EAGER: Terabit DSL

EAGER：太比特 DSL

• 批准号: 1842023
• 负责人: Daniel Mittleman
• 金额: $ 20万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-10-01 至 2020-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1842023&HistoricalAwards=false
• 关键词: EAGER; Terabit; DSL

EAGER: Transmitting data at a terabit per second on twisted copper wiresThe transmission of data using twisted copper-wire pairs was pioneered by Alexander Graham Bell in 1881. Today, there are well over a billion such twisted pairs installed globally, an infrastructure which has been the basis for nearly all telephone connections for over 100 years. In the late 1980s Digital Subscriber Line (DSL) services were developed, in which an RF signal carrying digital data was essentially piggy-backed on top of the same copper wires used for analog voice signals. Through advances in data encoding and frequency multiplexing, these systems can now typically deliver data at gigabit per second rates. The astounding (and ongoing) commercial success of DSL arises largely from the fact that these services do not require new wire or fiber connections (which cost thousands of dollars per customer to install), but instead can deliver high bit rates to customers using the existing infrastructure. However, advances in encoding and multiplexing have nearly reached their limit, so the only way to further increase the data rate is to increase the frequency of the RF carrier wave, since there is more bandwidth available at higher frequencies. The proposed research will explore the use of these existing copper twisted-cables for transmission of signals at much higher frequencies than those that have previously been employed in DSL systems. Similar multiplexing and encoding schemes will be necessary, due to the unavoidable mixing of these high-frequency signals as they propagate along these non-uniform cables. If these signal processing approaches are still useful at high frequencies, and if the overall signal loss is not too high, then this initial demonstration will validate the feasibility of operating a DSL-like system with a data rate of a terabit per second, vastly higher than anything that has been envisioned previously. This would open up an entirely new realm for fixed (not wireless) data services.This EAGER proposal suggests a radically new way to think about DSL transmission systems. In all discussions to date, the fundamental physics of the electromagnetic signal propagation is described using the language of transmission lines. Conventionally, a transmission line guides an electrical signal by propagation of a time-varying voltage between a pair of electrically isolated conductors. However, when the free-space wavelength of the guided wave approaches the relevant dimensions (e.g., the distance between the two conductors), it is more appropriate to describe this transmission process using the language of waveguides. Inspired by the fact that the typical free-space distance between wires in a twisted-wire pair can be on the order of a millimeter, this project seeks to study the use of millimeter waves or terahertz waves as the carriers for modulated digital data on twisted-pair cables, acting as waveguides. This proposal seeks to initiate a research collaboration between the PI at Brown University and engineers at ASSIA, Inc. This company specializes in the software and signal processing that enables efficient use of spectrum in DSL systems. Their expertise, in particular in the area of vectoring (conceptually equivalent to MIMO in wireless systems), combined with the PI's expertise in millimeter-wave and terahertz waveguides, represents a unique team which is ideally positioned to carry out the proposed exploratory research program. The approach involves the experimental characterization of the waveguide modes (all output modes for each possible input excitation) for a set of model cable systems, starting from a simple single-twisted-pair and working up to more complicated (and longer) waveguides. The effects of modal dispersion, dielectric loss, and bends will be studied, and the results will be used as inputs in channel models developed by ASSIA to predict the rate and range performance characteristics. This work represents the first realistic exploration of the idea of using millimeter waves for long-distance guided-wave data transmission.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.

急切：1881年，亚历山大·格雷厄姆·贝尔（Alexander Graham Bell）在使用扭曲的铜线传输数据传输数据时以每秒的速度传输数据。如今，在全球安装了超过数十亿个这样的扭曲对，这是一个超过100年来连接的基础设施，这是一种基础结构。在1980年代后期，开发了数字用户线（DSL）服务，其中携带数字数据的RF信号基本上是在用于模拟语音信号的相同铜线之上贴上的。通过数据编码和频率多路复用的进步，这些系统现在通常可以以千兆位每秒的价格传递数据。 DSL的惊人（和持续）商业成功很大程度上是由于这些服务不需要新的电线或光纤连接（每个客户要安装数千美元），而是可以使用现有基础架构向客户提供高比特费率。但是，编码和多路复用的进步几乎已经达到了极限，因此进一步提高数据速率的唯一方法是增加RF载波波的频率，因为在较高频率下可用的带宽更多。拟议的研究将探索这些现有的铜扭曲缆车的使用，以比以前在DSL系统中使用的频率要高得多的信号传输。由于这些高频信号不可避免地混合在这些不均匀的电缆时，因此需要类似的多路复用和编码方案。如果这些信号处理方法仍在高频下仍然有用，并且如果总体信号损失不太高，则该初始演示将验证操作类似DSL的系统的可行性，其数据速率每秒的数据速率为每秒的数据速率，大大高于以前所设想的任何事物。这将为固定（非无线）数据服务打开一个全新的领域。此急切的建议提出了一种思考DSL传输系统的新方法。在迄今为止的所有讨论中，使用传输线的语言描述了电磁信号传播的基本物理。通常，传输线通过在一对电离导体之间传播时变电压来引导电信号。但是，当引导波的自由空间波长接近相关维度（例如，两个导体之间的距离）时，使用波导语言来描述这种传输过程更为合适。受扭曲对中电线之间的典型自由空间距离的启发，该项目旨在研究使用毫米毫米波或Terahertz Waves的使用，作为在扭曲对准电缆上调制数字数据的载体，用作波导。该建议旨在启动Brown University PI与Assia Inc.工程师之间的研究合作。该公司专门从事软件和信号处理，该软件和信号处理能够有效利用DSL系统中的频谱。它们的专业知识，尤其是在矢量方面（概念上等同于无线系统中的MIMO），并结合了PI在毫米波和Terahertz WaveGuides方面的专业知识，代表了一个独特的团队，它是一支理想地实现的，可以实现拟议的探索性研究计划。该方法涉及一组模型电缆系统的波导模式（每种可能输入激发的所有输出模式）的实验表征，从简单的单twist型对开始，并起到更为复杂（且更长的）波导。将研究模态分散，介电损失和弯曲的影响，结果将用作Assia开发的通道模型中的输入，以预测速率和范围性能特征。这项工作代表了对使用毫米波进行长距离指导波数据传输的想法的第一个现实探索。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来支持。

项目成果

A metal wire waveguide for terabit DSL

用于太比特 DSL 的金属线波导

• DOI: 10.1109/irmmw-thz.2019.8873828
• 发表时间: 2019
• 期刊: and Terahertz Waves (IRMMW-THz
• 作者: Shrestha, Rabi;Kerpez, Kenneth;Hwang, Chan Soo;Mohseni, Mehdi;Cioffi, John;Mittleman, Daniel M.
• 通讯作者: Mittleman, Daniel M.

A wire waveguide channel for terabit-per-second links

• DOI: 10.1063/1.5143699
• 发表时间: 2020-03-30
• 期刊: APPLIED PHYSICS LETTERS
• 影响因子: 4
• 作者: Shrestha, Rabi;Kerpez, Kenneth;Mittleman, Daniel M.
• 通讯作者: Mittleman, Daniel M.