Duty Cycle Of Sensor Nodes Research Articles

Energy efficient analysis with end-to-end delay constraints in wireless sensor networks

Longer time sleep (low duty cycle) of sensor nodes with sleep-wake mechanism in wireless sensor networks will result in longer delay for transmitting of data-collected, although it can reduce node's energy consumption and extend node's lifetime. Therefore, it is an important and significant topic to balance energy consumption and delay in wireless sensor networks. In this paper, we mainly focus on energy efficient mechanism with end-to-end delay constraints. We divide input flows into multiple sub-flows in terms of a configurable weight of links in order to avoid excessive energy consumption of sensor nodes caused by forwarding too much data-collected. So, data-collected pass through multiple different links and sensor nodes to reach the sink node. We establish an analytic framework for end-to-end delay based on network calculus according to arrival process of flows and service process of sensor nodes. On the other hand, sensor nodes provide rate-latency guaranteed service for arrival flow based on their active time and the maximum capacity of links. The case study and numerical results show that the proposed method can provide an effectively balanced strategy between energy consumption and delay by adjusting the duty cycle of sensor nodes properly in wireless sensor networks.

Energy adaptive MAC for wireless sensor networks with RF energy transfer: algorithm, analysis, and implementation

Radio frequency energy transfer (RET) has been proposed as a promising solution to power sensor nodes in wireless sensor networks (WSNs). However, RET has a significant drawback to be directly applied to WSNs, i.e., unfairness in the achieved throughput among sensor nodes due to the difference of their energy harvesting rates that strongly depend on the distance between the energy emitting node and the energy harvesting nodes. The unfairness problem should be properly taken into account to mitigate the drawback caused from the features of RET. To resolve this issue, in this paper, we propose a medium access control (MAC) protocol for WSNs based on RET with two distinguishing features: energy adaptive (EA) duty cycle management that adaptively manages the duty cycle of sensor nodes according to their energy harvesting rates and EA contention algorithm that adaptively manages contentions among sensor nodes considering fairness. Through analysis and simulation, we show that our MAC protocol works well under the RET environment. Finally, to show the feasibility of WSNs with RET, we test our MAC protocol with a prototype system in a real environment.

An energy‐efficient asynchronous wake‐up scheme for underwater acoustic sensor networks

AbstractIn addition to the requirements of the terrestrial sensor network where performance metrics such as throughput and packet delivery delay are often emphasized, energy efficiency becomes an even more significant and challenging issue in underwater acoustic sensor networks, especially when long‐term deployment is required. In this paper, we tackle the problem of energy conservation in underwater acoustic sensor networks for long‐term marine monitoring applications. We propose an asynchronous wake‐up scheme based on combinatorial designs to minimize the working duty cycle of sensor nodes. We prove that network connectivity can be properly maintained using such a design even with a reduced duty cycle. We study the utilization ratio of the sink node and the scalability of the network using multiple sink nodes. Simulation results show that the proposed asynchronous wake‐up scheme can effectively reduce the energy consumption for idle listening and can outperform other cyclic difference set‐based wake‐up schemes. More significantly, high performance is achieved without sacrificing network connectivity. Copyright © 2015 John Wiley & Sons, Ltd.

Ballooning: An Agent-Based Search Strategy in Wireless Sensor and Actor Networks

Due to the actor mobility and duty cycle of sensor nodes, the data forwarding from sensor nodes to mobile actors is a challenging issue. Motivated by the research results in multi-agent systems, we consider the search packet as an agent moving in the network to search mobile actors. Then a strategy called ballooning is proposed to control the search process. The theoretical and numerical results show that the ballooning strategy can forward the search packet to mobile actors with bounded delay and efficient energy consumption.