Particularly with low-end RF hardware, since that will probably respond to the RF noise generated whenever the elevator in the next building, or the washing machine in the next house, or even the furnace or air conditioner starts up.

Low-cost RF hardware can be helped a little with sophisticated protocols, but most of the effort is used in protecting the system from the low-cost RF hardware.

Bit rates are low because the low-cost RF hardware is not very well filtered and not very fast to respond to signal changes. It's full of compromises, each introduced to favor cost. It works fine for remote controlled toys or even automobile door locks and alarm systems wherein a lot is know about the individual setup.

What the O/P clearly wanted is the performance of a $100/station RF link for the $3 or so that he's willing to spend.

Erik assumes he can support a high bit rate ... and even that won't work well, and he assumes things he just won't be able to do with a cheap RF link.

I'm seriously interested in low-power (short-range, not energy-saving, though that's a goal, too) RF hardware for controlling a home environment by doing such things as disabling the lighting when the room is empty, and suppressing the heating and closing the door when a room is empty. I'd like to be able to do that for an average of $20 per function, but that means that the hardware has to cost $5 or less per station. Since there sometimes are motors and pulleys involved, that will be difficult.

I've had to deal with precisely this problem, since every room will have a thermostat and a people-counter, but there are other functions that have to have support and, therefore, communication with the system master, and the system master has to "know" "who and what" every one of them is.

It has to be cheaper than commercial "over-the-power-line" communication hardware.

RE