I don't quite understand how they are generating the packets from the passive device, but it sounds as though it basically makes a low power packet generator (e.g., a sensor sending an MQTT packet) possible without using any significant power over what the sensor itself needs. It apparently works with existing devices on the receiving end, but I'm not clear what needs to happen to make new devices that are ultra low power. Or, does it simply take a software update to the existing device to utilize the new scheme.
Either way, interesting topic.