Quality of Energy Provisioning for Wireless Power Transfer

Abstract

Abstract-One fundamental question for wireless power transfer technology is the energy provisioning problem, i.e., how to provide sufficient energy to mobile rechargeable nodes for their continuous operation. Most existing works overlooked the impacts of node speed and battery capacity. However, we find that if the constraints of node speed and battery capacity are considered, the continuous operation of nodes may never be guaranteed, which invalidates the traditional energy provisioning concept. In this paper, we propose a novel metric -Quality of Energy Provisioning (QoEP) -to characterize the expected portion of time that a node sustains normal operation by taking into account node speed and battery capacity. To avoid confining the analysis to a specific mobility model, we study spatial distribution instead. As there exist more than one mobility models corresponding to the same spatial distribution, and different mobility models typically lead to different QoEPs, we investigate upper and lower bounds of QoEP in 1D and 2D cases. We derive tight upper and lower bounds of QoEP for 1D case with single source, and tight lower bounds and loose upper bounds for general 1D and 2D cases with multiple sources. Finally, we perform extensive simulations to verify our theoretical findings.Index Terms-Quality of energy provisioning, wireless power transfer, mobility.

Efficient Wireless Charger Deployment for Wireless Rechargeable Sensor Networks

“…In this section, we review the research results [3][4][5][6][7][8][13][14][15][16][17] most related to our work. Kim et al [3] investigated various ambient energy-harvesting technologies using different power sources, such Energies 2016, 9, 696 3 of 22 as solar power, thermal power, piezoelectric power, and wireless RF power, in the aspect of their applicability for self-sustainable wireless sensor platforms.…”

“…η is the rectifier efficiency, L p is polarization loss, and β is a parameter to adjust the original Friis equation for short distance transmission. Dai et al [6] stated that if the constraints of sensor node speed and battery capacity are considered, the sustainable operation of sensor nodes may not be guaranteed. It proposed the concept of quality of energy provisioning (QoEP) to characterize the expected portion of time that a sensor node can sustain operation by taking into account node speed and battery capacity.…”

“…Liang et al [8] considered a scheduling problem similar to that addresses by Xu et al in [6]. The problem is how to use the minimum number of mobile chargers to charge sensor nodes so that none of sensor nodes runs out of energy, subject to the energy capacity of mobile chargers.…”

“…The replenishing is achieved by equipping every sensor node with an energy harvester to harvest energy from different sources [2,3], such as solar power, thermal power, radio frequency (RF) waves, or air flow, as shown in Figure 1. Many recent studies [4][5][6][7][8][9][10][11][12][13] focus on the WRSNs due to their sustainability. Some other studies [14][15][16][17][18][19][20] investigate battery-less or battery-free wireless sensor networks (WSNs) in which sensor nodes are powered by capacitors storing energy harvested through wireless power transmission (WPT), especially microwave power transmission (MPT).…”

Adaptive Transmission Range Based Topology Control Scheme for Fast and Reliable Data Collection

“…Topology control technology brings benefits to the network. (1) Reducing the energy consumption of nodes [10][11][12][13][14]: in wireless sensor networks, the density of communication devices is usually large [15]. When communication between devices to devices (D2D) is required, the transmission power can be adaptively adjusted according to the distance between devices (or nodes).…”