For all optical Wavelength Division Multiplexing (WDM) network based on G.653 fibers, we investigate the quality factor deterioration due to combined nonlinear effects and Amplified spontaneous emission (ASE) noise fo...For all optical Wavelength Division Multiplexing (WDM) network based on G.653 fibers, we investigate the quality factor deterioration due to combined nonlinear effects and Amplified spontaneous emission (ASE) noise for system parameters based on ITU-T Recommendation G.692. The investigation: (a) emphasizes on stimulated Raman scattering (SRS) and four wave mixing (FWM) effects which are the dominant nonlinearities known to limit WDM system performance and (b) accounts for beating between nonlinearities and beating between ASE noise and nonlinearities. Using the proposed model, performance of the worst affected channels due to SRS and FWM is compared and the results indicate that the worst affected channel due to SRS performs better and hence must be preferred for reliable and efficient transmission over the worst affected channel due to FWM. Further, the results suggest that to achieve a desired error rate (quality factor);there exists an optimal value of channel spacing for a given number of channels. The proposed theoretical model is also validated through extensive simulations over Rsoft OptSimTM simulator and the two sets of results are found to match, indicating that the proposed model accurately calculates the quality factor of the all optical WDM network.展开更多
In a translucent network scenario, development of an optical control plane (OCP) that is aware of the location and number of available regenerators and all-optical wavelength converters (AOWCs) is of paramount importa...In a translucent network scenario, development of an optical control plane (OCP) that is aware of the location and number of available regenerators and all-optical wavelength converters (AOWCs) is of paramount importance. However, current generalized multiprotocol label switching (GMPLS) protocol suite does not consider the distribution of regenerator and AOWC availability information to all the network nodes. In this paper, we propose a novel optical control plane (OCP) architecture that 1) disseminates information about network components (i.e. regenerators and AOWCs) to all the network nodes, and 2) evaluates candidate routes which use fewest amounts of network components. Performance of the proposed OCP is compared with a recently proposed hybrid OCP approach in terms of blocking performance, number of deployed components and lightpath establishment setup times. The obtained simulation results show that the proposed OCP approach demonstrates low connection blocking and establishes lightpaths by 1) minimizing the overall network cost owing to the deployment of minimum total number of network components, and 2) demonstrating acceptable lightpath establishment setup times at all traffic loads. Further, the proposed OCP methodology is compatible and suitable for controlling the operations of a novel electro-optical hybrid translucent node which is a latency efficient technology capable of delivering a cost effective implementation suitable for large scale deployment.展开更多
In this paper, we contrive a model that underpins the offline Physical Layer Impairment-Routing and Wavelength Assignment (PLI-RWA) issue in translucent networks. We introduce an innovative PLI-Signal Quality Aware RW...In this paper, we contrive a model that underpins the offline Physical Layer Impairment-Routing and Wavelength Assignment (PLI-RWA) issue in translucent networks. We introduce an innovative PLI-Signal Quality Aware RWA (PLI-SQARWA) algorithm that (a) guarantees zero blocking due to signal degradation and wavelength contention and (b) aims at minimizing the total required number of network components i.e. regenerators and all-optical wavelength converters (AOWCs). Further, in view of reducing the time delay due to optical-electrical-optical (OEO) conversions, we propose a novel electro-optical hybrid translucent node architecture. We show that PLI-SQARWA outperforms a recent heuristic for RWA and regenerator placement (RP) in terms of capital expenditure (CapEx) and time delay;while demonstrating superior blocking performance at all traffic loads. In addition, at high traffic loads, PLI-SQARWA also starts to provision savings on operational expenditure (OpEx). We proceed to the performance comparison of network equipped with the proposed hybrid node and existing translucent and transparent node architectures. The results clearly show that use of the hybrid node incurs less time delay at a similar blocking performance shown by nodes which use OEO conversion for both, regeneration and/or wavelength conversion. The results presented also highlight the significance of equipping the PLI-RWA routing phase with signal quality awareness in order to reduce the network component count and the use of AOWCs to minimize time delay due to OEO conversions.展开更多
With the steady growth of traffic volume in core networks,it is predicted that future optical network communication will be constrained mainly by cost and power consumption.Thus,for Internet sustainability,it will be ...With the steady growth of traffic volume in core networks,it is predicted that future optical network communication will be constrained mainly by cost and power consumption.Thus,for Internet sustainability,it will be necessary to ensure cost and power efficiency in optical networks.The aims of this study are(i)to identify the main sources of cost and power consumption in fixed-grid(SLR and MLR)and flexi-grid(OFDM)optical networks,and(ii)to compare techniques for improving cost and power efficiency in SLR/MLR-and OFDM-based networks.To this end,we conducted a comparative analysis of cost and power efficiency for the OFDM-and MLR/SLR-based networks,and considering realistic networks,evaluated the cost and power consumed by different components in the optical layer.Our results show that(i)OFDM-based networks outperform those based on MLR/SLR in terms of both cost and power-efficiency,(ii)the extra equipment cost incurred due to under-utilization of spectrum is reduced by switching to a flexi-grid network,(iii)lower power consumption per bit is obtained when the networking solution ensures a finer bit-rate granularity,and(iv)there exists a power and spectrum minimization trade-off that is network characteristic dependent.展开更多
The tremendous and consistent increase in the volume and heterogeneity of traffic has resulted in major innovations in the telecommunication networks.In regard to the optical networks,existing studies have shown that ...The tremendous and consistent increase in the volume and heterogeneity of traffic has resulted in major innovations in the telecommunication networks.In regard to the optical networks,existing studies have shown that by adopting a mixed line rate(MLR)strategy,the wavelength division multiplexed optical networks can cost-effectively respond to the diverse variety of traffic requirements which have heterogeneous service demands.Unlike existing studies which focus on various MLR network issues by considering deployment of the standard single mode fiber only within the network,in the current work,we investigate the signal quality deterioration due to the combined effects of dominant physical layer impairments for an MLR optical network conforming to the various ITU-T compliant fibers and also considering the optical frequency grid based on ITU-T Recommendation G.692.The main aim of our current study is to identify,for a given fiber,the modulation format configuration which provides the highest performance.We conduct extensive simulations on the considered MLR system using the obtained optimum channel spacing values between the single and mixed line rates.Our results show that the existence of 10 Gbit/s line rate has a detrimental effect on the 40 Gbit/s and/or 100 Gbit/s line rate;however,the 40 Gbit/s and/or 100 Gbit/s line rate’s effect on a 10 Gbit/s line rate is not so detrimental,as well as between the similar line rates.Overall,our results clearly show that choice of the line rate of both,the central channel and its adjacent channels,has a major effect on the MLR network performance.展开更多
文摘For all optical Wavelength Division Multiplexing (WDM) network based on G.653 fibers, we investigate the quality factor deterioration due to combined nonlinear effects and Amplified spontaneous emission (ASE) noise for system parameters based on ITU-T Recommendation G.692. The investigation: (a) emphasizes on stimulated Raman scattering (SRS) and four wave mixing (FWM) effects which are the dominant nonlinearities known to limit WDM system performance and (b) accounts for beating between nonlinearities and beating between ASE noise and nonlinearities. Using the proposed model, performance of the worst affected channels due to SRS and FWM is compared and the results indicate that the worst affected channel due to SRS performs better and hence must be preferred for reliable and efficient transmission over the worst affected channel due to FWM. Further, the results suggest that to achieve a desired error rate (quality factor);there exists an optimal value of channel spacing for a given number of channels. The proposed theoretical model is also validated through extensive simulations over Rsoft OptSimTM simulator and the two sets of results are found to match, indicating that the proposed model accurately calculates the quality factor of the all optical WDM network.
文摘In a translucent network scenario, development of an optical control plane (OCP) that is aware of the location and number of available regenerators and all-optical wavelength converters (AOWCs) is of paramount importance. However, current generalized multiprotocol label switching (GMPLS) protocol suite does not consider the distribution of regenerator and AOWC availability information to all the network nodes. In this paper, we propose a novel optical control plane (OCP) architecture that 1) disseminates information about network components (i.e. regenerators and AOWCs) to all the network nodes, and 2) evaluates candidate routes which use fewest amounts of network components. Performance of the proposed OCP is compared with a recently proposed hybrid OCP approach in terms of blocking performance, number of deployed components and lightpath establishment setup times. The obtained simulation results show that the proposed OCP approach demonstrates low connection blocking and establishes lightpaths by 1) minimizing the overall network cost owing to the deployment of minimum total number of network components, and 2) demonstrating acceptable lightpath establishment setup times at all traffic loads. Further, the proposed OCP methodology is compatible and suitable for controlling the operations of a novel electro-optical hybrid translucent node which is a latency efficient technology capable of delivering a cost effective implementation suitable for large scale deployment.
文摘In this paper, we contrive a model that underpins the offline Physical Layer Impairment-Routing and Wavelength Assignment (PLI-RWA) issue in translucent networks. We introduce an innovative PLI-Signal Quality Aware RWA (PLI-SQARWA) algorithm that (a) guarantees zero blocking due to signal degradation and wavelength contention and (b) aims at minimizing the total required number of network components i.e. regenerators and all-optical wavelength converters (AOWCs). Further, in view of reducing the time delay due to optical-electrical-optical (OEO) conversions, we propose a novel electro-optical hybrid translucent node architecture. We show that PLI-SQARWA outperforms a recent heuristic for RWA and regenerator placement (RP) in terms of capital expenditure (CapEx) and time delay;while demonstrating superior blocking performance at all traffic loads. In addition, at high traffic loads, PLI-SQARWA also starts to provision savings on operational expenditure (OpEx). We proceed to the performance comparison of network equipped with the proposed hybrid node and existing translucent and transparent node architectures. The results clearly show that use of the hybrid node incurs less time delay at a similar blocking performance shown by nodes which use OEO conversion for both, regeneration and/or wavelength conversion. The results presented also highlight the significance of equipping the PLI-RWA routing phase with signal quality awareness in order to reduce the network component count and the use of AOWCs to minimize time delay due to OEO conversions.
文摘With the steady growth of traffic volume in core networks,it is predicted that future optical network communication will be constrained mainly by cost and power consumption.Thus,for Internet sustainability,it will be necessary to ensure cost and power efficiency in optical networks.The aims of this study are(i)to identify the main sources of cost and power consumption in fixed-grid(SLR and MLR)and flexi-grid(OFDM)optical networks,and(ii)to compare techniques for improving cost and power efficiency in SLR/MLR-and OFDM-based networks.To this end,we conducted a comparative analysis of cost and power efficiency for the OFDM-and MLR/SLR-based networks,and considering realistic networks,evaluated the cost and power consumed by different components in the optical layer.Our results show that(i)OFDM-based networks outperform those based on MLR/SLR in terms of both cost and power-efficiency,(ii)the extra equipment cost incurred due to under-utilization of spectrum is reduced by switching to a flexi-grid network,(iii)lower power consumption per bit is obtained when the networking solution ensures a finer bit-rate granularity,and(iv)there exists a power and spectrum minimization trade-off that is network characteristic dependent.
文摘The tremendous and consistent increase in the volume and heterogeneity of traffic has resulted in major innovations in the telecommunication networks.In regard to the optical networks,existing studies have shown that by adopting a mixed line rate(MLR)strategy,the wavelength division multiplexed optical networks can cost-effectively respond to the diverse variety of traffic requirements which have heterogeneous service demands.Unlike existing studies which focus on various MLR network issues by considering deployment of the standard single mode fiber only within the network,in the current work,we investigate the signal quality deterioration due to the combined effects of dominant physical layer impairments for an MLR optical network conforming to the various ITU-T compliant fibers and also considering the optical frequency grid based on ITU-T Recommendation G.692.The main aim of our current study is to identify,for a given fiber,the modulation format configuration which provides the highest performance.We conduct extensive simulations on the considered MLR system using the obtained optimum channel spacing values between the single and mixed line rates.Our results show that the existence of 10 Gbit/s line rate has a detrimental effect on the 40 Gbit/s and/or 100 Gbit/s line rate;however,the 40 Gbit/s and/or 100 Gbit/s line rate’s effect on a 10 Gbit/s line rate is not so detrimental,as well as between the similar line rates.Overall,our results clearly show that choice of the line rate of both,the central channel and its adjacent channels,has a major effect on the MLR network performance.
