Jim Henderson wrote:
> On Mon, 17 May 2010 12:15:13 -0700, Darren New wrote:
> 
>> Jim Henderson wrote:
>>> What do you mean by "2-way broadcast"?
>> Well, FM radio would be a one-way broadcast. Coax ethernet would be a
>> two-way broadcast.
> 
> OIC what you're saying, that the filtering is applied by the receiving 
> end (either filtered by software or hardware).

Right.

>> Well, look, there really isn't something that's a multicast physical
>> layer. 
> 
> Maybe Sirius radio?  Dunno, you might be right on that.

Different frequencies, sure. I'd more likely call that lots of independent 
networks.

> Would have to find someone who works for a cableco to confirm, 
> obviously.  (Or a good article describing the technology)

Yeah.

>>> all people who are watching channel 657 are likely part of a multicast
>>> group of some sort,
>> Sure. And all people watching channel 657 are also receiving channel
>> 652. They're just not tuning it. Just like FM radio.  (And I was talking
>> about IP over cable, actually, not TV per se. :-)
> 
> That implies a pretty enormous total bandwidth on the coax cable coming 
> into your house, then.  If you figure 40 SD channels and 40 HD channels, 
> for example, that several megabits of digital broadcast being sent out to 
> be filtered.

Yep. A cable can carry huge amounts of data, depending on its length. The 
closer the fiber hubs out to the houses, the more channels you can carry.

> I was using cable TV as an example because it's data being sent over a 
> network.  Data is data is data is data, after all. :-)

Exactly.

-- 
Darren New, San Diego CA, USA (PST)
    Ada - the programming language trying to avoid
    you literally shooting yourself in the foot.

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