[LINK] US switch to dig TV - potential for Internet?

rchirgwin at ozemail.com.au rchirgwin at ozemail.com.au
Sat May 26 10:43:52 AEST 2007


Geez, Stil, get with the program. The whole purpose of all bandwidth is 
to allow "content producers" to stuff things down the pipe at "content 
consumers". All else is anarchy. What fool considers democratic use of 
spectrum when it can be sold to pigopolists for buckets of cash?

Well, I agree with you, actually. Shoving things down in one direction 
is not communication, because there's only one party.

Most TV spectrum is useless for the mooted applications, but technology 
doesn't ever seem to get much traction once visionaries get their hands 
on the theories of social science.

Let's imagine, say, a symmetrical channel using a vacated ABC channel at 
70 MHz, and let's ignore any question of bandwidth. From transmitter to 
receiver, those kinds of signals are not particularly directional; so 
unless you want to encrypt the channel, everybody in range can see what 
you download. In the upstream channel, the same problem occurs.

(For those who don't believe me, before you dismiss what I'm saying, do 
some reading. Find out how big an antenna you need to get reasonably 
directional behaviour from a 4-metre wavelength. You will need a damn 
big Pringle's can...).

At best, most vacated TV channels will be good for some kind of 
broadcast - a digital broadcast perhaps, or a data broadcast maybe, but 
a broadcast nonetheless.

Now. I haven't actually done much background reading on the relationship 
between channel width and data rates, so this is a "thought experiment". 
Please correct me, anyone with better clue.

If 10 Mbps symmetrical needs 20 MHz channels (ie, one bit per hertz), 
then *one* customer connection on a 70MHz carrier signal needs a channel 
from 60 MHz to 80 MHz; and per 100 MHz you have five channels. Even with 
oversubscription you get, say, 50 customers per 100 MHz.

Even if there were 500 customers per 100 MHz of spectrum, I doubt that 
the economics would work that well...

RC

Stilgherrian wrote:
> On 26/5/07 9:26 AM, "Jan Whitaker" <jwhit at janwhitaker.com> quotes an
> article3:
>   
>> This public "spectrum" has the
>> capacity to deliver high-speed Internet signals almost everywhere in
>> the country. [...]
>>
>> Yesterday, many members of the SavetheInternet.com Coalition came
>> forward with a proposal: Let's use these airwaves to make the
>> Internet more neutral, open and affordable for everyone.
>>     
>
> Provided, that is, your view of the Internet is still about some central
> "producers" of information, ideas and "content" sending it all one-way to a
> mass of "consumers" who passively absorb it, all identical.
>
> True communication is only possible when the bandwidth is equal in both
> directions, and unfettered. Everything else is propaganda. Discuss.
>
> Happy Saturday,
>
> Stil
>
>
>   



More information about the Link mailing list