| 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. |
- Ferrari, Nico, et al.
(författare)
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Lightweight Group-Key Establishment Protocol for IoT Devices: Implementation and Performance Analyses
- 2018
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Ingår i: 2018 Fifth International Conference on Internet of Things. - : IEEE. - 9781538695852
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Konferensbidrag (refereegranskat)abstract
- In the context of Internet of Things (IoT), groupcommunication is an efficient and fast way of broadcastinggroup messages. The message needs to be sent securely tomaintain confidentiality of data and privacy of users. Estab-lishing cryptographically secure communication links betweena group of transceivers requires the pre-agreement upon somekey, unknown to an external attacker. Complex and resource-intensive security schemes are infeasible for devices with limitedcomputational capabilities. In this paper, we implement alightweight and computationally secure group key establish-ment scheme suitable for resource constrained IoT networks.The proposed scheme is based on elliptic curve cryptographyand cryptographic one-way accumulators. We analyze its fea-sibility by implementing it in the Contiki operating system andsimulating it with the Cooja simulator. The simulation resultsdemonstrate the feasibility of the scheme and its computationaland communication costs are also comparable with otherexisting approaches, with an energy consumption of only 109mJ per node for group key establishment.
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| 5. |
- Forsström, Stefan, 1984-, et al.
(författare)
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Challenges of Securing the Industrial Internet of Things Value Chain
- 2018
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Ingår i: 2018 Workshop on Metrology for Industry 4.0 and IoT, MetroInd 4.0 and IoT 2018 - Proceedings. - : IEEE. - 9781538624975 - 9781538624982 ; , s. 218-223
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Konferensbidrag (refereegranskat)abstract
- We see a shift from todays Internet-of-Things (IoT)to include more industrial equipment and metrology systems,forming the Industrial Internet of Things (IIoT). However, thisleads to many concerns related to confidentiality, integrity,availability, privacy and non-repudiation. Hence, there is a needto secure the IIoT in order to cater for a future with smart grids,smart metering, smart factories, smart cities, and smart manufacturing.It is therefore important to research IIoT technologiesand to create order in this chaos, especially when it comes tosecuring communication, resilient wireless networks, protectingindustrial data, and safely storing industrial intellectual propertyin cloud systems. This research therefore presents the challenges,needs, and requirements of industrial applications when it comesto securing IIoT systems.
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| 6. |
- Gebremichael, Teklay, 1985-
(författare)
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Lightweight Cryptographic Group Key Management Protocols for the Internet of Things
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Internet of Things (IoT) is increasingly becoming an integral component of many applications in consumer, industrial and other areas. Notions such as smart industry, smart transport, and smart world are, in large part, enabled by IoT. At its core, the IoT is underpinned by a group of devices, such as sensors and actuators, working collaboratively to provide a required service. One of the important requirements most IoT applications are expected to satisfy is ensuring the security and privacy of users. Security is an umbrella term that encompasses notions such as confidentiality, integrity and privacy, that are typically achieved using cryptographic encryption techniques.A special form of communication common in many IoT applications is group communication, where there are two or more recipients of a given message. In or-der to encrypt a message broadcast to a group, it is required that the participating parties agree on a group key a priori. Establishing and managing a group key in IoT environments, where devices are resources-constrained and groups are dynamic, is a non-trivial problem. The problem presents unique challenges with regard to con-structing protocols from lightweight and secure primitives commensurate with the resource-constrained nature of devices and maintaining security as devices dynamically leave or join a group.This thesis presents lightweight group key management protocols proposed to address the aforementioned problem, in a widely adopted model of a generic IoT network consisting of a gateway with reasonable computational power and a set of resource-constrained nodes. The aim of the group key management protocols is to enable the gateway and the set of resource-constrained devices to establish and manage a group key, which is then used to encrypt group messages. The main problems the protocols attempt to solve are establishing a group key among participating IoT devices in a secure and computationally feasible manner; enabling additionor removal of a device to the group in a security preserving manner; and enabling generation of a group session key in an efficient manner without re-running the protocol from scratch. The main challenge in designing such protocols is ensuring that the computations that a given IoT device performs as part of participating in the protocol are computationally feasible during initial group establishment, group keyupdate, and adding or removing a node from the group.The work presented in this thesis shows that the challenge can be overcome by designing protocols from lightweight cryptographic primitives. Specifically, protocols that exploit the lightweight nature of crypto-systems based on elliptic curves and the perfect secrecy of the One Time Pad (OTP) are presented. The protocols are designed in such a way that a resource-constrained member node performs a constant number of computationally easy computations during all stages of the group key management process.To demonstrate that the protocols are practically feasible, implementation resultof one of the protocols is also presented, showing that the protocol outperforms similar state-of-the-art protocols with regard to energy consumption, execution time, memory usage and number of messages generated.
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| 7. |
- Gebremichael, Teklay, 1985-, et al.
(författare)
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Lightweight IoT Group Key Establishment Scheme from the One Time Pad
- 2019
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Ingår i: 2019 7th IEEE International Conference on Mobile Cloud Computing, Services, and Engineering (MobileCloud). - : IEEE.
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Konferensbidrag (refereegranskat)abstract
- Secure group communication in the Internet ofThings (IoT) entails the establishment and management of one or more group keys to provide group security services such as confidentiality of group messages. The main challenges in establishing a group key consist in designing a group key establishment scheme that is feasible for nodes with limited computational capabilities. In this paper, we propose a lightweight group key establishment scheme based on fast symmetric-key encryption. We show a mechanism for designing a lightweight and secure IoT group key establishment and management scheme whose security is underpinned by the perfect secrecy provided by the One-time-pad. We then argue that the scheme is convenient for IoT group applications where nodes are resource-constrained. We prove that our scheme is secure under a threat model where the attacker has sufficiently large computational power. We also prove that the scheme provides desired group security properties such as confidentiality, key secrecy and independent group session keys generation.
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| 8. |
- Gebremichael, Teklay, 1985-, et al.
(författare)
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Lightweight IoT Group Key Establishment Scheme Using One-way Accumulator
- 2018
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Ingår i: 2018 International Symposium on Networks, Computers and Communications (ISNCC). - : IEEE. - 9781538637791
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Konferensbidrag (refereegranskat)abstract
- Group communication in the context of Internetof Things (IoT) is an efficient and fast way of broadcasting group messages. A message needs to be sent securely to maintain confidentiality of data and privacy of users. The main challenges in sharing group keys consist in designing and implementing a group key establishment scheme that is feasible for devices with limited computational capabilities. Existing group establishment schemes do not offer a good solution for resource-constrained IoTdevices, a solution that provides secure group key management procedures when new nodes join or leave the group without com-promising the security of the system. In this paper, we propose a light weight and computationally secure group key establishment scheme suitable for resource constrained IoT networks. The proposed scheme is based on elliptic curve cryptography and cryptographic one-way accumulators. We show how to combine the aforementioned concepts to design a group key establishment scheme that guarantees both forward and backward secrecy. Finally, we show how the established group key is updated when the group size dynamically changes and how the proposed solution can be used with block and stream ciphers.
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| 9. |
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| 10. |
- Lavassani, Mehrzad
(författare)
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Reliable Information Exchange in IIoT : Investigation into the Role of Data and Data-Driven Modelling
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The concept of Industrial Internet of Things (IIoT) is the tangible building block for the realisation of the fourth industrial revolution. It should improve productivity, efficiency and reliability of industrial automation systems, leading to revenue growth in industrial scenarios. IIoT needs to encompass various disciplines and technologies to constitute an operable and harmonious system. One essential requirement for a system to exhibit such behaviour is reliable exchange of information. In industrial automation, the information life-cycle starts at the field level, with data collected by sensors, and ends at the enterprise level, where that data is processed into knowledge for business decision making. In IIoT, the process of knowledge discovery is expected to start in the lower layers of the automation hierarchy, and to cover the data exchange between the connected smart objects to perform collaborative tasks.This thesis aims to assist the comprehension of the processes for information exchange in IIoT-enabled industrial automation- in particular, how reliable exchange of information can be performed by communication systems at field level given an underlying wireless sensor technology, and how data analytics can complement the processes of various levels of the automation hierarchy. Furthermore, this work explores how an IIoT monitoring system can be designed and developed.The communication reliability is addressed by proposing a redundancy-based medium access control protocol for mission-critical applications, and analysing its performance regarding real-time and deterministic delivery. The importance of the data and the benefits of data analytics for various levels of the automation hierarchy are examined by suggesting data-driven methods for visualisation, centralised system modelling and distributed data streams modelling. The design and development of an IIoT monitoring system are addressed by proposing a novel three-layer framework that incorporates wireless sensor, fog, and cloud technologies. Moreover, an IIoT testbed system is developed to realise the proposed framework.The outcome of this study suggests that redundancy-based mechanisms improve communication reliability. However, they can also introduce drawbacks, such as poor link utilisation and limited scalability, in the context of IIoT. Data-driven methods result in enhanced readability of visualisation, and reduced necessity of the ground truth in system modelling. The results illustrate that distributed modelling can lower the negative effect of the redundancy-based mechanisms on link utilisation, by reducing the up-link traffic. Mathematical analysis reveals that introducing fog layer in the IIoT framework removes the single point of failure and enhances scalability, while meeting the latency requirements of the monitoring application. Finally, the experiment results show that the IIoT testbed works adequately and can serve for the future development and deployment of IIoT applications.
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