We propose an analytical model to evaluate the lightpath blocking performance for a single ROADM node with intra-node add/drop contention,in which the number of lightpaths that can be added/dropped with the same wavel...We propose an analytical model to evaluate the lightpath blocking performance for a single ROADM node with intra-node add/drop contention,in which the number of lightpaths that can be added/dropped with the same wavelength is limited by the add/drop contention factor.Different models of traffic load per nodal degree are considered to validate the effectiveness of the analytical model.The simulation results show that the proposed analytical model is effective in predicting the performance for different values of add/drop contention factor C and for variable offered loads at the node.The add/drop contention factor shows an important impact on the lightpath blocking performance and properly raising the contention factor can significantly improve the lightpath blocking performance.When the add/drop contention factor C exceeds a certain level,the performance of a ROADM with intra-node contention is close to that of a contentionless ROADM.展开更多
In wavelength division multiplexing (WDM) networks without wavelengthconversion functionality, we convert the dynamic routing and wavelength assignment problem formulti-lightpath demands to the edge-disjoint paths pro...In wavelength division multiplexing (WDM) networks without wavelengthconversion functionality, we convert the dynamic routing and wavelength assignment problem formulti-lightpath demands to the edge-disjoint paths problem, and propose a new algorithm. Thecomputer simulations show that the proposed algorithm has better blocking probability performancethan a sequential algorithm, which first separates a multi-lightpath demand into mutilplesingle-lightpath demands, then uses the fixed-alternate routing-first fit wavelength assignment(AR-FF) algorithm for each single-lightpath demand.展开更多
As all-optical networks grow with ever increasing ultra-high speed,the communication quality suffers seriously from physical layer impairments( PLIs). The same problem still exists in software defined optical network(...As all-optical networks grow with ever increasing ultra-high speed,the communication quality suffers seriously from physical layer impairments( PLIs). The same problem still exists in software defined optical network( SDON) controlled by OpenFlow. Aimed to solve this problem,a PLIs tolerance based lightpath provision scheme is proposed for OpenFlow controlled optical networks. This proposed approach not only takes the OSNR model to represent those linear PLIs factors,but also introduces those nonlinear factors into the OSNR model. Thus,the proposed scheme is able to cover most PLIs factors of each optical link and conduct optical lightpath provison with better communication quality. Moreover,PLIs tolerance model is also set up and considered in this work with some necessary extension to OpenFlow protocols to achieve better compatibility between physical layer impairments factors and various services connections. Simulation results show that the proposed scheme is able to get better performance in terms of packet loss rate and connection setup time.展开更多
In future optical transport networks,lightpath performance analysis is of great practical significance for fully automated management.In general,the quality of transmission(QoT)of lightpaths,measured by optical qualit...In future optical transport networks,lightpath performance analysis is of great practical significance for fully automated management.In general,the quality of transmission(QoT)of lightpaths,measured by optical quality factor or optical signal-to-noise ratio,has a complex time-varying process,along with the interactions of the other lightpath state parameters(LSPs),such as transmit power,chromatic dispersion,polarization mode dispersion.Current studies are mostly focused on lightpath QoT estimation,but ignoring lightpath-level data analytics.In this case,our article proposes a novel lightpath performance analysis method considering recurrence plot(RP)and cross recurrence plot(CRP).Firstly,we give a detailed interpretation on the recurrence patterns of LSPs via a qualitative 2-D RP representation and its quantitative measure.It can potentially enable the accurate and fast lightpath failure detection with a low computational burden.On the other hand,CRP is devoted to modeling the relationships between lightpath QoT and LSPs,and the correlation degree is determined by a geometric mean of multiple indexes of cross recurrence quantification analysis.From the view of application,such CRP analysis can provide the effective knowledge sharing to guarantee more credible QoT prediction.Extensive experiments on a real-world optical network dataset have clearly demonstrated the effectiveness of our proposal.展开更多
基金jointly supported by the National 863 Plans Project of China (2012AA050801)National Natural Science Foundation of China(NSFC)(61172057,61322109)+1 种基金Natural Science Foundation of Jiangsu Province(BK20130003)Science and Technology Support Plan of Jiangsu Province(BE2014855)
文摘We propose an analytical model to evaluate the lightpath blocking performance for a single ROADM node with intra-node add/drop contention,in which the number of lightpaths that can be added/dropped with the same wavelength is limited by the add/drop contention factor.Different models of traffic load per nodal degree are considered to validate the effectiveness of the analytical model.The simulation results show that the proposed analytical model is effective in predicting the performance for different values of add/drop contention factor C and for variable offered loads at the node.The add/drop contention factor shows an important impact on the lightpath blocking performance and properly raising the contention factor can significantly improve the lightpath blocking performance.When the add/drop contention factor C exceeds a certain level,the performance of a ROADM with intra-node contention is close to that of a contentionless ROADM.
基金Supported by the National High Technology Development 863 Program of China(2001AA122023)
文摘In wavelength division multiplexing (WDM) networks without wavelengthconversion functionality, we convert the dynamic routing and wavelength assignment problem formulti-lightpath demands to the edge-disjoint paths problem, and propose a new algorithm. Thecomputer simulations show that the proposed algorithm has better blocking probability performancethan a sequential algorithm, which first separates a multi-lightpath demand into mutilplesingle-lightpath demands, then uses the fixed-alternate routing-first fit wavelength assignment(AR-FF) algorithm for each single-lightpath demand.
基金Supported by the National High Technology Research and Development Programme of China(No.2012AA050804)
文摘As all-optical networks grow with ever increasing ultra-high speed,the communication quality suffers seriously from physical layer impairments( PLIs). The same problem still exists in software defined optical network( SDON) controlled by OpenFlow. Aimed to solve this problem,a PLIs tolerance based lightpath provision scheme is proposed for OpenFlow controlled optical networks. This proposed approach not only takes the OSNR model to represent those linear PLIs factors,but also introduces those nonlinear factors into the OSNR model. Thus,the proposed scheme is able to cover most PLIs factors of each optical link and conduct optical lightpath provison with better communication quality. Moreover,PLIs tolerance model is also set up and considered in this work with some necessary extension to OpenFlow protocols to achieve better compatibility between physical layer impairments factors and various services connections. Simulation results show that the proposed scheme is able to get better performance in terms of packet loss rate and connection setup time.
基金supported in part by the Science and Technology Project of Hebei Education Department,Grant ZD2021088in part by the S&T Major Project of the Science and Technology Ministry of China,Grant 2017YFE0135700。
文摘In future optical transport networks,lightpath performance analysis is of great practical significance for fully automated management.In general,the quality of transmission(QoT)of lightpaths,measured by optical quality factor or optical signal-to-noise ratio,has a complex time-varying process,along with the interactions of the other lightpath state parameters(LSPs),such as transmit power,chromatic dispersion,polarization mode dispersion.Current studies are mostly focused on lightpath QoT estimation,but ignoring lightpath-level data analytics.In this case,our article proposes a novel lightpath performance analysis method considering recurrence plot(RP)and cross recurrence plot(CRP).Firstly,we give a detailed interpretation on the recurrence patterns of LSPs via a qualitative 2-D RP representation and its quantitative measure.It can potentially enable the accurate and fast lightpath failure detection with a low computational burden.On the other hand,CRP is devoted to modeling the relationships between lightpath QoT and LSPs,and the correlation degree is determined by a geometric mean of multiple indexes of cross recurrence quantification analysis.From the view of application,such CRP analysis can provide the effective knowledge sharing to guarantee more credible QoT prediction.Extensive experiments on a real-world optical network dataset have clearly demonstrated the effectiveness of our proposal.
