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.

EAGER：在双绞铜线上以每秒太比特的速度传输数据 使用双绞铜线传输数据是由 Alexander Graham Bell 于 1881 年首创。如今，全球安装了超过 10 亿对这样的双绞线，这一基础设施已得到广泛应用。 100 多年来几乎所有电话连接的基础。 20 世纪 80 年代末，数字用户线路 (DSL) 服务得到发展，其中承载数字数据的射频信号本质上是搭载在用于模拟语音信号的相同铜线上。通过数据编码和频率复用的进步，这些系统现在通常可以以每秒千兆位的速率传输数据。 DSL 令人震惊（且持续）的商业成功很大程度上源于这样一个事实：这些服务不需要新的有线或光纤连接（每个客户的安装成本数千美元），而是可以使用现有的网络向客户提供高比特率。基础设施。然而，编码和复用技术的进步已接近极限，因此进一步提高数据速率的唯一方法是提高射频载波的频率，因为更高的频率有更多的可用带宽。拟议的研究将探索如何使用这些现有的铜绞线以比以前在 DSL 系统中使用的频率高得多的频率传输信号。由于这些高频信号在沿着这些不均匀电缆传播时不可避免地会混合，因此需要类似的复用和编码方案。如果这些信号处理方法在高频下仍然有用，并且总体信号损失不是太高，那么这个初始演示将验证以每秒 1 太比特的数据速率运行类似 DSL 的系统的可行性比之前设想的任何事情都要多。这将为固定（非无线）数据服务开辟一个全新的领域。这个 EAGER 提案提出了一种思考 DSL 传输系统的全新方法。在迄今为止的所有讨论中，电磁信号传播的基本物理原理都是使用传输线的语言来描述的。传统上，传输线通过在一对电隔离导体之间传播时变电压来引导电信号。然而，当导波的自由空间波长接近相关尺寸（例如两个导体之间的距离）时，使用波导的语言来描述这种传输过程更为合适。受双绞线中导线之间的典型自由空间距离可以达到毫米量级这一事实的启发，该项目旨在研究使用毫米波或太赫兹波作为双绞线上调制数字数据的载体。 - 成对电缆，充当波导。该提案旨在启动布朗大学的 PI 与 ASSIA, Inc. 的工程师之间的研究合作。该公司专门从事软件和信号处理，可实现 DSL 系统中频谱的高效利用。他们的专业知识，特别是矢量领域的专业知识（概念上相当于无线系统中的 MIMO），与 PI 在毫米波和太赫兹波导方面的专业知识相结合，代表了一支独特的团队，非常适合开展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（每种可能输入激励的所有输出模式）的实验表征，从简单的单双绞线开始，一直到更复杂（和更长）的波导。我们将研究模式色散、介电损耗和弯曲的影响，并将结果用作 ASSIA 开发的通道模型的输入，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导波数据传输的想法的首次现实探索。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。

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: 2019-09
• 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

用于太比特每秒链路的有线波导通道

• DOI: 10.1063/1.5143699
• 发表时间: 2020-03
• 期刊: Applied physics letters
• 影响因子: 4
• 作者: Rabi Shrestha; Kenneth Kerpez
• 通讯作者: Kenneth Kerpez