School of Information Science and Engineering, Central South University, Changsha 410083, China.
School of Informatics, Hunan University of Chinese Medicine, Changsha 410208, China.
Sensors (Basel). 2018 Aug 31;18(9):2885. doi: 10.3390/s18092885.
In energy harvesting wireless sensor networks (EHWSNs), the energy tension of the network can be relieved by obtaining the energy from the surrounding environment, but the cost on hardware cannot be ignored. Therefore, how to minimize the cost of energy harvesting hardware to reduce the network deployment cost, and further optimize the network performance, is still a challenging issue in EHWSNs. In this paper, an energy conserving and transmission radius adaptive (ECTRA) scheme is proposed to reduce the cost and optimize the performance of solar-based EHWSNs. There are two main innovations of the ECTRA scheme. Firstly, an energy conserving approach is proposed to conserve energy and avoid outage for the nodes in hotspots, which are the bottleneck of the whole network. The novelty of this scheme is adaptively rotating the transmission radius. In this way, the nodes with maximum energy consumption are rotated, balancing energy consumption between nodes and reducing the maximum energy consumption in the network. Therefore, the battery storage capacity of nodes and the cost on hardware. Secondly, the ECTRA scheme selects a larger transmission radius for rotation when the node can absorb enough energy from the surroundings. The advantages of using this method are: (a) reducing the energy consumption of nodes in near-sink areas, thereby reducing the maximum energy consumption and allowing the node of the hotspot area to conserve energy, in order to prevent the node from outage. Hence, the network deployment costs can be further reduced; (b) reducing the network delay. When a larger transmission radius is used to transmit data in the network, fewer hops are needed by data packet to the sink. After the theoretical analyses, the results show the following advantages compared with traditional method. Firstly, the ECTRA scheme can effectively reduce deployment costs by 29.58% without effecting the network performance as shown in experiment analysis; Secondly, the ECTRA scheme can effectively reduce network data transmission delay by 44⁻71%; Thirdly, the ECTRA scheme shows a better balance in energy consumption and the maximum energy consumption is reduced by 27.89%; And lastly, the energy utilization rate is effectively improved by 30.09⁻55.48%.
在能量收集无线传感器网络（EHWSNs）中，可以通过从周围环境中获取能量来缓解网络的能量紧张问题，但硬件成本也不容忽视。因此，如何最小化能量收集硬件成本以降低网络部署成本，并进一步优化网络性能，仍然是 EHWSNs 中的一个具有挑战性的问题。在本文中，提出了一种节能和传输半径自适应（ECTRA）方案，以降低成本并优化基于太阳能的 EHWSNs 的性能。ECTRA 方案有两个主要创新点。首先，提出了一种节能方法，以避免热点中的节点（整个网络的瓶颈）出现能量耗尽和停机的情况。该方案的新颖之处在于自适应地旋转传输半径。通过这种方式，旋转具有最大能耗的节点，从而平衡节点之间的能量消耗，并降低网络中的最大能耗。因此，可以减少节点的电池存储容量和硬件成本。其次，当节点可以从周围环境中吸收足够的能量时，ECTRA 方案会为旋转选择更大的传输半径。使用这种方法的优点是：(a) 减少近汇节点的能量消耗，从而降低最大能耗，使热点区域的节点能够节能，以防止节点停机。因此，可以进一步降低网络部署成本；(b) 减少网络延迟。当网络中使用更大的传输半径来传输数据时，数据分组到达汇点所需的跳数更少。在理论分析之后，结果表明与传统方法相比，该方案具有以下优势。首先，ECTRA 方案在不影响网络性能的情况下，可以有效地将部署成本降低 29.58%；其次，ECTRA 方案可以有效地将网络数据传输延迟降低 44-71%；第三，ECTRA 方案在能量消耗方面表现出更好的平衡，最大能耗降低了 27.89%；最后，能量利用率提高了 30.09-55.48%。
