J-RoC: A Joint Routing and Charging scheme to prolong sensor network lifetime

Abstract

Abstract-The emerging wireless charging technology creates a controllable and perpetual energy source to provide wireless power over distance. Schemes have been proposed to make use of wireless charging to prolong the sensor network lifetime. Unfortunately, existing schemes only passively replenish sensors that are deficient in energy supply, and cannot fully leverage the strengths of this technology. To address the limitation, we propose J-RoC -a practical and efficient Joint Routing and Charging scheme. Through proactively guiding the routing activities in the network and delivering energy to where it is needed, J-RoC not only replenishes energy into the network but also effectively improves the network energy utilization, thus prolonging the network lifetime. To evaluate the performance of the J-RoC scheme, we conduct experiments in a small-scale testbed and simulations in large-scale networks. Evaluation results demonstrate that JRoC significantly elongates the network lifetime compared to existing wireless charging based schemes.

LB-MAC: A Lifetime-Balanced MAC Protocol for Sensor Networks

“…As many schemes have been proposed at other layers to balance nodal lifetime or nodal energy consumption, we plan to compare LB-MAC with these schemes and study the advantage and limitations of each approach. Based on the study, we will explore the feasibility and strategy of the balancing techniques through cross-layer integration with middle layer [23], routing layer [24] or services in other network layers. We will also extend LB-MAC by adding lifetime balancing support for broadcast or multicast data services.…”

Lifetime maximization for sensor networks with wireless energy transfer

“…(1), and Constraints (2d) and (2e) represent that the base station can transfer energy to at most one sensor node at each period due to the sharp beam, coherently with current technology [9], [11]. The problem is not trivial due to the binary constraints and the undetermined number of the variables, which depends on the unknown maximum lifetime, as well as due to the lack of an explicit analytical expression for the cost function.…”

“…Notice that the WET efficiency, i.e., the ratio of the energy received at a sensor node to the energy transmitted at the base station, is not high, the base station forms a single sharp beam to increase the harvested energy [11]. Thus, the base station transfers energy to a single sensor node during a time slot period [9]. After the energy transmission phase, all the sensor nodes, v i , i = 1, .…”

“…However, if the charging capability is not large enough, the solutions above may be not practical. In [9], a problem to maximize the network lifetime by determining the path of the vehicle has been considered. An algorithm that charges the node with the minimal nodal lifetime has been proposed.…”

“…Energy from the environment, such as solar [6], wind [7], and vibrations [8], can be harvested by sensor nodes to charge their batteries. Although such energy can be considered as infinite and environmental friendly, the harvesting of the ambient energy is normally unpredictable and uncontrollable [9]. This is a major limitation of energy harvesting.…”