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At present days, metropolitan and access communication networks are markedly developing utilizing a variety of technologies. Their bearer communication infrastructures will be mostly exploiting the optical transmission medium where wavelength division multiplexing techniques will play a key role. Wavelength-Division Multiplexed Passive Optical Networks (WDM-PON) attract considerable attention for the next generation optical metropolitan and access networked systems. Simultaneously, the utilization of common optical network resources in wavelength domains will be more important. The main purpose of this paper is presented by the evaluation of resource efficiencies for the non-symmetric dynamic wavelength allocation method applied in the WDM-PON network design with a conventional topology. This contribution introduces a novel non-symmetric Dynamic Wavelength Allocation (DWA) method for a selected network design with the utilization only passive optical splitters in remote nodes. This novel wavelength allocation method is oriented on minimizing a number of working wavelengths that will be used for compliance of customers' requests for data transmitting in the common point-to-multipoint WDM–PON network design. For evaluation of wavelength scheduling, a simulation model related to the conventional WDM-PON network design is realized in the MATLAB programming environment is presented with results. Finally, different traffic loading scenarios are determined and, subsequently, resource efficiencies of the presented non-symmetric DWA method are evaluated from a viewpoint of application in future WDM-PON network designs. [ABSTRACT FROM AUTHOR]

A mathematical framework is presented to study the evolution of multi-point cumulants in nonlinear dispersive partial differential equations with random input data, based on the theory of weak wave turbulence (WWT). This framework is used to explain how energy is distributed among Fourier modes in the nonlinear Schrödinger equation. This is achieved by considering interactions among four Fourier modes and studying the role of the resonant, non-resonant, and trivial quartets in the dynamics. As an application, a power spectral density is suggested for calculating the interference power in dense wavelength-division multiplexed optical systems, based on the kinetic equation of the WWT. This power spectrum, termed the Kolmogorov-Zakharov (KZ) model, results in a better estimate of the signal spectrum in optical fiber, compared with the so-called Gaussian noise model. The KZ model is generalized to non-stationary inputs and multi-span optical systems. [ABSTRACT FROM PUBLISHER]

In this paper, the filtering properties of photonic crystals (PCs) to perform narrow-channel transmission-type filters in second and third optical fiber telecommunication windows have been studied. Filtration of these zero dispersion and low-loss windows have simultaneously been established by utilizing of a triple-cavity transmission-type one-dimensional PC that provides perfect transmittances and narrow-channels at corresponding wavelengths. Such PC-based optical filter can be used in wavelength division multiplexing (WDM) optical communications systems. [ABSTRACT FROM AUTHOR]

This paper presents a new passive optical network (PON) architecture that applies an optical multicast capable switch (OMS) to direct wavelengths to a set of PON branches and enables them to share the transceivers in the central office (CO) on demand. The OMS is composed of fiber splitters and switching gates, and by controlling the on-off gates the wavelengths at the inputs can reach any outputs of the OMS. Through the OMS configuration, logical PONs are dynamically formed according to changing traffic patterns, and traffic is further scheduled in the time domain within each logical PON. The proposed network achieves network resource sharing without requiring tunable transceivers or wavelength filters, and without changing deployed network devices in the field or at the user end. Analysis and experimental study results show the efficiency of resource sharing and demonstrate the concept of resource sharing among PON branches. [ABSTRACT FROM AUTHOR]

Abstract: In this investigation, we propose and experimentally demonstrate the remodulation technique using DPSK format in both downlink and uplink traffics with high extinction ratio (ER) in colorless WDM-PON; together with a simple self-restored architecture against fiber fault. Error free operation was achieved in a 20-km-reach 10-Gb/s WDM-PON without dispersion compensation. Comparison with other wavelength remodulation schemes for WDM-PONs is also performed, showing the proposed scheme can be a potential candidate for next generation wavelength reuse WDM-PONs. In addition, the performance of self-protection has also been discussed and analyzed. [Copyright &y& Elsevier]

Recently, metropolitan and access communication networks have markedly developed by utilizing a variety of technologies. Their bearer communication infrastructures will be mostly exploiting the optical transmission medium where wavelength division multiplexing techniques will play an important role. This contribution discusses the symmetric sharing of common optical network resources in wavelength and time domains. Wavelength-Division Multiplexed Passive Optical Networks (WDM-PON) attract considerable attention regarding the next generation of optical metropolitan and access networks. The main purpose of this contribution is presented by the analysis of possible scheduling of wavelengths for our novel hybrid network topologies considered for WDM-PON networks. This contribution briefly deploys adequate Dynamic Wavelength Allocation (DWA) algorithms for selected WDM-PON network designs with the provision of traffic protection when only passive optical components in remote nodes are utilized. The main part of this study is focused on the use of wavelength scheduling methods for selected WDM-PON network designs. For evaluation of offline and online wavelength scheduling for novel hybrid network topologies, a simulation model realized in the Matlab programming environment allows to analyze interactions between various metropolitan and access parts in the Optical Distribution Network (ODN) related to advanced WDM-PON network designs. Finally, wavelength scheduling methods are compared from a viewpoint of utilization in advanced WDM-PON networks designs. [ABSTRACT FROM AUTHOR]

Building on the Ethernet Passive Optical Network (EPON) and Gigabit PON (GPON) standards, Next-Generation (NG) PONs (i) provide increased data rates, split ratios, wavelengths counts, and fiber lengths, as well as (ii) allow for all-optical integration of access and metro networks. In this paper we provide a comprehensive probabilistic analysis of the capacity (maximum mean packet throughput) and packet delay of subnetworks that can be used to form NG-PONs. Our analysis can cover a wide range of NG-PONs through taking the minimum capacity of the subnetworks forming the NG-PON and weighing the packet delays of the subnetworks. Our numerical and simulation results indicate that our analysis quite accurately characterizes the throughput-delay performance of EPON/GPON tree networks, including networks upgraded with higher data rates and wavelength counts. Our analysis also characterizes the trade-offs and bottlenecks when integrating EPON/GPON tree networks across a metro area with a ring, a Passive Star Coupler (PSC), or an Arrayed Waveguide Grating (AWG) for uniform and non-uniform traffic. To the best of our knowledge, the presented analysis is the first to consider multiple PONs interconnected via a metro network. [ABSTRACT FROM AUTHOR]