Backup Network Research Articles

99.6% efficiency DC-DC coupling for green hydrogen production using PEM electrolyzer, photovoltaic generation and battery storage operating in an off-grid area

This paper presents a novel connection and control strategy for a hydrogen generation system using a proton exchange membrane electrolyzer powered by solar energy in an off-grid area without network backup. Given that, the proposed architecture is based on the indirect control of the Photovoltaic plant (achieved by removing a power-converter), the presented solution is more efficient and more reliable than the traditional scheme. Furthermore, with this innovation one can reach the same hydrogen production with smaller electrolyzers.The methodology includes detailed models of the photovoltaic panel and the electrolyzer, along with a control strategy that considers the degradation mechanisms of the electrolyzer to ensure reliable and prolonged operation. The results show that the proposed strategy keeps the operating power of the electrolyzer constant, even under variations in irradiance, thanks to energy storage in batteries. It is demonstrated that the proposed system offers efficiency above 99.6% during the analyzed period, with a 100% utilization rate of the electrolyzer, avoiding periods of inactivity and high current peaks. The study also includes simulations and experimental tests that confirm the feasibility and effectiveness of the presented solution, highlighting its advantages in terms of efficiency and investment costs compared to direct connections and other existing methods.

Моделирование особенностей работы дистанционной защиты резервных трансформаторов собственных нужд энергоблоков атомной станции при самозапуске мощных двигательных нагрузок

In the article, using computer modeling, an analysis of the operation of distance protection of backup transformers is carried out, providing alternative power supply for the own needs of a nuclear power plant through a backup busbar when disconnected from the power system. During the transition from the main network to the backup network, there is a short period of power off to the sections. At the same time, the powerful motor loads of the sections that have received power begin to operate in the freewheel braking mode. Then the reserve is automatically switched on, which can occur at a more or less favorable moment. At an unfavorable moment, self-starting may be electrically more severe than a short circuit on the busbar. When combining a new network from a backup auxiliary transformer and an autonomous circuit of running machines, transient processes of electromagnetic interaction between machines switching to generator mode and the new network arise. There are some optimal favorable moments for merging networks when it is advisable to carry out self-starting. Due to the complexity of the mathematical description with a high order system of equations and a large number of interaction objects, it is advisable to study these processes using computer modeling. A practical question, which is answered by the calculations and computer modeling, concerns the value of the distance protection setting for the backup transformer for auxiliary needs. Using the developed structural simulation model in MatLab, a series of experiments was carried out on the run-down and self-starting of auxiliary sections with their given composition and load. The range of self-start time corresponded to the operation of automatic switching on of the reserve sections by distance protection. Calculations and modeling show that the adopted setting can be adjusted, ensuring protection of a larger length of the busbar with possible options for connecting auxiliary sections to it. The model is supplemented with an add-on in the form of an external program for detailed processing and visualization of data obtained from oscilloscopes of the MatLab structural model.

Flexible resource optimal allocation strategy for distribution system resilience improvement under failure uncertainty

Extreme disasters have led to huge economical losses to the power system and posed a huge threat to the stable supply of electric energy. Especially for traditional passive distribution network systems, failures of transmission lines, towers, and other equipment will cause large-scale power outages and huge economic losses. In order to improve the ability of the power system to deal with extreme weather disasters, this paper proposes an optimal configuration strategy for the distribution network backup power resource oriented to resilience improvement, considering the uncertainty of equipment failure caused by disasters in the case of a known disaster range. The location and capacity of backup resources can be properly configured to reduce the load shedding of the power distribution network during the disaster process, thereby improving the resilience of the distribution network. The method proposed in this paper is modeled as a two-stage stochastic programming, which includes mix-integer constraints. In the first stage, the optimization problem confirms the capacity and location of the flexible resources. In the second stage, the operational constraints and costs of load shedding are considered. The resilience enhancement method is verified on the improved IEEE-33 node system, and the result shows that the method proposed in this paper can effectively enhance the resilience of the urban power network.

Inter-Core Crosstalk-Aware Backup Network Design Model against Probabilistic Link Failures in Multi-Core Fiber Optical Path Network

Multi-core fiber (MCF) is one of the promising space-division multiplexing technologies to increase the capacity of optical networks. MCF-based networks have two challenges. One is the inter-core crosstalk (XT) that degrades the quality of optical signals in two neighboring fiber cores. The other is network protection against link failures that cause massive data loss. One way to protect against multiple link failures is to prepare physically separated links as a backup network. Probabilistic protection improves the efficiency of protection by allowing a certain probability of protection failure. Existing studies on backup network design with probabilistic protection do not target MCF-based networks, which raises problems such as protection failure due to the inter-core XT and excessive consumption of optical resources. To address these problems, this paper proposes a XT-aware backup network design model for the MCF optical path networks. The proposed model protects the network against probabilistic multiple link failures. We adopt probabilistic protection that allows a certain probability of protection failure due to the inter-core XT and minimizes the required number of links in the backup network. We present an algorithm to satisfy the probabilistic protection requirement and formulate the model as an integer linear programming problem. We develop a heuristic approach to apply the proposed model to larger networks. Numerical results observe that the proposed model requires fewer links than the dedicated allocation model, which provisions the backup paths in the same manner as the primary paths.

Rapid Reinstatement of Cancer Care after Hurricane Ian

Category 4 Hurricane Ian brought significant destruction and challenges to western Florida's healthcare facilities. A Radiation Oncology practice network serving the area minimized interruptions in care by implementing planned and improvised solutions. Examining actions that allowed rapid recovery of care could assist others in disaster response. The National Hurricane Center issued a hurricane warning 36 hours prior to Ian's landfall. Center closures were based on evacuations and scheduled take down of the power grid. Computers were unplugged, elevated and wrapped in plastic. The LINAC was isolated from the power grid at the main breaker. Staff and patient contacts were printed. Communication techniques were agreed upon for post-storm scenarios with or without cellular service and internet. Hurricane Ian made landfall on September 28 with 150 mph sustained winds and gusts of 216 mph. Unsafe conditions prevented action on September 28. Facility assessment began on September 29. The majority of facilities were inaccessible due to impassible roads and entry hazards, or could not be safely occupied. Based on location and condition, one center from the network of facilities was selected for immediate operational restoration. After confirmation that the site's restored power would remain stable, the LINAC was powered on. An onsite engineering evaluation was done to assess machine functionality and vacuum integrity. Medical Physics then performed monthly QA and isocenter verification due to concern for building vibrations from extreme winds. Interfacing with patient charts in the Aria database was more complex than anticipated. Aria is a hub that uses relative paths to refer to plans, structure sets, images, and radiotherapy treatment records stored in remote servers. These Aria servers could not be accessed because the remote sites had no power. As the Aria servers could not be moved, teams went to retrieve the related Adaptivo servers to allow re-import of patient plans. When booted these servers had no common network and no graphical user interface. Using command line tools, the servers were added to the hub network and IP addresses were assigned. MS-DOS command Robocopy allowed a large-scale resumable transfer from Adaptivo patient folders to the Eclipse import directory. Plan validation and QA followed. Records could not be updated with delivered treatments, necessitating reconciliation of total dose when normal operations resumed. Within 72 hours of Ian passing, treatment resumed for all patients within the cancer center network who were able to access the restored site. Within days, seven of the eight regional centers were operational and patients were redistributed. The unexpected challenges posed by data and network access suggest that improving data location and back-up networks could facilitate center response and resiliency in future disasters.

Kualitas Pelayanan Jemput Bola bagi Warga Disabilitas di Dinas Kependudukan dan Pencatatan Sipil Kota Cimahi

Cimahi City Government initiated “jemput bola” public service for citizen with disability. “Jemput bola” public service is an act of recording electronic citizen identity card (e-KTP) for citizen with disabilty, elderly, and acute sickness by going directly to the their houses. This study aimed to determine the implementation of population administration services through “jemput bola” public service for citizen with disability at the Population and Civil Registration Office of the Cimahi City along with the obstacles that occured during the process. The research method used was qualitative research. Sources of data in this study were interview, direct observation, and document study. The results of this study indicated that in carrying out ball “jemput bola” public service for citizen with disability, there were some obstacles, i.e.: the absence of Standard Operating Procedures, internet network quality, character of citizen with disability, and access toward citizen’s house location. To overcome the main obstacles, researchers created a Standard Operating Procedure document as guidance for “jemput bola” public service for citizen with disability. For internet network problem, officers could prepare a specific internet network system that was worked in the targeted area and also brought up a backup network. For obstacle related to mood disturbance of citizen with disability, officers needed special training to handle challenging situation so they could serve them in a more appropriate way. For obstacle related to access toward citizen’s house location, officers could bring recording equipment to citizen’s house. This research could benefit Cimahi City Office of Population and Civil Registration to improve the quality of “jemput bola” public service for citizen with disability and also as reference for similar research.

An Autonomous Electric Power System with a Permanent Magnet Synchronous Generator

The article deals with an autonomous electric power system (AEPS) with a permanent magnet synchronous generator (PMSG), storage battery (SB), and a static reversible converter (RC). The autonomous system has a transformer galvanic isolation between the AC and DC voltage networks. The converter operates in two modes: as a rectifier (the generator is in operation) and as an inverter (the generator is out of service). In the rectifier mode, the converter operates as an active voltage rectifier (AVR), which charges (recharges) the storage battery and stabilizes the generator voltage to form the main network. In the inverter mode, the converter operates as an autonomous voltage inverter to form a backup network. The autonomous electric power system structures were analyzed, and its two rational versions with the lowest current load of the converter have been selected based on the analysis results. One version of the structure, which contains, apart from the converter, an additional magnetizing device that stabilizes the generator voltage, operates with a DC network voltage of 250 ± 75 V. The other option does not contain an additional magnetizing device (MD) and operates with a DC network voltage of 600–640 V. For both versions, the automatic control system operating modes with stabilizing the generator voltage and charging the storage battery have been studied by simulating them on a computer.

Topologi Redundansi Link Untuk Keamanan Serta Mitigasi Ketersediaan Jaringan Komputer Menggunakan Rapid Spanning Tree Protocol

The frequent occurrence of natural disasters requires telecommunications companies to require a backup internet backbone line if the telecommunications infrastructure is damaged/disconnected due to natural disasters. Reporting from inet.detik.com APJII revealed that the Jakarta-Singapore fiber optic network had broken, which had an impact on internet services in Indonesia. Fiber optic repair can take up to 2-3 weeks requiring network backup, the main solution for network backup with satellite, but problems will arise when configuration for satellite lines takes 1-2 days. Problems arise again when combined between fiber optic internet lines and satellite internet lines which cause the looping network to create network disturbances, to maintain interference, a spanning tree protocol method is needed to backup lines automatically and create link redundancy if one of the lines is problematic or disconnected. The purpose of this study is to design a link redundancy topology for security and mitigation of network availability using the rapid spanning tree protocol (RSTP) with router rb750gr3, switch rb260gs and switch dgs-108. In the RSTP network topology, it is designed with 3 redundant lines connected between the rb260gs switch and the dgs-108 switch, with an on-stick router rb750gr3 and is designed with 6 access mode vlan lines. In testing the inter-vlan network, RSTP terminates the redundancy link and then uses the ping command at the command prompt to determine how many minutes to backup the link. The NDLC method is used in determining how many seconds to backup this redundancy link using. The results of testing the link termination ether2-switch-mikrotik and ether1-switch-dlink using the "ping" command for 20 seconds in determining how many seconds to backup the link get the result that Request Time Out does not occur and the average time for each pc in determining the backup path for the pc-vlan20 22.9ms, pc-vlan30 35ms, pc-vlan70 23.5ms. The results of link termination testing ether3-switch-mikrotik and ether2-switch-dlink using the "ping" command for 20 seconds in determining how many seconds to backup the link get the result that there is no Request Time Out and the average time for each pc in determining the backup path for the pc-vlan20 23ms, pc-vlan30 24ms, pc-vlan70 43.7ms.

URLLC service-oriented reliable network deployment over MEC enabled TDM-PON based cloud radio access network

New emerging ultra-reliable and low latency communications (URLLC) services have imposed challenged stringent low latency and reliability requirements on fifth generation and beyond (5G/B5G) cloud radio access network (CRAN). However, limited research has been discussed service-oriented reliable network deployment in the mobile edge computing (MEC)-enabled time-division multiplexing-passive optical network (TDM-PON) based CRAN. Moreover, different from most previous protection studies, both optical transport and functional processing resources in multiple domains should be considered in the network deployment of a converged network. To mitigate these limitation, we present a mixed integer linear programming (MILP) for URLLC service-oriented reliable network deployment under the physical and management constraints in MEC-enabled TDM-PON based CRAN. Given the model’s complexity, a heuristic algorithm called “Time-efficient completely isolated protection scheme (TECIPS)” is proposed, which can completely guarantee protection through establishing both primary network topology and strong isolated backup network topology against multiple network failures, while reducing redundant transmission latency and backup recovery latency for URLLC services. Simulation results indicate that our proposed algorithm significantly reduces total latency compared to the benchmark algorithm and receives the near-optimal solution of MILP in both sparse and dense networks with an acceptable time complexity. In addition, the impact of key parameters on the consumption of total transmission latency and backup recovery latency is also evaluated.

Adaptive Protection of Scientific Backbone Networks Using Machine Learning

In this article, we propose a new protection scheme for backbone networks to guarantee high service availability. The presented scheme does not require any reconfiguration immediately after the failure (i.e., it is proactive). At the same time, it does not require any reserved backup network resources either. To achieve these seemingly contradictory goals, we utilize the recent advancements in Machine Learning (ML) to implement a network intelligence that periodically re-allocates the unused capacity as protection bandwidth to meet the service availability requirements of each connection. Our goal is achieved by two components (1) predicting the traffic for the next period on each link, and (2) intelligently selecting the best fit dedicated protection scheme for the next period depending on the estimated unused (spare) bandwidth and the previous service availability violations. Note that re-allocating protection bandwidth affects neither the operational connections nor the current best practice of operators to over-provision network bandwidth to support elephant flows. Finally, we provide a case study on the real traffic from Energy Sciences Network (ESnet), a high-speed, international scientific backbone network. The key benefit of our framework is that adaptively utilizing the over-provisioned bandwidth for spare capacity is sufficient to improve the availability from three-nines to five-nines (in ESnet for the 30 examined connections). The drawback is negligible bandwidth limitations; the user perceives a minor and very temporal bandwidth limitation in less than 0.1% of the time.

Joint link-level and network-level reconfiguration for urban mmWave wireless backhaul networks

Due to the rapid densification of small cells in 5G and beyond cellular networks, deploying wired high-bandwidth connections to every small cell base station (BS) is difficult, particularly in older metropolitan areas where infrastructure for fiber deployment is lacking. For this reason, mmWave wireless backhaul has been proposed as a cost-effective and flexible alternative that has the potential to support the high data rates needed to accommodate backhaul traffic demands. To address the robustness of such networks, we investigate a novel relay-assisted backhaul architecture, where a number of small-cell BSs and relays are deployed, e.g. on the lampposts of urban streets. In this scenario, the interconnected logical links constitute a mesh network, which offers opportunities for both link-level and network-level reconfiguration to overcome blockages and/or node failures. We present two joint link-network level reconfiguration schemes for recovery after exceptional events. One prioritizes relay path (link-level) reconfiguration and uses alternate network-level paths only if necessary. The other splits traffic on both reconfigured logical links and backup network paths to improve throughput. Through simulation, the reconfiguration schemes are shown to not only provide near-optimal backhaul survivability but to also maintain high network throughput across a range of scenarios for urban mmWave backhaul networks. The schemes are also validated to significantly outperform existing purely link-level and purely network-level reconfiguration schemes.

From Mirrors to Free-Space Optical Communication—Historical Aspects in Data Transmission

Fast communication is of high importance. Recently, increased data demand and crowded radio frequency spectrum have become crucial issues. Free-Space Optical Communication (FSOC) has diametrically changed the way people exchange information. As an alternative to wire communication systems, it allows efficient voice, video, and data transmission using a medium like air. Due to its large bandwidth, FSOC can be used in various applications and has therefore become an important part of our everyday life. The main advantages of FSOC are a high speed, cost savings, compact structures, low power, energy efficiency, a maximal transfer capacity, and applicability. The rapid development of the high-speed connection technology allows one to reduce the repair downtime and gives the ability to quickly establish a backup network in an emergency. Unfortunately, FSOC is susceptible to disruption due to atmospheric conditions or direct sunlight. Here, we briefly discuss Free-Space Optical Communication from mirrors and optical telegraphs to modern wireless systems and outline the future development directions of optical communication.

Optimization Model for Backup Network Design with Primary and Backup Routing against Multiple Link Failures under Uncertain Traffic Demands

Optimization Model for Backup Network Design with Primary and Backup Routing against Multiple Link Failures under Uncertain Traffic Demands

Innovative sources of increasing the competitiveness of rural green tourism enterprises

The subject of research is the theoretical and practical aspects of the definition and implementation of innovations, forms and directions of innovation in order to increase the competitiveness of rural green tourism enterprises. The aim of the work is to identify innovative sources of increasing the competitiveness of rural green tourism enterprises and substantiate the factors, components and tools for innovation in a knowledge economy, digital technologies, non-cash payments, high-speed Internet. The methodological basis of the article were the theoretical and methodological provisions of modern business economics, historical and monographic methods of scientific knowledge, as well as system-structural analysis and synthesis of the study of phenomena and processes, problem-based approach in justifying types, forms and directions of innovation. Results of work. The sources and offered components, directions and tools of introduction of innovations in work of the enterprises of rural green tourism, including in the form of organizational and administrative, marketing, product groups of them are revealed; in the form of IT startups, touring and digital systems and backup networks; timesharing, clustering, strategic alliances and clubs; smart Internet projects, software organization and management of the actual agro-villages and tourist enterprises in the countryside to increase their competitiveness. Field of application of results. Conclusions and results can be used in the work of rural green tourism enterprises, rural communities, public organizations, local governments; in the educational and scientific process of economic faculties of universities, colleges of tourist specialization, other institutions of higher education. Conclusions. Innovative activity in the system of strategic goals, priorities and guidelines for increasing the competitiveness of rural green tourism enterprises in the era of knowledge economy and digitalization will take a leading place. The realization of their important socio-economic functions, as well as other subjects of social life is becoming increasingly associated with an innovative type of development. In turn, it is based on a continuous and purposeful process of finding, preparing and implementing innovations. The possibility and motivation to obtain higher incomes and the need to increase the efficiency of financial and investment resources forces the participants of the tourism business in the countryside to purposefully create new tastes, interests and needs, introduce fundamentally new products, products, services and technologies. All this is also connected with the acceleration of innovation processes.

Optimization Approach to Minimize Backup Capacity Considering Routing in Primary and Backup Networks for Random Multiple Link Failures

Optimization Approach to Minimize Backup Capacity Considering Routing in Primary and Backup Networks for Random Multiple Link Failures

Finding Minimum-Weight Link-Disjoint Paths with a Few Common Nodes

Network survivability has drawn certain interest in network optimization. However, the demand for full protection of a network is usually too restrictive. To overcome the limitation of geographical environments and to save network resources, we turn to establish backup networks allowing a few common nodes. It comes out the problem of finding k link-disjoint paths between a given pair of source and sink in a network such that the number of common nodes shared by at least two paths is bounded by a constant and the total link weight of all paths is minimized under the above constraints. For the case k = 2, where we have only one backup path, several fast algorithms have been developed in the literature. For the case k > 2, little results are known. In this paper, we first establish the NP-hardness of the problem with general k. Motivated by the situation that each node in a network may have a capability of multicasting, we also study a restricted version with one more requirement that each node can be shared by at most two paths. For the restricted version, we build an ILP model and design a fast algorithm by using the techniques of augmenting paths and splitting nodes. Furthermore, experimental results on synthetic and real networks show that our algorithm is effective in practice.

An adaptive ensemble classification framework for real-time data streams by distributed control systems

Smart Grids are critical infrastructure networks. They play a critical role in the survival of our postmodern economies, as all other areas depend on their availability. An interruption in their operation may have a direct impact on the availability of other services (e.g., health, transportation). The problem is particularly intense when no backup networks are available, or the required recovery time is beyond backup autonomy. The transition to a decentralized management and control system for these networks requires digital technologies, advanced interconnected system communications, and Internet access. These technologies expose critical infrastructure networks to external threats that require careful assessment of cyber-security risks and appropriate countermeasures. An important factor that enhances the range of threats is the heterogeneity of Smart Grids, which incorporate industrial control systems such as the SCADA, distributed control system, and programmable logic controllers to which security improvements may not have been made since they were installed. Υet, another serious problem arises from the fact that older technologies were designed at times when cyber-security was not part of their technical design specifications. At the same time, it should be seriously considered that many of the systems of these networks that can be cyber-attacked may not be easily disconnected, as this could potentially lead to generalized operational problems. In this scientific research, a sophisticated active security framework is proposed, which is based solely on advanced computational intelligence methods and concerns the digital security of critical infrastructure networks. Specifically, this research introduces a sophisticated adaptive ensemble classification framework for real-time data streams by distributed control systems. It is a “Kappa” architecture framework that is based on a two-step online ensemble learning model based on bagging and boosting methods. The aim is performance of real-time analysis and evaluation of data flows from Smart Grids, toward the effective identification of APT attacks.

Involving End Users in Adapting a Spanish Version of a Web-Based Mental Health Clinic for Young People in Colombia: Exploratory Study Using Participatory Design Methodologies.

BackgroundHealth information technologies (HITs) hold enormous promise for improving access to and providing better quality of mental health care. However, despite the spread of such technologies in high-income countries, these technologies have not yet been commonly adopted in low- and middle-income countries. People living in these parts of the world are at risk of experiencing physical, technological, and social health inequalities. A possible solution is to utilize the currently available HITs developed in other counties.ObjectiveUsing participatory design methodologies with Colombian end users (young people, their supportive others, and health professionals), this study aimed to conduct co-design workshops to culturally adapt a Web-based Mental Health eClinic (MHeC) for young people, perform one-on-one user-testing sessions to evaluate an alpha prototype of a Spanish version of the MHeC and adapt it to the Colombian context, and inform the development of a skeletal framework and alpha prototype for a Colombian version of the MHeC (MHeC-C).MethodsThis study involved the utilization of a research and development (R&D) cycle including 4 iterative phases: co-design workshops; knowledge translation; tailoring to language, culture, and place (or context); and one-on-one user-testing sessions.ResultsA total of 2 co-design workshops were held with 18 users—young people (n=7) and health professionals (n=11). Moreover, 10 users participated in one-on-one user-testing sessions—young people (n=5), supportive others (n=2), and health professionals (n=3). A total of 204 source documents were collected and 605 annotations were coded. A thematic analysis resulted in 6 themes (ie, opinions about the MHeC-C, Colombian context, functionality, content, user interface, and technology platforms). Participants liked the idea of having an MHeC designed and adapted for Colombian young people, and its 5 key elements were acceptable in this context (home page and triage system, self-report assessment, dashboard of results, booking and video-visit system, and personalized well-being plan). However, to be relevant in Colombia, participants stressed the need to develop additional functionality (eg, phone network backup; chat; geolocation; and integration with electronic medical records, apps, or electronic tools) as well as an adaptation of the self-report assessment. Importantly, the latter not only included language but also culture and context.ConclusionsThe application of an R&D cycle that also included processes for adaptation to Colombia (language, culture, and context) resulted in the development of an evidence-based, language-appropriate, culturally sensitive, and context-adapted HIT that is relevant, applicable, engaging, and usable in both the short and long term. The resultant R&D cycle allowed for the adaptation of an already available HIT (ie, MHeC) to the MHeC-C—a low-cost and scalable technology solution for low- and middle-income countries like Colombia, which has the potential to provide young people with accessible, available, affordable, and integrated mental health care at the right time.

A Well Organized Model in Cloud Computing Platform for Data Accessing

Cloud Computing is a trending technology. The main benefit is user will pay only for the resources which have been utilized in the cloud services. Data which are stored in cloud can be accessed by the people from anywhere in the world using internet connection. Because of difficulties in data access and lack of security, in the current database system people are moving to Cloud Service Provider (CSP). Network backup and recovery method are used in CSP so there is no data loss in case of hardware failure. In this paper, we planned an efficient model in cloud computing for data accessing which will reduce the search time of providing the public key of the data owner. Not only data storage and security, data access also plays an important role to consume less time. So, in this proposed system we are going to increase the time efficiency for the data accessing.

Backup Network Design Against Multiple Link Failures to Avoid Link Capacity Overestimation

This paper proposes a backup network design scheme that can determine backup link capacity in practical time. The proposed scheme suppresses the required backup link capacity while providing a guaranteed level of recovery against multiple independent link failures. The conventional scheme is based on robust optimization and suffers from the problem of overestimating the backup link capacity. The proposed scheme addresses the overestimation problem by computing the probabilistic distribution function of required backup link capacity in polynomial time. We formulate the backup network design problem with the proposed scheme as a mixed integer linear programming problem to minimize the total required backup link capacity. We prove that the decision version of backup network design problem is NP-complete. Given that network size will continue to increase, we introduce a heuristic approach of simulated annealing to solve the same problem. Numerical results show that the proposed scheme requires less total backup link capacity than the conventional scheme based on robust optimization.