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

自马可尼时代以来，批评家们就抱怨无线传输缺乏安全性，速度太慢，以至于一个骑着小马的男孩会更快地传递信息，正如拜伦勋爵在1898年的一句名言。 世纪后，太赫兹（THz）级频谱中的每秒太比特链路即将到来，并且高度定向的波束已被设计为安全的。 然而，如果THz链路在为移动的客户端重复重新对准波束时遭受中断，则即使THz链路也可能变得“太慢”。同样，虽然60千兆赫（GHz）频段因其改进的安全性而受到称赞，但不幸的是，即使是双波束太赫兹级链路也容易受到敏捷窃听者的攻击。 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，有效和安全地访问从100 GHz到1 THz的频谱，WLAN规模范围可达120米。该项目将建立在由太赫兹级设备和频谱实现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。该架构耦合频率和转向角以提供频率选择性自适应波束转向，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，而不是当今常用的耗时且低效的试错测试。 第二个项目重点是解决安全问题，并提供实验分析和应对措施，以确保从100 GHz到1 THz的频谱接入。在强大的对手威胁模型下，该项目将开发使用THz反向散射和THz彩虹失真的方法，以检测和避免窃听者可能用于帮助拦截传输的对象。 此外，提出了一种新的吸收调谐方法来调谐传输范围，使拦截超出预定接收器的位置是不可行的。使用精确的经验模型，该方法将调整载波频率接近水蒸气吸收共振的频率，从而精确控制大气传播损耗，从而控制传输范围。 该奖项反映了NSF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.