CCSS: Medium: Enabling Access and Topology Optimization of Underwater Networks through an Aerial Units Vehicle

近年来，人们对水声网络的应用越来越感兴趣。目前，浮动节点用于通过无线电链路将UAN连接到非海基单元，并将水下节点的位置与全球坐标系相关联。然而，这种方法对于延长任务可能不切实际，对于快速反应情况无效，并且/或者对于秘密行动是不可取的。此外，由于节点漂移和水下环境的时变特性，对缓解UAN连接频繁中断的关注很少。为了解决这些问题，本研究项目促进了创新通信机制的发展，使UAN直接连接到空中移动单元(AMU)，而不需要浮动节点。这一成果可以提高许多涉及国家和国际利益的民用和科学应用的有效性。这些应用的例子包括搜救、海岸巡逻、海洋数据收集、环境监测、辅助导航和安全监视。此外，该项目将丰富计算机网络、无线通信、传感器网络、激光以及嵌入式和分布式系统方面的本科生和研究生课程。计划与当地社区大学和高中进行接触，以宣传水下研究并招收学生参加STEM教育。密歇根大学迈耶霍夫奖学金和CWIT(妇女与信息中心)。技术。)该计划将积极招收女性和少数民族学生。该项目选择开发一套协议，使UAN和AMU之间能够直接双向通信。然后利用这些协议来扩展水下环境中的全球坐标系，以帮助定位和拓扑管理。具体的技术贡献是：(1)为UAN和AMU之间的可靠双向通信开发协议。光声效应将被用来创建下行链路，通过将机载激光光束引导到水面来产生编码的水声信号。另一方面，上行链路是通过激光多普勒测振仪建立的，该测振仪将检测从水下节点到水面的入射声学传输引起的撞击和突出；(2)设计编码和调制方案，以适应通过空气-水界面的传输。将研究水下覆盖范围、有效信道容量、误码率等方面的基本限制；(3)开发利用与AMU通信的网络发现和定位协议，以建立水下全球坐标系。这是通过利用飞行器进行编码的光声传输以在水面上生成链接到陆地全球坐标系(例如GPS)的参考点来实现的；(4)开发拓扑管理协议，其利用AMU来减轻节点漂移并重新建立与节点或孤立节点块的断开的声学链路。验证计划通过试验台和现场实验进行。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In recent years, there is an increased interest in the applications of underwater acoustic networks (UANs). Currently, floating nodes are used to interface the UAN through radio links to non-sea-based units and to correlate the position of underwater nodes to a global coordinate system. However, such an approach could be impractical for extended missions, ineffective for rapid response scenarios, and/or undesirable for covert operations. Moreover, little attention has been paid to mitigating frequent breaks in UAN connectivity due to node drifts and time varying property of the underwater environment. To address these issues, this research project promotes the development of innovative communication mechanisms for interfacing UANs directly to an aerial mobile unit (AMU) without the need of floating nodes. The outcome can boost the effectiveness of many civil and scientific applications of a national and international interest. Examples of these applications include search-and-rescue, coastal patrol, oceanographic data collection, environmental monitoring, assisted navigation, and security surveillance. Furthermore, the project will enrich the undergraduate and graduate curricula in computer networks, wireless communication, sensor networks, lasers, and embedded and distributed systems. Outreach to local community colleges and high schools is planned in order to publicize underwater researches and recruit students to STEM education. UMBC's the Meyerhoff Scholarship, and CWIT (Center for Women & Info. Tech.) programs will be exploited to actively recruit female and minority students.The project opts to develop a suite of protocols enabling direct two-way communication between UANs and AMUs. These protocols are then leveraged to extend the global coordinate system in the underwater environment to aid in localization and topology management. The specific technical contributions are: (1) Develop protocols for reliable bidirectional communication between the UAN and an AMU. The optoacoustic effect will be utilized to create a downlink where encoded underwater acoustic signals are generated by directing airborne laser beams to the water surface. The uplink, on the other hand, is established by means of a laser Doppler vibrometer that will detect impinging and protrusion caused by an incident acoustic transmission from an underwater node onto the water surface; (2) Devise encoding and modulation schemes to suit transmission across the air-water interface. Fundamental limitations in terms of underwater reach, effective channel capacity, bit error rate, etc., will be studied; (3) Develop a network discovery and localization protocol that leverages communication with the AMU to enable the establishment of underwater global coordinate system. This is accomplished by utilizing the aerial vehicle in making encoded optoacoustic transmissions to generate reference points on the water surface linked to a terrestrial global coordinate system, e.g. GPS; (4) Develop topology management protocols that utilizes the AMUs in mitigating node drifts and re-establishing broken acoustic links with a node or an isolated block of nodes. Validation is planned through test-beds and field experiments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.