Efficient Green Energy Far-Field Wireless Charging for Internet of Things

Sustainable RF Wireless Energy Transfer for Massive IoT: Enablers and Challenges

“…Scope Enablers Sustainability dimension economy equity environment [4] Efficient WET PBs' deployment, efficient beamforming, enhanced RF-EH designs ✓ ✓ [10] Massive WET PBs' (devices') architecture & deployment, programmable medium, ✓ ✓ resource scheduling, distributed ledger technology [19] Security Blockchain, contract theory, lightweight consensus protocol ✓ [13] Green IoT Ambient EH, WET, wired energy trading ✓ [12] Green WET Ambient EH, green PBs deployment ✓ ✓ [14] Green WET Green PBs deployment, millimeter wave communications ✓ [17] Efficient WET Concurrent ambient EH and WET to charge IoT devices ✓ [15] Green WET Green PBs deployment, dynamic PBs-to-IoT devices association ✓ ✓ [5] Efficient WET Directional antennas, dynamic PBs-to-IoT devices association ✓ [7] Efficient WET Trajectory planning of mobile PB ✓ ✓ [8] Efficient WET Trajectory planning of mobile PB, directional antennas ✓ ✓ [6] Efficient WET Optimal deployment of PBs, directional antennas ✓ ✓ [9] Efficient WET Trajectory optimization of a flying PB, intelligent reflective surface ✓ ✓ [16] Green WET Distributed green energy storage, nomadic WET ✓ ✓ [18] High-power WET Low-power PBs, EMF-compliant strategies, near-field RF charging ✓ ✓ This work Sustainable WET Green WET, secure energy transactions, gPBs's flexible deployment, ✓ ✓ ✓ minimize the overall expenses, ubiquitous charging with minimum RF pollution illustrate this, in Fig. 2a we compare the overall costs of WET-enabled IoT deployments, including grid-powered PBs, battery-powered PBs, gPBs, and the baseline scenario where the devices rely solely on their batteries.…”

“…Regardless of the implementation, flexible antennas provide the tools for overcoming the channel impairments by dynamically reconfiguring the radiator. Furthermore, the integration of renewable sources into WET-enabled networks has been also proposed in the literature either to support the operation of the PBs [10], [12]- [16] or to aid the WET service for reducing PBs' energy consumption [17]. Specifically, [12] studies the optimal charging scheduling strategy of a network of PB powered by renewable sources to maximize the number of charged devices in a round, [13] focuses on the integration of ambient EH and WET, and [14] discusses the main features, requirements, and enabling technologies for greening WET-enabled networks.…”

“…Furthermore, the integration of renewable sources into WET-enabled networks has been also proposed in the literature either to support the operation of the PBs [10], [12]- [16] or to aid the WET service for reducing PBs' energy consumption [17]. Specifically, [12] studies the optimal charging scheduling strategy of a network of PB powered by renewable sources to maximize the number of charged devices in a round, [13] focuses on the integration of ambient EH and WET, and [14] discusses the main features, requirements, and enabling technologies for greening WET-enabled networks. Moreover, [16] propose a WETenabled architecture for realizing sustainable smart agriculture applications, and [10] discusses variants for integrating renewable energy to power PBs.…”

On the Optimal Deployment of Power Beacons for Massive Wireless Energy Transfer

“…The full disconnection of WET from the fuelbased grid not only has a positive impact on the [4] Efficient WET PBs' deployment, efficient beamforming, enhanced RF-EH designs X X [10] Massive WET PBs' (devices') architecture & deployment, programmable medium, X X resource scheduling, distributed ledger technology [17] Security Blockchain, contract theory, lightweight consensus protocol X [11] Green IoT Ambient EH, WET, wired energy trading X [12] Green WET Ambient EH, green PBs deployment X X [13] Green WET Green PBs deployment, millimeter wave communications X [16] Efficient WET Concurrent ambient EH and WET to charge IoT devices X [14] Green WET Green PBs deployment, dynamic PBs-to-IoT devices association X X [5] Efficient WET Directional antennas, dynamic PBs-to-IoT devices association X [7] Efficient WET Trajectory planning of mobile PB X X [8] Efficient WET Trajectory planning of mobile PB, directional antennas X X [6] Efficient WET Optimal deployment of PBs, directional antennas X X [9] Efficient WET Trajectory optimization of a flying PB, intelligent reflective surface X X [15] Green WET Distributed green energy storage, nomadic WET X X This work Sustainable WET Green WET, secure energy transactions, gPBs's flexible deployment, X X X minimize the overall expenses, ubiquitous charging with minimum RF pollution environment but also encourages the use of selfsufficient PBs which can provide a ubiquitous charging service, as we discuss next.…”

Joint Optimization on Trajectory, Data Relay, and Wireless Power Transfer in UAV-Based Environmental Monitoring System

“…However, this approach comes with a notable drawback as it significantly escalates the deployment costs. To mitigate this problem, a number of works (e.g., directional antenna transmission [7], scheduling [8,9], and energy waveform optimization [10,11]) have been investigated in the literature. One of the most promising solutions is introducing unmanned aerial vehicles (UAVs) [12][13][14][15][16][17][18][19][20][21] as intermediate nodes to collect data and/or transfer energy, because UAVs can achieve flexibly shorter distance and line-of-sight (LoS) links thanks to their mobility.…”