NeTS: Medium: Collaborative: Reliable Underwater Acoustic Video Transmission Towards Human-Robot Dynamic Interaction

在过去的十年中，水下通信已经实现了广泛的应用；然而，有一些新的水下监控应用和基于人-机器人动态交互的系统需要实时的多媒体采集和分类。遥控潜水器(ROV)是支持交互式应用的关键设备，因为它们可以从人类不容易/安全到达的地方捕获多媒体数据；然而，水下潜水器经常被光缆拴在支持船上，或者不得不周期性地浮出水面通过射频(RF)波与远程站通信，这限制了任务的执行。无线水声通信是典型的水声物理层通信技术，但由于声波具有衰减、带宽有限、多普勒扩展、高传播时延、高误码率和时变信道等特点，使得利用声波进行视频传输具有一定的难度。由于这些原因，最先进的声学通信解决方案仍然主要集中于实现延迟容忍、低带宽/低数据速率的标量数据传输，或者最好地实现数十Kbps量级的低质量/低分辨率多媒体流。因此，本研究计划的目标是：(1)设计新颖的通信解决方案，用于健壮、可靠和高数据率的数百千比特/秒(Kbps)的水下多媒体流；(2)研究基于软件定义的基于微电子机械(MEMS)的声学矢量传感器(AVSS)集成多种环境下的通信方法的问题，该结构将支持处理密集型物理层功能，如软件定义的，但在硬件中执行，可由用户根据体验质量(QOE)实时重新配置。在任务1中，将提出一种新的物理层解决方案，通过利用多天线阵列和AVS来提高水声传输的数据速率，从而在水下传输高分辨率视频。根据一种新的概率方法，设计了一种有效的媒体访问控制(MAC)层解决方案，通过使用AVSS来可靠地共享转向车辆之间的空间，从而减少声学干扰。通过应用基于利用AVSS估计的到达角度的稳健的闭环混合自动重传请求(ARQ)编码技术，将改善多媒体传输的质量。在任务2中，将对SEANet G2声学网络平台进行改进，以研究基于氮化铝(AlN)压电MEMS技术的新型小型化和集成化AVS阵列的设计和制造。最后，在任务3中，将定义使用Naviator、AVSS和SEANet试验床验证任务1中提出的想法的场景；任务2将通过将SEANet集成到浮标和导航器以及AVSS来构建用于进行视频传输实验的试验床来进行评估。任务1和任务2也将通过比较MEMS AVS和商用现成(COTS)AVS的优缺点，并通过评估半自主的人在环功能以提高用户质量来整合。该奖项反映了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 the past decade underwater communications have enabled a wide range of applications; there are, however, novel underwater monitoring applications and systems based on human-robot dynamic interaction that require real-time multimedia acquisition and classification. Remotely Operated Vehicles (ROVs) are key instruments to support such interactive applications as they can capture multimedia data from places where humans cannot easily/safely go; however, underwater vehicles are often tethered to the supporting ship by a fiber cable or have to rise periodically to the surface to communicate with a remote station via Radio Frequency (RF) waves, which constrains the mission. Wireless acoustic communication is the typical physical-layer technology for underwater communication; however, video transmissions via acoustic waves are hard to accomplish as the acoustic waves suffer from attenuation, limited bandwidth, Doppler spreading, high propagation delay, high bit error rate, and time-varying channel. For these reasons, state-of-the-art acoustic communication solutions are still mostly focusing on enabling delay-tolerant, low-bandwidth/low-data-rate scalar data transmission or at best low-quality/low-resolution multimedia streaming in the order of few tens of Kbps. Hence, the objectives of this research program are: (1) To design novel communication solutions for robust, reliable, and high-data rate underwater multimedia streaming on the order of hundreds of Kilobits per second (Kbps); (2) To investigate the problem of integrating communication methods available in multiple environments on an innovative software-defined testbed architecture integrating Microelectromechanical (MEMS)-based Acoustic Vector Sensors (AVSs) that will enable processing-intensive physical-layer functionalities as software-defined, but executed in hardware that can be reconfigured in real time by the user based on the Quality of Experience (QoE).By exploiting multiple-antenna arrays and AVSs, in Task 1 a novel physical-layer solution will be proposed to boost the data rate for underwater acoustic transmission so as to transfer high-resolution video underwater. By following a novel probabilistic approach, an efficient Medium Access Control (MAC) layer solution will be designed to share reliably the space among the steered vehicles by using AVSs so as to reduce the acoustic interference. The quality of multimedia delivery will be improved by applying a robust closed-loop hybrid Automatic Repeat Request (ARQ) coding technique based on the estimated angles of arrivals using AVSs. In Task 2, the SEANet G2 acoustic networking platform will be modified to investigate the design and fabrication of a new class of miniaturized and integrated AVS arrays based on the Aluminum Nitride (AlN) piezoelectric MEMS technology. Finally, in Task 3, scenarios will be defined to validate the ideas proposed in Task 1 using the Naviator, AVSs, and SEANet testbed; Task 2 will be evaluated by integrating SEANet to a buoy and the Naviator along with AVSs to build a testbed for conducting video transmission experiments. Tasks 1 and 2 will be also integrated by comparing the pros and cons of MEMs AVSs with Commercial Off-The-Shelf (COTS) AVSs and by evaluating the semi-autonomous human-in-the-loop features to enhance user QoE.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.