Here we go again.

Industry memories are conveniently short, so history is easily rewritten. So it helps to get facts on the record for future reference.

When the BBC and Freeview first started to experiment with HD transmissions from Crystal Palace in 2006, hobbyists found they could use PCs to pick up the signals. Enterprising companies offered kit for sale.

Wise tech-virgins inside the BBC worried that consumers were at risk of being conned and offered to hold briefings for the technical press. We were asked to pass on the warning that although Freeview HD would use MPEG-4 compression (instead of Freeview's current MPEG-2), the Freeview DVB transmission system might be changed to the more efficient DVB-T2 standard. This would make all DVB-T/MPEG-4 HD gear obsolete.

France moved fast into HD by adopting DVB-T/MPEG-4 but, with encouragement from Ofcom, the UK planned longer term for MPEG-4 and T2.

So the hobbyist HD kit is, as predicted, now obsolete - unless perhaps used in France.

The UK will be the first country in the world to launch MPEG-4/T2. The chips needed for T2 receivers are only just hatching. There are no finished receivers. No one knows for sure how the T2 chips will work in domestic receivers with real-world aerials until they start to be used in real homes.

But Freeview blithely swept all doubts under the carpet, confidently promising: "Freeview HD receivers (set-top boxes, digital television recorders and integrated televisions) will be available from early 2010 and HD services on Freeview will be available to 50 per cent of the population in time for next June's World Cup, and to 98.5 per cent* of the population by the end of digital switchover in three years' time... Viewers in London, Glasgow, Newcastle, Leeds, Bradford and Birmingham should receive signals by the end of March 2010."

A puffy press release quoted Caroline Thomson, the BBC's chief operating officer, as saying: "This is a terrific step forward." And Ilse Howling, Freeview's managing director, enthused: "This is great news for the millions of Freeview viewers who are looking forward to getting high definition with no subscription next year."

On December 2, a curious mix of a few tech and lifestyle journalists were invited to the BBC's Television Centre and shown some HD pictures from lab gear, hit with a Powerpoint presentation and then ushered out before there was a chance to ask serious questions - because the room was needed for more important people and Freeview had to admit there were no receivers anyway.

Once again, and despite previous promises to communicate more usefully, Freeview's PR people had failed to communicate, explaining later and only when asked: "We couldn't accommodate everyone, but I have been passed the presentations, which I'm happy to share with you."

The Powerpoint presentations was short on hard facts, except that "DVB-T2 with MPEG-4 allows up to four HD services to be supported on Freeview HD" with a variable bit rate of between 3-17Mbps for video and 320kbps for 5.1 surround and 128kbps for stereo.

Most significantly, the time line shows receiver development continuing all through 2010. So how does this fit with a March 2010 launch?

Your guess is as good as mine, because of course I wasn't invited, so I didn't get the chance to ask the question on dealers' behalf. Which is perhaps why Freeview "couldn't accommodate" me.

It is already starting to backfire, with dubious adverts for Freeview HD gear already appearing and the wise tech-virgins inside the BBC now starting to worry all over again.

Barry Fox