Blar i NTNU Open på forfatter "Helvik, Bjarne Emil"

Viser treff 21-40 av 62

    • Effect of Communication Failures on State Estimation of 5G-Enabled Smart Grid 

      Zerihun, Tesfaye Amare; Garau, Michele; Helvik, Bjarne Emil (Peer reviewed; Journal article, 2020)
      Information and Communication Technologies (ICT), Wide Area Measurement Systems (WAMS) and state estimation represent the key-tools for achieving a reliable and accurate knowledge of the power grid, and represent the ...

    • Effect of Miner Incentive on the Confirmation Time of Bitcoin Transactions 

      Gebraselase, Befekadu Gezaheng; Helvik, Bjarne Emil; Jiang, Yuming (Chapter, 2021)
      Blockchain is a technology that provides a distributed ledger that stores previous records while maintaining consistency and security. Bitcoin is the first and largest decentralized electronic cryptographic system that ...

    • Evaluating Local Disaster Recovery Strategies 

      Oostenbrink, Jorik; Kuipers, Fernando; Heegaard, Poul Einar; Helvik, Bjarne Emil (Journal article; Peer reviewed, 2018)

    • Evaluating Quality of Experience in Videoconferencing Systems Based on Packet Loss 

      Kvistad, Ole Martin (Master thesis, 2008)
      Users of multimedia applications get more and more quality aware as the development of technologies progresses. When looking at videoconferencing it would be a great advantage knowing what level of quality a user experiences ...

    • Failure analysis and prediction in compound system by wavelets 

      Zerihun, Tesfaye Amare (Master thesis, 2016)
      The current overall ICT infrastructure mainly the Internet and Telecom networks can be looked upon as an ecosystem, which is the result of the cooperation between a huge number of Autonomous systems (ASes). The interconnection ...

    • Failure Process Characteristics of Cloud-Enabled Services 

      Tola, Besmir; Jiang, Yuming; Helvik, Bjarne Emil (Chapter; Peer reviewed, 2017)
      The design of cloud computing technologies need to guarantee high levels of availability and for this reason there is a large interest in new fault tolerant techniques that are able to keep the resilience of the systems ...

    • Fulfilling efficiently SLA availability guarantees in backbone networks 

      Tiwari, Prakriti (Master thesis, 2014)
      The availability and reliability of backbone networks is important tosociety. However, physical, software and unintentional human errorfailures affect the links and nodes in a backbone network. To overcomesuch failures in ...

    • GEARSHIFT: Guaranteeing availability requirements in SLAs using hybrid fault tolerance 

      Gonzalez, Andres Javier; Helvik, Bjarne Emil; Tiwari, Prakriti; Denis, Becker; Wittner, Otto Jonassen (Chapter, 2015)
      The dependability of ICT systems is vital for today's society. However, operational systems are not fault free. Providers and customers have to define clear availability requirements and penalties on the delivered services ...

    • A Holistic Approach to Dependability Modeling and Analysis of Smart Distribution Grids 

      Zerihun, Tesfaye Amare (Doctoral theses at NTNU;2021:56, Doctoral thesis, 2021)
      Lately, the distribution grid has been under a significant transformation, with a pervasive integration of Information and Communication Technology (ICT) for an enhanced operation and management of the grid. Some of the ...

    • Impact of SDN Controllers Deployment on Network Availability 

      Nencioni, Gianfranco; Helvik, Bjarne Emil; Gonzalez, Andres Javier; Heegaard, Poul Einar; Kamisinski, Andrzej (Research report, 2016)
      Software-defined networking (SDN) promises to improve the programmability and flexibility of networks, but it may bring also new challenges that need to be explored. The purpose of this technical report is to assess how ...

    • Implementing the Availability Model of a Software-Defined Backbone Network in Möbius 

      Nencioni, Gianfranco; Helvik, Bjarne Emil; Heegaard, Poul Einar (Research report, 2017)
      Software-defined networking (SDN) promises to im-prove the programmability and flexibility of networks, but it may bring also new challenges that need to be explored. One open issue is the quantitative ...

    • Including Failure Correlation in Availability Modeling of a Software-Defined Backbone Network 

      Nencioni, Gianfranco; Helvik, Bjarne Emil; Heegaard, Poul Einar (Journal article; Peer reviewed, 2017)
      Software-defined networking (SDN) promises to improve the programmability and flexibility of networks, but also brings new challenges that need to be explored. The main objective of this paper is to include failure correlation ...

    • Intelligent layer 2 switching by CE-ants 

      Antolí, Oriol (Master thesis, 2007)
      Living in Information Society, we always want to improve the networks to get more reliability, more bit rate, less ping . CE ant Layer 2 systems appear in order to change the concept of usual centralized networks, where ...

    • The Isolation Concept in the 5G Network Slicing 

      Gonzalez, Andres J.; Ordonez-Lucena, Jose; Helvik, Bjarne Emil; Nencioni, Gianfranco; Xie, Min; Lopez, Diego R.; Grønsund, Pål R. (Chapter, 2020)
      The fifth generation (5G) of cellular networks shall host a number of tenants and provide services tailored to meet a wide range of requirements in terms of performance, dependability and security. Network slicing will be ...

    • Managed Dependability in Interacting Systems 

      Helvik, Bjarne Emil; Nencioni, Gianfranco; Heegaard, Poul Einar; Wäfler, Jonas (Springer Series in Reliability Engineering;, Chapter; Peer reviewed, 2016)
      AdigitalICTinfrastructuremustbeconsideredasasystemofsystemsin itself, but also in interaction with other critical infrastructures such as water distributions, transportation (e.g. Intelligent Transport Systems) and Smart ...

    • Measurement Analysis and Improvement of rerouting in UNINETT 

      Skaland, Håkon (Master thesis, 2007)
      This thesis focuses on the analysis of the rerouting times in UNINETT, the Norwegian research network. Rerouting happens in case of a topology change of the network, and the routers have to calculate new paths to all ...

    • A Method for Performability Study on Wide Area Communication Architectures for Smart Grid 

      Amare, Tesfaye; Adrah, Charles Mawutor; Helvik, Bjarne Emil (Chapter, 2019)
      An extensive use of ICT is a key feature in the development of next generation smart grids. The ability of the ICT system to meet the real time requirements of the powers system, even when it is degraded due to failures, ...

    • Model-Driven Availability Assessment of the NFV-MANO with Software Rejuvenation 

      Tola, Besmir; Jiang, Yuming; Helvik, Bjarne Emil (Peer reviewed; Journal article, 2021)
      Network Function Virtualization enables network operators to modernize their networks with greater elasticity, network programmability, and scalability. Exploiting these advantages requires new and specialized designs for ...

    • Modeling and Evaluating NFV-Enabled Network Services under Different Availability Modes 

      Tola, Besmir; Nencioni, Gianfranco; Helvik, Bjarne Emil; Jiang, Yuming (Chapter, 2019)
      Network and Telecom operators are continuously embracing the adoption of Network Function Virtualization (NFV) as a means to provide more agile, flexible and cost-efficient services. Many telecommunication services need ...

    • Modelling the dependability in Network Function Virtualisation 

      Lin, Wenqi (Master thesis, 2017)
      Network Function Virtualization has been brought up to allow the TSPs to have more possibilities and flexibilities to provision services with better load optimizing, energy utilizing and dynamic scaling. Network functions ...