Research Outputs

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Now showing 1 - 10 of 23
  • Publication
    The Effect of the 802.11 Power Save Mechanism (PSM) on Energy Efficiency and Performance During System Activity
    (2012) ;
    Bhatti, S. N. 
    802.11 WLAN is a popular choice for wireless access on a range of ICT devices. A growing concern is the increased energy usage of ICT, for reasons of cost and environmental protection. The Power Save Mode (PSM) in 802.11 deactivates the wireless network interface during periods of inactivity. However, applications increasingly use push models, and so devices may be active much of the time. We have investigated the effectiveness of PSM, and considered its impact on performance when a device is active. Rather than concentrate on the NIC, we have taken a system-wide approach, to gauge the impact of the PSM from an application perspective. We experimentally evaluated performance at the packet level and system-wide power usage under various offered loads, controlled by packet size and data rate, on our 802.11n test bed. We have measured the system-wide power consumption corresponding to the individual traffic profiles and have derived application-specific effective energy-usage. We have found that in our scenarios, no significant benefit can be gained from using PSM.
      105Scopus© Citations 33
  • Publication
    Connected cars — Threats, vulnerabilities and their impact
    (IEEE, 2018-05) ; ;
    Schmittner, Christoph 
    ;
    ; ;
    Delsing, Jerker 
    The growing demand for interoperability between system components within a connected car has led to new security challenges in automotive development. The existing components, based on established technology, are often being combined to form such a connected car. For such established technologies, individual, often sector specific threat and vulnerability catalogs exist. The aim of this paper is to identify blocks of established technologies in a connected car and to consolidate the corresponding threat and vulnerability catalogs relevant for the individual constituent components. These findings are used to estimate the impact on specific system components and subsystems to identify the most crucial components and threats.
    Scopus© Citations 14  212
  • Publication
    Towards continuous Cloud Service Assurance for Critical Infrastructure IT
    (2014-08-27)
    Hudic, A. 
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    Mauthe, A. 
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    Caceres, S. 
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    Hecht, T. 
    ;
    The momentum behind Cloud Computing has revolutionized how ICT services are provided, adopted and delivered. Features such as high scalability, fast provisioning, on demand resource availability makes it an attractive proposition for deploying complex and demanding systems. Clouds are also very suitable for deploying systems with unpredictable load patterns including Critical infrastructure services. Though, the major obstacle in hosting Critical infrastructures is often a lack of assurance. The transparency and flexibility offered by the Cloud, abstracts per definition over e.g. data placement, hardware, service migration. This makes it very hard to assure security properties. We present an investigation of assurance approaches, an analysis of their suitability for Critical Infrastructure Services being deployed in the Cloud and presents our approach.
      119Scopus© Citations 8
  • Publication
    Application Level Energy and Performance Measurements in a Wireless LAN
    (2011) ;
    Bhatti, S. N. 
    ;
    Yu, Y. 
    We present an experimental evaluation of energy usage and performance in a wireless LAN cell based on a test bed using the 5 GHz ISM band for 802.11a and 802.11n. We have taken an application-level approach, by varying the packet size and transmission rate at the protocol level and evaluating energy usage across a range of application transmission rates using both large and small packet sizes. We have observed that both the application's transmission rate and the packet size have an impact on energy efficiency for transmission in our test bed. We also included in our experiments evaluation of the energy efficiency of emulations of YouTube and Skype flows, and a comparison with Ethernet transmissions.
      141Scopus© Citations 23
  • Publication
    Towards a Security Baseline for IaaS-Cloud Back-Ends in Industry 4.0
    The popularity of cloud based Infrastructure-as-a- Service (IaaS) solutions is becoming increasingly popular. However, since IaaS providers and customers interact in a flexible and scalable environment, security remains a serious concern. To handle such security issues, defining a set of security parameters in the service level agreements (SLA) between both, IaaS provider and customer, is of utmost importance. In this paper, the European Network and Information Security Agency (ENISA) guidelines are evaluated to extract a set of security parameters for IaaS. Furthermore, the level of applicability and implementation of this set is used to assess popular industrial and open-source IaaS cloud platforms, respectively VMware and OpenStack. Both platforms provide private clouds, used as backend infrastructures in Industry 4.0 application scenarios. The results serve as initial work to identify a security baseline and research needs for creating secure cloud environments for Industry 4.0.
    Scopus© Citations 4  171
  • Publication
    Categorization of Standards, Guidelines and Tools for Secure System Design for Critical Infrastructure IT in the Cloud
    (2015)
    Paudel, S. 
    ;
    ;
    Wagner, C. 
    ;
    Hudic, A. 
    ;
    Ng, Wee-Kong 
    With the increasing popularity of cloud computing, security in cloud-based applications is gaining awareness and is regarded as one of the most crucial factors for the long term success of such applications. Despite all benefits of cloud computing, its fate lies in its success in gaining trust from its users achieved by ensuring cloud services being built in a safe and secure manner. This work evaluates existing security standards and tools for creating Critical Infrastructure (CI) services in cloud environments -- often implemented as cyber physical systems (CPS). We also identify security issues from a literature review and from a show case analysis. Furthermore, we analyse and evaluate how mitigation options for identified open security issues for CI in the cloud point to individual aspects of standards and guidelines to support the creation of secure CPS/CI in the cloud. Additionally, we presented the results in a multidimensional taxonomy based on the mapping of the issues and the standards and tools. We show which areas require the attention as they are currently not covered completely by existing standards, guidelines and tools.
      138Scopus© Citations 2
  • Publication
    Generic Autonomic Management as a Service in a SOA-based Framework for Industry 4.0
    (IEEE, 2019-10) ; ;
    Delsing, Jerker 
    Cyber-physical production systems are engineered systems that are built from, and depend upon, the seamless integration of computational algorithms and physical components. In order to make these systems interoperable with each other for addressing Industry 4.0 applications a number of service-oriented architecture frameworks are developed. Such frameworks are composed by a number of services, which are inherently dynamic by nature and thus imply the need for self-adaptation. In this paper we propose generic autonomic management as a service and show how it can be integrated in the Arrowhead framework. We propose generic and reusable interfaces for each phase of the autonomic control loop in order to increase the usability of the service for other frameworks and application systems, while reducing the software engineering effort. To show the utility of our approach in the Arrowhead framework we use a climate control application as a representative example.
    Scopus© Citations 10  424
  • Publication
    Trustworthy Evidence Gathering Mechanism for Multilayer Cloud Compliance.
    (2014)
    Florian, M. 
    ;
    Paudel, S. 
    ;
    Cloud Computing allows the designing of systems which dynamically acquire compute resources. This makes it very suitable for Critical Infrastructures where unpredictable load due to human usage patterns are very likely. Especially in this domain legal compliance is a growing concern in general. Abstraction over multiple architectural cloud layers allows for individual layers being operated by different providers. This makes it hard to determine whether legal compliance is given. In this paper we motivate the research towards an Event Gathering Mechanism which is envisioned to allow the modelling of legal aspects in a multi layered cloud environment.
    Scopus© Citations 6  92