摘要：Transparent optical-fiber based transmission and networking with transmission capacity of Terabit/s per optical fibre have revolutionized modern telecommunications and consequently have influenced dramatically the working methods and everyday life of societies and individuals. The ongoing research and development efforts in this extremely innovative field are reflected in this Special Issue on Transparent Optical Networking which contains nine carefully selected papers based on the contributions to the 12th International Conference on Transparent Optical Networks ICTON 2010, Munich, Germany, June 27- July 1, 2010, www.itl.waw.pl/icton. ICTON is receiving technical co-sponsorship by the IEEE Photonics Society (formerly LEOS). All papers in this Special Issue have been submitted by Editors’ invitations. The first paper entitled Design Considerations and Performance Comparison of High-Order Modulation Formats using OFDM by A. Ali, J. Leibrich, and W. Rosenkranz, addresses OFDM transmission over optical links with high spectral efficiency. 32*10.7 Gb/s optical WDM-OFDM over 3200km SSMF with direct detection are achieved. The second paper on the Dimensioning of Optical Codes in OCDM/WDM Optical Packet Switches by V. Eramo, L. Piazzo, A. Germoni, A. Cianfrani, and M. Listani, investigates the performance of an Optical Code Division Multiplexing/Wavelength Division Multiplexing (WDM/OCDM) Optical Packet Switch when impairments due to both Multiple Access Interference and Beat noise are taken into account. A Packet Loss Probability of the OCDM/WDM switch of 10−9 is demonstrated when M=16 wavelengths, Gold code of length L=511 and only 24 wavelength converters are used in the switch. The third paper on the Performance of Stereo Multiplexing in Single Channel and DWDM Systems Using Direct Detection with Optimum Dispersion maps by O. Gaete, L. Coelho and B. Spinnler, compares the performance of Stereo Multiplexing, a novel technique that permits simultaneous direct detection of two modulated optical carriers, with single-carrier DQPSK and dual carrier DQPSK for single channel and DWDM transmission of 55.5 Gb/s through 1040 km of SMF. It is shown that the best performance and robustness is obtained by sharing the information between two carriers, Stereo being only 1dB below dual-carrier NRZDQPSK. The fourth paper on Adaptive Data Rates for Flexible Transceivers in Optical networks by B. Teipen, M. H. Eiselt, K. Grobe, J.-P. Elbers, discusses possibilities and advantages of reconfigurable and dynamically-adaptive transceivers, and their potential applications in future optical networks. These software-defined transceiver configurations support a set of specific modulation formats, with corresponding data rates and tolerances to system impairments, as well as sets of electronic digital signal processing schemes chosen to best function in a given network environment The fifth paper entitled Optimization Framework for Supporting 40 Gbit/s and 100Gbit/s Services over Heterogeneous Optical Transport Networks by J. Santos, J. Pedro, P. Monteiro, and J. Pires presents a novel hybrid optimization framework, which is based on an iterative combination of linear programming and rounding algorithms for the demand routing, with graph coloring heuristics for the wavelength assignment. The performance of this framework is assessed and compared with a similar approach that resorts to an integer linear programming (ILP) model to route the demands. The sixth paper entitled Scalability Analysis of Optical Intrasystem Interconnects by S. Aleksić and N. Ferhatović investigates requirements and limitations of large-scale optical interconnects. Various point-to-point interconnects and two optically switched interconnection options were studied with regard to their scalability by considering various impairments on the optical signal, required number of fiber links and power consumption. The seventh paper addresses Heuristic Approaches for Periodic Reconfiguration of Lightpath-based Networks under Multi-hour Traffic. Authors are R. Aparicio-Pardo, B. Garcia-Manrubia, N. Skorin-Kapov, and P. Pavon- Marino. This paper presents and compares two algorithms for planning a reconfigurable virtual topology suitable for exploring the trade-off between lower network costs obtained through better resource allocation and undesired traffic disruptions. The merits of both algorithms are assessed for moderate network sizes through comparison with analytical lower bounds and exact solutions obtained by a MILP formulation. The eighth paper entitled Delay-Constrained Admission and Bandwidth Allocation for Long-Reach EPON by B. Kantarci and H. T. Mouftah presents a delay-constrained admission control mechanism and adapts this scheme to a previously proposed bandwidth allocation technique, called Delay-Constrained Periodic GATE Optimization (DC-PGO). Through simulations it is shown that DC-PGO enhances the performance of multithreaded polling in long-reach Ethernet PON when packets of differentiated service classes arrive with prespecified delay requirements. The ninth paper entitled Energy Efficient Optical Networks with Minimized Non-renewable Power Consumption by X. Dong, T. El-Gorashi and J. M. H. Elmirghani introduces a Linear Programming (LP) model and a novel heuristic to minimize the non-renewable power consumption in the “hybrid-power” IP over WDM network. The performance of the network is studied considering two topologies, the NSFNET and the USNET. Compared with routing in the electronic layer, the results show that routing in the optical layer coupled with using renewable energy significantly reduces the CO2 emissions of the IP over WDM network by up to 73% for the NSFNET and 69% for the USNET.
