What does it take to connect tens of billions of devices?
Among other things, transmit power control is a lynchpin feature of IoT-scale connectivity.
Blogs don’t start much nerdier than that kind of claim. But, good reader, fear not, for you shall not be disappointed for we shall explain how it is that not every network can connect billions of IoT devices.
First some definitions and explanation are in order. Transmit power control is the ability of an endpoint to adjust how “loudly” it broadcasts its signal enabling only the closest access point (AP) or so to hear it. Perhaps you didn’t realize that when endpoints broadcast their signal it isn’t just a single AP that can hear it. Other APs hear it too. This has a few very important implications. Each AP can only handle so much capacity, or said otherwise, can only handle so many signals that they can take in at once. So the more signals from distant endpoints that are heard by a given AP the less capacity it has to serve the endpoints that it really should be concerned with. Transmit power control drastically reduces this wasted capacity.
Transmit power control solves all of this. As more endpoints are added and APs are added to serve them, the endpoints with transmit power control adjust their “volume” so that only those APs closest to them can hear them. Suddenly, adding new APs actually adds more capacity. YES. This kind of network can connect billions of IoT devices.