alt Hacker NewsBluetooth is enough, theoretically, if they have an agreement with Amazon: https://en.wikipedia.org/wiki/Amazon_Sidewalk
And most TVs these days have Bluetooth.
ATSC 3.0 also specifies a dedicated long-range return channel with a range of many kilometers.
I wanted to write comment to the effect of "I don't have amazon devices hur hur", but then realized it does not have to be my device... Especially in an apartment building...
What next, ultrasound? IR?