Wireless embedded devices are key elements of Internet-of-Things (IoT) and industrial IoT (IIoT) applications. The complexity of these devices as well as the number of connected devices to networks increase steadily. The high intricacy of the overall system makes it error-prone and vulnerable to attacks and leads to the need to test individual parts or even the whole system. Therefore, this paper presents the concept of a flexible and distributed testbed to evaluate correct behavior in various operation or attack scenarios. It is based on the Robot Operating System (ROS) as communication framework to ensure modularity and expandability. The testbed integrates RF-jamming and measurement devices to evaluate remote attack scenarios and interference issues. An energy harvesting emulation cell is used to evaluate different real-world energy harvesting scenarios. A climatic test chamber allows to investigate the influence of temperature and humidity conditions on the system-under-test. As a testbed application scenario, the automated evaluation of an energy harvesting wireless sensor network designed to instrument automotive engine test benches is presented.

At least since the terms Internet of Things, Factories of the Future or Industrial Internet gave distinction to the modern world of communication, there is a special need for efficient test- and debug tools targeting research and development of embedded wireless sensor and actuator networks (WSAN) in industrial automation technology and other non-consumer application areas in adverse environments. Those networks usually have tighter requirements on dependability, synchronization, and real-time capability as compared applications in environmental monitoring or home automation. For WSAN research and development, testbeds are a valuable tool as they enable controlled and repeatable operation under conditions close to reality. The contribution of this Ph.D. dissertation is to design, implement and set up a test environment for embedded industrial wireless sensor actuator networks, with special focus on energy constrained network nodes. This testbed should offer an previously unattained level of insight in timing characteristics of the network and the energy behavior of a single node. It allows to make statements about limitations of the deployed WSAN technology, or to compare different WSAN solutions in an automated manner. The uniqueness of this testbed setup is due to a scalable, affordable and maintainable organization both in software as well as the structure of the used hardware components.

The idea of Internet of Things has grown into multiple dimensions, encompassing also the industrial world leading to initiatives like Factories of the Future (FoF) or Industrial Internet. Wireless Sensor and Actuator Networks (WSAN) play an important role in this professional domain. Their successful deployment in real-world applications calls for advanced testing and debugging effort in advance. This poster presents the architecture of TWECIS, a Testbed targeting the investigation of Wireless Energy Constrained Industrial Sensor and Actuator Networks. The proposed architecture tries to unite scalability, maintainability and a cost-saving design of the testbed infrastructure with the special requirements of research in industrial wireless network design.

Many applications in factory and process automation require robust wireless sensor networks (WSNs) for collecting sensor data with sampling and transmission rates up to 100 Hz from battery powered sensor nodes. To establish real-time communication in a star network topology, the LLDN mode of IEEE 802.15.4e amendment was released. We present a demonstration system which applies a recently introduced relaying method compatible to the LLDN mode, which uses dedicated relay nodes, thus increasing the reliability of the network while reducing the energy consumption of the sensor nodes. Furthermore, packet combining schemes on packets received erroneously from both, sensor node and relay node, are proposed, applied, and analyzed. Measurements with the demonstration system have shown that 96.4% of these erroneous transmissions could be recovered correctly.

In this paper, we present a highly accurate but still cost-effective measurement solution for tracking the highly dynamic power consumption of wireless embedded systems. We extended the conventional measurement of a single shunt resistor's voltage drop by using a dual shunt resistor stage with an automatic switch-over between both stages, which leads to a large dynamic measurement range of 50 dB (1μA to 100 mA) with an average measurement error smaller than 1.2 %. Using two zero-drift current sense amplifiers for measuring the voltage drop over two different sized shunt resistors together with a 16 bit SAR ADC for each of both amplifiers leads to a far better thermal noise behaviour and a higher total measurement resolution compared to a single shunt solution, providing a minimum invasive measurement system with a maximum voltage drop of 100 mV. Using a state-of-the-art Ethernet connection allows our measurement system to forward the power samples with up to 250 kHz sampling rate to any remote networked computer.

Wireless sensor and actuator networks (WSAN) for industrial applications usually have tighter requirements on dependability, synchronization, and real-time capability as compared applications in environmental monitoring or health care. For WSAN research and development, testbeds are a valuable tool as they enable controlled operation under conditions close to reality. In this contribution we present TWECIS, a testbed targeting the investigation of Wireless Energy Constrained Industrial Sensor and Actuator networks. We describe the concept, its architecture and the used hardware. Unique feature of TWECIS is the use of an industrial Real Time Ethernet system which offers the evaluation of the timing behavior of the nodes with a jitter below 100 ns. In addition TWECIS offers synchronized network-wide current measurements on all testbed nodes in a range from 1 μA to 100 mA for accurate power consumption profiling, remote and parallelized programming of nodes, remote in-circuit debugging, monitoring of UART output, and centralized storage of all captured data.

The range of applications for wireless sensor networks (WSNs) is continuously growing and is expanding into new branches and markets rapidly. Largely different requirements regarding network structure, powering possibility, latency, data rates, and reliability, lead to the need of suitable systems and protocols. An approved way to implement an energy aware wireless network is the Time Division Multiple Access (TDMA) strategy. In this work we propose two different TDMA schedules for highly reliable sensor data collection with sample rates of 10 Hz and analyze and compare them regarding reliability and energy consumption. A standard coin cell can power a sensor node for more than 2 month with a sensor data loss smaller than 10-3percent at 3% PER in the radio channel.