EAGER: Fundamentals of Wireless Networks using Metamaterial-enhanced Magnetic Induction

现有的无线网络不能在许多恶劣和复杂的环境中运行，包括地下、水下、油藏、地下水含水层、核电站、管道、隧道和混凝土建筑物。这种环境中的无线网络能力可以实现环境、工业、国土安全、执法和军事领域的重要应用，例如使用无线传感器网络监测和维护地下水和/或油藏，使用机器人群对核电站进行损害评估和减轻，或在未知隧道和掩体中向军事小队实时投射信息，等等。然而，恶劣的无线信道阻碍了电磁（EM）波技术的直接使用，因为穿透损耗介质时材料的高吸收率。此外，由于实际环境可能是空气、水、土壤、混凝土和金属的复杂组合，因此仅适用于单一介质的解决方案（例如水下介质的声波网络）是行不通的。为此，本项目研究了基于一种新的通信机制的无线网络，即超材料增强磁感应（M2I），它可以在上述恶劣和复杂的环境中建立可靠的无线连接。该项目可以消除现有无线应用的环境障碍，并从根本上改变当前的通信和传感系统。该项目将通过数学建模、仿真和实验评估的闭环组合，探索基于m2i的无线网络的基础。M2I使用磁感应（MI）作为物理信号载体，以达到最佳穿透效果。与大多数MI技术中非常有限的范围不同，M2I利用每个天线外面的超材料层来实现实际应用中合理的通信范围（口袋大小的设备可以达到数十米）。此外，无线网络中的所有节点以及环境中的导电对象都是强耦合在一起的（由于M2I），形成了一个元环境，它实现了独特的网络功能，例如无源中继和环境感知定位。核心贡献主要集中在四个方面：(i) M2I天线建模和设计；（ii）新网络模式下的信道、干扰和容量分析；（iii）基于m2i认知能力的环境感知定位算法；（iv）通过基于Comsol Multiphysics和NS-3的跨层模拟器以及基于软件定义无线电和实验室制造超材料的试验台进行性能评估和原型设计。

Existing wireless networks do not perform in many hostile and complex environments, including the underground, underwater, oil reservoirs, groundwater aquifers, nuclear plants, pipelines, tunnels, and the concrete buildings. The wireless networking capability in such environments can enable important applications in the environmental, industrial, homeland security, law enforcement, and military fields, such as monitoring and maintenance of groundwater and/or oil reservoirs using wireless sensor networks, damage assessment and mitigation in nuclear plants using robot swarms, or real-time projection of information to and from military squads in unknown tunnels and bunkers, among others. However, the harsh wireless channels prevent the direct usage of the electromagnetic (EM) wave-based techniques due to the high material absorption when penetrating the lossy medium. Moreover, since practical environments can be complex combinations of air, water, soil, concrete, and metal, solutions only applicable for one single medium, e.g., acoustic wave based networking for underwater medium, do not work. To this end, this project investigates the wireless networks based on a new communication mechanism, i.e., metamaterial-enhanced magnetic induction (M2I), which can establish reliable wireless connections in the aforementioned hostile and complex environments. The project can eliminate the environmental barriers to existing wireless applications and radically change current communication and sensing systems.The project will explore the fundamentals of M2I-based wireless networks through a closed-loop combination of mathematical modeling, simulations, and experimental evaluation. M2I uses magnetic induction (MI) as the physical signal carrier for best penetration. Different from the very limited range in most MI techniques, M2I takes advantage of a metamaterial layer outside each antenna to achieve reasonable communication range for practical applications (tens of meters with pocket-sized devices). Moreover, all the nodes in the wireless network as well as the conductive objects in the environments are strongly coupled together (due to M2I), forming a Meta-environment, which enables unique networking functionalities, such as the passive relaying and environment-aware localization. The core contributions are in four main thrusts: (i) M2I antenna modeling and design; (ii) channel, interference, and capacity analysis under the new networking paradigm; (iii) environment-aware localization algorithms based on the M2I-enabled cognition capability; (iv) performance evaluation and prototyping through a cross layer simulator based on Comsol Multiphysics and NS-3, and a testbed based on software-defined radios and lab-fabricated metamaterials.