@inproceedings{NsiahAlkhouriSikora, author = {Nsiah, Kofi Atta and Alkhouri, Kamil and Sikora, Axel}, title = {Configuration of Wireless TSN Networks}, series = {IEEE IDAACS-SWS 2020 : Conference Proceedings}, organization = {IEEE}, isbn = {978-1-7281-9960-3 (digital)}, doi = {10.1109/IDAACS-SWS50031.2020.9297066}, pages = {5}, language = {en} } @inproceedings{SikoraNyemkovaLakh, author = {Sikora, Axel and Nyemkova, Elena and Lakh, Yuriy}, title = {Accuracy Improvements of Identification and Authentication of Devices by EM-Measurements}, series = {IEEE IDAACS-SWS 2020 : Conference Proceedings}, organization = {IEEE}, isbn = {978-1-7281-9960-3 (digital)}, doi = {10.1109/IDAACS-SWS50031.2020.9297071}, pages = {5}, abstract = {The authentication method of electronic devices, based on individual forms of correlograms of their internal electric noises, is well-known. Specific physical differences in the components - for example, caused by variations in production quality - cause specific electrical signals, i.e. electric noise, in the electronic device. It is possible to obtain this information and to identify the specific differences of the individual devices using an embedded analog-to-digital converter (ADC). These investigations confirm the possibility to identify and authenticate electronic devices using bit templates, calculated from the sequence of values of the normalized autocorrelation function of noise. Experiments have been performed using personal computers. The probability of correct identification and authentication increases with increasing noise recording duration. As a result of these experiments, an accuracy of 98.1\% was achieved for a 1 second-long registration of EM for a set of investigated computers.}, language = {en} } @inproceedings{YusoffZakariaSikoraetal., author = {Yusoff, Nin Hayati Mohd and Zakaria, Nurul Azma and Sikora, Axel and Elayanithottathil, Jubin Sebastian}, title = {HRPL Protocol for 6LoWPAN Smart Home System: A Performance Assessment Analysis}, series = {IEEE IDAACS-SWS 2020 : Conference Proceedings}, organization = {IEEE}, isbn = {978-1-7281-9960-3 (digital)}, doi = {10.1109/IDAACS-SWS50031.2020.9297079}, pages = {5}, abstract = {The development of Internet of Things (IoT) embedded devices is proliferating, especially in the smart home automation system. However, the devices unfortunately are imposing overhead on the IoT network. Thus, the Internet Engineering Task Force (IETF) have introduced the IPv6 Low-Power Wireless Personal Area Network (6LoWPAN) to provide a solution to this constraint. 6LoWPAN is an Internet Protocol (IP) based communication where it allows each device to connect to the Internet directly. As a result, the power consumption is reduced. However, the limitation of data transmission frame size of the IPv6 Routing Protocol for Low-power and Lossy Network's (RPL's) had made it to be the running overhead, and thus consequently degrades the performance of the network in terms of Quality of Service (QoS), especially in a large network. Therefore, HRPL was developed to enhance the RPL protocol to minimize redundant retransmission that causes the routing overhead. We introduced the T-Cut Off Delay to set the limit of the delay and the H field to respond to actions taken within the T-Cut Off Delay. Thus, this paper presents the comparison performance assessment of HRPL between simulation and real-world scenarios (6LoWPAN Smart Home System (6LoSH) testbed) in validating the HRPL functionalities. Our results show that HRPL had successfully reduced the routing overhead when implemented in 6LoSH. The observed Control Traffic Overhead (CTO) packet difference between each experiment is 7.1\%, and the convergence time is 9.3\%. Further research is recommended to be conducted for these metrics: latency, Packet Delivery Ratio (PDR), and throughput.}, language = {en} } @inproceedings{LarionovLukashenkoMoschevikinetal., author = {Larionov, Dmitry and Lukashenko, Oleg and Moschevikin, Alex and Voronov, Roman and Sikora, Axel}, title = {Improving the Accuracy for Radio-Based Positioning in Mines Using SLAM}, series = {IEEE IDAACS-SWS 2020 : Conference Proceedings}, organization = {IEEE}, isbn = {978-1-7281-9960-3 (digital)}, doi = {10.1109/IDAACS-SWS50031.2020.9297088}, pages = {7}, abstract = {During the day-to-day exploitation of localization systems in mines, the technical staff tends to incorrectly rearrange radio equipment: positions of devices may not be accurately marked on a map or their positions may not correspond to the truth. This situation may lead to positioning inaccuracies and errors in the operation of the localization system.This paper presents two Bayesian algorithms for the automatic corrections of positions of the equipment on the map using trajectories restored by the inertial measurement units mounted to mobile objects, like pedestrians and vehicles. As a basis, a predefined map of the mine represented as undirected weighted graph was used as input. The algorithms were implemented using the Simultaneous Localization and Mapping (SLAM) approach.The results prove that both methods are capable to detect misplacement of access points and to provide corresponding corrections. The discrete Bayesian filter outperforms the unscented Kalman filter, which, however, requires more computational power.}, language = {en} } @inproceedings{ČečilŠetkaTolaretal., author = {Čečil, Roman and Šetka, Vlastimil and Tolar, David and Sikora, Axel}, title = {RETIS - Real-Time Sensitive Wireless Communication Solution for Industrial Control Applications}, series = {IEEE IDAACS-SWS 2020 : Conference Proceedings}, organization = {IEEE}, isbn = {978-1-7281-9960-3 (digital)}, doi = {10.1109/IDAACS-SWS50031.2020.9297074}, pages = {9}, abstract = {Ultra-Reliable Low Latency Communications (URLLC) has been always a vital component of many industrial applications. The paper proposes a new wireless URLLC solution called RETIS, which is suitable for factory automation and fast process control applications, where low latency, low jitter, and high data exchange rates are mandatory. In the paper, we describe the communication protocol as well as the hardware structure of the network nodes for implementing the required functionality. Many techniques enabling fast, reliable wireless transmissions are used - short Transmission Time Interval (TTI), Time-Division Multiple Access (TDMA), MIMO, optional duplicated data transfer, Forward Error Correction (FEC), ACK mechanism. Preliminary tests show that reliable end-to-end latency down to 350 μs and packet exchange rate up to 4 kHz can be reached (using quadruple MIMO and standard IEEE 802.15.4 PHY at 250 kbit/s).}, language = {en} } @inproceedings{AbdolinezhadSchappacherSikora, author = {Abdolinezhad, Saeed and Schappacher, Manuel and Sikora, Axel}, title = {Secure Wireless Architecture for Communications in a Parcel Delivery System}, series = {IEEE IDAACS-SWS 2020 : Conference Proceedings}, organization = {IEEE}, isbn = {978-1-7281-9960-3 (digital)}, doi = {10.1109/IDAACS-SWS50031.2020.9297086}, pages = {6}, abstract = {The number of use cases for autonomous vehicles is increasing day by day especially in commercial applications. One important application of autonomous vehicles can be found within the parcel delivery section. Here, autonomous cars can massively help to reduce delivery efforts and time by supporting the courier actively. One important component of course is the autonomous vehicle itself. Nevertheless, beside the autonomous vehicle, a flexible and secure communication architecture also is a crucial key component impacting the overall performance of such system since it is required to allow continuous interactions between the vehicle and the other components of the system. The communication system must provide a reliable and secure architecture that is still flexible enough to remain practical and to address several use cases. In this paper, a robust communication architecture for such autonomous fleet-based systems is proposed. The architecture provides a reliable communication between different system entities while keeping those communications secure. The architecture uses different technologies such as Bluetooth Low Energy (BLE), cellular networks and Low Power Wide Area Network (LPWAN) to achieve its goals.}, language = {en} } @inproceedings{RomanovVolkovaSikora, author = {Romanov, Alexey M. and Volkova, Maria A. and Sikora, Axel}, title = {A Novel Low-Jitter Interface for Synchronization with Low-Cost Integrated IEEE802.11 Chips}, series = {2020 Systems of Signal Synchronization, Generating and Processing in Telecommunications (SYNCHROINFO)}, organization = {IEEE}, isbn = {978-1-7281-6072-6 (digital)}, doi = {10.1109/SYNCHROINFO49631.2020.9166100}, pages = {6}, abstract = {This paper presents a novel low-jitter interface between a low-cost integrated IEEE802.11 chip and a FPGA. It is designed to be part of system hardware for ultra-precise synchronization between wireless stations. On physical level, it uses Wi-Fi chip coexistence signal lines and UART frame encoding. On its basis, we propose an efficient communication protocol providing precise timestamping of incoming frames and internal diagnostic mechanisms for detecting communication faults. Meanwhile it is simple enough to be implemented both in low-cost FPGA and commodity IEEE802.11 chip firmware. The results of computer simulation shows that developed FPGA implementation of the proposed protocol can precisely timestamp incoming frames as well as detect most of communication errors even in conditions of high interference. The probability of undetected errors was investigated. The results of this analysis are significant for the development of novel wireless synchronization hardware.}, language = {en} } @inproceedings{SikoraWalzZimmermann, author = {Sikora, Axel and Walz, Andreas and Zimmermann, Lukas}, title = {Research Aspects for Secure Communication in the Industrial Internet of Things}, series = {Proceedings: 2020 IEEE 11th International Conference on Dependable Systems, Services and Technologies (DESSERT)}, organization = {IEEE}, isbn = {978-1-7281-9957-3 (digital)}, doi = {10.1109/DESSERT50317.2020.9125002}, pages = {284 -- 289}, abstract = {With the increasing degree of interconnectivity in industrial factories, security becomes more and more the most important stepping-stone towards wide adoption of the Industrial Internet of Things (IIoT). This paper summarizes the most important aspects of one keynote of DESSERT2020 conference. It highlights the ongoing and open research activities on the different levels, from novel cryptographic algorithms over security protocol integration and testing to security architectures for the full lifetime of devices and systems. It includes an overview of the research activities at the authors' institute.}, language = {en} } @inproceedings{AlkhouriSikoraNeheretal., author = {Alkhouri, Kamil and Sikora, Axel and Neher, Philipp and Frick, Frick}, title = {Time Synchronization for Time Sensitive Networks}, series = {Proceedings of the embedded world Conference 2020}, publisher = {WEKA Fachmedien}, isbn = {978-3-645-50186-6}, pages = {79 -- 84}, language = {en} } @inproceedings{MattSchappacherSikora, author = {Matt, Thomas and Schappacher, Manuel and Sikora, Axel}, title = {A Web-Based Monitoring Tool for Metering Bus (EN13757-3)}, series = {Tagungsband zum Workshop der Multiprojekt-Chip-Gruppe Baden-W{\"u}rttemberg, Ulm, Juli 2015}, volume = {54}, organization = {Hochschule Ulm}, issn = {1868-9221}, pages = {97 -- 104}, abstract = {The Metering Bus, also known as M-Bus, is a European standard EN13757-3 for reading out metering devices, like electricity, water, gas, or heat meters. Although real-life M-Bus networks can reach a significant size and complexity, only very simple protocol analyzers are available to observe and maintain such networks. In order to provide developers and installers with the ability to analyze the real bus signals easily, a web-based monitoring tool for the M-Bus has been designed and implemented. Combined with a physical bus interface it allows for measuring and recording the bus signals. For this at first a circuit has been developed, which transforms the voltage and current-modulated M-Bus signals to a voltage signal that can be read by a standard ADC and processed by an MCU. The bus signals and packets are displayed using a web server, which analyzes and classifies the frame fragments. As an additional feature an oscilloscope functionality is included in order to visualize the physical signal on the bus. This paper describes the development of the read-out circuit for the Wired M-Bus and the data recovery.}, language = {en} } @inproceedings{ZimmermannScholzTahoorietal., author = {Zimmermann, Lukas and Scholz, Alexander and Tahoori, Mehdi Baradaran and Sikora, Axel and Aghassi-Hagmann, Jasmin}, title = {Hardware-Intrinsic Security with Printed Electronics for Identification of IoE Devices}, series = {2020 European Conference on Circuit Theory and Design (ECCTD) : Proceedings}, organization = {IEEE}, isbn = {978-1-7281-7183-8 (eBook)}, issn = {2474-9672 (Online)}, doi = {10.1109/ECCTD49232.2020.9218277}, pages = {4}, abstract = {Novel manufacturing technologies, such as printed electronics, may enable future applications for the Internet of Everything like large-area sensor devices, disposable security, and identification tags. Printed physically unclonable functions (PUFs) are promising candidates to be embedded as hardware security keys into lightweight identification devices. We investigate hybrid PUFs based on a printed PUF core. The statistics on the intra- and inter-hamming distance distributions indicate a performance suitable for identification purposes. Our evaluations are based on statistical simulations of the PUF core circuit and the thereof generated challenge-response pairs. The analysis shows that hardware-intrinsic security features can be realized with printed lightweight devices.}, language = {en} } @inproceedings{ElayanithottathilSikoraSchappacheretal., author = {Elayanithottathil, Jubin Sebastian and Sikora, Axel and Schappacher, Manuel and Amjad, Zubair}, title = {Test and Measurement of LPWAN and Cellular IoT Networks in a Unified Testbed}, series = {2019 IEEE 17th International Conference on Industrial Informatics (INDIN) : Proceedings}, organization = {IEEE}, isbn = {978-1-7281-2927-3}, issn = {2378-363X}, doi = {10.1109/INDIN41052.2019.8972256}, pages = {1521 -- 1527}, language = {en} } @inproceedings{ElayanithottathilSikora, author = {Elayanithottathil, Jubin Sebastian and Sikora, Axel}, title = {Advances in the Automated Test and Measurement Infrastructure of Narrowband Wireless WAN}, series = {International Conference on Intelligent Computing, Instrumentation and Control Technologies (ICICICT)5. \& 6. july 2019 Kannur, Kerala, India}, organization = {Institute of Electrical and Electronics Engineers}, isbn = {978-1-72810-283-2}, doi = {10.1109/ICICICT46008.2019.8993127}, pages = {1571 -- 1577}, language = {en} } @inproceedings{RomanovGringoliSikora, author = {Romanov, Alexey M. and Gringoli, Francesco and Sikora, Axel}, title = {High Precision Synchronization between Commercial WiFi-ICs and External Device}, series = {Proceedings of the 16th IEEE Workshop on Positioning, Navigation and Communications (WPNC), Bremen, Germany, Oct. 23-24, 2019}, organization = {IEEE}, isbn = {978-1-7281-2082-9 (digital)}, issn = {2164-9758}, doi = {10.1109/WPNC47567.2019.8970260}, pages = {6}, abstract = {Wireless synchronization of industrial controllers is a challenging task in environments where wired solutions are not practical. The best solutions proposed so far to solve this problem require pretty expensive and highly specialized FPGA-based devices. With this work we counter the trend by introducing a straightforward approach to synchronize a fairly cheap IEEE 802.11 integrated wireless chip (IWC) with external devices. More specifically we demonstrate how we can reprogram the software running in the 802.11 IWC of the Raspberry Pi 3B and transform the receiver input potential of the wireless transceiver into a triggering signal for an external inexpensive FPGA. Experimental results show a mean-square synchronization error of less than 496 ns, while the absolute synchronization error does not exceed 6 μs. The jitter of the output signal that we obtain after synchronizing the clock of the external device did not exceed 5.2 μs throughout the whole measurement campaign. Even though we do not score new records in term of accuracy, we do in terms of complexity, cost, and availability of the required components: all these factors make the proposed technique a very promising of the deployment of large-scale low-cost automation solutions.}, language = {en} } @inproceedings{AhmadPashaSchappacheretal., author = {Ahmad, Afzal and Pasha, Muhammad Adeel and Schappacher, Manuel and Belhouichet, Assila and Masud, Shahid and Sikora, Axel}, title = {Multi-hop Routing Implementation in Spatially Distributed Wireless Sensor Networks for Large-Scale Environmental Monitoring Applications}, series = {Proceedings of the 2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, organization = {IEEE}, isbn = {978-1-7281-4069-8 (digital)}, doi = {10.1109/IDAACS.2019.8924282}, pages = {111 -- 116}, abstract = {With the surge in global data consumption with proliferation of Internet of Things (IoT), remote monitoring and control is increasingly becoming popular with a wide range of applications from emergency response in remote regions to monitoring of environmental parameters. Mesh networks are being employed to alleviate a number of issues associated with single-hop communication such as low area coverage, reliability, range and high energy consumption. Low-power Wireless Personal Area Networks (LoWPANs) are being used to help realize and permeate the applicability of IoT. In this paper, we present the design and test of IEEE 802.15.4-compliant smart IoT nodes with multi-hop routing. We first discuss the features of the software stack and design choices in hardware that resulted in high RF output power and then present field test results of different baseline network topologies in both rural and urban settings to demonstrate the deployability and scalability of our solution.}, language = {en} } @inproceedings{NsiahAmjadSikoraetal., author = {Nsiah, Kofi Atta and Amjad, Zubair and Sikora, Axel and Hilt, Beno{\^i}t and Lauffenburger, Jean-Philippe}, title = {Latency Reduction Techniques for NB-IoT Networks}, series = {Proceedings of the 2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, organization = {IEEE}, isbn = {978-1-7281-4069-8 (digital)}, doi = {10.1109/IDAACS.2019.8924238}, pages = {478 -- 483}, abstract = {Enabling ultra-low latency is one of the major drivers for the development of future cellular networks to support delay sensitive applications including factory automation, autonomous vehicles and tactile internet. Narrowband Internet of Things (NB-IoT) is a 3 rd Generation Partnership Project (3GPP) Release 13 standardized cellular network currently optimized for massive Machine Type Communication (mMTC). To reduce the latency in cellular networks, 3GPP has proposed some latency reduction techniques that include Semi Persistent Scheduling (SPS) and short Transmission Time Interval (sTTI). In this paper, we investigate the potential of adopting both techniques in NB-IoT networks and provide a comprehensive performance evaluation. We firstly analyze these techniques and then implement them in an open-source network simulator (NS3). Simulations are performed with a focus on Cat-NB1 User Equipment (UE) category to evaluate the uplink user-plane latency. Our results show that SPS and sTTI have the potential to greatly reduce the latency in NB-IoT systems. We believe that both techniques can be integrated into NB-IoT systems to position NB-IoT as a preferred technology for low data rate Ultra-Reliable Low-Latency Communication (URLLC) applications before 5G has been fully rolled out.}, language = {en} } @inproceedings{KallelUzielSchappacheretal., author = {Kallel, Ahmed Yahia and Uziel, Sebastian and Schappacher, Manuel and Sikora, Axel and Keutel, Thomas and Kanoun, Olfa}, title = {A Cost-Efficient and Continuous Ethernet Cable Diagnosis Technique based on Undersampling}, series = {Proceedings of the 2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, address = {Metz}, organization = {IEEE}, isbn = {978-1-7281-4069-8 (digital)}, doi = {10.1109/IDAACS.2019.8924458}, pages = {695 -- 700}, abstract = {The monitoring of industrial environments ensures that highly automated processes run without interruption. However, even if the industrial machines themselves are monitored, the communication lines are currently not continuously monitored in todays installations. They are checked usually only during maintenance intervals or in case of error. In addition, the cables or connected machines usually have to be removed from the system for the duration of the test. To overcome these drawbacks, we have developed and implemented a cost-efficient and continuous signal monitoring of Ethernet-based industrial bus systems. Several methods have been developed to assess the quality of the cable. These methods can be classified to either passive or active. Active methods are not suitable if interruption of the communication is undesired. Passive methods, on the other hand, require oversampling, which calls for expensive hardware. In this paper, a novel passive method combined with undersampling targeting cost-efficient hardware is proposed.}, language = {en} } @inproceedings{ElayanithottathilSikora, author = {Elayanithottathil, Jubin Sebastian and Sikora, Axel}, title = {Performance Measurements of Narrowband-IoT Network in Emulated and Field Testbeds}, series = {Proceedings of the 2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, organization = {IEEE}, isbn = {978-1-7281-4069-8 (digital)}, doi = {10.1109/IDAACS.2019.8924357}, pages = {780 -- 785}, abstract = {Narrowband IoT (NB-IoT) as a radio access technology for the cellular Internet of Things (cIoT) is getting more traction due to attractive system parameters, new proposals in the 3 rd Generation Partnership Project (3GPP) Release 14 for reduced power consumption and ongoing world-wide deployment. As per 3GPP, the low-power and wide-area use cases in 5G specification will be addressed by the early NB-IoT and Long-Term Evolution for Machines (LTE-M) based technologies. Since these cIoT networks will operate in a spatially distributed environment, there are various challenges to be addressed for tests and measurements of these networks. To meet these requirements, unified emulated and field testbeds for NB-IoT-networks were developed and used for extensive performance measurements. This paper analyses the results of these measurements with regard to RF coverage, signal quality, latency, and protocol consistency.}, language = {en} } @inproceedings{VoronovMoschevikinSikora, author = {Voronov, Roman and Moschevikin, Alex and Sikora, Axel}, title = {A Method for Optimum Placement of Access Points in Indoor Positioning Systems}, series = {Proceedings of the 2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, organization = {IEEE}, isbn = {978-1-7281-4069-8 (digital)}, doi = {10.1109/IDAACS.2019.8924405}, pages = {1130 -- 1135}, abstract = {When designing and installing Indoor Positioning Systems, several interrelated tasks have to be solved to find an optimum placement of the Access Points. For this purpose, a mathematical model for a predefined number of access points indoors is presented. Two iterative algorithms for the minimization of localization error of a mobile object are described. Both algorithms use local search technique and signal level probabilities. Previously registered signal strengths maps were used in computer simulation.}, language = {en} } @inproceedings{StodtJastremskojReichetal., author = {Stodt, Jan and Jastremskoj, Eugen and Reich, Christoph and Welte, Dominik and Sikora, Axel}, title = {Formal Description of Use Cases for Industry 4.0 Maintenance Processes Using Blockchain Technology}, series = {Proceedings of the 2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, organization = {IEEE}, isbn = {978-1-7281-4069-8 (digital)}, doi = {10.1109/IDAACS.2019.8924382}, pages = {1136 -- 1141}, abstract = {Maintenance processes in Industry 4.0 applications try to achieve a high degree of quality to reduce the downtime of machinery. The monitoring of executed maintenance activities is challenging as in complex production setups, multiple stakeholders are involved. So, full transparency of the different activities and of the state of the machine can only be supported, if these stakeholders trust each other. Therefore, distributed ledger technologies, like Blockchain, can be promising candidates for supporting such applications. The goal of this paper is a formal description of business and technical interactions between non-trustful stakeholders in the context of Industry 4.0 maintenance processes using distributed ledger technologies. It also covers the integration of smart contracts for automated triggering of activities.}, language = {en} } @inproceedings{YusoffZakariaSikoraetal., author = {Yusoff, Nin Hayati Mohd and Zakaria, Nurul Azma and Sikora, Axel and Elayanithottathil, Jubin Sebastian}, title = {6LoWPAN Protocol in Fixed Environment: A Performance Assessment Analysis}, series = {Proceedings of the 2019 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, volume = {2}, organization = {IEEE}, isbn = {978-1-7281-4069-8 (digital)}, doi = {10.1109/IDAACS.2019.8924283}, pages = {1142 -- 1147}, abstract = {The Internet of Things (IoT) application has becoming progressively in-demand, most notably for the embedded devices (ED). However, each device has its own difference in computational capabilities, memory usage, and energy resources in connecting to the Internet by using Wireless Sensor Networks (WSNs). In order for this to be achievable, the WSNs that form the bulk of the IoT implementation requires a new set of technologies and protocol that would have a defined area, in which it addresses. Thus, IPv6 Low Power Area Network (6LoWPAN) was designed by the Internet Engineering Task Force (IETF) as a standard network for ED. Nevertheless, the communication between ED and 6LoWPAN requires appropriate routing protocols for it to achieve the efficient Quality of Service (QoS). Among the protocols of 6LoWPAN network, RPL is considered to be the best protocol, however its Energy Consumption (EC) and Routing Overhead (RO) is considerably high when it is implemented in a large network. Therefore, this paper would propose the HRPL to enchance the RPL protocol in reducing the EC and RO. In this study, the researchers would present the performance of RPL and HRPL in terms of EC, Control traffic Overhead (CTO) and latency based on the simulation of the 6LoWPAN network in fixed environment using COOJA simulator. The results show HRPL protocol achieves better performance in all the tested topology in terms of EC and CTO. However, the latency of HRPL only improves in chain topology compared with RPL. We found that further research is required to study the relationship between the latency and the load of packet transmission in order to optimize the EC usage.}, language = {en} } @inproceedings{ElayanithottathilSchappacherSikora, author = {Elayanithottathil, Jubin Sebastian and Schappacher, Manuel and Sikora, Axel}, title = {Unified Test Environment for LPWAN and Cellular IoT}, series = {Proceedings of embedded world Conference 2019, Nuremberg, Germany, 26.-28.02.2019}, publisher = {WEKA FACHMEDIEN GmbH}, address = {Haar}, pages = {187 -- 191}, language = {en} } @inproceedings{NsiahAmjadSikora, author = {Nsiah, Kofi Atta and Amjad, Zubair and Sikora, Axel}, title = {Performance Evaluation of Ultra-Low Latency Wireless Communication in Industrial Automation}, series = {Proceedings of embedded world Conference 2019, Nuremberg, Germany, 26.-28.02.2019}, publisher = {WEKA FACHMEDIEN GmbH}, address = {Haar}, pages = {174 -- 179}, language = {en} } @inproceedings{NsiahAmjadSikoraetal., author = {Nsiah, Kofi Atta and Amjad, Zubair and Sikora, Axel and Hilt, Beno{\^i}t}, title = {Performance Evaluation of Latency for NB-LTE Networks in Industrial Automation}, series = {2019 IEEE 30th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) 8-11 Sept. 2019 Istanbul, Turkey}, publisher = {IEEE}, isbn = {978-1-5386-8111-4}, doi = {10.1109/PIMRC.2019.8904407}, pages = {1 -- 7}, language = {en} } @inproceedings{SikoraKang, author = {Sikora, Axel and Kang, Jason Z.}, title = {Message from the conference chair ICSGCE 2015}, series = {2015 International Conference on Smart Grid and Clean Energy Technologies (ICSGCE)}, volume = {2015}, organization = {IEEE}, isbn = {978-1-4673-8732-3}, doi = {10.1109/ICSGCE.2015.7454258}, pages = {vii -- viii}, abstract = {Energy and environment continue to be major issues of human mankind. This holds true on the regional, the national, and the global level. And it is one of the problems, where engineers and scientists in conjunction with political will and people's awareness, can find new approaches and solutions to save the natural resources and to make their use more efficient.}, language = {en} } @inproceedings{MoschevikinSikora, author = {Moschevikin, Alex and Sikora, Axel}, title = {ОПЫТ ИСПОЛЬЗОВАНИЯ ГРАНТОВ DAAD ДЛЯ РАЗВИТИЯ БИЗНЕСА, НАУКИ И ОБРАЗОВАНИЯ}, series = {Цифровые технологии в образовании, науке, обществе : материалы конференции, Петрозаводск, 4-6 декабря 2018}, booktitle = {Experience of using DAAD grants for business development, science and education}, address = {Petrozavodsk}, isbn = {978-5-8021-3418-4}, pages = {172 -- 175}, language = {ru} } @inproceedings{YushevBarghashNguyenetal., author = {Yushev, Artem and Barghash, Mohammed and Nguyen, Minh Phuong and Walz, Andreas and Sikora, Axel}, title = {TLS-over-CAN: An Experimental Study of Internet-Grade End-to-End Communication Security for CAN Networks}, series = {IFAC-PapersOnLine}, volume = {51}, number = {6}, editor = {Slanina, Zdenek}, publisher = {Elsevier}, address = {Frankfurt und M{\"u}nchen [u.a.]}, issn = {2405-8963}, doi = {10.1016/j.ifacol.2018.07.136}, pages = {96 -- 101}, abstract = {The CAN bus still is an important fieldbus in various domains, e.g. for in-car communication or automation applications. To counter security threats and concerns in such scenarios we design, implement, and evaluate the use of an end-to-end security concept based on the Transport Layer Security protocol. It is used to establish authenticated, integrity-checked, and confidential communication channels between field devices connected via CAN. Our performance measurements show that it is possible to use TLS at least for non time-critical applications, as well as for generic embedded networks.}, language = {en} } @inproceedings{ZimmermannScholzSikoraetal., author = {Zimmermann, Lukas and Scholz, Alexander and Sikora, Axel and Aghassi-Hagmann, Jasmin}, title = {A Hybrid System Architecture for the Readout of a Printed Physical Unclonable Function}, series = {Conference Proceedings of 2018 International Conference on Electronics Technology}, address = {Piscataway}, isbn = {978-1-5386-5752-2 (digital)}, doi = {10.1109/ELTECH.2018.8401395}, pages = {11 -- 14}, abstract = {Uncontrollable manufacturing variations in electrical hardware circuits can be exploited as Physical Unclonable Functions (PUFs). Herein, we present a Printed Electronics (PE)-based PUF system architecture. Our proposed Differential Circuit PUF (DiffC-PUF) is a hybrid system, combining silicon-based and PE-based electronic circuits. The novel approach of the DiffC-PUF architecture is to provide a specially designed real hardware system architecture, that enables the automatic readout of interchangeable printed DiffC-PUF core circuits. The silicon-based addressing and evaluation circuit supplies and controls the printed PUF core and ensures seamless integration into silicon-based smart systems. Major objectives of our work are interconnected applications for the Internet of Things (IoT).}, language = {en} } @inproceedings{AmjadSikoraHiltetal., author = {Amjad, Zubair and Sikora, Axel and Hilt, Benoit and Lauffenburger, Jean-Philippe}, title = {Low Latency V2X Applications and Network Requirements: Performance Evaluation}, series = {2018 IEEE Intelligent Vehicles Symposium (IV), 26-30 June 2018, Changshu, China}, isbn = {978-1-5386-4452-2 (digital)}, issn = {1931-0587}, doi = {10.1109/IVS.2018.8500531}, pages = {220 -- 225}, abstract = {Vehicle-to-Everything (V2X) communication promises improvements in road safety and efficiency by enabling low-latency and reliable communication services for vehicles. Besides using Mobile Broadband (MBB), there is a need to develop Ultra Reliable Low Latency Communications (URLLC) applications with cellular networks especially when safety-related driving applications are concerned. Future cellular networks are expected to support novel latencysensitive use cases. Many applications of V2X communication, like collaborative autonomous driving requires very low latency and high reliability in order to support real-time communication between vehicles and other network elements. In this paper, we classify V2X use-cases and their requirements in order to identify cellular network technologies able to support them. The bottleneck problem of the medium access in 4G Long Term Evolution(LTE) networks is random access procedure. It is evaluated through simulations to further detail the future limitations and requirements. Limitations and improvement possibilities for next generation of cellular networks are finally detailed. Moreover, the results presented in this paper provide the limits of different parameter sets with regard to the requirements of V2X-based applications. In doing this, a starting point to migrate to Narrowband IoT (NB-IoT) or 5G - solutions is given.}, language = {en} } @inproceedings{AmjadSikoraLauffenburger, author = {Amjad, Zubair and Sikora, Axel and Lauffenburger, Jean-Philippe}, title = {Latency Reduction in Narrowband 4G LTE Networks}, series = {Proceedings of the 15th International IEEE Symposium on Wireless Communication Systems (ISWCS), 28-31 August 2018, Lisbon, Portugal}, isbn = {978-1-5386-5005-9 (digital)}, issn = {2154-0225 (digital)}, doi = {10.1109/ISWCS.2018.8491085}, pages = {5}, abstract = {The next generation cellular networks are expected to improve reliability, energy efficiency, data rate, capacity and latency. Originally, Machine Type Communication (MTC) was designed for low-bandwidth high-latency applications such as, environmental sensing, smart dustbin, etc., but there is additional demand around applications with low latency requirements, like industrial automation, driver-less cars, and so on. Improvements are required in 4G Long Term Evolution (LTE) networks towards the development of next generation cellular networks for providing very low latency and high reliability. To this end, we present an in-depth analysis of parameters that contribute to the latency in 4G networks along with a description of latency reduction techniques. We implement and validate these latency reduction techniques in the open-source network simulator (NS3) for narrowband user equipment category Cat-Ml (LTE-M) to analyze the improvements. The results presented are a step towards enabling narrowband Ultra Reliable Low Latency Communication (URLLC) networks.}, language = {en} } @inproceedings{AmjadSikoraHiltetal., author = {Amjad, Zubair and Sikora, Axel and Hilt, Benoit and Lauffenburger, Jean-Philippe}, title = {Latency Reduction for Narrowband LTE with Semi-Persistent Scheduling}, series = {Proceedings of the 4th IEEE International Symposium on Wireless Systems within the International Conferences on Intelligent Data Acquisition and Advanced Computing Systems (IDAACS-SWS), 20-21 September 2018, Lviv, Ukraine}, isbn = {978-1-5386-7587-8 (digital)}, doi = {10.1109/IDAACS-SWS.2018.8525713}, pages = {196 -- 198}, abstract = {The excessive control signaling in Long Term Evolution networks required for dynamic scheduling impedes the deployment of ultra-reliable low latency applications. Semi-persistent scheduling was originally designed for constant bit-rate voice applications, however, very low control overhead makes it a potential latency reduction technique in Long Term Evolution. In this paper, we investigate resource scheduling in narrowband fourth generation Long Term Evolution networks through Network Simulator (NS3) simulations. The current release of NS3 does not include a semi-persistent scheduler for Long Term Evolution module. Therefore, we developed the semi-persistent scheduling feature in NS3 to evaluate and compare the performance in terms of uplink latency. We evaluate dynamic scheduling and semi-persistent scheduling in order to analyze the impact of resource scheduling methods on up-link latency.}, language = {en} } @inproceedings{WalzHarrisSikora, author = {Walz, Andreas and Harris, Muhammad and Sikora, Axel}, title = {Investigating and Optimising the DTLS Handshake over Wireless Links with High Error Rate and Low Data Rate}, series = {Proceedings of the 4th IEEE International Symposium on Wireless Systems within the International Conferences on Intelligent Data Acquisition and Advanced Computing Systems (IDAACS-SWS), 20-21 September 2018, Lviv, Ukraine}, isbn = {978-1-5386-7587-8 (digital)}, doi = {10.1109/IDAACS-SWS.2018.8525798}, pages = {175 -- 178}, abstract = {The Datagram Transport Layer Security (DTLS) protocol has been designed to provide end-to-end security over unreliable communication links. Where its connection establishment is concerned, DTLS copes with potential loss of protocol messages by implementing its own loss detection and retransmission scheme. However, the default scheme turns out to be suboptimal for links with high transmission error rates and low data rates, such as wireless links in electromagnetically harsh industrial environments. Therefore, in this paper, as a first step we provide an analysis of the standard DTLS handshake's performance under such adverse transmission conditions. Our studies are based on simulations that model message loss as the result of bit transmission errors. We consider several handshake variants, including endpoint authentication via pre-shared keys or certificates. As a second step, we propose and evaluate modifications to the way message loss is dealt with during the handshake, making DTLS deployable in situations which are prohibitive for default DTLS.}, language = {en} } @inproceedings{WalzSikora, author = {Walz, Andreas and Sikora, Axel}, title = {Maximizing and Leveraging Behavioral Discrepancies in TLS Implementations using Response-Guided Differential Fuzzing}, series = {Proceedings of the 52nd IEEE International Carnahan Conference on Security Technology (ICCST 2018), 22-25 October 2018, Montr{\´e}al, Canada}, isbn = {978-1-5386-7931-9 (digital)}, issn = {2153-0742 (digital)}, doi = {10.1109/CCST.2018.8585565}, pages = {5}, abstract = {The Transport Layer Security (TLS) protocol is a cornerstone of secure network communication, not only for online banking, e-commerce, and social media, but also for industrial communication and cyber-physical systems. Unfortunately, implementing TLS correctly is very challenging, as becomes evident by considering the high frequency of bugfixes filed for many TLS implementations. Given the high significance of TLS, advancing the quality of implementations is a sustained pursuit. We strive to support these efforts by presenting a novel, response-distribution guided fuzzing algorithm for differential testing of black-box TLS implementations. Our algorithm generates highly diverse and mostly-valid TLS stimulation messages, which evoke more behavioral discrepancies in TLS server implementations than other algorithms. We evaluate our algorithm using 37 different TLS implementations and discuss―by means of a case study―how the resulting data allows to assess and improve not only implementations of TLS but also to identify underspecified corner cases. We introduce suspiciousness as a per-implementation metric of anomalous implementation behavior and find that more recent or bug-fixed implementations tend to have a lower suspiciousness score. Our contribution is complementary to existing tools and approaches in the area, and can help reveal implementation flaws and avoid regression. While being presented for TLS, we expect our algorithm's guidance scheme to be applicable and useful also in other contexts. Source code and data is made available for fellow researchers in order to stimulate discussions and invite others to benefit from and advance our work.}, language = {en} } @inproceedings{ReginyaNikolaenkoVoronovetal., author = {Reginya, Sergey and Nikolaenko, Vladislav and Voronov, Roman and Soloviev, Alexei and Sikora, Axel and Moschevikin, Alex}, title = {MEMS Sensors Bias Thermal Profiles Classification Using Machine Learning}, series = {Proceedings of the First International Workshop on Stochastic Modeling and Applied Research of Technology, 21-25 September 2018, Petrozavodsk, Russia (CEUR workshop proceedings)}, volume = {2278}, publisher = {RWTH}, address = {Aachen}, issn = {1613-0073}, pages = {17 -- 28}, abstract = {The paper describes the methodology and experimental results for revealing similarities in thermal dependencies of biases of accelerometers and gyroscopes from 250 inertial MEMS chips (MPU-9250). Temperature profiles were measured on an experimental setup with a Peltier element for temperature control. Classification of temperature curves was carried out with machine learning approach. A perfect sensor should not have thermal dependency at all. Thus, only sensors inside the clusters with smaller dependency (smaller total temperature slopes) might be pre-selected for production of high accuracy inertial navigation modules. It was found that no unified thermal profile ("family" curve) exists for all sensors in a production batch. However, obviously, sensors might be grouped according to their parameters. Therefore, the temperature compensation profiles might be regressed for each group. 12 slope coefficients on 5 degrees temperature intervals from 0°C to +60°C were used as the features for the k-means++ clustering algorithm. The minimum number of clusters for all sensors to be well separated from each other by bias thermal profiles in our case is 6. It was found by applying the elbow method. For each cluster a regression curve can be obtained.}, language = {en} } @inproceedings{NaeemHassanPashaetal., author = {Naeem, Aqsa and Hassan, Naveed Ul and Pasha, Muhammad Adeel and Yuen, Chau and Sikora, Axel}, title = {Performance Analysis of TDOA-based Indoor Positioning Systems using Visible LED Lights}, series = {Proceedings of the 4th IEEE International Symposium on Wireless Systems within the International Conferences on Intelligent Data Acquisition and Advanced Computing Systems (IDAACS-SWS), 20-21 September 2018, Lviv, Ukraine}, isbn = {978-1-5386-7587-8 (digital)}, doi = {10.1109/IDAACS-SWS.2018.8525567}, pages = {103 -- 107}, abstract = {Recently, the demand for scalable, efficient and accurate Indoor Positioning Systems (IPS) has seen a rising trend due to their utility in providing Location Based Services (LBS). Visible Light Communication (VLC) based IPS designs, VLC-IPS, leverage Light Emitting Diodes (LEDs) in indoor environments for localization. Among VLC-based designs, Time Difference of Arrival (TDOA) based techniques are shown to provide very low errors in the relative position of receivers. Our considered system consists of five LEDs that act as transmitters and a single receiver (photodiode or image sensor in smart phone) whose position coordinates in an indoor environment are to be determined. As a performance criterion, Cramer Rao Lower Bound (CRLB) is derived for range estimations and the impact of various factors, such as, LED transmission frequency, position of reference LED light, and the number of LED lights, on localization accuracy has been studied. Simulation results show that depending on the optimal values of these factors, location estimation on the order of few centimeters can be realistically achieved.}, language = {en} } @inproceedings{MuellerWalzKieferetal., author = {M{\"u}ller, Thomas and Walz, Andreas and Kiefer, Michael and Doran, Hans Dermot and Sikora, Axel}, title = {Challenges and prospects of communication security in real-time ethernet automation systems}, series = {Proceedings 14th IEEE International Workshop on Factory Communication Systems (WFCS), Imperia, Italy, 2018}, isbn = {978-1-5386-1066-4 (digital)}, doi = {10.1109/WFCS.2018.8402338}, pages = {9}, abstract = {Real-Time Ethernet has become the major communication technology for modern automation and industrial control systems. On the one hand, this trend increases the need for an automation-friendly security solution, as such networks can no longer be considered sufficiently isolated. On the other hand, it shows that, despite diverging requirements, the domain of Operational Technology (OT) can derive advantage from high-volume technology of the Information Technology (IT) domain. Based on these two sides of the same coin, we study the challenges and prospects of approaches to communication security in real-time Ethernet automation systems. In order to capitalize the expertise aggregated in decades of research and development, we put a special focus on the reuse of well-established security technology from the IT domain. We argue that enhancing such technology to become automation-friendly is likely to result in more robust and secure designs than greenfield designs. Because of its widespread deployment and the (to this date) nonexistence of a consistent security architecture, we use PROFINET as a showcase of our considerations. Security requirements for this technology are defined and different well-known solutions are examined according their suitability for PROFINET. Based on these findings, we elaborate the necessary adaptions for the deployment on PROFINET.}, language = {en} } @inproceedings{NguyenSchappacherSikora, author = {Nguyen, Minh Phuong and Schappacher, Manuel and Sikora, Axel}, title = {Extensions of the IEEE 802.15.4 protocol for the usage with highly energy-saving real-time communication}, series = {Tagungsband: MikroSystemTechnik 2015}, booktitle = {Erweiterungen des IEEE802.15.4 f{\"u}r extrem energiesparende echtzeitf{\"a}hige Funkkommunikation}, organization = {VDE/VDI-Gesellschaft Mikroelektronik, Mikrosystem- und Feinwerktechnik (GMM)}, isbn = {978-3-8007-4100-7}, pages = {696 -- 699}, abstract = {Wireless sensor networks have recently found their way into a wide range of applications among which environmental monitoring system has attracted increasing interests of researchers. Such monitoring applications, in general, don way into a wide range of applications among which environmental monitoring system has attracted increasing interests of researc latency requirements regarding to the energy efficiency. Also a challenge of this application is the network topology as the application should be able to be deployed in very large scale. Nevertheless low power consumption of the devices making up the network must be on focus in order to maximize the lifetime of the whole system. These devices are usually battery-powered and spend most of their energy budget on radio transceiver module. A so-called Wake-On-Radio (WoR) technology can be used to achieve a reasonable balance among power consumption, range, complexity and response time. In this paper, some designs for integration of WOR into IEEE 802.1.5.4 are to be discussed, providing an overview of trade-offs in energy consumption while deploying the WoR schemes in a monitoring system.}, language = {en} } @inproceedings{NguyenSchappacherSikoraetal., author = {Nguyen, Minh Phuong and Schappacher, Manuel and Sikora, Axel and Ahmad, Zahoor and Abubakr, Muhammad}, title = {Real-time Water Level Monitoring Using Low-Power Wireless Sensor Network}, series = {embedded world conference 2015, Nuremberg, 24.-26. Feb. 2015}, pages = {9}, abstract = {Environmental Monitoring is an attractive application field for Wireless Sensor Network (WSN). Water Level Monitoring helps to increase the efficiency of water distribution and management. In Pakistan, the world's largest irrigation system covers 90.000 km of channels which needs to be monitored and managed on different levels. Especially the sensor systems for the small distribution channels need to be low energy and low cost. The distribution presents a technical solution for a communication system which is developed in a research project being co-funded by German Academic Exchange Service (DAAD). The communication module is based on IEEE-802.15.4 transceivers which are enhanced through Wake-On-Radio (WOR) to combine low-energy and real-time behavior. On higher layers, IPv6 (6LoWPAN) and corresponding routing protocols like Routing Protocol for Low power and Lossy Networks (RPL) can extend range of the network. The data are stored in a database and can be viewed online via a web interface. Of course, also automatic data analysis can be performed.}, language = {en} } @inproceedings{NguyenJoseSchappacheretal., author = {Nguyen, Minh Phuong and Jose, Joseena M and Schappacher, Manuel and Sikora, Axel}, title = {Wake-On-Radio in Real Wireless Applications}, series = {Proceedings of the Wireless Congress 2016}, address = {M{\"u}nchen}, isbn = {978-3-645-50161-3}, pages = {930 -- 935}, language = {en} } @inproceedings{SerezhinaMoschevikinEvmenchikovetal., author = {Serezhina, Maria and Moschevikin, Alex and Evmenchikov, Ruslan and Sikora, Axel}, title = {Using Radiating Cable for Time-of-Flight CSS Measurements Indoors and Outdoors}, series = {IEEE 8th International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, organization = {IEEE}, isbn = {978-1-4673-8361-5 (digital)}, doi = {10.1109/IDAACS.2015.7340707}, pages = {91 -- 101}, abstract = {The application of leaky feeder (radiating) cables is a common solution for the implementation of reliable radio communication in huge industrial buildings, tunnels and mining environment. This paper explores the possibilities of leaky feeders for 1D and 2D localization in wireless systems based on time of flight chirp spread spectrum technologies. The main focus of this paper is to present and analyse the results of time of flight and received signal strength measurements with leaky feeders in indoor and outdoor conditions. The authors carried out experiments to compare ranging accuracy and radio coverage area for a point-like monopole antenna and for a leaky feeder acting as a distributed antenna. In all experiments RealTrac equipment based on nanoLOC radio standard was used. The estimation of the most probable path of a chirp signal going through a leaky feeder was calculated using the ray tracing approach. The typical non-line-of-sight errors profiles are presented. The results show the possibility to use radiating cables in real time location technologies based on time-of-flight method.}, language = {en} } @inproceedings{SikoraSchappacher, author = {Sikora, Axel and Schappacher, Manuel}, title = {A Highly Scalable IEEE802.11p Subsystem Using Communication and Localization for Increased Vehicular Safety}, series = {International Journal of Electrical Energy 2013 International Conference on Control, Robotics and Cybernetics, Mal{\´e} (Maldives)}, volume = {1}, number = {2/2013}, doi = {10.12720/ijoee.1.2.80-85}, pages = {80 -- 85}, language = {en} } @inproceedings{SikoraJaeckleRahusenetal., author = {Sikora, Axel and J{\"a}ckle, Daniel and Rahusen, David and Weber, Patrick}, title = {Flexible and Open Source Usage of LoRaWAN}, series = {Proceedings of the Wireless Congress 2016}, publisher = {Weka Fachmedien GmbH}, address = {Haar}, isbn = {978-3-645-50161-3}, pages = {547 -- 571}, language = {en} } @inproceedings{JaeckleSikora, author = {J{\"a}ckle, Daniel and Sikora, Axel}, title = {Thermische Optimierung des Prozess-Scheduling f{\"u}r Multicore-Prozessoren}, series = {Workshop der Multiprojekt-Chip-Gruppe Baden-W{\"u}rttemberg, Pforzheim Februar 2014}, volume = {51}, organization = {Hochschule Ulm}, issn = {1868-9221}, pages = {54 -- 64}, abstract = {Die zunehmende Anzahl von Transistoren mit immer kleineren Strukturgr{\"o}ßen f{\"u}hrt zu einer zunehmenden Leistungsaufnahme in modernen Prozessoren. Das gilt insbesondere f{\"u}r High-End Prozessoren, die mit einer hohen Taktfrequenz betrieben werden. Die aufgenommene Leistung wird in W{\"a}rme umgewandelt, die in einer Temperaturerh{\"o}hung der Prozessoren resultiert. Hohe Betriebstemperaturen verursachen u.a. eine verringerte Rechenleistung, eine k{\"u}rzere Lebensdauer des Prozessors und h{\"o}here Leckstr{\"o}me. Aus diesen Gr{\"u}nden wird aktives, dynamisches thermisches Management immer wichtiger. Dieser Beitrag stellt eine Erweiterung zu dem Standard- Linux-Scheduler in der Kernel-Version 3.0 f{\"u}r eingebettete Systeme vor: einen PID-Regler, der unter Angabe einer Solltemperatur eine dynamische Frequenz- und Spannungsskalierung durchf{\"u}hrt. Die Experimente auf dem Freescale LMX6 Quadcore-Prozessor zeigen, dass der PID-Regler die Betriebstemperatur des Prozessors an die Solltemperatur regeln kann. Er ist die Grundlage f{\"u}r eine in Zukunft zu entwickelnde pr{\"a}diktive Regelung.}, language = {de} } @inproceedings{SikoraLillSchappacheretal., author = {Sikora, Axel and Lill, Dirk and Schappacher, Manuel and Gutjahr, Simon and Gerber, Eugen}, title = {Development of Car2X Communication and Localization PHY and MAC Protocol Following Iterative Spiral Model Using Simulation and Emulation}, series = {5th International Workshop on Communication Technologies for Vehicles (Nets4Cars/Nets4Trains 2013)}, volume = {2013}, isbn = {3-642-37973-7}, pages = {136 -- 145}, language = {en} } @inproceedings{SchappacherSchmittSikoraetal., author = {Schappacher, Manuel and Schmitt, Edgar and Sikora, Axel and Weber, Patrick and Yushev, Artem}, title = {A Flexible, Modular, Open-Source Implementation of 6LoWPAN}, series = {8th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications}, organization = {IEEE}, isbn = {978-1-4673-8361-5 (digital)}, doi = {10.1109/IDAACS.2015.7341421}, pages = {838 -- 844}, abstract = {6LoWPAN (IPv6 over Low Power Wireless Personal Area Networks) is gaining more and more attraction for the seamless connectivity of embedded devices for the Internet of Things. It can be observed that most of the available solutions are following an open source approach, which significantly leads to a fast development of technologies and of markets. Although the currently available implementations are in a pretty good shape, all of them come with some significant drawbacks. It was therefore decided to start the development of an own implementation, which takes the advantages from the existing solutions, but tries to avoid the drawbacks. This paper discussed the reasoning behind this decision, describes the implementation and its characteristics, as well as the testing results. The given implementation is available as open-source project under [15].}, language = {en} } @inproceedings{Sikora, author = {Sikora, Axel}, title = {Design, Simulation, and Verification of Highly Portable and Flexible Communication Stacks for Automatic Meter Reading (AMR)}, series = {Proceedings SENSOR 2013 AMA Conferences 2013 2013-05-14 - 2013-05-16 N{\"u}rnberg}, isbn = {978-3-9813484-3-9}, doi = {10.5162/sensor2013/C6.2}, pages = {442 -- 447}, language = {en} } @inproceedings{MoschevikinGalovReginyaetal., author = {Moschevikin, Alex and Galov, Aleksandr and Reginya, Sergey and Volkov, Alexander and Sikora, Axel}, title = {The Impact of NLOS Components in Time-of- Flight Networks for Indoor Positioning Systems}, series = {7th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems}, doi = {10.1109/IDAACS.2013.6662727}, pages = {455 -- 460}, language = {en} } @inproceedings{SikoraWernerGrafmueller, author = {Sikora, Axel and Werner, Rico and Grafm{\"u}ller, Jan Oliver}, title = {Design and Implementation of an Energy Aware Routing Extension for Energy Autarkic Wireless M-Bus Networks}, series = {International Workshop on Energy Efficient Wireless Communications and Networking}, doi = {10.1109/ICACCI.2013.6637392}, language = {en} } @inproceedings{SikoraWernerVillalongaetal., author = {Sikora, Axel and Werner, Rico and Villalonga, Pancra{\c{c}} and Buqa, Hilmi and Becker, Philipp and Hoffmann, Daniel and Willmann, Alexander}, title = {Development of an Energy-Autarkic Water Meter Using Wireless M-Bus based on TinyOS platform}, series = {VDE Mikrosystemtechnik-Kongress}, isbn = {978-3-8007-3555-6}, language = {en} } @inproceedings{Sikora, author = {Sikora, Axel}, title = {Implementation of Standardized Secure Smart Meter Communication}, series = {Proceedings of 2013 35th International Telecommunications Energy Conference 'Smart Power and Efficiency' (INTELEC)}, language = {en} } @inproceedings{MikovMoschevikinFedorovetal., author = {Mikov, Aleksandr and Moschevikin, Alex and Fedorov, Alexander and Sikora, Axel}, title = {A Localization System Using Inertial Measurement Units from Wireless Commercial Handheld Devices}, series = {4th International Conference on Indoor Positioning and Indoor Navigation, Montbeliard-Belfort, France}, volume = {2013}, issn = {978-1-4799-4043-1}, doi = {10.1109/IPIN.2013.6817924}, pages = {28 -- 31}, language = {en} } @inproceedings{SchappacherSikora, author = {Schappacher, Manuel and Sikora, Axel}, title = {Results of Cooperative Localization and Communication System for C2X-Applications}, series = {Wireless Congress : Systems \& Applications vom 6. - 7. November 2013 in M{\"u}nchen}, volume = {2013}, isbn = {978-3-645-50128-6}, language = {en} } @inproceedings{SikoraSchappacher, author = {Sikora, Axel and Schappacher, Manuel}, title = {A highly scalable IEEE802.11p communication and localization subsystem for autonomous urban driving}, series = {International Conference on Connected Vehicles \& Expo (ICCVE)2013}, isbn = {978-1-4799-2491-2}, issn = {2378-1297}, doi = {10.1109/ICCVE.2013.6799894}, language = {en} } @inproceedings{MamoSikora, author = {Mamo, Fesseha Tsegaye and Sikora, Axel}, title = {Application Protocols for the IPv6-based Internet of Things}, series = {Embedded World Conference, Nuremberg, 24.-26. Feb. 2015}, volume = {2015}, language = {en} } @inproceedings{MamoSikora, author = {Mamo, Fesseha Tsegaye and Sikora, Axel}, title = {Implementation of Standardized 6LoWPAN Based Application Layer Protocols}, series = {8th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications}, organization = {IEEE}, isbn = {978-1-4673-8361-5 (digital)}, doi = {10.1109/IDAACS.2015.7341417}, pages = {817 -- 822}, abstract = {6LoWPAN (IPv6 over Low Power Wireless Personal Area Networks) is gaining more and more attraction for the seamless connectivity of embedded devices for the Internet of Things (IoT). Whereas the lower layers (IEEE802.15.4 and 6LoWPAN) are already well defined and consolidated with regard to frame formats, header compression, routing protocols and commissioning procedures, there is still an abundant choice of possibilities on the application layer. Currently, various groups are working towards standardization of the application layer, i.e. the ETSI Technical Committee on M2M, the IP for Smart Objects (IPSO) Alliance, Lightweight M2M (LWM2M) protocol of the Open Mobile Alliance (OMA), and OneM2M. This multitude of approaches leaves the system developer with the agony of choice. This paper selects, presents and explains one of the promising solutions, discusses its strengths and weaknesses, and demonstrates its implementation.}, language = {en} } @inproceedings{MamoYushevWalzetal., author = {Mamo, Fesseha Tsegaye and Yushev, Artem and Walz, Andreas and Schappacher, Manuel and Sikora, Axel and Scherzinger, Clemens and Ketterer, Lionel}, title = {Comparison of Cryptographic Implementations for Embedded TLS}, series = {Embedded world Conference 23.-25. Feb. 2016, N{\"u}rnberg}, organization = {Fraunhofer IPMS}, pages = {812 -- 817}, language = {en} } @inproceedings{LillSikora, author = {Lill, Dirk and Sikora, Axel}, title = {Wireless M-Bus and its Real-World Flavors}, series = {Embedded World Conference, 26.-28. Feb 2013, Nuremberg}, language = {en} } @inproceedings{NguyenSchappacherSikoraetal., author = {Nguyen, Minh Phuong and Schappacher, Manuel and Sikora, Axel and Groza, Voicu F.}, title = {Extensions of the IEEE802.15.4 Protocol for Ultra-Low Energy Real-Time Communication}, series = {IEEE Xplore}, publisher = {IEEE}, organization = {IEEE}, doi = {10.1109/I2MTC.2016.7520415}, abstract = {Wireless sensor networks have found their way into a wide range of applications among which environmental monitoring systems have attracted increasing interests of researchers. The main challenges for the applications are scalability of the network size and energy efficiency of the spatially distributed motes. These devices are mostly battery-powered and spend most of their energy budget on the radio transceiver module. A so-called Wake-On-Radio (WOR) technology can be used to achieve a reasonable balance among power consumption, range, complexity and response time. In this paper, a novel design for integration of WOR into IEEE802.1.5.4 is presented, which flexibly allows trade-offs in energy consumption between sender and receiver station, between real-time capability and energy consumption. For identical behavior, the proposed scheme is significantly more efficient than other schemes, which were proposed in recent publications, while preserving backward compatibility with standard IEEE802.15.4 transceivers.}, language = {en} } @inproceedings{MoschevikinTsvetkovAlekseevetal., author = {Moschevikin, Alex and Tsvetkov, Eugene and Alekseev, Anton and Sikora, Axel}, title = {Investigations on Passive Channel Impulse Response of Ultra Wide Band Signals For Monitoring and Safety Applications}, series = {2016 3rd International Symposium on Wireless Systems within the Conferences on Intelligent Data Acquisition and Advanced Computing Systems (IDAACS-SWS)}, organization = {IEEE}, isbn = {978-1-5090-4317-0 (digital)}, doi = {10.1109/IDAACS-SWS.2016.7805795}, pages = {8}, abstract = {Ultra wide band (UWB) signals are well suited both for short-range wireless communication and for high-precision localization applications. Channel impulse response (CIR) analysis in UWB systems is a major element in localization estimation. In this paper, practical aspects of CIR are presented. I.e. a technique for the construction of the accumulated echo-gram of a multipath delayed signal is proposed. Decawave hardware was used to demonstrate the technique of analysis of fine structure of signals with a sub-nanosecond resolution. Temporal stability, reliability and two-way characteristics of such echo-grams are discussed as well. The results of using two EVK1000 radio modules as a radar installation to detect a target in indoor environments prove that a low cost UWB intrusion detection and through-the-wall-vision systems might be developed using the proposed technique.}, language = {en} } @inproceedings{MamoSikora, author = {Mamo, Fesseha Tsegaye and Sikora, Axel}, title = {An Overview on Alliances and Ecosystems for Home and Building Automation}, series = {Embedded world Conference 2016. Exhibition \& Conference : Nuremberg, Germany, February 23-25, 2016}, publisher = {WEKA Fachmedien}, address = {Haar}, isbn = {978-3-645-50159-0}, pages = {83 -- 91}, language = {en} } @inproceedings{MamoYushevWalzetal., author = {Mamo, Fesseha Tsegaye and Yushev, Artem and Walz, Andreas and Schappacher, Manuel and Sikora, Axel}, title = {Wege zu zukunftssicheren Kommunikationsprotokollen f{\"u}r das Smart Home - auf allen Ebenen}, series = {Internet der Dinge : VDE-Kongress 2016 : 07.11.2016 - 08.11.2016 in Mannheim, Deutschland}, publisher = {VDE Verlag}, address = {Berlin}, organization = {VDE}, isbn = {978-3-8007-4308-7}, pages = {1 -- 4}, abstract = {Die Vielfalt der Protokolle, die praktisch auf allen Ebenen der Netzwerkkommunikation zu ber{\"u}cksichtigen ist, stellt eine der großen Herausforderungen bei der fortschreitenden Automatisierung des intelligenten Hauses dar. Unter dem {\"U}berbegriff Internet der Dinge (Internet of Things) entstehen gegenw{\"a}rtig zahlreiche neue Entwicklungen, Standards, Allianzen und so genannte {\"O}kosysteme. Diese haben die Absicht einer horizontalen Integration gewerke{\"u}bergreifender Anwendungen und verfolgen fast alle das Ziel, die Situation zu vereinfachen, die Entwicklungen zu beschleunigen und Markterfolge zu erreichen. Leider macht diese Vielfalt momentan die Welt aber eher noch komplexer und bringt damit das Risiko mit sich, genau das Gegenteil der urspr{\"u}nglichen Absichten zu erreichen. Dieser Beitrag versucht, die Entwicklungen m{\"o}glichst systematisch zu kategorisieren und m{\"o}gliche L{\"o}sungsans{\"a}tze zu beschreiben.}, language = {de} } @inproceedings{PrasetyoYushevSikora, author = {Prasetyo, Junaedi Adi and Yushev, Artem and Sikora, Axel}, title = {Investigations On The Performance Of Bluetooth Enabled Mesh Networking}, series = {2016 3rd International Symposium on Wireless Systems within the Conferences on Intelligent Data Acquisition and Advanced Computing Systems (IDAACS-SWS)}, organization = {IEEE}, isbn = {978-1-5090-4317-0 (digital)}, doi = {10.1109/IDAACS-SWS.2016.7805786}, pages = {56 -- 61}, abstract = {The Bluetooth community is in the process to develop mesh technology. This is highly promising as Bluetooth is widely available in Smart Phones and Tablet PCs, allowing an easy access to the Internet of Things. In this paper work, we investigate the performance of Bluetooth enabled mesh networking that we performed to identify the strengths and weaknesses. A demonstrator for this protocol has been implemented by using the Fruity Mesh protocol implementation. Extensive test cases have been executed to measure the performance, the reliability, the power consumption and the delay. For this, an Automated Physical Testbed (APTB), which emulates the physical channels has been used. The results of these measurements are considered useful for the real implementation of Bluetooth; not only for home and building automation, but also for industrial automation.}, language = {en} } @inproceedings{SikoraElayanithottathilYushevetal., author = {Sikora, Axel and Elayanithottathil, Jubin Sebastian and Yushev, Artem and Schmitt, Edgar and Schappacher, Manuel}, title = {Automated Physical Testbeds for Emulation of Wireless Networks}, series = {International Conference on Measurement Instrumentation and Electronics (ICMIE 2016)}, organization = {MATEC Web of Conferences}, doi = {10.1051/matecconf/20167506006}, pages = {1 -- 5}, abstract = {Institute of Reliable Embedded Systems and Communication Electronics, Offenburg University of Applied Sciences, Germany has developed an automated testing environment, Automated Physical TestBeds (APTB), for analyzing the performance of wireless systems and its supporting protocols. Wireless physical networking nodes can connect to this APTB and the antenna output of this attaches with the RF waveguides. To model the RF environment this RF waveguides then establish wired connection among RF elements like splitters, attenuators and switches. In such kind of set up it's well possible to vary the path characteristics by altering the attenuators and switches. The major advantage of using APTB is the possibility of isolated, well controlled, repeatable test environment in various conditions to run statistical analysis and even to execute regression tests. This paper provides an overview of the design and implementation of APTB, demonstrates its ability to automate test cases, and its efficiency.}, language = {en} } @inproceedings{WeberJaeckleRahusenetal., author = {Weber, Patrick and J{\"a}ckle, Daniel and Rahusen, David and Sikora, Axel}, title = {IPv6 over LoRaWAN™}, series = {2016 3rd International Symposium on Wireless Systems within the Conferences on Intelligent Data Acquisition and Advanced Computing Systems (IDAACS-SWS)}, organization = {IEEE}, isbn = {978-1-5090-4317-0 (digital)}, doi = {10.1109/IDAACS-SWS.2016.7805790}, pages = {5}, abstract = {Although short-range wireless communication explicitly targets local and regional applications, range continues to be a highly important issue. The range directly depends on the so-called link budget, which can be increased by the choice of modulation and coding schemes. The recent transceiver generation in particular comes with extensive and flexible support for software-defined radio (SDR). The SX127× family from Semtech Corp. is a member of this device class and promises significant benefits for range, robust performance, and battery lifetime compared to competing technologies. This contribution gives a short overview of the technologies to support Long Range (LoRa™) and the corresponding Layer 2 protocol (LoRaWAN™). It particularly describes the possibility to combine the Internet Protocol, i.e. IPv6, into LoRaWAN™, so that it can be directly integrated into a full-fledged Internet of Things (IoT). The proposed solution, which we name 6LoRaWAN, has been implemented and tested; results of the experiments are also shown in this paper.}, language = {en} } @inproceedings{SikoraAhmadPashaetal., author = {Sikora, Axel and Ahmad, Zahoor and Pasha, Muhammad Adeel and Ahmad, Awais and Abubakr, Muhammad and Masud, Shahid and Schappacher, Manuel}, title = {Performance Evaluation of IEEE 802.15.4-Compliant Smart Water Meters for Automating Large-Scale Waterways}, series = {Proceedings of the 2017 IEEE 9th International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, volume = {2}, organization = {IEEE}, isbn = {978-1-5386-0697-1 (digital)}, doi = {10.1109/IDAACS.2017.8095189}, pages = {746 -- 751}, abstract = {Climate change and resultant scarcity of water are becoming major challenges for countries around the world. With the advent of Wireless Sensor Networks (WSN) in the last decade and a relatively new concept of Internet of Things (IoT), embedded systems developers are now working on designing control and automation systems that are lower in cost and more sustainable than the existing telemetry systems for monitoring. The Indus river basin in Pakistan has one of the world's largest irrigation systems and it is extremely challenging to design a low-cost embedded system for monitoring and control of waterways that can last for decades. In this paper, we present a hardware design and performance evaluation of a smart water metering solution that is IEEE 802.15.4-compliant. The results show that our hardware design is as powerful as the reference design, but allows for additional flexibility both in hardware and in firmware. The indigenously designed solution has a power added efficiency (PAE) of 24.7\% that is expected to last for 351 and 814 days for nodes with and without a power amplifier (PA). Similarly, the results show that a broadband communication (434 MHz) over more than 3km can be supported, which is an important stepping stone for designing a complete coverage solution of large-scale waterways.}, language = {en} } @inproceedings{SikoraAhmadPashaetal., author = {Sikora, Axel and Ahmad, Awais and Pasha, Muhammad Adeel and Ahmad, Zahoor and Masud, Shahid}, title = {Energy Efficient Sensor Network Routing (EESNR) Protocol For Large Distributed Environmental Monitoring Applications}, series = {Proceedings of the 2017 IEEE 9th International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, volume = {2}, organization = {IEEE}, isbn = {978-1-5386-0697-1 (digital)}, doi = {10.1109/IDAACS.2017.8095188}, pages = {740 -- 745}, abstract = {Due to climate change and scarcity of water reservoirs, monitoring and control of irrigation systems is now becoming a major focal area for researchers in Cyber-Physical Systems (CPS). Wireless Sensor Networks (WSNs) are rapidly finding their way in the field of irrigation and play the key role as data gathering technology in the domain of IoT and CPS. They are efficient for reliable monitoring, giving farmers an edge to take precautionary measures. However, designing an energy-efficient WSN system requires a cross-layer effort and energy-aware routing protocols play a vital role in the overall energy optimization of a WSN. In this paper, we propose a new hierarchical routing protocol suitable for large area environmental monitoring such as large-scale irrigation network existing in the Punjab province of Pakistan. The proposed protocol resolves the issues faced by traditional multi-hop routing protocols such as LEACH, M-LEACH and I-LEACH, and enhances the lifespan of each WSN node that results in an increased lifespan of the whole network. We used the open-source NS3 simulator for simulation purposes and results indicate that our proposed modifications result in an average 27.8\% increase in lifespan of the overall WSN when compared to the existing protocols.}, language = {en} } @inproceedings{SikoraWalz, author = {Sikora, Axel and Walz, Andreas}, title = {eTPL: An Enhanced Version of the TLS Presentation Language Suitable for Automated Parser Generation}, series = {Proceedings of the 2017 IEEE 9th International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, volume = {2}, organization = {IEEE}, isbn = {978-1-5386-0697-1 (digital)}, doi = {10.1109/IDAACS.2017.8095200}, pages = {810 -- 814}, abstract = {The specification of the Transport Layer Security (TLS) protocol defines its own presentation language used for the purpose of semi-formally describing the structure and on-the-wire format of TLS protocol messages. This TLS Presentation Language (TPL) is more expressive and concise than natural language or tabular descriptions, but as a result of its limited objective has a number of deficiencies. We present eTPL, an enhanced version of TPL that improves its expressiveness, flexibility, and applicability to non-TLS scenarios. We first define a generic model that describes the parsing of binary data. Based on this, we propose language constructs for TPL that capture important information which would otherwise have to be picked manually from informal protocol descriptions. Finally, we briefly introduce our software tool etpl-tool which reads eTPL definitions and automatically generates corresponding message parsers in C++. We see our work as a contribution supporting sniffing, debugging, and rapid-prototyping of wired and wireless communication systems.}, language = {en} } @inproceedings{SikoraSchappacherZimmermannetal.2017, author = {Sikora, Axel and Schappacher, Manuel and Zimmermann, Lukas and Mars, Nidhal}, title = {Development of Thread-compatible Open Source Stack}, series = {Journal of Physics: Conference Series}, volume = {870}, publisher = {IOP Publishing Ltd}, issn = {1742-6588 (Print)}, doi = {10.1088/1742-6596/870/1/012001}, pages = {012001}, year = {2017}, abstract = {The Thread protocol is a recent development based on 6LoWPAN (IPv6 over IEEE 802.15.4), but with extensions regarding a more media independent approach, which - additionally - also promises true interoperability. To evaluate and analyse the operation of a Thread network a given open source 6LoWPAN stack for embedded devices (emb::6) has been extended in order to comply with the Thread specification. The implementation covers Mesh Link Establishment (MLE) and network layer functionality as well as 6LoWPAN mesh under routing mechanism based on MAC short addresses. The development has been verified on a virtualization platform and allows dynamical establishment of network topologies based on Thread's partitioning algorithm.}, language = {en} } @inproceedings{SikoraSchappacherNsiah, author = {Sikora, Axel and Schappacher, Manuel and Nsiah, Kofi Atta}, title = {Dynamic mapping of EDDL device descriptions to OPC UA}, series = {Journal of Physics: Conference Series}, volume = {870}, publisher = {IOP Publishing Ltd}, issn = {1742-6588 (Print)}, doi = {10.1088/1742-6596/870/1/012006}, pages = {012006}, abstract = {OPC UA (Open Platform Communications Unified Architecture) is already a well-known concept used widely in the automation industry. In the area of factory automation, OPC UA models the underlying field devices such as sensors and actuators in an OPC UA server to allow connecting OPC UA clients to access device-specific information via a standardized information model. One of the requirements of the OPC UA server to represent field device data using its information model is to have advanced knowledge about the properties of the field devices in the form of device descriptions. The international standard IEC 61804 specifies EDDL (Electronic Device Description Language) as a generic language for describing the properties of field devices. In this paper, the authors describe a possibility to dynamically map and integrate field device descriptions based on EDDL into OPCUA.}, language = {en} } @inproceedings{SikoraMamoRathfelder, author = {Sikora, Axel and Mamo, Fesseha Tsegaye and Rathfelder, Christoph}, title = {Legacy to Industry 4.0: A Profibus Sniffer}, series = {Journal of Physics: Conference Series}, volume = {870}, publisher = {IOP Publishing}, issn = {1742-6588 (Print)}, doi = {10.1088/1742-6596/870/1/012002}, pages = {012002}, abstract = {Legacy industrial communication protocols are proved robust and functional. During the last decades, the industry has invented completely new or advanced versions of the legacy communication solutions. However, even with the high adoption rate of these new solutions, still the majority industry applications run on legacy, mostly fieldbus related technologies. Profibus is one of those technologies that still keep on growing in the market, albeit a slow in market growth in recent years. A retrofit technology that would enable these technologies to connect to the Internet of Things, utilize the ever growing potential of data analysis, predictive maintenance or cloud-based application, while at the same time not changing a running system is fundamental.}, language = {en} } @inproceedings{SikoraMoschevikinLunkovetal., author = {Sikora, Axel and Moschevikin, Alex and Lunkov, Pavel V. and Fedorov, Alexander and Maslennikov, Evgeny I.}, title = {Hardware and Software Architecture of Multi MEMS Sensor Inertial Module}, series = {24th Saint Petersburg International Conference on Integrated Navigation Systems (ICINS), 29-31 May 2017, St. Petersburg, Russia}, organization = {IEEE}, isbn = {978-1-5386-0978-1}, doi = {10.23919/ICINS.2017.7995643}, pages = {366 -- 369}, abstract = {The paper describes the hardware and software architecture of the developed multi MEMS sensor prototype module, consisting of ARM Cortex M4 STM32F446 microcontroller unit, five 9-axis inertial measurement units MPU9255 (3D accelerometer, 3D gyroscope, 3D magnetometer and temperature sensor) and a BMP280 barometer. The module is also equipped with WiFi wireless interface (Espressif ESP8266 chip). The module is constructed in the form of a truncated pyramid. Inertial sensors are mounted on a special basement at different angles to each other to eliminate hardware sensors drifts and to provide the capability for self-calibration. The module fuses information obtained from all types of inertial sensors (acceleration, rotation rate, magnetic field and air pressure) in order to calculate orientation and trajectory. It might be used as an Inertial Measurement Unit, Vertical Reference Unit or Attitude and Heading Reference System.}, language = {en} } @inproceedings{SikoraSchwaabReginyaetal., author = {Sikora, Axel and Schwaab, Manuel and Reginya, Sergey and Abramov, Evgeniy V.}, title = {Measurement Analysis of Multiple MEMS Sensor Array}, series = {24th Saint Petersburg International Conference on Integrated Navigation Systems (ICINS), 29-31 May 2017, St. Petersburg, Russia}, organization = {IEEE}, isbn = {978-1-5386-0978-1}, doi = {10.23919/ICINS.2017.7995650}, pages = {392 -- 395}, abstract = {The low cost and small size of MEMS inertial sensors allows their combination into a multi sensor module in order to improve performance. However the different linear accelerations measured on different places on a rotating rigid body have to be considered for the proper fusion of the measurements. The errors in measurement of MEMS inertial sensors include deterministic imperfection, but also random noise. The gain in accuracy of using multiple sensors depends strongly on the correlation between these errors from the different sensors. Although for sensor fusion it usually assumed that the measurement errors of different sensors are uncorrelated, estimation theory shows that for the combination of the same type of sensors actually a negative correlation will be more beneficial. Therefore we describe some important and often neglected considerations for the combination of several sensors and also present some preliminary results with regard to the correlation of measurements from a simple multi sensor setup.}, language = {en} } @inproceedings{SikoraSchappacherYushevetal., author = {Sikora, Axel and Schappacher, Manuel and Yushev, Artem and Moni, Mahbuba}, title = {VTENN - A Virtualized Testbed for Embedded Networking Nodes}, series = {Proceedings of the 2017 IEEE 9th International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS)}, volume = {2}, organization = {IEEE}, isbn = {978-1-5386-0697-1 (digital)}, doi = {10.1109/IDAACS.2017.8095198}, pages = {797 -- 803}, abstract = {A novel approach of a test environment for embedded networking nodes has been conceptualized and implemented. Its basis is the use of virtual nodes in a PC environment, where each node executes the original embedded code. Different nodes run in parallel, connected via so-called virtual channels. The environment allows to modifying the behavior of the virtual channels as well as the overall topology during runtime to virtualize real-life networking scenarios. The presented approach is very efficient and allows a simple description of test cases without the need of a network simulator. Furthermore, it speeds up the process of developing new features as well as it supports the identification of bugs in wireless communication stacks. In combination with powerful test execution systems, it is possible to create a continuous development and integration flow.}, language = {en} } @inproceedings{JoseSikoraSchappacheretal., author = {Jose, Joseena M and Sikora, Axel and Schappacher, Manuel and Nguyen, Minh Phuong}, title = {Integration and Analysis of an Extended IEEE 802.15.4 Modules with SmartMAC and Wake-on-Radio Functions into the Network Simulator NS3}, series = {2016 3rd International Symposium on Wireless Systems within the Conferences on Intelligent Data Acquisition and Advanced Computing Systems (IDAACS-SWS)}, organization = {IEEE}, isbn = {978-1-5090-4317-0 (digital)}, doi = {10.1109/IDAACS-SWS.2016.7805778}, pages = {19 -- 23}, abstract = {Wireless Sensor Networks (WSN) have emerged as interesting topic in the research community due to its manifold applications. One of the main challenges of this field is the energy consumption of the nodes, which typically is quite restricted due to the required lifetime of such WSNs. To solve that problem several energy-saving MAC protocols have been developed so far. One of them recently presented by the authors is the so-called SmartMAC as an extension to the IEEE802.15.4 standard. In this paper, we present the implementation details of the porting of the SmartMAC protocol to the discrete event network simulator NS3. We develop this module for NS3 to simulate the performance, multi node execution, and multi node configuration. Along with this model, we also present an energy model for the evaluation of the energy consumption. The current implementation in NS3 is based on the LR-WPAN (Low-Rate Wireless Personal Area Networks) as specified by the IEEE802.15.4 (2006) standard. The simulation results show that the SmartMAC with its sleep and wake-up mechanisms for the transceivers, is significantly more efficient than the current NS3 MAC (Medium Access Control) scheme.}, language = {en} } @inproceedings{SikoraRiskeSchappacher, author = {Sikora, Axel and Riske, Alexander and Schappacher, Manuel}, title = {Entwicklung eines DGPS-gest{\"u}tzten Fahrdynamikmesssystems unter Verwendung des FPGAs Zynq-7000 mit einem Dual-Core Bare-Metal asymmetrischen Multiprozessorsystem}, series = {Tagungsband zum Workshop der Multiprojekt-Chip-Gruppe Baden-W{\"u}rttemberg, Karlsruhe, 5. Februar 2016}, volume = {55}, organization = {Hochschule Karlsruhe}, issn = {1868-9221}, pages = {23 -- 28}, abstract = {Die neueste Generation von programmierbaren Logikbausteinen verf{\"u}gt neben den konfigurierbaren Logikzellen {\"u}ber einen oder mehrere leistungsf{\"a}hige Mikroprozessoren. In dieser Arbeit wird gezeigt, wie ein bestehendes Zwei-Chip-System auf einen Xilinx Zynq 7000 mit zwei ARM A9-Cores migriert wird. Bei dem System handelt es sich um das „GPS-gest{\"u}tzte Kreisel-system ADMA" des Unternehmens GeneSys. Die neue L{\"o}sung verbessert den Datenaustausch zwischen dem ersten Mikroprozessor zur digitalen Signalverarbeitung und dem zweiten Prozessor zur Ablaufsteuerung durch ein Shared Memory. F{\"u}r die schnelle und echtzeitf{\"a}hige Daten{\"u}bertragung werden zahlreiche hochbitratige Schnittstellengenutzt.}, language = {de} } @inproceedings{SikoraSchappacherYushev, author = {Sikora, Axel and Schappacher, Manuel and Yushev, Artem}, title = {A Novel Virtualized Testbed for Embedded Networking Nodes (VTENN)}, series = {Proceedings of the 2017 IEEE International Instrumentation and Measurement Technology Conference (I2MTC)}, organization = {IEEE}, isbn = {978-1-5090-3596-0 (digital)}, doi = {10.1109/I2MTC.2017.7969667}, pages = {6}, abstract = {A novel approach of a testbed for embedded networking nodes has been conceptualized and implemented. It is based on the use of virtual nodes in a PC environment, where each node executes the original embedded code. Different nodes are running in parallel and are connected via so-called virtual interfaces. The presented approach is very efficient and allows a simple description of test cases without the need of a network simulator. Furthermore, it speeds up the process of developing new features.}, language = {en} } @inproceedings{SharmaSairamYadavetal., author = {Sharma, Ravi and Sairam, Ashok Singh and Yadav, Akash and Sikora, Axel}, title = {Tunable Synchronization in Duty-cycled Wireless Sensor Networks}, series = {2016 IEEE International Conference on Advanced Networks and Telecommunications Systems (ANTS)}, isbn = {978-1-5090-2193-2 (digital)}, doi = {10.1109/ANTS.2016.7947782}, pages = {856 -- 860}, abstract = {In this work, we consider a duty-cycled wireless sensor network with the assumption that the on/off schedules are uncoordinated. In such networks, as all nodes may not be awake during the transmission of time synchronization messages, nodes will require to re-transmit the synchronization messages. Ideally a node should re-transmit for the maximum sleep duration to ensure that all nodes are synchronized. However, such a proposition will immensely increase the energy consumption of the nodes. Such a situation demands that there is an upper bound of the number of retransmissions. We refer to the time a node spends in re-transmission of the control message as broadcast duration. We ask the question, what should be the broadcast duration to ensure that a certain percentage of the available nodes are synchronized. The problem to estimate the broadcast duration is formulated so as to capture the probability threshold of the nodes being synchronized. Results show the proposed analytical model can predict the broadcast duration with a given lower error margin under real world conditions, thus demonstrating the efficiency of our solution.}, language = {en} } @inproceedings{ElayanithottathilYushevSikoraetal., author = {Elayanithottathil, Jubin Sebastian and Yushev, Artem and Sikora, Axel and Schappacher, Manuel and Prasetyo, Junaedi Adi}, title = {Performance Investigation Of 6Lo With RPL Mesh Networking For Home And Building Automation}, series = {2016 3rd International Symposium on Wireless Systems within the Conferences on Intelligent Data Acquisition and Advanced Computing Systems (IDAACS-SWS)}, organization = {IEEE}, isbn = {978-1-5090-4317-0 (digital)}, doi = {10.1109/IDAACS-SWS.2016.7805801}, pages = {127 -- 133}, abstract = {IPv6 over resource-constrained devices (6Lo) emerged as a de-facto standard for the Internet of Things (IoT) applications especially in home and building automation systems. We provide results of an investigation of the applicability of 6LoWPAN with RPL mesh networks for home and building automation use cases. The proper selection of Trickle parameters and neighbor reachable time-outs is important in the RPL protocol suite to respond efficiently to any path failure. These parameters were analyzed in the context of energy consumption w.r.t the number of control packets. The measurements were performed in an Automated Physical Testbeds (APTB). The results match the recommendation by RFC 7733 for selecting various parameters of RPL protocol suite. This paper shows the relationship between various RPL parameters and control traffic overhead during network rebuild. Comparative measurement results with Bluetooth Low Energy (BLE) in this work showed that 6Lo with RPL outperformed BLE in this use case with less control traffic overheads.}, language = {en} } @inproceedings{YushevWalzSikora, author = {Yushev, Artem and Walz, Andreas and Sikora, Axel}, title = {Securing Embedded Communication with TLS1.2}, series = {embedded world conference 2015, Nuremberg, 24.-26. Feb. 2015}, language = {en} } @inproceedings{YushevSikoraElayanithottathil, author = {Yushev, Artem and Sikora, Axel and Elayanithottathil, Jubin Sebastian}, title = {Open source 6Lo protocol stack for wireless embedded systems}, series = {Wireless Telecommunications Symposium (WTS)}, isbn = {978-1-5090-0314-3}, doi = {10.1109/WTS.2016.7482044}, pages = {7}, abstract = {In the last decade, IPv6 over Low power Wireless Personal Area Networks (IEEE802.15.4), also known as 6LoWPAN, has well evolved as a primary contender for short range wireless communications and holds the promise of an Internet of Things, which is completely based on the Internet Protocol. The authors' team has developed a 6LoWPAN protocol stack in C language, the stack without the necessity to use a specific design environment or operating system. It is highly flexible, modular, and portable and can be enhanced by several interesting modules, like a Wake-On-Radio-(WOR) MAC layer or a TLS1.2 based security sublayer. The stack is made available as open source at https://github.com/hso-esk/emb6. It was extensively tested on the Automated Physical Testbed (APTB) for Wireless Systems, which is available in the authors' lab and allows a flexible setup and full control of arbitrary topologies. The results of the measurements demonstrate a very good stability and short-term with long-term performance also under dynamic conditions.}, language = {en} } @inproceedings{YushevSikoraSchappacher, author = {Yushev, Artem and Sikora, Axel and Schappacher, Manuel}, title = {Verification and Validation of 6Lo Protocol Stacks}, series = {Proceedings of the Wireless Congress 2016}, address = {M{\"u}nchen}, isbn = {978-3-645-50161-3}, pages = {903 -- 907}, language = {en} } @inproceedings{YushevSchappacherSikora, author = {Yushev, Artem and Schappacher, Manuel and Sikora, Axel}, title = {Titan TTCN-3 Based Test Framework for Resource Constrained Systems}, series = {MATEC Web Conference}, doi = {10.1051/matecconf/20167506005}, pages = {5}, abstract = {Wireless communication systems more and more become part of our daily live. Especially with the Internet of Things (IoT) the overall connectivity increases rapidly since everyday objects become part of the global network. For this purpose several new wireless protocols have arisen, whereas 6LoWPAN (IPv6 over Low power Wireless Personal Area Networks) can be seen as one of the most important protocols within this sector. Originally designed on top of the IEEE802.15.4 standard it is a subject to various adaptions that will allow to use 6LoWPAN over different technologies; e.g. DECT Ultra Low Energy (ULE). Although this high connectivity offers a lot of new possibilities, there are several requirements and pitfalls coming along with such new systems. With an increasing number of connected devices the interoperability between different providers is one of the biggest challenges, which makes it necessary to verify the functionality and stability of the devices and the network. Therefore testing becomes one of the key components that decides on success or failure of such a system. Although there are several protocol implementations commonly available; e.g., for IoT based systems, there is still a lack of according tools and environments as well as for functional and conformance testing. This article describes the architecture and functioning of the proposed test framework based on Testing and Test Control Notation Version 3 (TTCN-3) for 6LoWPAN over ULE networks.}, language = {en} } @inproceedings{ToumassianWernerSikora, author = {Toumassian, Sebouh and Werner, Rico and Sikora, Axel}, title = {Performance Measurements for Hypervisors on Embedded ARM Processors}, series = {2016 International Conference on Advances in Computing, Communications and Informatics (ICACCI)}, organization = {IEEE}, isbn = {978-1-5090-2029-4 (digital)}, doi = {10.1109/ICACCI.2016.7732152}, pages = {5}, abstract = {Due to its numerous application fields and benefits, virtualization has become an interesting and attractive topic in computer and mobile systems, as it promises advantages for security and cost efficiency. However, it may bring additional performance overhead. Recently, CPU virtualization has become more popular for embedded platforms, where the performance overhead is especially critical. In this article, we present the measurements of the performance overhead of the two hypervisors Xen and Jailhouse on ARM processors in the context of the heavy load "Cpuburn-a8" application and compare it to a native Linux system running on ARM processors.}, language = {en} } @inproceedings{Sikora, author = {Sikora, Axel}, title = {Security in Ubiquitous Communication}, series = {Wireless Communication and Information : Ubiquitous Communication}, editor = {Sieck, J{\"u}rgen}, publisher = {Verlag Werner H{\"u}lsbusch}, address = {Gl{\"u}ckstadt}, isbn = {978-3-86488-053-7}, pages = {39 -- 52}, language = {en} } @inproceedings{YushevSikora, author = {Yushev, Artem and Sikora, Axel}, title = {The overview of public key infrastructure based security approaches for vehicular communications}, series = {2nd Baden-W{\"u}rttemberg Center of Applied Research Symposium on Information and Communication Systems - SInCom 2015}, isbn = {978-3-00-051859-1}, pages = {30 -- 35}, language = {en} } @inproceedings{BetzWesthoffYushevetal., author = {Betz, Johann-Wolfram and Westhoff, Dirk and Yushev, Artem and Sikora, Axel and Walz, Andreas}, title = {2nd Baden-W{\"u}rttemberg Center of Applied Research Symposium on Information and Communication Systems - SInCom 2015}, editor = {Benyoucef, Dirk and Freudenberger, J{\"u}rgen}, isbn = {978-3-00-051859-1}, url = {http://nbn-resolving.de/urn:nbn:de:bsz:ofb1-opus4-17833}, pages = {iii, 73}, abstract = {Enth{\"a}lt die Artikel: "CPU-based Covert- and Side-Channels in Cloud Ecosystems" von Johann Betz und Dirk Westhoff, S. 19-23 "The overview of Public Key Infrastructure based security approaches for vehicular communications" von Artem Yushev und Axel Sikora, S. 30-35 "Testing Embedded TLS Implementations Using Fuzzing Techniques and Differential Testing" von Andreas Walz und Axel Sikora, S. 36-40}, language = {en} } @inproceedings{HassanSikoraKunzetal., author = {Hassan, Aneeque and Sikora, Axel and Kunz, Dominique-Stephan and Eberlein, David}, title = {Headless Android Systems for Industrial Automation and Control}, series = {Tagungsband zum Workshop der Multiprojekt-Chip-Gruppe Baden-W{\"u}rttemberg, Mannheim, Februar 2013}, volume = {49}, organization = {Hochschule Ulm}, issn = {1868-9221}, pages = {67 -- 74}, abstract = {Android is an operating system which was developed for use in smart mobile phones and is the current leader in this market. A lot of efforts are being spent to make Android available to the embedded world, as well. Many embedded systems do not have a local GUI and are therefore called headless devices. This paper presents the results of an analysis of the general suitability of Anroid in headless embedded systems and ponders the advantages and disadvantages. It focuses on the hardware related issues, i.e. to what extent Android supports hardware peripherals normally used in embedded systems.}, language = {en} } @inproceedings{SikoraLillSchappacher, author = {Sikora, Axel and Lill, Dirk and Schappacher, Manuel}, title = {Development of a Hardware-Software Co-Design for a real-time localization protocol for pedestrian safety}, series = {Tagungsband zum Workshop der Multiprojekt-Chip-Gruppe Baden-W{\"u}rttemberg, Offenburg, Februar 2012}, volume = {47}, organization = {Hochschule Ulm}, issn = {1868-9221}, pages = {47 -- 54}, abstract = {The research project Ko-TAG [2], as part of the research initiative Ko-FAS [1], funded by the German Ministry of Economics and Technologies (BMWi), deals with the development of a wireless cooperative sensor system that shall pro-vide a benefit to current driver assistance systems (DAS) and traffic safety applications (TSA). The system's primary function is the localization of vulnerable road users (VRU) e.g. pedestrians and powered two-wheelers, using communication signals, but can also serve as pre-crash (surround) safety system among vehicles. The main difference of this project, compared to previous ones that dealt with this topic, e.g. the AMULETT project, is an underlying FPGA based Hardware-Software co-design. The platform drives a real-time capable communication protocol that enables highly scalable network topologies fulfilling the hard real-time requirements of the single localization processes. Additionally it allows the exchange of further data (e.g. sensor data) to support the accident pre-diction process and the channel arbitration, and thus supports true cooperative sensing. This paper gives an overview of the project's current system design as well as of the implementations of the key HDL entities supporting the software parts of the communication protocol. Furthermore, an approach for the dynamic reconfiguration of the devices is described, which provides several topology setups using a single PCB design.}, language = {en} } @inproceedings{Sikora, author = {Sikora, Axel}, title = {Wireless Network and Gateway Architectures for Home Care Applications}, series = {"Proceedings of the 6th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications : Volume 2 ; IDAACS' 2011 "}, organization = {IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications: 6 (Prague, Czech Republic); 2011.09.15-17}, isbn = {978-1-4577-1423-8}, pages = {832 -- 836}, language = {en} } @inproceedings{RohlederJaeckelSikora, author = {Rohleder, Alexander and J{\"a}ckel, Steffen and Sikora, Axel}, title = {Design and Test of a Gigabit Ethernet MAC for High-Speed HIL-Support}, series = {Tagungsband zum Workshop der Multiprojekt-Chip-Gruppe Baden-W{\"u}rttemberg, Furtwangen, Juli 2011}, volume = {46}, publisher = {Hochschule Ulm}, address = {Ulm}, issn = {1682-9221}, pages = {35 -- 40}, abstract = {The efficient support of Hardwae-In-theLoop (HIL) in the design process of hardwaresoftware-co-designed systems is an ongoing challenge. This paper presents a network-based integration of hardware elements into the softwarebased image processing tool „ADTF", based on a high-performance Gigabit Ethernet MAC and a highly-efficient TCP/IP-stack. The MAC has been designed in VHDL. It was verified in a SystemCsimulation environment and tested on several Altera FPGAs.}, language = {en} } @inproceedings{JaeckleSikora, author = {J{\"a}ckle, Daniel and Sikora, Axel}, title = {Experiences with a telecare platform integration of ZigBee sensors into a middleware platform}, series = {6th European ZigBee Developers' Conference, 27.-28.Juni 2012, M{\"u}nchen}, organization = {European ZigBee Developers' Conference; 6 (M{\"u}nchen): 2012.05.27-28}, language = {en} } @inproceedings{BraunSikora, author = {Braun, Nathan and Sikora, Axel}, title = {Firmware update over the air for small microcontrollers}, series = {It's a smarter world : Embedded World 2011 Exhibition \& Conference ; proceedings \& conference materials ; March 1 - 3, 2011, N{\"u}rnberg, Germany}, publisher = {WEKA-Fachmedien}, address = {Poing}, organization = {Embedded World Exhibition \& Conference ; (N{\"u}rnberg) : 2011.03.01-03}, isbn = {978-3-7723-0861-1}, language = {en} } @inproceedings{KlemmSikora, author = {Klemm, Martin and Sikora, Axel}, title = {Measurement Unit for Energy Efficient M2M Mobile Communication}, series = {Multi-Projekt-Chip-Gruppe Baden-W{\"u}rttemberg : Tagungsband zum Workshop der Multiprojekt-Chip-Gruppe Baden-W{\"u}rttemberg}, volume = {38}, address = {Ulm}, organization = {Fachhochschule Ulm}, issn = {1862-7102}, pages = {41 -- 46}, language = {en} } @inproceedings{LillSikora, author = {Lill, Dirk and Sikora, Axel}, title = {Cooperative Wireless Sensing for Increased Traffic Safety}, series = {Proceedings \& conference materials ; exhibition \& conference, March 1 - 3, 2011, N{\"u}rnberg, Germany ; Proceedings and conference materials}, publisher = {WEKA-Fachmedien}, address = {Poing}, organization = {Embedded World <2011, N{\"u}rnberg>}, isbn = {978-3-7723-0861-1}, pages = {1 -- 3}, language = {en} }