National Science Foundation Network Research Articles

Using Convolutional Neural Networks for Blocking Prediction in Elastic Optical Networks

This paper presents a study on connection-blocking prediction in Elastic Optical Networks (EONs) using Convolutional Neural Networks (CNNs). In EONs, connections are established and torn down dynamically to fulfill the instantaneous requirements of the users. The dynamic allocation of the connections may cause spectrum fragmentation and lead to network performance degradation as connection blocking increases. Predicting potential blocking situations can be helpful during EON operations. For example, this prediction could be used in real networks to trigger proper spectrum defragmentation mechanisms at suitable moments, thereby enhancing network performance. Extensive simulations over the well-known NSFNET (National Science Foundation Network) backbone network topology were run by generating realistic traffic patterns. The obtained results are later used to train the developed machine learning models, which allow the prediction of connection-blocking events. Resource use was continuously monitored and recorded during the process. Two different Convolutional Neural Network models, a 1D CNN (One-Dimensional Convolutional Neural Network) and 2D CNN (Two-Dimensional Convolutional Neural Network), are proposed as the predicting methods, and their behavior is compared to other conventional models based on an SVM (Support Vector Machine) and KNN (K Nearest Neighbors). The results obtained show that the proposed 2D CNN predicts blocking with the best accuracy (92.17%), followed by the SVM, the proposed 1D CNN, and KNN. Results suggest that 2D CNN can be helpful in blocking prediction and might contribute to increasing the efficiency of future EON networks.

Deep reinforcement learning‐based routing and resource assignment in quantum key distribution‐secured optical networks

AbstractIn quantum key distribution‐secured optical networks (QKD‐ONs), constrained network resources limit the success probability of QKD lightpath requests (QLRs). Thus, the selection of an appropriate route and the efficient utilisation of network resources for establishment of QLRs are the essential and challenging problems. This work addresses the routing and resource assignment (RRA) problem in the quantum signal channel of QKD‐ONs. The RRA problem of QKD‐ONs is a complex decision making problem, where appropriate solutions depend on understanding the networking environment. Motivated by the recent advances in deep reinforcement learning (DRL) for complex problems and also because of its capability to learn directly from experiences, DRL is exploited to solve the RRA problem and a DRL‐based RRA scheme is proposed. The proposed scheme learns the optimal policy to select an appropriate route and assigns suitable network resources for establishment of QLRs by using deep neural networks. The performance of the proposed scheme is compared with the deep‐Q network (DQN) method and two baseline schemes, namely, first‐fit (FF) and random‐fit (RF) for two different networks, namely The National Science Foundation Network (NSFNET) and UBN24. Simulation results indicate that the proposed scheme reduces blocking by 7.19%, 10.11%, and 33.50% for NSFNET and 2.47%, 3.20%, and 19.60% for UBN24 and improves resource utilisation up to 3.40%, 4.33%, and 7.18% for NSFNET and 1.34%, 1.96%, and 6.44% for UBN24 as compared with DQN, FF, and RF, respectively.

Communication costs in science: evidence from the National Science Foundation Network

Abstract How do communication costs affect the creation of scientific output? This study examines changes in scientific output and citation patterns following an institution’s connection to the National Science Foundation Network (NSFNET), an early version of the Internet. Established in 1985 to connect five NSF-sponsored supercomputers, the NSFNET national internet backbone quickly expanded to universities across the United States by linking existing and newly formed, wide-area regional computer networks. I estimate the effect of connection to the national internet backbone on citations per paper by exploiting plausibly exogenous variation in the connection times of the regional NSFNET networks. Following connection to the national NSFNET, average citations per paper increase by over 10% relative to the pre-connection mean. Subgroup analyses reveal that the net effect was driven largely by middle- and top-tier institutions. Finally, I show that NSFNET connection led to a decline in interdisciplinary citations and an increase in within-field citations.

Improved spectral allocation in optical wireless communication based on quadrature amplitude modulation using metaheuristic wavelength division multiplexing

With the current surge in interest in high-speed wireless access to wireless communication data networks, appealing, and OFDM (Orthogonal frequency-division multiplexing) for achieving high data speeds. This research ends the real-time exception by proposing a larger number of subcarriers at 35 km/h data rates based on wireless communication as well as spectrum assignment approach is proposed. Simultaneous transmission has also been achieved using OFDM-QAM (Quadrature Amplitude Modulation). As a direct result of comparing, it to the signal delivered, a bit-error-rate performance calculation comparison has been done. The experimental analysis has been carried out for National Science Foundation Network (NSFNET) and EON (European Optical Network)− 28 network topology in terms of SNR, energy efficiency, Throughput and spectral efficiency. For National Science Foundation Network (NSFNet) topology the obtained SNR of 72 %, energy efficiency of 95 %, throughput of 96 % and spectral efficiency of 92 % and EON-28 topology of the network, the proposed technique obtained 70 % SNR, 92 % energy efficiency, 97 % throughput and 95 % spectral efficiency.

Simulation approaches for multi-state network reliability estimation: Practical applications

In this study, simulation approaches for the reliability estimation of a multi-state network (MSN) are developed; the approaches obviate the reliance on known capacity probability distributions. Two procedures are proposed to randomly generate the system (capacity) state, which is further compared with the lower bounds of demand, for estimating system reliability. In particular, the simulation approaches consider the time-varying reliability function for components in the MSN. Two examples, i.e., with and without considering time-varying reliability functions, are investigated to determine the effectiveness (accuracy, convergence, and variance) and efficiency of the proposed procedures. Additionally, a practical case of the National Science Foundation Network is investigated to validate the scalability and applicability of the proposed procedures. Experimental results show that both proposed procedures are effective and efficient for estimating the system reliability of an MSN.

NHERI@UC San Diego 6-DOF Large High-Performance Outdoor Shake Table Facility

Since its commissioning in 2004, the UC San Diego Large High-Performance Outdoor Shake Table (LHPOST) has enabled the seismic testing of large structural, geostructural and soil-foundation-structural systems, with its ability to accurately reproduce far- and near-field ground motions. Thirty-four (34) landmark projects were conducted on the LHPOST as a national shared-use equipment facility part of the National Science Foundation (NSF) Network for Earthquake Engineering Simulation (NEES) and currently Natural Hazards Engineering Research Infrastructure (NHERI) programs, and an ISO/IEC Standard 17025:2005 accredited facility. The tallest structures ever tested on a shake table were conducted on the LHPOST, free from height restrictions. Experiments using the LHPOST generate essential knowledge that has greatly advanced seismic design practice and response predictive capabilities for structural, geostructural, and non-structural systems, leading to improved earthquake safety in the community overall. Indeed, the ability to test full-size structures has made it possible to physically validate the seismic performance of various systems that previously could only be studied at reduced scale or with computer models. However, the LHPOST's limitation of 1-DOF (uni-directional) input motion prevented the investigation of important aspects of the seismic response of 3-D structural systems. The LHPOST was originally conceived as a six degrees-of-freedom (6-DOF) shake table but built as a single degree-of-freedom (1-DOF) system due to budget limitations. The LHPOST is currently being upgraded to 6-DOF capabilities. The 6-DOF upgraded LHPOST (LHPOST6) will create a unique, large-scale, high-performance, experimental research facility that will enable research for the advancement of the science, technology, and practice in earthquake engineering. Testing of infrastructure at large scale under realistic multi-DOF seismic excitation is essential to fully understand the seismic response behavior of civil infrastructure systems. The upgraded 6-DOF capabilities will enable the development, calibration, and validation of predictive high-fidelity mathematical/computational models, and verifying effective methods for earthquake disaster mitigation and prevention. Research conducted using the LHPOST6 will improve design codes and construction standards and develop accurate decision-making tools necessary to build and maintain sustainable and disaster-resilient communities. Moreover, it will support the advancement of new and innovative materials, manufacturing methods, detailing, earthquake protective systems, seismic retrofit methods, and construction methods. This paper will provide a brief overview of the 1-DOF LHPOST and the impact of some past landmark projects. It will also describe the upgrade to 6-DOF and the new seismic research and testing that the LHPOST6 facility will enable.

Quality of transmission-aware control plane performance analysis for elastic optical networks

Physical layer impairment-aware control plane techniques are studied for dynamic networking of elastic optical networks (EONs). To this end, performance of three control plane architectures, the generalized multi-protocol label switching (GMPLS), the GMPLS method with a path computation element unit, and the software-defined networking (SDN), are analyzed considering nonlinear interference (NLI) noise (consisting of self-phase and cross-phase modulation effects) and amplified spontaneous emission noise. Signal-to-noise ratio estimation of all the control plane architectures is performed by means of the well established gaussian noise model. To reduce the blocking probability caused by the NLI noise in EONs, an impairment-aware routing and spectrum assignment algorithm is proposed to ensure a required quality of transmission for requested light-paths. Moreover, transmit launch power influence on blocking probability is investigated exploiting extensive numerical simulations based on stochastic traffic modeling for the investigated control plane architectures in Pan-European and national science foundation network (NSFNET) topologies. The numerical results show nearly 50% improvement in blocking probability of the SDN control plane by applying an impairment aware scheme at traffics around 200 Erlang. Furthermore, the results indicate that the lowest blocking probability is observed at a transmit power of 0 dBm for all the control plane techniques.

Novel approach to jointly optimize working and spare capacity of survivable optical networks

Abstract As technology advancing day by day, the data rate of optical network is moving towards Tb/s speed. The minimum capacity utilization and survivability are the crucial requirement in such high speed optical networks. This research work presents a new approach to calculate both working and spare capacity with the help of single mathematical programming model named as joint capacity planning model. The working traffic and restored traffic are routed jointly in proposed joint capacity planning model. Therefore the joint capacity planning model required minimum capacity in as compare to other optimization models. To evaluate our model, three example networks are proposed i.e., network A (6 node), network B (8 node) & National science foundation network (14 node). Results of these networks are analyzed and compared. The capacity utilization is optimized by increasing the backup paths of the optical networks. It has also been proved in this manuscript that capacity requirement is dependent on the backup path. The proposed joint capacity model provides fast restoration speed and guaranteed protection for optical network.

Dynamic routing and wavelength assignment for efficient traffic grooming

Abstract The routing and wavelength assignment (RWA) schemes play an important role in all computer networks. The performance of a computer network and resource utilization largely depend on the RWA. The demand for higher bandwidth is increasing with each passing day, so more efficient RWA schemes need to be devolved to cater the increasing requirements. RWA becomes more challenging for dynamic traffic as the nature and flow of data are not known in advance. In this paper, a dynamic RWA scheme has been proposed for establishing a path in optical networks. The proposed scheme is based upon dynamic conversion sensing algorithm. It can be applied on a number of different network topologies. The proposed scheme is dynamic in nature, which is significantly useful for dynamic traffic grooming. The proposed scheme has been applied on 14 nodes National Science Foundation Network (NFSNet). Simulation results have shown that the blocking probability of this scheme is very low as compared to the existing schemes. So, the proposed dynamic RWA scheme enhances the network efficiency. It is useful for congestion hit networks. The reduced blocking probability in wavelength division multiplexing optical networks leads to better resource utilization and enhanced performance.

Communication Costs in Science: Evidence from the National Science Foundation Network

How do communication costs affect the creation of scientific output? This study examines changes in scientific output and citation patterns following an institution's connection to the National Science Foundation Network (NSFnet), an early version of the Internet. Established in 1985 to connect five NSF-sponsored supercomputers, the NSFnet national internet backbone quickly expanded to universities across the United States by linking existing and newly-formed, wide-area regional computer networks. I estimate the effect of connection to the national internet backbone on citations per paper by exploiting plausibly exogenous variation in the connection times of the regional NSFnet networks. Following connection to the national NSFnet, average citations per paper increase by over ten percent relative to the pre-connection mean. Subgroup analyses reveal that the net effect was driven largely by middle- and top-tier institutions. Finally, I show that NSFnet connection led to a decline in interdisciplinary citations and an increase in within-field citations, but I find no evidence of increases in collaboration patterns.

Incremental dynamic analysis and FEMA P695 seismic performance evaluation of a cold‐formed steel–framed building with gravity framing and architectural sheathing

SummaryThe objective of this paper is to present incremental dynamic analysis (IDA) and seismic performance evaluation results for a two‐story cold‐formed steel (CFS)–framed building. The archetype building was designed to current U.S. standards and then subjected to full‐scale shake table tests under the U.S. National Science Foundation Network for Earthquake Engineering Simulation (NEES) program. Test results showed that the building's stiffness and capacity were considerably higher than expected and the building suffered only nonstructural damage even at excitations in excess of Maximum Considered Earthquake levels for a high seismic zone. For the archetype building, three‐dimensional finite element models at different modeling fidelity levels were created using OpenSees. The models are subjected to IDA using the far‐field ground motion records prescribed in Federal Emergency Management Agency (FEMA) P695. Seismic performance quantification following the FEMA P695 procedure shows that if the modeling fidelity only follows the state‐of‐the‐practice, ie, only includes shear walls, unsafe collapse margin ratios are predicted. State‐of‐the‐art models that account for participation from CFS gravity walls and architectural sheathing have overall performance that are consistent with testing, and IDA results indicate acceptable collapse margin ratios, predicated primarily on large system overstrength. Neglecting the lateral force resistance of the gravity system and nonstructural components, as done in current design, renders a safe design in the studied archetype, but largely divorced from actual system behavior. The modeling protocols established here provide a means to analyze a future suite of CFS‐framed archetype buildings for developing further insight on the seismic response modification coefficients for CFS‐framed buildings.

A Spectrum Assignment Algorithm in Elastic Optical Network With Minimum Sum of Weighted Resource Reductions in all Associated Paths

Elastic optical network (EON) is a promising technology for the next generation of optical transport network. Routing, modulation and spectrum assignment is one of the key issues in EON. In the problem, the constraints of spectrum continuity and contiguity must be satisfied. In this paper, we propose a spectrum assignment policy named minimizing sum of weighted resource reductions ( $\boldsymbol {\min \Sigma w\Delta R}$ ) algorithm. The algorithm includes three contributions: 1) The concept of resource reduction ( $\boldsymbol {\Delta R}$ ) is defined to measure variation of idle resources in a path when a spectrum block is assigned to a connection request, which is combination of changes of continuity and contiguity in the path. 2) When a spectrum block in a path is used, resource reductions in all associated paths rather than only the current path are taken into account. 3) A function of path's hop is used as a weight to adjust the path's impact. Simulations were carried out based on the national science foundation network (NSF-Net) and the pan-European Cost239 network (Cost239) to investigate the performance of the algorithm, by comparing with three well-performed benchmarks. Simulation results show that, when the parameters of the metric are set to appropriate values, the proposed algorithm can significantly decrease blocking probability in both two topologies.

Load-Aware Nonlinearity Estimation for Elastic Optical Network Resource Optimization and Management

Elastic optical networks (EONs) have emerged as a promising technology to accommodate the high-capacity and dynamic bandwidth demands of next-generation wireless networks. However, similar to the traditional wavelength division multiplexing optical networks, there exist significant challenges to manage nonlinearity effects in EONs. In this paper, we first analyze state-of-the-art nonlinearity estimation solutions and propose a novel load-aware nonlinearity estimation method. We further present a resource allocation algorithm using the proposed nonlinearity estimation scheme. In case the new embedded lightpath brings additional nonlinearity blocking the existing requests, we propose a mixed integer linear programming model and two heuristic algorithms using the proposed nonlinearity model as the service reconfiguration scheme for efficient resource allocation in EONs. The objective of the solution is to minimize the spectrum resource usage while satisfying the bandwidth demands of the connection and ensuring the quality of transmission. The proposed solutions are evaluated using an extensive simulation with off-line traffic requests and incrementally loaded requests against the benchmark solutions for two types of traffic profiles in a small network with six nodes and nine links and the National Science Foundation network. The results presented in this paper validate the benefits of the proposed nonlinearity estimation model and the corresponding algorithms to minimize the number of allocated frequency slots and service request blocking ratio while improving the overall network capacity.

DHbLP: A Novel Technique for Survivability in Optical Networks

Abstract Dense Wavelength-Division Multiplexing (DWDM) optical networks meet ever-increasing bandwidth demand of internet applications. Network failure results in massive information loss particularly in networks carrying a huge volume of data. Survivability techniques ensure uninterrupted network functioning even in case of failure. Research in the domain of DWDM network survivability has contributed toward the development of protection and restoration techniques to provide resilience in optical networks. In this paper, basic concept of protection and restoration in optical networks has been introduced followed by review and analysis of existing routing and survivability techniques. It is observed that a trade-off among network performance parameters exists for any survivability scheme. A novel scheme, Dynamic Hybrid Technique based on Failure Location and Traffic Priority (DHbLP) adaptable to Quality of Service (QoS) demands, has been proposed. DHbLP is tested for one of the possible failure scenarios in the standard National Science Foundation NETwork (NSFNET) and it is observed that this technique improves network performance in terms of throughput and blocking probability.

Limitation of Erlang B Traffic Model in Elastic Optical Network for Blocking Probability Estimation

Abstract In this paper, an algorithm for multipath connection provisioning in elastic optical network (EON) has been proposed. Initially, the algorithm prefers the single-path routing for service provisioning. But when single-path routing is not adequate to serve a dynamic connection, the algorithm switches to the connection request fragmentation. Its computation is based on the parameters such as capacity_constant and capacity_allowed to fragment the connection request on disjoint paths. Simulation results clearly state that the proposed algorithm performs well in service provisioning as compared to the traditional single-path routing algorithms and improves the average network throughput. Thereafter, we have investigated the limitation of Erlang B traffic model in EON for calculation of link blocking probability using routing and spectrum assignment (RSA) algorithm. It is verified by the following two ways: (i) effect on the blocking probability in case of constant load and (ii) effect of slot width on the blocking probability. Our simulation results indicate that in EON due to dynamic RSA, blocking probability is not constant in case of proportionate varying of call arrival and service rate giving constant load and blocking probability depends on the number of slots per link, but in Erlang B traffic model blocking probability is always constant in case of constant load and it considers wavelength per link instead of slots per link. This is attributed to the fact that Erlang B traffic model fails to calculate blocking probability accurately in EON. We have computed the carried traffic on 14 nodes, 21-link National Science Foundation Network (NSFNET) topology.

Live Migration for Multiple Correlated Virtual Machines in Cloud-Based Data Centers

With the development of cloud computing, virtual machine migration is emerging as a promising technique to save energy, enhance resource utilizations, and guarantee Quality of Service (QoS) in cloud datacenters. Most of existing studies on the virtual machine migration, however are based on a single virtual machine migration. Although there are some researches on multiple virtual machines migration, the author usually does not consider the correlation among these virtual machines. In practice, in order to save energy and maintain system performance, cloud providers usually need to migrate multiple correlated virtual machines or migrate the entire virtual datacenter (VDC) request. In this paper, we focus on the efficient online live migration of multiple correlated VMs in VDC requests, for optimizing the migration performance. To solve this problem, we propose an efficient VDC migration algorithm (VDC-M). We use the US-wide US National Science Foundation (NSF) network as substrate network to conduct extensive simulation experiments. Simulation results show that the performance of the proposed algorithm is promising in terms of the total VDC remapping cost, the blocking ratio, the average migration time and the average downtime.

Large scale centrifuge test of a geomembrane-lined landfill subject to waste settlement and seismic loading

A large scale centrifuge test of a geomembrane-lined landfill subject to waste settlement and seismic loading was conducted to help validate a numerical model for performance based design of geomembrane liner systems. The test was conducted using the 240g-ton centrifuge at the University of California at Davis under the U.S. National Science Foundation Network for Earthquake Engineering Simulation Research (NEESR) program. A 0.05mm thin film membrane was used to model the liner. The waste was modeled using a peat-sand mixture. The side slope membrane was underlain by lubricated low density polyethylene to maximize the difference between the interface shear strength on the top and bottom of the geomembrane and the induced tension in it. Instrumentation included thin film strain gages to monitor geomembrane strains and accelerometers to monitor seismic excitation. The model was subjected to an input design motion intended to simulate strong ground motion from the 1994 Hyogo-ken Nanbu earthquake. Results indicate that downdrag waste settlement and seismic loading together, and possibly each phenomenon individually, can induce potentially damaging tensile strains in geomembrane liners. The data collected from this test is publically available and can be used to validate numerical models for the performance of geomembrane liner systems.

Development of a Risk Framework for Forecasting Earthquake Losses in Port Systems

Ports play a critical role in transportation infrastructure but are vulnerable to seismic hazards. Downtime and reduced throughput from seismic damage in ports results in significant business interruption losses for port stakeholders. Managing risks from systemwide disruptions resulting from earthquake damage has been studied as a central element of a project sponsored by the National Science Foundation Network for Earthquake Engineering Simulation (NEES) program. Presented are the concepts and methods developed for the seismic risk management of a portwide system of berths. The framework used to calculate port losses is discussed, particularly the use of spatially correlated ground motion intensity measures that estimate damage to pile-supported wharves and container cranes, the repair costs and downtimes subsequently determined via repair models for both types of structures, and the impact on cargo handling operations calculated via logistical models of the port system. Results, expressed in the form of loss exceedance curves, are calculated.

Securing the Network Time Protocol

In the late 1970s David L. Mills began working on the problem of synchronizing time on networked computers, and NTP (Network Time Protocol) version 1 made its debut in 1980. This was at a time when the net was a much friendlier place - the ARPANET days. NTP version 2 appeared approximately a year later, about the same time as CSNET (Computer Science Network). NSFNET (National Science Foundation Network) launched in 1986. NTP version 3 showed up in 1993.

Virtual Optical Network Resource Allocation Using PCE Global Concurrent Optimization for Dynamic Deployment of Virtual GMPLS-Controlled WSON

We present dynamic virtual optical network resource allocation (VON RA) algorithms for on-demand deployment of virtual wavelength switched optical networks (WSONs), which is handled by a resource broker with a virtual network topology manager (VNTM). The resource broker with VNTM dynamically configures and deploys independent instances of virtual WSONs over the same physical optical infrastructure and their own independent virtual generalized multiprotocol label switching control plane. The VON RA is computed by a path computation element using global concurrent optimization, which assigns the resources for the virtual optical links (e.g., wavelengths) and nodes. The experimental assessment and performance evaluation have been carried out in the ADRENALINE testbed. We discuss the obtained results on a National Science Foundation Network topology in terms of the VON request blocking rate and VON setup delay, which are used to compare the different proposed algorithms.