The answer is your end devices only signal on meaningful change, whatever that may be, and stay quiet the rest of the time. How meaningful that change must be depends on how much bandwidth you have. When you get right down to it you can do a lot with a little in the industrial controls and remote monitoring space.

We get so used to overly verbose communications protocols and overly abstracted data structures and methods, it's refreshing once in a while to care about each bit!

Much more with compression specialized to your use case and clever packet design.