Is there a way to broadcast UDP packets with ESP8266 without wifi connection?

Question

My question is regarding an ESP8266 board and the ESP-touch technology.

ESP-touch uses the length field of a UDP package to broadcast wifi ID and PW through a device (like a smartphone) to the chip (like in my case ESP 8266).

I want to turn this around, more specifically: I want the ESP8266 chip to broadcast UDP packets with some sort of identifier-number in the length field of the UDP packet, without beeing connected to any wifi connection. Then these UDP packets are recieved by an app on a smartphone so the identifier-number can be extracted and used on the smartphone.

I am relatively new to this topic and do not know if this can work.

When I try to find any information online they all say that the first step is to connect the chip to a wifi. But I don't want that. The smartphone and the chip don't know each other and are not connected in any way. So I want this type of "broadcasting" so that the smartphone can recieve the package without really beeing connected to the chip.

I guess there must be some way to make it function like I explained above, but I can't find a way how this can work.

I don't need the chip to send UDP packets explicitely, it can be any type of package. I took UDP packet as an example because there is already the ESP-touch technology which is more or less similar.

The important thing is that the package that I send has a field where I can put some identifier-number in (not encrypted), which can then be recieved by another device like a smartphone where this identifier-number is extracted.

For clarification: I don't need to use ESP touch or anything related to that. I only stated this technology as an example. I just want to achieve the behavior stated above and in the picture! :)

This is an example picture how I want it to work:

Answer 1

No, it's not possible to send any packages without being connected to the network. ESP-touch or TI Smart Config or similar technologies utilize Monitor mode. As the name suggests, in this mode one can listen for packages, but can't send them.