[opendtv] Re: TV Technology: FCC Video Report Finds Expansion of Broadcast Services

  • From: Craig Birkmaier <craig@xxxxxxxxx>
  • To: opendtv@xxxxxxxxxxxxx
  • Date: Thu, 25 Jul 2013 14:48:08 -0400

On Jul 25, 2013, at 12:12 PM, "Hughes, Gary" <Gary.Hughes@xxxxxxxxxx> wrote:

> "Switched Digital" in a HFC network uses the same technology as VOD. UDP 
> streams are pushed to edge QAM devices (neighborhood nodes) where they are 
> modulated onto QAM carriers reserved for VOD/SDV. The last mile is MPEG 
> transport over QAM. It uses IP over the MSO's fibre links, but is not really 
> "IP delivery"

I touched on this in my reply to Bert. The most important factor is having the 
bandwidth in the last mile to send SDV. I agree with Gary that the current 
cable system approach is just a step in the right direction, adding more 
bandwidth in the neighborhood nodes to support VOD/SDV streams to each home 
using the existing QAM modulation. At the same time they are delivering more 
downstream bandwidth via their IP broadband services. We tested the speed at a 
friends house yesterday afternoon 27 Mbps downstream / 4 Mbps upstream. The 
next logical step is to replace the bands using QAM with more IP bandwidth. 

The good and bad news in all of this is that they can upgrade as needed to meet 
marketplace demands, but will probably keep QAM for video services as they 
replace the analog bands to deliver more broadband bits. Once again, a major 
factor in all of this is the huge installed base of QAM STBs.


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