Setting up your own IPTV.


So I would really like to setup/create my own IPTV. And I have a few questions, maybe someone can help?
1) About the relay.
How are video streams relayed in online TV?
What technologies are used nowadays?
What are the benefits or disadvantages of satellite usage as the video source? Is it possible to retransmit video from NOT satellite without any lag or network bandwidth overusage?
2) How does the server interact with the TV video stream relay (or video mediator)?
3) Is it better (if possible) to deal directly with the channel which we want to transmit or it`s slightly easier to work with the mediator? What are requirements for work with the channel directly, with the mediator?
4) What do TV providers offer? What are the prices for the relay and how is it accumulated?
5) Is it affordable to use own CDN from the very beginning or it`s better to use existing CDNs? Is it really needed at all?