SpecEES: Collaborative Research: Efficient and Secure Access to Spectrum up to THz

自马可尼时代以来，批评者就抱怨无线传输缺乏安全性，而且速度太慢，以至于一个骑着小马的男孩可能是更快的传输信息的方式，正如拜伦勋爵在1898年的一句著名俏皮话。一个多世纪后，太赫兹（THz）尺度频谱的每秒太比特链路即将出现，高度定向的波束已被设计为安全的。然而，即使是太赫兹链路也会变得“太慢”，如果它们在为移动客户端反复重新对准波束时遭受中断。同样，虽然60千兆赫（GHz）频段因其提高的安全性而受到称赞，但不幸的是，即使是铅笔波束的太赫兹频段也容易受到敏捷的窃听者的攻击。因此，该项目的目标是设计、实施和实验探索概念验证系统，以实现无线局域网（WLAN）架构，该架构具有从100 GHz到1 THz的高效和安全的频谱访问，WLAN规模范围可达120米。该项目将建立在太赫兹级设备和频谱支持的基本新传输能力的基础上。第一个项目将实现Leaky X-Agon，这是一种首创的多面漏波导WLAN架构。这种结构将频率和转向角结合起来，提供频率选择的自适应波束转向，从而实现前所未有的链路空间密度。此外，通过在每个面上传输宽带“太赫兹彩虹”，实现了波束转向和频率选择的新基础：通过以不同角度发射不同频率，接收器可以同时识别所有传播路径及其转向角度，而不是耗时且低效的试错测试。第二个项目的重点是解决安全性问题，并提供实验分析和应对措施，以确保从100 GHz到1太赫兹的频谱接入。在强大的对手威胁模型下，该项目将开发使用太赫兹反向散射和太赫兹彩虹失真来检测和避开窃听者可能用来帮助拦截传输的物体的方法。此外，提出了一种新的吸收调谐方法来调谐传输范围，使超出预期接收器位置的拦截不可行。使用精确的经验模型，该方法将载波频率调谐到接近水蒸气吸收共振的频率，从而对大气传播损耗进行精确控制，从而对传输范围进行精确控制。所有项目组件都具有广泛的实施和实验计划，用于空中实验和验证。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Since the days of Marconi, critics complained that wireless transmission lacked security and was so slow that a boy on a pony would be a faster way to transmit a message, as Lord Byron famously quipped in 1898. Over a century later, terabit-per-second links in terahertz (THz) scale spectrum are around the corner and highly directional beams have been decreed secure by design. However, even THz links can become "too slow" if they suffer from outages while repeatedly re-aligning beams for mobile clients. Likewise, while 60 gigahertz (GHz) bands have been lauded for their improved security, unfortunately, even pencil-beam THz-scale links can be vulnerable to agile eavesdroppers. Consequently, this project targets to design, implement, and experimentally explore proof-of-concept systems to realize a Wireless Local Area Network (WLAN) architecture with efficient and secure access to spectrum from 100 GHz up to 1 THz and WLAN-scale range up to 120 meters. This project will build on fundamental new transmission capabilities enabled by THz-scale devices and spectrum. The first project thrust will realize Leaky X-Agon, a first-of-its-kind multi-face leaky waveguide WLAN architecture. This architecture couples frequency and steering angle to provide frequency-selective adaptive beam steering enabling unprecedented spatial density of links. Moreover, a new foundation for beam steering and frequency selection is realized via transmission of a wideband "THz rainbow" on each face: by emitting different frequencies at different angles, the receiver can identify all propagation paths and their steering angles simultaneously, as opposed to time-consuming and inefficient trial-and-error testing that is commonly employed today. The second project thrust addresses security and provides experimental analysis and counter-measures for securing spectrum access from 100 GHz to 1 THz. Under a strong adversary threat model, this project thrust will develop methods using THz backscatter and THz rainbow distortion to detect and avoid objects that an eavesdropper may be using to aid interception of a transmission. Moreover, a novel absorption tuning method is proposed to tune the transmission range so that interception beyond the location of the intended receiver is not viable. Using accurate empirical models, the method will tune the carrier frequency to be close to that of a water vapor absorption resonance, yielding exquisite control of the atmospheric propagation loss, and therefore of the transmission range. All project components feature an extensive implementation and experimental plan for over-the-air experiments and validation.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.