WIfi ESP8266 sending data over the air in a specific channel

Hi all.

I'm trying to use wemos module (it is like arduino with an ESP8266 embedded) to send a message trough wifi over the air in a specific channel.

What am i talking about?

I need to receive messages in a ieee802.11 software defined radio module. In this module i can't establish a network, just listen a channel, and read whatever someone is sending.Think about it as a sniffer.

Then my idea is send bytes, for example a message, through the ESP8266.

What i need?

I need just to:

Initialize wifi on Arduino
Set a channel (i do it with channel 13, it is most times free)
Send data in that channel

I don't need to create a network or something like that, just send data over the air.

Further Info

In the software defined radio module i can assign it an IP address and a MAC. (They are arbitrary). Then i think i could ask Arduino for sending the data to that IP and give to ARduino, and IP with the same three first bytes.

Thanks in advance.

Best regards,