On Mon, 17 May 2010 10:12:20 -0700, Darren New wrote:

> Jim Henderson wrote:
>> Small relative to the size of the Internet, sure.  Small relative to
>> the size of a given network, maybe not so much.
> 
> I meant small physically. Rarely does a broadcast network extend over
> more than (say) one building. Not if you're talking about a 2-way
> broadcast.

What do you mean by "2-way broadcast"?

> Maybe cable IP systems? I don't know how they work on the cable, whether
> it's closer to TDMA or closer to CDMA or what. Clearly it's not
> isochronous, so you get the bandwidth you ask for if it's available.
> Thinking on it, I'm guessing at least the cable network for the local
> neighborhood is probably one big broadcast tree, so yea, bigger than I
> was thinking.

Yes, but from a standpoint of multicast, there again, you get some 
savings (and increased scalability).  I imagine (but don't know for sure) 
that cable uses some sort of multicast scheme (though probably not 
multicast over IP) so there isn't a bottleneck at the transmitting end of 
things; all people who are watching channel 657 are likely part of a 
multicast group of some sort, otherwise you'd hit xmit bandwidth 
limitations when a large number of people start watching TV all at once.

Jim

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