IEC 62980:2022 defines procedures for transferring power to non-powered IoT devices using the existing ISM band communication infrastructure and RF WPT and a protocol for a two-way, long-distance wireless network in which IoT devices and APs communicate using backscatter modulation of ISM-band signals. Three components are required for two-way, long-distance wireless communication using backscatter modulation of ISM-band signals:
• an STA that transmits wireless power and data packets to SSNs by forming ISM-band signal channels between HIE-APs,
• a battery-free SSN that changes the sensitivity of the channel signals received from the STA using backscatter modulation, and
• an HIE-AP that practically decodes the channel signals whose sensitivity was changed by the SSN.
In this document, the procedures for CW-type RF WPT using communication among these three components are specified based on application of the CSI or RSSI detection method of ISM-band communication.
This document proposes a convergence communication protocol than can deploy sensors, which can operate at low power (dozens of microwatts or less) without batteries, collect energy, and perform communication, to transmit power to SSNs using RF WPT based on parasitic communication. This method can be applied to application service areas such as domestic IoT, the micro-sensor industry, and industries related to environmental monitoring in the future.