How to receive wifi signal as FM (without permissions and confirmations)?

Question

Android

Task: TV over WiFi for an unlimited number of clients.
The server needs to be raised to ARM, androids should accept it. (Later, maybe iOS-s)
As you probably understood, the signal should not be secure, it should not be necessary to send something to the server when broadcasting, the broadcast frequency for tuning to it can be found out separately.
It is clear that you can distort the source as you like, but you need to take it on ordinary phones / tablets.
Are there built-in tools in android to tune in to a certain frequency and receive a signal without any authorization? You may need root for this, which is undesirable.

Answer 1

Discover UDP Multicast.
Implementation example via wi-fi

Answer 2

The way you imagine it is not implemented via wifi, within the current standards (theoretically possible, see below).
The closest option is multicast, but it's still not one-way communication.
And not all smartphones and tablets support multicast at the hardware level, for example, most (not the latest models) mtk processors for mobile devices do not support multicast at the hardware level, especially HD. And the same HD multicast at the software level, not all processors are extended.
If you do it on multicast, then via wifi it will work poorly, not stable, with the client’s picture spilling, and will not work at all on some devices. This is due to the implementation of the udp protocol and the zoo of devices that do not support multicast.
The only available and cheap option, for better compatibility, is hls. But, here you need 2 mb / s per client (a separate stream for each device), that is, for a 100 mb / s router (access point), a maximum of 50 clients. At 1Gb / s - 500 clients, but here the question is whether the iron of the router (ordinary) will pull 500 clients (I think it will not pull out more than 200).
Let's dream further:
In theory, it is possible to do as you imagined it, but you need your own software and hardware platform. That is, your own transmitting equipment and your own receiving: Server part with the ability to distribute via one of the wifi frequencies (here you can already select any frequency), and a receiver like a small TV (which you will distribute to clients at the entrance). This will not work with smartphones or other mainstream devices. Well, the cost of such a system, together with development, will start at $ 3,000,000, although I may be mistaken, and only designing on paper will cost you this amount ...

Answer 3

Even with multicast, at least you need to make a Captive Portal, where instead of an authorization page, a page with a player configured for the desired stream will open. But you still have to connect to the network with handles, even if it is open.