Thanks for your reply. As to the TV input, who cares whether the signal arrives via cable or via radio link? What I need is hardware at the laptop that converts the laptop display signal to an outgoing radio signal and hardware at the TV that converts the incoming radio signal to whatever form the TV requires for display. The question is: Does such hardware exist and where do I get it?
As to the PC, it does not have a router. I think it has a network adapter (Realtek) but not wireless. I wonder if the PC needs to be involved. Conceptually, it should be possible to provide a wireless link between the ISP port (which feeds the PC) and the laptop. Maybe a wireless router does this, I am not familiar with them. Would a laptop have the required hardware built in?