FPGA Central

Existing cable systems "blast" a HUGE amount of information over a very
wide bandwidth CONTINUOUSLY into every home. This delivery method seems
extremely wasteful in that any one home typically only utilizes one or
two channels (let's say, 6 MHz channels) at a time. This is perhaps only
1/100th of the bandwidth that is occupied.

In addition, many of those same homes obtain internet access through the
same cable, but at a rate that is tiny by comparison - typically around
5 Mb/s (downstream), which is perhaps 500 kHz of bandwidth on the cable.
This is 1/12th of ONE of the 100 video channels received.

WHAT IF...

What if the entire paradigm changed such that ALL video bandwidth
requirements were removed and a very substantial internet access
bandwidth provided instead, say, a rate of 100 Mb/s.

This would allow up to four high-definition channels (the current OTA
ATSC HDTV transport layer supports up to ~20 Mb/s maximum before channel
encoding) to be transported over the IP connection and STILL allow a
whopping 20 Mb/s for non-video related internet access (surfing the web,
email, etc.). These numbers were based on the presumption that no more
than 4 TVs in one household are operated at one time.

This aggregate datarate (100 Mb/s) would require less than 12 MHz of
bandwidth over the cable, or only two TV channels.

There are two potential problems I can see with this paradigm shift:

1. The bandwidth aggregates linearly as a function of number
households served, whereas the bandwidth of the current paradigm,
while large, is fixed. Thus even though any one household would
only utilize 12 MHz of BW, this bandwidth aggregates as more and
more households are merged in the upstream interfaces to the internet.
How this would play out with the current cable industry's architecture
of "head" units I can't say since I'm ignorant of that architecture.
The mitigating factor is that the starting BW (at the household) is
only 1/50th of what it is now.

2. Hollywood et al. would undoubtedly get more than a little nervous
with this delivery method and would undoubtedly want some
super-unbreakable encryption and format to protect their IP rights.

Anyway's, just an idea. What do youse' guys (and gals) think?
--
% Randy Yates % "So now it's getting late,
%% Fuquay-Varina, NC % and those who hesitate
%%% 919-577-9882 % got no one..."
%%%% <[email protected]> % 'Waterfall', *Face The Music*, ELO
http://www.digitalsignallabs.com

Randy Yates <[email protected]> writes:
> [...]
> There are two potential problems I can see with this paradigm shift:
>
> 1. The bandwidth aggregates linearly as a function of number
> households served, whereas the bandwidth of the current paradigm,
> while large, is fixed. Thus even though any one household would
> only utilize 12 MHz of BW, this bandwidth aggregates as more and
> more households are merged in the upstream interfaces to the internet.
> How this would play out with the current cable industry's architecture
> of "head" units I can't say since I'm ignorant of that architecture.
> The mitigating factor is that the starting BW (at the household) is
> only 1/50th of what it is now.

I should add that there could very well be methods to mitigate the
bandwidth problem. For example, one architecture might consist of a
server that sits at some point upstream that has as one ("output") port
the IP feed to/from the households, one ("input") port the general
internet connection, and another ("input") port a set of pre-encoded
program material/channels that the users can potentially select
from. These channels can be stored on the server and time-shifted to
service the various downstream requests in the timing demanded by the
users.

If that makes sense....
--
% Randy Yates % "Midnight, on the water...
%% Fuquay-Varina, NC % I saw... the ocean's daughter."
%%% 919-577-9882 % 'Can't Get It Out Of My Head'
%%%% <[email protected]> % *El Dorado*, Electric Light Orchestra
http://www.digitalsignallabs.com

On Jan 16, 10:16*am, Randy Yates <ya...@ieee.org> wrote:
> Randy Yates <ya...@ieee.org> writes:
> > [...]
> > There are two potential problems I can see with this paradigm shift:
>
> > * 1. The bandwidth aggregates linearly as a function of number
> > * households served, whereas the bandwidth of the current paradigm,
> > * while large, is fixed. Thus even though any one household would
> > * only utilize 12 MHz of BW, this bandwidth aggregates as more and
> > * more households are merged in the upstream interfaces to the internet.
> > * How this would play out with the current cable industry's architecture
> > * of "head" units I can't say since I'm ignorant of that architecture.
> > * The mitigating factor is that the starting BW (at the household) is
> > * only 1/50th of what it is now.
>
> I should add that there could very well be methods to mitigate the
> bandwidth problem. For example, one architecture might consist of a
> server that sits at some point upstream that has as one ("output") port
> the IP feed to/from the households, one ("input") port the general
> internet connection, and another ("input") port a set of pre-encoded
> program material/channels that the users can potentially select
> from. These channels can be stored on the server and time-shifted to
> service the various downstream requests in the timing demanded by the
> users.
>
> If that makes sense....
> --
> % *Randy Yates * * * * * * * * *% "Midnight, on the water...
> %% Fuquay-Varina, NC * * * * * *% *I saw... *the ocean's daughter."
> %%% 919-577-9882 * * * * * * * *% 'Can't Get It Out Of My Head'
> %%%% <ya...@ieee.org> * * * * * % *El Dorado*, Electric Light Orchestrahttp://www.digitalsignallabs.com

Randy,

The keywords to google are: "Switched Digital Video"

see also

http://en.wikipedia.org/wiki/Switched_video

Mark

Randy Yates wrote:
> Existing cable systems "blast" a HUGE amount of information over a very
> wide bandwidth CONTINUOUSLY into every home. This delivery method seems
> extremely wasteful in that any one home typically only utilizes one or
> two channels (let's say, 6 MHz channels) at a time. This is perhaps only
> 1/100th of the bandwidth that is occupied.

since the same signal goes to many houses, the allocated bandwidth *per
house* is probably less than what you call the occupied bandwidth. (I
would call it utilized bandwidth.)

> In addition, many of those same homes obtain internet access through the
> same cable, but at a rate that is tiny by comparison - typically around
> 5 Mb/s (downstream), which is perhaps 500 kHz of bandwidth on the cable.
> This is 1/12th of ONE of the 100 video channels received.

Since it is dedicated to one house only, it is (by your reckoning) five
times the occupied/utilized bandwidth.

> WHAT IF...
>
> What if the entire paradigm changed such that ALL video bandwidth
> requirements were removed and a very substantial internet access
> bandwidth provided instead, say, a rate of 100 Mb/s.
>
> This would allow up to four high-definition channels (the current OTA
> ATSC HDTV transport layer supports up to ~20 Mb/s maximum before channel
> encoding) to be transported over the IP connection and STILL allow a
> whopping 20 Mb/s for non-video related internet access (surfing the web,
> email, etc.). These numbers were based on the presumption that no more
> than 4 TVs in one household are operated at one time.

Any number of sets; no more than 4 TV channels.

> This aggregate datarate (100 Mb/s) would require less than 12 MHz of
> bandwidth over the cable, or only two TV channels.
>
> There are two potential problems I can see with this paradigm shift:
>
> 1. The bandwidth aggregates linearly as a function of number
> households served, whereas the bandwidth of the current paradigm,
> while large, is fixed. Thus even though any one household would
> only utilize 12 MHz of BW, this bandwidth aggregates as more and
> more households are merged in the upstream interfaces to the internet.
> How this would play out with the current cable industry's architecture
> of "head" units I can't say since I'm ignorant of that architecture.
> The mitigating factor is that the starting BW (at the household) is
> only 1/50th of what it is now.

The cable companies need far more than 50 drops to break even. They
could double the potential number by allowing only 2 TV channels per drop.

> 2. Hollywood et al. would undoubtedly get more than a little nervous
> with this delivery method and would undoubtedly want some
> super-unbreakable encryption and format to protect their IP rights.

Why more than now? I'm not into that enough to see why.

> Anyway's, just an idea. What do youse' guys (and gals) think?

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Mark <[email protected]> writes:

> On Jan 16, 10:16*am, Randy Yates <ya...@ieee.org> wrote:
>> Randy Yates <ya...@ieee.org> writes:
>> > [...]
>> > There are two potential problems I can see with this paradigm shift:
>>
>> > * 1. The bandwidth aggregates linearly as a function of number
>> > * households served, whereas the bandwidth of the current paradigm,
>> > * while large, is fixed. Thus even though any one household would
>> > * only utilize 12 MHz of BW, this bandwidth aggregates as more and
>> > * more households are merged in the upstream interfaces to the internet.
>> > * How this would play out with the current cable industry's architecture
>> > * of "head" units I can't say since I'm ignorant of that architecture.
>> > * The mitigating factor is that the starting BW (at the household) is
>> > * only 1/50th of what it is now.
>>
>> I should add that there could very well be methods to mitigate the
>> bandwidth problem. For example, one architecture might consist of a
>> server that sits at some point upstream that has as one ("output") port
>> the IP feed to/from the households, one ("input") port the general
>> internet connection, and another ("input") port a set of pre-encoded
>> program material/channels that the users can potentially select
>> from. These channels can be stored on the server and time-shifted to
>> service the various downstream requests in the timing demanded by the
>> users.
>>
>> If that makes sense....
>> --
>> % *Randy Yates * * * * * * * * *% "Midnight, on the water...
>> %% Fuquay-Varina, NC * * * * * *% *I saw... *the ocean's daughter."
>> %%% 919-577-9882 * * * * * * * *% 'Can't Get It Out Of My Head'
>> %%%% <ya...@ieee.org> * * * * * % *El Dorado*, Electric Light Orchestrahttp://www.digitalsignallabs.com
>
> Randy,
>
> The keywords to google are: "Switched Digital Video"
>
> see also
>
> http://en.wikipedia.org/wiki/Switched_video
>
> Mark

Mark,

Indeed. See "A Switch in Time: The Role of Switched Digital Video in
Easing the Looming Bandwidth Crisis in Cable" in the July 2008 issue of
IEEE Communications magazine.
--
% Randy Yates % "My Shangri-la has gone away, fading like
%% Fuquay-Varina, NC % the Beatles on 'Hey Jude'"
%%% 919-577-9882 %
%%%% <[email protected]> % 'Shangri-La', *A New World Record*, ELO
http://www.digitalsignallabs.com