• Energy Research

Precision agriculture in rural areas often faces challenges in communication due to the limited availability, robustness and power-constrained devices of existing infrastructure. The Constrained Application Protocol (CoAP), particularly when it is run over the User Datagram Protocol (UDP) transport layer, offers a lightweight and efficient communication solution for resource-constrained environments prevalent in precision agriculture. Therefore, this work focuses on the implementation of CoAP over UDP to bypass modem firmware and rely on the Zephyr operating system, providing a more accessible and scalable communication model for energy-efficient precision agricultural systems. The CoAP over UDP protocol implementation results highlight the practical advantages of CoAP for energy efficiency and reduced latency, particularly in scenarios with limited connectivity or high packet loss conditions. In addition, byte overhead analysis reveals a substantial reduction in overhead with CoAP, especially in small payload scenarios.

International audience ; This letter investigates radio resource allocation forsimultaneous wireless information and power transfer between afull-duplex (FD) multiantenna access point (AP) and multiplehalf-duplex (HD) single-antenna energy harvesting (EH) userequipment devices (UEs). The EH model of an advanced multistagerectifier circuit design is derived and used for radio resourceallocation. To account for both downlink (DL) and uplink (UL)traffic for each of the HD UEs, alternating DL and UL communicationphases between two UE groups are considered. We usethe weighted minimum mean squared error approach to developan iterative algorithm to maximize the system sum rate, utilizingoptimal receive and transmit beamformers.