An impairment-aware resource allocation scheme for dynamic elastic optical networks

By using impairment-driven variable guardbands, our proposed dynamic resource allocation scheme accommodates 50% more traffic in comparison to existing fixed transmission-reach- and guardband-based algorithms

Traffic-grooming- and multipath-routing-enabled impairment-aware elastic optical networks

Traffic grooming and multipath routing are two techniques that are widely adopted to increase the performance of traditional wavelength division multiplexed networks. They have been recently applied in elastic optical networks to increase spectral efficiency. In this study, we investigate the potential gains by jointly employing the two techniques in combination with a realistic physical impairment model. To allocate resources and quantify spectral efficiency gains over existing impairment-aware schemes, we present an analytical optimization formulation for small networks and a heuristic for large networks. Through numerical simulations, we demonstrate that traffic grooming and multipath routing, together, increase spectral efficiency and reduce resource consumption over existing schemes. We show that the proposed scheme offers significant performance improvements in networks with low degrees of connectivity, high traffic loads, and long links

Regenerator Allocation in Nonlinear Elastic Optical Networks With Random Data Rates

We optimize the regenerator allocation in nonlinear elastic networks whose traffic demands have random data rates. Compared with previous regenerator allocation algorithms, our method achieves the same blocking probability with 11% fewer regenerator sites

Joint Assignment of Power, Routing, and Spectrum in Static Flexible-Grid Networks

This paper proposes a novel network planning strategy to jointly allocate physical layer resources together with the routing and spectrum assignment in transparent nonlinear flexible-grid optical networks with static traffic demands. The physical layer resources, such as power spectral density, modulation format, and carrier frequency, are optimized for each connection. By linearizing the Gaussian noise model, both an optimal formulation and a low complexity decomposition heuristic are proposed. Our methods minimize the spectrum usage of networks, while satisfying requirements on the throughput and quality of transmission. Compared with existing schemes that allocate a uniform power spectral density to all connections, our proposed methods relax this constraint and, thus, utilize network resources more efficiently. Numerical results show that by optimizing the power spectral density per connection, the spectrum usage can be reduced by around 20% over uniform power spectral density schemes

Regenerator Site Predeployment in Nonlinear Dynamic Flexible-Grid Networks

A regenerator predeployment algorithm is proposed in dynamic translucent flexible-grid networks based on the GN model. The randomness of traffic bandwidth requests is exploited to allocate regenerators efficiently. Our method accommodates 30% more demands than benchmark methods

Towards a green optical Internet

Increasing electricity consumption significantly affects all nations from environmental, social, and economic perspectives. Among the contributors to this problem is rising power consumption of the Internet’s backbone network due to expanding Internet traffic volumes. This thesis addresses the power consumption minimization problem of the Internet's backbone network. Existing solutions to reduce power consumption are identified and categorized into four approaches of network redesign, traffic engineering, power-aware networking, and load-adaptive operation. Network redesign solutions either modify core nodes by incorporating advanced devices or optimize the physical link topology. Traffic engineering solutions aggregate multiple traffic flows into fewer streams using wavelength/waveband grooming. Power-aware networking solutions vary the operating states of network devices according to traffic variability. Load-adaptive operation solutions use high-rate network devices with Mixed Line Rates (MLR) to serve traffic. To reduce power consumption of an Optical Circuit Switched (OCS) network, each chapter derives solutions from one or more approaches. First, network redesign and traffic engineering solutions are combined to develop a novel sparse grooming algorithm. The proposed algorithm selectively places core routers to reduce power consumption by 688 kW over a traditional network. Second, network redesign and power-aware networking solutions are integrated to develop two novel strategies that use different algorithms to reduce cost and power consumption of a survivable network. Cost is reduced by 40% and power consumption is reduced by 1.3 MWh in a day. Third, the effect of grouping policy and band size and configuration design parameters on power consumption of a waveband-groomed network is analyzed. Proposed algorithms show that power consumption of this Band Switched Network (BSN) can be reduced in different traffic environments by using specific design parameters. Fourth, traffic engineering and load-adaptive operation solutions are combined to develop three new schemes and two algorithms that assign line rates and wavelengths/wavebands in the network, respectively. Power consumption of this MLR-based BSN reduces by 80% and 17% over two Single Line Rate (SLR)-based traditional networks. Lastly, solutions from network redesign and power-aware networking are integrated to develop a novel burst assembly scheme that reduces power consumption of a sleep-mode-enabled Optical Burst Switched (OBS) network by approximately 0.5 kW than when traditional schemes are used

Towards a green optical Internet

Increasing electricity consumption significantly affects all nations from environmental, social, and economic perspectives. Among the contributors to this problem is rising power consumption of the Internet’s backbone network due to expanding Internet traffic volumes. This thesis addresses the power consumption minimization problem of the Internet's backbone network. Existing solutions to reduce power consumption are identified and categorized into four approaches of network redesign, traffic engineering, power-aware networking, and load-adaptive operation. Network redesign solutions either modify core nodes by incorporating advanced devices or optimize the physical link topology. Traffic engineering solutions aggregate multiple traffic flows into fewer streams using wavelength/waveband grooming. Power-aware networking solutions vary the operating states of network devices according to traffic variability. Load-adaptive operation solutions use high-rate network devices with Mixed Line Rates (MLR) to serve traffic. To reduce power consumption of an Optical Circuit Switched (OCS) network, each chapter derives solutions from one or more approaches. First, network redesign and traffic engineering solutions are combined to develop a novel sparse grooming algorithm. The proposed algorithm selectively places core routers to reduce power consumption by 688 kW over a traditional network. Second, network redesign and power-aware networking solutions are integrated to develop two novel strategies that use different algorithms to reduce cost and power consumption of a survivable network. Cost is reduced by 40% and power consumption is reduced by 1.3 MWh in a day. Third, the effect of grouping policy and band size and configuration design parameters on power consumption of a waveband-groomed network is analyzed. Proposed algorithms show that power consumption of this Band Switched Network (BSN) can be reduced in different traffic environments by using specific design parameters. Fourth, traffic engineering and load-adaptive operation solutions are combined to develop three new schemes and two algorithms that assign line rates and wavelengths/wavebands in the network, respectively. Power consumption of this MLR-based BSN reduces by 80% and 17% over two Single Line Rate (SLR)-based traditional networks. Lastly, solutions from network redesign and power-aware networking are integrated to develop a novel burst assembly scheme that reduces power consumption of a sleep-mode-enabled Optical Burst Switched (OBS) network by approximately 0.5 kW than when traditional schemes are used

Regenerator site selection in impairment-aware elastic optical networks

We propose a novel regenerator site selection scheme for nonlinear impairment-aware elastic optical networks. The proposed scheme reduces bandwidth use by up to 40% in a realistic network by employing only 6 regenerator sites

Nonlinear-Impairments- and Crosstalk-Aware Resource Allocation Schemes for Multicore-Fiber-based Flexgrid Networks

Abstract: In this study, we propose a novel spectrum and core allocation scheme that incorporates both intra-core physical layer impairments and inter-core crosstalk. We demonstrate that accounting for the latter increases spectral efficiency by at least 50% when crosstalk is significant

Nonlinear-Impairments- and Crosstalk-Aware Resource Allocation Schemes for Multicore-Fiber-based Flexgrid Networks

Abstract: In this study, we propose a novel spectrum and core allocation scheme that incorporates both intra-core physical layer impairments and inter-core crosstalk. We demonstrate that accounting for the latter increases spectral efficiency by at least 50% when crosstalk is significant