| 1. |
- Beltramelli, Luca, et al.
(författare)
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Hybrid MAC Mechanism for Energy Efficient Communication in IEEE 802.11ah
- 2017
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Ingår i: Proceedings of the 2017 IEEE International Conference on Industrial Technology (ICIT). - : IEEE. - 9781509053209 ; , s. 1295-1300
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Konferensbidrag (refereegranskat)abstract
- Many applications for machine-to-machine (M2M) communications are characterized by large numbers of devices with sporadic transmissions and subjected to low energy budgets. This work addresses the importance of energy consumption by proposing a new Medium Access Control (MAC) mechanism for improving the energy efficiency of IEEE 802.11ah, a standard targeting M2M communication. We propose to use the features of IEEE 802.11ah MAC to realize a hybrid contention-reservation mechanism for the transmission of uplink traffic. In the proposed mechanism, any device with a buffered packet will first notify the Access Point (AP) during a contention phase before being given a reserved timeslot for the data transmission. We develop a mathematical model to analyse the energy consumption ofthe proposed mechanism and of IEEE 802.11ah. The results show that for a monitoring scenario, the proposed contention reservation mechanism reduces the energy consumption for a successful uplink data transmission by up to 55%.
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| 2. |
- Beltramelli, Luca, et al.
(författare)
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Interference Modelling in a Multi-Cell LoRa System
- 2018
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Ingår i: 2018 14th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob). - : IEEE. - 9781538668764
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Konferensbidrag (refereegranskat)abstract
- As the market for low-power wide-area network (LPWAN) technologies expands and the number of connected devices increases, it is becoming important to investigate the performance of LPWAN candidate technologies in dense deployment scenarios. In dense deployments, where the networks usually exhibit the traits of an interference-limited system, a detailed intra- and inter-cell interference analysis of LPWANs is required. In this paper, we model and analyze the performance of uplink communication of a LoRa link in a multi-cell LoRa system. To such end, we use mathematical tools from stochastic geometry and geometric probability to model the spatial distribution of LoRa devices. The model captures the effects of the density of LoRa cells and the allocation of quasi-orthogonal spreading factors (SF) on the success probability of the LoRa transmissions. To account for practical deployment of LoRa gateways, we model the spatial distribution of the gateways with a Poisson point process (PPP) and Matèrn hard-core point process (MHC). Using our analytical formulation, we find the uplink performance in terms of success probability and potential throughput for each of the available SF in LoRa’s physical layer. Our results show that in dense multi-cell LoRa deployment with uplink traffic, the intercell interference noticeably degrades the system performance.
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| 3. |
- Beltramelli, Luca, et al.
(författare)
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Modeling of Enhanced Distributed Channel Access with Station Grouping: A Throughput Analysis
- 2018
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Ingår i: Proc. IEEE 88th Vehicular Technology Conference (VTC'18-fall), Chicago, USA, Aug. 2018.. - : IEEE conference proceedings.
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Konferensbidrag (refereegranskat)abstract
- Machine to Machine (M2M) communication networksare expected to connect a large number of power constrained devices in long range applications with differentquality of service (QoS) requirements. Medium access control with QoS support such as the Enhanced Distributed Channel Access (EDCA) defined by IEEE 802.11e provides traffic differentiation and corresponding priority classes, which guarantees QoSaccording to the needs of applications. In this paper, we employa station grouping mechanism for enhancing the scalability of EDCA to handle the massive number of access attempts expected in large M2M networks. Furthermore, we develop a discrete time Markov chain (DTMC) model to analyze the performance of EDCA with station grouping. Using the developed DTMC model, we calculate throughput for each access category as well as for different combinations of grouping and EDCA parameters. Thenumerical results show that the model can precisely reveal the behavior of EDCA mechanism. Moreover, it is demonstrated that employing the proposed grouping mechanism for EDCA increasesthe normalized throughput significantly for all classes of priority.
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| 4. |
- Beltramelli, Luca, et al.
(författare)
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Modelling of EnergyConsumption in IEEE 802.11.ah Networks for M2M Traffic
- 2016
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Ingår i: Proceedings of SNCNW 2016. ; , s. 38-41
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Konferensbidrag (refereegranskat)abstract
- IEEE 802.11ah is a sub-1 GHz standard designed to meet the requirements of future machine-to-machine (M2M) communications. The standard should be able to support use cases for the M2M communications with thousands of stations capable of generating both periodic and aperiodic traffic for a single access point. In some cases, like environmental and agricultural monitoring. the nodes are typically powered by battery or through energy harvesting. For this application it is important for the communication to be energy efficient. IEEE 802.11ah introduces new energy saving mechanisms and a novel channel access mechanism to achieve this objective even for networks with a large nodes number. This work proposes a mathematical model to compute the energy consumption of an IEEE 802.11ah network.
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| 5. |
- Butun, Ismail, et al.
(författare)
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Detecting Intrusions in Cyber-Physical Systems of Smart Cities : Challenges and Directions
- 2019
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Ingår i: Secure Cyber-Physical Systems for Smart Cities. - Hershey, USA : IGI Global. - 9781522571896 ; , s. 74-102
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Bokkapitel (refereegranskat)abstract
- Interfacing the smart cities with cyber-physical systems (CPSs) improves cyber infrastructures while introducing security vulnerabilities that may lead to severe problems such as system failure, privacy violation, and/or issues related to data integrity if security and privacy are not addressed properly. In order for the CPSs of smart cities to be designed with proactive intelligence against such vulnerabilities, anomaly detection approaches need to be employed. This chapter will provide a brief overview of the security vulnerabilities in CPSs of smart cities. Following a thorough discussion on the applicability of conventional anomaly detection schemes in CPSs of smart cities, possible adoption of distributed anomaly detection systems by CPSs of smart cities will be discussed along with a comprehensive survey of the state of the art. The chapter will discuss challenges in tailoring appropriate anomaly detection schemes for CPSs of smart cities and provide insights into future directions for the researchers working in this field.
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| 6. |
- Butun, Ismail, et al.
(författare)
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Preserving location privacy in cyber-physical systems
- 2019
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Ingår i: 2019 IEEE Conference on Communications and Network Security (CNS). - : IEEE. ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- The trending technological research platform is Internet of Things (IoT)and most probably it will stay that way for a while. One of the main application areas of IoT is Cyber-Physical Systems (CPSs), in which IoT devices can be leveraged as actuators and sensors in accordance with the system needs. The public acceptance and adoption of CPS services and applications will create a huge amount of privacy issues related to the processing, storage and disclosure of the user location information. As a remedy, our paper proposes a methodology to provide location privacy for the users of CPSs. Our proposal takes advantage of concepts such as mix-zone, context-awareness, and location-obfuscation. According to our best knowledge, the proposed methodology is the first privacy-preserving location service for CPSs that offers adaptable privacy levels related to the current context of the user.
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| 7. |
- Butun, Ismail, et al.
(författare)
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Security Implications of Fog Computing on the Internet of Things
- 2019
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Ingår i: International Conference on Consumer Electronics (ICCE). - : IEEE. - 9781538679104
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Konferensbidrag (refereegranskat)abstract
- Recently, the use of IoT devices and sensors has been rapidly increased which also caused data generation (information and logs), bandwidth usage, and related phenomena to be increased. To our best knowledge, a standard definition for the integration of fog computing with IoT is emerging now. This integration will bring many opportunities for the researchers, especially while building cyber-security related solutions. In this study, we surveyed about the integration of fog computing with IoT and its implications. Our goal was to find out and emphasize problems, specifically security related problems that arise with the employment of fog computing by IoT. According to our findings, although this integration seems to be non-trivial and complicated, it has more benefits than the implications. Index Terms—IoT, IIoT, vulnerabilities, trust, end-device, confidentiality, integrity, availability.
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| 8. |
- Farag, Hossam, et al.
(författare)
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A Delay-Bounded MAC Protocol for Mission- and Time-Critical Applications in Industrial Wireless Sensor Networks
- 2018
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 18:6, s. 2607-2616
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Tidskriftsartikel (refereegranskat)abstract
- Industrial Wireless Sensor Networks (IWSNs) designedfor mission- and time-critical applications require timelyand deterministic data delivery within stringent deadline bounds.Exceeding delay limits for such applications can lead to system malfunction or ultimately dangerous situations that can threaten human safety. In this paper, we propose SS-MAC, an efficient slot stealing MAC protocol to guarantee predictable and timely channel access for time-critical data in IWSNs. In the proposed SS-MAC, aperiodic time-critical traffic opportunistically steals time slots assigned to periodic non-critical traffic. Additionally, a dynamic deadline-based scheduling is introduced to provide guaranteed channel access in emergency and event-based situations where multiple sensor nodes are triggered simultaneously to transmit time-critical data to the controller. The proposed protocol is evaluated mathematically to provide the worst-case delay bound for the time-critical traffic. Performance comparisons are carried out between the proposed SS-MAC and WirelessHARTstandard and they show that, for the time-critical traffic, theproposed SS-MAC can achieve, at least, a reduction of almost 30% in the worst-case delay with a significant channel utilization efficiency.
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| 9. |
- Farag, Hossam, et al.
(författare)
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DeP-D : A Decentralized Primal-Dual Optimization Algorithm for Industrial Wireless Sensor Networks
- 2019
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Ingår i: 2019 15th IEEE International Workshop on Factory Communication Systems (WFCS). - : IEEE. - 9781728112688
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Konferensbidrag (refereegranskat)abstract
- Industrial Wireless Sensor Networks (IWSNs) are emerged as flexible and cost-efficient alternatives to the traditional wired networks in various monitoring and control applications within the industrial domain. Low delay is a key feature of delay-sensitive applications as the data is typically valid for a short interval of time. If data arrives too late it is of limited use which may lead to performance drops or even system outages which can create significant economical losses. In this paper, we propose a decentralized optimization algorithm to minimize the End-to-End (E2E) delay of multi-hop IWSNs. Firstly, we formulate the optimization problem by considering the objective function as the network delay where the constraint is the stability criteria based on the total arrival rate and the total service rate. The objective function is proved to be strictly convex for the entire network, then a Decentralized Primal-Dual (DeP-D) algorithm is proposed based on the sub-gradient method to solve the formulated optimization problem. The performance of the proposed DeP-D is evaluated through simulations and compared with WirelessHART network and the results show that the proposed DeP-D can achieve at least 40% reduction in the average E2E delay.
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| 10. |
- Farag, Hossam
(författare)
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Enabling Time- and Mission-Critical Applications in Industrial Wireless Sensor Networks
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nowadays, Wireless Sensor Networks (WSNs) have gained importance as aflexible, easier deployment/maintenance and cost-effective alternative to wired networks,e.g., Fieldbus and Wired-HART, in a wide-range of applications. Initially,WSNs were mostly designed for military and environmental monitoringapplications where energy efficiency is the main design goal. The nodes in the network were expected to have a long lifetime with minimum maintenance while providing best-effort data delivery which is acceptable in such scenarios. With recent advances in the industrial domain, WSNs have been subsequently extended to support industrial automation applications such as process automation and control scenarios. However, these emerging applications are characterized by stringent requirements regarding reliability and real-time communications that impose challenges in the design of Industrial Wireless Sensor Networks (IWSNs) to effectively support time- and mission-critical applications.Typically, time- and mission-critical applications support different traffic categories ranging from relaxed requirements, such as monitoring traffic to firm requirements, such as critical safety and emergency traffic. The critical traffic is mostly acyclic in nature and occasionally occurs at unpredictable time instants. Once it is generated, it must be delivered within strict deadlines. Exceeding the delay bound could lead to system instability, economic loss, or even endanger human life in the working area. The situation becomes even more challenging when an emergency event triggers multiple sensor nodes to transmit critical traffic to the controller simultaneously. The unpredictability of the arrival of such a type of traffic introduces difficulties with regard to making a suitable scheduling that guarantees data delivery within deadline bounds. Existing industrial standards and related research work have thus far not presented a satisfactory solution to the issue. Therefore, providing deterministic and timely delivery for critical traffic and its prioritization over regular traffic is a vital research topic.Motivated by the aforementioned challenges, this work aims to enable real-timecommunication for time- and mission-critical applications in IWSNs. In this context, improved Medium Access Control (MAC) protocols are proposed to enablea priority-based channel access that provides a timely delivery for acyclic critical traffic. The proposed framework starts with a stochastic modelling of the network delay performance under a priority-oriented transmission scheme, followed by two MAC approaches. The first approach proposes a random Clear Channel Assessment (CCA) mechanism to improve the transmission efficiency of acyclic control traffic that is generated occasionally as a result of observations of an established tendency, such as closed-loop supervisory traffic. A Discrete-Time Markov Chain (DTMC) model is provided to evaluate the performance of the proposed protocol analytically in terms of the expected delay and throughput. Numerical results show that the proposed random CCA mechanism improves the shared slots approach in WirelessHART in terms of delay and throughput along with better transmission reliability.The second approach introduces a slot-stealing MAC protocol based on a dynamic deadline-aware scheduling to provide deterministic channel access in emergency and event-based situations, where multiple sensor nodes are triggered simultaneously to transmit time-critical data to the controller. The proposed protocol is evaluated mathematically to provide the worst-case delay bound for the time-critical traffic and the numerical results show that the proposed approach outperforms TDMA-based WSNs in terms of delay and channel utilization.
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| 11. |
- Farag, Hossam, et al.
(författare)
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PR-CCA MAC : A Prioritized Random CCA MAC Protocol for Mission-Critical IoT Applications
- 2018
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Ingår i: 2018 IEEE International Conference on Communications (ICC). - : IEEE. - 9781538631805 - 9781538631812
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Konferensbidrag (refereegranskat)abstract
- A fundamental challenge in Mission-Critical Internetof Things (MC-IoT) is to provide reliable and timely deliveryof the unpredictable critical traffic. In this paper, we propose an efficient prioritized Medium Access Control (MAC) protocol for Wireless Sensor Networks (WSNs) in MC-IoT control applications. The proposed protocol utilizes a random Clear Channel Assessment (CCA)-based channel access mechanism to handlethe simultaneous transmissions of critical data and to reduce thecollision probability between the contending nodes, which in turn decreases the transmission latency. We develop a Discrete-Time Markov Chain (DTMC) model to evaluate the performance of the proposed protocol analytically in terms of the expected delay and throughput. The obtained results show that the proposed protocolcan enhance the performance of the WirelessHART standard by 80% and 190% in terms of latency and throughput, respectively along with better transmission reliability.
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| 12. |
- Farag, Hossam, et al.
(författare)
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Priority-Aware Wireless Fieldbus Protocol for Mixed-Criticality Industrial Wireless Sensor Networks
- 2019
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 19:7, s. 2767-2780
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Tidskriftsartikel (refereegranskat)abstract
- Industrial wireless sensor networks are becoming popular for critical monitoring and control applications in industrial automation systems. For such type of applications, providing reliable real-time performance regarding data delivery is considered as a fundamental challenge. The problem becomes more prominent with mixed-criticality systems, where different data flow with different levels of criticality (importance) coexist and characterized by different requirements regarding delay and reliability. In this paper, we propose a wireless fieldbus protocol to enable real-time communication and service differentiation for cluster-based mixed-criticality networks. A process monitoring scenario of plastic extrusion is used to define the protocol requirements and elaborate the working principle of the proposed work. In our proposed protocol, each data flow is scheduled for channel access based on its criticality level using a distributed prioritized medium access mechanism that ensures a guaranteed channel access for the most critical traffic over other traffic types. The performance of the proposed protocol is analyzed analytically using a discrete-time Markov chain model to evaluate the performance in terms of delay and throughput. Moreover, the extensive simulations are conducted to prove the analytical claims and different performance assessments are provided, which also demonstrate the effectiveness of the proposed approach compared with the related existing work.
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| 13. |
- Farag, Hossam, et al.
(författare)
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RMA-RP: A Reliable Mobility-Aware Routing Protocol for Industrial IoT Networks
- 2019
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Ingår i: 2019 IEEE Global Conference on Internet of Things (GCIoT). - : IEEE. - 9781728148731
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Konferensbidrag (refereegranskat)abstract
- Many emerging Industrial Internet of Things (IIoT) applications involve the use of mobile devices, such as sensors and robots in industrial automation scenarios. Movement of mobile sensor nodes causes intermittent connectivity which in turn deteriorates the network performance in terms of packet loss and delay. The Routing Protocol for Low Power and Lossy Networks (RPL) is introduced as the standard routing protocol for IIoT networks. Although RPL constitutes a reliable and energy-efficient solution for static networks, there is no mechanism defined in the RPL standard of how to support routing in mobile IIoT networks. This paper introduces RMA-RP, a reliable mobility-aware routing protocol to support mobile IIoT networks. RMA-RP utilizes a dynamic motion detection mechanism based on the link quality to cope with topology changes by updating next-hop nodes. Moreover, an adaptive timer is introduced to manage the transmission rate of control messages in order to decrease the network overhead and in turn the energy consumption. We evaluate the performance of RMA-RP through extensive simulations in comparison to existing works and the results demonstrate that RMA-RP has at least 17% higher packet delivery ratio and achieves a reduction of 34% and 51% in terms of delay and network overhead, respectively.
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| 14. |
- Forsström, Stefan, 1984-, et al.
(författare)
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Surveying and identifying the communication platforms of the internet of things
- 2018
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Ingår i: 2018 Global Internet of Things Summit, GIoTS 2018. - : IEEE. - 9781538664513
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Konferensbidrag (refereegranskat)abstract
- Research and industry invest time and resources in producing Internet of Things-based services, and the concept of Internet of Things platforms is climbing in the hype cycle for emerging technologies. Consequently, there is a vast number of enabling technologies, making it difficult to find the most suitable platform. The aim and goal of this article is to list and identify the currently available communication platforms for the Internet of Things. In this workwe surveyed the area and found over 128 different platforms for communication of data between things and services, out of which 42 fulfilled our listed basic requirements for being an IoT communication platform.
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