I have a harmony hub that can control the tv, fios, av receiver etc. It repalced a harmony remote that I had that controled everything. I can say Alex turn on the TV, Alex tell harmony pause, Alex tell harmony increase volume, Alex tell harmony skip ahead (30 second skip on dvr)
I believe is can change channels too, but have not set that up yet. The hub cost about $100 from Best Buy, and you will need a lot of set up work to define your equipment as well as the Harmony app amd the Echo Harmony skill enabled.
Logitech Harmony Hub is indeed the answer. As the other poster mentions you can control number functions including switch to different inputs and channels (you have to setup favorites and then say things like "Alexa, turn on NBC".
In order to keep discussion on the community current, this topic has been locked to prevent new replies. If you have a similar question or issue that you wish to discuss, then please feel free to post a new message on the most relevant board. Thanks!