Jin Zhigang, Wang Ning, Su Yishan, Yang Qiuling
School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.
College of Information Science and Technology, Hainan University, Haikou 570228, China.
Sensors (Basel). 2018 Feb 7;18(2):501. doi: 10.3390/s18020501.
Underwater acoustic sensor networks (UASNs) have become a hot research topic. In UASNs, nodes can be affected by ocean currents and external forces, which could result in sudden link disruption. Therefore, designing a flexible and efficient link disruption restoration mechanism to ensure the network connectivity is a challenge. In the paper, we propose a glider-assisted restoration mechanism which includes link disruption recognition and related link restoring mechanism. In the link disruption recognition mechanism, the cluster heads collect the link disruption information and then schedule gliders acting as relay nodes to restore the disrupted link. Considering the glider's sawtooth motion, we design a relay location optimization algorithm with a consideration of both the glider's trajectory and acoustic channel attenuation model. The utility function is established by minimizing the channel attenuation and the optimal location of glider is solved by a multiplier method. The glider-assisted restoration mechanism can greatly improve the packet delivery rate and reduce the communication energy consumption and it is more general for the restoration of different link disruption scenarios. The simulation results show that glider-assisted restoration mechanism can improve the delivery rate of data packets by 15-33% compared with cooperative opportunistic routing (OVAR), the hop-by-hop vector-based forwarding (HH-VBF) and the vector based forward (VBF) methods, and reduce communication energy consumption by 20-58% for a typical network's setting.
水下声学传感器网络（UASNs）已成为一个热门的研究课题。在水下声学传感器网络中，节点会受到洋流和外力的影响，这可能导致链路突然中断。因此，设计一种灵活高效的链路中断恢复机制以确保网络连通性是一项挑战。在本文中，我们提出了一种滑翔器辅助恢复机制，该机制包括链路中断识别和相关的链路恢复机制。在链路中断识别机制中，簇头收集链路中断信息，然后调度滑翔器作为中继节点来恢复中断的链路。考虑到滑翔器的锯齿形运动，我们设计了一种中继位置优化算法，该算法同时考虑了滑翔器的轨迹和声信道衰减模型。通过最小化信道衰减来建立效用函数，并使用乘子法求解滑翔器的最优位置。滑翔器辅助恢复机制可以大大提高数据包传输率，降低通信能耗，并且对于不同链路中断场景的恢复更具通用性。仿真结果表明，与协作机会路由（OVAR）、逐跳向量转发（HH-VBF）和基于向量的转发（VBF）方法相比，滑翔器辅助恢复机制可以将数据包的传输率提高15% - 33%，在典型网络设置下，通信能耗降低20% - 58%。
