262,552 research outputs found
Software defined transceivers for high-speed flexible optical networks
No full text"A novel high-capacity, energy-efficient and bit-rate flexible optical transceiver (Tx\/Rx), capable of supporting rates from 10Gb\/s to beyond 1Tb\/s, has been designed and its performance in long-haul transmission has been carefully investigated. The device can realize both orthogonal frequency division multiplexing (OFDM) and Nyquist wavelength division multiplexing (NWDM), for flexible super-channel generation; the inverse discrete Fourier transform (IDFT) and the discrete Fourier transform (DFT) are implemented directly in the optical domain, using a specially designed arrayed waveguide grating (AWG). Therefore, the transceiver can provide ultra-high capacity with significant improvements on the energy efficiency per transmitted bit. In addition, different modulation formats are possible, and different bit rates. In the present paper, we provide complete design guidelines of the AWG-based device that performs the IDFT\/DFT, evaluating the influence of the slab diffraction effect on the orthogonality of the subchannels. The complete functionality of the transceiver is numerically simulated and the influence of the noise from the inline amplifiers, chromatic dispersion, non-linear effects have been evaluated. In addition, to simplify the receiver architecture, a pulsed local oscillator is used for coherent balanced photodetection, and the impairments due to the phase noise have been investigated. The system performance is evaluated considering both bit error rate (BER) and the error vector magnitude (EVM) parameters.
Handbook of Optical Networks
No full textThis handbook is an authoritative, comprehensive reference on optical networks, the backbone of today’s communication and information society. The book reviews the many underlying technologies that enable the global optical communications infrastructure, but also explains current research trends targeted towards continued capacity scaling and enhanced networking flexibility in support of an unabated traffic growth fueled by ever-emerging new applications.
The book is divided into four parts: Optical Subsystems for Transmission and Switching, Core Networks, Datacenter and Super-Computer Networking, and Optical Access and Wireless Networks.
Each chapter is written by world-renown experts that represent academia, industry, and international government and regulatory agencies. Every chapter provides a complete picture of its field, from entry-level information to a snapshot of the respective state-of-the-art technologies to emerging research trends, providing something useful for the novice who wants to get familiar with the field to the expert who wants to get a concise view of future trends
Lightpath establishment in dynamic transparent optical networks assisted by end-to-end Quality of Transmission estimation
No full textDynamic Impairment-Aware Routing and Wavelength Assignment
No full textDynamic impairment-aware routing and wavelength assignment (IA-RWA) applies to dynamic core wavelength-division multiplexing (WDM) networks and refers to the process that is responsible for the computation of lightpaths (LPs) for traffic demands arriving during network operation. During this process, the effect of single-channel and multichannel impairments needs to be taken into account so as to compute LPs with strong quality of transmission (QoT) and not to disrupt the traffic that is already established in the network. In addition to ensuring acceptable QoT, the online application of IA-RWA seeks also to minimize the execution time needed per connection. Minimizing the LP setup time is critical during network operation, and the delay experienced due to the LP computation depends largely on the algorithmic implementation and particularly on the way physical-layer impairments (PLIs) are considered. Finally IA-RWA needs to be supported by a properly enhanced control plane that essentially enables the dynamic impairment-aware networking vision
All-fiberized dispersion-managed multi-channel regeneration at 43 Gb/s
No full textWe report on the simultaneous 2R regeneration of up to three 42.7 Gb/s wavelength-division-multiplexing channels in a simple dispersion-managed fiber section with signal quality improvements higher than 1.7 dB. The regenerator relies on self-phase modulation-induced spectral broadening of the optical channels inside the fiber section and subsequent bandpass filtering at shifted wavelengths, and it is experimentally investigated in single-, dual-, and three-channel operation using optical pulses of 33% duty cycle
Lightpath establishment in distributed GMPLS-controlled dynamic transparent optical networks using Quality of Transmission estimation
No full textNyquist-WDM-Based Flexible Optical Networks: Exploring Physical Layer Design Parameters
No full textWe focus on Nyquist-WDM-based flexible optical networks and examine the impact of introducing flexibility in physical layer design parameters on the network level performance. The considered physical layer parameters include the modulation format, the symbol-rate, the inter-subcarrier spacing, the inter-superchannel spacing, and the launch power. In order to examine the impact of allowing the symbol rate to be tuned on a super channel basis, three alternative launch power schemes are considered: (i) optimum launch power, (ii) constant launch power, and (iii) constant power spectral density. Case study results from a realistic reference core network highlight the identified trade-offs with respect to the utilized spectrum and the required transponders. It is shown that significant savings can be achieved by allowing the symbol rate to be dynamically tuned under different launch power options
Simultaneous processing of 43 Gb/s WDM channels by a fiber-based dispersion-managed 2R regenerator
No full textWe demonstrate 43 Gb/s multi-channel 2R regeneration in a single dispersion-managed fiber, based on SPM-induced spectral broadening and subsequent offset filtering
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