In my Digital Communication Lecture today with Jon Crowcroft he was talking about multicast in IP routing and how this can be used for something like IPTV.

I was then thinking about multicast using TV over the satellite network. Sky tv uses some sort of modulation for sending all the tv programmes data to everyone within a certain range (using a key in the subscription card to decode the images), however there is only one demodulator inside the box (per input signal). But you should only be limited by the number of decrypters you actually have because you could potentially duplicate the input signal and watch all 1000 channels at once by decrypting all channels at once using 1000 different de-modulators etc…

Jon said that Andrew Moore wanted to do such a thing in software so you could potentially record all the channels at once!

This could be useful to know for my project!