Here is the situation. I want to cast directly to my chromecast using screen mirror without a wifi signal. Here is why. At work I have no Wifi just a cellphone signal. I also have a TV with HDMI ports. I want to screen mirror my phone to my chromecast directly. My cell service limits me to 15GB a month of hotspot data but I have unlimited streaming if its on my phone. I want to use the data from my phone and then "throw" aka "cast" it to the TV so it is bigger. There is no Wifi option and I really don't see a reason a screen mirror WITHOUT and wifi isn't possible. I don't have an option to plug in hdmi directly to my phone which is unfortunate because iPhones can and I am to the point where I'd rather get one so I can plug in my phone and screen mirror that way.