| 1. |
- Aguiar, Javier, et al.
(författare)
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New Data Communication Standards
- 2012
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Ingår i: IEEE Communications Magazine. - 0163-6804. ; 50:3, s. 70-71
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Akbarian, Fatemeh, et al.
(författare)
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A Security Framework in Digital Twins for Cloud-based Industrial Control Systems: Intrusion Detection and Mitigation
- 2021
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Ingår i: 2021 26th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA ). - 9781728129891 - 9781728129907
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Konferensbidrag (refereegranskat)abstract
- With the help of modern technologies and advances in communication systems, the functionality of Industrial control systems (ICS) has been enhanced leading toward to have more efficient and smarter ICS. However, this makes these systems more and more connected and part of a networked system. This can provide an entry point for attackers to infiltrate the system and cause damage with potentially catastrophic consequences. Therefore, in this paper, we propose a digital twin-based security framework for ICS that consists of two parts: attack detection and attack mitigation. In this framework we deploy an intrusion detection system in digital domain that can detect attacks in a timely manner. Then, using our mitigation method, we keep the system stable with acceptable performance during the attack. Additionally, we implement our framework on a real testbed and evaluate its capability by subjecting it to a set of attacks.
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| 3. |
- Akbarian, Fatemeh, et al.
(författare)
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Attack Resilient Cloud-Based Control Systems for Industry 4.0
- 2023
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Ingår i: IEEE Access. - 2169-3536. ; 11, s. 27865-27882
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, since the cloud can provide tremendous advantages regarding storage and computing resources, the industry has been motivated to move industrial control systems to the cloud. However, the cloud also introduces significant security challenges since moving control systems to the cloud can enable attackers to infiltrate the system and establish an attack that can lead to damages and disruptions with potentially catastrophic consequences. Therefore, some security measures are necessary to detect these attacks in a timely manner and mitigate their impact. In this paper, we propose a security framework for cloud control systems that makes them resilient against attacks. This framework includes three steps: attack detection, attack isolation, and attack mitigation. We validate our proposed framework on a real testbed and evaluate its capability by subjecting it to a set of attacks. We show that our proposed solution can detect an attack in a timely manner and keep the plant stable, with high performance during the attack.
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| 4. |
- Akbarian, Fatemeh, et al.
(författare)
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Demonstration: A cloud-control system equipped with intrusion detection and mitigation
- 2021
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Ingår i: The Conference on Networked Systems (NetSys 2021).
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Konferensbidrag (refereegranskat)abstract
- The cloud control systems (CCs) are inseparable parts of industry 4.0. The cloud, by providing storage and computing resources, allows the controllers to evaluate complex problems that are too computationally demanding to perform locally. However, connecting physical systems to the cloud through the network can provide an entry point for attackers to infiltrate the system and cause damage with potentially catastrophic consequences. Hence, in this paper, we present a demo of our proposed security framework for CCs and demonstrate how it can detect attacks on this system quickly and mitigate them.
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| 5. |
- Akbarian, Fatemeh, et al.
(författare)
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Detecting and Mitigating Actuator Attacks on Cloud Control Systems through Digital Twins
- 2023
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Ingår i: The 31st International Conference on Software, Telecommunications and Computer Networks (SoftCOM 2023). - 9798350301076
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Konferensbidrag (refereegranskat)abstract
- Recently, the industry has been driven to move industrial control systems to the cloud due to the significant advantages it offers in terms of storage and computing resources. However, this shift also brings forth significant security challenges. By moving control systems to the cloud, the potential for attackers to infiltrate the system and launch damaging attacks increases. These attacks can result in severe disruptions and potentially catastrophic consequences. Hence, attack detection and mitigation mechanisms are crucial for cloud control systems. In this paper, we present an approach that leverages the digital twins concept and virtual actuator method to detect and mitigate deception attacks on control signals within cloud control systems. By conducting experiments on a real testbed and subjecting it to a set of attacks, we validate the effectiveness of our solution. Our proposed method successfully detects attacks in a timely manner and keeps the plant stable, with a good performance during the attack.
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| 6. |
- Akbarian, Fatemeh, et al.
(författare)
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Detection and mitigation of deception attacks on cloud-based industrial control systems
- 2022
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Ingår i: 25th Conference on Innovation in Clouds, Internet and Networks (ICIN). - 9781728186887
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Konferensbidrag (refereegranskat)abstract
- In recent years, because the cloud can provide huge advantages regarding storage and computing resources, industry has been motivated to move industrial control systems to the cloud. However, the cloud also introduces major security challenges, since moving control systems to the cloud can enable attackers to infiltrate the system and establish an attack that can lead to damages and disruptions with potentially catastrophic consequences. Therefore, intrusion detection and mitigation mechanisms are crucial for cloud-based industrial control systems. In this paper, we propose a method for detection and mitigation of deception attacks on actuator signals in cloud-based industrial control systems. We validate our solution on a real testbed and evaluate its capability by subjecting it to a set of attacks. Our proposed solution can detect the attack in a timely manner and keep the plant stable, with an acceptable performance during the attack.
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| 7. |
- Akbarian, Fatemeh, et al.
(författare)
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Intrusion Detection in Digital Twins for Industrial Control Systems
- 2020
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Ingår i: 2020 International Conference on Software, Telecommunications and Computer Networks (SoftCOM). - 9789532900996
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Konferensbidrag (refereegranskat)abstract
- Nowadays, the growth of advanced technologies is paving the way for Industrial Control Systems (ICS) and making them more efficient and smarter. However, this makes ICS more connected to communication networks that provide a potential platform for attackers to intrude into the systems and cause damage and catastrophic consequences. In this paper, we propose implementing digital twins that have been equipped with an intrusion detection algorithm. Our novel algorithm is able to detect attacks in a timely manner and also diagnose the type of attack by classification of different types of attacks. With digital twins, which are a new concept in ICS, we have virtual replicas of physical systems so that they precisely mirror the internal behavior of the physical systems. So by placing the intrusion detection algorithm in digital twins, security tests can be done remotely without risking negative impacts on live systems.
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| 8. |
- Akbarian, Fatemeh, et al.
(författare)
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Resilient Cloud Control System: Dynamic Frequency Adaptation via Q-learning
- 2024
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Ingår i: 27th Conference on Innovation in Clouds, Internet and Networks (ICIN). - 9798350393774 - 9798350393767
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Konferensbidrag (refereegranskat)abstract
- Traditional control systems face challenges in managing high data loads and computing power, prompting the evolution of Cloud Control Systems (CCS)-a fusion of Networked Control Systems (NCS) and cloud computing. Despite offering manifold advantages, CCS encounters hurdles in navigating the dynamic cloud environment characterized by fluctuating workloads, rendering static frequency settings inefficient. Moreover, the optimal utilization of cloud resources poses a pivotal challenge within CCS operations. To address these, the paper proposes a resilient CCS by adapting system frequency dynamically. Leveraging Q-learning, the approach measures Round Trip Time (RTT) and system output errors, dynamically adjusting the system's frequency to minimize control costs, optimize performance within the dynamic cloud environment, and achieve resource frugality, minimizing resource usage. Through real testbed experiments, this paper evaluates and analyzes the effectiveness of the proposed method, aiming to establish an adaptive and efficient control framework aligned with evolving cloud dynamics.
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| 9. |
- Akbarian, Fatemeh, et al.
(författare)
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Synchronization in Digital Twins for Industrial Control Systems
- 2020
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Konferensbidrag (refereegranskat)abstract
- Digital twins, which are a new concept in industrial control systems (ICS), play a key role in realizing the vision of a smart factory, and they can have different effective use cases. With digital twins, we have virtual replicas of physical systems so that they precisely mirror the internal behavior of the physical systems. Hence, synchronization is necessary to keep the states of digital twins in sync with those of their physical counterparts. Otherwise, their behavior may be different from each other, and it can lead to wrong decisions about the system that can have catastrophic consequences. In this paper, we propose three different architectures for digital twins, and then by investigating their ability to follow the physical system’s behavior, we will determine the best architecture, whose output has the lowest error compared with the physical system’s output.
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| 10. |
- Ali-Eldin, Ahmed, 1985-, et al.
(författare)
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Analysis and characterization of a Video-on-Demand service workload
- 2015
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Ingår i: Proceedings of the 6th ACM Multimedia Systems Conference, MMSys 2015. - New York, NY, USA : ACM Digital Library. - 9781450333511 ; , s. 189-200
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Konferensbidrag (refereegranskat)abstract
- Video-on-Demand (VoD) and video sharing services accountfor a large percentage of the total downstream Internet traf-fic. In order to provide a better understanding of the loadon these services, we analyze and model a workload tracefrom a VoD service provided by a major Swedish TV broad-caster. The trace contains over half a million requests gener-ated by more than 20000 unique users. Among other things,we study the request arrival rate, the inter-arrival time, thespikes in the workload, the video popularity distribution, thestreaming bit-rate distribution and the video duration distri-bution. Our results show that the user and the session ar-rival rates for the TV4 workload does not follow a Poissonprocess. The arrival rate distribution is modeled using a log-normal distribution while the inter-arrival time distributionis modeled using a stretched exponential distribution. Weobserve the “impatient user” behavior where users abandonstreaming sessions after minutes or even seconds of startingthem. Both very popular videos and non-popular videos areparticularly affected by impatient users. We investigate ifthis behavior is an invariant for VoD workloads.
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| 11. |
- Ali-Eldin, Ahmed, et al.
(författare)
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Efficient provisioning of bursty scientific workloads on the cloud using adaptive elasticity control
- 2012
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Ingår i: Proceedings of the 3rd workshop on Scientific Cloud Computing Date. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450313407 - 145031340X ; , s. 31-40
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Konferensbidrag (refereegranskat)abstract
- Elasticity is the ability of a cloud infrastructure to dynamically change theamount of resources allocated to a running service as load changes. We build anautonomous elasticity controller that changes the number of virtual machinesallocated to a service based on both monitored load changes and predictions offuture load. The cloud infrastructure is modeled as a G/G/N queue. This modelis used to construct a hybrid reactive-adaptive controller that quickly reactsto sudden load changes, prevents premature release of resources, takes intoaccount the heterogeneity of the workload, and avoids oscillations. Using simulations with Web and cluster workload traces, we show that our proposed controller lowers the number of delayed requests by a factor of 70 for the Web traces and 3 for the cluster traces when compared to a reactive controller. Ourcontroller also decreases the average number of queued requests by a factor of 3 for both traces, and reduces oscillations by a factor of 7 for the Web traces and 3 for the cluster traces. This comes at the expense of between 20% and 30% over-provisioning, as compared to a few percent for the reactive controller.
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| 12. |
- Ali-Eldin, Ahmed, 1985-, et al.
(författare)
-
WAC : A Workload analysis and classification tool for automatic selection of cloud auto-scaling methods
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Autoscaling algorithms for elastic cloud infrastructures dynami-cally change the amount of resources allocated to a service ac-cording to the current and predicted future load. Since there areno perfect predictors, no single elasticity algorithm is suitable foraccurate predictions of all workloads. To improve the quality ofworkload predictions and increase the Quality-of-Service (QoS)guarantees of a cloud service, multiple autoscalers suitable for dif-ferent workload classes need to be used. In this work, we intro-duce WAC, a Workload Analysis and Classification tool that as-signs workloads to the most suitable elasticity autoscaler out of aset of pre-deployed autoscalers. The workload assignment is basedon the workload characteristics and a set of user-defined Business-Level-Objectives (BLO). We describe the tool design and its maincomponents. We implement WAC and evaluate its precision us-ing various workloads, BLO combinations and state-of-the-art au-toscalers. Our experiments show that, when the classifier is tunedcarefully, WAC assigns between 87% and 98.3% of the workloadsto the most suitable elasticity autoscaler.
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| 13. |
- Ali-Eldin, Ahmed, 1985-, et al.
(författare)
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Workload Classification for Efficient Auto-Scaling of Cloud Resources
- 2013
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Elasticity algorithms for cloud infrastructures dynamically change the amount of resources allocated to a running service according to the current and predicted future load. Since there is no perfect predictor, and since different applications’ workloads have different characteristics, no single elasticity algorithm is suitable for future predictions for all workloads. In this work, we introduceWAC, aWorkload Analysis and Classification tool that analyzes workloads and assigns them to the most suitable elasticity controllers based on the workloads’ characteristics and a set of business level objectives.WAC has two main components, the analyzer and the classifier. The analyzer analyzes workloads to extract some of the features used by the classifier, namely, workloads’ autocorrelations and sample entropies which measure the periodicity and the burstiness of the workloads respectively. These two features are used with the business level objectives by the clas-sifier as the features used to assign workloads to elasticity controllers. We start by analyzing 14 real workloads available from different applications. In addition, a set of 55 workloads is generated to test WAC on more workload configurations. We implement four state of the art elasticity algorithms. The controllers are the classes to which the classifier assigns workloads. We use a K nearest neighbors classifier and experiment with different workload combinations as training and test sets. Our experi-ments show that, when the classifier is tuned carefully, WAC correctly classifies between 92% and 98.3% of the workloads to the most suitable elasticity controller.
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| 14. |
- Amani, Payam, et al.
(författare)
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Application of Control Theory to a Commercial Mobile Service Support System
- 2012
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Ingår i: International Journal on Advances in Telecommunications. - 1942-2601. ; 5:3&4
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Tidskriftsartikel (refereegranskat)abstract
- The Mobile Service Support system (MSS), which Ericsson AB develops, handles the setup of new subscribers and services into a mobile network. Experience from deployed systems show that traffic monitoring and control of the system will be crucial for handling overload situations that may occur at sudden traffic surges. In this paper we identify and explore some important control challenges for this type of systems. Further, we present analysis and experiments showing some advantages of proposed solutions. First, we develop a load-dependent server model for the system, which is validated in testbed experiments. Further, we propose a control design based on the model, and a method for estimation of response times and arrival rates. The main contribution of this paper is that we show how control theory methods and analysis can be used for commercial telecom systems. Parts of our results have been implemented in commercial products, validating the strength of our work.
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| 15. |
- Amani, Payam, et al.
(författare)
-
Multi-step ahead response time prediction for single server queuing systems
- 2011
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Ingår i: [Host publication title missing].
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Konferensbidrag (refereegranskat)abstract
- Multi-step ahead response time prediction of CPU constrained computing systems is vital for admission control, overload protection and optimization of resource allocation in these systems. CPU constrained computing systems such as web servers can be modeled as single server queuing systems. These systems are stochastic and nonlinear. Thus, a well-designed nonlinear prediction scheme would be able to represent the dynamics of such a system much better than a linear scheme. A nonlinear autoregressive neural network with exogenous inputs based multi-step ahead response time predictor has been developed. The proposed estimator has many promising characteristics that make it a viable candidate for being implemented in admission control products for computing systems. It has a simple structure, is nonlinear, supports multi-step ahead prediction, and works very well under time variant and non-stationary scenarios such as single server queuing systems under time varying mean arrival rate. Performance of the proposed predictor is evaluated through simulation. Simulations show that the proposed predictor is able to predict the response times of single server queuing systems in multi-step ahead with very good precision represented by very small mean absolute and mean squared prediction errors.
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| 16. |
- Amani, Payam, et al.
(författare)
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NARX-based multi-step ahead response time prediction for database servers
- 2011
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Ingår i: [Host publication title missing]. - 2164-7143. - 9781457716768 ; , s. 813-818
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Konferensbidrag (refereegranskat)abstract
- Advanced telecommunication applications are often based on a multi-tier architecture, with application servers and database servers. With a rapidly increasing development of cloud computing and data centers, characterizations of the dynamics for database servers during changing workloads will be a key factor for analysis and performance improvements in these applications. We propose a multi-step ahead response time predictor for database queries based on a nonlinear autoregressive neural network model with exogenous inputs. The estimator shows many promising characteristics which make it a viable candidate for being implemented in admission control products for database servers. Performance of the proposed predictor is evaluated through experiments on a lab setup with a MySQL-server.
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| 17. |
- Andersson, Jens A, et al.
(författare)
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Analytic Model for Cross-Layer Dependencies in VDSL2 access networks
- 2014
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Ingår i: 22nd International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 2014. - 9781479964970 - 9789532900521 ; , s. 269-273
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Konferensbidrag (refereegranskat)abstract
- Recent changes in user employment of Internet based services, new deployment technologies for mobile networks as well as an ongoing realisation of fixed and mobile converged networks e.g. the EU FP7 project COMBO, are significant examples of enablers for increasing demands on DSL links. Investigating cross-layer dependencies between all layers in the OSI reference model becomes increasingly important. In this paper we present an analytical model and experimental results for the relation between impulse noise on a VDSL2 link and the effect this have on the network layer packet loss. We show how the packet loss rate is dependent not only on the disturbance signal level and periodicity but also on the link utilisation.
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| 18. |
- Andersson, Jens A, et al.
(författare)
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Impact of DSL link impairments on higher layer QoS parameters
- 2012
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Ingår i: Proceedings of SNCNW 2012. ; , s. 95-98
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Konferensbidrag (refereegranskat)abstract
- An increasing demand from e.g. real-time multimedia applications (IPTV, OTT) adds strains on especially DSL based access links. In this paper we argue why it is important to study DSL link impairments and their impact on QoS parameters on higher layers. We discuss the need for establishing methods for quality of service estimation with cross layer techniques and present some initial results.
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| 19. |
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| 20. |
- Andersson, Jens A, et al.
(författare)
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User profiling for pre-fetching or caching in a catch-up TV network
- 2016
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Ingår i: 2016 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB). - 9781467390446
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Konferensbidrag (refereegranskat)abstract
- We investigate the potential of different pre-fetching and/or caching strategies for different user behaviour with respect to surfing or browsing in a catch-up-TV network. To this end we identify accounts and channels associated with strong or weak surfing or browsing respectively and study the distributions of hold times for the different types of behaviour. Finally we present results from a request prediction model and a caching simulation for the different types of behaviour and find that the results are relatively similar.
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| 21. |
- Andersson, Jens K, et al.
(författare)
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Convergence-analysis of the internet and the telecommunication architectures
- 2002
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Ingår i: Sixteenth Nordic Teletraffic Seminar NTS 16 : Helsinki University of Technology, Espoo August 21-23, 2002 : proceedings (Report / Helsinki University of Technology, Networking Laboratory, ISSN 1458-0322).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The convergence of the Internet and Telecommunication Architectures is a key issue in today’s telecommunication world. It is foreseen that future versions of UMTS will be all-IP based, and therefore the interest in this area is increasing. The focus in this paper is to show how to access IN-services from the Internet and other IP-based networks. Previous research of the interworking between PSTN and IP-networks will be discussed. The respective advantages of different architectures are presented and some solutions of building a bridge between the protocols used in these networks are described. Further, this paper presents some of the performance problems that may occur in such systems.
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| 22. |
- Andersson, Jens K, et al.
(författare)
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Load Balancing and Admission Control of a Parlay X Application Server
- 2004
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Ingår i: Seventeenth Nordic Teletraffic Seminar, NTS 17, Fornebu, Norway, 25-27 August 2004. - 8242305951
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Konferensbidrag (refereegranskat)abstract
- To increase the number of services and applications in the telecommunication networks a new service architecture has been proposed and specified. The consortia that initiated the new service architecture is called Parlay. Since then, there has been a continued development and 3GPP the standardization group for 3G networks, is now cooperating with Parlay. 3GPP and Parlay are together specifying the Parlay/OSA standard. However, the aim with the new service architecture is to make the art of service development so easy that any software developer should be a potential application developer for telecommunication networks. It is foreseen to be a dramatic increase of new services, but it has been shown that it is still complex to create new applications. Parlay X is a standard which is an extension of Parlay/OSA, initiated to allow access to the telecommunication network capabilities via web services. The Parlay X architectures include an Application Server (AS), which translates the web service calls to Parlay/OSA commands. A typical AS is a distributed environment sensitive to overload. In this paper we propose and investigate an overload control mechanisms for an AS. The methods have been implemented in a real AS to evaluate the performance. Parlay X is a contract driven architecture, where different service providers have different constraints about minimum number of service calls served per second and maximal delays of different services. The methods and algorithms are designed to serve different service providers with different contract parameters.
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| 23. |
- Andersson, Jens K, et al.
(författare)
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Performance analysis and modelling of an OSA gateway
- 2003
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Ingår i: Personal Wireless Communications / Lecture Notes in Computer Science. - 0302-9743 .- 1611-3349. - 9783540201236 ; 2775, s. 511-517
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Konferensbidrag (refereegranskat)abstract
- It is foreseen that you in the future should be able to use the same services independent of where you are positioned or which terminal that is used. The open service architectures provide these opportunities. Open Service Access (OSA) is an example of such an architecture and it is part of the specification delivered by 3GPP. This paper explains the OSA architecture and presents a model of an OSA gateway. Further, it discusses and proposes some feasible overload control mechanisms for the gateway. The behaviour of the mechanisms is investigated through simulation.
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| 24. |
- Andersson, Jens K, et al.
(författare)
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Performance analysis and overload control of an open service access (OSA) architecture
- 2003
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Ingår i: Performance and control of next-generation communication networks : [ITCom's Conference on Performance and Control of Next-Generation Communication Networks] ; 9 - 10 September 2003, Orlando, Florida, USA (SPIE proceedings series). - : SPIE. - 0819451274 ; 5244, s. 176-186
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Konferensbidrag (refereegranskat)abstract
- The trend of the service architectures developed in telecommunications today is that they should be open in the sense thatthey can communicate over the borders of different networks. Instead of each network having their own service architecture with their own applications, all networks should be able to use the same applications. 3GPP, the organization developing specifications for the 3G networks has specified the standard Open Service Access (OSA), as a part of the 3G specification. OSA offers different Application Protocol Interfaces that enable an application that resides outside a network to use the capabilities of the network. This paper analyses the performance of an OSA gateway. It is examined how the overload control can be dealt with in a way to best satisfy the operators and the 3'rd parties. There are some guiding principles in the specifications, but a lot of decisions have to be made by the implementors of application servers and OSA gateways. Proposals of different requirements for an OSA architecture exist such as, minimum amount of accepted calls per second and time constraint for the maximal total delay for an application. Maximal and fair throughput have to be prioritized from the 3'rd parties view, but profit is the main interest from the operators point of view. Therefore this paperexamines a priority based proposal of an overload control mechanism taking these aspects and requirements into account.
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| 25. |
- Andersson, Jens K, et al.
(författare)
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Priorities and overload control in OSA
- 2003
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Ingår i: Fourth International Conference on 3G Mobile Communication Technologies (3G 2003) : 25 - 27 June 2003, Savoy Place, London, UK (IEE Conference Publications ; vol. 494). - : IEE. - 085296756X ; , s. 139-143
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Konferensbidrag (refereegranskat)abstract
- An Open Service Access (OSA) gateway is modelled in a multi application environment. Also, an overload control mechanism is proposed. The mechanism supports different time constraints and priorities for the applications. By simulations it is shown how the proposed overload control works during different load conditions in the modelled environment.
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