[LINK] ABC Politics - Was : NextG Wireless Stays Up As NBN Fibre Broadband Crashes

[Tom Koltai]

> -----Original Message-----
> From: Tom Worthington [mailto:tom.worthington at tomw.net.au] 
> Sent: Monday, 7 February 2011 10:13 AM
> To: Tom Koltai
> Cc: link at anu.edu.au
> Subject: Re: [LINK] FW: NextG Wireless Stays Up As NBN Fibre 
> Broadband Crashes
> 
> 
> Tom Koltai wrote Friday, 4 February 2011 12:37 PM
> 
> > The artefacts are possibly acoustic waves reaching the
> > ionosphere interfering with the uplink/downlink ...
> 
> No. The ABC TV picture showed a reporter in the foreground 
> and trees out 
> a window behind them. When the trees waved in the wind, the picture 
> broke up. When the trees stopped waving, the picture was 
> okay. The most 
> plausible reason for this was that when the trees waved, the image 
> compression algorithm had more data than it could cope with. The 
> solution I suggested to the ABC was: don't point the camera 
> at the window.
> 

Any idiot can point a High Definition (HD) Video Camera at a subject and
pipe the output via WiFi to a router which is then connected via 3G. 

Some questions we should ask:

What else in the room apart from the Sony Betacam was using the same
spectrum WiFi ?
What are the 3G interconnect speeds of the closest Cell tower? 
Are the Cell Towers backhaul links, Microwave, PRI's, FDDI (don't
laugh), Sonnet or Fibre?
If PRI's, (How many E1's are used for backhaul)? Are the E1's bonded ?
3G, Therefore, are in fact the backhaul interconnects T1's ? Are the
T1's bonded ?
Are there any other spectrum issues in that region ? E.G. 1900 Mhz
crosstalk ?
Unicast or Multicast ?

Did the ABC research any of these issues prior to allegedly using
Broadband or did they just "wing-it"?
 
OK, now that we understand some of the questions we can address your
response to my humourous and cynical analysis of the "ABC Cyclone
Pixelation" affair.

For normal outside Broadcast operations, Mpeg-2 VBR -v- Mpeg-1 CBR used
to be a choice that the man on the spot (local editor - sometimes the
soundman) determined depending on whether there was a lot of movement or
not.
The streaming speed of the two is also a consideration when deciding
which standard to use. If for example, I attempted to send HD quality
over a transponder that was only set-up in the eighties to handle VCD
quality Mpeg-1 then I would expect break-up in the signal.

Televised Cricket for example is something that we would all be familiar
with and remember the perfect Mpeg-1 picture until the camera followed
the ball rapidly at which time pixelation set in. But not on the Grass
(which was fairly static) but the fast moving faces of the crowd in the
stands.

> > However, I also believe that pixelation is a "special effect"
> > utilised by some mixers to produce the "affect" of "We are in 
> > a Cyclone affected area and here is the pixelation to prove 
> > it" mindset.  ...
> 
> No, this looked like the real thing to me. I doubt that any 
> TV channel would deliberately have the image of their 
> reporter's face obscured.
> 

As I stipulated above, pixelation is never on the static portion of the
image, it is usually on the rapidly moving part.
Had the pixelation in the ABC footage been on the trees (which is where
Mpeg-1 CBR pixelation occurs) then the viewers wouldn't have known there
was a cyclone with wildly flapping trees.

> > ... It could be that the ABC budget is VSAT uplink only...
> 
> More likely the ABC was doing what it said they were
> doing: using a broadband link for sending the report.

No they didn't. (I was making a joke about the VSAT) They may have sent
it via broadband, but before you respond, lets discuss that for a
moment.
TCP-IP is packet based Network. It sends a packet, and waits for the ACK
from the destination. If it receives an ACK, it sends the next packet.
If it doesn't receive an ACK it resends the same packet continuously
until the mandated time-out or it receives an ACK.

In other words, any format sent via TCP-IP and spooled at the other end
(or streamed multi-cast live) would arrive with no artefacts (especially
not pixelation of the static portion of the image) without technical
incompetency or artificial injection of CNN Newsworthy editing tricks.

Now lets see if we can find any way to pixelate a Mpeg-2 image over
technically sound and expertly set-up broadband (which I expect from an
organisation like the ABC).

Yep, if we took an HD ....TS file and streamed it down a shaped
connection of only 1.5 Mb then we would loose at lest 25% of the
content. (Mpeg-2 is at least 1800 Kbps - whereas Mpeg-1 is up to 1800
Kbps.) Any idiot knows that you cant squeeze Mpeg-2 into a T1 and it
only just squeezes into an E1 - at the bottom end of the scale - i.e.:
No fast panning scenes or you may get to 10.08 Mbit/s which obviously -
sustained - won't fit in any Broadband I know of in Australia (outside
of a Telstra PR lab).

So Tom, are you suggesting that the ABC is full of incompetent
Technicians that don't realise that you can't live stream HD via a 1.5
Mb (T1) Cell tower interconnect?

Because if you are, that in itself is almost as bad an indictment.

Live interview segments need special tricks like PiP or multiple screens
to forego the "we are really in a cyclone" artefacts.

E.g.: green screen at Standard definition with background window shots
spooled a few seconds earlier.  
Or, overlay streaming of the Mpeg-1 interviewer on a green screen
against the Mpeg-1 of the wall with the PiP of the Mpeg-2 Window picture
of the Trees. 
(I can do this on Sony Vegas on a single core XP machine.)  
Or splitting the HD into four separate streams and multicasting using
different IP numbers on separate carriers.

Tom we can ping pong this backwards and forwards till the cows come
home, if you insist, but as I was doing this back in 1994 for a
commercial TV station who chose Ausnet Services to deliver BBC
programming from the UK as an alternative to Satellite - I have the
anecdotes and empirical data to back up my rather cynical view of the
ABC's political Cyclone stunt.

The reality is, Our current Broadband networks can't handle HD
Television.  We need the NBN. That was the impression that broadcast
left on everyone's hippocampus.

Result:
Actual real Pixelation - MEH Fail
PR for the ongoing roll-out of the NBN - Pass, Distinction.

Therefore, on the question in every tech persons minds... Does the ABC
employ idiots? 
Nope.
But they do appear to have some right winged psychologists influencing
their programming and content delivery methods (;-/).

OR
--
They are low on Budget funds and are using broadband so as not have to
pay transponder fees. (On B3 that's $8,000 per 64 Kbit/s per month
[eighteen cents per minute] - approximate commercial rate [@ 10 Mbit/s =
$ 228.05 per minute])


References:
MBONE: Multicasting Tomorrow's Internet http://www.savetz.com/mbone/
A book about the multicasting backbone and the future of multimedia on
the Internet
Copyright 1996, 1998 by Kevin Savetz, Neil Randall, and Yves Lepage

Simplifying Headend Architectures
http://www.motorola.com/web/Business/Solutions/Industry
Solutions/Service Providers/Telcos/Digital Headend Solutions/MPEG-4
Encodiing for
Telcos/_Documents/staticfile/SP_SimplifyingHeadendArchitectures.pdf
Motorolla White Paper 2009