Intrachannel nonlinearity is considered a major distortion in high-capacity transmission systems particular for the case without inline optical chromatic dispersion compensation. In this paper, low-complexity intrachannel nonlinear compensator operating at symbol rate proposed based on perturbation predistortion dual-polarization quadrature phase-shift keying (DP-QPSK) systems. Compared with widely studied backpropagation algorithm, algorithm achieves comparable performance significantly...

A wireless sensor network consists of hundreds or thousands small energy-limited sensors that are densely deployed in a large geographical region. It has been demonstrated Low-Energy Adaptive Clustering Hierarchy (LEACH) is an energy-efficient routing algorithm for Wireless Sensor Networks (WSN). In this paper, we present Time-based Cluster-Head Selection Algorithm LEACH. We call new protocol TB-LEACH. state the principle TB-LEACH and give main flowchart pseudo codes realizing provide...

One stage per span is commonly considered as the lower boundary for implementation complexity of nonlinear equalizer based on digital backpropagation. The proposed method overcomes this and improves efficiency by about four times.

In this paper, we present Alibaba’s practices and views on open disaggregated optical transport networks, with a focus metro data center interconnects (DCIs). We first discuss technology developments that have enabled followed by presentation of our network architecture for DCI networks. then describe an overall the application scenario technology. Details point-to-point need reconfigurable add–drop multiplexers (ROADMs) in networks are discussed. models equipment, including terminal...

A novel back-propagation algorithm is proposed based on perturbation analysis to compensate the intra-channel nonlinearity. It reduces 85% stages in an experiment of dual polarization QPSK transmission over 1500 km dispersion uncompensated link.

Conventional Gardner clock recovery method fails on Nyquist signal with sinc pulse shape. A novel algorithm is proposed and verified by experiment. It has lower timing jitter, its tolerance to various distortions investigated.

While there have been various studies towards Android apps and their development, is limited discussion of the broader class that fall in fake area. Fake development are distinct from official belong to mobile underground industry. Due lack knowledge industry, apps, ecosystem nature still remain mystery. To fill blank, we conduct first systematic comprehensive empirical study on a large-scale set apps. Over 150,000 samples related top 50 popular collected for extensive measurement. In this...

We propose a low complexity intra-channel nonlinearity pre-distortion method based on symbol rate operation. The is experimentally verified under 43Gb/s DP-QPSK coherent system, and the performance comparable with back-propagation method.

Accurate quality of transmission (QoT) estimations are essential enablers for future low-margin dynamic optical network operations. However, physical parameter measurement uncertainties and other intractable signal propagation effects degrade the accuracy QoT estimation, especially in live production networks. The recent trend disaggregation further exacerbates issue, a vendor-agnostic accurate estimator is much needed. In this paper, we study Gaussian-noise-model-based estimation...

The phase noise induced by the intra-channel nonlinearity with DP-16QAM is found to be higher than that DP-QPSK in 1600km transmission experiments. main reason identified as large IXPM 16QAM based on proposed nonlinear model.

Intrachannel nonlinearity is considered as a major distortion in high capacity transmission systems. To better understand the nonlinear distortion, modeling an essential technology. Most of current models focus on statistical characteristics noise. In this paper, we investigate analytical that predict time-varying noise waveform. For return-to-zero (RZ) pulse-shaped system, “power weighted, additive-multiplicative model” investigated under various system conditions for quadrature phase shift...

We propose a new design for pilot based OSNR monitor with XPM noise exclusion at the receiver side. High accuracy and low nonlinear sensitivity (<0.5dB error) are proved by 1Tb/s superchannel transmission experiments.

The high complexity of conventional intra-channel nonlinearity compensation algorithms, such as back-propagation, is considered the major obstacle for implementation. To reduce complexity, perturbation analysis applied because it considers multi-span transmission one stage. In those based back-propagation (PBP) and pre-distortion, number required stage much less than that back-propagation. further, multi-tap finite impulse response filter (FIR) in PBP replaced with one-tap infinite (IIR)...

Differential pilots aided in-band OSNR monitor is proposed and verified under 32GBaud WDM experiments. High accuracy (<0.5dB error), no dependency on pulse shapes, large nonlinear tolerance (1dB error after 4dBm 2700km transmission) are proved.

Performance problems in managed languages are extremely difficult to find. Despite many efforts find those problems, most existing work focuses on how debug a user-provided test execution which performance already manifest. It remains largely unknown effectively bugs before software release. As result, often escape production runs, hurting reliability and user experience. This paper describes PerfBlower, general testing framework that allows developers quickly Java programs memory-related...

C+L-band optical networks suffer from transmission impairments including amplified spontaneous emission noise and Kerr-induced stimulated-Raman-scattering-induced nonlinear interference. The generalized signal-to-noise ratio (GSNR) profiles across different links of the network play a crucial role in determining overall traffic load operating margins, but GSNR is highly dependent on signal power along link time-varying channel-loading conditions, particularly for future dynamic mesh...

There has been a lot of effort in our industry to develop analytical and numerical models for accurate estimation quality transmission (QoT), which is essential efficiently design operate optical transport networks. However, most researchers do not have access real network data validate improve their models. We provide from production on GitHub, hoping it can be some help community advance this area. This letter describes how use the open-source data.

Polarization-dependent loss (PDL) is regarded as a major distortion in dual-polarization coherent systems. Due to its statistical characteristics, time-consuming Monte Carlo simulation usually used evaluate penalty. In order accelerate the speed, more rapid method, reversed channel proposed and verified. Compared with simulation, for example 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> iterations, time reduced from 200 h 15 min,...

A high performance nonlinear compensator is proposed based on XPM model. It achieves 1.7 dB Q improvement with 80% complexity reduction. tolerates asynchronous process among multi-channels and the information interconnection speed far below baudrate.

Implementation-efficient nonlinear mitigation algorithms for digital coherent transceivers are introduced. Q-improvement by different algorithm combinations is presented transmission scenarios. Expectations on further improvement thorough noise reshaping and cycle slip reduction also addressed.

With proper phase rotation on perturbation terms, the enhanced intra-channel nonlinearity pre-distortion was proposed and demonstrated. The experiment shows that 1dB improvement is achieved performance even better than back-propagation for RZ format.

The flow table in OpenFlow switches plays a critical role OpenFlow-based Software Defined Networking (SDN), which stores the rules populated by controllers for controlling and directing packet flows SDN. limited capacity of becomes performance bottleneck SDN new target malicious attacks, as well. This paper analyzes timeout impact on proposes Dynamic LRU entry rule eviction algorithm to mitigate overflow improve performance.