Multi transmitter communication

I have started working on a project, and I need to have multi-arduino wireless communication.
one master receiver & 3 or 4 transmitting arduinos.

It would also really help if 2 sets like this could work in the same room without interfering each other.

I think I need some communication protocol so the master would assign time slots for the transmitters, but I can't find an existing library, and don't want to implement a complicated protocol.

Please help!

Hi, welcome to the forum.

What about the RadioHead library : RadioHead: RadioHead Packet Radio library for embedded microprocessors

Thanks for the quick answer!
This library seemst to be I was looking for.

I looked at the code samples, and can't seem to find any reference to the physical connection of the transmitter/receiver to the arduino.
It seems that both sides should have both transmitter and receiver, but can't find any more information

Most of the modules are transceivers. For example HopeRF transceivers. They have a chip that does the protocol.

The RH_ASK for the cheapest 433MHz/315MHz modules have a separate transmitter and receiver without any smart chip. You don't want those.

More hardware at the SparkFun wireless buying guide : Wireless Buying Guide - SparkFun Electronics

Cheap on Ebay : nrf24l01+ for sale | eBay

CC2500 and CC1101 modules on Ebay : cc transceiver module for sale | eBay

This thread might have useful info for you since it is about essentially the same thing: 4-Way Radio - Project Guidance - Arduino Forum