Samsung’s DeX software allows you to connect certain recent Samsung phones and tablets to an external display and use them like desktop computers.
Soon you may be able to that without the need to run a cable from your phone.
Xda-developers discovered clues pointing to wireless DeX mode in the Samsung Tips app.

The “tip” isn’t one you can actually use at this point, and it may have been pushed to the app accidentally. But it says you can “use Samsung DeX on a TV without a cable. Start DeX from the quick panel and choose an available TV.”
While that’s not actually something you do can do right now, it sure looks like Samsung is working on wireless support for DeX. What’s less clear is whether the feature will ever see the light of day. There’s no way to know whether this is an in-development feature, or one that has been postponed or canceled (one explanation for it showing up in Samsung Tips could be that wireless DeX support was initially scheduled to have been available by now).
For now, if you want to use DeX with an external display, you’ll need a cable.
Since last year, you’ve also been able to use DeX with a PC or Mac by plugging your phone or tablet into a computer and running a companion app on your computer.
thats what I was thinking to develop 😛
I wonder what kind of dongle you’d need to have plugged into the monitor though.
It’s not for monitors, it’s for Smart TVs. Particularly those that can support Miracast, which evolved into WiDi, and further is now Chromecast.
If you plug a Chromecast into a monitor, you should be able to stream DeX onto it.
…these are probable, but nothing concrete until it becomes official (Note20 Ultra release? Android 11? S30 release?).
WiDi was one thing and Mircast another and they do-existed. They incorporated interoperability (most likely to avoid a format war). Chromecast is similar but also different. ESPECIALLY since miracast can do a direct (ad-hoc) device-device connection/network while Chromecast has to go over your home/office network. This means that 1) you can theoretically use miracast anywhere even if you don’t have access to a network/router and 2) it is potentially faster with less lag (and I can testify to this from personal experience as a serious factor on some networks)
Also, chromecast seems to require individual apps to support it but will use the receiving device’s full screen, while miracast will just mirror your phone’s screen even if it has to leave black bars to fit everything.
If samsung let(s) you launch DeX to launch on the phone’s own screen, it would be really easy to use it with anything that has a miracast dongle in it.