Wireless Display on Ubuntu 18.04

WiDi/Miracast for Linux projects seem to be abandoned (https://01.org/wds , for example). The only workaround is to set up a DLNA server on your Linux box. It is well explained at https://www.lg.com/ca_en/support/product-help/CT20098023-1348676620463-file-sharing-dlna .

EDIT: You will need to install minidlna and make sure it is running. The laptop and TV must be connected to the same LAN/WiFi network. New source, media-sharing, should appear in the list of available sources on the TV.

Smart TVs' wireless display modes are implementations of Miracast (or Wi-Fi Display) technology under different commercial names. Miracast standard comprises a sink (receiver, Smart TV in this case) and a source (trasmitter, ubuntu in this case).

In Ubuntu, you can install gnome-network-displays through means of Flatpak system, and better be on Ubuntu 21.04 cause it has several bugfixes and features relevant for Miracast. Note that gnome-network-displays is still considered "experimental" by its authors, but it's worth a try by now.