[BC] Rich Wood, you weren't there for those discussions

[Barry McLarnon]

On Tuesday 02 February 2010 09:17:27 Edwin Bukont wrote:
> Rich
> 
> and a request to Barry to please remove this idiot

If I were the Barry in question, I know which idiot I'd be tempted to give 
the boot to...

> Since my involvement in this digital business goes back to 1991, I can
>  speak.  The published power level expectations for digital facilities go
>  back to at least 1998.  No manufactuer can claim any ignorance of the
>  -10dBc future.  The -20dBc level has been sort of a holy grail for the
>  IBOC approach in the interest of maintaining the capture ratio as a
>  method to reduce interference between analog and digital.  However, going
>  back to at least 2001, it has been no secret that the digital carrier
>  power would have to come up to -10dB for full pattern replication. 
>  However, the cost and complexity to go full bore at analog TPO plus -10dB
>  while trying to make it all work in the field was concerned bad on many
>  fronts.  You don't experiment at full power.  If you had any technical
>  sense at all, you would understand how properly this has been handled in
>  both scientific and engineering terms of best practices.

Absolute nonsense.  I've seen a number of attempts to rewrite history on this 
list, but this one takes the cake.

What "discussions", pray tell, did you take part in?  I've worked in digital 
radio broadcasting research for more than thirty years, and during that time, 
I've followed IBOC developments very closely - more closely, perhaps, than 
anyone else who wasn't directly involved in its development.  Back in the 
last millennium, I was involved in NRSC committee work related to DAB system 
evaluation, and I was a member of the task group that developed the 
procedures for testing these systems in simulated multipath channels.  I've 
read all of the relevant reports and meeting minutes that emanated from the 
NRSC, all of the technical papers and test reports issued by iBiquity and its 
predecessors, and all of the reports, evaluations and other filings on FCC 
Docket 99-325.  I've written numerous articles and technical reports on the 
subject of IBOC, and developed methodology for testing IBOC systems and 
predicting their coverage and impact on analog reception.  All this may sound 
like an unhealthy obsession, but in fact it was part of my job, initially as 
a researcher in a Canadian government lab, and later as a contract 
consultant.  In all of my studies, not once have I seen the name "Ed Bukont" 
come up as being part of any "discussions".  More importantly, prior to 
around 2005 or 2006, I saw no hint of any anticipated need or plan to 
increase the digital power level of FM IBOC (other than the obvious one 
involved in someday transitioning to an all-digital system).

The question of the optimum digital power level for hybrid IBOC was 
investigated quite extensively back in the 90's, and it was determined that 
setting it higher than about -20 dBc would be overly detrimental to analog 
reception, both for the host station and its adjacent channel neighbors.  In 
the system description that iBiquity provided to the ITU in 2001, the power 
level was in fact pegged at -22 dBc, but they edged that up to -20 dBc for 
the tests and evaluation whose results were submitted to the FCC.  And, as 
Jonathan Hardis has already pointed out, a basic cornerstone of those results 
was the claim that field results demonstrated reliable digital coverage out 
to 45-50 dBu contours.  There was nothing in those reports stating that the 
power level might have to be revisited at some future date.

The game changer came in 2004, when NPR's Tomorrow Radio project demonstrated 
that the 96 kb/s payload could be split into multiple audio streams.  By this 
time, it was already evident that the general public had no interest in a new 
digital radio system that simply duplicated existing analog audio broadcasts 
- this was clearly demonstrated not just in the US, but also in Canada and 
other parts of the world.  The only place that DAB was gaining some traction 
was in the UK, where the service was being used for new programming that was 
not otherwise available (over the air, at least).  Ibiquity and their backers 
jumped on this new feature as a way of snapping IBOC out of its doldrums.  As 
those new HD2/HD3 streams rolled out, however, the fly in the ointment became 
evident: dropouts.  The dropouts that were papered over by blend to analog in 
the primary audio stream were annoying muting events in the secondary 
streams.  Car manufacturers are particularly leery of such things, since they 
lead to unhappy customers and returned vehicles.  Without the major car 
manufacturers on board to install IBOC-capable receivers at the factory, the 
rollout was pretty much doomed.  Shortcomings in indoor reception were a 
concern too, of course.  So, the idea of a power hike was hatched, and later 
sprung upon an unsuspecting industry (not to mention the public, who 
apparently have no say at all in these matters).

Oh, and I enjoyed your comment about "maintaining capture ratio".  Sounds 
very erudite and technical, but apparently you missed the posting from Dave 
Hershberger a few days ago, or you would know that capture ratio is really 
not a factor in protecting FM from wideband digital interference such as 
IBOC.

> Using -20dBc has proven that the technology works, in a technical sense. 
>  It is necessary to get to -10dBc to make it work in a financially viable
>  sense where pattern replication and 50/50 service contours are
>  sustainable.

Yup, uh-uh... and the cognoscenti knew it all from the start.  Nothing to do 
with a fundamentally flawed design, and a change in direction after the 
system was already approved and deployed.

> I am really sick of your ignorant diatribes.

Pot, meet kettle.

> I want you off this list and
>  wish Ibiquity would sue you for damage to their business.  Or perhaps
>  your misinformed clients should sue you.

No doubt IBOC has been lucrative for you, and you're keen to defend that 
vested interest, but really, this is way over the top.

Now that I've quoted it, I guess Rich will now see your original posting - my 
apologies to him for that.

Barry

-- 
Barry McLarnon VE3JF  Ottawa, ON