The receiver needs to change the frequency in order to avoid collision of data. As all the the devices will be transmiting at the same time, I thought the best way is using different frequencies for each device and reconfigure the receiver on execution time.
Summarizing, I need some arduinos to send and receive data from/to the other arduinos in a short elapse of time. As the data I need to transmit is so short(about 1.5KB uncompressed) the best idea seemed to be ramdon access instead of developing a complicated protocol.
Thanks