But if the data stream is same for 5 devices can they all recieve it
at the same time like standard FM?
If your antenna emits in all directions (as per a quarter wave monopole) then once the EM field is created, any receiving antenna can receive the signal from any direction and multiple receiving antennas can do this simultaneously. This is slightly complicated by the fact that two close by receive antennas can interact with each other and create problems.
However, if the distance between receive antennas is greater than a couple of wavelengths then you should be ok.
Analogy: think of several people in a room looking at an LED turning on and off. Only those stood behind or partially shadowed by someone else my be inhibited in their view. Light is EM waves so it’s a bit closer to the truth than most analogies.
Think about broadcast radio transmitters and how many listeners there are.
However, protocols might be the sting in the tail. If the broadcaster requires some form of acknowledge that “someone” has received the message, then multiple receivers all responding together will be a problem. This can be overcome of course, like most things.