Power Budget for Wide Area Ambient Backscattering Communications

The objective of this article is to extend the range of Ambient Backscattering Communications (ABC). The ABC technology is a key enabling technologies for Internet of Things (IoT) wireless communications. A rural open area towards Hanko, Finland is considered for the power budget calculations. FM radio waves are considered as the source of ambient RF waves as the FM radio waves have long communication range and the technology is readily available worldwide. The sensors are placed on a highway at an example distance of 30 km from the FM transmitter. There is a clear line of sight (LOS) connection between the FM transmitter and the sensors. The path loss is determined based on the sensor locations and the losses at the sensor occur due to diffraction and scattering. A power budget is calculated based on these aforementioned key system parameters. It is observed that there is around 44 dB of power margin available after the signal from the FM transmitter is backscattered (at the sensor) and the losses in the system are accounted for. This indicates that the receiver module is able to detect the signal as it is above the minimum reception level threshold for the system. Therefore, the radio waves are able to propagate further after the signal is backscattered at the sensor(s) utilizing the available power margin. Thus, the range of communication can be extended to a wider area.