NeTS: Medium: Networking Out of Thin Air

该项目建议为环境后向散射奠定算法基础，这是一种新型的通信机制，它将现有的无线信号(例如，电视、蜂窝和Wi-Fi传输)转换为电源和通信介质：因此，无需额外的带宽和/或功率即可实现通信。环境后向散射网络有可能引入一种新的实用通信模式；减少全球范围内的电池使用量和小型计算设备的能源消耗；并减少维持电力的人力和经济成本。这项拟议的研究如果成功，可以打开包括物联网、可穿戴设备和移动设备在内的多个领域的无处不在的通信应用，以及免基础设施的本地化。随着小型物联网设备越来越多地嵌入对象和环境中，如恒温器、书籍、家具，甚至植入式医疗设备；像环境后向散射这样的新颖原语将使无处不在的通信能够以前所未有的规模(没有电池或电线)以及在以前无法实现的地点和时间(白天和夜晚，室内和室外)实现。此外，由于环境后向散射比传统无线电通信消耗的功率低几个数量级，因此它可以为智能手机和平板电脑等电池供电的移动设备以及头戴式显示器和智能手表等可穿戴设备实现始终在线通信。最后，由于有了环境后向散射，无电池设备可以相互通信，它们知道自己的环境和周围的设备；这使得在仓库和医疗设施中定位遗失物品是不可能的，而不需要广泛部署电力基础设施。拟议的研究将产生算法、设计、电路和系统实现，使通信和联网能够凭空实现。实现这一目标的关键挑战是，电视、蜂窝和Wi-Fi传输等现有信号已经承载了数据，并且是快速变化的信号；在这些信号之上传输额外的信息可能是具有挑战性的。此外，由于所提出的设备是使用这些环境信号来供电的，因此需要能够有效地从其中获取能量的电路设计。这项研究将设计在不需要额外带宽和/或功率的情况下实现通信的算法。该项目还将为这一新的通信原语设计一个完整的网络堆栈，使多个此类设备能够彼此共存以及与传统接收器共存，并利用算法和技术来实现无电池本地化等新功能，并展示它们在包括库存和医疗保健在内的多个领域的应用。

This project proposes to lay the algorithmic foundations for ambient backscatter, a novel communication mechanism that transforms existing wireless signals (e.g., TV, cellular, and Wi-Fi transmissions) into both a source of power as well as a communication medium: thus, enabling communication without requiring additional bandwidth and/or power. Ambient backscatter networks have the potential to introduce a new practical model of communication; reduce world-wide battery usage and energy consumption of small computing devices; and reduce the human and economic costs of maintaining power. The proposed research, if successful, can open up ubiquitous communication applications in multiple domains including Internet-of-Things, wearable and mobile devices, as well as infrastructure-free localization. As small Internet-of-Things devices are increasingly embedded in objects and environments such as thermostats, books, furniture, and even implantable medical devices; a novel primitive like ambient backscatter would enable ubiquitous communication at unprecedented scales (without batteries or wires) and in location and times that were previously infeasible (day and night, indoors and outdoors). Further, since ambient backscatter consumes orders of magnitude lower power than traditional radio communication, it can enable always-on communication for battery-operated mobile devices such as smart phones and tablets as well as wearable devices such as head-on displays and smart watches. Finally, since with ambient backscatter, battery-free devices can communicate with each other, they are aware of their context and the devices around them; this enables missing-item localization in warehouses and medical facilities that are infeasible with existing RFID technologies, without an extensive deployment of power infrastructure.The proposed research will produce algorithms, designs, circuits, and system implementations that will enable communication and networking out of thin air. The key challenge in achieving this is that existing signals such as TV, cellular, and Wi-Fi transmissions already carry data and are fast-changing signals; transmitting additional information on top of these signals can be challenging. Further, since the proposed devices are powered using these ambient signals, circuit designs that can harvest energy from them efficiently are needed. This research will design algorithms for enabling communication without requiring additional bandwidth and/or power. This project will also design a complete network stack for this new communication primitive that will enable multiple such devices to co-exist with each other as well as with legacy receivers and leverage algorithms and techniques to enable new functionalities such as battery-free localization and demonstrate their applications in a number of domains including inventory, and healthcare.