New Horizons in Optical Networking with Elastic Spectrum Allocation and Parallel Transmission

光纤容量限制的迫近推动了光并行化的需求，即通过空间分路复用（SDM）方式并行使用多个光通道。这一点最近引起了人们的极大关注，因为研究表明，如果没有并行化，未来对约20b/s/Hz频谱效率的要求将超出香农极限，因此用目前的技术无法实现。因此，高速以太网系统已经在40/100~千兆以太网（40/100GE）标准中采用并行化。其中，最近提出的基于弹性频谱分配和正交频分复用（OFDM）技术的弹性光网络已经成为一种潜在的变革性解决方案。这是由于它的基本能力，实际切片或并行的光谱成频率槽序列和调制信号在频率槽的子载波的形式，可以匹配并行端系统流。为了实现这一快速趋势的真正潜力，提出了一项为期三年的研究计划，其中包括三个主要研究重点，即(i)架构设计——专注于解决部署并行传输网络中的架构挑战，以及网络从固定频谱分配向灵活频谱分配的迁移，以实现超过100~Gb/s串行传输速率的可扩展容量增长；（ii）建模与算法设计——重点研究光并行传输的建模，包括并行路由、高级调制格式的灵活分配，以及利用灵活的光谱分配。（iii）网络编码并行传输——将网络编码应用于并行传输。以可扩展的系统设计为目标，研究网络编码是否有助于容错和可靠的高速光系统传输。为了测试提出的概念的有效性和可用性，我们计划使用分析，模拟和仿真。总的来说，拟议的研究计划为各种形式科学（例如，信息论，光纤传输，网络建模和算法）以及计算机工程（例如，网络和协议体系结构，并行计算）的基础研究提供了一个独特的平台。

The need for optical parallelization, where multiple optical channels are used in parallel by means of Spatial Division Multiplexing (SDM), is driven by the imminent capacity limit of optical fibers. This has gainedsignificant attention recently as it has been shown that without parallelization,the future requirement of about 20b/s/Hz spectral efficiency will bebeyond the Shannon limit, and thus unachievable with the current technologies.Consequently, the high-speed Ethernet systems have already resorted to parallelization in 40/100~Gigabit Ethernet (40/100GE) standards. Therein, the recently proposed elastic opticalnetworks based on elastic spectrum allocation and Orthogonal Frequency Division Multiplexing (OFDM) technologyhave emerged as a potentially transformative solution. This is due to its fundamentalcapability to actually slice or parallelize the optical spectrum into asequence of frequency slots and modulate signals on frequency slots in formof sub-carriers that can match parallel end-system streams.To deliver on the true potential of this rapid trend, a three-year researchprogram is proposed including three main research thrusts, namely, (i)Architectural Design - focusing on addressing architectural challenges in networks deploying parallel transmissionalong with the network migration from fixed to flexible spectrum allocation, towards ascalable capacity increase beyond the 100~Gb/s serial transmission rates, (ii) Modeling and Algorithmic Design - focusing on modeling of optical parallel transmission, including parallel routing, flexible assignment of advanced modulation formats, aswell as taking advantage of flexible optical spectrum allocation, and,(iii) Network Coded Parallel Transmission - applying network coding to paralleltransmission, with the goal of scalable system design as well as to investigate whether network coding can contribute to fault-tolerant and reliable high-speed optical system transmission.To test the proposed concept on its validity and usability, we plan to useanalysis, simulations, as well as emulations. In its entirety, the proposed research program provides a unique platform forfundamental research across a diverse spectrum of formal sciences (e.g.,information theory, fiber transmission, network modeling, and algorithms), aswell as computer engineering (e.g., network and protocol architecture, parallel computing).