A multipopulation parallel genetic simulated annealing based QoS routing and wavelength assignment integration algorithm for multicast in optical networks

Copyright @ 2008 Elsevier B.V. All rights reserved.In this paper, we propose an integrated Quality of Service (QoS) routing algorithm for optical networks. Given a QoS multicast request and the delay interval specified by users, the proposed algorithm can find a flexible-QoS-based cost suboptimal routing tree. The algorithm first constructs the multicast tree based on the multipopulation parallel genetic simulated annealing algorithm, and then assigns wavelengths to the tree based on the wavelength graph. In the algorithm, routing and wavelength assignment are integrated into a single process. For routing, the objective is to find a cost suboptimal multicast tree. For wavelength assignment, the objective is to minimize the delay of the multicast tree, which is achieved by minimizing the number of wavelength conversion. Thus both the cost of multicast tree and the user QoS satisfaction degree can approach the optimal. Our algorithm also considers load balance. Simulation results show that the proposed algorithm is feasible and effective. We also discuss the practical realization mechanisms of the algorithm.This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1, the National Natural Science Foundation of China under Grant nos. 60673159 and 70671020, the National High-Tech Research and Development Plan of China under Grant no. 2006AA01Z214, Program for New Century Excellent Talents in University, and the Key Project of Chinese Ministry of Education under Grant no. 108040

Enhanced WDM-OFDM-PON System Based on Higher Data Transmitted with Modulation Technique

ABSTRACT:- Studies among the field communication system existing technique and proposes and by experimentation demonstrate a multiuser wavelengthdivision-multiplexing passive optical network (WDM-PON) system combining with orthogonal frequency division multiple (OFDM) technique. A tunable multiwavelength optical comb is intended to provide flat optical lines for helping the configuration of the multiple source-free optical network units WDM-OFDM-PON system supported normal single-mode fiber (SSMF). In WDM based on fiber, optical network communications using wavelength with multiplex or demultiplex may be a technology that multiplexes a variety of optical carrier signals onto one fiber by victimization completely different wavelengths of optical device lightweight. this system allows bidirectional communications over one strand of fiber, also as multiplication of capability and calculate BER (Bit Error Rate) and OSNR (optical signal noise ratio) finally; a comparison of by experimentation achieved receiver sensitivities and transmission distances victimization these receivers is given. The very best spectral potency and longest transmission distance at the very best bit rate. WDM based applications like transmission data, medical imaging data, and digital audio data and video conferencing data are information measure-intensive with the Advance in optical technology providing verdant bandwidth, it's natural to increase the multicast construct to optical networks so as to realize increased performance. Our projected scheme (PGA) based on information load transmitted capability improve supported higher information transmitted over these channels and high data up to develop in Matlab tool and using optical Interleaved the OFDM model and analysis the performance of the WDM-PON system

IP multicast over WDM networks

Ph.DDOCTOR OF PHILOSOPH

Multicast protection and energy efficient traffic grooming in optical wavelength routing networks.

Zhang, Shuqiang.Thesis (M.Phil.)--Chinese University of Hong Kong, 2010.Includes bibliographical references (p. 74-80).Abstracts in English and Chinese.Abstract --- p.i摘要 --- p.ivAcknowledgements --- p.vTable of Contents --- p.viChapter Chapter 1 --- Background --- p.1Chapter 1.1 --- Routing and Wavelength Assignment --- p.1Chapter 1.2 --- Survivability in Optical Networks --- p.3Chapter 1.3 --- Optical Multicasting --- p.4Chapter 1.3.1 --- Routing and Wavelength Assignment of Optical Multicast --- p.5Chapter 1.3.2 --- Current Research Topics about Optical Multicast --- p.8Chapter 1.4 --- Traffic Grooming --- p.10Chapter 1.4.1 --- Static Traffic Grooming --- p.11Chapter 1.4.2 --- Dynamic Traffic Grooming --- p.13Chapter 1.5 --- Contributions --- p.15Chapter 1.5.1 --- Multicast Protection with Scheduled Traffic Model --- p.15Chapter 1.5.2 --- Energy Efficient Time-Aware Traffic Grooming --- p.16Chapter 1.6 --- Organization of Thesis --- p.18Chapter Chapter 2 --- Multicast Protection in WDM Optical Network with Scheduled Traffic --- p.19Chapter 2.1 --- Introduction --- p.19Chapter 2.2 --- Multicast Protection under FSTM --- p.22Chapter 2.3 --- Illustrative Examples --- p.28Chapter 2.4 --- Two-Step Optimization under SSTM --- p.37Chapter 2.5 --- Summary --- p.40Chapter Chapter 3 --- Energy Efficient Time-Aware Traffic Grooming in Wavelength Routing Networks --- p.41Chapter 3.1 --- Introduction --- p.41Chapter 3.2 --- Energy consumption model --- p.43Chapter 3.3 --- Static Traffic Grooming with Time awareness --- p.44Chapter 3.3.1 --- Scheduled Traffic Model for Traffic Grooming --- p.44Chapter 3.3.2 --- ILP Formulation --- p.44Chapter 3.3.3 --- Illustrative Numerical Example --- p.48Chapter 3.4 --- Dynamic Traffic Grooming with Time Awareness --- p.49Chapter 3.4.1 --- Time-Aware Traffic Grooming (TATG) --- p.51Chapter 3.5 --- Simulation Results of Dynamic Traffic Grooming --- p.54Chapter 3.5.1 --- 24-node USNET: --- p.55Chapter 3.5.2 --- 15-node Pacific Bell Network: --- p.59Chapter 3.5.3 --- 14-node NSFNET: --- p.63Chapter 3.5.4 --- Alternative Configuration of Simulation Parameters: --- p.67Chapter 3.6 --- Summary --- p.71Chapter Chapter 4 --- Conclusions and Future Work --- p.72Chapter 4.1 --- Conclusions --- p.72Chapter 4.2 --- Future Work --- p.73Bibliography --- p.74Publications during M.Phil Study --- p.8

単一もしくは混合フォーマット光ネットワークのための光ファイバの四光波混合を用いた光信号処理

As data rates in broadband optical networks continue to grow, all optical signal processing technologies are expected to become important for future high bit-rate communication systems to address the growing demand for network flexibility, low cost and high bandwidth. Along the line of the capacity increased, many new modulation formats have been introduced. The most straightforward format is on-off-keying (OOK) modulation format. The state of art reveals that the differential phase-shift keying (DPSK)modulation format is the best candidate for high-speed long haul network segment, while OOK is suitable for short reach network segment. However, the next generation transmission systems will more likely employ mixed modulation formats. Thus, the shift towards these changes to be applied in many applications is necessary. Hence, it is worth investigating several signal processing, not only by using a single modulation format but also mixed modulation formats. In order to realize such systems, the scheme requirement must be transparent to modulation format and bit-rate. One of the promising candidates is based on the third-order nonlinear susceptibility x(3) in a nonlinear fiber, which is also called four-wave mixing (FWM). Fiber-based FWM, in a highly nonlinear fiber (HNLF) is a preferable choice due to its fast nonlinear response and high conversion efficiency. FWM technique can be also be used as an all-optical AND logic gates and signal regenerator. In optical fiber communication systems, signal distortions due to chromatic dispersion in fiber dominantly limit transmission length and bit-rate. An improvement in the distorted signal is crucially needed, as the processed signal will become more degraded after some distance of transmission. Optical phase conjugation (OPC) and tunable dispersion compensation modulator (TDCM) are two attractive schemes used to increase the signal robustness in transmission systems. It is also desirable if a practical function such as flexible picosecond width-tunability can be accomplished. The advantageous of flexible converted pulse width are for the creation of higher bit-rate signals and the ability to support wider bandwidth requirements. In this thesis, the experimental demonstration using compressed RZ clock from Raman adiabatic-soliton compressor (RASC) and continuous wave (CW) signal as a pump signals in all-optical fiber-based FWM AND-gate using singleand mixed OOK-DPSK modulation formats in many applications can be realised. The applications including: all-optical nonreturn-to-zero(NRZ)-to-return-to-zero(RZ) wavelength-waveform conversions, all optical wave-length multicasting, all channel OTDM demultiplexing, and transmission performance between the midspan of OPC and TDCM. We experimentally demonstrated an all-optical NRZ-DPSK-to-RZ-DPSK waveform-wavelength conversion with flexible picosecond width-tunability and signal regeneration with reshaping functionality. The scheme is based on a RASC and a fiber-based AND-gate. In the first demonstration, we demonstrate waveform-wavelength conversion of a 10-Gb/s DPSK signal without input signal degradation over wide input-output wavelength ranges. The measurement results of the converted RZ-DPSK signal are pedestal-free, and its converted pulse width can be adjusted by tuning the Raman pump power in RASC. Further investigation of the regenerative properties due to chromatic dispersion is conducted at several Raman pump power settings over 40-km standard single-mode fibers (SSMFs) without dispersion compensation. Also, low power penalty with an error-free operation is obtained for the RZ-DPSK regenerated converted signal. Next, an all-optical 1-to-6 wavelength multicasting of a 10-Gb/s picosecond-tunable-width converted OOK data signal using a parametric pulse source from a RASC is experimentally demonstrated. Width-tunable wavelength multicasting within the C-band with approximately 40.6-nm of separation with various compressed RZ data signal inputs has been proposed and demonstrated. The converted multicast pulse widths can be flexibly controlled down by tuning the Raman pump powers of the RASC. Nearly equal pulse widths at all multicast wavelengths are obtained. Furthermore, wide open eye patterns and low power penalties at the 10??9 BER level are found. An all-optical demultiplexing of 40-Gb/s hybrid OTDM mixed format channels by using RASC-flexible control-window is also demonstrated. Error-free operations with less than 1.3-dB power penalties were obtained and this scheme is expected to be scalable toward higher bit-rates. Further demonstration related to NRZ-to-RZ waveform-wavelength conversion for 4 x 10-Gb/s multichannel mixed OOK-DPSK data formats, deploying a single FWM and RASC has been done. The fiber-based switch in HNLF based on parametric process between mixed data signals and the compressed RZ clock from RASC. By flexibly tuning the Raman pump power from RASC in between 0.20 and 0.90 W, high quality converted signal can be achieved. Bit-error-rate measurements show negative power penalties for the obtained RZ signals with pedestal-free pulses. Finally, we demonstrated the transmission performance between the midspan of TDCM and OPC schemes with specialty using multichannel-mixed OOK and DPSK format. The OPC scheme has the advantage over the penalties performance compared to TDCM scheme.電気通信大学201

A survey of optical multicast over WDM networks

Multicast applications such as multimedia, medical imaging, digital audio and video conferencing are bandwidth-intensive. With the advance in optical technology providing abundant bandwidth, it is natural to extend the multicast concept to optical networks in order to gain enhanced performance. This paper provides a comprehensive review of optical multicast techniques, covering the main optical multicast concept, the optical multicast switches, the multicast over single-hop broadcast-and-select networks, the multicast over multi-hop wide area mesh networks, and the related challenging algorithms developed for multicast routing in the optical domain