Directv is getting ready to come out with streaming only service,
See this. They will offer data free streaming on their AT&T network, kind of like T-Mobile did with their "Binge on" deal. Things are moving fast. If you have a Directv account this is included. Right now I can stream my Directv channels data free. If you have a device that allows screen mirroring between your mobile device and your TV you can cast the picture to the TV. Works great. My Roku 3 will hookup with my Galaxy S5 for screen mirroring. Works great.