Reconfigurable Intelligent Surface-Assisted Routing for Power-Constrained IoT Networks

In power-constrained wireless networks, extending network lifespan can be achieved through effective energy harvesting techniques. Developing energy-efficient routing protocols in such networks is complex due to the unstable and unpredictable harvested energy. In this regard, reconfigurable Intelligent Surfaces (RIS), capable of manipulating the RF signals, offer enhanced energy harvesting, which in turn minimizes the nodes' battery recharging time (BRT). Our study presents a novel RIS-assisted routing protocol for multi-hop energy harvesting-based wireless networks. The protocol assigns channels to each hop on the chosen path. It incorporates a rate calculation algorithm that takes into consideration the harvested power, BRT, and channel conditions. More specifically, it assigns a specific rate to every available channel, taking into account the energy available at each node, the estimated time required for battery recharging, and the link status between nodes. By selecting the highest rate per hop, the protocol enhances network throughput while considering energy limits and channel quality. The proposed approach is evaluated and compared with the benchmark, the Min hop scheme, using MATLAB simulations, demonstrating its superior performance.