@misc{ChatharajupalliRottaKarnapkeetal., author = {Chatharajupalli, Navya Sneha and Rotta, Randolf and Karnapke, Reinhardt and Nolte, J{\"o}rg}, title = {Probing considered harmful : leveraging RSSI for link quality prediction}, series = {Proceedings of the IEEE 50th Conference on Local Computer Networks : LCN 2025 : October 14-16, 2025, Sydney, Australia}, journal = {Proceedings of the IEEE 50th Conference on Local Computer Networks : LCN 2025 : October 14-16, 2025, Sydney, Australia}, publisher = {IEEE}, address = {New York, NY}, isbn = {979-8-3315-3704-3}, issn = {2831-7742}, doi = {10.1109/LCN65610.2025.11146347}, pages = {1 -- 9}, abstract = {Wireless mesh protocols that use a routing metric based on throughput or airtime require predictions about future throughput for all mesh neighbors. Typically, the Wi-Fi rate controller provides this information, and state-of-the-art rate control algorithms estimate it based on statistics from past unicast transmissions. This introduces an adverse cross-layer dependency because meaningful statistics are only available for the links that were used by the routing layer. Existing implementations either ignore this, or use other routing metrics, such as distance, or generate artificial periodic probe traffic to all neighbors. Unfortunately, probing reacts slowly to changing conditions, increases the medium contention, and can lead to overly optimistic predictions. To overcome this, we introduce an RSSI-based link quality prediction for the routing layer. Benchmarks in a B.A.T.M.A.N. version V mesh show a decrease of round-trip time by three orders of magnitude and an increase of the end-to-end packet delivery ratio. TCP connections became possible over long routes that were previously unusable. Although highly imprecise, the easy to acquire RSSI provided sufficiently good predictions for our mesh network.}, language = {en} } @misc{ChatharajupalliRottaKarnapkeetal., author = {Chatharajupalli, Navya Sneha and Rotta, Randolf and Karnapke, Reinhardt and Nolte, J{\"o}rg}, title = {Animal health monitoring and tracking through solar-powered mesh network}, series = {22. GI/ITG KuVS Fachgespr{\"a}ch Sensornetze : 11. und 12. September 2025, Clausthal-Zellerfeld}, journal = {22. GI/ITG KuVS Fachgespr{\"a}ch Sensornetze : 11. und 12. September 2025, Clausthal-Zellerfeld}, publisher = {TU Clausthal-Zellerfeld}, address = {Clausthal-Zellerfeld}, doi = {10.21268/20250805-0}, pages = {1 -- 3}, abstract = {Various health and movement sensors, especially bolus sensors inside a cow's stomach, are crucial for timely medical interventions. Commonly, wall-powered gateways are used to retrieve sensor updates and forward them quickly to an analysis service. In large outdoor farmlands, however, localisation of individual cows becomes important while the long-term operation of wall-powered gateways is costly. Previous solutions that use a LoRaWAN gateway with bigger antennas are still limited to 500m and provide only poor localization information. Existing solutions based on a mesh network of repeaters provide good localization but still depend on external wall power. Solar-powered mesh nodes would simplify the long-term operation. In order to achieve this, a significant improvement of the energy efficiency of the mesh nodes is necessary. This paper explores protocol design choices for the energy-efficient communication between mesh nodes and the bolus sensors. By introducing synchronised sleep and communication intervals, the size of the solar panels and energy storage can be reduced.}, language = {en} } @misc{HerglotzJabłońskiKarnapkeetal., author = {Herglotz, Christian and Jabłoński, Ireneusz and Karnapke, Reinhardt and Shahin, Keyvan and Reichenbach, Marc}, title = {Designing intelligent sensor networks : a comprehensive survey of sensing, edge AI, and 5G+/6G connectivity}, series = {IEEE access}, volume = {13}, journal = {IEEE access}, publisher = {IEEE}, address = {Piscataway, NJ}, issn = {2169-3536}, doi = {10.1109/ACCESS.2025.3615205}, pages = {172306 -- 172325}, abstract = {With the advent of advanced transmission technologies, powerful neural-network architectures, and the availability of cheap sensing solutions, new paradigms for monitoring, controlling, and optimizing any automated system are appearing. While traditionally, sensors simply provided visual or acoustic feedback to human operators of such systems, nowadays, autonomous systems more and more rely on the automatic sensing and processing of such data to react and adapt their control mechanisms. In such complex control systems, sensor networks play a vital role. In this paper, we assess the state of the art in the three main components used within sensor networks: smart sensing elements, transmission technologies, and processing technologies. Concerning the latter, more and more artificial intelligence-based methods are developed and applied turning smart sensor networks into intelligent or even cognitive sensor networks. For the development of such sensing systems, a high variety of performance metrics could be important to the designer. This paper discusses the vast design space for intelligent sensor networks and provides guidance and directions on how to construct future intelligent sensor networks efficiently.}, language = {en} } @misc{ChatharajupalliRottaKarnapkeetal., author = {Chatharajupalli, Navya Sneha and Rotta, Randolf and Karnapke, Reinhardt and Nolte, J{\"o}rg}, title = {VibroMote : Wi-Fi-based mesh communication for railway bridge inspection and monitoring}, series = {2025 International Symposium on Networks, Computers and Communications (ISNCC)}, journal = {2025 International Symposium on Networks, Computers and Communications (ISNCC)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-6654-5769-9}, issn = {2768-0940}, doi = {10.1109/ISNCC66965.2025.11250402}, pages = {1 -- 6}, abstract = {Vibration sensing provides insights into the dynamic behaviour of engineering constructions such as railway bridges. Cable-based sensors are viable only for long-term condition monitoring and rare special inspections because of the labor-intensive deployment. Although wireless sensors significantly reduce this overhead, their energy constraints limited the network throughput and, hence, their resolution in space and time. Batteryor solar-powered sensor nodes with high network throughput would enable in-depth measurements during regular inspections and improve the access to high-quality monitoring data. We present "VibroMote", which combines energy harvesting, a high-bandwidth 3-axis MEMS accelerometer, and high-throughput, self-organizing mesh communication via IEEE 802.11 Wi-Fi. The evaluation on a real bridge with 18 VibroMotes shows that the deployment time can be reduced from hours to minutes; the multi-hop mesh provides sufficient throughput reserves for the application whereas direct one-hop communication failed; the battery runtime is sufficient for temporary measurements during inspections; and the energy consumption during sleep modes would be low enough for solar-powered long-term monitoring. Hence, the combination of high-throughput Wi-Fi with mesh networking is a strong alternative to the commonly used low-power radio technologies when long range between the sensors is not needed.}, language = {en} } @misc{KarnapkeMikhalevCotardoetal., author = {Karnapke, Reinhardt and Mikhalev, Daniil and Cotardo, Dario and During, Fabian and Kupke, David and Walther, Karsten and Mechtcherine, Viktor}, title = {Enhancing performance and increasing safety of concrete pumps through digitalization}, series = {IEEE SAS 2025 : IEEE Sensors and Applications 2025 : symposium proceedings}, journal = {IEEE SAS 2025 : IEEE Sensors and Applications 2025 : symposium proceedings}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, address = {Piscataway, NJ}, isbn = {979-8-3315-1193-7}, doi = {10.1109/SAS65169.2025.11105159}, pages = {1 -- 6}, abstract = {Modern concrete mixtures are becoming increasingly complex due to environmental and economic pressures. The use of fillers and advanced admixtures enables a reduction in cement content, which alters the properties of fresh concrete. These changes often lead to higher viscosity and increased sensitivity to temperature fluctuations and water content variations, potentially causing flow instabilities and pipeline blockages during pumping.In this paper, a sensor-based edge device is introduced that can be attached to existing concrete pumps to monitor process data and detect impending blockages. By continuously analyzing hydraulic data during the pumping process, the system assesses the material's flow behavior to identify early signs of potential blockages. These insights enable proactive interventions, improving operational safety and reducing costly disruptions.conct}, language = {en} } @misc{NattkeRottaNatarovetal., author = {Nattke, Matthias and Rotta, Randolf and Natarov, Roman and Archila, Oscar and Mykytyn, Pavlo}, title = {Precise sensors for localization in the drone swarm}, series = {Proceedings iCCC2024 - iCampµs Cottbus Conference, 2024-05-14 - 2024-05-16, Cottbus}, volume = {2024}, journal = {Proceedings iCCC2024 - iCampµs Cottbus Conference, 2024-05-14 - 2024-05-16, Cottbus}, publisher = {AMA}, isbn = {978-3-910600-00-3}, doi = {10.5162/iCCC2024/P16}, pages = {166 -- 169}, abstract = {Drones can be connected as a swarm to precisely monitor large agricultural areas and manage them more sustainable. They test sensor technology in real environments and solve complex tasks faster. Key aspects include accurate localization, reliable communication, and dynamic flight control. The localization accuracy of RTK-GNSS-enabled system, which includes GPS, GLONASS, GALILEO positioning systems is compared with Ultra-Wideband (UWB) one. The UPWARDS communication hub is presented as a processing and connection point across swarm agents. This controller also incorporates collision avoidance features and testing of evasion strategies.}, language = {en} } @inproceedings{ChatharajupalliRottaNolte, author = {Chatharajupalli, Navya Sneha and Rotta, Randolf and Nolte, J{\"o}rg}, title = {P2 - VibroMote: Energy efficient Vibration Monitoring for Railway tracks and Bridges}, series = {iCCC2024 - iCampµs Cottbus Conference 2024-05-14 - 2024-05-16}, booktitle = {iCCC2024 - iCampµs Cottbus Conference 2024-05-14 - 2024-05-16}, publisher = {AMA Service GmbH, Von-M{\"u}nchhausen-Str. 49, 31515 Wunstorf, Germany}, isbn = {978-3-910600-00-3}, doi = {10.5162/iCCC2024/P2}, pages = {123 -- 126}, abstract = {Filtering, storing, and transmitting measurements of high-resolution sensors within a limited energy budget is challenging. For instance, a 3-axis MEMS acceleration sensor for structural condition monitoring and predictive maintenance generates up to 160 kB/s at a sampling rate of 26.6 kHz. This paper discusses the design space with focus on solar harvesting solutions. VibroMote is an energy efficient sensor node that combines a multi-radio micro-controller, an ultra-low power co-processor with persistent memory, a solar harvester, and multiple energy storage options. This enables prototyping of solar-powered long-term data acquisition, in-node processing, and wireless networking for high-resolution sensors.}, language = {en} } @misc{KarnapkeRichterWerner, author = {Karnapke, Reinhardt and Richter, Martin and Werner, Matthias}, title = {Virtualization in robot swarms: past, present, and future}, series = {2024 IEEE 21st Consumer Communications \& Networking Conference (CCNC)}, journal = {2024 IEEE 21st Consumer Communications \& Networking Conference (CCNC)}, publisher = {IEEE}, isbn = {979-8-3503-0457-2}, doi = {10.1109/CCNC51664.2024.10454838}, pages = {1 -- 6}, abstract = {Robot swarms have come a long way since the first mobile sensor/actuator networks. Since then, we have seen the rise of operating systems for robots and swarm operating systems that ease the use of robots, and especially of large swarms of them, a lot. Still, the description of a task is often not easy and best done by experts. In this paper we envision future swarm operating systems, where task descriptions take a form which can be realized by non-experts. We describe our idea of hugely increased virtualization in the swarm and how this can be used to realize the aforementioned vision.}, language = {en} } @misc{GierschNguyenNolteetal., author = {Giersch, Oliver and Nguyen, Dustin and Nolte, J{\"o}rg and Schr{\"o}der-Preikschat, Wolfgang}, title = {Virtual memory revisited for tiered memory}, series = {Proceedings of the 15th ACM SIGOPS Asia-Pacific Workshop on Systems}, journal = {Proceedings of the 15th ACM SIGOPS Asia-Pacific Workshop on Systems}, publisher = {ACM}, address = {New York, NY, USA}, isbn = {979-8-4007-1105-3}, doi = {10.1145/3678015.3680475}, pages = {1 -- 7}, abstract = {The landscape of memory technologies has grown substantially more diverse and heterogeneous, with a number of special-purpose memory technologies reaching market maturity in recent years, such as NVRAM (Non-Volatile Memory), HBM (High-Bandwidth Memory) or the upcoming CXL.mem. Future computing systems will have to contend with byte-addressable and cache-coherent main memory that is highly diverse, either in terms of the fundamental performance characteristics of its underlying memory technology, or due to the fact that CXL.mem will allow accessing homogenous but remote memory. The VM (Virtual Memory) subsystems of today have been empirically optimized over decades, but were designed for a single tier of main memory only. While recent approaches that integrated tiered memory have focused on better memory access metrics to improve page placement strategies, we seek to leverage the proven heuristics that are already in place. In times of high load we assign pages from slower memory, demote inactive pages according to standard page replacement strategies and use lazy page promotions when sufficient resources are available again to retain the inherently high reactivity of demand paging with regard to working set changes. We integrate these mechanisms into the VM subsystem of a full-featured mainstream operating system (FreeBSD) with minimal adaptations. The resulting multi-tier VM system runs in a stable and efficient manner under high stress even with highly unfavorable work loads.}, language = {en} } @misc{RottaChatharajupalliNaumannetal., author = {Rotta, Randolf and Chatharajupalli, Navya Sneha and Naumann, Billy and Schulz, Julius and Karnapke, Reinhardt and Werner, Matthias and Nolte, J{\"o}rg}, title = {Demo: B.A.T.M.A.N. mesh routing on ultra low-power IEEE 802.11 modules}, series = {2024 IEEE 49th Conference on Local Computer Networks (LCN)}, journal = {2024 IEEE 49th Conference on Local Computer Networks (LCN)}, publisher = {IEEE}, isbn = {979-8-3503-8800-8}, issn = {2832-1421}, doi = {10.1109/LCN60385.2024.10639789}, pages = {4}, abstract = {When implementing multi-hop mesh network protocols, efficient direct communication, route discovery, and route repair are crucial to achieve high network throughput. To our knowledge, there is no open mesh routing protocol available for ultra low power IEEE 802.11 modules. Previous work relied on single board computers like Raspberry Pi. We implemented the B.A.T.M.A.N. mesh protocol on the popular Espressif ESP32 along with a novel hybrid rate adaptation for the selection of efficient routes. In this demo we showcase challenges and solutions related to the implementation on ESP32 and how the hybrid rate adaptation improves end-to-end throughput.}, language = {en} }