcasting channel but is of a more commercial nature with mobile TV supposedly the major area of interest.

At the moment there is only one group interested in both: the Macquarie bank backed Broadcast Australia.

While it is trying to snare a deal to get the federal Government to pay it to carry community TV on Channel A, the technical questions about the reliability of the supposedly more lucrative Channel B licence in Sydney, Australia’s most important and biggest media market; and in the near Brisbane markets around the Gold Coast, are the major worry.

From testimony at last week’s Senate Estimates hearings in Canberra, it appears the Government and its key regulator, ACMA, are no closer to resolving these issues than they were late last year when the problems first emerged.

In fact they seem to be intractable at the moment, especially in Sydney where the operation of the full range of 30 narrow casting channels seems impossible without a prohibitive amount of capital spending to make the most attractive use, mobile TV, work alongside free to air TV without significant interference.

Exchanges at Senate estimates this week go someway to explaining the problem.

It starts with Giles Tanner, a senior officer of ACMA:

Mr Tanner: “The issue is that mobile television has different network transmission architecture from fixed television. You would probably need more infill transmitters than you would with fixed television. The difficultly that the Sydney channel experiences is that it is quite hard to build additional infill transmitters other than those that are used by fixed television without causing interference to television services on nearby channels. So that, if you like, is your black-spot problem.

Senator Conroy: What is the technological solution?

Mr Tanner: This is a very complicated issue.

Senator Conroy: What is the footprint of the problem? Is it a 10 per cent of the land mass area in Sydney, one per cent or five per cent?

Mr Tanner: No, it is not a question that has got one answer, because it depends. The answer is: it depends. It depends on the configuration that you run the service with.

Senator Conroy: But no configuration has a zero problem?

Mr Tanner: There is no configuration or modulation you can run that just fixes the problem magically, no. The point is not that it is impossible to put in the infills; it is that there will be costs entailed in fixing the interference problems that prevent you from using that channel. Those costs may, at the discretion of a market participant, be prohibitive. That is the issue.

Senator Conroy: So the extra cost of actually making it a universal service within Sydney could be prohibitive?

Mr Tanner: Yes.

The federal Government and ACMA know that if they switched analogue TV off tomorrow (impossible because of the slow pace of conversion) Channels A and B would be worthless because all the spectrum currently being used by analogue TV networks would be available to be sold or taken up in new services.

And if Channels A and B don’t really work and produce an expansion of diversity and choice, the whole Government media law changes will be exposed for what they were in reality: a free gift from John Howard of billions of dollars of value to the likes of the Packer family, Kerry Stokes, Macquarie Bank and one or two others. And zilch to consumers.