[preppyboy18]

I think it would be cool if television didn't have certain time slots for shows. I think it would be neat to be able to sort of rewind days, weeks, months or years of television shows and go back to an episode or favorite show and rewatch it. Many times there isn't anything on tv that people want to watch and this would guarantee that you could! For example, if I wanted to rewind to an episode of my favorite soap from a month ago or year ago, I would be able to.

Reward: I would want this service given to me for free for the rest of my life.

[Steve]

Actually this is a pretty commonsensive idea, and I wonder why it hasn't been done yet. Does anyone know? Is the technical side really so difficult? Or is the main obstacle sticking in the commercials?

[jamiefay]

I mean this in the nicest way... but have you heard of TiVo?

[kamlem]

That's not quite how TiVo works. You need to have taped the show previously in order to go back and watch it You can't just go back and watch anything you want.

[kessmann1]

One of the biggest obstacles is the amount of bandwidth required.
Take the case of a single user wanting to watch a program that was
on Channel 2 two days ago. First, the TV station which carried the
older show cannot transmit the show to this single user on Channel
2. If the station did, the current broadcast to all other users would be 'walked on'. Using a channel of another station would not work for the same reason. Some currently unused frequency would be required.

Now expand the scenario to the case of two users simultaneously wanting to view two different past shows at two different times from
different networks. Each station would need to transmit the old shows on some currently unused frequency for the reasons given
above. Furthermore, the two unused frequencies must not be the
same or each of the speacial users telecasts would 'walk' on each
other.

Carrying on, it can be seen that each speacial user must have his
own private channel in the currently unused frequency spectrum.
Given that each video channel is a minimum of 6 MHz wide and that
there are over 300 million potential users of this service in the US
alone leads to the conclusion that the airwaves will be come totaly
saturated very quickly.

One way to reduce the number of airwave channels required is to go
to a form of cable - either Coax or Fiberglass. In theory, cable systems are closed from the outside world.

In this case, each special user will be required to have his own
dedicated cable over which he can receive his special telecasts.
However, each dedicated closed cable could use the same frequency
as the other cables. Only the programming on each cable will be
different as selected by the users. Note that each of the dedicated
cables will have to extend to each television broadcasting station the
user whishes to view. This approach reduces the airwave bandwidth
requirements at the expense of installing one heck of a lot of cable.