47 research outputs found
Classifying the factors affecting the adoption of the SDN-microSENSE innovations
No full textThis paper presents the results of a survey conducted in order to identify the most critical factors that can affect the market adoption of the innovations developed in the H2020 R&I project SDN-microSENSE. A hierarchy of the main criteria and sub-criteria was created using the Fuzzy Analytical Hierarchy Process method and experts in the area expressed their preferences through a web-based survey. The results of this process provide an insight on the expert's vision regarding the importance of the factors that are crucial for the adoption of cyber-security solution in the Electrical Power and Energy Systems domain
Accurate estimation of the impact of IP traffic burstiness on the performance of wavelength division multiplexing networks
No full textFour-wave mixing and in-band crosstalk noise can limit the performance of wavelength division multiplexing optical networks. The statistics of these noises depend on the nature of the traffic. In this paper, the performance of an IP over MP lambda S-based network is analyzed using the Multi-Canonical Monte Carlo ( MCMC) method and it is shown that the Gaussian approximation does not yield accurate results. The importance of the traffic load and the traffic distribution in the optical channels is also investigated. It is shown that a proper traffic distribution in the optical channels, can improve the performance of the network. (c) 2005 Optical Society of America
The emergence of operator-neutral small cells as a strong case for cloud computing at the mobile edge
No full textSmall cells have emerged as a useful tool for supporting increased network capacity through network densification, but they can also be used to support edge cloud computing services. In this paper, we provide a preview of an innovative concept that tackles the consolidation of multi-tenancy in such type communications infrastructures, as well as the placement of network intelligence and applications in the network edge. After surveing the challenges and the enabling technologies, we present the envisaged architecture to manage and control the Cloud-Enabled Small Cell infrastructure. Also, at the operation level, we explain the potential advantages of adopting the proposed solutions on the long-term evolution access network
Modeling gender evolution and gap in science and technology using ecological dynamics
No full textIn this paper a model based on population biology is proposed in order to investigate the evolution of human resources (men and women) in science and technology as a share of labor market as well as the dynamics of their gap. An analytical and a simulation method using the Artificial Bee Colony optimization algorithm are described and used for the determination of the proposed model parameters. The presented model is applied to three case studies; Greece, Portugal and Europe-27.3 The accuracy of the obtained results is confirmed through comparison with actual data. In addition, the model can also be used to accurately forecast future trends. It is illustrated that the gender gap is continuously decreasing, while in the last years, women seem to outperform men in the field of science and technology. The estimation and forecasting ability of the model can be used as an extremely valuable tool for decision and policy makers. © 2012 Elsevier Ltd. All rights reserved
Nonlinearity tolerance of optical modulation formats in nonzero dispersion fibers
No full textThis letter addresses the issue of the choice of optical modulation format in a multipan wavelength-division-multiplexing system using G.655 fiber. Various modulation formats are assessed by numerical simulation in the presence of fiber nonlinearities with four-wave mixing being the dominant effect. It is shown that the various amplitude modulation alternatives result in more or less the same performance. Phase modulation schemes such as differential phase-shift keying drastically increase the system performance leading to an increase of the Q-factor by almost 3 dB. © 2005 IEEE
Modeling Complex Telecom Investments: A System of Systems Approach
No full textThis paper presents a complex telecom investment problem analysis using system of systems concepts. This is necessary due to problem's multidimensional nature with several interdependences, and the presence of uncertainty and competition. A genetic algorithm is implemented in MATLAB in order to optimize the objective function (operator's profitability) of the formulated nonlinear programming problem. This approach is capable of providing optimal policies (regarding, e.g., services pricing, inception of investment, or revenues reinvestment) in a competitive market helping future investors in decision making by using various emulated strategic plans as reference. © 1988-2012 IEEE
Multicanonical Monte Carlo modeling of wavelength division multiplexed differential phase shift keying systems
No full textDifferential phase shift keying (DPSK) modulation is being considered as a possible candidate for future optical wavelength division multiplexed (WDM) transmission systems. In a single channel link, the balanced interferometric DPSK receiver exhibits increased tolerance against amplified spontaneous emitting (ASE) noise and fiber nonlinear effects. In this paper, a model is presented that can be used to estimate the performance of a multichannel DPSK system taking into account the influence of interchannel phenomena, namely cross-phase modulation (XPM) and four wave mixing (FWM), in the phase noise statistics. The model is based on an approximate solution of the fiber propagation equation and the multicanonical Monte Carlo (MCMC) method. It provides an efficient tool that can be used to investigate the influence of many link design parameters such as channel spacing, launch power, and fiber dispersion. The model is illustrated in the comparison of the performance of multichannel DPSK to on-off keying (OOK) systems. It is verified that, even in the presence of interchannel effects, DPSK modulation greatly enhances the system performance compared to OOK. © 2009 IEEE
Optical delay lines based on soliton propagation in photonic crystal coupled resonator optical waveguides
No full textIn this paper, a study of optical delay lines based on soliton propagation in coupled resonator optical waveguides is performed. For a given bit rate and required delay, design equations are given that relate the soliton peak power and collision period to the soliton width. To study the influence of higher order linear and nonlinear dispersion, a continuous wave propagation model incorporating these effects is also derived. Using this model, the soliton stability in the presence of higher order dispersion, optical loss and adjacent soliton pulses is numerically verified. It is also shown that soliton-based delay lines can achieve nanosecond delay at a propagation length of a few millimeters due to the high slow down factors that can be obtained. © 2007 IEEE
A system of systems framework for the reliability assessment of telecommunications networks
No full textIn this paper, a system of systems (SoS) framework for the reliability analysis of telecommunication networks is proposed. In this framework, two hazard analysis techniques, hazard and operability analysis and fault tree analysis, are combined in a hybrid scheme. This is further enhanced using the Bayesian network model along with sensitivity analysis in order to answer complex probability queries and to estimate the impact of residual mishap risks, unknown events, or events that cannot easily be modeled. The SoS emergent behavior is further revealed using exploratory modeling. The proposed SoS framework is applied in the case of a fiber-to-the-curb VDSL telecommunication network. © 2007-2012 IEEE
