The RTE Authority is expected to have a detailed submission on the future of digital television in Ireland ready for the Government by September. Yesterday the authority heard a submission on how Ireland should move into the digital future from Mr Peter Branagan, the director of technology with special responsibility for developing digital television policy.

RTE commissioned the London-based consultants, the Convergence Decision Group, to analyse the Irish position and come up with recommendations.

They told RTE that Ireland should develop a terrestrial digital system, similar to that favoured by the UK authorities. This would be the cheapest to develop and give Ireland about 30 channels.

It has also recommended that RTE develop the system for this country in conjunction with a strategic partner from the private sector, possibly a foreign telecom company.

The cost for Ireland of going digital will be in the region of £40 to £45 million, or a capital cost of £30 to £35 per household. To convert RTE's own production facilities will cost tens of millions of pounds.

According to one RTE source, the report from the consultants is the first independent analysis. It recommends Digital Terrestrial Television (DTT) as the cheapest delivery system for Ireland, partly because it uses the existing infrastructure.

DTT would transmit from the same sites currently owned by RTE, after the transmitters have been changed for digital broadcasting. It demands no special dishes or cables and can be picked up by ordinary aerials, even indoor ones in most areas.

If the authority accepts the arguments, which are believed to be supported by senior staff in RTE, the conversion will pay for itself by the sale of the current analogue transmission system to the private sector, the sale of RTE's share in CableLink, and the sale of an equity stake in the digital network.

The plan, as presented to the authority, would see digital television being introduced here in late 1999.

It would be offered to viewers on several tiers. The first would give a range of Irish channels, including the two present RTE channels, TnaG, TV3 (which it is assumed will be up and running) and a range of British channels.

It might also offer RTE Plus, a "time shift" channel which would offer RTE's programmes at different times, giving viewers a chance to catch up on what they missed. It would also enable viewers to see their favourite American import on RTE instead of on a British channel.

Other tiers would offer more and more channels, so long as they were paid for. Viewers would have a set-top box to unscramble the signal, which would accept a "smart card", making licence-fee collection much more efficient.

A 24-hour news service could be offered in conjunction with the BBC and possibly Euronews.

Viewers could see recent films on a pay-per-view basis.

Digital would also allow local opt-outs or stations offering local news, discussion programmes or quizzes.

The consultants had three options to consider, digital terrestrial, digital cable or digital satellite. The latter two options were rejected; cable, it is believed, because of the expense and satellite for a range of reasons, including the difficulty of providing the universal service that broadcasting legislation requires of RTE.

Satellite digital has other problems. Other than the very real problem that the satellite would probably be owned by an interest outside the State, a satellite "footprint" is so wide that RTE and TV3 might end up paying European rights, rather than the considerably lower Irish rights, for programmes acquired in the United States.

Even though terrestrial digital television offers the least number of channels, Mr Branagan has argued at several media conferences that it is the most suitable for Ireland because of our size.

He has made the point that, even where there are many channels available, such as in the United States, over 75 per cent of viewers stick with the four main networks.

There is an increasing urgency about the move towards digital television now that Britain has committed itself to terrestrial digital services on air by next year.

Mr Rupert Murdoch's digital plans have been set back quite significantly in recent weeks. He was forced out of the consortium awarded the commercial digital TV licence by the regulator, and there have been delays in launching his Astra 2 satellite, on which he planned to carry his proposed 200 satellite channels.

It now appears he will be hard pressed if he plans to beat the British terrestrial digital channels on air. Given that he is committed to offering a number of his channels, especially sport and film channels, to the new terrestrial services, it is difficult to see what he will offer that will not be available in a cheaper form.

If the Government accepts the arguments that were put to the RTE authority yesterday, it will deal with one political problem. Deflectors will be redundant and have no place in the new environment.

It does pose a problem for cable companies, however, as it is difficult to see what they can offer that will be cheaper than the £75 a year for 15 channels that was suggested to the RTE authority.