I did a bit of research, and here is what I learned so far.
I do not need an arduino to send or receive the signal. I should be able to use/program just a microchip and add few components.
I believe I should be able to decide to use arduino to send signal if needed and not use arduino to receive it.
This tutorial is super interesting
http://narobo.com/articles/rfmodules.html
and so is this one
http://winavr.scienceprog.com/example-avr-projects/running-tx433-and-rx433-rf-modules-with-avr-microcontrollers.html
Ideally I have multiple receivers with a unique id each. And a way to register each receiver against the central unit that send out the signals.
I wonder if I can directly buy programmable RF modules instead of designing new ones?
For instance, would something like this solve my problem? (although is a bit expensive)
At the end of the day what I have to do with the signal I receive should be pretty simple (something like change the intensity of a bulb light)
Suggestions?