Browsing NTNU Open by Author "Helvik, Bjarne Emil"
Now showing items 1-20 of 61
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A Fault-Tolerant and Consistent SDN Controller
Kamisinski, Andrzej; Gonzalez, Andres Javier; Helvik, Bjarne Emil; Nencioni, Gianfranco (Chapter, 2016)Software-Defined Networking (SDN) is a new paradigm that promises to enhance network flexibility and innovation. However, operators need to thoroughly assess its advantages and threats before they can implement it. Robustness ... -
A modeling approach for dependability analysis of smart distribution grids
Zerihun, Tesfaye Amare; Helvik, Bjarne Emil; Heegaard, Poul Einar (Chapter, 2018)The distribution grids are among the most critical infrastructures which integrates advanced control and communication technologies atop of power systems. This paper presents a comprehensive modeling framework suited to ... -
Achieving dependability in software-defined networking - a perspective
Helvik, Bjarne Emil; Heegaard, Poul Einar; Mendiratta, Veena (Chapter, 2015)In this paper we take a closer look at the operationof software defined networking (SDN) in intra-domain networks.The focus is on the dependability issues related to interworking ofSDN controllers, network OS (NOS), and ... -
An Empirical Study of Software Reliability in SDN Controllers
Vizarreta, Petra; Trivedi, Kishor; Helvik, Bjarne Emil; Heegaard, Poul Einar; Kellerer, Wolfgang; Mas Machuca, Carmen (Chapter, 2017)Software Defined Networking (SDN) exposes critical networking decisions, such as traffic routing or enforcement of the critical security policies, to a software entity known as the SDN controller. Controller software, as ... -
Analysis of MANO design approaches with respect to dependability in a 5G isolated sliced environment.
Vikre, Hanne Randal (Master thesis, 2020)Den femte generasjonen (5G) av mobilteknologi er tenkt å være et viktig steg i utviklingen av kommunikasjonsteknologi. En av de viktige komponentene i et velfungerende 5G-system er dets administrasjons og orkestreringssystem. ... -
Analysis of the effect of InfoRanking on content pollution in peer-to-peer systems
Zhang, Peiqing; Fotiou, Nikos; Helvik, Bjarne Emil; Marias, Giannis F.; Polyzos, George C. (Journal article; Peer reviewed, 2014)Content pollution is one of the most common attacks against peer-to-peer file-sharing systems. As such, systems are usually open to users, and the deployed security mechanisms merely examine the sanity of the downloaded ... -
An Analysis of Transaction Handling in Bitcoin
Gebraselase, Befekadu Gezaheng; Helvik, Bjarne Emil; Jiang, Yuming (Chapter, 2021)Bitcoin has become the leading cryptocurrency system, but the limit on its transaction processing capacity has resulted in increased transaction fee and delayed transaction confirmation. As such, it is pertinent to understand ... -
Assessing the maturity of SDN controllers with software reliability growth models
Vizarreta, Petra; Trivedi, Kishor; Helvik, Bjarne Emil; Heegaard, Poul Einar; Blenk, Andreas; Kellerer, Wolfgang; Mas Machuca, Carmen (Journal article; Peer reviewed, 2018)In software defined networking (SDN), critical control plane functions are offloaded to a software entity known as the SDN controller. Today's SDN controllers are complex software systems, owing to heterogeneity of networks ... -
Assessing the risk of violating SLA dependability requirements in software-defined networks
Kamisiński, Andrzej; Helvik, Bjarne Emil; Gonzalez, Andres Javier; Nencioni, Gianfranco (Chapter; Peer reviewed, 2017)Dependability of computer and communication networks is an important aspect of the customer-provider relationship in the telecommunication industry. Considering the increasing interest in Software-Defined Networking (SDN) ... -
Availability Modelling of Software-Defined Backbone Networks
Kamisinski, Andrzej; Gonzalez, Andres Javier; Helvik, Bjarne Emil; Nencioni, Gianfranco; Heegaard, Poul Einar (Chapter, 2016)Software-Defined Networking (SDN) promises to improve the programmability and flexibility of networks, but it may also bring new challenges that need to be explored. The main objective of this paper is to present a ... -
Banken i skyen - fremtidige trender og scenarioer for skytjenester i banksektoren
Jeyaseelan, Sutharsan (Master thesis, 2014)Bruk av finansielle tjenester er sterkt utbredt i dagens moderne samfunn. Den finansielle infrastrukturen i Norge prosesserte i 2013 daglig et gjennomsnitt på 203 milliarder kroner. Mens andre sektorer og industrier ... -
Bitcoin P2P Network Measurements: A testbed study of the effect of peer selection on transaction propagation and confirmation times
Gebraselase, Befekadu; Helvik, Bjarne Emil; Jiang, Yuming (Peer reviewed; Journal article, 2022)Bitcoin is the first and the most extensive decentralized electronic cryptocurrency system that uses blockchain technology. It uses a peer-to-peer (P2P) network to operate without a central authority and propagate system ... -
Blockchain Support For Time-Critical Self-Healing In Smart Distribution Grids
Gebraselase, Befekadu; Adrah, Charles Mawutor; Zerihun, Tesfaye Amare; Helvik, Bjarne Emil; Heegaard, Poul Einar (Chapter, 2022)Smart distribution grids have new protection concepts known as fault self-healing whereby Intelligent Electronic Devices (IEDs) can automatically reconfigure the power circuits to isolate faults and restore power to the ... -
Co-simulation and Discrete Event Simulation for Reliability Assessment of Power System and ICT: A Comparison
Garau, Michele; Muka, Romina; Heegaard, Poul Einar; Helvik, Bjarne Emil (Chapter, 2021)Modern power systems are increasingly relying on Information and Communication Technologies (ICT) to support their operation. This digitalization process introduces new complexity, which requires novel methodologies to ... -
Cost comparison studies of different network platforms: OpEx modeling and analysis
Moe, Øyvind Solberg (Master thesis, 2007)The importance of Operational Expenditures (OpEx) on the overall network cost has been shown in recent studies. This master thesis is part of a series of techno economical studies focused on the evaluation of OpEx and the ... -
Dependability Analysis of Smart Distribution Grid Architectures Considering Various Failure Modes
Zerihun, Tesfaye Amare; Helvik, Bjarne Emil (Chapter, 2018)The future smart distribution grid will be consisting of new components and technologies with enhanced capability whose failure behaviour can not be determined with certainty. In studying the reliability of these distribution ... -
Dependability modelling of Jgroup/ARM
Sæstad, Ane (Master thesis, 2008)In the later years, fault tolerant distributed systems have been applied to a variety of network internal and external services. Keeping distributed systems consistent and fault tolerant require management functionality. ... -
Dependability of the NFV Orchestrator: State of the Art and Research Challenges
Gonzalez, Andres Javier; Nencioni, Gianfranco; Kamisinski, Andrzej; Helvik, Bjarne Emil; Heegaard, Poul Einar (Journal article; Peer reviewed, 2018)The introduction of network function virtualisation (NFV) represents a significant change in networking technology, which may create new opportunities in terms of cost efficiency, operations, and service provisioning. ... -
Design and Implementation of an Efficient, Reliable and Safe Work-Package Database System at CERN
Riksem, Hans-Even Ramsevik (Master thesis, 2010)The Activity Coordination Tool (ACT) is a web application designed to automate theplanning and coordination of work packages. In the CMS experiment at CERN it isimportant that work packages in the underground facilities ... -
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 ...