Re: Comcast and 8VSB

On Thu, 08 May 2008 23:50:05 -0400 RobertVA
<robert_c72athotmail@[EMAIL PROTECTED]
> wrote:
| Alan F wrote:
|> TheWebJunkie@[EMAIL PROTECTED]
 wrote:
|>> According to a supposedly knowledgeable member of their technical
staff,
|>> Comcast Cable -- at least Comcast Cable of South Florida -- is
planning
|>> on providing their local broadcast feeds in 8VSB instead of clear QAM
in
|>> order to make them compatible with generic digital-to-analog
converters.
|>> Can anyone here confirm this?
|> 
|>  Comcast has a knowledgeable member of a technical staff who answers
|> the phone?? Was this a service rep making a house call or CSR on the
|> phone? Semi-seriously, the first rule about dealing with cable
companies
|> CSRs is that if they had a in-depth technical understanding of the
|> system, they would be working in the back rooms or on the engineering
|> staff, not answering the phone.
|> 
|>  I have not read any re****ts that Comcast would provide local digital
|> stations in 8-VSB. QAM is more efficient for cable, provides more
|> bandwidth, and most new TVs have clear QAM tuners. Yes, Comcast could
|> provide locals in 8-VSB, but I don't know if the coupon eligible
|> converter boxes with work with cable channel frequencies (beyond
|> channels 2-13).
|> 
|>  Alan F
| 
| The coupon eligible converters are intended for OTA use, not cable.

So.

Switching them to QAM:
10 program streams per 6 MHz channel needs 2 channels.
18 channels of 6 MHz recovered means 54 overcompressed HD program streams.
The cost will include getting QAM boxes for all the basic customers.

Switching them to 8VSB:
5 program streams per 6 MHz channel needs 4 channels.
16 channels of 6 MHz recovered means 48 overcompressed HD program streams.
They just tell the customers to get a coupon, buy a CECB, send in the
receipt
and they will credit the difference on the next bill, making the CECB
free.

The difference is a loss of 6 possible HD program streams.  The savings in
not having to buy a bunch of expensive QAM boxes for basic tier customers
might well be worth those 6 HD program streams.

They only need to be sure the 4 8VSB channels are on standard OTA
frequencies
so the CECBs will work.  That would be easy enough to do since typically
at
least 4 basic analog channels will be there already.

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